Hydraulics & Pneumatics - Hydraulics & Pneumatics is the leading international technical resource for fluid power http://hydraulicspneumatics.com/rss.xml en Improving The Reliability of Hydraulic Cylinder Position Sensors http://hydraulicspneumatics.com/cylinders-actuators/improving-reliability-hydraulic-cylinder-position-sensors <div class="field-deck"> Sponsored by Balluff </div> <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/06/Balluff_Logo-262x50.gif" style="width: 200px; height: 38px; float: right;" />Today&#39;s highly demanding industrial applications for linear position sensors in hydraulic cylinders sometimes exceed the limits of survivability for standard product designs. Heat, extreme cold, physical impact, shock, vibration, liquid ingress, corrosion, and other challenges can lead to premature sensor failure and unsatisfactory service life. Advances in specialized sensor designs and consideration for current best practices in application engineering can enhance sensor reliability and extend life expectancy in these harsh operating environments.&nbsp;</p> <script type="text/javascript"> document.write('\ <iframe style="height:685px; width: 600px" frameBorder="0" scrolling="no"\ src="http://pages.hydraulicspneumatics.com/HP_Digital_Balluff_HydraCylinSensor_WP_DC_072516?partnerref=' + getParameterByName("partnerref") + "&elq=" + getParameterByName("elq2") + "&code=" + getParameterByName("code") + "&PK=" + getParameterByName("PK") + "&PR=" + getParameterByName("PR") + '"></iframe>'); function getParameterByName(name) { var match = RegExp('[?&]' + name + '=([^&]*)').exec(window.location.search); if (match == null) return ""; return match && decodeURIComponent(match[1].replace(/\+/g, ' ')); } </script></div> http://hydraulicspneumatics.com/cylinders-actuators/improving-reliability-hydraulic-cylinder-position-sensors#comments White Papers Cylinders & Actuators Fri, 29 Jul 2016 19:57:00 +0000 39361 at http://hydraulicspneumatics.com Electronic Pressure Transducers http://hydraulicspneumatics.com/controls-instrumentation/electronic-pressure-transducers <div class="field-deck"> Sponsored by NOSHOK </div> <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/06/noshok_black_185x62logo.gif" style="width: 180px; float: right; height: 60px;" />Those working in the fluid power industry often consider themselves mechanically inclined. Concepts of pressure, force, flow, and torque are second nature. But the continuing influx of electronic components &mdash; especially transducers &mdash; into hydraulic and pneumatic systems makes knowledge of electrical terminology and concepts essential to job performance.</p> <p>Download <em><strong>FAQs on Electronic Pressure Transducers</strong></em> sponsored by <strong>NOSHOK</strong> to help explain some of the most common concerns surrounding pressure sensors, we present some common questions and direct answers.</p> <script type="text/javascript"> document.write('\ <iframe style="height:700px; width: 600px" frameBorder="0" scrolling="no"\ src="http://pages.hydraulicspneumatics.com/HP_Digital_Noshok_PressureTransducers_FAQ_DC_072116?partnerref=' + getParameterByName("partnerref") + "&elq=" + getParameterByName("elq2") + "&code=" + getParameterByName("code") + "&PK=" + getParameterByName("PK") + "&PR=" + getParameterByName("PR") + '"></iframe>'); function getParameterByName(name) { var match = RegExp('[?&]' + name + '=([^&]*)').exec(window.location.search); if (match == null) return ""; return match && decodeURIComponent(match[1].replace(/\+/g, ' ')); } </script></div> http://hydraulicspneumatics.com/controls-instrumentation/electronic-pressure-transducers#comments Design FAQs Controls & Instrumentation Tue, 26 Jul 2016 19:46:00 +0000 39301 at http://hydraulicspneumatics.com Tompkins Industries to Distribute ContiTech Parts http://hydraulicspneumatics.com/news/tompkins-industries-distribute-contitech-parts <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/tompkins-logo-440.png" style="width: 595px; height: 149px; margin: 3px;" /></p> <p>Tompkins Industries, a wholesaler of hydraulic adapters and fluid-power products, entered an agreement with Continental to distribute ContiTech hydraulic products. Based in Olathe, Kansas, Tompkins has 14 locations throughout North America.&nbsp; It holds an extensive presence in the aftermarket, and is heavily involved in the agriculture original-equipment (OE) field.&nbsp; The company provides industrial hoses and assemblies, along with a variety of hydraulic adapters and fluid-power products.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/danfoss-power-solutions-acquire-white-drive-products">Danfoss Power Solutions to Acquire White Drive Products </a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulics-pneumatics-products-week-425-52 ">Hydraulics &amp; Pneumatics Products of the Week (4/25-5/2)</a></p> <p><a href="http://hydraulicspneumatics.com/news/des-case-acquires-oilmiser-product-line">Des-Case Acquires OilMiser Product Line</a></p> </div> <p>Ryan Gocher, Continental NAFTA&rsquo;s hydraulics sales and marketing manager says, &ldquo;We are extremely pleased with the partnership and anticipate a smooth transition in the changeover process.&rdquo;</p> <p>The agreement will enable both Continental and Tompkins to expand their distribution channels in North America. Gocher adds, &ldquo;The agreement really serves as a statement to the importance and strategic value that the hydraulic hose market has to Continental.&rdquo;</p> <p>Both Tompkins and Continental anticipate that the changeover will be completed by the end of August. Terms of the agreement were not disclosed.</p> <p>For additional information on Continental and Tompkins, visit <a href="http://www.contitech.us" target="_blank">www.contitech.us</a> and <a href="http://www.tompkinsind.com" target="_blank">www.tompkinsind.com</a>, respectively.</p> </div> http://hydraulicspneumatics.com/news/tompkins-industries-distribute-contitech-parts#comments News Tue, 26 Jul 2016 18:52:00 +0000 39411 at http://hydraulicspneumatics.com AEM Releases June, Midyear Tractor and Combine Report http://hydraulicspneumatics.com/blog/aem-releases-june-midyear-tractor-and-combine-report <div class="node-body blog-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/AEM%20AG%20June%202016%20Data%205%20Year%20-%201%20BD_0.png" style="font-size: 12.8px; line-height: 20px; margin: 3px; width: 596px; height: 389px;" /></p> <p>A report on sales of small and large tractors released in May by the Association of Equipment Manufacturers (AEM) showed that the sale of small tractors under 40 HP remained high, while the sales of larger tractors continue to lag. The trade organization for off-road equipment manufacturers and suppliers also released a report in June that showed similar results, with sales of farm tractors under 40 HP up 3% compared to last year, and a year-to-date gain of 12.7%. Meanwhile, June U.S. retail sales for 2WD tractors ranging from 40 to&nbsp;100HP&nbsp;increased 2.8% since last year, but were down 1.1% year to date.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/aem-continues-review-ag-braking-requirements">AEM Continues Review of ag Braking Requirements </a></p> <p><a href="http://hydraulicspneumatics.com/news/aem-releases-ag-tractor-and-combine-report">AEM Releases Ag Tractor and Combine Report </a></p> <p><a href="http://hydraulicspneumatics.com/construction/aem-create-new-international-construction-trade-shows">AEM to create new international construction trade shows</a></p> </div> <p>Now, as 2016 hit the midyear mark, AEM reports that the overall U.S. retail sales of ag tractors and combines in the months of 2016 continue to beat the 5-year average, with small tractors continuing to lead sales.</p> <p>Meanwhile, June sales of 2WD 100+HP tractors in the U.S. declined 21.6% since last year, with year-to-date sales down 23.9%; 4WD tractors dropped 34.3% year-over-year and were down 31.3% year-to-date.</p> <p>As for June combine sales, they experienced 8% growth compared to last year, but year-to-date sales still lagged at -23.3 percent.</p> <p>&ldquo;We have passed the midyear mark for 2016 and overall, tractor sales continue to show downward trends in the larger horsepower categories, but when combined with the unit sales of smaller hp tractors, total tractor sales are tracking above the 5-year average,&rdquo; said Charlie O&rsquo;Brien, AEM senior vice president.</p> <p>&ldquo;While there have been monthly year-over-year fluctuations, currently the positive end of the market is still geared toward smaller equipment sales, which are tied to hobby farmers, landscaping (housing) and livestock. The larger production ag machinery continues to experience double-digit declines.</p> <p>&ldquo;Looking later into 2016 and&nbsp; going into 2017, it is important to consider the 2016 farm income forecasts, where the USDA foresees lower livestock receipts and higher crop receipts.&rdquo;</p> </div> http://hydraulicspneumatics.com/blog/aem-releases-june-midyear-tractor-and-combine-report#comments Agricultural News Fluid Power Talk Tue, 26 Jul 2016 18:15:00 +0000 39401 at http://hydraulicspneumatics.com NAHAD Announces New Elected Officers http://hydraulicspneumatics.com/news/nahad-announces-new-elected-officers <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/NAHAD%20LOGO%202015%20ReflexBlack.jpg" style="width: 592px; height: 96px; margin: 2px;" /></p> <p>At its recent <a href="http://nahad.org/aws/NAHAD/pt/sd/news_article/116547/_self/layout_details/false" target="_blank">annual convention</a>, <a href="http://nahad.org/aws/NAHAD/pt/sp/home_page" target="_blank">The Association for Hose &amp; Accessories Distribution</a> (NAHAD) announced its newly elected officers and board members to serve for the coming year.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/danfoss-power-solutions-acquire-white-drive-products">Danfoss Power Solutions to Acquire White Drive Products </a></p> <p><a href="http://hydraulicspneumatics.com/news/parker-hannifin-announces-new-leadership ">Parker Hannifin Announces New Leadership</a></p> <p><a href="http://hydraulicspneumatics.com/news/husco-executive-honored-wisconsin-business-leader-year">Husco Executive Honored as Wisconsin Business Leader of the Year </a></p> </div> <p>NAHAD members include companies around the world that are engaged in the distribution and manufacturing of all types of hose, tubing, couplings, fittings, clamps, and other accessories that serve the industrial marketplace. Other members may include firms that offer services and products to the industry.</p> <p>All NAHAD members commit to compliance with the <strong><em><a href="http://nahad.org/aws/NAHAD/pt/sp/code_conduct" target="_blank">NAHAD Code of Business Conduct</a></em></strong>, meaning that they&nbsp;promote high professional business and product standards, and demonstrate ethical conduct when dealing with customers, suppliers and competitors.</p> <p><strong>The newly-elected officers for 2016 &ndash; 2017 are:</strong></p> <p>Marvin M. &lsquo;Skip&rsquo; Bruce, Jr., President of Catawba Industrial Rubber Co., Inc. in Charlotte, NC. He was elected president.</p> <p>Scott A. Moss, Vice President of Moss Rubber &amp; Equipment Corporation in Benicia, CA. He was elected 1st Vice President</p> <p>Karen Brandvold, CFO of Omni Services, Inc. in Worcester, MA. She was elected 2nd Vice President.</p> <p>James J. Reilly, Region Manager of The United Distribution Group/GHX in Hahnville, LA, is the Immediate Past President.&nbsp;</p> <p><strong>Accompanied by headshots, the newly-elected board members for 2016 &ndash; 2019 are:</strong></p> <p>Jason&nbsp;<span data-scayt-lang="en_US" data-scayt-word="Westad">Westad</span>, Sr., Vice President of FORCE America, Inc. in Burnsville, MN. He is appointed&nbsp;Distributor Member.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Jason%20Westad.png" style="width: 180px; height: 271px; margin: 3px;" title="" /></p> <p>&nbsp;</p> <p>Kyle Gingrich, Vice President of Apache, Inc. in Cedar Rapids, IA. He was also&nbsp;elected&nbsp;Distributor&nbsp;Member.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Kyle%20Gingrich.png" style="margin: 2px; font-size: 12.8px; line-height: 20px; width: 180px; height: 255px; float: left;" title="" /></p> <div>&nbsp;</div> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>Rob Coffee, Vice President of&nbsp;<span data-scayt-lang="en_US" data-scayt-word="Proco">Proco</span>&nbsp;Products, Inc. in Stockton, CA. He is appointed&nbsp;Manufacturer Member.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Rob%20Coffee.jpg" style="margin: 2px; font-size: 12.8px; line-height: 20px; width: 180px; height: 270px;" title="" /></p> <p>NAHAD&nbsp;also announces that members who agree to fabricate hose assemblies in&nbsp;compliance with the&nbsp;<span data-scayt-lang="en_US" data-scayt-word="NAHAD">NAHAD</span>&nbsp;Hose Assembly Guidelines and other requirements may become members of&nbsp;<a href="http://associationdatabase.com/aws/NAHAD/pt/sp/memservices_hsi" target="_blank"><span data-scayt-lang="en_US" data-scayt-word="NAHAD's">NAHAD&#39;s</span>&nbsp;Hose Safety Institute</a>, which is&nbsp;dedicated to hose safety, quality, and reliability.&nbsp;</p> <p>For more information about&nbsp;<span data-scayt-lang="en_US" data-scayt-word="NAHAD">NAHAD</span>, visit&nbsp;<a href="file://nynyfs01/home/leah.scully/Documents/www.NAHAD.org" target="_blank">www.NAHAD.org</a>.</p> </div> http://hydraulicspneumatics.com/news/nahad-announces-new-elected-officers#comments Hose & Tubing News Tue, 26 Jul 2016 16:06:00 +0000 39391 at http://hydraulicspneumatics.com How And Why To Monitor Hydraulic Filter Condition http://hydraulicspneumatics.com/blog/how-and-why-monitor-hydraulic-filter-condition <div class="node-body blog-body"><p>Continuous monitoring of the filter elements in a hydraulic system can provide valuable clues to the performance of the filter and the condition of the system. But before discussing this, let&#39;s consider some of the advantages and disadvantages of common filter locations in a hydraulic system.<br /> <br /> <strong>Pressure filtration</strong><br /> <br /> Locating filtering media in the pressure line provides maximum protection for components located immediately downstream. Filtration rates of two microns or less are possible, due to the positive pressure available to force fluid through the media. Filter efficiency may be reduced by the presence of high flow velocities, and pressure and flow transients, which can disturb trapped particles. The major disadvantage of pressure filtration is economic. Because the housings and elements (high-collapse type) must be designed to withstand system operating pressure, pressure filtration has the highest initial and ongoing cost.<br /> <br /> <strong>Return filtration</strong><br /> <br /> The rationale for locating filtering media in the return line is this: if the hydraulic reservoir and the oil it contains start out clean and all air entering the reservoir and returning oil is adequately filtered, then fluid cleanliness will be maintained. The other advantage of the return line as a filter location is that sufficient pressure is available to force fluid through fine media - typically 10 microns, but pressure is not high enough to complicate filter or housing design. This combined with relatively low flow velocity, means that a high degree of filtering efficiency can be achieved at an economical cost. For these reasons, return line filtration is a feature of most hydraulic systems.<br /> <br /> <strong>Off-line filtration</strong><br /> <br /> Off-line filtration enables continuous, multi-pass filtration at a controlled flow velocity and pressure drop, which results in high filtering efficiency. Filtration rates of two microns or less are possible, and water removal filters and heat exchangers can be included in the circuit for total fluid conditioning. Off-line filtration has a high initial cost, although this can usually be justified on a life-of-machine cost basis.<br /> <br /> <strong>Filter condition monitoring</strong><br /> <br /> Warning of filter-bypass is typically afforded by visual or electric clogging-indicators. These devices indicate when pressure drop (delta P) across the element is approaching the opening pressure of the bypass valve (where fitted). In the case of a return filter for example, if the bypass valve opens at a delta P of 3 Bar, the clogging indicator will typically switch at 2 Bar.<br /> <br /> <strong>Advanced filter condition monitoring</strong><br /> <br /> Replacing standard clogging-indicators with differential pressure gauges or transducers enables continuous, condition monitoring of the filter element. This permits trending of fluid cleanliness against filter element pressure-drop, which may be used to optimize oil sample and filter change intervals. For example, the optimal change for a return filter in a particular system could be higher or lower than the clogging indicator switching pressure of 2 Bar.<br /> <br /> Continuous monitoring of filter pressure drop can also provide early warning of component failures and element rupture. For example, if the delta P across a pressure filter suddenly increased from 1 to 3 Bar (all other things equal), this could be an indication of an imminent failure of a component upstream or a major ingression of contamination. Similarly, a sudden decrease in delta P could indicate a rupture in the element - something that a standard clogging indicator will not warn of.<br /> <br /> <strong>Bottom line</strong>: not monitoring the condition of hydraulic filter elements can be a costly mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=smr"><strong>get &quot;Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!&quot; available for FREE download here</strong></a>.</p> </div> http://hydraulicspneumatics.com/blog/how-and-why-monitor-hydraulic-filter-condition#comments Hydraulics At Work Tue, 26 Jul 2016 04:55:00 +0000 39381 at http://hydraulicspneumatics.com Brennan Industries Acquires Truflow Hydraulic Components http://hydraulicspneumatics.com/news/brennan-industries-acquires-truflow-hydraulic-components <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/TruflowBanner12.png" style="width: 595px; height: 198px;" /></p> <p><a href="http://www.brennaninc.com/" target="_blank">Brennan Industries</a>, a manufacturer of critical flow components, announced the acquisition of Tribute Inc.&rsquo;s U.K.-based <a href="http://www.truflowhydraulic.co.uk/?__hstc=29219491.26c8659e430dc6b0620af6ebdc585e53.1467222706173.1467222706173.1467222706173.1&amp;__hssc=29219491.1.1467222706173&amp;__hsfp=276248422" target="_blank">Truflow Hydraulic Components Ltd.</a> An ISO-certified company established in 1986, Truflow specializes in 37&deg;, BSPP, and NPTF fittings and adapters. It has developed a reputation of being a leading supplier of hydraulic components in Europe.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/brennan-adds-pressure-ratings-mobile-app">Brennan adds pressure ratings to mobile app</a></p> <p><a href="http://hydraulicspneumatics.com/news/danfoss-power-solutions-acquire-white-drive-products ">Danfoss Power Solutions to Acquire White Drive Products</a></p> <p><a href="http://hydraulicspneumatics.com/news/spousal-team-takes-ownership-pirtek-space-coast-center">Spousal Team Takes Ownership of PIRTEK Space Coast Center</a></p> </div> <p>In business for over 60 years, Brennan supplies customers worldwide with more than 40,000 standard and special hydraulic fittings and adapters in sizes ranging from 1/16 to 3 inches.&nbsp;Brennan products are stocked at full-service distribution centers in Atlanta, Cleveland, Dallas, Houston, Los Angeles, Seattle, Toronto, and Shanghai.&nbsp;</p> <p>The partnership will combine Truflow&rsquo;s workforce and manufacturing and distribution capabilities with Brennan&rsquo;s expertise in the industry. According to Truflow, it will enable the company to offer an even greater range of products to customers, and it will further establish Brennan&rsquo;s presence in the U.K.</p> </div> http://hydraulicspneumatics.com/news/brennan-industries-acquires-truflow-hydraulic-components#comments News Mon, 25 Jul 2016 20:33:00 +0000 39371 at http://hydraulicspneumatics.com AEM Continues Review of ag Braking Requirements http://hydraulicspneumatics.com/news/aem-continues-review-ag-braking-requirements <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/AEM%20logo_0.jpg" style="width: 350px; height: 101px; margin: 3px; float: left;" />The Association of Equipment Manufacturers (AEM) of Milwaukee considers changes in agricultural (ag) vehicle braking requirements for North America. Michael Pankonin, Senior Director, Technical &amp; Safety Services at AEM, attests that braking requirements for towed and towing agricultural field equipment need to be updated to keep pace with current machine designs and practices.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/aem-releases-ag-tractor-and-combine-report ">AEM Releases Ag Tractor and Combine Report</a></p> <p><a href="http://hydraulicspneumatics.com/construction/aem-create-new-international-construction-trade-shows ">AEM to create new international construction trade shows</a></p> <p><a href="http://hydraulicspneumatics.com/blog/videos-give-tips-clutch-and-brake-installation">Videos Give Tips on Clutch and Brake Installation</a></p> </div> <p>A small task force of braking-system experts from North American-based equipment manufacturers along with developers and suppliers of vehicle braking systems has been comparing the current requirements in the American Society of Agricultural Engineer&rsquo;s (ASAE) S365.9 standard to the demands currently faced by equipment and practices are placing on braking systems as well as requirements from other regions of the world.</p> <p>The review of the dated North American braking standard will take the next step towards a thorough revision when manufacturers meet in mid-June. The industry-driven review has progressed to a point where a broader coalition, including manufacturers of brake components, self-propelled, towed and towing equipment, will meet to review ASAE S365.9 as it applies to agricultural equipment currently being marketed.</p> <p>The group recognizes that increases in equipment speed, weight and size along with greater congestion of U.S. roadways are placing more demands on the performance and design of agricultural equipment braking systems.</p> <p>Although much work has already been completed, Pankonin says there is still a long way to go, and many more voices are needed to take into consideration. Invitations have been extended to a broad base of interested parties in both the U.S. and Canada.</p> <p>The upcoming meeting will bring new attendees up-to-date on the current status, needs and timelines to enhance existing standards and, where possible, establish consistency with other regional standards and regulations, thereby improving manufacturing efficiencies.</p> <p>Topics to be discussed include means to resolve the concerns over the current ASAE S365.9 standard which:</p> <p>&bull; has no provision to allow towing a lightweight ag vehicle without brakes at speeds exceeding 32kph (20 mph).</p> <p>&bull; makes no distinction between commodity trailers with variable transport loads and implements with fixed transport loads.</p> <p>&bull; does not address how the brake system interfaces between towing vehicle and the towed vehicle.</p> <p>&bull; makes no provisions to warn an operator that the brake system has failed.</p> <p>&bull; does not clearly address requirements for combination braking systems (hydrostatic and friction brakes).</p> <p>&bull; increases complexity for manufacturers and users due to the misalignment with other standards around the world.</p> <p>Once agreement has been achieved, the discussions will move to the formal ASABE standardization process. For more information, contact Michael Pankonin at <a href="mailto:mpankonin@aem.org">mpankonin@aem.org</a></p> <p><em>For more information, contact Michael Pankonin, AEM senior director, technical and safety services, at <a href="mailto:mpankonin@aem.org">mpankonin@aem.org</a>, or call (414) 298-4128.&nbsp;</em></p> </div> http://hydraulicspneumatics.com/news/aem-continues-review-ag-braking-requirements#comments Agricultural News Mon, 25 Jul 2016 17:57:00 +0000 39341 at http://hydraulicspneumatics.com Principios Ingenieriles Básicos: Circuitos de Secuencia http://hydraulicspneumatics.com/blog/principios-ingenieriles-b-sicos-circuitos-de-secuencia <div class="node-body blog-body"><p class="rtejustify">Los circuitos de secuencia son aquellos en los que se mueven varios actuadores en una secuencia predeterminada. A continuaci&oacute;n se muestran tres circuitos de secuencia utilizando componentes est&aacute;ndar:</p> <p class="rtejustify"><strong><a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2014/02/Electrical.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2014/02/Electrical.png" style="width: 280px; height: 226px; margin: 10px; float: right;" title="Figura 1: Circuito de secuencia con control electrónico" /></a>Control electr&oacute;nico&nbsp;</strong>&ndash; interruptores l&iacute;mite o de tope de carrera activados por los cilindros, controlan a v&aacute;lvulas de solenoide para secuenciar el circuito mostrado en la Figura 1. El solenoide a es energizado por un bot&oacute;n para darle inicio al movimiento 1. En lo que se completa el mismo, se acciona el interruptor E para energizar al solenoide c, iniciando as&iacute; el movimiento 2. Al final del mismo, el interruptor F es accionado para energizar al solenoide b, iniciando as&iacute; el movimiento 3. Igualmente, al finalizar el mismo se acciona el interruptor G, que energiza el solenoide d, inici&aacute;ndose el movimiento 4. Las v&aacute;lvulas de secuencia evitan la ca&iacute;da de presi&oacute;n en cualquiera de los cilindros mientras el otro opera.</p> <p class="rtejustify"><strong><a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2014/02/Sequence.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2014/02/Sequence.png" style="width: 280px; margin: 10px; float: right; height: 303px;" title="Figura 2: Válvulas de secuencia" /></a>V&aacute;lvulas de secuencia</strong> &ndash; varios cilindros pueden ser conectados para moverse en secuencia en carreras de extensi&oacute;n o retorno. En el circuito mostrado en la Figura 2, una mordaza debe cerrar antes que el taladro baje. En la carrera de retorno, el taladro debe ser retirado de la pieza de trabajo antes de que abra la mordaza. Las v&aacute;lvulas de secuencia est&aacute;n acomodadas&nbsp; de manera que una vez acumulada la presi&oacute;n cuando uno de los cilindros complete su carrera, entonces la v&aacute;lvula se abra para permitir el paso de aceite al otro cilndro.</p> <p class="rtejustify"><strong><a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2014/02/Backpressure.png" target="_self"><img alt="Figura 3: Válvulas antirretorno para generar contrapresión" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2014/02/Backpressure.png" style="width: 250px; height: 347px; margin: 10px; float: left;" title="Figura 3: Válvulas antirretorno para generar contrapresión" /></a>V&aacute;lvulas antirretorno de contrapresi&oacute;n &ndash; </strong>se puede generar una secuencia en los cilindros restringiendo el flujo a uno de ellos. Un m&eacute;todo de hacerlo consiste en la utilizaci&oacute;n de v&aacute;lvulas antirretorno de contrapresi&oacute;n. Previenen el flujo hasta que una presi&oacute;n de ajuste es alcanzada. En el circuito de la Figura 3, el cilindro 1 se extiende y retrae antes del cilindro 2.</p> <p class="rtejustify">&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p><i style="color: rgb(51, 51, 51); font-family: Georgia, Times, &quot;Times New Roman&quot;, serif; font-size: 15px; line-height: 22.2px;">Ricardo Sol&oacute;rzano&nbsp;se desempe&ntilde;a como Director General de EEM Technologies Corp., un proveedor de soluciones en Hidr&aacute;ulica, Neum&aacute;tica y Automatizaci&oacute;n Industrial para los mercados de Centro, Sur Am&eacute;rica y El Caribe. Lo puede contactar al: &nbsp;+1(855)462-7633,<a href="mailto:rsolorzano@eemtechnologies.com" style="color: rgb(14, 95, 139);">rsolorzano@eemtechnologies.com</a>, <a href="http://www.eemtechnologies.com">www.eemtechnologies.com</a>.</i></p> <p><i style="color: rgb(51, 51, 51); font-family: Georgia, Times, &quot;Times New Roman&quot;, serif; font-size: 15px; line-height: 22.2px;">&iquest;Necesita elementos filtrantes o acumuladores y vejigas? Visite la tienda virtual de <a href="http://www.eemtechnologies.com/eshop">EEM eShop</a>, 24/7, amplio stock.</i></p> </div> http://hydraulicspneumatics.com/blog/principios-ingenieriles-b-sicos-circuitos-de-secuencia#comments Circuits System Design H&amp;P en tu idioma! Sun, 24 Jul 2016 16:06:00 +0000 39331 at http://hydraulicspneumatics.com Video Shows How to Collect an Oil Sample http://hydraulicspneumatics.com/blog/video-shows-how-collect-oil-sample <div class="node-body blog-body"><p><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/2P-F_s3IGys" width="560"></iframe></p> <p><a href="http://shop.hydraquip.com/default.aspx?page=home" target="_blank">Hydraquip&rsquo;s</a> newest video on its <a href="https://www.youtube.com/channel/UCg3CYmf6UxfrMi5fvzk5Baw" target="_blank">YouTube channel</a>&nbsp;describes best practices for taking accurate oil samples when testing contamination levels and composition. &nbsp;</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/pneumatic-valves/videos-demonstrates-pneumatic-control-devices ">Videos Demonstrates Pneumatic-Control Devices</a></p> <p><a href="http://hydraulicspneumatics.com/blog/videos-give-tips-clutch-and-brake-installation">Videos Give Tips on Clutch and Brake Installation</a></p> <p><a href="http://hydraulicspneumatics.com/hose-amp-tubing/motion-industries-releases-how2-instruction-video-hydraulic-hose">Motion Industries Releases &ldquo;How2&rdquo; Instruction Video on Hydraulic Hose</a></p> </div> <p>A main takeaway from the video is to only take samples where flow is turbulent. Taking a sample from a straight pipe may reduce the amount of particles in the sample, giving an inaccurate representation of the oil as a whole.</p> <p>Other videos on the channel touch upon setting primary relief valves, setting maximum flow rates in pumps, and specific products offered by Hydraquip.</p> <p>In addition to instructional and educational videos, Hydraquip also offers a free lunch-and-learn sessions for companies to learn about the best filtration methods that suits their application. In the 45 minute session, the presenters will cover the following topics:</p> <ul> <li>Effects of Contamination</li> <li>ISO Contamination &amp; Beta Ratings</li> <li>In-Plant Filtration Location &amp; Strategies</li> <li>Offline Filtration Options</li> <li>Contamination Monitoring &amp; Sampling</li> </ul> <p>Register for the Lunch-and-Learn <a href="http://preview.hs-sites.com/_hcms/preview/content/3062141061?portalId=470591&amp;_preview=true&amp;preview_key=vtjNBHCQ&amp;__hstc=20629287.1336b19e538ad1512f281c3cc66792d2.1435244543234.1467819223570.1467835110917.32&amp;__hssc=20629287.18.1467835110917&amp;__hsfp=1446857721&amp;utm_campaign=OTC+Invite+%26+CSI+HPU&amp;utm_source=hs_email&amp;utm_medium=email&amp;utm_content=31523086&amp;_hsenc=p2ANqtz-9zO4J7OxlCrY2hCDgwZrNpeAiLbilpd8IjMhLSkDq4kyttuA0CoFJUrVPL5C8y9mJ3F12RyHd_gfjDcUwY7pzlHnKmTg&amp;_hsmi=31523086" target="_blank">here</a>.</p> </div> http://hydraulicspneumatics.com/blog/video-shows-how-collect-oil-sample#comments News Fluid Power Talk Fri, 22 Jul 2016 20:31:00 +0000 39321 at http://hydraulicspneumatics.com Danfoss Power Solutions to Acquire White Drive Products http://hydraulicspneumatics.com/news/danfoss-power-solutions-acquire-white-drive-products <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/HW%20and%20EA_handshake_0.jpg" style="width: 350px; height: 271px; margin: 3px; float: left;" title="Hollis White, left, The founder of White Motor, shakes hands with Eric Alström, president of Danfoss Power Solutions." />​Danfoss Group announces that it will acquire full ownership of hydraulic-motor manufacturer <a href="http://whitedriveproducts.com/">White Drive Products Inc.</a> and integrate it into the Danfoss Power Solutions business segment. Niels B. Christiansen, President and CEO of Danfoss, explains the acquisition&rsquo;s role in increasing Danfoss&rsquo; global footprint in the hydraulic motor market, &ldquo;With White Drive Products as part of our mobile hydraulics business, we stand even stronger, in particular, in North America and China. Together, we will have an even more comprehensive and competitive product offering that our customers will benefit from.&rdquo;</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/other-components/partnership-delivers-aerospace-standard-cad-model-catalog">Partnership Delivers Aerospace-Standard CAD-Model Catalog</a></p> <p><a href="http://hydraulicspneumatics.com/news/motion-industries-acquires-missouri-power-transmission">Motion Industries Acquires Missouri Power Transmission</a></p> <p><a href="http://hydraulicspneumatics.com/news/des-case-acquires-oilmiser-product-line">Des-Case Acquires OilMiser Product Line</a></p> </div> <p>White Drive Products has a strong presence in the U.S. and China, including manufacturing facilities in Hopkinsville, Ky., and Zhenjiang, Jiangsu, China, as well as sales and distribution offices in the U.S., China, and Europe. These will add to Danfoss Power Solutions&rsquo; range of facilities in Europe. White Drive Products also has over 700 employees, and reported sales of approx. $100 million in 2015.</p> <p>&ldquo;Joining forces is a great step for both Danfoss and White Drive Products, and this is a unique growth opportunity for both organizations,&rdquo; says Rich Maddux, CEO, White Drive Products. &ldquo;Together, we will have more capacity and investment for greater innovation, market synergies, and most importantly, growth, by using our increased manufacturing footprint to expand market share.&rdquo;</p> <p>The acquisition is expected to be fully completed during the third quarter of 2016. The parties have not disclosed the purchase price or other conditions of the acquisition.&nbsp;</p> </div> http://hydraulicspneumatics.com/news/danfoss-power-solutions-acquire-white-drive-products#comments News Fri, 22 Jul 2016 16:19:00 +0000 39311 at http://hydraulicspneumatics.com FREE Webinar Aids Design of Compact Track Loader Drives http://hydraulicspneumatics.com/blog/free-webinar-aids-design-compact-track-loader-drives <div class="node-body blog-body"><p align="left" class="style3" style="font-family: Arial, Helvetica, sans-serif; font-size: 12px; line-height: normal;"><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/CTL%20dumping%20sand.jpg" style="width: 300px; height: 170px; float: right; margin-left: 4px; margin-right: 4px;" />Time is running out to sign up for a free webinar on drive selection for compact track loaders.The compact track loader (CTL) market has been growing fast thanks to the machine&#39;s versatility and high performance. As these machines move towards higher speeds and horsepower, which motor design reigns supreme?</p> <p align="left" class="style3" style="font-family: Arial, Helvetica, sans-serif; font-size: 12px; line-height: normal;">When CTLs first emerged, equipment manufacturers had to select from existing track motors, which weren&rsquo;t optimized for the machine, so compromises had to be made. Even with innovations in both direct-drive and two-stage motors, no motor technology emerged as superior.</p> <p align="left" class="style3" style="font-family: Arial, Helvetica, sans-serif; font-size: 12px; line-height: normal;">In this webinar, Todd Degler, Product Manager for Geroler motors at Eaton Hydraulics, will explain advancements in direct-drive motor technology and how they have enabled them to be used in CTLs. Key benefits are smarter, more efficient machine designs for today and the future.</p> <div class="node-body webinar-body"> <p style="font-family: verdana,arial,helvetica,sans-serif; font-size: 11px; line-height: normal;"><span class="style3" style="font-family: Arial, Helvetica, sans-serif; font-size: 12px;">The webinar will compare the benefits and limitations of direct-drive and two-stage motors in CTLs. Participants will gain a better understanding of the three critical factors that affect motor design and learn how Eaton&rsquo;s new HP50 Geroler motor addresses the issues operators experience with their current motor.</span></p> <p style="font-family: verdana,arial,helvetica,sans-serif; font-size: 11px; line-height: normal;">The webinar will be broadcast live at 11:00 EDT on Thursday, July 28. However, if your schedule prohibits you from attending the live webinar, you can catch an archived version after that.</p> <p style="font-family: verdana,arial,helvetica,sans-serif; font-size: 11px; line-height: normal;"><em><a href="/webinar/direct-drive-vs-two-stage-motors-which-technology-should-be-your-next-ctl" target="_blank"><strong>Click here</strong></a> to go to the registration page for this free webinar.</em></p> </div> </div> http://hydraulicspneumatics.com/blog/free-webinar-aids-design-compact-track-loader-drives#comments Construction Hydraulic Pumps & Motors The Hitch Post Fri, 22 Jul 2016 13:33:00 +0000 39291 at http://hydraulicspneumatics.com How To Store Hydraulic Cylinders - Part 2 http://hydraulicspneumatics.com/blog/how-store-hydraulic-cylinders-part-2 <div class="node-body blog-body"><p>In my <a href="http://hydraulicspneumatics.com/blog/how-store-hydraulic-cylinders-safely">previous post</a>, I discussed the procedure I use when preparing hydraulic cylinders for storage. In response to it, one of our members posed this question:<br /> <br /> <em>&quot;One issue I feel you left out of the cylinder storage issue is the orientation question. How should a hydraulic cylinder be orientated for short term or long term storage? Our company repairs and evaluates hydraulic cylinders and their associated failures. We try to provide solutions for breakdowns as well as repairing those that have failed. We evaluate and repair approximately 1000 cylinders annually.<br /> <br /> One common issue has been seal failure particularly in large pneumatic and hydraulic cylinders. We have found that allowing cylinders to lay flat has a direct effect on piston and rod seal failures. We have instituted a cylinder storage standard that adheres to your recommendations as far as ports plugged, rods wrapped but in addition mandates that all cylinders are stored vertically - in such a position as not to distort or place the weight of the cylinder on the rod seals. This verticality also helps the piston seals. I wouldn&#39;t mind hearing your argument on this issue.&quot;</em><br /> <br /> Hmmm. I intentionally didn&#39;t mention it because I didn&#39;t want to do anything to perpetuate this myth. Because based on my experience, that&#39;s exactly what it is. Two cases I was indirectly involved in come to mind. In both cases the cylinders in question were off 400-ton mining-size hydraulic excavators. We are talking here about cylinders that weigh between two and three tons. And the piston rod typically weighs well over a ton by itself.<br /> <br /> So you have a situation where big, expensive, high-pressure hydraulic cylinders are suffering premature rod-seal failures. In both cases, the machine operators sought the advice of &quot;seal experts&quot;. The recommendation of these supposed experts was to store the cylinders vertically.<br /> <br /> Let&#39;s consider the reality of this nonsense:<br /> <br /> Someone drops a three ton cylinder with a closed length of four meters at your feet and tells you to store it vertically - so it doesn&#39;t fall over and destroy itself - or worse still, kill someone. Not a five-minute job, but possible I suppose.<br /> <br /> A truck arrives to transport the cylinder to a remote mine-site. The route consists of 1,000 miles of rough, unsealed road. Given you have gone to the trouble of storing the cylinder vertically in the warehouse, surely you must insist that it is transported in the same orientation? I mean, if it can&#39;t be stored horizontally in a shed, then surely the pounding it is going to get if it&#39;s laid down on the back of a truck will turn the seals into mush, right? The truck driver thinks you&#39;re crazy but he doubles his rate and obliges anyway.<br /> <br /> The cylinder arrives at the mine-site in the mandated vertical position. Trouble is, it&#39;s a stick cylinder so it&#39;s orientation on the machine is horizontal. If the bearing bands on the piston and in the gland can&#39;t adequately support the piston rod and prevent it from distorting the seals when the cylinder is sitting in a shed or bouncing around on the back of a truck, how on earth will it cope with the thrust developed when it goes into service on a 400-ton excavator?<br /> <br /> Common sense would tend to suggest that if the bearing bands have sufficient area and are correctly tolerenced to adequately support load-induced thrust without distorting the seals, then surely they will cope with the static weight of the piston-rod in storage and any dynamic loading that may occur during transport?<br /> <br /> Whether you agree with this assessment or not, you know troubleshooting is a process of elimination. So when seal failures continue to occur even after the cylinders have been stored vertically ... well it&#39;s safe to say that&#39;s not the root cause of the problem. And that was the outcome in the two situations I mentioned above. No surprise to me.<br /> <br /> So by all means, store spare hydraulic cylinders vertically if you can do so SAFELY and without any significant expense. But going to a lot of trouble and expense to do it can be a costly mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=smr"><strong>get &quot;Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!&quot; available for FREE download here</strong></a>.</p> </div> http://hydraulicspneumatics.com/blog/how-store-hydraulic-cylinders-part-2#comments Hydraulics At Work Mon, 18 Jul 2016 23:24:00 +0000 39281 at http://hydraulicspneumatics.com Designing and Applying Multi-Passage Soft-Seal Rotating Unions http://hydraulicspneumatics.com/fittings-couplings/designing-and-applying-multi-passage-soft-seal-rotating-unions <div class="field-deck"> Sponsored by Deublin </div> <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/06/DEUBLIN_Logo-262x50.gif" style="width: 200px; height: 38px; float: right;" />What is the purpose of using a multi-passage rotating union? What are a few of the main applications for multi-passage unions? What are the most important things to know when specifying unions in general? What is the primary concern when designing a multi-passage union? What sealing solutions are available for high temperatures and pressures?&nbsp;</p> <p>Download<em><strong> FAQs on Designing and Applying Multi-Passage Soft-Seal Rotating Unions</strong></em> sponsored by <strong>Deublin</strong> to get the answers to these questions and more.</p> <script type="text/javascript"> document.write('\ <iframe style="height: 800px; width: 100%; border:0;” frameBorder="0" scrolling="no"\ src="http://pages.hydraulicspneumatics.com/HP_Digital_Deublin_MultiPassSoft-SealRotatingUnion_WP_JR_071216?partnerref=' + getParameterByName("partnerref") + "&elq=" + getParameterByName("elq2") + "&code=" + getParameterByName("code") + "&PK=" + getParameterByName("PK") + "&PR=" + getParameterByName("PR") + '"></iframe>'); function getParameterByName(name) { var match = RegExp('[?&]' + name + '=([^&]*)').exec(window.location.search); if (match == null) return ""; return match && decodeURIComponent(match[1].replace(/\+/g, ' ')); } </script></div> http://hydraulicspneumatics.com/fittings-couplings/designing-and-applying-multi-passage-soft-seal-rotating-unions#comments Design FAQs Fittings & Couplings Mon, 18 Jul 2016 16:57:00 +0000 39241 at http://hydraulicspneumatics.com Actualización de Equipos Hidráulicos Revive Prensa de Extrusión http://hydraulicspneumatics.com/blog/actualizaci-n-de-equipos-hidr-ulicos-revive-prensa-de-extrusi-n-0 <div class="node-body blog-body"><p class="rtejustify">Los fabricantes de partes de aluminio est&aacute;n evaluando el desempe&ntilde;o de sus prensas de extrusi&oacute;n debido a las exigencias por respuestas r&aacute;pidas y tama&ntilde;os de &oacute;rdenes m&aacute;s peque&ntilde;os por parte de fabricantes de veh&iacute;culos, proveedores de partes aeroespaciales, fabricantes de ventanas y puertas y otros usuarios de vol&uacute;menes altos.<a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/Fig1br_0.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/Fig1br_0.png" style="width: 250px; margin: 10px; float: right; height: 171px;" title="Figura 1: Si el marco de la prensa está en buenas condiciones, una retro adaptación y actualización de componentes clave de la prensa como lo son los hidráulicos y de control, pueden extender la vida útil e incrementar la productividad de la misma (favor presione para agrandar la imagen)." /></a></p> <p class="rtejustify">Estas condiciones, junto con la consolidaci&oacute;n por parte de proveedores de formas de aluminio, est&aacute;n generando demandas adicionales en las prensas. Cuando los fabricantes de partes consolidan, generalmente distribuyen mayor cantidad de trabajo a una prensa y maximizan su utilizaci&oacute;n, lo que puede forzar a la m&aacute;quina, en particular una que tenga tiempo.</p> <p class="rtejustify">Aunque algunos fabricantes piensen en reemplazar por completo una prensa existente para cumplir con las demandas del mercado, esta inversi&oacute;n tan pesada podr&iacute;a no ser necesaria. Si la estructura de la prensa est&aacute; en buenas condiciones, efectuar una retro adaptaci&oacute;n y actualizaci&oacute;n de componentes clave en la misma, como lo son los hidr&aacute;ulicos y controles, pueden extender la vida &uacute;til y proporcionar una soluci&oacute;n m&aacute;s flexible, confiable y productiva a largo plazo.</p> <p class="rtejustify"><strong>La Retro-adaptaci&oacute;n Ofrece Ventajas de Valor a Largo Plazo</strong></p> <p class="rtejustify">El costo de una prensa de extrusi&oacute;n de alta capacidad nueva puede alcanzar los 2 millones de d&oacute;lares o m&aacute;s, dependiendo de la capacidad (m&aacute;s los costos de instalaci&oacute;n); mientras que los costos de una retro adaptaci&oacute;n t&iacute;pica puede llegar a la mitad del costo de reemplazo.</p> <p class="rtejustify">En retro-adaptaciones, los componentes de sistemas hidr&aacute;ulicos y de control se analizan para identificar oportunidades de aplicaci&oacute;n de tecnolog&iacute;as m&aacute;s eficientes y de &uacute;ltima generaci&oacute;n que permitan una mejora en el desempe&ntilde;o. Estas incluyen controles, como lo &uacute;ltimo en PLC&acute;s e interfaces HMI&acute;s, controladores de circuito cerrado y sistemas hidr&aacute;ulicos como la estaci&oacute;n de bombeo, v&aacute;lvulas (tanto en l&iacute;nea como en bloques de mando), y la tuber&iacute;a de conexi&oacute;n.</p> <p class="rtejustify">Los beneficios de una retro-adaptaci&oacute;n incluyen:</p> <ul> <li class="rtejustify">Impacto m&iacute;nimo en el sistema y en tiempos muertos,</li> <li class="rtejustify">Maximizaci&oacute;n de la vida operativa de componentes mayores de la prensa, como por ejemplo el marco, que suelen ser sumamente costosos,</li> <li class="rtejustify">Mayor productividad, facilidad de resoluci&oacute;n de fallas y mayor precisi&oacute;n de lar partes,</li> <li class="rtejustify">Mejores condiciones operativas y mayor facilidad de mantenimiento.</li> </ul> <p class="rtejustify">Cada operaci&oacute;n de prensado es &uacute;nica, y la vida &uacute;til y el desempe&ntilde;o de la prensa puede variar en gran medida. Por lo tanto, cuando se consideren retro-adaptaciones de sistemas hidr&aacute;ulicos y de control, se sugiere evaluar los siguientes factores para determinar el alcance y beneficios de un proyecto de este tipo.</p> <p class="rtejustify"><strong>Primer Factor: Nivel Actual de Control de Extrusi&oacute;n</strong></p> <p class="rtejustify">Considere su nivel actual de control de extrusi&oacute;n: &iquest;cu&aacute;n preciso es? &iquest;cu&aacute;l es la tasa de p&eacute;rdida? &iquest;cu&aacute;nto tiempo y esfuerzo toma lograr la fabricaci&oacute;n de partes de calidad y tasa baja de defectos consistentemente, sin la necesidad de intervenci&oacute;n de un operador? Si el producto de la prensa debe ser desechado debido a una calidad inaceptable, entonces probablemente requiera de mejores controles electrohidr&aacute;ulicos.<a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/fig1b.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/fig1b.png" style="width: 250px; height: 253px; margin: 10px; float: right;" title="Figura 2: Válvulas hidráulicas proporcionales ofrecen muchas ventajas sobre las de vieja generación tipo servo." /></a></p> <p class="rtejustify">Muchas prensas de extrusi&oacute;n utilizan interruptores o dispositivos anal&oacute;gicos para controlar&nbsp;los ciclos hidr&aacute;ulicos. Estos sistemas pueden limitar la productividad y contribuir a la p&eacute;rdida. Los controladores PLC de hoy en d&iacute;a y sistemas de circuito cerrado de control de bombas permiten un control m&aacute;s fino y preciso, ya sea en casos que el operador utilice la velocidad de prensado o temperatura de la parte para regular la productividad de la extrusi&oacute;n. Un sistema de control con arquitectura mejorada permite obtener una mayor precisi&oacute;n y automatizaci&oacute;n de los circuitos hidr&aacute;ulicos, logrando as&iacute; mejores niveles de control de posici&oacute;n, velocidad y puntos tope. Estos controles tambi&eacute;n permiten el ajuste durante el ciclo de extensi&oacute;n manteniendo as&iacute; la producci&oacute;n en marcha durante el mismo. Al obtener una mayor precisi&oacute;n en la extrusi&oacute;n tambi&eacute;n se gana mayor control sobre la longitud l&iacute;mite, ayudando as&iacute; a reducir el desecho de aluminio y aumentar el n&uacute;mero de formas fabricadas por hora.</p> <p class="rtejustify"><strong>Segundo Factor: La Eficiencia y Efectividad del Sistema Hidr&aacute;ulico</strong></p> <p class="rtejustify">Eval&uacute;e la eficiencia y confiabilidad de sus sistemas hidr&aacute;ulicos y de control. Probablemente est&eacute; utilizando componentes menos eficientes y m&aacute;s problem&aacute;ticos que est&eacute;n reduciendo la productividad de su operaci&oacute;n. Por ejemplo, muchas prensas de generaci&oacute;n antigua utilizan servo v&aacute;lvulas para controlar las bombas hidr&aacute;ulicas y la velocidad de prensado. Estas v&aacute;lvulas son generalmente costosas y requieren que el fluido hidr&aacute;ulico cuente con un sistema de filtraci&oacute;n con un nivel de part&iacute;culas m&aacute;s fino que el del sistema convencional. Si el filtro se degrada debido al uso, o si los sistemas de filtraci&oacute;n no son correctamente mantenidos, las v&aacute;lvulas servo se tapan f&aacute;cilmente, causando una&nbsp; perturbaci&oacute;n en el proceso de extrusi&oacute;n.</p> <p class="rtejustify">En cambio, la &uacute;ltima generaci&oacute;n de v&aacute;lvulas hidr&aacute;ulicas proporcionales ofrecen la misma (y a veces mejor) funcionalidad que una v&aacute;lvula servo en el circuito hidr&aacute;ulico, y tienen una tolerancia mucho mayor a variaciones en la calidad del fluido hidr&aacute;ulico. Esto no significa que se puede ignorar la filtraci&oacute;n; como hemos comentado en otras oportunidades <a href="http://hydraulicspneumatics.com/blog/filtraci-n-fina-previene-fallas-en-sistemas-hidr-ulicos">(ver art&iacute;culo sobre Filtraci&oacute;n Fina)</a>, &eacute;sta representa uno de los elementos m&aacute;s importantes para que un sistema tenga una larga vida &uacute;til. En nuestro ejemplo, si las v&aacute;lvulas reguladoras de la bomba no son tan resistentes, o exigiesen mantenimiento constante que por ende cause tiempos muertos de la prensa, entonces una retro-adaptaci&oacute;n que incorpore v&aacute;lvulas proporcionales podr&iacute;a reducir los costos operativos.</p> <p class="rtejustify">Los sistemas hidr&aacute;ulicos pueden adem&aacute;s ser simplificados y por ende hacerlos m&aacute;s f&aacute;ciles de operar y mantener, reemplazando dise&ntilde;os de v&aacute;lvulas en l&iacute;nea con bloques de mando hidr&aacute;ulicos. Esto permite una consolidaci&oacute;n del dise&ntilde;o hidr&aacute;ulico, reduce el n&uacute;mero de puntos potenciales de fuga (y mantenimiento), y tambi&eacute;n puede reducir el n&uacute;mero de partes de reemplazo a mantener en inventario para mantener la prensa operativa.</p> <h2 class="rtejustify"><a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/Fig3br.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/Fig3br.png" style="width: 600px; margin: 10px; height: 192px;" title="Figura 3: Los controladores PLC y de circuito cerrado de bombas permiten obtener una gran precisión y el efectuar ajustes durante el ciclo de extrusión para así mantener la productividad." /></a></h2> <p class="rtejustify"><strong>Tercer Factor: Eficiencia Energ&eacute;tica</strong></p> <p class="rtejustify">Otro reto para las f&aacute;bricas de extrusi&oacute;n de aluminio es el reducir el consumo energ&eacute;tico en su operaci&oacute;n sin sacrificar productividad.</p> <p class="rtejustify">Una oportunidad de retro adaptaci&oacute;n en este sentido est&aacute; en evaluar el motor el&eacute;ctrico que acciona a las bombas hidr&aacute;ulicas. En muchos sistemas antiguos, estos motores tend&iacute;an a ser sobredimensionados para compensar por ineficiencias aguas abajo en el sistema hidr&aacute;ulico (fugas, ca&iacute;das de presi&oacute;n). Nuevas regulaciones como por ejemplo el <em>Energy Independence and Security Act of 2007 (EISA 2007), </em>exige que los sistemas de manufactura sean dimensionados de la manera correcta y utilizando motores que sean m&aacute;s eficientes.</p> <p class="rtejustify"><a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/fig4br_1.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/fig4br_1.png" style="width: 250px; height: 349px; margin: 10px; float: right;" title="Figura 4: Los sistemas electrohidráulicos de nueva generación permiten el control más preciso, lo que minimiza esfuerzos sobre la prensa durante el ciclo de extrusión." /></a>Estos motores pueden ser utilizados en conjunto con un concepto de dise&ntilde;o de sistemas denominado: <em>energy on demand, </em>&nbsp;o energ&iacute;a cuando sea requerida, el cual integra controles sofisticados y bombas de velocidad variable con motores correctamente dimensionados para entregar solo la energ&iacute;a que se requiera para completar el ciclo de la prensa.</p> <p class="rtejustify">Vale la pena tambi&eacute;n evaluar la eficiencia de las bombas utilizadas. Todas las bombas utilizan una porci&oacute;n del flujo para lubricaci&oacute;n interna. Para generar la fuerza requerida en una secuencia de movimiento, m&aacute;s energ&iacute;a se deber&aacute; obtener del motor que acciona la bomba para compensar por esta p&eacute;rdida. Las bombas de generaci&oacute;n vieja tienen menos eficiencia y por ende requieren de mayor lubricaci&oacute;n. Tambi&eacute;n generan m&aacute;s calor, lo que sobrecarga los sistemas de enfriamiento y conllevan un consumo de energ&iacute;a innecesario.</p> <p class="rtejustify">La &uacute;ltima generaci&oacute;n de bombas hidr&aacute;ulicas es m&aacute;s eficiente y requiere menos lubricaci&oacute;n, que por ende implica lo contrario que lo mencionado anteriormente, por lo que permiten una reducci&oacute;n en el consumo de energ&iacute;a. Adem&aacute;s incluyen sensores integrados y p&oacute;rticos de diagn&oacute;stico para verificar la presi&oacute;n del sistema.</p> <p class="rtejustify"><strong>Cuarto Factor: El Ambiente de Trabajo</strong></p> <p class="rtejustify">La seguridad para el operador de la m&aacute;quina y para la prensa en s&iacute; tienen m&aacute;s importancia en el ambiente actual de manufactura. Las prensas m&aacute;s viejas podr&iacute;an no manejar estos aspectos de seguridad industrial tan bien como los sistemas de control actuales. Por ejemplo, los sistemas nuevos permiten una configuraci&oacute;n de l&iacute;mites superiores de presi&oacute;n para cada molde en la prensa para as&iacute; protegerlo de da&ntilde;o (as&iacute; como tambi&eacute;n a los otros componentes). Al actualizar los controles se puede obtener una seguridad industrial mejorada y extender la vida &uacute;til del equipo a la misma vez.</p> <p class="rtejustify"><a href="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/fig5br_1.png" target="_self"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2013/07/fig5br_1.png" style="width: 250px; height: 346px; margin: 10px; float: left;" title="Figura 5: Los sistemas hidráulicos pueden ser simplificados al reemplazar válvulas en línea por bloques de mando, simplificando así su operación y mantenimiento." /></a>Otras quejas asociadas con los sistemas hidr&aacute;ulicos de prensas de extrusi&oacute;n son las fugas y el ruido. Las fugas crean peligros como lo son pisos resbalosos, sucio y hasta riesgos de incendio. Adem&aacute;s, las fugas persistentes requieren de un reemplazo frecuente del aceite en los tanques, lo cual resulta costoso. La mayor&iacute;a del ruido asociado a sistemas hidr&aacute;ulicos en prensas, proviene de los motores de alta potencia que accionan a las bombas, as&iacute; como tambi&eacute;n de &eacute;stas.</p> <p class="rtejustify">Generalmente se asume que estos problemas vienen con la potencia y din&aacute;mica que s&oacute;lo la hidr&aacute;ulica puede lograr &ndash; inclusive si implica una necesidad mayor de mantenimiento y un ambiente de operaci&oacute;n inadecuado. Muchos de ellos resultan de sistemas antiguos, mal mantenidos o dise&ntilde;ados inapropiadamente, lo cual por supuesto puede ser f&aacute;cilmente resuelto a trav&eacute;s de una retro adaptaci&oacute;n. Por ejemplo: las prensas que utilizan v&aacute;lvulas en l&iacute;nea tienen m&aacute;s sellos y puntos de fuga que sistemas con bloques de mando.</p> <p class="rtejustify">Adem&aacute;s, limitaciones en los sistemas de control o controladores antiguos, podr&iacute;an introducir niveles altos de golpe hidr&aacute;ulico a trav&eacute;s del ciclo de prensado, lo que fatiga a las v&aacute;lvulas y sellos. Los sistemas electrohidr&aacute;ulicos modernos ofrecen un nivel de control m&aacute;s fino, lo que minimiza &eacute;ste golpe sobre el sistema. Para reducir el ruido, simples carcasas de bombas y motores o la reorientaci&oacute;n de grupos bomba-motor para redirigirlo pueden resolver esta situaci&oacute;n con una inversi&oacute;n m&iacute;nima.</p> <p class="rtejustify"><strong>Quinto Factor: Costos Operativos</strong></p> <p class="rtejustify">Muchos operadores de prensas constantemente invierten tiempo y recursos en reparaciones repetitivas y esfuerzos de mantenimiento. Estos incluyen el mantener repuestos en inventario, contratos de servicio y reparaci&oacute;n con proveedores externos de hidr&aacute;ulica y controles, y ciclos de mantenimiento m&aacute;s frecuentes &ndash; lo que por ende reduce la disponibilidad de las prensas. Estos costos no solo se relacionan con tiempo y materiales, sino tambi&eacute;n con oportunidad. Existe un riesgo mayor de perder un negocio potencial con operaciones de extrusi&oacute;n menos eficientes o propensas a tener problemas. Equipo nuevo&nbsp; podr&iacute;a aliviar estos problemas, pero los mismos pueden ser resueltos con un costo significativamente menor a trav&eacute;s de una retro adaptaci&oacute;n.</p> <p class="rtejustify">Un objetivo clave es el de tambi&eacute;n reducir el ciclo muerto de la prensa, que es aqu&eacute;l en el cual no se est&aacute;n fabricando partes. Una retro adaptaci&oacute;n hidr&aacute;ulica y de controles tiene tambi&eacute;n el potencial de reducir considerablemente &eacute;stos tiempos.</p> <p class="rtejustify"><strong>Revitalizaci&oacute;n de las Prensas de Extrusi&oacute;n</strong></p> <p class="rtejustify">El preservar y extender el valor de equipo de manufactura existente tiene mucho sentido, el reto est&aacute; en determinar la soluci&oacute;n que ofrezca un retorno confiable y mesurable sobre la inversi&oacute;n. El tiempo y desempe&ntilde;o de los sistemas existentes requieren ser analizados. Aunque no hay factor individual que pueda justificar por s&iacute; solo una retro adaptaci&oacute;n, tiene sentido considerar todos los aspectos que afectan el desempe&ntilde;o, disponibilidad y calidad de las partes de una prensa de extrusi&oacute;n.</p> <p class="rtejustify">Tambi&eacute;n es l&oacute;gico consultar con los expertos dise&ntilde;ando y efectuando retro adaptaciones de sistemas hidr&aacute;ulicos y de control de alta eficiencia para prensas: con seguridad encontrar&aacute; ineficiencias en su plataforma de producci&oacute;n que podr&iacute;an ser atendidas de inmediato.</p> <p class="rtejustify"><i>Art&iacute;culo originalmente publicado por Jeff Grube, Gerente de Segmento: Prensas e Industria Pesada en Bosch Rexroth Corp.</i></p> <p><i>Ricardo Sol&oacute;rzano&nbsp;se desempe&ntilde;a como Director General de EEM Technologies Corp., un proveedor de soluciones en Hidr&aacute;ulica, Neum&aacute;tica y Automatizaci&oacute;n Industrial para los mercados de Centro, Sur Am&eacute;rica y El Caribe. Lo puede contactar al: &nbsp;+1(855)462-7633, <a href="mailto:rsolorzano@eemtechnologies.com">rsolorzano@eemtechnologies.com</a>, www.eemtechnologies.com.</i></p> <p>&nbsp;</p> <p class="rtejustify">&nbsp;</p> </div> http://hydraulicspneumatics.com/blog/actualizaci-n-de-equipos-hidr-ulicos-revive-prensa-de-extrusi-n-0#comments Other Industries H&amp;P en tu idioma! Mon, 18 Jul 2016 14:29:00 +0000 39271 at http://hydraulicspneumatics.com Motion Industries Expands Dallas Distribution Center http://hydraulicspneumatics.com/news/motion-industries-expands-dallas-distribution-center <div class="node-body article-body"><p>Work is underway at Motion Industries&rsquo; distribution center (DC), located in Dallas, Texas, to enlarge the facility to provide a deeper selection of vendors, industrial supplies, and product lines. The company, a distributor of maintenance, repair, and operation replacement parts, has more than 550 company locations across North America in addition to 65 Motion Industries branches. The expanded facility and planned increase in inventory is also expected to generate more material-handling jobs.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/motion-control-supplier-offers-new-tool-suite-part-website-relaunch">Motion-Control Supplier Offers New Tool Suite as Part of Website Relaunch</a></p> <p><a href="http://hydraulicspneumatics.com/news/motion-industries-acquires-missouri-power-transmission ">Motion Industries Acquires Missouri Power Transmission </a></p> <p><a href="http://hydraulicspneumatics.com/news/motion-industries-restructures-top-organizational-positions">Motion Industries Restructures Top Organizational Positions </a></p> </div> <p>The new two-story DC will house distribution-center offices, Motion&#39;s Southwest division offices, a full-scale branch with retail space, and an enhanced showcase area for visitors. Almost 50,000 square feet will be added to the new facility, increasing its size to 156,000 square feet with approximately 50,000 stock keeping units. The DC is scheduled to open in March 2017 in the center of the DFW (Dallas-Fort Worth) Metroplex. The new address of the building site will be 200 W. Trinity Boulevard, Grand Prairie, Texas.</p> <p>Motion Industries will also transfer build-shop capabilities from another DC to the new facility. Services will include fluid-power conversion, gearbox assembly, cutting rails and shafting, and valve assembly. The Motion team also plans to add a bore-to-size lathe at the Dallas DC and increase shafting and rail stock. According to the company, these capabilities should help accelerate time-to-market for various products.</p> <p>Dan Krska, the manager of the new facility says, &quot;Our external customers in this region will hopefully benefit from our improved and expanded inventories, which will be available under one roof and reduce freight costs.&quot;</p> <p>Richard Burmester, Senior Vice President and Group Executive of Motion Industries&#39; Southwest Division, adds, &quot;We are very much looking forward to delivering a new high-efficiency supply-chain experience to our customers, to our branches, and to the employees of this DC.&quot;</p> </div> http://hydraulicspneumatics.com/news/motion-industries-expands-dallas-distribution-center#comments Applications News Thu, 14 Jul 2016 20:05:00 +0000 39251 at http://hydraulicspneumatics.com E-book Serves Up Tips on Pneumatic-Circuit Design http://hydraulicspneumatics.com/news/e-book-serves-tips-pneumatic-circuit-design <div class="node-body article-body"><p>&ldquo;Pneumatics: A Practical Guide&rdquo; covers the basics of the technology along with the &ldquo;why&rdquo; and &ldquo;how&rdquo; pneumatics are implemented. Available as a free download, the e-book also provides detailed information about designing pneumatic systems. It includes stories about AutomationDirect customers that used pneumatics in various DIY home applications and manufacturing.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/other-components/partnership-delivers-aerospace-standard-cad-model-catalog ">Partnership Delivers Aerospace-Standard CAD-Model Catalog </a></p> <p><a href="http://hydraulicspneumatics.com/technologies/manual-gives-hard-facts-ideal-cushioning ">Manual Gives the Hard Facts on &ldquo;Ideal Cushioning&rdquo;</a></p> <p><a href="http://hydraulicspneumatics.com/rail-truck-bus/read-hydraulic-systems-work-trucks">Read Up on Hydraulic Systems for Work Trucks</a></p> </div> <p>Practical topics in the e-book include pneumatic circuit symbols, air preparation, actuator and cylinder basics, specifying tubing and fittings, and system-design considerations. Component capabilities, controls, and efficiency are addressed as well. The book also goes beyond strictly pneumatics with discussion of electro-pneumatic systems.</p> <p>To learn more and/or to download &ldquo;Pneumatics: A Practical Guide&rdquo;, visit: <a href="http://library.automationdirect.com/practical-guide-to-pneumatics">http://library.automationdirect.com/practical-guide-to-pneumatics</a>.&nbsp;</p> </div> http://hydraulicspneumatics.com/news/e-book-serves-tips-pneumatic-circuit-design#comments News Thu, 14 Jul 2016 15:03:00 +0000 39231 at http://hydraulicspneumatics.com Spousal Team Takes Ownership of PIRTEK Space Coast Center http://hydraulicspneumatics.com/news/spousal-team-takes-ownership-pirtek-space-coast-center <div class="node-body article-body"><p align="left">In a special grand-opening celebration and ribbon cutting that took place in June,&nbsp;<span data-scayt-lang="en_US" data-scayt-word="PIRTEK">PIRTEK</span>&nbsp;Space Coast&rsquo;s service-and-supply center based in&nbsp;<span data-scayt-lang="en_US" data-scayt-word="Rockledge">Rockledge</span>, Florida announced new operation under &ldquo;power couple&rdquo; Dan and Karin&nbsp;<span data-scayt-lang="en_US" data-scayt-word="Ferretti">Ferretti</span>.</p> <p align="left">&ldquo;When the corporate office made this location available, we immediately raised our hands,&rdquo; says Dan&nbsp;<span data-scayt-lang="en_US" data-scayt-word="Ferretti">Ferretti</span>. &ldquo;The rest is history.&rdquo; The&nbsp;<span data-scayt-lang="en_US" data-scayt-word="Rockledge">Rockledge</span>&nbsp;location operated as a corporate-run center since 2002. Though it will continue to serve the hydraulic-hose maintenance and repair needs of the Brevard County area, the couple expressed plans to pursue customers in a number of different industries on Florida&rsquo;s Space Coast. These include construction, port and marine, defense, salt mining, and transportation.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/seals/knowledge-center-hub-offers-educational-media-sealing-tech ">Knowledge Center Hub Offers Educational Media on Sealing Tech</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-filters/proper-filtration-cuts-operating-costs">Proper filtration cuts operating costs</a></p> <p><a href="http://hydraulicspneumatics.com/news/parker-hannifin-announces-new-leadership">Parker Hannifin Announces New Leadership</a></p> </div> <p align="left">Karin Ferretti is certified by the Institute of Certified Franchise Executives (ICFE) and has worked as a franchise development team member with PIRTEK for 14 years. She will continue her role as franchise development administrator at PIRTEK USA Corporate Headquarters, also located in Rockledge. Dan has lived in Florida&rsquo;s Space Coast region for 15 years and has a background in finance, contract, and accounting services for major defense contractors including Lockheed Martin and Northrop Grumman.</p> <p align="left">Karin Ferretti adds that PIRTEK Space Coast&rsquo;s advanced team from the previous ownership will be beneficial to continuing the success of the facility. &ldquo;It&rsquo;s an established center and the existing team is phenomenal,&rdquo; she says. Dan describes the facility&rsquo;s potential as &ldquo;unlimited,&rdquo; and mentioned plans to increase its exposure and to raise its visibility.</p> <p align="left">Growing up in Long Island, Dan Ferretti worked for his father&rsquo;s electrical business and had aspirations to own his own business as a teen. &ldquo;I&rsquo;ve always had the desire to lead my own group of employees and to go out, do something and make a difference,&rdquo; he says. &ldquo;I believe this is that opportunity.&rdquo;</p> <p align="left">There are 57 PIRTEK Service &amp; Supply Centers and a fleet of Mobile Service Vehicles throughout the United States. Globally, PIRTEK has more than 400 locations and maintains a fleet of 2,000 Mobile Service Vehicles in 23 countries around the world.&nbsp;</p> </div> http://hydraulicspneumatics.com/news/spousal-team-takes-ownership-pirtek-space-coast-center#comments Hydraulic Filters News Wed, 13 Jul 2016 14:59:00 +0000 39211 at http://hydraulicspneumatics.com How To Store Hydraulic Cylinders -- Safely http://hydraulicspneumatics.com/blog/how-store-hydraulic-cylinders-safely <div class="node-body blog-body"><p>A question I get asked a lot by equipment owners, is the procedure for storing spare hydraulic cylinders for an extended period. So here&#39;s what I recommend:</p> <ul> <li>Always store fully retracted.</li> <li>Store indoors in a clean, dry area.</li> <li>Smear the internal surfaces of eye/clevis bushes or bearings with grease - particularly if they&#39;re steel.</li> <li>Protect any exposed chrome on the rod. Petroleum jelly-impregnated tape such as&nbsp;&nbsp; Denso tape can be used for this purpose. Before applying, make sure the rod is fully retracted. N.B. if a product like Denso tape is applied to the rod when the rod is not fully retracted, subsequent retraction of the rod can result in damage to the rod seal.</li> <li>Plug the service ports with steel - not plastic, plugs or blanking plates.</li> <li>Consider filling the cylinder with clean hydraulic oil through its rod-end service port. Particularly if it is an expensive, large diameter or high pressure cylinder. I say &quot;consider&quot; because there are a few issues to understand before you do this.</li> </ul> <p>If the cylinder is not filled with oil it will obviously be filled with air. If this air is not perfectly dry, then as ambient temperature decreases the air can reach due point. This results in moisture forming on the inside of the cylinder tube. This can cause spot rusting and pitting of the tube surface. And this will reduce the volumetric efficiency of the cylinder, the service life of the piston seal, and ultimately, the life of the tube itself.<br /> <br /> Completely filling the cylinder with clean hydraulic oil prevents this from occurring, however there&#39;s a major caution with doing this. It&#39;s best illustrated by an example:<br /> <br /> Say a cylinder is prepared for storage during the winter months. When the cylinder is filled with oil, the ambient temperature is 10 degrees Celsius. A year and a half later, during the middle of summer, the same cylinder is set down beside the machine to which it is to be installed. In the heat of the midday sun the temperature of the cylinder rises to 40 degrees Celsius. Assuming an infinitely stiff cylinder, the pressure of the oil in the cylinder resulting from the rise in temperature can be approximated by the formula:<br /> <br /> P (bar) = 11.8 x (T2 - T1)<br /> <br /> So the theoretical pressure of the oil in the cylinder is now: 11.8 x (40 - 10) = 354 bar or 5134 PSI! When it comes time for the unsuspecting mechanic to crack loose the blanks on the cylinder&#39;s service ports ... well let&#39;s just say that&#39;s more excitement that he signed up for.<br /> <br /> That said, cylinders CAN be safely filled with oil for storage provided you:</p> <ul> <li>Check that the worst-case temperature rise in storage won&#39;t result in a static pressure that exceeds the cylinder&#39;s working pressure.</li> <li>Only fill the cylinder when fully retracted and ONLY through the rod-end port. This avoids potentially dangerous pressure intensification.</li> <li>Use service port plugs or blanks that are rated for the cylinder&#39;s working pressure.</li> <li>Attach appropriate warning tags to BOTH service ports.</li> <li>Provide a means to check and vent any pressure before each of the service port blanks is removed. A simple way to do this is to fit each port blank with a pressure test-point. This enables the quick attachment of a pressure gauge to check the pressure in the cylinder. And if necessary, the pressure can be safely vented into a drum using a test-gauge hose.</li> </ul> <p>As you can see, this procedure is somewhat involved and so the decision to fill a hydraulic cylinder with oil is something you have to weigh up based on the value of the cylinder and how long you expect it to be in storage. But the bottom line is, not properly preparing spare hydraulic cylinders for long term storage can be a costly mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=smr"><strong>get &quot;Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!&quot; available for FREE download here</strong></a>.</p> </div> http://hydraulicspneumatics.com/blog/how-store-hydraulic-cylinders-safely#comments Hydraulics At Work Mon, 11 Jul 2016 23:35:00 +0000 39201 at http://hydraulicspneumatics.com Principios Ingenieriles Básicos: Transmisiones Hidrostáticas http://hydraulicspneumatics.com/blog/principios-ingenieriles-b-sicos-transmisiones-hidrost-ticas <div class="node-body blog-body"><p class="rtejustify">El principio operativo de las transmisiones hidrost&aacute;ticas es sencillo: una bomba de circuito cerrado conectada al accionamiento principal genera un caudal para accionar a su vez a un motor hidr&aacute;ulico que est&aacute; conectado a la carga. Si el desplazamiento de la bomba y el motor es fijo, la transmisi&oacute;n simplemente act&uacute;a como una caja mec&aacute;nica convencional, transmitiendo la energ&iacute;a entre el accionamiento principal y la carga. La mayor&iacute;a de &eacute;stas transmisiones, sin embargo, utilizan bombas y motores de desplazamiento variable, de manera que tanto la velocidad, el torque o la potencia puedan ser regulados (Fig. 1).<img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/Figure-1.jpg" style="font-size: 0.8em; line-height: 20px; width: 595px; height: 446px; margin: 10px;" title="Figura 1 – Las transmisiones hidrostáticas entregan gran potencia en empaque pequeño y permiten un control versátil de la máquina. El compactador que se muestra en la foto utiliza un sistema dual: uno para rotar el tambor y otro para accionar el excéntrico, el cual aumenta la fuerza de compactación por 22 kN en adición al peso de la máquina." /></p> <p class="rtejustify">Dependiendo de la configuraci&oacute;n, la transmisi&oacute;n hidrost&aacute;tica puede accionar una carga desde velocidad m&aacute;xima en una direcci&oacute;n, a la misma en la otra direcci&oacute;n, con variaci&oacute;n infinita entre ambos m&aacute;ximos &ndash; todo esto con el accionamiento principal operando a velocidad &oacute;ptima.</p> <p class="rtejustify">Las transmisiones hidrost&aacute;ticas ofrecen muchos beneficios en comparaci&oacute;n con otras formas de transmisi&oacute;n de energ&iacute;a. Dependiendo de su configuraci&oacute;n:</p> <ul> <li class="rtejustify">Relaci&oacute;n alta potencia / peso: transmite una potencia alta con un tama&ntilde;o relativamente reducido,</li> <li class="rtejustify">Baja inercia,</li> <li class="rtejustify">Operaci&oacute;n eficiente en un rango amplio de combinaciones torque-velocidad (siempre y cuando se utilicen componentes de calidad, dimensionados correctamente),</li> <li class="rtejustify">Control de velocidad en ambas direcciones independientemente de la carga, dentro de los par&aacute;metros de dise&ntilde;o,</li> <li class="rtejustify">Mantiene una velocidad predeterminada con precisi&oacute;n contra cargas de accionamiento o frenado (positivas o negativas),</li> <li class="rtejustify">Posibilidad de transmisi&oacute;n de potencia desde un accionamiento principal individual a tomas m&uacute;ltiples, incluso si la posici&oacute;n y orientaci&oacute;n de estas cambia,</li> <li class="rtejustify">Puede mantenerse detenida por sobrecarga o p&eacute;rdida de potencia sin observar da&ntilde;os,</li> <li class="rtejustify">No cede al movimiento a cero velocidad &ndash; permite igualmente un frenado din&aacute;mico,</li> <li class="rtejustify">Proporciona una respuesta m&aacute;s r&aacute;pida que las transmisiones mec&aacute;nicas o electromec&aacute;nicas de tama&ntilde;o comparable.</li> </ul> <p class="rtejustify">Las transmisiones hidrost&aacute;ticas pueden ser de dos configuraciones: integradas (bomba &ndash; motor integrados), o no integradas. La segunda es la m&aacute;s com&uacute;n en gran medida, ya que la potencia puede ser transmitida a una o m&aacute;s cargas en &aacute;reas de dif&iacute;cil acceso.&nbsp; En esta configuraci&oacute;n la bomba de acopla al accionamiento principal y el motor a&nbsp; la carga. La bomba y motor se conectan a trav&eacute;s de mangueras o tuber&iacute;a como se muestra en la Fig. 2.</p> <p><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/Figure-2-color.jpg" style="width: 595px; height: 409px; margin: 10px;" title="Figura 2 – La transmisión hidrostática en la foto consiste en una bomba de desplazamiento variable y un motor de desplazamiento fijo conectado a través de tuberías o mangueras." /></p> <p class="rtejustify">Cualquiera que sea la tarea, la transmisi&oacute;n&nbsp; debe ser dise&ntilde;ada para que exista una combinaci&oacute;n &oacute;ptima entre el motor y la carga. Esto permite que aqu&eacute;l opere a velocidad &oacute;ptima y que la transmisi&oacute;n se ajuste a las condiciones de operaci&oacute;n. Mientras mejor sea la combinaci&oacute;n entre las caracter&iacute;sticas de entrada y salida, mayor ser&aacute; la eficiencia del sistema.</p> <p class="rtejustify">A la final, el sistema de potencia debe ser dise&ntilde;ado para que exista un balance entre la eficiencia y productividad. Una m&aacute;quina dise&ntilde;ada para m&aacute;xima eficiencia generalmente tiene una respuesta poco din&aacute;mica, lo cual reduce la productividad. Por otro lado, si la m&aacute;quina se dise&ntilde;a para tener respuesta r&aacute;pida, generalmente se sacrifica eficiencia debido a que gran cantidad de energ&iacute;a debe estar disponible para hacer el trabajo &ndash; incluso cuando no existe necesidad de hacerlo.</p> <p class="rtejustify"><strong>Combinaciones</strong></p> <p class="rtejustify">La configuraci&oacute;n de una transmisi&oacute;n hidrost&aacute;tica &ndash; si tiene bomba y/o motores fijos o variables &ndash; determina sus caracter&iacute;sticas de desempe&ntilde;o. La Figura 3 resume estas configuraciones y las caracter&iacute;sticas de cada una.</p> <p class="rtejustify">La configuraci&oacute;n m&aacute;s sencilla consiste en el uso de una bomba de desplazamiento fijo accionando un motor tambi&eacute;n de desplazamiento fijo (Fig. 3a). A pesar de que este tipo de transmisi&oacute;n es relativamente de bajo costo, sus aplicaciones son limitadas, principalmente porque existen opciones alternativas que cumplen con la misma funci&oacute;n y que son m&aacute;s eficientes. Como el caudal de la bomba es fijo, la misma debe ser dimensionada para accionar al motor bajo carga m&aacute;xima. Cuando no se requiera la velocidad m&aacute;xima, el fluido de la bomba pasa por una v&aacute;lvula reguladora de presi&oacute;n, lo que genera una p&eacute;rdida que se manifiesta en calor.</p> <p class="rtejustify">Al utilizar una bomba de desplazamiento variable creamos lo que se llama una transmisi&oacute;n de torque constante (Fig. 3b). El torque es constante a toda velocidad ya que el mismo viene dado por la presi&oacute;n del sistema y desplazamiento del motor. Aumentar o disminuir el desplazamiento de la bomba aumenta o disminuye la velocidad del motor, mientras que el torque se mantiene relativamente constante.&nbsp; La potencia, por ende, aumenta al incrementar el desplazamiento de la bomba.</p> <p><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/3.gif" style="width: 595px; height: 613px; margin: 10px;" title="Figura 3 – Distintos arreglos de transmisiones hidrostáticas resumidas de acuerdo al tipo de bombas y motores utilizados. Fig. a – Bomba y motor de desplazamiento fijo; Fig. b – Bomba de desplazamiento variable, motor de desplazamiento fijo; Fig. c – Bomba de desplazamiento fijo, motor de desplazamiento variable; Fig. d – Bomba y motor de desplazamiento variable." /></p> <p class="rtejustify">Al utilizar, por otro lado, un motor de desplazamiento variable con una bomba de desplazamiento fijo, se crea una transmisi&oacute;n de potencia constante (Fig. 3c). Si el flujo al motor es constante, y el desplazamiento del motor es variado para mantener el producto de velocidad y torque (presi&oacute;n por caudal), entonces la potencia entregada es constante. Reducir el desplazamiento del motor aumente su velovidad, pero reduce el torque, nuevamente una combinaci&oacute;n de potencia constante.</p> <p class="rtejustify">La transmisi&oacute;n hidrost&aacute;tica m&aacute;s vers&aacute;til incluye tanto una bomba como motor de desplazamiento variable (Fig. 3d). En teor&iacute;a, este arreglo permite combinaciones infinitas de torque y velocidad sobre potencia. Cuando se mantiene el motor al m&aacute;ximo desplazamiento, variaciones en el caudal entregado por la bomba generan cambios en la velocidad el motor y potencia, mientras que el torque se mantiene constante. Reducir el desplazamiento del motor mientras se mantiene la bomba al m&aacute;ximo, aumenta su velocidad al m&aacute;ximo; el torque es inversamente proporcional a la velocidad, y la potencia se mantiene constante.</p> <p class="rtejustify">Las curvas en la Fig. 3d muestran dos rangos de ajuste. En el Rango 1, el desplazamiento del motor se ajusta al m&aacute;ximo; el de la bomba cambia de cero al m&aacute;ximo. El torque se mantiene constante a medida que el desplazamiento de la bomba aumenta, pero la potencia y velocidad aumentan tambi&eacute;n.</p> <p class="rtejustify">El Rango 2 comienza cuando la bomba alcanza su desplazamiento m&aacute;ximo, el cual se mantiene mientras el desplazamiento del motor se reduce. En este rango el torque se reduce a medida que la velocidad incrementa, pero la potencia se mantiene constante (en teor&iacute;a, la velocidad del motor puede incrementar infinitamente, pero en la pr&aacute;ctica obviamente se limita por din&aacute;mica.)</p> <p class="rtejustify"><strong>Ejemplo de Aplicaci&oacute;n</strong></p> <p class="rtejustify">Asuma que una carga de 3,116 lb in deba ser accionada a 1,000 rpm con una transmisi&oacute;n de desplazamiento fijo. La potencia requerida viene dada por:</p> <p class="rtejustify"><em>P</em>&nbsp;=&nbsp;<em>T</em>&nbsp;&times;&nbsp;<em>N</em>&nbsp;/ 63,024</p> <p class="rtejustify">Donde:</p> <p class="rtejustify"><em>P</em>&nbsp;es la potencia en hp</p> <p class="rtejustify"><em>T</em>&nbsp;es el torque en lb-in., y</p> <p class="rtejustify"><em>N</em>&nbsp;es la velocidad en rpm.</p> <p class="rtejustify">Por lo tanto:</p> <p class="rtejustify"><em>P</em>&nbsp;= 3,116 &times; 1,000 / 63,024 = 50 hp</p> <p class="rtejustify">Si seleccionamos una bomba de 2,000 psi (basado en experiencia para obtener una buena combinaci&oacute;n de tama&ntilde;o, peso, desempe&ntilde;o y costo) rateada en 50 hp, calculamos entonces el caudal que debe entregar:</p> <p class="rtejustify"><em>q</em>&nbsp;= 1,714 &times;&nbsp;<em>P</em>&nbsp;/&nbsp;<em>p</em></p> <p class="rtejustify">Donde:</p> <p class="rtejustify"><em>q</em>&nbsp;es el caudal en gpm, y</p> <p class="rtejustify"><em>p</em>&nbsp;es la presi&oacute;n en psi.</p> <p class="rtejustify">Por lo tanto,</p> <p class="rtejustify"><em>q</em>&nbsp;= 1,714 &times; 50 / 2,000 = 43 gpm (despreciando consideraciones de eficiencias para simplificar la selecci&oacute;n)</p> <p class="rtejustify">Podemos entonces seleccionar un motor con un desplazamiento de 10 pulgadas c&uacute;bicas por revoluci&oacute;n, que entrega 3,116 lb-in de torque a 2,000 psi y gira a aproximadamente 1,000 con un caudal de 43 gpm. La Figura 3a muestra las caracter&iacute;sticas de potencia, torque y velocidad para el conjunto bomba motor, asumiendo que la bomba opera a velocidad constante.</p> <p class="rtejustify">El caudal de la bomba es m&aacute;ximo a esta velocidad operativa, y la misma entrega este caudal al motor de desplazamiento fijo. La inercia hace imposible una aceleraci&oacute;n instant&aacute;nea a m&aacute;xima velocidad, por lo que parte del flujo pasa por la reguladora de presi&oacute;n (la Figura 3&ordf; tambi&eacute;n muestra la p&eacute;rdida de potencia durante la aceleraci&oacute;n). A medida que la velocidad del motor aumenta, transmite m&aacute;s caudal de la bomba y menos aceite fluye a trav&eacute;s de la reguladora de presi&oacute;n. A la velocidad de dise&ntilde;o, (casi) todo el aceite pasa por el motor.</p> <p class="rtejustify">El torque es constante porque la presi&oacute;n del sistema aumenta hasta el punto de ajuste de la v&aacute;lvula reguladora inmediatamente al accionar la v&aacute;lvula. La potencia perdida por la reguladora es la diferencia entre la potencia constante entregada por la bomba y la variable entregada por el motor.<img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/4.gif" style="width: 300px; height: 285px; margin: 10px; float: left;" title="Figura 4 – Velocidad crítica (indicada en el punto A) en una transmisión hidrostática de potencia constante, es la velocidad mínima a la cual se puede transferir la máxima potencia." />El &aacute;rea bajo la curva representa la p&eacute;rdida de potencia cuando la transmisi&oacute;n arranca o para. Tambi&eacute;n muestra la baja eficiencia para cualquier velocidad por debajo de la m&aacute;xima. Una transmisi&oacute;n de desplazamiento fijo no se recomienda para aplicaciones que requieran de paradas constantes o cuando se requiera menos de la m&aacute;xima capacidad con frecuencia.</p> <p class="rtejustify"><strong>Relaci&oacute;n Torque &ndash; Velocidad</strong></p> <p class="rtejustify">En teor&iacute;a, la potencia m&aacute;xima que una trasmisi&oacute;n hidrost&aacute;tica puede transmitir es funci&oacute;n del caudal y la presi&oacute;n. Sin embargo, en transmisiones de potencia constante con velocidades de salida variables, la potencia te&oacute;rica dividida por la relaci&oacute;n torque / velocidad, determina la potencia real de salida. La potencia m&aacute;xima constante que puede ser transmitida es determinada por la velocidad m&iacute;nima a la cual esta potencia puede ser transmitida.</p> <p class="rtejustify">Por ejemplo, si la velocidad m&iacute;nima dada por el punto A en la curva de potencia de la Figura 4 es la mitad de la velocidad m&aacute;xima, la relaci&oacute;n torque &ndash; velocidad es 2:1. La potencia m&aacute;xima que puede ser transmitida es la mitad de la m&aacute;xima te&oacute;rica. El punto B, que corresponde a velocidad de salida A, la curva de torque disminuye a medida que la velocidad incrementa. A velocidad m&aacute;xima cae al punto C.</p> <p class="rtejustify">A velocidades por debajo de la mitad de la m&aacute;xima, el torque se mantiene constante al m&aacute;ximo nivel, pero la potencia disminuye proporcionalmente con la velocidad. La velocidad en el punto A es la <em>velocidad cr&iacute;tica</em> y es determinada por la din&aacute;mica de los componentes de la transmisi&oacute;n. Por debajo de la velocidad cr&iacute;tica, la potencia disminuye linealmente (a torque constante) a cero, a cero rpm. Por encima de la velocidad cr&iacute;tica, el torque disminuye a medida que aumenta la velocidad, lo que proporciona una potencia constante.</p> <p class="rtejustify"><strong>Construcci&oacute;n de una Transmisi&oacute;n Hidrost&aacute;tica de Circuito Cerrado</strong></p> <p class="rtejustify">Las descripciones de las transmisiones hidrost&aacute;ticas mostradas en la Fig. 3 se concentran &uacute;nicamente en las consideraciones param&eacute;tricas del sistema. Funciones adicionales deben ser consideradas para lograr un funcionamiento pr&aacute;ctico de la transmisi&oacute;n en cuesti&oacute;n.</p> <p class="rtejustify"><strong>Componentes del lado de la bomba: </strong>consideremos el caso de una transmisi&oacute;n de torque constante &ndash; la m&aacute;s com&uacute;nmente utilizada &ndash; con una bomba de desplazamiento variable accionando a uno motor de desplazamiento fijo (Fig. 5a). Debido a que es una transmisi&oacute;n de circuito cerrado, fuga interna se acumula en las carcasas de la bomba y motor(es) y es removido a trav&eacute;s de una l&iacute;nea de fuga (Fig. 5b). El flujo combinado se dirige al reservorio pasando por un intercambiador de calor.</p> <p class="rtejustify">Uno de los componentes m&aacute;s importantes en una transmisi&oacute;n hidrost&aacute;tica es la bomba de precarga. La misma generalmente es parte integral de la bomba principal, pero existen configuraciones en las que se encuentra montada de manera independiente. Cualquiera que sea el arreglo, esta bomba cumple dos funciones: previene cavitaci&oacute;n en la bomba principal al proveer a la misma del caudal perdido por fuga interna, por otro lado proporciona aceite presurizado necesario para el control del desplazamiento de aquella.</p> <p class="rtejustify">Si observamos la Fig. 5c, la v&aacute;lvula limitadora de presi&oacute;n baja A ubicada del lado de descarga de la bomba de precarga, ajusta la presi&oacute;n de control. A pesar de que las presiones var&iacute;an de fabricante en fabricante, generalmente rondan entre los 250 y 300 psi. Las v&aacute;lvulas antirretorno B y C proveen de flujo complementario seg&uacute;n se requiera a las l&iacute;neas a baja presi&oacute;n.</p> <p class="rtejustify"><strong>Componentes del lado del motor: </strong>los circuitos t&iacute;picos de transmisiones hidrost&aacute;ticas requieren el uso de v&aacute;lvulas reguladoras de presi&oacute;n tipo <em>crossover</em> (ver v&aacute;lvulas D y E en la Figura 5d). Estas generalmente vienen incluidas en el motor y se instalan para prevenir que se generen picos de presi&oacute;n en las l&iacute;neas de suministro como resultado de interrupci&oacute;n o cambios en el flujo, cargas de impacto o fuera de control, entre otras condiciones. La presi&oacute;n es limitada enviando flujo a alta presi&oacute;n al lado a baja presi&oacute;n de manera similar que en circuitos abiertos. Sin embargo, se ubican cerca del motor ya que es ah&iacute; donde se originan los picos de presi&oacute;n.</p> <p class="rtejustify">Adem&aacute;s de las v&aacute;lvulas limitadoras de presi&oacute;n, se incluye una v&aacute;lvula selectora o <em>Shuttle</em>, la cual es siempre accionada por fluido a alta presi&oacute;n y conecta el lado de baja con una v&aacute;lvula limitadora de presi&oacute;n de baja G. Esta v&aacute;lvula conduce el exceso de flujo de precarga a la carcasa del motor, a trav&eacute;s de la l&iacute;nea de drenaje, a la carcasa de la bomba. El mismo luego retorna al reservorio a trav&eacute;s del intercambiador de calor.</p> <p class="rtejustify"><strong>Control de Cavitaci&oacute;n</strong></p> <p class="rtejustify">Lo din&aacute;mico de una transmisi&oacute;n hidrost&aacute;tica depende de la compresibilidad del fluido y la firmeza de los componentes utilizados, espec&iacute;ficamente de las tuber&iacute;as y mangueras. Estos tienen una influencia similar a la de un acumulador de resorte conectado a la l&iacute;nea. Bajo cargas livianas, el efecto acumulador es leve, mientras que bajo cargas pesadas existe una mayor compresi&oacute;n, lo que conlleva la necesidad de complementar este volumen adicional de fluido requerido, funci&oacute;n que igualmente cumple la bomba de precarga.</p> <p class="rtejustify"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/5.gif" style="width: 595px; height: 469px; margin: 10px;" title="Figura 5 – Se muestra la progresión de circuitos de transmisiones hidrostáticas de potencia constante; desde una bomba y motor sencillos hasta un ensamblaje con accesorios varios." /></p> <p class="rtejustify">El factor cr&iacute;tico es la tasa de aumento de presi&oacute;n en el sistema. Si la misma aumenta bruscamente, la tasa de aumento de volumen en el lado de suministro (flujo de compresibilidad) puede exceder la capacidad de la bomba de precarga, lo que puede resultar en cavitaci&oacute;n en la bomba principal. Quiz&aacute;s los circuitos con bombas de desplazamiento variable con controles autom&aacute;ticos tienen el mayor riesgo. Cuando ocurre cavitaci&oacute;n en este tipo de sistemas, la presi&oacute;n cae o desaparece; el control intenta responder, lo que resulta en inestabilidad en el sistema.</p> <p class="rtejustify">Matem&aacute;ticamente la tasa de aumento de presi&oacute;n viene dada por:</p> <p class="rtejustify"><em>dp</em>/<em>dt</em>&nbsp; =<em>&nbsp;B<sub>e</sub>&nbsp;Q<sub>cp</sub></em>/<em>&nbsp;V</em></p> <p class="rtejustify">Donde:</p> <p class="rtejustify">B<em><sub>e</sub></em>&nbsp;es el m&oacute;dulo de compresibilidad del sistema en psi,</p> <p class="rtejustify"><em>V</em>&nbsp;es el volumen de fluido en el lado de presi&oacute;n, expresado en in.3, y</p> <p class="rtejustify"><em>Q<sub>cp</sub></em>&nbsp;es el caudal de la bomba de precarga en in.<sup>3</sup>/sec.</p> <p class="rtejustify"><strong>Otro Ejemplo de Aplicaci&oacute;n</strong></p> <p class="rtejustify">Asumamos que la transmisi&oacute;n de la Figura 5 est&aacute; conectada a 2 ft de tuber&iacute;a de 1 &frac12;&rdquo; de di&aacute;metro. Despreciando los vol&uacute;menes de la bomba y el motor, tenemos que ser&iacute;a de aproximadamente 30 pulgadas c&uacute;bicas. Para aceite en tuber&iacute;as de acero, el m&oacute;dulo de compresibilidad es de aproximadamente 200,000 psi. Si asumimos que la bomba de precarga entrega 6 gpm (29 pulgadas c&uacute;bidas / seg), entonces la tasa de aumento de presi&oacute;n ser&iacute;a:</p> <p class="rtejustify"><em>dp</em>/<em>dt</em>&nbsp; = 200,000 &times; 28 / 30</p> <p class="rtejustify">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 187,000 psi/seg.</p> <p class="rtejustify">Ahora consideremos el efecto de conectar el sistema con 20 pies de manguera de 1 &frac12;&rdquo; de di&aacute;metro, costura triple. El fabricante de la manguera tendr&iacute;a que facilitar el coeficiente de expansi&oacute;n en pulgadas c&uacute;bicas por 1,000 psi para calcular el m&oacute;dulo de compresibilidad. Asumamos para este caso que es de 84,000 psi.</p> <p class="rtejustify">Entonces:</p> <p class="rtejustify"><em>dp</em>/<em>dt</em>&nbsp; = 84,000 &times; 28 / 294.5 = 7,986 psi/seg</p> <p class="rtejustify">Aumentar la salida de la bomba de precarga ser&iacute;a la manera m&aacute;s efectiva de prevenir la tendencia de cavitaci&oacute;n del sistema. Como alternativa, si los cambios en la carga no son continuos, se puede agregar un acumulador al circuito de precarga. De hecho, algunos fabricantes proveen un p&oacute;rtico para conectar el acumulador.</p> <p class="rtejustify">Si la din&aacute;mica del sistema es baja y el mismo est&aacute; equipado con controles autom&aacute;ticos, la transmisi&oacute;n deber&aacute; ser arrancada con la bomba en desplazamiento en cero. Adem&aacute;s la aceleraci&oacute;n del sistema deber&aacute; ser controlada para evitar arranques bruscos que pudiesen generar picos de presi&oacute;n indeseados. Algunos fabricantes proveen orificios de amortiguaci&oacute;n en el servo para prevenir que esto pase.</p> <p class="rtejustify">Toda esta discusi&oacute;n muestra lo multifac&eacute;tico de la funci&oacute;n de la bomba de precarga en una transmisi&oacute;n hidrost&aacute;tica circuito cerrado. Como vemos, la din&aacute;mica del sistema y el control de la tasa de aumento de presi&oacute;n probablemente son las consideraciones principales al dimensionar esta bomba.</p> <p class="rtejustify">&nbsp;</p> <p><em>Ricardo Sol&oacute;rzano&nbsp;trabaja en EEM Technologies Corp., un distribuidor integral de soluciones en t&eacute;cnica de fluidos para el mercado Latino Americano. Para mayor informaci&oacute;n, favor contactarlo al +1(855)462-7633, <a href="mailto:info@eemtechnologies.com">info@eemtechnologies.com</a>, <a href="http://www.eemtechnologies.com">www.eemtechnologies.com</a>.</em></p> <p class="rtejustify">&nbsp;</p> </div> http://hydraulicspneumatics.com/blog/principios-ingenieriles-b-sicos-transmisiones-hidrost-ticas#comments Hydraulic Pumps & Motors H&amp;P en tu idioma! Mon, 11 Jul 2016 16:06:00 +0000 39181 at http://hydraulicspneumatics.com July 2016 http://hydraulicspneumatics.com/hydraulics-pneumatics/2016-07-11 <div class="node-body magazine_issue-body"></div> <fieldset class="fieldgroup group-mag-teasers"> <div class="field-mag-teaser"> <a href="/hydraulic-filters/filtration-advice-experts">Filtration Advice from the Experts</a> <a href="/hose-tubing/smaller-hose-produces-long-list-benefits">Smaller Hose Produces Long List of Benefits</a> <a href="/cylinders-actuators/sensor-choices-pneumatic-cylinder-positioning">Sensor Choices for Pneumatic Cylinder Positioning</a> </div> </fieldset> <fieldset class="fieldgroup group-publication-info"><legend>Publication Info</legend> </fieldset> Mon, 11 Jul 2016 04:00:00 +0000 39351 at http://hydraulicspneumatics.com Engineering Essentials: Hydrostatic Transmissions http://hydraulicspneumatics.com/200/TechZone/HydraulicPumpsM/Article/False/6450/TechZone-HydraulicPumpsM <div class="field-deck"> Hydrostatic transmissions (HSTs) boast a long list of characteristics that make them the first choice for countless applications. </div> <div class="node-body article-body"><table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/hydrostatic-transmissions-pdf-download">Download this article in .PDF format</a><br /> This file type includes high resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> <p>The operating principle of hydrostatic transmissions (HSTs) is simple: A pump, connected to the prime mover, generates flow to drive a hydraulic motor, which is connected to the load. If the displacement of the pump and motor are fixed, the HST simply acts as a gearbox to transmit power from the prime mover to the load. Most HSTs, however, use a variable-displacement pump, motor, or both so that speed, torque, or power can be regulated <em>(Fig. 1)</em>.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-amp-motors/hydrostatic-transmissions-power-play-wind-turbine-design">Hydrostatic Transmissions: A Power Play in Wind Turbine Design</a></p> <p><a href="http://hydraulicspneumatics.com/200/TechZone/HydraulicPumpsM/Article/False/11799/TechZone-HydraulicPumpsM">Hydrostatic Transmissions are Evolving</a></p> <p><a href="http://hydraulicspneumatics.com/200/TechZone/HydraulicPumpsM/Article/False/86140/TechZone-HydraulicPumpsM">Understanding Hydrostatic Transmissions</a></p> </div> <p>Depending on its configuration, the HST can drive a load from full speed in one direction to full speed in the opposite direction, with infinite variation of speed between the two maximums&mdash;all with the prime mover operating at its optimum speed.</p> <p><img alt="Fig. 1" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/Figure-1.jpg" style="width: 595px; height: 446px;" title="1. Hydrostatic drives pack a lot of power into a small package and allow versatile machine control. The walk-behind compactor shown here uses a dual hydrostatic drive: one to rotate the drum, and one to rotate an eccentric weight, which increases compacting force by nearly 22 kN in addition to the machine’s weight." /></p> <p>HSTs offer many important advantages over other forms of power transmission. Depending on its configuration, an HST:</p> <ul> <li>transmits high power in a compact size</li> <li>exhibits low inertia</li> <li>operates efficiently over a wide range of torque-to-speed ratios</li> <li>maintains controlled speed (even in reverse) regardless of load, within design limits</li> <li>maintains a preset speed accurately against driving or braking loads</li> <li>can transmit power from a single prime mover to multiple locations, even if position and orientation of the locations changes</li> <li>can remain stalled and undamaged under full load at low power loss</li> <li>does not creep at zero speed</li> <li>provides faster response than mechanical or electromechanical transmissions of comparable rating, and</li> <li>can provide dynamic braking.</li> </ul> <p>Either of two types of construction is used for HSTs: integral and non-integral. Non-integral construction is by far the most common, because power can be transmitted to one or more loads in areas that would otherwise be difficult to access. In this technique, the pump is coupled to the prime mover, the motor is coupled to the load, and they the pump and motor are connected through hose and tubing assemblies, <em>Fig. 2</em>.</p> <p><img alt="Fig. 2" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/Figure-2-color.jpg" style="width: 595px; height: 409px;" title="2. This closed hydrostatic transmission consists of a variable-displacement pump and fixed-displacement motor connected through metal tubing and hose. Providing a reservoir between the pump and motor would make this an open-circuit system." /></p> <p>Whatever its task, the HST must be designed for an optimum match between the engine and the load. This allows the engine to operate at its most efficient speed and the HST to make adjustments to operating conditions. The better the match is between input and output characteristics, the more efficient the entire power system will be.</p> <p>Ultimately the power system should be designed for a balance between efficiency and productivity. A machine designed for maximum efficiency usually has sluggish response, which robs productivity. Conversely, a machine designed for quick response usually exhibits low efficiency because a high degree of energy must be available at all times to perform work&mdash;even when there is no immediate need for work.</p> <h3>Four Functional Types of HSTs</h3> <p>The configuration of an HST&mdash;whether it has a fixed- or variable displacement pump, motor, or both&mdash;determines its performance characteristics. <em>Figure 3</em> summarizes these configurations and the performance characteristics of each.</p> <p>The simplest form of hydrostatic transmission uses a fixed-displacement pump driving a fixed-displacement motor (Fig. 3a). Although this transmission is inexpensive, its applications are limited, primarily because alternative forms of power transmission are much more energy efficient. Because pump displacement is fixed, the pump must be sized to drive the motor at a fixed speed under full load. When full speed is not required, fluid from the pump outlet passes over the relief valve. This wastes energy in the form of heat.</p> <p>Using a variable-displacement pump instead of one with a fixed displacement creates a constant torque transmission (Fig. 3b). Torque output is constant at any speed because torque depends only on fluid pressure and motor displacement. Increasing or decreasing pump displacement increases or decreases motor speed, respectively, while torque remains fairly constant. Power, therefore, increases with pump displacement.</p> <p><img alt="Fig. 3" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/3.gif" style="width: 595px; height: 613px;" title="3. Functional hydrostatic transmissions summarized according to types of pumps and motors involved: Fig. a shows HST with fixed-displacement pump and motor; Fig. b has fixed motor and variable-displacement pump; Fig. c has fixed pump and variable-displacement motor, and Fig. d has a variable-displacement pump and motor. " /></p> <p>Using a variable-displacement motor with a fixed-displacement pump produces a transmission that delivers constant power (Fig. 3c). If flow to the motor is constant, and motor displacement is varied to maintain the product of speed and torque constant, then power delivered is constant. Decreasing motor displacement increases motor speed, but decreases torque&mdash;a combination that maintains constant power.</p> <p>The most versatile HST configuration teams a variable-displacement pump with a variable-displacement motor (Fig. 3d). Theoretically, this arrangement provides infinite ratios of torque and speed to power. With the motor at maximum displacement, varying pump output directly varies speed and power output while torque remains constant. Decreasing motor displacement at full pump displacement increases motor speed to its maximum; torque varies inversely with speed, and horsepower remains constant.</p> <p>The curves in Fig. 3d illustrate two ranges of adjustment. In <em>Range 1</em>, motor displacement is fixed at maximum; pump displacement increases from zero to maximum. Torque remains constant as pump displacement increases, but power and speed increase.</p> <p><em>Range 2</em> begins when the pump reaches maximum displacement, which is maintained while the motor&rsquo;s displacement decreases. Throughout this range, torque decreases as speed increases, but power remains constant. (Theoretically, motor speed could be increased infinitely, but from a practical standpoint, it is limited by dynamics.)</p> <h3>An Application Example</h3> <p>Assume that a 3,116-lb-in. torque load must be driven at 1,000 rpm with a fixed-displacement HST. Power required is determined from:</p> <p><em>P</em> = <em>T</em> &times; <em>N</em> / 63,024</p> <p>Where:</p> <p><em>P</em> is power in hp</p> <p><em>T</em> is torque in lb-in., and</p> <p><em>N</em> is speed in rpm.</p> <p>Therefore,</p> <p><em>P</em> = 3,116 &times; 1,000 / 63,024 = 50</p> <p>If we choose a 2,000-psi pump (based on experience for providing a good combination of size, weight, performance, and cost) rated at 50 hp, we then calculate the flow it must deliver:</p> <p><em>q</em> = 1,714 &times; <em>P</em> / <em>p</em></p> <p>Where:</p> <p><em>q</em> is flow in gpm, and</p> <p><em>p</em> is pressure in psi.</p> <p>Therefore,</p> <p><em>q</em> = 1,714 &times; 50 / 2,000 = 43 gpm</p> <p>We then select a hydraulic motor with a displacement of 10 in.3 /rev to deliver 3,116 lb-in. of torque at 2,000 psi&mdash;approximately 43 gpm at 1,000 rpm. Figure 3a shows the power/torque/speed characteristics for the pump and motor, assuming the pump operates at constant speed.</p> <p>Pump flow is maximum at this operating speed, and the pump attempts to deliver this quantity of oil to the fixed-displacement hydraulic motor. Load inertia makes it impossible to accelerate instantaneously to full speed, so part of the pump output flows over the relief valve. (Figure 3a also illustrates the power loss during acceleration.) As the motor increases speed, it transmits more of the pump&rsquo;s output, and less oil flows over the relief valve. At rated speed, all oil flows through the motor.</p> <p>Torque is constant because system pressure builds to the relief valve setting immediately after the control valve shifts. Power lost over the relief valve is the difference between the constant power delivered by the pump and the variable power delivered by the motor.</p> <p><img alt="Fig. 4" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/4.gif" style="width: 300px; height: 285px; margin: 5px; float: left;" title="4. Critical speed (indicated by point A) in a constant-power HST is the lowest speed at which maximum constant power can be transmitted. " />The area under this curve represents the power wasted when the transmission starts or stops. It also shows the low efficiency for any operating speed below maximum. A fixed-displacement transmission is not recommended for applications requiring frequent starts and stops, or when less than full load torque occurs frequently.</p> <h3>Torque-Speed Ratio</h3> <p>Theoretically, the maximum power a hydrostatic transmission can transmit is a function of flow and pressure. However, in constant power transmissions with variable output speeds, theoretical power divided by the torque/speed ratio determines actual power output. The greatest constant power that can be transmitted is determined by the lowest output speed at which this constant power must be transmitted.</p> <p>For example, if the minimum speed represented by point A on the power curve in <em>Fig. 4</em> is half the maximum speed, the torque-to-speed ratio is 2:1. The maximum power that can be transmitted is half the theoretical maximum. At point B, corresponding to output speed A, the torque curve decreases as speed increases. At maximum output speed, it has dropped to point C.</p> <p>At output speeds less than half the maximum, torque remains constant at its maximum value, but power decreases in proportion to speed. The speed at point A is the <em>critical speed</em> and is determined by the dynamics of the HST&rsquo;s components. Below critical speed, power decreases linearly (with constant torque) to zero at zero rpm. Above critical speed, torque decreases as speed increases, which provides constant power.</p> <h3>Building a Closed-circuit HST</h3> <p>The descriptions of closed-circuit hydrostatic transmissions in Fig. 3 concentrate on parametric considerations only. Additional functions must be provided to achieve a practical HST.</p> <p><strong>Pump-end components.</strong> Consider, for example, a constant-torque HST&mdash;the type used most commonly&mdash;with a servo-controlled, variable-displacement pump driving a fixed-displacement motor <em>(Fig. 5a)</em>. Because this is a closed-circuit HST, slip flow accumulates in the pump and motor cases and is removed through a case drain line (Fig. 5b). The combined case drains flow to the reservoir through a heat exchanger.</p> <p>One of the most important components in a closed-circuit HST is a charge pump. The charge pump is usually an integral part of the main pump package, but can also be an independent pump gang-mounted with the drive pumps it serves. Whatever the arrangement, the charge pump performs two functions. First, it prevents cavitation of the main pump by replenishing the fluid lost by the closed system through pump and motor slip. It also provides pressurized fluid required by the variable-displacement control mechanism.</p> <p>Referring now to Fig. 5c, low-pressure relief valve <em>A</em> on the discharge side of the charge pump sets control pressure. Although charge pressures vary from one pump manufacturer to another, they typically range between 250 and 300 psi. Back-to-back replenishing check valves <em>B</em> and <em>C</em> supply make-up fluid to the appropriate low-pressure line.</p> <p><strong>Motor-end components.</strong> A typical, closed-circuit HST also requires crossover relief valves <em>D</em> and <em>E</em> (Fig. 5d). These usually are integrated into the motor package. Two crossover relief valves are installed to prevent excessive pressure from developing in either supply line due to shock-load feedback through the motor, an overrunning load, or similar conditions. These valves limit pressure in either pressure supply line by routing high-pressure fluid to the low-pressure line. These relief valves perform the same function as a system relief valve in an open circuit. However, they are located at the fluid motor end because this is where overpressures originate in closed-circuit HSTs.</p> <p>In addition to crossover relief valves, shuttle valve <em>F</em> is included. The shuttle valve is always shifted by high-pressure fluid, which connects the low-pressure line to low-pressure relief valve <em>G</em>.&nbsp; Valve <em>G</em> routes excess charge pump flow to the motor case, then through the drain line to the pump case. Fluid then returns to the charge pump reservoir through the heat exchanger.</p> <h3>Cavitation Control</h3> <p>The stiffness of an HST depends on the compressibility of the fluid and the compliance of system components&mdash;namely, tubing and hoses. The influence of these components can be compared to the effect a spring-loaded accumulator would have if connected to the supply line through a tee fitting. Under light loads, the effective accumulator spring compresses slightly; under heavy loads, the accumulator undergoes substantial compression, and there is more fluid in the accumulator. This additional fluid volume must be supplied by the charge pump.</p> <p><img alt="Fig. 5" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/07/08/5.gif" style="width: 595px; height: 469px;" title="5. Displayed is the progression of constant-power HST circuits, from a bare pump and motor to an assembly with basic accessories. " /></p> <p>The critical factor is the rate of pressure rise in the system. If pressure rises too rapidly, the rate of volume increase on the supply side (compressibility flow) may exceed the flow capacity of the charge pump, and the main pump may cavitate. Perhaps circuits powered by variable-displacement pumps with automatic controls pose the most serious threat of danger. When such a system cavitates, pressure drops or disappears altogether. The automatic controls can attempt to respond, resulting in an unstable system.</p> <p>Mathematically, the rate of pressure rise can be expressed as:</p> <p><em>dp</em>/<em>dt</em>&nbsp; =<em> B<sub>e</sub> Q<sub>cp</sub></em>/<em> V</em></p> <p>Where:</p> <p>B<em><sub>e</sub></em> is effective bulk modulus of the system, psi</p> <p><em>V</em> is volume of fluid on pressure side in in.3, and</p> <p><em>Q<sub>cp</sub></em> is charge pump output in in.<sup>3</sup>/sec.</p> <h3>Another Application Example</h3> <p>Assume that the HST of Fig. 5 is connected with 2 ft of 1&frac12;-in. ID steel tubing. Neglecting the volumes of pump and motor, V is about 30 in.3&nbsp; For oil in steel tubing, effective bulk modulus is roughly 200,000 psi. Assuming the charge pump delivers 6 gpm (28 in.3 /sec), then the rate of pressure rise is:</p> <p><em>dp</em>/<em>dt</em>&nbsp; = 200,000 &times; 28 / 30</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 187,000 psi/sec.</p> <p>Now consider the effect of plumbing the system with 20 ft of 1&frac12;-in. ID, three-wire braided hose. The hose manufacturer would have to provide the volumetric expansion coefficient in in.3/1,000-psi to enable calculating the effective bulk modulus. Assume, for this example, that <em>B<sub>e</sub></em> is about 84,000 psi.</p> <p>Then:</p> <p><em>dp</em>/<em>dt</em>&nbsp; = 84,000 &times; 28 / 294.5 = 7,986 psi/sec</p> <p>Increasing the output of the charge pump would be the most effective way to prevent the tendency of such a system to cavitate. Alternately, if changes in the external load are not continuous, an accumulator can be added to the charge circuit. In fact, some HST manufacturers provide a port for connecting an accumulator to the charge circuit.</p> <p>If the stiffness of the HST is low, and it is equipped with automatic controls, the HST should be started with pump displacement at zero. In addition, acceleration of the displacement mechanism should be limited to prevent jerky starts, which, in turn, could generate excessive pressure surges. Some HST manufacturers provide damping orifices in the stroking circuit for this very purpose.</p> <p>This discussion demonstrates the multi-faceted role of the charge pump system in a closed-circuit HST. Therefore, system stiffness and control of the rate of pressure rise may be the primary considerations for determining charge pump delivery, rather than simply internal leakage of the pump and motors.</p> <p><em>Looking for parts? Go to <a href="http://www.SourceESB.com" target="_blank">SourceESB</a>.</em></p> <table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/hydrostatic-transmissions-pdf-download">Download this article in .PDF format</a><br /> This file type includes high resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> </div> Hydraulics Hydraulic Pumps & Motors Fri, 08 Jul 2016 20:38:00 +0000 6525 at http://hydraulicspneumatics.com Maintenance-Free Accumulators Flying High http://hydraulicspneumatics.com/accumulators/maintenance-free-accumulators-flying-high <div class="node-body article-body"><table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/maintenance-free-accumulators-flying-high-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/CESSNA-PR-image.jpg" style="width: 595px; height: 260px;" title="Cessna’s Citation Longitude, which relies on hydraulics for essential flight control and other functions, uses maintenance-free accumulators that are rated for the life of aircraft." /></p> <p><a href="http://cessna.txtav.com/" target="_blank">Cessna</a>, now a division of <a href="http://txtav.com/" target="_blank">Textron Aviation Inc.</a>, has been synonymous with private and corporate aircraft for generations. Cessna&rsquo;s latest entry into luxurious corporate aircraft is the Citation Longitude, which holds up to 12 passengers and has a maximum range of 6,297 km, with maximum cruising speed of 882 km/hr. Featuring a wingspan of 67 ft. and length of just over 73 ft., the Longitude offers complete touchscreen control of navigation and communication systems with the next evolution of Garmin&rsquo;s G5000 flight deck.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/accumulators/metal-bellows-make-tough-accumulators-0">Metal Bellows Make Tough Accumulators</a></p> <p><a href="http://hydraulicspneumatics.com/accumulators/lighter-side-accumulators">The Lighter Side of Accumulators</a></p> <p><a href="http://hydraulicspneumatics.com/accumulators/many-roles-accumulators">he Many Roles of Accumulators</a></p> </div> <p>As with all aircraft this size and larger, the Longitude makes extensive use of hydraulics for controlling flight surfaces and many other functions. The hydraulic components and systems incorporate the most advanced technology available for compact design, light weight, and, of course, reliability.</p> <p>Like many hydraulic systems, accumulators are needed for a variety of hydraulic functions, such as storing hydraulic energy and shock and vibration control. However, piston and bladder accumulators, which are widely used throughout the hydraulics industry, prove less than ideal for aircraft. That&rsquo;s because piston seals must be replaced periodically and bladder accumulators come with their own set of limitations.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Senior-accumulators.jpg" style="width: 595px; height: 310px;" title="Welded-diaphragm metal-bellows accumulators from Senior Aerospace do not contain elastomeric seals, so they operate for years without needing to be recharged or any other maintenance. " /></p> <p>To circumvent these challenges, Textron Aviation specifies metal bellows accumulators from <a href="http://senioraerospace.com/" target="_blank">Senior Aerospace</a>, Sharon, Mass., in the Cessna Citation. These proprietary, maintenance-free accumulators hold a gas charge within a hermetically sealed, welded-diaphragm metal bellows; no elastomeric seals are used. Thanks to proprietary gas-analysis software, Senior&rsquo;s engineers were able to create an efficient design that met the Longitude&rsquo;s specification requirements.</p> <p>The Longitude represents Cessna&rsquo;s first aircraft to incorporate all-metal bellows accumulators. The accumulators on the aircraft are used in the main hydraulic system; inboard, midboard, and outboard spoilers; emergency parking brake; and nose wheel steering.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MetalBellowsAccumulator.gif" style="width: 595px; height: 345px;" /></p> <p>Technicians responsible for maintaining the Longitude will have fewer components to routinely service because Senior&rsquo;s maintenance-free accumulators are designed to last the life of the aircraft. The accumulators will never require recharging or seal replacement, as is common with conventional piston and bladder accumulators.&nbsp;</p> <p><em>For more information on Senior Aerospace&rsquo;s welded-diaphragm metal-bellows accumulators, call (888) 235-5697, or visit <a href="http://www.metalbellows.com/" target="_blank">www.metalbellows.com</a></em><em>.</em></p> <p><strong><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></strong></p> <table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/maintenance-free-accumulators-flying-high-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> </div> http://hydraulicspneumatics.com/accumulators/maintenance-free-accumulators-flying-high#comments Accumulators Aerospace Fri, 08 Jul 2016 18:03:00 +0000 39161 at http://hydraulicspneumatics.com Hydraulically Operated Machine Trims Orchard Trees http://hydraulicspneumatics.com/agricultural/hydraulically-operated-machine-trims-orchard-trees <div class="node-body article-body"><table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/machine-trims-tops-sides-orchard-trees-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> <p align="left">Orchard growers have long known that getting the maximum quantity and quality of fruit is based, in part, on the size and shape of the trees. Strategic <em>hedging</em> and <em>topping</em> exposes each tree to maximum sunlight and moisture, at the same time discouraging disease. Hedging helps maintain distances between rows so that equipment can be used in orchards without damaging the trees, whereas topping keeps trees from growing too tall to harvest.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/forestry-lumber/tree-processor-comes-full-circle-hydraulic-swivels">Tree Processor Comes Full Circle with Hydraulic Swivels</a></p> <p><a href="http://hydraulicspneumatics.com/200/TechZone/HydraulicPumpsM/Article/False/84399/TechZone-HydraulicPumpsM">Tree Trimmer Showcases Hydraulics</a></p> <p><a href="http://hydraulicspneumatics.com/applications/brush-cutter-right-track">Brush Cutter Is on the Right Track</a></p> </div> <p align="left">To help growers maintain trees in their orchards at the optimum width and height, <a href="http://www.tol-inc.com" target="_blank">TOL Inc.</a>, Tulare, Calif., developed the TH1100 combination hedger/topper. Trimming trees has never been easier or faster. The TH1100 can cut both large and small citrus and deciduous trees, with the ability to maneuver in tight orchards over a wide variety of ground conditions.</p> <p align="left">Five large-diameter saws arranged at the end of individual arms on a <em>star wheel</em> (the star-shaped structure containing the saws) slice off unwanted brush, and the arms themselves help transfer the material away from the tops of trees, allowing it to fall in between rows. It ultimately improves crop yield, while preventing trees from reaching heights that are beyond the reach of human pickers.</p> <p><a href="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/TH1100.jpg"><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/TH1100.jpg" style="width: 266px; height: 353px; margin-left: 4px; margin-right: 4px; float: left;" title="The TH-1100-L combination hedger/topper can cut both large and small citrus and deciduous trees, and can maneuver within orchards over a wide variety of ground conditions. Its hydrostatic drive provides precise control for maximum productivity, safety, and reliability." /></a>Hydraulics plays a key role in virtually every operating function of the <a href="http://www.tol-inc.com/products/products/pruning-machines/th1100ct" target="_blank">TH1100</a>. It is powered by a 100-hp John Deere 4045T turbocharged engine driving an Eaton model 76 hydrostatic transmission. A gear pump provides hydraulic power for auxiliary functions: tower lift cylinder, horizontal-to-vertical positioning cylinder, cutting star swing cylinder, cutting star leveling cylinder, and engine hood lift cylinder.</p> <p>Rotation of the star wheel is driven by an <a href="http://www.eaton.com/Eaton/OurCompany/NewsEvents/NewsReleases/PCT_2173519" target="_blank">Eaton 2000</a> series low-speed, high-torque Geroler motor driven by an Eaton variable-displacement piston pump. The variable-displacement pump gives the operator precise rotational speed control for rotating the star wheel to position saw blades that are needed.</p> <p align="left">All of the machine&rsquo;s hydraulic functions can be controlled from within the operator&rsquo;s cab. Feedback from customers showed that they wanted the latest in hydraulics and simpler operation than in other machines&mdash;features TOL engineers made sure they incorporated into the TH1100.</p> <p align="left">Heavy-duty cylinders ranging in bore size from 1&frac12; to 6 in. are standard throughout, operating with a maximum pressure of 2,000 psi. The SAE 100 R2 hose used is rated well above the TH1100-L&rsquo;s maximum pressure to ensure long life and trouble-free operation. The hose is carefully routed to minimize damage from the surrounding brush.</p> <p align="left">Competing models are sickle-bar-type hedgers, which incorporate different concepts and are unable to cut very thick wood. The TH1100-L can handle wood up to 3 in. in diameter, but an experienced operator will be able to cut thicker wood with the machine. TOL has topper/hedgers operating in many countries, including the U.S., Canada, and Mexico.</p> </div> http://hydraulicspneumatics.com/agricultural/hydraulically-operated-machine-trims-orchard-trees#comments Agricultural Hydraulic Pumps & Motors Fri, 08 Jul 2016 15:41:00 +0000 39141 at http://hydraulicspneumatics.com Filtration Advice from the Experts http://hydraulicspneumatics.com/hydraulic-filters/filtration-advice-experts <div class="field-deck"> Looking for sound advice on hydraulic contamination control? Here are some tips from experts in the field. </div> <div class="node-body article-body"><table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/filtration-advice-experts-pdf-download">Download this article in .PDF format</a><br /> This file type includes high resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> <p>Sometimes you can ask 10 people the same question and get 12 different answers. That&#39;s no good if you&rsquo;re gathering eyewitness accounts of a crime. But if you&rsquo;re looking for the most effective ways to improve machine operation and reliability, the more information you have, the better.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/air-filters-and-frls/compressed-air-systems-rely-proper-filtration">Compressed Air Systems Rely on Proper Filtration</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-filters/fluid-purifier-goes-beyond-filtration">Fluid Purifier Goes Beyond Filtration</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-filters/fine-filtration-foils-hydraulic-system-failures">Fine Filtration Foils Hydraulic-System Failures</a></p> </div> <p>We queried hydraulic filtration product suppliers about some of the best practices people can follow to hold fluid contamination at bay&mdash;especially when on a tight budget. Here&#39;s a summary of their responses:</p> <p><img alt="Hydraulic filters" height="328" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/07/07/Hydraulic-filters-WEB.jpg" style="margin: 5px; float: left;" width="368" /><em>When you startup and flush a new system, consider using a finer grade of filter media for the first element used. For example, if the system uses 10 &micro;m media, start the flush with 6 &micro;m. At the next element change go back to 10 &micro;m. Benefits are: no 6-&micro;m or larger contaminant, rapid stabilization of system contamination level, minimal element usage, and greatly reduced potential of premature failure.</em></p> <p>&mdash;<a href="http://www.mpfiltriusa.com" target="_blank">MP Filtri USA Inc.</a></p> <p><em>Keep in mind that micron ratings of filter elements can be an important consideration in the operation of hydraulic systems outdoors in winter, or in extremely cold indoor environments. If a system cannot generate sufficient heat to cause the oil to flow freely through the filter, the oil will bypass the filter. Constant bypass means no filtration.</em></p> <p>&mdash;<a href="http://www.mainfilter.com" target="_blank">Main Filter Inc.</a></p> <p><em>Place filters where they can be easily serviced and replaced. The more difficult it is to see or reach a filter, the less likely it will be serviced. </em></p> <p>&mdash;<a href="http://www.zinga.com" target="_blank">Zinga Industries Inc.</a></p> <p><em>The most effective way to keep dirt and moisture out of a hydraulic reservoir is to completely seal the reservoir from the ambient environment. Replacing the air space above the fluid in the reservoir with dry nitrogen increases effectiveness by reducing oxidation of the fluid.</em></p> <p>&mdash;<a href="http://www.oiln2.com" target="_blank">Inventive Resources Inc.</a></p> <p><em>Don&#39;t judge a filter housing by its maximum operating pressure. When sizing a filter, look for the manufacturer&rsquo;s Cyclic Fatigue Rating (NFPA T2.6.1). A cyclic fatigue pressure is lower than the operating pressure and verifies the fatigue pressure rating of the pressure-containing envelope of a metal fluid power component.</em></p> <p>&mdash;<a href="http://www.schroederindustries.com" target="_blank">Schroeder Industries</a></p> <p><em>All hydraulic filters should be fitted with visual or electrical indicators or both. The visible signals allow easy and clear monitoring of the filter element status, and electrical indicators can be wired remotely to provide information at a central control panel or off-site location. Then, of course, don&#39;t ignore your indicators! If you do, and the filters go into bypass mode, you&#39;re just dumping dirty fluid back into the system. Filter bypass mode was designed to enable cold starts on mobile equipment until operating temp is reached.</em></p> <p><em>Frequent oil analysis is important in preventing problems. Don&#39;t take oil samples from the bottom drain port of the reservoir because all the big chunks of dirt and gunk fall there. Do take oil samples from a turbulent point in the system&mdash;from a working line while the system is running&mdash;to get a representative sample.</em></p> <p>&mdash;<a href="http://www.donaldson.com" target="_blank">Donaldson Co. Inc.</a></p> <p><em>The question should not be how clean can you get your oil, but how dirty can your oil be and still give you very good pump, valve, cylinder, and seal life. On the inlet side of a pump, always size the filter at least one size larger than the pump inlet port. Keep the inlet line velocity down to 4 ft/sec. </em></p> <p>&mdash;<a href="http://www.flowezyfilters.com" target="_blank">Flow Ezy Filters Inc.</a></p> <p><em>Locating a coarse filter upstream of a fine filter can improve the useful life of the fine filter by preventing larger particles from reaching the fine filter.</em></p> <p>&mdash;<a href="http://www.stauffusa.com" target="_blank">Stauff Corp.</a></p> <p><em>Remember that filters must be sized for maximum flow, not average flow. Use the largest capacity filter that you can fit into available space, with flow capability at least twice that of maximum times flow.</em></p> <p>&mdash;<a href="http://www.rosedaleproducts.com" target="_blank">Rosedale Products Inc.</a></p> <p><em>When sizing a filter, remember to consider startup conditions. During startup or cold operating conditions, fluid viscosity may be higher than during operating conditions, meaning that a larger sized filter may be required. In addition, when ∆P indicator is used, a thermal lock should be considered to prevent premature tripping until the fluid reaches normal operating temperature.</em></p> <p><em>Finer filtration is not always better. If equipment requires 10 &micro;m, 3-&micro;m filtration does not necessarily provide a better option. The 3-&micro;m element will clog faster, resulting in more frequent element changes, and higher service and product costs.</em></p> <p>&mdash;<a href="http://www.hydac-na.com" target="_blank">HYDAC International</a></p> <p><em>It&#39;s a common misconception that coarse filters last longer than fine filters. This is not really the case. Once a fine filter has removed particles from the system and stopped wear from occurring, there are few particles left to be removed&mdash;and thus, long life. On the other hand, a coarse filter doesn&#39;t prevent wear, so particles will continually need to be removed.</em></p> <p>&mdash;<a href="http://www.pall.com" target="_blank">Pall Corp.</a></p> <p><em>Desiccant breathers have become the new standard for keeping dirt and moisture out of hydraulic reservoirs. Use them to remove dirt and moisture that would otherwise be drawn into the reservoir during normal equipment cycling.</em></p> <p>&mdash;<a href="http://descase.com" target="_blank">Des-Case Corp.</a></p> <p><em>Record inspection and replacement intervals where they can be observed and compared. As frequency of replacement increases, it&#39;s a warning of component failure. When you do replace a filter element, inspect it for trapped metal. An increase in yellow metal shows a failure in wear plates or slippers. An increase in white and gray (ferrous) metals indicates wear caused from contamination or cavitation. Black, carbonaceous material; sticky, gooey varnish; or gray ash may indicate excessive heat and signal time for an oil change. Inspect the system to determine what is causing the heat.</em></p> <p>&mdash;<a href="http://www.ntzfilter.com" target="_blank">NTZ Microfiltration</a></p> <p><em>Consider using a portable filter cart for large mobile systems exposed to dirty environments. Portable filter carts can be your best investment by keeping multiple machines clean without having to install a kidney loop on each machine.</em></p> <p>&mdash;<a href="http://www.munciepower.com" target="_blank">Muncie Power Products</a></p> <p><em>New oil is never clean. Therefore, do not add fluid to a system without pouring it through a filling filter. This fine-mesh filter should be rated at least &beta;<sub>10</sub> 75 (10 &micro;m absolute).</em></p> <p>&mdash;<a href="http://www.moog.com" target="_blank">Moog Inc.</a></p> <p><em>If you&#39;re not sure when to change a filter, install a pressure differential indicator on the filter adapter. All the guesswork is gone!</em></p> <p>&mdash;<a href="http://www.cim-tek.com" target="_blank">Central Illinois Mfg. Co.</a></p> <p><em>Inspect used filters as a predictive maintenance tool. If metal debris is noticed on the surface of the filter media, good magnification and wear metal analysis can pinpoint the source of the metal. This way, components that will obviously break down soon can be changed out during a scheduled down period. Many thousands of dollars can be saved by practicing predictive&mdash;rather than reactive&mdash;maintenance.</em></p> <p>&mdash;<a href="http://www.triple-rrr.com" target="_blank">Triple R America Co. Ltd.</a></p> <p><em>The level of filtration is only as good as the weakest filtration component&mdash;a 3 &micro;m absolute return line filter doesn&#39;t mean 3 &micro;m oil if the reservoir breather is 50 &micro;m.</em></p> <p>&mdash;<a href="http://www.ptitechnologies.com" target="_blank">PTI Technologies Inc.</a></p> <p><em>Typical oil additives, such as anti-oxidant agents, will compensate and balance chemical changes from oxidation. If oil oxidation has not been minimized, oil additives and base oil will transform into oxidation byproducts&mdash;waxy residues on valve surfaces and sludge on the bottom of the reservoir.</em></p> <p>&mdash;<a href="http://oilpure.com" target="_blank">OilPure Technologies Inc.</a></p> <p><em>Looking for parts? Go to&nbsp;<a href="http://www.SourceESB.com" target="_blank">SourceESB</a>.</em></p> <table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/filtration-advice-experts-pdf-download">Download this article in .PDF format</a><br /> This file type includes high resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> </div> http://hydraulicspneumatics.com/hydraulic-filters/filtration-advice-experts#comments Hydraulic Filters Thu, 07 Jul 2016 15:01:00 +0000 39091 at http://hydraulicspneumatics.com Filtration Advice from the Experts (.PDF Download) http://hydraulicspneumatics.com/datasheet/filtration-advice-experts-pdf-download <div class="node-body datasheet-body"><p>Sometimes you can ask 10 people the same question and get 12 different answers. That&rsquo;s no good if you&rsquo;re gathering eyewitness accounts of a crime. But if you&rsquo;re looking for the most effective ways...</p> <p><strong>Register or sign in below to download the full article in .PDF format, including high resolution graphics and schematics when applicable.</strong></p> <div class="gatedLogin well"> <div class="contentPadding clearfix"> <h2>Register for Complete Access (Valid Email Required)</h2> <p><p><img height="auto" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2015/08/full-wallchart.JPG" width="100%" />By registering on Hydraulics &amp; Pneumatics now, you&#39;ll not only gain access to , you&#39;ll also receive a complimentary copy of <em>Hydraulics & Pneumatics Wall Chart</em>.</p> </p> <div class="gatedLoginButtons gated-register-button"> <div class="button-region"> <a href="/penton_ur/nojs/user/register?source=gated&nid=39121&regmode=1" class="ctools-use-modal btn btn-branded btn-wide ctools-modal-register" title="Register at this site.">Register</a> </div> <div class="loginLinkText"> Already registered? <a href="/penton_ur/nojs/login" class="ctools-use-modal ctools-modal-log_in" title="">Log In</a> here. </div> </div> </div> </div> </div> Gold Thu, 07 Jul 2016 14:21:00 +0000 39121 at http://hydraulicspneumatics.com Troubleshooting Challenge: Hydraulic System Overheats in Aluminum Recycling Plant http://hydraulicspneumatics.com/hydraulic-valves/troubleshooting-challenge-hydraulic-system-overheats-aluminum-recycling-plant <div class="node-body article-body"><table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/troubleshooting-challenge-hydraulic-system-overheats-aluminum-recycling-plant-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/ThinkstockPhotos-518887756_web.jpg" style="width: 595px; height: 396px;" /></p> <p>An aluminum recycling and smelting plant has a hydraulic feeder unit that pushes scrap aluminum into a smelting furnace. Once melted, the aluminum flows to other equipment that separates impurities and directs the relatively pure aluminum into large molds, where it solidifies as ingots. After the ingots have cooled, they are ready to be shipped to customers.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/cylinders-actuators/troubleshooting-challenge-leaking-cylinder-puzzles-expert">Troubleshooting Challenge: Leaking Cylinder Puzzles Expert</a></p> <p><a href="http://hydraulicspneumatics.com/hose-tubing/troubleshooting-challenge-hoses-pull-away-fittings">Troubleshooting Challenge: Hoses Pull Away from Fittings</a></p> <p><a href="http://hydraulicspneumatics.com/cylinders-actuators/troubleshooting-challenge-hpu-too-noisy">Troubleshooting Challenge: HPU Is Too Noisy</a></p> </div> <p>The feeder uses a hydraulic cylinder at the bottom of a feed chute to shear the incoming scrap aluminum and push it into the furnace. The cylinder operates at a rate determined by a motion controller, which receives several feedback signals from the machine (such as how fast the aluminum melts, the scrap feed rate, and weights).</p> <p>The hydraulic feeder circuit is fairly simple: It uses a 40-gpm pumping system with a 1-gpm pump for pilot pressure to reduce pilot-pressure heat generation when the cylinder is idle. A pilot-operated directional-control valve was sized large enough to keep pressure under 10 psi when its spool is centered. Both the relief valve and directional valve were mounted on a customer-supplied manifold.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/accumulator-W-Callouts_web.jpg" style="width: 595px; height: 335px;" /></p> <p>The system ran fine for several years until a crane hook inadvertently caught hold of the pilot valve and ripped it off the main stage. As a result, the pilot valve was replaced with a new one.</p> <p>The repaired system did not undergo any heat buildup during the idle phase, but a heating problem occurred when the system was cycling. If the system was allowed to idle for a period, its temperature would drop. Operators also noticed that the cylinder was operating at a slower speed.</p> <p>Plant personnel called us in to add a heat exchanger to control the overheating problem. But we convinced them that they should resolve the problem rather than just treating the symptom.</p> <p>They had already replaced both relief valves and used a flow meter to confirm that the pump output was close to the rated flow. We confirmed the cylinder was not bypassing.</p> <p>Any idea what was causing the heat and slow cylinder operation?</p> <p><strong>Find the Solution</strong></p> <p>Think you know the answer to this month&rsquo;s problem? Submit your solution by emailing Mindy Timmer at <a href="mailto:timmer@cfc-solar.com">timmer@cfc-solar.com</a>. All correct solutions submitted by August 8, 2016 will be entered into a random drawing for a $50 gift card. The winner will be notified, and his or her name will be printed in a future issue. Only one gift card will be awarded to any participant within a calendar year.</p> <p>Congratulations to Ryan Funk, of Peoria, Ill., who won our June puzzler by having his name picked from those who correctly answered that problem. A $50 gift card is in the mail to him.</p> <p><strong>Solution to Last Month&rsquo;s Problem: <a href="http://hydraulicspneumatics.com/cylinders-actuators/troubleshooting-challenge-leaking-cylinder-puzzles-expert" target="_blank">Leaking Cylinder Puzzle Expert</a></strong></p> <p>After finding a puddle of oil under a forklift&mdash;even though no leak was found after a test run&mdash;I called in our seal provider. After we explained the circumstances, he told us, &ldquo;The hardest thing to seal is a cylinder with NO pressure in it.&rdquo; That was why we could not get the returned cylinders to leak when we tested them, and why the cylinder didn&rsquo;t leak in the test run.</p> <p>Our seal guy recommended that we stop using the factory seal kit the dealer was supplying us. Instead, we should use a different seal design made from a slightly softer material. It solved our leaking rod seal problem from that point on.</p> <p><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></p> <table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/troubleshooting-challenge-hydraulic-system-overheats-aluminum-recycling-plant-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> </div> http://hydraulicspneumatics.com/hydraulic-valves/troubleshooting-challenge-hydraulic-system-overheats-aluminum-recycling-plant#comments Accumulators Cylinders & Actuators Hydraulic Valves Thu, 07 Jul 2016 13:54:00 +0000 39101 at http://hydraulicspneumatics.com ¿Comprende Hidráulica y Neumática en Español? http://hydraulicspneumatics.com/blog/comprende-hidr-ulica-y-neum-tica-en-espa-ol <div class="node-body blog-body"><table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/comprende-hidr-ulica-y-neum-tica-en-espa-ol-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> <p>My eighth-grade Spanish teacher, Mrs. Keck, would&rsquo;ve been proud that I remembered some Spanish after all these years. Actually, I cheated with the headline a little because I went to a couple online translation pages to check my work. (And for the record, the headline reads, &ldquo;Do you understand hydraulics and pneumatics in Spanish?&rdquo;)</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/blog/principios-ingenieriles-b-sicos-circuitos-de-presi-n">Principios Ingenieriles B&aacute;sicos - Circuitos de Presi&oacute;n</a></p> <p><a href="http://hydraulicspneumatics.com/blog/filtraci-n-fina-previene-fallas-en-sistemas-hidr-ulicos">Filtraci&oacute;n fina previene fallas en sistemas hidr&aacute;ulicos</a></p> <p><a href="http://hydraulicspneumatics.com/blog/cavitaci-n-en-un-sistema-hidr-ulico">Cavitaci&oacute;n en un sistema hidr&aacute;ulico</a></p> </div> <p>So why ask if you know fluid power in Spanish? Well, if Spanish isn&rsquo;t your native language, you probably know or work with people whose native language is Spanish. But what does that have to do with fluid power?</p> <p>All of us are probably aware of the need for fluid-power education and training in our industry. It seems as though an awful lot of people working in the field would like to improve the knowledge of fluid-power technology&mdash;whether its reading schematics, knowing the best practices for preparing and installing components, learning how to effectively troubleshoot systems, and how to work safely around fluid-power systems.</p> <p>Fluid power isn&rsquo;t taught in most schools, so it&rsquo;s usually up to individuals to learn about the technology on their own. But it can be a real problem finding the information you need, because no single, all-encompassing source of fluid-power information exists&mdash;not even <em>hydraulicspneumatics.com</em>.</p> <p>Most of these issues, of course, are addressed in training and certification from the <a href="http://www.ifps.org" target="_blank">Fluid Power Society</a>. Although none of the material is written in Spanish, Donna Pollander, executive director of IFPS, says that the IFPS executive board is aware of the need and has begun investigating its feasibility.</p> <p>This brings me to Ricardo J. Sol&oacute;rzano, founder and general manager of <a href="http://www.eemtechnologies.com/#!home/cb4h" target="_blank">EEM Technologies Corp.</a>, Miami. Ricardo contacted me a few months ago and mentioned that he has read <em>Hydraulics &amp; Pneumatics</em> for years and how informative he finds our website. EEM serves customers in Central America, the Caribbean, and northern parts of South America. Like most people in the industry, Ricardo knows his customers could benefit from expanding their knowledge of fluid power. However, his customers have the additional challenge of needing to learn about fluid power in Spanish.</p> <p>So Ricardo and I worked out a way for him to translate some of the most popular content on the H&amp;P website into Spanish. As result, I am proud to announce that Ricardo&rsquo;s blog, &ldquo;<a href="http://hydraulicspneumatics.com/blog/hp-en-tu-idioma" target="_blank"><em>H&amp;P</em> en tu idioma!</a>&rdquo;, now appears on our home page. Ricardo has entered seven blogs as of this writing, and we should have dozens by the end of the year&mdash;equivalent to what you&rsquo;d find in a small book.</p> <p>Unfortunately, my Spanish is not good enough to translate the title of Ricardo&rsquo;s blog into Spanish, but he tells me it means &ldquo;<em>H&amp;P</em> in your language.&rdquo; So feel free to spread the word. I&rsquo;m sure your Spanish-speaking colleagues in fluid power will appreciate it.</p> <p><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></p> <table border="0" cellpadding="0" cellspacing="0" width="570"> <tbody> <tr> <td width="41"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" /></td> <td style="padding-left: 0px;" width="459"><a href="/datasheet/comprende-hidr-ulica-y-neum-tica-en-espa-ol-pdf-download">Download this article in .PDF format</a><br /> This file type includes high-resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> </div> http://hydraulicspneumatics.com/blog/comprende-hidr-ulica-y-neum-tica-en-espa-ol#comments Community The Hitch Post Wed, 06 Jul 2016 19:19:00 +0000 39071 at http://hydraulicspneumatics.com Hydraulic Diagrams You Should Not Do Without http://hydraulicspneumatics.com/blog/hydraulic-diagrams-you-should-not-do-without <div class="node-body blog-body"><p>A picture is worth a thousands words. And so is an accurate hydraulic diagram. It can also be worth a lot of nickel. Consider the four main types of hydraulic diagrams in common use -- and the consequences of having to manage without them:<br /> <br /> <strong>Block Diagrams</strong> show the components of a hydraulic circuit as blocks joined by lines, which indicate connections and/or interactions.<br /> <br /> <strong>Cutaway Diagrams</strong> show the internal construction of hydraulic components and their flow paths. Because these diagrams typically use colors, shades or patterns in the lines and passages, they are very effective at illustrating different flow and pressure conditions.<br /> <br /> <strong>Pictorial Diagrams</strong> show a hydraulic circuit&#39;s components and piping arrangement. The hydraulic components are seen externally and are usually in a close reproduction of their actual shapes in scaled sizes. This aids in hydraulic component recognition and identification.<br /> <br /> <strong>Graphical Diagrams</strong> are the shorthand system of the fluid power hydraulics industry. They comprise simple, geometric symbols, drawn to ANSI or ISO standards that represent the hydraulic components, their controls and connections.<br /> <br /> To a hydraulic technician skilled in reading and interpreting them, a graphical circuit diagram or schematic is a valuable aid in identifying possible causes of a problem. And this can save a lot of time and money in a hydraulic troubleshooting situation.<br /> <br /> If a hydraulic schematic diagram is not available, the technician must manually trace the actual, physical circuit and identify its components in order to isolate possible causes of the problem. This can be a time-consuming process, depending on the complexity of the hydraulic system.<br /> <br /> Worse still, if the hydraulic circuit contains a valve manifold, the manifold may have to be removed and dismantled - just to establish what it&#39;s supposed to do. Because if the function of a component within a hydraulic system is not known, it can be difficult to discount it as a possible cause of the problem.Schematic diagrams eliminate the need to reverse engineer the hydraulic system.<br /> <br /> A picture may be worth a thousand words, but THIS one can be worth a thousand dollars (or more!). In other words, not keeping track of your hydraulic drawings or failing to keep them up to date can be a costly mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=smr"><strong>get &quot;Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!&quot; available for FREE download here</strong></a>.</p> </div> http://hydraulicspneumatics.com/blog/hydraulic-diagrams-you-should-not-do-without#comments Hydraulics At Work Tue, 05 Jul 2016 00:22:00 +0000 39061 at http://hydraulicspneumatics.com Filtración fina previene fallas en sistemas hidráulicos http://hydraulicspneumatics.com/blog/filtraci-n-fina-previene-fallas-en-sistemas-hidr-ulicos <div class="node-body blog-body"><p class="rtejustify">La contaminaci&oacute;n es el enemigo mortal de los sistemas hidr&aacute;ulicos, de hecho, m&aacute;s del 80% de las fallas en los mismos pueden ser atribuidas a fluidos contaminados. En esto incluimos&nbsp;fallas en mangueras y conexiones, as&iacute; como tambi&eacute;n&nbsp;de&nbsp;bombas, motores y v&aacute;lvulas.</p> <p class="rtejustify">La relaci&oacute;n entre&nbsp; la contaminaci&oacute;n de fluidos y la vida &uacute;til de los componentes es tan consistente que los fabricantes originales de hidr&aacute;ulica y filtraci&oacute;n publican gr&aacute;ficos que pueden ser utilizados para predecir las consecuencias de una filtraci&oacute;n inadecuada, como se muestra en la Figura 2. Adem&aacute;s, a medida que aumentan las presiones de operaci&oacute;n y las tolerancias en los componentes se hacen m&aacute;s ajustadas en la b&uacute;squeda de obtener una mayor eficiencia, existe el potencial de que estas part&iacute;culas causen un da&ntilde;o a&uacute;n mayor al sistema hidr&aacute;ulico.</p> <p class="rtejustify">A pesar que los&nbsp;usuarios de equipo hidr&aacute;ulico indus<img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Hydraulic%20Filtration-Lead.gif" style="width: 300px; height: 267px; margin: 10px; float: right;" title="Figura 1: La mayoría de las partículas de contaminantes no pueden ser vistas a simple vista, por lo que la implementación de sistemas de monitoreo de contaminación es esencial para mantener un sistema con una alta confiabilidad" />trial han lidiado con este problema por mucho tiempo, solo recientemente est&aacute; tomando fuerza en el mundo de la maquinaria m&oacute;vil, donde filtros enroscables y mantenimiento de fluidos basado en el tiempo de utilizaci&oacute;n son aun la pr&aacute;ctica com&uacute;n. Ninguna de esas tecnolog&iacute;as, sin embargo, son suficientes para proteger los sistemas hidr&aacute;ulicos&nbsp;<span style="font-size: 12.8px; line-height: 20px; text-align: justify;">de</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">&nbsp;</span>alta<span style="font-size: 12.8px; line-height: 20px; text-align: justify;">&nbsp;presi&oacute;n&nbsp;</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">y&nbsp; </span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">d</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">esem</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">pe&ntilde;o</span> actualmente<span style="font-size: 12.8px; line-height: 20px; text-align: justify;">&nbsp;</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">uti</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">liza</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;">dos</span><span style="font-size: 12.8px; line-height: 20px; text-align: justify;"> en la</span>&nbsp;maquinaria m&oacute;vil.</p> <p class="rtejustify"><strong>Cuantificaci&oacute;n de la contaminaci&oacute;n</strong></p> <p class="rtejustify">Lo que requieren los sistemas hidr&aacute;ulicos es filtraci&oacute;n absoluta, la cual se define a trav&eacute;s de una medici&oacute;n de desempe&ntilde;o conocida como la raz&oacute;n Beta producida por la Prueba de Desempe&ntilde;o de Filtro por el M&eacute;todo de Paso M&uacute;ltiple &nbsp;seg&uacute;n ISO 16889:2008. Los resultados de la prueba se reportan mediante la raz&oacute;n Beta que se obtiene dividiendo&nbsp;el n&uacute;mero de part&iacute;culas por encima del tama&ntilde;o especificado&nbsp;aguas arriba del filtro, entre el n&uacute;mero de &eacute;stas aguas abajo del mismo.</p> <p class="rtejustify">Los sistemas hidr&aacute;ulicos modernos requieren una filtraci&oacute;n con un nivel Beta de 200 (99.5% de las part&iacute;culas contaminantes removidas), o 1,000 (99.9%) para maximizar la vida &uacute;til del equipo. Pero &eacute;ste valor es solo el comienzo de la historia de limpieza en sistemas hidr&aacute;ulicos.</p> <p class="rtejustify">La capacidad de retenci&oacute;n de s&oacute;lidos de un filtro, caracter&iacute;sticas de ca&iacute;da de presi&oacute;n, y la estabilidad del nivel Beta tambi&eacute;n son de importancia. La estabilidad del nivel Beta es la capacidad que tiene un elemento filtrante de proveer un buen desempe&ntilde;o en los sistemas hidr&aacute;ulicos utilizados en la realidad, que presentan gran dinamismo, no s&oacute;lo en un laboratorio. En t&eacute;rminos pr&aacute;cticos, esto significa que un filtro de cartucho es casi siempre la mejor alternativa.</p> <p class="rtecenter"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/uploads/2015/03/RecFluidClean-TABLE.gif" style="width: 595px; height: 1594px;" title="Figura 2: Niveles de limpieza recomendados para componentes diversos" /></p> <p class="rtejustify">Los mejores filtros de cartucho actualmente utilizados tienen m&uacute;ltiples capas de material sint&eacute;tico para maximizar el desempe&ntilde;o en todas las &aacute;reas. Cada una proporciona una funci&oacute;n espec&iacute;fica que mejora el desempe&ntilde;o, capacidad de retenci&oacute;n de part&iacute;culas, o la estabilidad Beta.</p> <p class="rtejustify">Los filtros de tipo cartucho tambi&eacute;n reducen considerablemente la p&eacute;rdida de fluidos que ocurre cada vez que un filtro enroscable se reemplaza, lo que resulta en un impacto positivo a nivel econ&oacute;mico y ambiental. Consider&aacute;ndolos junto con la extensi&oacute;n de vida &uacute;til esperada en un sistema correctamente protegido, estos factores f&aacute;cilmente justifican el costo levemente superior de los filtros de cartucho.</p> <p class="rtejustify">Los filtros de cartucho son el est&aacute;ndar en aplicaciones de hidr&aacute;ulica industrial. Se est&aacute; observando igualmente una adopci&oacute;n de esta tecnolog&iacute;a en el ambiente m&oacute;vil, donde tambi&eacute;n se ve un aumento en las presiones de operaci&oacute;n y en la sofisticaci&oacute;n de los componentes utilizados.</p> <p class="rtejustify"><strong>Retos de la hidr&aacute;ulica m&oacute;vil y soluciones</strong></p> <p class="rtejustify">Las limitaciones de espacio representan una consideraci&oacute;n mayor en el dise&ntilde;o de equipo hidr&aacute;ulico m&oacute;vil, y los componentes adicionales requeridos en sistemas de control de emisiones que cumplan con Tier-4 en motores diesel, la hacen a&uacute;n m&aacute;s cr&iacute;tica. Una estrategia exitosa para minimizar la huella de los sistemas de filtraci&oacute;n es la de utilizar filtros sobre tanque integrados al reservorio. Los fabricantes de filtros han desarrollado un n&uacute;mero de dise&ntilde;os para esta aplicaci&oacute;n con &eacute;xito y algunos fabricantes de reservorio ahora ofrecen versiones pre-instaladas como est&aacute;ndar. Esta tendencia de seguro se acelerar&aacute; en vista al aumento de las exigencias de emisiones a nivel global.</p> <p class="rtejustify">Problemas de arranque en fr&iacute;o son tambi&eacute;n &uacute;nicos en el ambiente m&oacute;vil. Los fluidos hidr&aacute;ulicos aumentan su viscosidad a bajas temperaturas, lo que aumenta la ca&iacute;da de presi&oacute;n a trav&eacute;s del elemento filtrante. El desempe&ntilde;o se degrada hasta que el fluido alcance la temperatura de operaci&oacute;n. Este fen&oacute;meno generalmente se relaciona con comentarios del operador que dice &ldquo;arranqu&eacute; y accion&eacute; la palanca, pero no pas&oacute; nada.&uml;</p> <p class="rtejustify">Instalar un filtro m&aacute;s grande es una soluci&oacute;n, pero le agrega costo y tama&ntilde;o al sistema. Otra idea es la de desviar el flujo hacia una v&aacute;lvula de presi&oacute;n sin pasar por el filtro hasta que el fluido alcance la temperatura de operaci&oacute;n. Lo malo de este m&eacute;todo es que existe el potencial de enviar contaminaci&oacute;n aguas abajo del mismo. Una soluci&oacute;n m&aacute;s pr&aacute;ctica consiste en la utilizaci&oacute;n de una v&aacute;lvula de desv&iacute;o o <em>bypass</em>, pero que regresa el fluido no filtrado al tanque en vez de dejar que circule por el sistema.</p> <p class="rtejustify"><strong>Alcanzar metas realistas</strong></p> <p class="rtejustify">Con la tecnolog&iacute;a de filtraci&oacute;n disponible actualmente, una meta alcanzable para la&nbsp; maquinaria m&oacute;vil es la de reducir el nivel de contaminaci&oacute;n hasta el punto que no contribuya a la falla de ning&uacute;n componente del sistema en lo que es considerada la vida &uacute;til razonable del componente en cuesti&oacute;n. Para llegar ah&iacute;, primero se debe fijar un nivel de limpieza target que considere las necesidades espec&iacute;ficas de operaci&oacute;n del sistema.</p> <p class="rtejustify">La limpieza es un valor cuantitativo muy espec&iacute;fico al que se llega utilizando un sistema de conteo de part&iacute;culas definido por la norma ISO 4406:99. Es algo complejo explicarlo en este art&iacute;culo en detalle, pero el valor clave es el c&oacute;digo de limpieza de tres n&uacute;meros, por ejemplo: 17/14/12, que representan el n&uacute;mero de part&iacute;culas de un tama&ntilde;o espec&iacute;fico encontrado en una muestra de aceite.</p> <p class="rtejustify">Las tablas de falla de componentes mencionadas anteriormente est&aacute;n basadas en niveles de limpieza aplicados a los componentes m&aacute;s sensibles a la contaminaci&oacute;n. Profesionales en el &aacute;rea de fluidos la deben utilizar como gu&iacute;a para definir niveles de limpieza target para sistemas hidr&aacute;ulicos particulares.</p> <p class="rtejustify">Luego de definir esos niveles, la &uacute;nica manera de medir el &eacute;xito es monitoreando las condiciones del fluido sistem&aacute;ticamente. Por lo general, muestras de aceite son enviadas a un laboratorio para ser analizadas, lo que no es siempre f&aacute;cil de hacer con equipo m&oacute;vil. Por suerte, varios fabricantes como Hydac, Bosch Rexroth e Eaton, ofrecen soluciones de filtraci&oacute;n tanto en maletines como de monitoreo constante, que pueden ser utilizadas para cumplir este fin (para mayor informaci&oacute;n les dejamos el siguiente <em><a href="http://www.boschrexroth.com/ics/Vornavigation/VorNavi.cfm?Language=EN&amp;DisplayType=tile&amp;Region=none&amp;VHist=Start&amp;PageID=p537442">enlace</a></em>).</p> <p class="rtejustify">Las fuentes de contaminaci&oacute;n en sistemas m&oacute;viles son tan variadas que se podr&iacute;an escribir varios art&iacute;culos al respecto, pero el punto clave es el siguiente: nunca asuma que el fluido que entra al sistema est&aacute; limpio a menos que sea filtrado cuando se ingrese al reservorio. Los filtros de cartucho son una de las herramientas de mayor valor relativo disponibles para el mantenimiento de un sistema hidr&aacute;ulico y se pagar&aacute; por s&iacute; mismo varias veces al extender la vida &uacute;til de componentes de alto costo.</p> <p class="rtejustify"><strong>Construir una estrategia</strong></p> <p class="rtejustify">&nbsp;Una estrategia de filtraci&oacute;n bien planificada y aplicada consistentemente, dise&ntilde;ada alrededor de tecnolog&iacute;as de filtraci&oacute;n de cartucho y el monitoreo sistem&aacute;tico del fluido extender&aacute; la vida &uacute;til de componentes hidr&aacute;ulicos cr&iacute;ticos y aumentar&aacute; la productividad y disponibilidad del equipo m&oacute;vil. Igualmente extender&aacute; la vida &uacute;til del fluido hidr&aacute;ulico y permitir&aacute; una reducci&oacute;n en el costo de desecho de fluidos y elementos filtrantes.</p> <p class="rtejustify">El ignorar la necesidad de filtraci&oacute;n conllevar&aacute; a efectos destructivos en el sistema y por ende a las ganancias de su empresa. Las soluciones existen &ndash; es hora de ponerlas en acci&oacute;n.</p> <p class="rtejustify">&nbsp;</p> <p><em>Ricardo Sol&oacute;rzano trabaja en EEM Technologies Corp., un distribuidor de soluciones en tecnolog&iacute;as de fluido para los mercados de Latinoam&eacute;rica. Para mayor informaci&oacute;n puede contactarlo al: <a href="tel:+1(855)462-7633">+1(855)462-7633</a>, <a href="mailto:info@eemtechnologies.com">info@eemtechnologies.com</a>, <a href="http://www.eemtechnologies.com">www.eemtechnologies.com</a>.</em></p> <p>&nbsp;</p> </div> http://hydraulicspneumatics.com/blog/filtraci-n-fina-previene-fallas-en-sistemas-hidr-ulicos#comments Fluid Cleanliness Hydraulic Filters H&amp;P en tu idioma! Mon, 04 Jul 2016 21:48:00 +0000 39051 at http://hydraulicspneumatics.com