Hydraulics & Pneumatics - Hydraulics & Pneumatics is the leading international technical resource for fluid power http://hydraulicspneumatics.com/rss.xml en Rewards of Purchasing Reman Units http://hydraulicspneumatics.com/hydraulic-pumps-motors/rewards-purchasing-reman-units <div class="field-deck"> Sponsored by Fluidyne </div> <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/FluiDyne-Logo-199x70.gif" style="width: 150px; height: 53px; float: right;" />When you choose a Remanufactured product with FluiDyne Fluid Power you are getting a unit that performs to the same specifications as new, costs less, has an 18 month warranty and is helping the environment all at the same time.&nbsp;</p> <p><br /> <script type="text/javascript"> document.write('\ <iframe style="height: 750px; width: 100%; border:0;” frameBorder="0" scrolling="no"\ src="http://pages.hydraulicspneumatics.com/HP_Digital_Fluidyne-RewardsRemanUnits_WP_JR_042916?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></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/hydraulic-pumps-motors/rewards-purchasing-reman-units#comments White Papers Hydraulic Pumps & Motors Thu, 05 May 2016 18:33:00 +0000 38101 at http://hydraulicspneumatics.com Controlling the Biggest Water Show on Earth http://hydraulicspneumatics.com/controls-instrumentation/controlling-biggest-water-show-earth <div class="field-deck"> When heavy loads and precise motion control with pinpoint repeatability are needed, electrohydraulics is a frequent choice—even when operations occur under water. </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/controlling-biggest-water-show-earth-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>Taking in Franco Dragone&rsquo;s <em>The House of Dancing Water</em> production in Macau, China&rsquo;s City of Dreams, is breathtaking. Sophisticated staging is actually composed of eight different lift sections. The stage <em>(Fig. 1)</em> sits atop a forest of hydraulic cylinders <em>(Fig. 2)</em> that lift and lower the sections up to&nbsp; 27 ft. in the world&rsquo;s largest indoor swimming pool. At times the lifts are raised to form a dry stage and at other times, they independently recede to produce a water pool for swimmers, only to emerge again carrying large props such as a pagoda structure <em>(Fig. 3)</em> and a 26-ton ship <em>(Fig. 4)</em>.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/entertainment/hydraulics-set-stage-biggest-water-show-earth">Hydraulics Set the Stage at the Biggest Water Show on Earth</a></p> <p><a href="http://hydraulicspneumatics.com/200/IndZone/Entertainment/Article/False/87632/IndZone-Entertainment">Spider-Man musical relies on the power of hydraulics to control and lift stages and platforms</a></p> <p><a href="http://hydraulicspneumatics.com/200/TechZone/Cylinders/Article/False/9467/TechZone-Cylinders?page=3">Hydraulics joins the Cirque</a></p> </div> <p>The cylinders are controlled by a bank of 11 RMC150 electrohydraulic motion controllers <em>(Fig. 5)</em> manufactured by <a href="http://sourceesb.com/manufacturers/search?q=Delta%20Computer%20Systems" target="_blank">Delta Computer Systems</a>. Four hydraulic cylinders (mounted symmetrically underneath) actuate each main platform section&mdash;for a grand total of 32 motion axes controlling the main platform sections. Another 18 axes operate three performers&rsquo; entry and exit ramps (each ramp, called a vomitorium, has six axes of control for lift, extension, and tilt). All main platform cylinders are controlled by remote valve manifolds located in the basement of the theater beneath the pool, and the cylinders are mounted to the pool floor inside submerged concrete caissons.</p> <p><img alt="Fig. 1" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Delta-Fig-1_.jpg" style="margin: 5px; float: left; width: 331px; height: 248px;" title="1. The stage used in The House of Dancing Water production is composed of 12 sections that can be raised and lowered independently for a wide range of effects." />Because the theater is constructed with separate water-holding and dry enclosures, the hydraulic valves and cylinders are located a distance apart, with a large amount of hydraulic oil (on average 70 gal) in each cylinder and in the plumbing between the cylinder and its valve. To keep the platform sections level and avoid deforming the structural frames, motion of each cylinder operating a lift must be tightly synchronized with each other. This requirement is made even more challenging by the compressibility of the volume of hydraulic oil between each valve and cylinder.</p> <p>To provide the hydraulic components for this large and complex application, <a href="http://www.comoso.com" target="_blank">Controlled Motion Solutions (Comoso)</a>, Santa Ana, Calif., was hired by the general contractor, Handling Specialty of Grimsby, Ontario, Canada. Comoso&rsquo;s system engineering manager, Matt Schoenbachler, headed up the design of the overall hydraulic system and all associated hardware. The team worked with Parker-Hannifin to design custom double-acting cylinders to control the platforms.&nbsp;</p> <p><img alt="Fig. 2" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Delta-Fig-2.jpg" style="margin: 5px; float: right; width: 240px; height: 321px;" title="2. Here is a view of the hydraulic cylinders in the empty pool under the stage. The LMDT rods are visible next to the cylinder rods." />Each cylinder has an 8-in. bore with a 7-in. rod and a 324.8-in. (27 ft.) stroke. The cylinders are fed by Parker servo-quality proportional valves. To provide a measure of its position, each cylinder is instrumented with a 27-ft. long magnetostrictive linear displacement transducer from MTS Sensors. Hydraulic fluid to operate the system is pumped from a 3,500-gal reservoir by 21 Parker PV variable-displacement piston pumps and T7 fixed-displacement vane pumps. In total, the pumps can deliver up to 1,671 gpm of pressurized fluid. The pumps are driven by seven electric motors that can transmit up to 2,100 hp.</p> <h3>Accounting for Compliance</h3> <p>As mentioned earlier, synchronizing the motion of the multiple cylinders operating each stage panel provided challenges to the designers. &ldquo;Because of the compressibility (compliance) of the large volumes of hydraulic oil contained in the plumbing and cylinder assembly itself, we understood that a simple PID control algorithm would be difficult to tune in this application, and only a Delta Computer Systems controller would have a chance of providing favorable results,&rdquo; says Schoenbachler. Even with control loop gains set to low values, starts and stops could still cause the system to oscillate.&nbsp; &nbsp;&nbsp;</p> <p>The team&rsquo;s software developer tuned the system in consultation with Delta Computer Systems engineer Dennis Ritola. The team solved the problem by augmenting a proportional-integral-derivative (PID) algorithm in the motion controller with an additional control equation factor in order to avoid the oscillations. &ldquo;We avoided the oscillation problem by adding a second derivative gain term to the control equation to compensate for the springiness of the system,&rdquo; says Ritola.</p> <p><img alt="Fig. 3" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Delta-Fig-3.jpg" style="margin: 5px; float: left; width: 360px; height: 239px;" title="3. A pagoda is one of the large scenery items that can be lifted out of the water on the central stage panel." />Introducing the second-derivative gain element requires that position feedback information be converted to measured accelerations. However, doing so can &ldquo;create&rdquo; significant high-frequency noise in the measurements and the resulting control output. &ldquo;In this case, to cancel the output noise effects, we recommended adding a low-pass filter to the control output that drives the valves,&rdquo; explains Ritola. &ldquo;This eliminated the output noise and allowed the control axes to be properly tuned.&rdquo; When the process was finished, the stage platforms moved and positioned smoothly with no oscillations.&nbsp;</p> <h3>Solving Another Challenge</h3> <p>In addition to compensating for the capacitive effects of the long hydraulic lines, the controllers must compensate for dynamic changes in the loads on the cylinders as a lift floor breaks the surface of the water in order to keep the motion of the lifts smooth. The challenge is dealing with the buoyancy of the platforms. As a platform moves up out of the water, its effective load increases because it is no longer counteracted by the buoyancy from the water. The system design specification dictates that the extensions of the cylinders operating any lift never differ by more than 5 mm dynamically, while moving at a rate of 4 in./sec.</p> <p><img alt="Fig. 4" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Delta-Fig-4.jpg" style="margin: 5px; float: right; width: 293px; height: 195px;" title="4. The pool needed to be 26 ft. deep in order to provide enough clearance for this ship structure to appear magically from below the water level." />To coordinate the motion of the multiple axes operating each panel, the controls engineering team set up the motion controllers to use a special synchronization function that allows some or all of the axes that the motion controllers to be configured as slave axes, under the control of a master axis or a master input coming from an outside control source. In the Dancing Water system, the motion of each lift cylinder is tightly controlled by an RMC as a slave axis following commands from a master PLC.&nbsp;</p> <h3>Feedback of Linear Position</h3> <p>The motion controllers receive cylinder position feedback from the magnetostrictive linear displacement transducers (LDTs) that are mounted inverted alongside the cylinder bodies, with the controls on the rod side and the sensing probe extending down toward the cap of the cylinder.&nbsp;This orientation allows easier removal and repair or replacement than if they were mounted inside the cylinders.&nbsp;A stainless-steel rod and magnet carrier is attached to the cylinder&rsquo;s rod clevis that carries the magnet up and down the sensing element of the probe pressure tube. The LDTs, each situated in a watertight housing, interface to the RMCs in the dry area under the pool via synchronous serial interface using waterproof cabling, seal glands, and connectors.</p> <p><img alt="Fig. 5" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/DeltaFig5LinearTransducers.gif" style="margin: 5px; float: left; width: 420px; height: 308px;" title="5. The Dancing Waters application uses 11 RMC150 motion controllers with Ethernet communications to the PLC. " />Another interesting aspect of the magnetostrictive LDTs was pointed out by Mike Wardle of MTS Sensors Division. He said the maximum length for the standard rigid sensor, in general, is 300 in. (25 ft.). So the 27-ft. requirement for this application demanded an alternative. Wardle said the standard maximum length for a flexible sensor is 10 m&mdash;32.8 ft. This meant a standard flexible sensor could be used and held rigid inside the watertight enclosure. Additionally, these flexible sensors are easily coiled, packaged, and shipped more cost effectively.</p> <p>The flexibility and smooth motion enabled by the motion controllers far exceeded the expectations of the show&rsquo;s production staff. &ldquo;Initially, the staff was hoping to be able to position the stages in some simple configurations, but they learned that through the precision and programmability of the hydraulic controls more special effects were possible,&rdquo; says Comoso&rsquo;s Schoenbachler. &ldquo;We believe that our system gave Franco Dragone the capability to produce more dynamic moves in making an even more spectacular show.&rdquo; And as an indicator of the robustness of the hydraulic system, The House of Dancing Water show has been delighting audiences for more than five years.</p> <p>Take a behind-the-scenes look at the staging:</p> <p><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/uO1PqsjRfhY" width="560"></iframe></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/controlling-biggest-water-show-earth-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> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/controls-instrumentation/controlling-biggest-water-show-earth#comments Controls & Instrumentation Thu, 05 May 2016 15:35:00 +0000 38201 at http://hydraulicspneumatics.com Controlling the Biggest Water Show on Earth (.PDF Download) http://hydraulicspneumatics.com/datasheet/controlling-biggest-water-show-earth-pdf-download <div class="node-body datasheet-body"><p>Taking in Franco Dragone&rsquo;s <em>The House of Dancing Water</em> production in Macau, China&rsquo;s City of Dreams, is breathtaking. Sophisticated staging is actually composed of eight different lift sections. The stage sits atop a forest of hydraulic cylinders...</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> <div class="og_rss_groups"></div> Thu, 05 May 2016 14:58:00 +0000 38231 at http://hydraulicspneumatics.com Thermal Analysis of a Garbage Truck’s Hydraulics http://hydraulicspneumatics.com/waste-management/thermal-analysis-garbage-truck-s-hydraulics <div class="field-byline"> Peter Weller, P.E. </div> <div class="field-deck"> What happens when a hydraulic system operates with fluid temperature that exceeds the normally recommended maximum of 180° F? A model was developed to study thermodynamic behavior of a hydraulic system in a garbage truck that can also be applied to hydraulic systems on other work trucks. </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/thermal-analysis-garbage-truck-s-hydraulics-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/Lead.jpg" style="width: 595px; height: 446px;" /></p> <p>A characteristic sometimes overlooked with hydraulic systems on industrial trucks, such as garbage trucks, is what happens when&nbsp; they operate at high fluid temperature.&nbsp; High fluid temperature can degrade the fluid, cause premature failure of components, rob system performance, and even pose safety hazards to personnel.&nbsp;</p> <p>A finite-difference model for a typical garbage-truck hydraulic system was derived to predict these temperatures. Actual weather data for a sea-level southwestern American city in mid-summer were used as input parameters for the model to represent actual worst-case conditions. This model considered pressure losses in the hydraulic system from viscous effects and friction during operation. These losses increase internal energy of the fluid, resulting in higher fluid temperature. The model also incorporates calculation of heat transfer to and from the hydraulic system. The system receives solar radiation and expels heat by convection to the ambient air.&nbsp;</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/hydraulic-fluids/hydraulic-fluids-meet-tighter-requirements-marine-vessels">Hydraulic Fluids Meet Tighter Requirements for Marine Vessels</a></p> <p><a href="http://hydraulicspneumatics.com/blog/how-cool-hot-hydraulic-system">How To Cool A Hot Hydraulic System</a></p> <p><a href="http://hydraulicspneumatics.com/controls-instrumentation/multi-domain-modeling-and-simulation-intended-fluid-power">Multi-Domain Modeling and Simulation Intended for Fluid Power</a></p> </div> <p>The model predicts fluid temperatures of up to 300&deg; F during normal operation of each truck on a day when the ambient air temperature reaches 115&deg;F. The 300&deg;F temperature produced by a garbage truck under such conditions significantly exceeds the maximum recommendation of 180&deg;F for hydraulic fluid. The conservative model also tends to underestimate pressure loss and thermal parameters that predict fluid temperatures. <em>Actual fluid temperatures for the given meteorological parameters will be higher than those in the model output.&nbsp; </em></p> <p><strong>Building the Algorithm</strong></p> <p>The algorithm in the model was based on the first law of thermodynamics, which states that the heat transferred to a system equals the sum of the increase in internal energy of the system and the work done by the system. If we consider hydraulic fluid to be incompressible, its specific heat is well documented.&nbsp; The product of the fluid&rsquo;s specific heat and the increase in its temperature yields the increased internal energy of an incompressible fluid. Therefore, we can calculate fluid temperature if we know the initial fluid temperature and the temperature change, which is determined by evaluating the heat transferred to or from the system and the work done by or on the system.&nbsp;</p> <p>Heat transfer evaluated by the model includes solar radiation into the hydraulic system and convection of heat from the system to the ambient air.&nbsp; Solar radiation data were obtained from a state meteorological database for a day when the ambient temperature reached almost 115&deg;F.&nbsp; These data give the amount of solar energy incident on a horizontal surface by hour of the day. We estimated that the hydraulic system absorbs 80% of incident radiation, based on documented emissivities of similar materials.&nbsp;</p> <p>Both free convection and forced convection were evaluated as mechanisms for transferring heat from the hydraulic system to the air. Free convection is a process in which molecules of a fluid (ambient air in this analysis) in contact with a warmer body absorb heat, become buoyant, and are displaced by molecules with less internal energy.&nbsp; For the sake of simplicity, we assumed that no temperature gradient exists between the hydraulic fluid and the ambient air and that the wall temperature matches that of the hydraulic fluid.&nbsp;</p> <p>In reality, the walls of hydraulic reservoirs, hoses, and other components tend to absorb heat from the fluid. Therefore, wall temperatures are actually lower than the fluid&rsquo;s, creating an insulating effect. The heat transfer rate varies directly with the difference between the wall temperature and the temperature of the air, so the actual heat transfer rate from the fluid to the ambient air by free convection will be less than that estimated by the conservative model.</p> <p><strong>More on Convection</strong></p> <p>Forced convection occurs when a fluid (ambient air) is directed at some non-zero velocity against a warm surface.&nbsp; Heat is transferred by a combination of buoyant effects and momentum as energy from the warm surface by conduction to molecules of air. These molecules are then replaced by other molecules lower in internal energy. Wind promotes forced convection. Meteorological data for a sea-level southwestern U.S. city were inspected, and it was found that the maximum wind speed for many days stayed less than 8 mph during the hours of operation for the packer trucks.&nbsp;</p> <p>In keeping with a conservative approach, we assumed that the wind blew directly across the hydraulic system and reservoir in the direction most beneficial for cooling the system. Furthermore, the outer wall of the reservoir is partially exposed to ambient air as the truck is driven. An average effective wind speed of 12.5 mph (relative to the reservoir) was calculated, based on the estimated truck speed and portion of the day during which the truck was moving. Forced convection of heat from this surface was calculated based on the higher effective wind speed. Because the rate of heat transfer varies directly with wind speed, these choices for wind speed values are conservative.&nbsp; As in the free convection analysis, wall temperatures were equated with hydraulic fluid temperature.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Finite-difference-table.gif" style="width: 595px; height: 377px;" /></p> <p>Pure conduction of heat from the hydraulic system and reservoir to another solid body was not considered a significant mechanism for cooling because the contact areas are small and because other nearby bodies are also heat sources (the truck engine and exhaust).&nbsp; Conduction between solid bodies is proportional to the contact area and the temperature difference. Radiation and convection of heat from the road surface to the hydraulic system and reservoir also were not considered because of the difficulty in describing these mechanisms mathematically and because assuming them to be negligible is conservative.&nbsp;</p> <p><strong>Components of the Hydraulic System</strong></p> <p>The hydraulic pump in these trucks is driven through a power takeoff (PTO). The difference between the input power from the PTO and the work performed by the hydraulic cylinders becomes pressure losses as the hydraulic fluid flows through the circuits. Empirical data relating pressure loss to fluid flow rate for different types of hose and tube are available in the literature.</p> <p>Hose sizes were taken from the specifications for an actual side-load compactor truck, and pressure losses were obtained from these data. Pressure losses for pipe and standard fittings (elbows, tees, sudden expansions, sudden contractions) are related to fluid velocity, density, and viscosity and are proportional to empirical factors reported in literature. The sizes of pipe and fittings were obtained from drawings, and losses were tabulated after calculations were made using this information.&nbsp;</p> <p>Pressure losses through filters, hydraulic control valves valves were obtained from the actual manufacturers&rsquo;&nbsp; technical catalogs for each model. Properties of a typical hydraulic fluid recommended for use in such climates (Texaco Rando HD46) were obtained from literature published by Texaco for that fluid. &nbsp;</p> <p><strong>Setting up the Analysis</strong></p> <p>Perfect data cannot be obtained for any analysis.&nbsp; In cases in which directly applicable data for refuse truck specifications, drawings were not available, or calculation of input parameters or data was not straightforward, we made assumptions that could be reasonably supported. When no reasonable assumption could be made, data that would lead to higher predicted fluid temperatures were not used, in order that the analysis remain conservative.&nbsp;</p> <p>We assumed that the packer trucks operate on a 10-hour daily shift. The actual time each truck is collecting (and, therefore, operating the hydraulic system&rsquo;s boom and pack circuits) is approximately six hours per day. The pack circuit is continuously operating while the truck is collecting, then is turned off when the truck is driven to and from a landfill, transfer station, or fleet garage.&nbsp;</p> <p>The boom operates intermittently while the truck is loading cans at a house. It is then inactive when the truck is driven between houses. Based on discussion with waste management personnel, it was determined that each truck collects solid waste from 1,200 to 1,300 houses per day. Using these parameters, duty cycles were evaluated for the boom and pack circuits and were applied by the model to the calculation of pressure losses because no pressure losses occur when the hydraulic system is not actuated. However, heat transfer occurs continuously.&nbsp;</p> <p>For much of the time, the pack circuit is actuated, but the boom circuit is not.&nbsp; During these times, the model calculates no losses for the boom circuit.&nbsp; However, hydraulic fluid is still flowing through the control valve for the boom circuit and back to the reservoir, although no fluid flows through the work port on the control valve. In reality, though, some pressure loss from this flow still occurs when only the pack circuit is actuated. Omitting this loss tends to underestimate fluid temperatures and is conservative.&nbsp;</p> <p><strong>Examining the Results</strong></p> <p>The finite difference model was run for three cycle times: 8, 10, and 14 seconds. Actual cycle times usually range from 10 to 14 seconds. The <em>table</em> above shows detailed results for the 8-sec cycle, whereas the <em>graph</em> below summarizes fluid temperatures during the day for a 10-sec cycle. The analyses account for the normal activities of the truck and operators during a typical shift,&nbsp; including driving to pickup sites and back to the collection yard, collecting refuse in residential neighborhoods, break times, lunch time, and refuse dumping.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/FluidTemp-TimeDay.png" style="width: 596px; height: 373px;" title="This graph plots hydraulic fluid temperature for a 10-sec cycle time. Similar trends resulted with 8- and 14-sec cycle times." /></p> <p>This scenario of activities is proposed as typical based on our experience for daily collection operations. It undoubtedly varies from day to day and from truck to truck.&nbsp; We don&rsquo;t expect these variations would alter the conclusions for this analysis. Solar radiation as energy incident on a horizontal surface per unit time was obtained for a southwestern U.S. city for the subject day and is shown on the table.</p> <p>The time increments shown generally conform to the operational activities for the truck, except in the early hours, where time increments were reduced to promote accuracy in exercising the model. During this early period, the thermal dynamics of the system are changing rapidly because the hydraulic system is starting to transfer energy to the fluid, and more data points are needed.</p> <p>The columns labeled <em>Pack loss</em> and <em>Boom loss</em> represent the energy put into the fluid by the&nbsp; pressure drops in the pack-eject and boom circuits, respectively. The columns labeled <em>Q-HS</em> and <em>Q-Res</em> are the total rates of heat transfer from the hydraulic system (excluding the reservoir) and the reservoir, respectively, for all heat transfer mechanisms&mdash;solar radiation, free convection, and forced convection.</p> <p>The last two columns show the change in fluid temperature from the last time period and the fluid temperature for the indicated time period, respectively.&nbsp; The model calculates the change in temperature due to the energy input to the fluid, less the heat energy transferred from the fluid, during the prior time period and adds the temperature difference to the fluid temperature for the last time period to obtain the value shown.</p> <p>The table shows that the temperature of the modeled fluid exceeds 180&deg;F early in the day. Operator breaks and down time at the dump/transfer station promotes cooling because convection removes heat from the hydraulic system and no pressure losses are produced.&nbsp; However, internal energy is generated at such a high rate from pressure losses in the system during operation that the fluid remains at excessive temperatures for almost the entire day because the heat transfer rate from the fluid is insufficient for cooling it.&nbsp;</p> <p><strong>Effect of Heat on Seals</strong></p> <p>Standard seal materials for normal industrial applications have maximum allowable temperatures to 250 or 300&deg; F, depending on the actual compound. For most of these, temperatures from 250 to 300&deg; F are allowable for only brief periods. For Buna-S, the temperature range goes to 225&deg;F. (Higher-cost Viton seals can sometimes be specified for hydraulic components, but the maximum temperature for Viton is only 250&deg;F.)&nbsp;</p> <p>This analysis indicates that fluid temperatures higher than 300&deg; F can be expected on hot days in such climates. This means that seals in the hydraulic components should be expected to soften during operation of the packer trucks.&nbsp; As the seals soften, they will tend to extrude into the space between the parts they are sealing and, eventually, break.&nbsp; Hydraulic fluid would begin leaking when the seal extrudes, and possibly catastrophic leaks would likely occur when a seal breaks.</p> <p>However, the deleterious effects of high temperature degrade more than just seals. It also degrades the hydraulic fluid. Data for Texaco Rando HD 46 were used as a typical fluid for use in such hydraulic systems. Texaco&rsquo;s literature for this fluid shows properties up to a maximum temperature of 180&deg;F. Literature for similar fluids of the same grade indicate operating ranges for No. 46 grade fluid of 32&deg; to 160&deg;F.</p> <p><a href="http://sourceesb.com/manufacturers/search?q=parker+hannifin" target="_blank">Parker Hannifin Corp.</a> recommends a maximum reservoir fluid temperature of 145&deg;F. Higher temperatures can produce oxidation products (varnish), which can clog orifices, corrode metal surfaces, form sludge, and cause rapid wear of metal parts.</p> <p><em>Peter J. Weller, P.E., is a consulting mechanical engineer providing engineering and design services to industry and expert testimony services. For more information, visit <a href="http://www.peterjweller.com" target="_blank">www.peterjweller.com</a>. </em></p> <p><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/waste-management/thermal-analysis-garbage-truck-s-hydraulics#comments Hydraulic Pumps & Motors Rail, Truck & Bus Waste Management Thu, 05 May 2016 13:22:00 +0000 38211 at http://hydraulicspneumatics.com Give Automation a Lift with Vacuum Systems http://hydraulicspneumatics.com/vacuum-technology/give-automation-lift-vacuum-systems <div class="field-deck"> When choosing a method of power for picking, holding, and automation applications, it would be a mistake not to consider vacuum. </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/give-automation-lift-vacuum-systems-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>As compressed air does, vacuum puts the atmosphere to work. In a compressed air system, increased air pressure creates the work force. In a vacuum system, air pressure is reduced to a level lower than atmospheric pressure; then the higher pressure in the surrounding atmosphere creates the work force.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/vacuum-technology/getting-out-pickle-vacuum-technology">Getting Out of a Pickle with Vacuum Technology</a></p> <p><a href="http://hydraulicspneumatics.com/vacuum-technology/vacuum-systems-intelligent-factory">Vacuum Systems for the Intelligent Factory</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-simple-and-efficient">Hydraulic-Electric Analogies: Simple and Efficient</a></p> </div> <p>Pressure is reduced by evacuating a portion of the air from a closed volume. Doing so produces a pressure differential. In a sense, the volume available to molecules has increased. And the laws of physics state that when volume increases, pressure decreases.</p> <p>In an industrial vacuum system, the closed container can be a work device, valve, or actuator. A vacuum pump removes air from the system to create a pressure differential.</p> <h3>Mechanical Vacuum Pumps&nbsp;</h3> <p>The two different types of vacuum pumps are commonly used for automation (pick-and-place applications): positive-displacement mechanical pumps and compressed air-powered vacuum generators (also known as Venturi pumps or ejector pumps).</p> <p>A mechanical vacuum pump may be thought of as a compressor that operates with its intake below atmospheric pressure and the discharge at atmospheric pressure. Compressors and vacuum pumps have identical pumping mechanisms. The vacuum pump is simply piped to withdraw air from a closed container and exhaust to atmosphere, which is just the opposite of what a compressor does.</p> <p><img alt="Fig. 1" height="290" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Gast-vacuum-pump.jpg" style="margin: 5px; float: right;" title="This two-cylinder, piston-type vacuum pump is mounted to a tank to reduce the cycling rate of the pump holding vacuum in reserve. (Courtesy of Gast Mfg.)" width="340" />Mechanical vacuum pumps draw a relatively constant volume of air despite any variation in the vacuum level and can pull a relatively high vacuum. The principle types of mechanical pumps include: reciprocating and rocking piston, rotary vane, diaphragm, lobed rotor, and rotary screw designs.</p> <p>Although compressors and vacuum pumps have many similarities, two significant differences between compression and vacuum pumping actions must be considered in system design. The maximum change in pressure produced by a vacuum pump is limited; it can never be higher than atmospheric pressure. Plus, as vacuum level increases, the volume of air passing through the pump drops continuously. Therefore, the pump itself finally must absorb virtually all heat generated.</p> <p>This means temperature is an important consideration when selecting a mechanical vacuum pump because high external or internal heat can greatly affect pump performance and service life. Internal pump temperature is important because as vacuum level increases, less air is present to carry away the heat generated, so the pump must absorb more of the heat.</p> <h3>Vacuum Generators</h3> <p>Vacuum generators are powered by pressurized gas, usually compressed air. The compressed air flows into the ejector pump and expands in one or more ejector nozzles. When expanding the stored energy (pressure and heat), it is then converted into kinetic energy. The speed of the compressed air jet increases rapidly, while the pressure and the temperature decrease, attracting more air and thereby creating a vacuum on the suction side.</p> <p>Two types of vacuum generators are generally used for pick-and-place applications: single, and multi-stage generators. Single-stage unit pumps are compact and emit no heat, but are noisy, provide either high-flow/low-vacuum or low-flow/high-vacuum performance, and consume considerable compressed-air energy in their operation.</p> <p><img alt="Fig. 2" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Parker-CHF-two-stage.jpg" style="width: 300px; height: 300px; margin: 5px; float: left;" title="This two-stage vacuum generator offers several performance advantages over its less-expensive, single-stage counterpart. (Courtesy of Parker Hannifin Pneumatic Div.)" />Multi-stage generators are much quieter, emit little or no heat, and operate more efficiently than single-stage units. However, multi-stage units cost more than their single-stage counterparts and are not as compact.</p> <h3>Choosing a Vacuum Pump&nbsp;</h3> <p>You must consider the vacuum level, vacuum flow, and the ratio between them (pump characteristics) when choosing the correct pump type for a specific application. The <em>effect factor</em> aids in the selection of vacuum pumps. The effect&nbsp; factor is the product of flow (suctioned air quantity) and vacuum level.</p> <p>The effect factor of several pumps is shown in the illustration. Vacuum level is on the horizontal scale and effect factor on the vertical scale. The plots indicate which type of pump is the most effective at a certain vacuum level. The maximum <em>suction effect</em> is achieved at the highest value of the effect factor. If power consumption is constant, the highest efficiency is reached at the same point.</p> <p><img alt="Fig. 3" height="347" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/VacuumEffectGRAPH.gif" style="margin: 5px; float: right;" title="This graph indicates which pump type is the most effective at specific vacuum level." width="420" />A vacuum generator has constant power consumption at a constant feed pressure, whereas the power consumption varies with the load for mechanical pumps. For sealed systems, the capacity of the pump is determined by how fast the system can be evacuated to a certain vacuum level. This capacity is called the <em>evacuation time</em> of the pump and is normally specified in standard cubic feet per minute (scfm). This value is multiplied by the volume of the system in order to obtain the evacuation time to achieve the desired vacuum level.</p> <p>The case is different with non-sealed systems such as lifting a work piece having a porous surface. To maintain the desired vacuum level, the pump must have the capacity to pump away the air leaking in. By establishing the leakage flow, it is possible, by reading the pump data, to find the right pump for a specific application.</p> <p>If the leakage occurs through a known aperture, the flow can be established. When the leakage occurs through a porous material or in an unknown way, the flow can be established by a test with a vacuum pump. The pump is connected to the system and the obtained vacuum level is read.</p> <h3>Vacuum Cups&nbsp;<strong> </strong></h3> <p>Vacuum (suction) cups can lift, move, and hold objects from just a few ounces to several hundred pounds. A vacuum cup adheres to a surface because the surrounding atmospheric pressure is higher than the pressure between the vacuum cup and work piece surface. The cup is connected to a vacuum pump through hose or tubing to create the low pressure. The lower the pressure (higher the vacuum), the greater the force on the suction cup.</p> <p>The required lifting force is the critical consideration when sizing a suction cup. To determine the right size, use the simple equation for force: <em>F</em>&nbsp; = <em>P</em> &times; <em>A</em>.</p> <p>Because the weight of the object being handled is often known, and the diameter (area) of the suction cup is required, a simplified equation for rough estimates can be used. Consideration should also be given to the safety factor (often two) and the number of suction cups.</p> <p>D&nbsp; = 1.64 (m &times;&nbsp; n)<sup>1/2</sup> <strong>/ </strong>(U &times; s)<sup>1/2</sup> &nbsp;</p> <p>where D = diameter of suction cup, in.</p> <p>m = mass, lb,</p> <p>n = safety factor, and</p> <p>U = vacuum, in. Hg, and</p> <p>s = number of suction cups.</p> <p>High levels of vacuum for vacuum cups should be avoided. A deep vacuum means that the pump must work more, and wear on the suction cup increases accordingly. For example, increasing the vacuum level from 18 in. Hg to 27 in. Hg, the force increases by 1.5. However, 10 times as much energy is needed to achieve this 50% increase in lifting force. Therefore, using a lower vacuum level with a larger surface area is generally preferable to using smaller cups at higher vacuum.</p> <h3><img alt="Fig. 4" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/05/Schmalz.jpg" style="width: 300px; height: 200px; margin: 5px; float: left;" title="Vacuum cups come in a wide variety of sizes, shapes, configurations, and materials of construction, some designed for specific applications. Here, the vacuum circuit is designed for handling semi-porous corrugated cardboard, and the vacuum pad is made of a wear-resistant material with a structure that provides stability in accommodating lateral loads. (Courtesy of Schmalz Inc.)" />Types of Vacuum Cups&nbsp;<strong> </strong></h3> <p>A variety of suction cup types is available that covers virtually all applications. The following are types of cups with brief descriptions:</p> <p><strong>Universal suction cup</strong>&mdash;a simple design for handling objects with a flat or slightly curved surface.</p> <p><strong>Suction cup with short bellows</strong>&mdash;suitable when level adjustment is required. Several short bellows in one lifting device can handle objects with height differences and varying shapes. The bellows also provides a slight lifting movement that can be used to separate thin items. However, it is poorly suited to vertical lifting.</p> <p><strong>Suction cup with long bellows</strong>&mdash;the same applications as for short bellows, but the long bellows can cope with greater differences in levels and provides a longer lifting movement. It is not suitable for deep vacuum and can be equipped with reinforcement rings of polyamide to give extra stability</p> <p><strong>Deep suction cup</strong>&mdash;used for curved and irregular surfaces. It can even lift around corners and edges and generally is not suitable for use on flat surfaces. &nbsp;</p> <p><strong>Flat suction cup with cleats</strong>&mdash;suitable for flat objects such as cardboard, sheet metal, and porous materials. The cleats stop the object from being deformed from being sucked into the cup. This cup also provides good stability because it produces very little movement.</p> <p><strong>Flat suction cup with valve</strong>&mdash;when several cups are connected together in a single system, the system can be disrupted if a suction cup leaks or misses the object to be lifted. To avoid this, each suction cup can be provided with a valve that opens only when the suction cup is pressed against the object. This feature increases safety and reduces air consumption &nbsp;</p> <p><strong>Suction cup with cellular rubber sealing</strong>&mdash;suitable for uneven and rough surfaces, such as blocks of stone or concrete and channeled plate. They are available in different shapes and sizes&mdash;round, oval, square, long, and narrow&mdash;depending on the object to be handled.</p> <p><strong>Suction cup with minimum movement</strong>&mdash;particularly suited for thin materials such as paper and plastic film. Inside the sealing strip, the suction cup has an adjustable brace that can be set so that the object is lifted completely flat without risk of deformation. Minimal movement makes these cups suitable for applications requiring accurate positioning.</p> <p>The material of a suction cup is chosen according to its application with regard to standards of oil resistance, temperature range, durability, and other factors. The most typical materials are silicone, nitrile, and chloroprene. Nitrile provides good durability, plastics have good oil resistance, silicone exhibits resistance to very high and low temperatures, and chloroprene offers high durability but poor oil resistance. Special grades are also available that can meet most requirements.</p> <h3>Fittings, Hose, and Tubing</h3> <p>Fittings often are considered a commodity, but leak-free performance and size are especially important with vacuum applications. The simplest vacuum cup has a plastic fitting so the cup can easily be changed. The fitting is adequate for handling lighter objects that do not give rise to bending stress in the suction cup. However, these fittings are not suitable for applications with high temperatures or oils.</p> <p>Often a vacuum hose diameter that is too small is chosen in an effort to reduce the volume to be evacuated. The strategy is that less volume to be evacuated equates to quicker evacuation time. What is not taken into consideration in this case is the restriction or limitation of flow that often results. In a typical vacuum application with the right size pump, using &frac14; -in. ID hose can make the application slower than using &frac12; -in. ID hose.</p> <p>A second factor to consider is the type of hose or tubing being used. It is best to use a product that is vacuum rated. Thin polyurethane tubing should not be used because heat&mdash;even room temperature&mdash;can cause it to collapse under vacuum, restricting flow. If the application permits the use of tubing, it should be sized so that the vacuum reading is zero when the cups or system is open to atmosphere.</p> <p>By restricting the vacuum flow through the hose, the entire system is limited. One of the most common problems in system design is improper sizing of the vacuum hose, tubing, or the manifold to which the hose is connected. Unfortunately, the pump is blamed in most cases for system failure, and a larger or different-type pump is installed, resulting in increased costs and energy consumption with no significant improvement in performance.</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/give-automation-lift-vacuum-systems-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> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/vacuum-technology/give-automation-lift-vacuum-systems#comments Vacuum Technology Wed, 04 May 2016 19:04:00 +0000 38141 at http://hydraulicspneumatics.com Hydraulic-Electric Analogies: Part 2—Adding a Variable to Positive Displacement http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-part-2-adding-variable-positive-displacement <div class="field-deck"> Vane pumps are like the gear pumps described in last month’s issue in their capacity to produce positive displacement, but they go one step further with variable-displacement capability. </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/hydraulic-electric-analogies-part-2-adding-variable-positive-displacement-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/MotionControl-2.png" style="width: 596px; height: 563px;" title="2. The stationary body parts consist of the ports that carry fluid into and out of the pump, and provide a sealed housing to capture internal leakage." /></p> <p>The vane pump is a positive-displacement pumping mechanism with an assembly that starts with a body containing the plumbing ports for connecting the inlet and outlet to the hydraulic system. A simplified cutaway diagram is shown in <em>Figure 2</em>. Four internal kidney-shaped ports are arranged in inner and outer configurations.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-simple-and-efficient">Hydraulic-Electric Analogies: Simple and Efficient</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-hydraulic-power-conversion-part-4">Hydraulic-Electric Analogies: Hydraulic Power Conversion, Part 4</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-hydraulic-power-conversion-part-3">Hydraulic-Electric Analogies: Hydraulic Power Conversion, Part 3</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-hydraulic-power-conversion-part-2">Hydraulic-Electric Analogies: Hydraulic Power Conversion, Part 2</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-hydraulic-power-conversion-part-1">Hydraulic-Electric Analogies: Hydraulic Power Conversion, Part 1</a></p> </div> <p>The two outer ports, which transfer the majority of fluid from the inlet to the outlet, are necessarily the larger pair. The inner ports carry the respective pressures of the outlet and inlet ports to the undersides of the sliding vanes and contribute a small amount of pumping action. Their main purpose is to apply some pressure on the underside of vanes to force them into the cam ring, thereby forming a seal between the inlet and outlet ports. Internal flow paths are machined or cast into the body so that all of the yellow areas have essentially the same pressure, whereas all aqua areas are at the inlet pressure.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MotionControl-3.png" style="width: 596px; height: 795px;" title="3. Inserting a vane into each rotor slot builds the rotating group of a vane pump." /></p> <p>The vane pump&rsquo;s moving parts consist of a slotted rotor into which rectangular vanes are inserted, one vane for each of the slots <em>(Fig. 3)</em>. Clearances between the vanes and slots are such that a compromise is made between having the vanes freely sliding within the slots and forming a fairly high impedance (low internal leakage) path between the high- and low-pressure sides. The pump design in Figure 3 has 12 vanes, but any even or odd number of vanes can be used.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MotionControl-4.png" style="width: 596px; height: 745px;" title="4. The vane pump’s rotor has all vanes in position so that the rotating group can be inserted into the cam ring." /></p> <p><em>Figure 4</em> shows all of the vanes inserted into the rotor and the rotor assembly inserted into its cam ring. The sliding fit between the rotor slots and the vanes ensures that the vanes can move outward from centrifugal force to make positive contact with the inner periphery of the cam ring. The cam ring constrains the outward (radial) motion of the vanes while the eccentricity between it and the rotor&rsquo;s center of rotation controls the pump&rsquo;s displacement.</p> <p><em>Figure 5</em> shows the full rotor assembly nested inside its cam ring. The ring is drawn at its most extreme upward position, which produces the maximum amount of eccentricity between the rotor&rsquo;s spin center and the cam-ring center and results in maximum pump displacement.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MotionControl-5.png" style="width: 596px; height: 704px;" title="5. When the rotor assembly is nested inside the cam ring, the ring constrains the outward vane motion while the relative up and down sliding of the ring controls the pump displacement." /></p> <p><strong>The Moving Parts</strong></p> <p>The vane pump has three groups of moving parts in the vane pump. First, the rotor spins about the shaft center line. Second, the cam ring moves up and down to control the displacement. Third, the vanes undergo both sliding and rotating motion. Note that the cam ring does not rotate; it can only move up and down. The assembly consisting of the rotating group and the cam ring are now ready to be installed into the pump body, getting a step closer to a functioning pump.</p> <p>Pumping action can be visualized with the aid of the body and rotating group, partially depicted in <em>Figure 6</em>. It all takes place in the volumes bounded by the rotor, the cam ring, and a pair of consecutive vanes. With the rotor spinning as indicated, look at the pair of vanes near bottom dead center, where the rotor is almost touching the cam ring. The volume trapped in the chamber between the vanes is nearly zero.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Fig-6_web.jpg" style="width: 595px; height: 685px;" title="6. The rotating group and cam ring are inserted into the pump body, and again, the eccentricity of the shaft and cam ring are apparent. The pumping chambers (the circular trapezoids bounded by the rotor, cam ring, and consecutive vanes) absorb the inlet fluid and expel the outlet fluid." /></p> <p>However, realizing that rotational motion is taking place, the volume will increase as the rotor drags the vanes along with it. The increased trapped volume reduces pressure within the expanding chamber, causing atmospheric pressure within the reservoir to push fluid into the chambers.</p> <p>Eventually, the small chamber rotates to the top position, which has the greatest trapped volume and is filled with its maximum gulp of fluid. After crossing over top dead center, the filled chamber comes into hydraulic communication with the high-pressure outlet port. Thus, the large trapped volume undergoes an extremely rapid increase in pressure.</p> <p>At that same time, the vane shown at the 12 o&rsquo;clock position forms a seal to separate the high- and low-pressure ports. Thereafter, further rotation causes the volume to decrease in the chamber, and the rotor-to-vane coordinated motion, relative to the stationary cam ring, pushes the high-pressure fluid through its kidney port (yellow) and out to the hydraulic system.</p> <p>The kidney ports are arranged so that all of the chambers on the left half of the rotor are at high pressure, while those on the left half are at low inlet pressure. With counter-clockwise rotation, as indicated in Figure 6, the right-hand external port is the pump inlet while the left-side port is the outlet.</p> <p><strong>Dealing with Leakage</strong></p> <p>Sealing between the high- and low-pressure sides is imperfect&mdash;and important. Internal leakage can make its way from the high-pressure side to the low-pressure side via several paths: An imperfect seal exists at the vane tip, as does clearance at the sides of the vanes, requiring a close fit in the axial direction between the rotor, vanes, and the stationary parts. Some small amount of leakage makes its way between and around the vanes and their slots through the clearance that&rsquo;s needed between the ends of the rotor body and the stationary mating parts.</p> <p>Much of this internal leakage finds its way into the pump body (commonly referred to as the case), shown in pale green in Figure 6. In that pump body, it must leak back into the low-pressure port to be recirculated into the pumping chambers. Thus, the pump body can reach internal pressures that approach the supply pressure.</p> <p>Containing the pressurized fluid in the body requires the use of a high-pressure dynamic shaft seal. In many pump designs, a third hydraulic port is created that carries the internal leakage back to the reservoir. This greatly reduces the internal pressure and lowers the demands on the shaft seal. Modern sealing technology can eliminate external leakage from hydraulic machines if the system is properly maintained.</p> <p><strong>Taking a Position</strong></p> <p>The pumping elements in Figure 6 are shown in the maximum displacement position. The cam ring has been positioned in its maximum up position, resulting in the maximum eccentricity between the center of rotor rotation and the center of the cam ring.</p> <p>If the rotor and cam ring are perfectly concentric, the displacement will be zero. If the cam ring is dropped below the concentric point, the inlet and outlet ports will be reversed, and so will the output flow without changing the direction of shaft rotation. Such pumps are variable displacement, and said to be capable of <em>over-center operation</em>, meaning the displacement can take on either positive or negative values.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MotionControl-7.png" style="width: 596px; height: 763px;" title="7. Stroking pistons plus external access through hydraulic ports allow the cam ring and displacement to be varied." /></p> <p>Now, though, the need arises for some external means of changing the cam-ring position so that pump output can be changed at will, or changed automatically using feedback. The stroking pistons shown in <em>Figure 7</em> provide that capability.</p> <p>External ports allow hydraulic access to the pistons, usually with an electrohydraulic servo or proportional valve. Electrohydraulic stroking is done by closing the loop on the cam-ring position with a position transducer, most often with a linear variable differential transformer (LVDT), not shown in Figure 7. Cam-ring guides (dark green) prevent its right-left movement.</p> <p>Pressure compensation in the variable-displacement pump is easily achieved via hydraulic methods. Pressure compensation equips the pump with internal feedback that automatically reduces displacement if a threshold pressure is exceeded.</p> <p>In fact, pressure-compensation pumps can be safely deadheaded; that is, the output port can be totally blocked without damaging the pump. One way to achieve pressure compensation of the vane pump is shown in <em>Figure 8</em>.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MotionControl-8.png" style="width: 596px; height: 763px;" title="8. Pressure compensation can be achieved by connecting the stroking piston port to the outlet pressure and replacing the lower stroking piston with an adjustable bias spring. " /></p> <p>Here, the lower stroking piston has been replaced by a bias spring with a pre-compression adjusting screw. The upper stroking piston&rsquo;s hydraulic port is connected to the outlet pressure so that the piston &ldquo;senses&rdquo; the outlet pressure. The bias-spring pre-compression causes an upward force on the cam ring, forcing the cam ring into the position shown when the outlet pressure is low. Under this operating condition, the pump operates like a fixed-displacement pump at max displacement and max output flow.</p> <p>As the load pressure builds, the stroking piston exerts an increasing force on the top of the cam ring. At some point, the stroking piston force exceeds the pre-compression force of the spring, which automatically decreases the displacement. Blocked port pressure and deadhead pressure mean the same thing, i.e., the pressure at the outlet port under the condition of zero output flow. It is analogous to the Thevenin voltage of an electrical generator or other voltage source.</p> <p>The preceding figures on vane pumps are not necessarily depicting actual construction practice of such machines. Instead, they show the principles of operation. For example, pressure-compensated vane pumps do not use physical stroking pistons. A less-costly method is to rotate the kidney ports slightly in the direction shaft of rotation, counter-clockwise. A tremendous force acts on the inside of the cam ring at high pressures, upwards of tens of thousands of pounds in large pumps at high pressures.</p> <p>By rotating the kidneys ever so slightly, a component of force emerges in the down direction. That force is used to act against the bias spring and force the cam ring downward in the face of high outlet pressures. Therefore, no stroking piston is needed. And eliminating the stroking piston can significantly reduce the size of the pump body. Many other practical construction details exceed the scope of this brief look at electric and hydraulic analogies and principles of operation.</p> <p><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulic-electric-analogies-part-2-adding-variable-positive-displacement#comments Hydraulic Pumps & Motors Wed, 04 May 2016 19:03:00 +0000 38181 at http://hydraulicspneumatics.com Low-Speed, High-Torque Motor has Wealth of Features http://hydraulicspneumatics.com/hydraulic-pumps-motors/low-speed-high-torque-motor-has-wealth-features <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Concrete%20mixer.jpg" style="width: 261px; height: 230px; margin: 3px; float: left;" title="1. Applications requiring heavy loads to be accelerated from rest, such as this portable concrete mixer, stand to benefit from Fluidyne Fluid Power’s new 500 Series low-speed, high-torque motors." />​Geroler-type hydraulic motors have a great reputation for delivering low-speed, high-torque power. Their compact design also makes them the first or only choice when space is tight &mdash; especially because they drive loads directly without needing a speed-reducing gearbox.</p> <p>However, some designs of geroler motors exhibit internal leakage that prevents them from starting loads effectively from rest. The internal leakage allows fluid to bypass pressure chambers and some of it flow through the motor&rsquo;s case drain. The result of this bypass is reduced starting torque.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/blog/hydraulic-motor-dry-starts-and-how-avoid-them ">Hydraulic Motor &#39;Dry Starts&#39; And How To Avoid Them</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/troubleshooting-challenge-post-hole-hammer-undergoes-pump-failures">Troubleshooting Challenge: Post-Hole Hammer Undergoes Pump Failures</a></p> <p><a href="http://hydraulicspneumatics.com/blog/unusual-hydraulic-pump-problem">An Unusual Hydraulic Pump Problem</a></p> </div> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/500%20Series%202.jpg" style="width: 229px; height: 193px; margin: 3px; float: left;" title="2. Fluidyne's heavy duty 500-Series motors target low-speed, high-pressure applications. " />​Fluidyne Fluid Power, Fraser, Mich., resolves this issue with its new heavy duty 500-Series Motors. The 500-Series motors are available in 11 nominal displacements from 125 to 750 in.<sup>3</sup>/rev. (7.20 to 45.45 cc/rev.). The motors&rsquo; valve-in-rotor design efficiently distributes oil and reduces overall motor length. A pressure-compensated balance plate improves volumetric efficiency at low flow and high pressures. They feature bi-directional rotation and a high-pressure Viton shaft seal that eliminates the need for a case drain.</p> <p>Joan Armstrong, engineering manager at Fluidyne, explains, &ldquo;These motors are especially suited for low-speed, high-pressure applications with smooth rotation throughout speed transitions. The hydrostatic balance pressure plate flexes to allow for proper lubrication and high operating efficiency. Plus, the combination of shafts, mounts, and displacements let you configure these motors to almost any application&nbsp;requirements.&rdquo;</p> <p>For more information on the 500 Series motors and other products, call (586) 296-7200, or visit <a href="http://www.fluidynefp.com" target="_blank">www.fluidynefp.com</a>.</p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/hydraulic-pumps-motors/low-speed-high-torque-motor-has-wealth-features#comments Hydraulic Pumps & Motors Wed, 04 May 2016 18:47:00 +0000 38171 at http://hydraulicspneumatics.com Give Automation a Lift with Vacuum Systems (.PDF Download) http://hydraulicspneumatics.com/datasheet/give-automation-lift-vacuum-systems-pdf-download <div class="node-body datasheet-body"><p>As compressed air does, vacuum puts the atmosphere to work. In a compressed air system, increased air pressure creates...</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=38151&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> <div class="og_rss_groups"></div> Gold Wed, 04 May 2016 18:24:00 +0000 38151 at http://hydraulicspneumatics.com Los Varios Roles de los Acumuladores en un Sistema http://hydraulicspneumatics.com/blog/los-varios-roles-de-los-acumuladores-en-un-sistema <div class="node-body blog-body"><p>Los Acumuladores Hidr&aacute;ulicos almacenan energ&iacute;a mediante la compresi&oacute;n de un gas, generalmente nitr&oacute;geno. &Eacute;ste gas a alta presi&oacute;n entonces desplaza el fluido hidr&aacute;ulico a trav&eacute;s del p&oacute;rtico del acumulador cada vez que la presi&oacute;n del sistema cae por debajo de la del gas comprimido en la vejiga (diferencial). El almacenaje de energ&iacute;a potencial y la naturaleza de amortiguaci&oacute;n de un&nbsp;gas comprimido tambi&eacute;n convierten a los acumuladores en fuente &uacute;til para reducir comportamientos din&aacute;micos no&nbsp;deseados&nbsp;en un sistema hidr&aacute;ulico.</p> <p>Entre las funciones que puede cumplir un acumulador hidr&aacute;ulico en un sistema se encuentran:</p> <p><strong>Absorci&oacute;n de Pulsaciones</strong> - muchas bombas entregan caudal con pulsaciones. La bomba de pistones, com&uacute;nmente usada por su capacidad de presi&oacute;n, puede generar pulsaciones que son perjudiciales para un sistema a&nbsp;alta presi&oacute;n. Un acumulador correctamente&nbsp;ubicado en el sistema amortiguar&aacute; sustancialmente las mismas.</p> <p><strong>Amortiguaci&oacute;n de Shock o Golpe</strong>&nbsp;- si el cilindro o cualquier otro actuador de un sistema hidr&aacute;ulico se detiene repentinamente, el cambio brusco puede crear una onda de presi&oacute;n que viaja a trav&eacute;s del sistema. &Eacute;sta onda puede desarrollar picos de presi&oacute;n mucho mayores que la presi&oacute;n de trabajo del sistema. La amortiguaci&oacute;n del gas de un acumulador, correctamente ubicado en el circuito, minimizar&aacute; este shock.</p> <p><strong>Suplemento de Caudal</strong> - un acumulador puede asistir a la bomba hidr&aacute;ulica en entregar caudal al sistema. La bomba entrega caudal al acumulador, que bajo resistencia permite que se genere la presi&oacute;n requerida para cargarlo. Esta energ&iacute;a es almacenada y entregada cuando picos de potencia lo hacen necesario, lo que&nbsp;nos permite seleccionar una bomba mucho m&aacute;s peque&ntilde;a, resultando en ahorros en costo y potencia instalada.</p> <p><strong>Compensaci&oacute;n&nbsp;de Presi&oacute;n</strong> - cambios en los niveles de presi&oacute;n ocurren en un sistema hidr&aacute;ulico cuando el fluido es sujeto a cambios de&nbsp;temperatura. De igual manera, la presi&oacute;n puede caer&nbsp;como consecuencia de p&eacute;rdidas. El acumulador hidr&aacute;ulico compensa esos cambios de presi&oacute;n, ya sea entregando o recibiendo cantidades relativamente peque&ntilde;as de fluido hidr&aacute;ulico. De igual manera, si la fuente de poder falla o se detiene, el acumulador actuar&iacute;a como una fuente auxiliar de potencia, manteniendo la presi&oacute;n en el sistema.</p> <p><strong>Potencia &#39;Stand By&#39;</strong> - un acumulador puede retener gas presurizado indefinidamente y descargar la energ&iacute;a cuando se requiera. &Eacute;sto hace que los acumuladores resulten muy &uacute;tiles como una fuente de potencia latente cuando la misma se pierde desde el accionamiento principal (motor el&eacute;ctrico o di&eacute;sel). Por ejemplo, el acumulador puede actuar como una bater&iacute;a hidr&aacute;ulica para accionar el arrancador hidr&aacute;ulico de un motor.</p> <p>&nbsp;</p> </div> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/hp-en-tu-idioma">H&amp;P en tu idioma!</a></li> </ul></div> http://hydraulicspneumatics.com/blog/los-varios-roles-de-los-acumuladores-en-un-sistema#comments Accumulators H&amp;P en tu idioma! Tue, 03 May 2016 19:13:00 +0000 38131 at http://hydraulicspneumatics.com Compact Hybrid Actuation System Targets Renewable-Energy Designs http://hydraulicspneumatics.com/blog/compact-hybrid-actuation-system-targets-renewable-energy-designs <div class="node-body blog-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/HAS%20on%20the%20bakc%20of%20a%20solar%20panel.PNG" style="margin: 3px; font-size: 12.8px; line-height: 20px; width: 300px; height: 205px; float: left;" title="1. HAS features a compact design for easy installation on solar-tracking solar panels. Its hybrid design enables various stroke lengths for controlled motion, and resilience against mechanical stresses." /></p> <p>With an eye toward the renewable-energy sector, <a href="http://www.parker.com/portal/site/PARKER/menuitem.4a7ba99b3c73ae7cc39acea5427ad1ca/?vgnextoid=ab4b0f93307c7310VgnVCM10000023cc1dacRCRD&amp;vgnextchannel=26395672481c7310VgnVCM10000023cc1dacRCRD&amp;vgnextfmt=EN&amp;vgnextcat=Hydraulics+Group&amp;relatorId=ca9b0f93307c7310VgnVCM10000023cc1dac____" target="_blank">Parker Hannifin Corp.</a> unveiled a hybrid actuation system (HAS) comprised of hydraulic and electromechanical actuators for precise control and holding power. The streamlined HAS&rsquo;s hydraulic system consists of a double-acting cylinder, pump, and manifold with fluid-exchange ports (all serviceable onsite).</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/200/TechZone/SystemInstrumen/Article/False/87212/TechZone-SystemInstrumen">Motion controller renews old machine</a></p> <p><a href="http://hydraulicspneumatics.com/waste-management/parker-deliver-more-hydraulic-hybrid-refuse-truck-systems ">Parker to deliver more hydraulic hybrid refuse truck systems</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-pumps-motors/fundamentals-hydraulic-motors">Fundamentals of Hydraulic Motors</a></p> </div> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/anatomy.PNG" style="font-size: 12.8px; line-height: 20px; margin: 3px; width: 595px; height: 400px;" title="2. HAS combines hydraulic-cylinder actuation with an electric motor. " />Transfer tubes and rods are constructed out of stainless steel for corrosion protection. The system has a longer service life because internal wear items are permanently lubricated by the hydraulic fluid; it does not require external hydraulic hoses or power units. A locking mechanism, achieved via static hydraulic fluid, holds strong against mechanical stresses like wind and other impacts to further enhance the electromechanical actuation system.</p> <p>An electric motor eliminates leak paths into or out of the package. The motor, which has a low amp draw with a 50% duty cycle, integrates both ac and dc voltage supplies. Two-wire operation makes it especially easy to set up, service onsite, or relocate.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/intellinder_3_0.jpg" style="width: 300px; height: 137px; margin: 3px; float: left;" title="3. The Intellinder sensor and display can be installed along with the HAS to provide cylinder-position feedback. " />The hybrid actuator can be designed into the pitch system to move photovoltaic panels or other parts with fewer actuators and controls. In addition, the Intellinder internal sensor and user interface can be added to the actuator for continuous, end-of-stroke, and go-switch cylinder feedback.</p> <p>According to the company, the HAS features power density up to three times that of comparable electromechanical actuators. It can move over a megawatt from a single point, suiting it for large or small systems.</p> <p>The completely enclosed body of the HAS features stainless-steel construction for resilience against rain, acidity, variations in weather, and harsh environments. It has been successfully tested in solar-tracking solar panels, wind turbines, and hydroelectric dams.&nbsp;</p> </div> <div class="field-content-focus"> <span>Content Classification:&nbsp;</span> Content Goal </div> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/fluid-power-talk">Fluid Power Talk</a></li> </ul></div> http://hydraulicspneumatics.com/blog/compact-hybrid-actuation-system-targets-renewable-energy-designs#comments News Fluid Power Talk Tue, 03 May 2016 18:32:00 +0000 38121 at http://hydraulicspneumatics.com Why You Should Record All Hydraulic Oil Top-Offs http://hydraulicspneumatics.com/blog/why-you-should-record-all-hydraulic-oil-top-offs <div class="node-body blog-body"><p>According to the National Oceanic and Atmospheric Administration (NOAA), more than 700 million gallons of petroleum products enter the environment each year. Around half of which is through irresponsible and illegal disposal. But hydraulic industry experts estimate that when it comes to hydraulic oil, between 70 and 80 percent of that lost to the environment is through leaks, spills, line breakage, and adaptor failure.<br /> <br /> One of my <a href="http://www.hydraulicsupermarket.com/pro-club.html">Hydraulics Pro Club</a> members, who is a maintenance planner for a large coal mine, recently told me his mine purchased 447,000 liters of hydraulic oil last year. It&#39;s hard to believe planned hydraulic oil changes accounted for much more than a third of this volume. So where is all the rest going? I bet the coal from this mine burns better than most. And it&#39;s safe to assume hydraulic oil leaks are not the least of their problems.<br /> <br /> With this in mind, here&#39;s a question for you:<br /> <br /> <strong>Do you know how much hydraulic oil each of your machines consumes each year?</strong><br /> <br /> The only way you can know this for sure - particularly if you have more than one hydraulic machine under your supervision, is if you measure and record all top-offs. In my experience, most hydraulic equipment users don&#39;t do this. But when clients have done so at my urging, they are often shocked at how much hydraulic oil a particular machine is actually losing over a year.<br /> <br /> Yeah, I know, it&#39;s one more thing to do. But it&#39;s almost impossible to control anything you don&#39;t measure. And as the late management guru Peter Drucker once said: &quot;What gets measured, gets managed.&quot;<br /> <br /> Of course, it&#39;s not just the cost of make-up oil you need to consider. There&#39;s the environmental cost, which like carbon emissions, is not yet fully factored into - in this case - the price of a gallon of hydraulic oil. Stay tuned for this one.<br /> Then there&#39;s the cost associated with clean-up, proper disposal and the potential safety risks posed by a leaky machine. Plus, where hydraulic oil can get out, contamination can get in. And as you&#39;re reminded each time you buy a hydraulic filter element, it costs money to remove contaminants. And even more if you don&#39;t.<br /> <br /> The downtime required to fix hydraulic leaks can be an issue. But this is often just used as an excuse for laziness. And these days, there are many innovative solutions available to eliminate problem leaks. So NOW is a good time to reassess those annoying hydraulic oil leaks that &quot;aren&#39;t worth fixing&quot;?<br /> <br /> <strong>Bottom line</strong>: failing to track hydraulic oil consumption 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> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/hydraulics-work">Hydraulics At Work</a></li> </ul></div> http://hydraulicspneumatics.com/blog/why-you-should-record-all-hydraulic-oil-top-offs#comments Hydraulics At Work Tue, 03 May 2016 00:36:00 +0000 38111 at http://hydraulicspneumatics.com Inflatable-Mattress Valve Forces Inflow of Ambient Air http://hydraulicspneumatics.com/news/inflatable-mattress-valve-forces-inflow-ambient-air <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/valve.png" style="width: 300px; height: 178px; border-width: 0px; border-style: solid; margin: 3px; float: left;" />The <em>Camper SV,</em> an inflatable mattress by camping-equipment company, Thermarest, incorporates a wide-mouthed valve into its design so that it can inflate with as a little as two breaths from the camper. The design takes advantage of the Venturi principle and responds to an internal-external pressure gradient to take in significant amounts of ambient air.</p> <p>The Venturi principle preserves mass flow rate and energy: As fluid flows through an orifice at a steady rate, a sudden reduction in cross-sectional area causes velocity to increase so that mass flow rate can be preserved through a smaller hole. This increase in velocity, or kinetic energy, is accompanied by a drop in static-pressure energy so that energy is conserved.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/pneumatic-valves/certified-valves-ensure-safety-event-fault">Certified Valves Ensure Safety In the Event of a Fault</a></p> <p><a href="http://hydraulicspneumatics.com/blog/why-you-should-fix-those-annoying-oil-and-air-leaks ">Why You SHOULD Fix Those Annoying Oil And Air Leaks</a></p> <p><a href="http://hydraulicspneumatics.com/blog/one-important-fact-about-hydraulic-spool-valves">One Important Fact About Hydraulic Spool Valves</a></p> </div> <p>Thermarest&rsquo;s <em>Camper SV </em>is responsive to a person blowing into it from about 4 inches away. As the person blows toward the valve, their mouth acts as a venturi, directing air though a small orifice at high speeds and lower pressure than the external environment. As the person&rsquo;s breath fills the mattress, a pressure gradient builds up between the internal and external environments. The <em>Camper SV </em>continuously responds to this pressure gradient by pulling the higher-pressure ambient air into it until it reaches equilibrium or fills up.</p> <p>The video below is in French, but it demonstrates the capabilities of the Camper SV:&nbsp;</p> <p><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/LK3-N1oD8BM" width="560"></iframe></p> <p>Like most valves on inflatable mattresses, the Camper SV valve is unidirectional with a release mechanism that can be activated for deflation. The mattress is 3-in. thick, 77-in. long, and is offered in 25-in. wide ($120) or 30-inch wide ($150) varieties.</p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/news/inflatable-mattress-valve-forces-inflow-ambient-air#comments Pneumatic Valves News Thu, 28 Apr 2016 14:31:00 +0000 38061 at http://hydraulicspneumatics.com Advances in Magnetostrictive Technology Make Sensors Ideal for Off-Highway Machines http://hydraulicspneumatics.com/other-technologies/advances-magnetostrictive-technology-make-sensors-ideal-highway-machines <div class="field-deck"> Sponsored by MTS Sensors </div> <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/MTS_Sensors_116x100.gif" style="width: 116px; height: 100px; float: right;" />Off-highway equipment has seen a significant increase in the need for electrohydraulic automation in mobile equipment, which, in turn, requires reliable electronic feedback of cylinder position. The most popular means of meeting this need is with an in-cylinder linear displacement transducer (LDT). And although magnetostrictive technology may not have been an obvious choice for off-highway applications in the past, advances in design and technology have brought these sensors in line with the needs of off-highway equipment. More importantly, unlike other available technologies, magnetostriction provides unmatched benefits to drive the future evolution of closed-loop control systems in off-highway equipment.</p> <p>Download <em><strong>FAQs on Advances in Magnetostrictive Technology Make Sensors Ideal for Off-Highway Machines</strong></em> sponsored by <strong>MTS Sensors</strong> to get the answers.</p> <p><br /> <script type="text/javascript"> document.write('\ <iframe style="height: 550px; width: 600px" frameBorder="0" scrolling="no"\ src="http://pages.hydraulicspneumatics.com/HP_Digital_MTS_Magnetostrictive_FAQ_DC_042116?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></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/other-technologies/advances-magnetostrictive-technology-make-sensors-ideal-highway-machines#comments Design FAQs Other Technologies Cylinders & Actuators Wed, 27 Apr 2016 20:11:00 +0000 38041 at http://hydraulicspneumatics.com Hydraulic Component Repair Using Aftermarket or Non-Genuine Parts http://hydraulicspneumatics.com/blog/hydraulic-component-repair-using-aftermarket-or-non-genuine-parts <div class="node-body blog-body"><p>Repairing a hydraulic component involves reworking or replacing all of the parts necessary to return the component to &#39;as new&#39; condition--in terms of performance and expected service life. In many cases, repairing a hydraulic pump, motor, or cylinder can result in significant savings when compared with the cost of purchasing a new one.<br /> <br /> The economics of proceeding with any hydraulic repair is ultimately dependent on the cost of the repair, relative to the cost of a new component. As a rule, the more expensive the new component is in absolute dollar terms, the more likely it is that a repair will be cost effective. The cost of a hydraulic repair is determined by a number of factors including:</p> <ul> <li>The extent of wear or damage to the component.</li> <li>The facilities and expertise of the hydraulic repair shop.</li> <li>And the repair techniques employed.</li> </ul> <p>When a hydraulic component is repaired, there are usually some parts that can be successfully re-used after they have been reworked using processes such as machining, honing, lapping, grinding and hard-chrome plating. The skilled application of these techniques can reduce the number of new parts required, reducing the overall cost of the repair.<br /> <br /> And tt is sometimes possible to reduce hydraulic repair costs further, by using non-genuine or aftermarket hydraulic parts. Some aftermarket spare parts for hydraulic components originate from the same factories that supply the genuine article and are therefore of the same quality. In many cases however, aftermarket hydraulic parts originate from niche manufacturers and their quality can vary from poor to excellent.<br /> <br /> With this in mind, it is important to distinguish between a repair using aftermarket parts of known quality that will save you money, and a repair using parts of unknown quality that is likely cost you twice as much in the long-run. You can do this by asking the repair shop two questions:<br /> <br /> 1. Has the quality of the parts been proven in terms of performance and achieved service life?<br /> 2. Is the repair covered by warranty?<br /> <br /> If the aftermarket parts are of known quality and the hydraulic repair shop is prepared to back them, the decision carries minimal risk. If the repair shop hasn&#39;t used the aftermarket parts before and their quality is unknown, you need to base your decision on how much money you will save if the parts live up to expectations; what it will cost you if they don&#39;t; and whether the repair shop is willing to carry some of the risk involved in finding out!<br /> <br /> If the quality of the parts is unproven, or the repair shop is not willing to back the repair with a warranty, it&#39;s wise to think twice before proceeding. You need to make an informed decision based on the amount of money the parts will save you if they live up to expectations, versus what it will cost you if they don&#39;t. The hydraulic repair shop may be willing to share some of the risk involved in finding out, because if the parts prove to be successful, they can offer the same solution to other customers.<br /> <br /> In other words, going ahead with a hydraulic component repair using aftermarket or non-genuine parts WITHOUT careful consideration of all the issues involved 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> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/hydraulics-work">Hydraulics At Work</a></li> </ul></div> http://hydraulicspneumatics.com/blog/hydraulic-component-repair-using-aftermarket-or-non-genuine-parts#comments Hydraulics At Work Tue, 26 Apr 2016 00:41:00 +0000 38051 at http://hydraulicspneumatics.com Hydraulics & Pneumatics Products of the Week (4/25-5/2) http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulics-pneumatics-products-week-425-52 <div class="node-body gallery-body"><div>10-speed power take-offs, flow meters, and digital pressure switches comprise this week&#39;s product gallery.&nbsp;</div> <div>&nbsp;</div> <div><em>Looking for parts? &nbsp;<a href="http://sourceesb.com" target="_blank">Go to SourceESB.com</a>.</em></div> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/hydraulic-pumps-motors/hydraulics-pneumatics-products-week-425-52#comments Products Fittings & Couplings Hydraulic Pumps & Motors Other Components Mon, 25 Apr 2016 14:05:00 +0000 38031 at http://hydraulicspneumatics.com April 2016 http://hydraulicspneumatics.com/hydraulics-pneumatics/2016-04-25 <div class="node-body magazine_issue-body"></div> <fieldset class="fieldgroup group-mag-teasers"> <div class="field-mag-teaser"> <a href="/air-filters-and-frls/compressed-air-systems-rely-proper-filtration">Compressed Air Systems Rely on Proper Filtration </a> <a href="/heat-exchangers/how-select-mobile-hydraulic-heat-exchanger">How to Select a Mobile Hydraulic Heat Exchanger</a> <a href="/other-technologies/offshore-technology-conference-open-industry-professionals-students-alike">Offshore Technology Conference Open to Industry Professionals, Students Alike</a> </div> </fieldset> <fieldset class="fieldgroup group-publication-info"><legend>Publication Info</legend> </fieldset> <div class="og_rss_groups"></div> Mon, 25 Apr 2016 04:00:00 +0000 38161 at http://hydraulicspneumatics.com Hydraulics Places Pizza Pepperoni http://hydraulicspneumatics.com/blog/hydraulics-places-pizza-pepperoni <div class="node-body blog-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Blog.jpg" style="width: 266px; height: 254px; float: right; margin-left: 4px; margin-right: 4px;" />Most of us have popped a frozen pizza into a conventional or microwave oven in an effort to satisfy the munchies. But I doubt any of us ever thought of how hydraulics probably played in role in the making of frozen pizza.</p> <p>Whether you like your pizza with traditional round or French bread crust, if you take it with pepperoni, there&#39;s a good chance your last pizza went through a Peppamatic machine designed and manufactured by the Grote Co.</p> <p>Learn how Grote engineered hydraulics and electronic controls into their machines that slice and place pepperoni on pizzas faster than the eye can see and with near-perfect precision by reading the classic article. Just <a href="http://hydraulicspneumatics.com/200/IndZone/FoodProcessing/Article/False/85193/IndZone-FoodProcessing" target="_blank"><strong>click here</strong></a>.</p> </div> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/hitch-post">The Hitch Post</a></li> </ul></div> http://hydraulicspneumatics.com/blog/hydraulics-places-pizza-pepperoni#comments The Hitch Post Wed, 20 Apr 2016 18:10:00 +0000 38021 at http://hydraulicspneumatics.com The Effect of Temperature On Static Hydraulic Pressure http://hydraulicspneumatics.com/blog/effect-temperature-static-hydraulic-pressure <div class="node-body blog-body"><p>In <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=thth">The Hydraulic Troubleshooting Handbook</a> I lay out a step-by-step SYSTEM for reliable and efficient troubleshooting. But there&#39;s another prerequisite you won&#39;t find in the troubleshooter&#39;s job description: the ability to educate and convince the most ardent sceptics of your diagnosis - usually engineers with limited hydraulics knowledge. This story, sent to me by Joachim Renner, one of our members from Germany, is a great illustration:<br /> <br /> <em>&quot;Our company supplied eight double-acting hydraulic cylinders for an auxiliary function on a tunneling machine. The cylinders had the following dimensions:<br /> <br /> Piston diameter 140 mm<br /> Rod diameter 90 mm<br /> Stroke 600 mm<br /> <br /> During machine commissioning we got a complaint that none of the hydraulic cylinders were holding pressure. All cylinders had been tested prior to delivery. Despite this, it was plausible one cylinder had failed - but not all eight!<br /> <br /> All the hydraulic cylinders were removed and returned to us for debugging. Each was pressure tested first. And no defect was detected in any cylinder. So we sent them back to our client - with test reports.<br /> <br /> After a couple of days I got a call from a very angry customer. All of the hydraulic cylinders were still not tight!<br /> <br /> What could I do?<br /> <br /> I arranged to meet the client&#39;s technical people, on-site the following day.<br /> <br /> During static testing for final acceptance, the hydraulic cylinders kept failing. To demonstrate the problem, the cylinders were extended to the internal stop and pressurized to 250 bar. A decrease in static pressure could be observed on the cylinder circuit&#39;s pressure gauge. Eventually the pressure dropped to zero. All cylinders were fitted with pilot operated check valves at the cap-end port.<br /> <br /> I asked for some technical background on the machine and was informed the designer had avoided using a separate pump circuit for this function by tapping the main circuit (350 bar operating pressure) with a 2 millimeter orifice and pressure reducing valve (250 bar). Hand-operated directional control valves were used for cylinder control.<br /> <br /> The pressure required for unloaded cylinder extension was approximately 10 bar. I realized the pressure drop from 350 bar to approximately 20 bar was heating the hydraulic oil being supplied to the cylinders. And this was the root of the problem.<br /> <br /> To demonstrate the faultless function of the hydraulic cylinders I installed a ball-valve and pressure gauge at the cap-end port of the cylinder - to eliminate all other control elements.<br /> <br /> The cylinders were extended to the internal stop and pressurized to 250 bar. The ball valve was closed and the rod-end port connection was removed. As the hydraulic oil and cylinder body started cooling down, pressure decreased slowly to zero, although no leaking could be detected at the rod-end port.<br /> <br /> I explained to the engineers on site that the cause of their &#39;apparent&#39; problem was the heating and subsequent cooling of the oil being supplied to the hydraulic cylinders during static testing. But they still didn&#39;t believe me and remained of the view that the problem was a result of leaking seals.<br /> <br /> So to prove the point, I got a hot-air gun - normally used for packaging wrap and started to gently heat the hydraulic cylinder. As I expected, cylinder pressure started to increase. Seeing is believing... and at last my doubters were convinced!&quot;</em><br /> <br /> As this story shows, troubleshooting without <strong>confidence</strong> and <strong>conviction</strong> in your approach can result in costly mistakes. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, <a href="http://www.hydraulicsupermarket.com/"><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> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/hydraulics-work">Hydraulics At Work</a></li> </ul></div> http://hydraulicspneumatics.com/blog/effect-temperature-static-hydraulic-pressure#comments Hydraulics At Work Tue, 19 Apr 2016 00:51:00 +0000 38011 at http://hydraulicspneumatics.com NFPA Offers Latest Hydraulics-and-Pneumatics Industry Trends Report http://hydraulicspneumatics.com/technologies/nfpa-offers-latest-hydraulics-and-pneumatics-industry-trends-report <div class="field-byline"> Staff </div> <div class="node-body article-body"><p>The National Fluid Power Association (NFPA) released its latest update for hydraulic- and pneumatic-industry trends.&nbsp;Data was collected from more than 80&nbsp;fluid-power-product&nbsp;manufacturers&nbsp;by NFPA&rsquo;s&nbsp;<a href="http://nfpahub.com/stats/info-category/confidential-shipment-statistics-css-program/" target="_blank">Confidential Shipment Statistics (CSS) program</a>.&nbsp; The full report is available to NFPA&nbsp;members.</p> <p>Here is a look at&nbsp;a few graphs and charts to outline the current trends and anticipated changes in&nbsp;<span style="font-size: 12.8px; line-height: 20px;">hydraulic</span><span style="font-size: 12.8px; line-height: 20px;">&nbsp;and pneumatic</span> markets.&nbsp;</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/cylinders-actuators/market-report-explores-hydraulic-cylinder-industry ">Market Report Explores Hydraulic Cylinder Industry</a></p> <p><a href="http://hydraulicspneumatics.com/news/free-hydraulic-cylinder-app-performs-basic-calculations">Free Hydraulic Cylinder App Performs Basic Calculations</a></p> <p><a href="http://hydraulicspneumatics.com/construction/construction-equipment-market-builds">Construction Equipment Market Builds </a></p> </div> <h3><strong>Pneumatic, Mobile, and Industrial Hydraulic Orders Index</strong></h3> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/apr1_2.png" style="width: 595px; height: 314px; margin: 3px;" title="1. The data on the graph compares this year's orders to the previous year's orders. Each point can be read as a percentage. For example, industrial hydraulic orders received from February 2015 to January 2016 were 85.9% of the orders received from February 2014 to January 2015. (Base Year 2013 = 100)" /></p> <h3><strong>Total &ndash; Hydraulic and Pneumatic Shipments</strong></h3> <p><strong><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/apr2.png" style="width: 594px; height: 308px; margin: 3px;" title="2. According to the 12‐month moving average, both hydraulic and pneumatic shipments decreased in February 2016. (Base Year 2013 = 100)" /></strong></p> <p><strong>Shipments &ndash; Cumulative Year-to-Date % Change (2016 vs. 2015)</strong></p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/apr3.png" style="width: 595px; height: 145px; margin: 3px;" title="3. The table expresses percent differences between relevant cumulative total in 2016 and 2015. For example, the January pneumatic shipments figure of ‐14.9 means that for the calendar year through January 2016, pneumatic shipments decreased 14.9% compared to the same time period in 2015. (Base Year 2013 = 100)" /></p> <p>Overall,&nbsp;industry shipments of fluid-power products for February 2016 decreased 12.3% compared to February 2015, and increased 4.9% compared to last month.&nbsp;Mobile hydraulic, industrial hydraulic, and pneumatic shipments&nbsp;decreased in February 2016 compared to February 2015, and&nbsp;increased when compared to last month.</p> <p>More information is available to NFPA&nbsp;members; contact NFPA at (414)&nbsp;778‐3344 for more information.</p> <p><em>Eric Armstrong, overseer for the NFPA&rsquo;s fluid-power economic and statistical programs, is the author of the original article, which can be viewed <a href="http://news.nfpahub.com/april-hydraulic-and-pneumatic-industry-trends-update/?utm_source=Reporter+List+%28Master%29&amp;utm_campaign=737b41cae6-Latest_Headlines_April_14_2016&amp;utm_medium=email&amp;utm_term=0_7ad4fc47c0-737b41cae6-41804693" target="_blank">here</a> on the NFPA website. Eric Armstrong can be contacted at&nbsp;<a href="mailto:earmstrong@nfpa.com">earmstrong@nfpa.com</a>&nbsp;or (414) 778‐3372.</em></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/technologies/nfpa-offers-latest-hydraulics-and-pneumatics-industry-trends-report#comments Technologies Mon, 18 Apr 2016 15:00:00 +0000 38001 at http://hydraulicspneumatics.com Free Hydraulic Cylinder App Performs Basic Calculations http://hydraulicspneumatics.com/news/free-hydraulic-cylinder-app-performs-basic-calculations <div class="node-body article-body"><p>Those needing to calculate volume, force, velocity, outflow, and other parameters of double- and single-acting hydraulic cylinders now have a free resource at their disposal&mdash;Trelleborg&rsquo;s Hydraulic Cylinder app. Users start by entering the dimensions of their cylinder, including rod diameter, bore diameter, stroke, pressure rating, and oil flow. The app requires all inputs to conform to ISO 3320, 3321, and 4393.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/roundtable-meeting-discusses-upsides-low-barrel-prices">Roundtable Meeting Discusses Upsides of Low Barrel Prices</a></p> <p><a href="http://hydraulicspneumatics.com/news/expanded-rd-facility-advance-sealing-product-line ">Expanded R&amp;D Facility to Advance Sealing Product Line</a></p> <p><a href="http://hydraulicspneumatics.com/seals/trelleborg-embraces-digital-apps">Trelleborg Embraces Digital Apps</a></p> </div> <p>Standard hydraulic-cylinder equations calculate all values, which are useful for comparison to test or performance data. The app also lists the formulas as a reference for both students and experienced workers. Functions deliver results in both metric and inch units; &nbsp;sub-units are also provided.</p> <p>Trelleborg offers a range of other free apps, too, including a technical glossary for hydraulic terminologies and technologies.</p> <p><a href="https://itunes.apple.com/us/app/hydraulic-cylinder-design/id826281445?mt=8" target="_blank" title="Link to Hydraulic Cylinder iPhone app"><strong>Link to Hydraulic Cylinder iPhone app</strong></a></p> <p><a href="https://play.google.com/store/apps/details?id=com.tss.in.android.hydrauliccylinder" target="_blank" title="Link to Hydraulic Cylinder Android app"><strong>Link to Hydraulic Cylinder Android app</strong></a></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/news/free-hydraulic-cylinder-app-performs-basic-calculations#comments News Thu, 14 Apr 2016 20:19:00 +0000 37991 at http://hydraulicspneumatics.com Market Report Explores Hydraulic Cylinder Industry http://hydraulicspneumatics.com/cylinders-actuators/market-report-explores-hydraulic-cylinder-industry <div class="node-body article-body"><p>InterOcean Advisors, Chicago, is an investment bank focused on providing merger and acquisition and capital-raising advisory services to manufacturing companies. InterOcean is committed to the manufacturing industry, with expertise in the capital equipment, flow control, and other sectors.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/news/free-hydraulic-cylinder-app-performs-basic-calculations ">Free Hydraulic Cylinder App Performs Basic Calculations</a></p> <p><a href="http://hydraulicspneumatics.com/news/roundtable-meeting-discusses-upsides-low-barrel-prices ">Roundtable Meeting Discusses Upsides of Low Barrel Prices</a></p> <p><a href="http://hydraulicspneumatics.com/blog/study-summarizes-challenges-and-best-practices-b2b-marketing">Study Summarizes Challenges and Best Practices of B2B Marketing</a></p> </div> <p><a href="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Middle%20mkt.png"><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/Middle%20mkt.png" style="width: 366px; height: 221px; float: right; margin-left: 4px; margin-right: 4px;" title="This sample suggests that the majority of geographic concentration of hydraulic cylinder manufacturers lies within the Midwestern states. Interestingly, refuse and garbage collection seemed to be a common end market for companies based in California. Click on image for larger view." /></a>InterOcean&rsquo;s research and data analytics team recently released a report on the hydraulic cylinder industry focusing on trends, noteworthy opportunities, and possible threats.&nbsp;Based on its research, InterOcean concludes the industry as a whole has regained virtually all lost ground and stabilized at levels existing prior to economic decline in 2008 and 2009.</p> <p>Experts believe the positive outlook for certain end user markets such as material handling equipment and construction machinery is a promising sign that the industry will achieve a steady overall growth rate. Also, the industry is poised to benefit from the export potential for agricultural and aerospace equipment to the Asia-Pacific region. Adoption of mechanized agriculture and increased spending on infrastructure in developing countries such as China and India will likely benefit North American equipment vendors.</p> <p>William D. Doepke, Managing Director at InterOcean, offered, &ldquo;With both GDP and industrial production moving in a positive direction, the demand for equipment that requires hydraulic actuators is improving. Of course, this positive contribution is being somewhat offset by softness in commodity-dependent sectors, such as agriculture, mining, and oil &amp; gas.&rdquo;</p> <p><a href="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/US%20exports.png"><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/US%20exports.png" style="width: 333px; height: 179px; float: left; margin-left: 4px; margin-right: 4px;" title="Overseas demand for hydraulic cylinders is primarily driven by the need for high quality and heavy-duty components. Despite the increased strength of the U.S. dollar, demand for specialized, highly engineered components such as hydraulic cylinders may not be as affected as other more commoditized items. Click on image for larger view." /></a>The report also identifies potential threats posed by the fragile global economy and a strong U.S. dollar that may put pressure on exports and allow imports of hydraulic cylinders to be more cost competitive. Primarily driven by advancements in new technology and continued emphasis on quality, US-based industry participants are expected to experience a positive future.&nbsp;</p> <p>In addition, the report addresses recent industry mergers and acquisitions. Doepke added, &ldquo;We believe a fairly robust market exists currently &mdash; likely reflective of:<br /> 1) emphasis on gaining global scale,<br /> 2) efforts to achieve broader, stronger, product portfolios,<br /> 3) important private equity interest in the industry, and<br /> 4) market valuations meeting private owner expectations.&nbsp;</p> <p><a href="http://ioadvisors.com/wp-content/uploads/2016/04/2016-Hydraulic-Cylinders-Industry-Report.pdf" target="_blank"><strong><em>Click here</em></strong></a><em> to download a free copy of the report, or contact InterOcean Advisors LLC at </em><em>(312) 324-3053 or visit <a href="http://www.ioadvisors.com" target="_blank">www.ioadvisors.com</a>.</em></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/cylinders-actuators/market-report-explores-hydraulic-cylinder-industry#comments Cylinders & Actuators Thu, 14 Apr 2016 19:54:00 +0000 37981 at http://hydraulicspneumatics.com FAQs on Continuous Contamination Monitoring http://hydraulicspneumatics.com/hydraulic-fluids/faqs-continuous-contamination-monitoring <div class="field-deck"> Sponsored by MP Filtri </div> <div class="node-body article-body"><p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/MP-USA-logo141x100.gif" style="width: 100px; height: 71px; float: right;" />It&rsquo;s well documented that contamination is a major cause of hydraulic equipment failure. How do I know how much contamination is in a system? How can I determine if a new or existing machine meets a target ISO code? Every one of the machines we build uses hydraulics, so we go through hundreds of gallons of hydraulic fluid every week. I can&rsquo;t assume all this fluid is clean, so can I use a continuous contamination monitor for bulk hydraulic fluid?</p> <p>Download <em><strong>FAQs on Continuous Contamination Monitoring</strong></em> sponsored by <strong>MP Filtri</strong> to get the answers to these questions and more.</p> <p><br /> <script type="text/javascript"> document.write('\ <iframe style="height: 850px; width: 100%; border:0;” frameBorder="0" scrolling="no"\ src="http://pages.machinedesign.com/MD_Digital_MP-Filtri-ContaminationMonitoring_WP_JR_041216?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></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/hydraulic-fluids/faqs-continuous-contamination-monitoring#comments Design FAQs Maintenance Hydraulic Fluids Wed, 13 Apr 2016 22:56:00 +0000 37851 at http://hydraulicspneumatics.com Engineering Principles Kids Are Exploring at the USA Science Fair (.PDF Download) http://hydraulicspneumatics.com/datasheet/engineering-principles-kids-are-exploring-usa-science-fair-pdf-download <div class="field-image-promo"> <a href="/datasheet/engineering-principles-kids-are-exploring-usa-science-fair-pdf-download" class="imagecache imagecache-med_crop imagecache-linked imagecache-med_crop_linked"><img alt="" src="http://hydraulicspneumatics.com/site-files/hydraulicspneumatics.com/files/imagecache/med_crop/datasheets/thumbnails/Capture.JPG_.crop_display.jpg" title="" height="200" width="355" class="imagecache imagecache-med_crop" /></a> </div> <div class="node-body datasheet-body"><div>As editors and engineers, we too were&nbsp;once bitten by the technology bug and continue to be intrigued&nbsp;with the science of how things work. This handout is designed to&nbsp;help students (young and old) see&nbsp;the basic engineering principles&nbsp;of things they use, play with, drive, or enjoy in their daily lives.&nbsp;</div> <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> <table border="0" cellpadding="0" cellspacing="0" style="line-height:20px;width:642px;" width="570"> <tbody> <tr> <td style="line-height:inherit;"><img src="http://insidepenton.com/electronic_design/adobe-pdf-logo-tiny.png" style="border:0px;vertical-align:baseline;line-height:inherit;" /></td> <td style="line-height:inherit;"><a href="/site-files/hydraulicspneumatics.com/files/uploads/2016/04/ScienceFairDownload.pdf" target="_blank">Download this article in .PDF format</a><br /> This file type includes high resolution graphics and schematics when applicable.</td> </tr> </tbody> </table> </div> <div class="og_rss_groups"></div> Entertainment Community Wed, 13 Apr 2016 20:56:00 +0000 37971 at http://hydraulicspneumatics.com Compressed-Air Filter Product Roundup http://hydraulicspneumatics.com/air-filters-and-frls/compressed-air-filter-product-roundup <div class="node-body gallery-body"><p>These air filters target even the most sensitive applications, with unique features for space-saving capabilities, coalescing and particulate filtering mechanisms, and different operating pressures.&nbsp;</p> <p>Looking for Parts? Go do <a href="http://sourceesb.com/" target="_blank">SourceESB.com</a>.</p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/air-filters-and-frls/compressed-air-filter-product-roundup#comments Air Filters and FRLs Wed, 13 Apr 2016 15:10:00 +0000 37951 at http://hydraulicspneumatics.com Compressed Air Systems Rely on Proper Filtration http://hydraulicspneumatics.com/air-filters-and-frls/compressed-air-systems-rely-proper-filtration <div class="field-deck"> Airline filters come in a wide variety of sizes and configurations, but they all share the goal of capturing contaminants from compressed systems. Here is a review of some basics and a look at what is available. </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/compressed-air-systems-rely-proper-filtration-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>Engineers and system designers often choose compressed air due to the fact that it is readily available and easy to use, but simply setting up the system of piping without strong consideration of air filtration will lead to poor efficiency and inevitable failure. The simple act of compressing air can lead to a rise in air temperature. As the warm air moves through the system, it cools and creates moisture that can wreak havoc on the piping system. In addition to moisture, system designers must also be aware that rust and other contaminants, including oil carryover from the compressor itself, can compromise the efficiency of the system by reducing pressure and increasing energy consumption. For these reasons, designers must contemplate where and how to filter moisture and/or particles from their compressed air systems.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/air-filters-and-frls/filters-promote-air-system-reliability">Filters Promote Air-System Reliability</a></p> <p><a href="http://hydraulicspneumatics.com/air-filters-and-frls/coalescing-filters-protect-equipment">Coalescing Filters Protect Equipment</a></p> <p><a href="http://hydraulicspneumatics.com/air-compressors/monitor-air-quality-ensure-system-efficiency">Monitor Air Quality to Ensure System Efficiency </a></p> </div> <p>In recent years, filter manufacturers have been incorporating new filter materials to improve flow capacity and capture even smaller particles, down to 0.01 &micro;m, which improves efficiencies to 99.999%, in some cases.</p> <p>One of the most attractive reasons for using compressed air is its reliability. When properly filtered, compressed air systems can work uninterrupted for millions of hours. But even the tiniest particles can plug small orifices in the system and cause excessive wear or system failure. Proper selection of air filters can prevent probable short- and long-term issues in a pneumatic system.</p> <p>So what do you need to know about filtration? What are the important factors to consider when choosing the right filter for your application?</p> <p><strong>Contaminants Come in Small Packages</strong></p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Air_Filters_F1_0.gif" style="width: 350px; height: 421px; float: left;" title="1. Here is a cutaway view of airflow through a compressed-air point-of-use filter." /></p> <p>Filters are rated according to the <em>minimum</em> particle size that their elements will trap. Although filters rated at 40 to 60 &micro;m are adequate for protecting most industrial applications, many point-of-use filters are rated at 5 &micro;m. Finer ratings increase the pressure drop through the filter, which equates to higher energy cost to compress the air. In addition, finer filters clog more rapidly, also increasing pressure drop. Therefore, using a filter finer than necessary does no harm to downstream components, but increases air system operating cost.</p> <p>Many filter manufacturers will define the expected pressure loss and dirt-holding capacity, using curves related to pressure and flow. Therefore, particle-removal filters should be selected based on acceptable pressure drop and pipe-connection size. A typical pressure drop through such filters would be between 1 and 5 psig. A filter with larger body size will produce less initial pressure loss and provide longer operating life than a smaller-size filter with the same removal ratings.</p> <p>Most point-of-use filters claim to remove condensed water, typically via a form of cyclone separator at their inlet end <em>(Fig. 1)</em>. The water-removal efficiency of such filters is highly dependent on the incoming air velocity. Therefore, these filters must be matched to the intended airflow, rather than acceptable pressure drop. If the filter is intended to remove moisture, an integral automatic float-type drain should be provided to periodically remove accumulated liquids from the filter bowl.</p> <p>Generally, such filters have transparent polycarbonate bowls, which allow easy visual inspection of the sump level. Numerous chemicals can attack this plastic material and it only performs well at pressures below 150 psig and temperatures between 40&deg; F and 120&deg; F. A metal bowl may be required when the filter could be subjected to conditions outside those limits, as well as when synthetic compressor lubricants, which often contain chemicals that are harmful to polycarbonate, are present.</p> <p><strong>Moisture Barriers</strong></p> <p>Most oil entrained in a compressed air stream, as well as some of the condensed water, will be in the form of mists or aerosols that can pass through the openings in standard airline filters. Air for instruments, spray painting, and bulk-material conveying frequently requires the removal of such droplets. Coalescing-type filters will accomplish this job <em>(Fig. 2)</em>. Aerosol carryover through such filters is commonly stated as parts per million (ppm) of oil vs. air by weight and will range from 1 to as little as 0.01 ppm.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Air_Filters_F2.gif" style="width: 350px; height: 420px; float: right;" title="2. Here is a cutaway view of airflow through typical coalescing compressed air filter." /></p> <p>Coalescing filters are often rated to remove aerosols that are substantially smaller than the nominal size of the smallest solid particle that would be captured. Some models offer dual-stage filtration; the first removes solid particulates to protect the coalescing element in the second stage. Because all coalescing filters create a greater restriction to the airflow, pressure losses will be higher than those of conventional compressed air filters.</p> <p>Coalescing filters have an initial (or dry) pressure drop and a working (or saturated) pressure drop, both based on pressure and flow rate. The effective removal efficiency of such filters depends greatly on the air velocity passing through the filter assembly. Therefore, choose a coalescing filter based on acceptable oil carryover, expected airflow rate, and pipe-connection size. A coalescing filter rated at 0.1 ppm will typically have a clean, wetted pressure drop between 2 and 5 psig, while a high-efficiency filter rated at 0.01 ppm can cause as much as a 10 psig drop once it becomes wetted or fully saturated during service.</p> <p>The chart below from our Designer&rsquo;s Guide lists manufacturers of airline filters, and provides sizes, ratings, and specifications about products offered by each company.</p> <p><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></p> <p><a href="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/AutomateTable_top-big_0.gif" target="_blank"><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/AutomateTable_top-big_0.gif" style="width: 595px; height: 396px;" /></a></p> <p><a href="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/AutomateTable_bottom-big.gif" target="_blank"><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/AutomateTable_bottom-big.gif" style="width: 595px; height: 356px;" title="(Click on top or bottom of table to enlarge image.)" /></a></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/air-filters-and-frls/compressed-air-systems-rely-proper-filtration#comments Air Filters and FRLs Wed, 13 Apr 2016 13:58:00 +0000 37931 at http://hydraulicspneumatics.com Electrical Connector Lets You See the Light http://hydraulicspneumatics.com/fittings-couplings/electrical-connector-lets-you-see-light <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/electrical-connector-lets-you-see-light-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>When troubleshooting a hydraulic system, it&rsquo;s often discovered that the problem is not hydraulic at all, but rather electrical. And in the realm of electronics, connectors are notorious for being sources of malfunctions. Worse yet, when bad connections occur intermittently, it seems like they&rsquo;re working fine when you check them; then they act up again when you move on to check something else.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/products/connector-selector">Connector Selector</a></p> <p><a href="http://hydraulicspneumatics.com/200/TechZone/FluidPowerAcces/Article/False/85062/TechZone-FluidPowerAcces">Hybrids Make the Connection</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-fluids/no-tee-two">No Tee for Two</a></p> </div> <p>Brian Smith, owner of SDSi LLC, came up with a patented solution that makes it easy to see if power is getting through. His U.S. patent covers the 2PLC connector (male plug and molded cable assembly), which is compatible with Deutsch 2-pin DT04-2P, Amphenol AT02-2P, and compatible receptacles often molded into electrohydraulic solenoid valves and switches.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/2PLC-2-glow.WEB_.jpg" style="width: 595px; height: 423px;" title="The 2PLC lighted connector indicates that power is being transmitted to an electrohydraulic valve or other component. The industry-standard connector also comes in a 4-pin version." /></p> <p>Smith realized the value of proprietary LED-indicating connectors from OEMs, but was frustrated to learn the feature was not offered in industry-standard connectors. He began developing the 2PLC connector in 2010 and subsequently acquired IPX9K certification. The connector not only visually indicates continuity, but it withstands the harsh environmental conditions typically encountered with off-highway hydraulic systems. Potential applications include construction, mining, forestry, oilfield, agricultural, and waste-handling equipment.</p> <p>More recently, Smith introduced the 4PLC, a 4-pin lighted connector. Both connectors carry a 12/24-V dc, 13-A rating. They feature a thermoplastic housing and elastomer sealing gasket to exclude dirt and moisture, plus two-part polymer epoxy plug potting to further prevent moisture wicking and failures from shock &nbsp;or vibration. Custom cable lengths and harness assemblies with up to six plugs are made to order.</p> <p><em>For more information, call (817) 449-7642, email <a href="mailto:sales@2plconline">sales@2plconline</a>, or visit <a href="http://www.2plconline.com" target="_blank">www.2plconline.com</a>.</em></p> <p><strong><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></strong></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/fittings-couplings/electrical-connector-lets-you-see-light#comments Fittings & Couplings Tue, 12 Apr 2016 18:59:00 +0000 37911 at http://hydraulicspneumatics.com Pneumatic Ballast Control Keeps Ships Fit for High Seas http://hydraulicspneumatics.com/pneumatic-valves/pneumatic-ballast-control-keeps-ships-fit-high-seas <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/pneumatic-ballast-control-keeps-ships-fit-high-seas-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/CargoShip.gif" style="width: 595px; height: 397px;" title="Trimming of ballast tank systems ensures ship stability by compensating for uneven load distribution of cargo. (Courtesy of Can Stock Photo/Anke)" /></p> <p>Water is commonly used in ships to provide stability and counteract against uneven loads. Depending on the weight and distribution of the load in the hull, ballast-valve control systems open or close valves to either flood or empty the ballast tanks within a ship&rsquo;s hull. Known as trimming, it generates counterweights on demand, keeping the ship stable.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/controls-instrumentation/taking-guesswork-out-pneumatic-control">Taking the Guesswork Out of Pneumatic Control</a></p> <p><a href="http://hydraulicspneumatics.com/hydraulic-valves/controlling-sequence-events">Controlling a Sequence of Events</a></p> <p><a href="http://hydraulicspneumatics.com/pneumatic-valves/air-valves-pull-three-shifts">Air Valves Pull Three Shifts</a></p> </div> <p><strong>Trimming it Up</strong></p> <p>Traditionally, rotary hydraulic valve actuators have been used to trim operations. Hydraulic actuators are small and powerful, but they require two fluid lines: one for supply and one for return. Plus, with today&rsquo;s increased environmental awareness, the potential for fluid leaks becomes an issue. Electrical valve actuators could also be used, but ensuring safe operation in these rugged, underwater applications makes them expensive.</p> <p>Wouter-Jan Hunsche, of Aventics&rsquo; Marex Group, explains, &ldquo;Shipyards want to avoid the expense of installing two runs of tubing for each actuator. At the same time, operators increasingly are adopting the safe and environmentally friendly medium air.&rdquo;</p> <p>This application also demonstrates how pneumatics technology can be the most economical solution. Pneumatic tubing and other components are significantly less expensive than their hydraulic counterparts. Hunsche adds, &ldquo;Shipyards have confirmed a cost advantage of around 30% compared with hydraulics.&rdquo; Another advantage he cites is that crew members can easily service pneumatic systems on the high seas with tools on board.</p> <p>Hunsche points out another important requirement of these systems: &ldquo;The system has to continue functioning if a power failure occurs, even if the valves are completely submerged.&rdquo; The pneumatic actuators of the Marex Valve Control System (VCS) can be mounted in the ballast tanks and adjusted with no need for electricity. Pneumatic transmission prevents short circuits in the ballast tanks. An active pneumatic position display, the feedback line, sends the valve position to a controller without current, ensuring reliable monitoring.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Ship-with-text.png" style="width: 596px; height: 278px;" title="The Marex Valve Control System uses pneumatic valve actuators to control ballast, even if a power outage occurs." /></p> <p>Depending on the size of the ship, a Marex VCS can work up to 100 ballast and quick-release valves, including air preparation and all necessary operating and control modules. The standard working pressure is 5 to 7 bar, and if a power failure occurs, the crew can generate working pressure using one or more manual pumps.</p> <p><strong>In the Control Room</strong></p> <p>Marex AMC operating and control modules can control the ballast-valve control system. This automation system, used extensively in shipping, allows structured access to all ballast-valve control-system information and functions. Furthermore, it groups and displays additional systems, such as the engine, reversing gear, and other functions.</p> <p>The modular system communicates with the ballast-valve control system via CAN bus. It features a self-explanatory touchscreen controller that mimics the ship&rsquo;s movements and simplifies operation&mdash;a major demand within the shipping industry.</p> <p>If the main system fails, the valves can be controlled via a backup control and backup system, which are located outside the engine control room. This includes one or more manual pumps that ensure the ability to function in the event of a power outage.</p> <p>These purely pneumatic actuators function in a wide range of environments: ballast, bilge, and heavy fuel-oil tanks. The Marex systems meet ATEX specifications for all ships and installations with explosive protection requirements.</p> <p>Hunsche adds that the Marex VCS is certified for use in ships and offshore installations by the world&rsquo;s leading classification societies. &ldquo;The system is based on large-scale series components that are available across the globe.&rdquo;</p> <p><em>For more information on Marex and other Aventics products and services, visit <a href="http://www.aventics.us" target="_blank">www.aventics.us</a> or call (</em><em>859) 259-3817</em><em>.</em></p> <p><strong><em>Looking for products? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></strong></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/pneumatic-valves/pneumatic-ballast-control-keeps-ships-fit-high-seas#comments Controls & Instrumentation Cylinders & Actuators Marine & Offshore Pneumatic Valves Tue, 12 Apr 2016 14:52:00 +0000 37891 at http://hydraulicspneumatics.com Hydraulics Serves Aussie Navy http://hydraulicspneumatics.com/marine-offshore/hydraulics-serves-aussie-navy <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/hydraulics-serves-aussie-navy-pdf-download">Download this article as a .PDF file</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/Landing-craft-Lead.gif" style="width: 595px; height: 332px;" title="The HMAS Canberra docks down in Sydney Harbor to receive an LHD Landing Craft containing a powerful hydraulic ventilation drive. (Courtesy of Royal Australian Navy)" /></p> <p>For nearly 40 years, <a href="http://www.fluidmecanica.com/index_en.php" target="_blank">Fluidmecanica SAU</a>, Pontevedra, Spain, has designed and manufactured marine machinery, hydraulic controls and transmission, and pneumatic systems. Last year, four military landing craft worked on by Fluidmecanica were delivered to the Royal Navy of Australia at its HMS Waterhen Naval Base near Sydney. The landing craft operate in conjunction with two Canberra-class landing helicopter dock ships and are qualified under NATO requirements.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/hydraulic-fluids/hydraulic-fluids-meet-tighter-requirements-marine-vessels">Hydraulic Fluids Meet Tighter Requirements for Marine Vessels </a></p> <p><a href="http://hydraulicspneumatics.com/other-technologies/offshore-technology-conference-open-industry-professionals-students-alike">Offshore Technology Conference Open to Industry Professionals, Students Alike</a></p> <p><a href="http://hydraulicspneumatics.com/blog/hydraulics-aftermath-pearl-harbor">Hydraulics in the Aftermath of Pearl Harbor</a></p> </div> <p>Each landing craft is 23.30 meters long and can achieve speeds exceeding 20 knots. Fluidmecanica designed and built the ventilation system for the engine room of each craft. A ventilation system may seem like overkill for a hydraulic system, but the rigors of the application requires the high power density and durability of hydraulics.</p> <p><strong>Hydraulics on the Move</strong></p> <p>Two pairs of hydraulically powered blowers rotate at 2,900 rpm to move up to 17,000 m<sup>3</sup> of air per hour (10,000 cfm). Each hydraulic gear motor (two connected in series) driving a fan is fed by a variable-displacement hydraulic piston pump powered from each of the landing craft&rsquo;s two 809-kW (1,080 hp) engines. Hydraulic pressure for each circuit is 280 bar, and maximum flow is 10 lpm. &nbsp;This is where the versatility of hydraulics is important, because fan speed must be controlled independent of engine speed.</p> <p>Fluidmecanica&rsquo;s Francisco Oliver Rivera explains that a variable-speed electric drive would not have been practical for this application. &ldquo;An electric drive is more bulky and weighs about 60% more. It would also be prone to failure under high shock and vibration. NATO shock requirements are especially demanding in boats like this, which may have to operate near shelling fire during operations.&rdquo;</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/Landing-craft-093454.gif" style="width: 595px; height: 446px;" title="Fluidmecanica tests a ventilation fan driven by a hydraulic gear motor. Two pairs of these fans are used in landing craft designed and built for the Royal Australian Navy." /></p> <p>The pump that drives the fan has variable displacement, so its output per revolution increases or decreases inversely with engine speed, says Rivera. &ldquo;Each pump has a load-sensing control, so we achieve fixed flow with a metering block. In this case, the flow remains fixed over the engine&rsquo;s complete range of speed&mdash;from 1,000 to 2,800 rpm.</p> <p>Rivera also says that because the landing craft are designed for use in combat, simplicity and rugged operation were high priorities. &ldquo;Each hydraulic pump is directly coupled to the engine, so the system automatically starts with the engine. There is no need to switch the fan on or off, because if the engines are not running, the fans are not needed.&rdquo;</p> <p><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB</a>.</em></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/marine-offshore/hydraulics-serves-aussie-navy#comments Marine & Offshore Hydraulic Pumps & Motors Tue, 12 Apr 2016 13:42:00 +0000 37871 at http://hydraulicspneumatics.com How NOT To Go Down The WRONG Rabbit Hole When Hydraulic Troubleshooting http://hydraulicspneumatics.com/blog/how-not-go-down-wrong-rabbit-hole-when-hydraulic-troubleshooting <div class="node-body blog-body"><p>One of our members wrote me about the following problem:<br /> <br /> <em>&quot;I wonder if you could help shine some light on a problem I am having with my railroad club locomotive. It is a 1/8th scale, gasoline-hydraulic driven unit. Up until a few months ago the locomotive was able to pull 10 heavy cars up a 2% grade without any problem. Recently however, the locomotive began making noises and jerky movements. Today I watched the three driven axles in the front of the engine and the three driven axles in the rear. They both behaved the same way.<br /> <br /> When the locomotive was pulling the train on level ground there was no problem. But when the train began pulling the 2% grade the jerking began and I noticed that the hydraulic motor shafts (one driving each set of three axles using chains) did not turn smoothly. This is the source of the jerking effect. I thought the hydraulic fluid may be low so I checked the tank and found that it was nearly full but I was able to add another 1 gallon of hydraulic oil.<br /> <br /> The locomotive was built and delivered in 2004. The motors are low rpm, high torque type. No maintenance has been performed on them since manufacture. Same for the pump. What are the failure modes of hydraulic motors and pumps that might give me a clue as to which is the most likely suspect? The motors are easy to remove and inspect while the pump is a real problem to get access to.&quot;</em><br /> <br /> If you&#39;d like a little challenge, pause your reading here and take a moment to consider the problem described above and jot down how would advise this member to proceed, and why.<br /> <br /> Ready? Good. Now read on...<br /> <br /> Every troubleshooting assignment begins, one way or another, with a bunch of information you&#39;re given. Some of it will be fact. Some of it will be opinion. Some of it will be fiction. How you sift and process this information determines which rabbit hole you go down first. Moreover, how SYSTEMATICALLY you sort this initial information will determine whether you go down the CORRECT rabbit hole first. And this is VERY important if you&#39;re to get a fast and accurate diagnosis.<br /> <br /> So with this in mind, I&#39;m not going to wing it. I&#39;m going to begin the process by referring to the checklist on page 83 of <strong>The Hydraulic Troubleshooting Handbook</strong>. Question #1 on this checklist inquires of me: What conclusions can be drawn considering the symptoms of the problem in relation to the physical laws of hydraulics? This interrogation prompts me to review chapter 1 which explains the 7 physical laws as they relate to troubleshooting.<br /> <br /> After doing this, the most sensible conclusion I can come to is the described symptoms (jerky, intermittent drive) are NOT consistent with a typical HYDRAULIC problem. Yes, any type of fault is possible. But this does not make it probable. And probabilities are important when troubleshooting.<br /> <br /> Next, question #2 on the checklist inquires of me: Based on the above conclusions, what diagnostic tools are most appropriate and are they available to you? This interrogation prompts me to review chapter 2 which covers diagnostic tests. But I don&#39;t need to at this point. Because we&#39;re not ready for any diagnostic tests at this stage. Reason being, I want to fully explore my suspicion that this is NOT a hydraulic problem.<br /> <br /> So I move on to question #3, which asks me: Have you carefully considered and listed all the easy things to check? And this interrogation prompts me to review chapter 3, which among other things contains a list of 15 items which should always be checked BEFORE reaching for any diagnostic tools. Number one on this list is: Level of oil in the tank. And our member has already checked this, which is good.<br /> <br /> Also on this list is: The coupling between prime mover and pump; and between motor and final drive. So now, based on the information available, AND my systematic processing of it with the aid of The Hydraulic Troubleshooting Handbook, I&#39;ve determined this is the rabbit hole we should go down first.<br /> <br /> Since the motors on this machine are more easily accessible than the pump, I wrote back to this member and advised him to check the mechanical coupling, key, sprocket, etc. between the hydraulic motors and wheels; and between the pump and engine--in that order.<br /> <br /> A couple of days later he wrote back:<br /> <br /> <em>&quot;I performed a pull test on the locomotive and found the problem. As you suspected, the problem was not hydraulic. One of the drive chain sprockets had its teeth worn down to nubbins. If the load was low enough the chain would stay in place on the sprocket. But when higher loads were applied, the chain jumped from one nubbin to another thus causing the jerk.&quot;</em><br /> <br /> The almost natural, automatic reflex when confronted with the detail of this problem is to assume it is hydraulic. And imagine the PAIN if you did: breaking into the system, losing oil, finding the adapters to install a flow-meter, the work involved in removing the motors and gaining access to the pump. Only to figure out eventually it was the chain drive.<br /> <br /> No, you don&#39;t want to go down the wrong rabbit hole if you can avoid it. And this is just one of the reasons why <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=thth"><strong>The Hydraulic Troubleshooting Handbook</strong></a> is such a valuable tool: it stops you from jumping to conclusions and then going down the wrong rabbit hole.<br /> <br /> PLUS as demonstrated above, it keeps bringing you back to the 12 key PRINCIPLES of troubleshooting that always ensure you get the correct diagnosis in the shortest possible time. Without it, your path from problem to correct resolution is likely to be unreliable, more time consuming and costly.<br /> <br /> <a href="http://www.hydraulicsupermarket.com/track?p=handp&amp;w=thth">Learn more about <strong>The Hydraulic Troubleshooting Handbook</strong> here</a></p> </div> <div class="og_rss_groups"><ul class="links"><li class="og_links first last"><a href="/blog/hydraulics-work">Hydraulics At Work</a></li> </ul></div> http://hydraulicspneumatics.com/blog/how-not-go-down-wrong-rabbit-hole-when-hydraulic-troubleshooting#comments Hydraulics At Work Tue, 12 Apr 2016 00:29:00 +0000 37861 at http://hydraulicspneumatics.com How to Select a Mobile Hydraulic Heat Exchanger http://hydraulicspneumatics.com/heat-exchangers/how-select-mobile-hydraulic-heat-exchanger <div class="field-byline"> Paul Badowski, Cross Co. </div> <div class="field-deck"> Sizing and selecting a heat exchanger for hydraulics isn’t always straightforward, especially when the equipment works in a wide variety of ambient temperatures and load conditions. </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/how-select-mobile-hydraulic-heat-exchanger-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>Sizing and selecting a heat exchanger to cool a mobile hydraulic system presents some real challenges. First, you have to come up with an accurate assessment of how much heat the system will generate. Then you have to account for varying load conditions, ambient temperatures, and changes that may occur over time.</p> <div class="related-content"> <div class="related-label">Related</div> <p><a href="http://hydraulicspneumatics.com/blog/how-connect-forced-air-heat-exchanger">How To Connect A Forced Air Heat Exchanger</a></p> <p><a href="http://hydraulicspneumatics.com/heat-exchangers/spotlight-heat-exchangers">Spotlight: Heat Exchangers</a></p> <p><a href="http://hydraulicspneumatics.com/200/TechZone/FluidPowerAcces/Article/False/6451/TechZone-FluidPowerAcces">Engineering Essentials: Heat Exchangers</a></p> </div> <p>Sometimes it can seem like shooting darts and hoping that your decision will score a bull&rsquo;s-eye. Should you double the oil cooler&rsquo;s size to keep the hydraulic system extra cool?&nbsp; Would a better choice be to use a smaller heat exchanger made of premium materials that can increase the heat dispersion? Where is equilibrium between size and efficiency?</p> <p>Even after carefully calculating a system&rsquo;s heat load and coming up with figures you are confident with,&nbsp;unforeseen factors may creep in during development. For instance, engine compartments might be smaller than anticipated and fresh-air flow could be restricted. Engine manufacturers provide specifications for heat removal, and most heat exchanger companies will adjust to make sure they have a large enough cushion above these specifications. The same should be done with hydraulics.</p> <p><strong>Importance of Removing Heat</strong></p> <p>A good general rule for a mobile hydraulic system is that one-third of the input power will need to be removed as heat. For example, a hydraulic system driven by a 75 hp engine will produce about 25 hp of heat, which needs to be removed. Many industrial hydraulic systems can dissipate heat through their reservoir. A large reservoir provides large surface areas to transfer heat from the hydraulic fluid to the external surroundings. However, reservoirs in mobile hydraulic systems generally are made as small as practical and often located where little opportunity for heat transfer exists.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/MobileInstallation.jpg" style="width: 595px; height: 447px;" title="Mobile equipment presents special challenges for removing heat from hydraulic systems. As shown here, heat exchangers must often be placed in inaccessible areas with limited space. (Photo courtesy of Thermal Transfer Products/AP Heat Transfer)" /></p> <p>Without adequate cooling for the hydraulic system, the hydraulic oil will overheat, causing it to quickly degrade. Providing a high-temperature shutoff switch can help protect the system from extreme overheating. However, shutting down the hydraulic system renders the equipment unusable until ambient air cools the fluid back down to below the switch&rsquo;s shutoff temperature. Not only is this downtime unacceptable in most cases, but the system will probably operate at fluid elevated temperatures most of the time. Again, this will cause problems quickly degrading the hydraulic fluid.</p> <p><strong>Heat-Exchanger Options</strong></p> <p>The solution, then, is to incorporate a heat exchanger into the hydraulic system. A heat exchanger routes the hydraulic oil through narrow passages with large surface areas that transfer heat from the hydraulic oil to a fluid (usually air or water) that carries heat away. So the first question in selecting a heat exchanger is whether to use water cooling or air.</p> <p>Industrial hydraulic systems often use water-cooled heat exchangers. Water is very effective at transferring heat, but it is rarely a realistic option for mobile equipment. That&rsquo;s because engine coolant usually runs at temperatures of 180&deg; F or higher, which exceeds the maximum temperature recommended for most hydraulic fluids. Even if the fluid could tolerate high temperatures for extended periods, the temperature differential between the hydraulic fluid and the water would be insufficient to provide significant cooling. So scratch off water.</p> <p>That leaves us with air-to-oil heat exchangers. You can&rsquo;t rely on ambient air alone to provide enough heat transfer to cool the hydraulic oil in a heat exchanger. Instead, a fan is needed to force ambient air through the heat exchanger. However, air temperature can vary dramatically with mobile equipment. A single machine may operate in below-freezing temperatures much of the time, and in temperatures exceeding 100&deg; F at other times. Loads can also vary widely because equipment may require little cooling while running in standby mode for long periods. However, that same machine may require maximum cooling while operating at full load.</p> <p>This means an air-to-oil heat exchanger should be selected to provide maximum air flow for the severest operating conditions, but operate more efficiently by providing less air flow when the hydraulic system requires less cooling. The traditional method to move air through a heat exchanger was to use an engine-driven fan. However, motor-driven fans have proven to provide more effective and more energy-efficient cooling than a fan running at engine speed. The fan operates at full speed when maximum cooling is needed, and they run at slower speeds&mdash;or not at all&mdash;when less cooling is called for. They can even rotate in reserve to help clean the heat exchanger by blowing debris out.</p> <p>Heat exchangers have a coolant fluid sweet spot. If you choose a huge cooler and put only minimal fluid through it, the system will not operate efficiently. Plus, you have spent more money when a smaller, less-expensive cooler would have been more effective. On the other hand, if you try to push too much fluid through a smaller cooler, you reach a point at which the system is saturated and cannot remove any more heat. This would increase pressure drop and create even more heat to only make the problem worse.</p> <p><strong>Hydraulic or Electric?</strong></p> <p>You can use hydraulic oil to power a hydraulic motor and rotate a fan. If hydraulic flow is readily available, or the system allows enough extra power to produce this flow without hindering the machine&rsquo;s operation, this can be a great option. The efficiency of the hydraulic motor should be considered against other options&mdash;an electric motor for instance. The advantage of hydraulics is that the flow and pressure needed to develop the necessary power (fan speed) in these cooling systems is already available on the machine.</p> <p><img alt="" src="/site-files/hydraulicspneumatics.com/files/uploads/2015/03/DHdiagramWEB.jpg" style="width: 595px; height: 371px;" title="Air-to-oil heat exchangers use a fan to blow cool air between fins, which transfer heat from hydraulic oil in tubes to the cool air. (Photo courtesy of Thermal Transfer Products/AP Heat Transfer)" /></p> <p>The other choice is to use an electric motor to spin a fan. These systems are usually on smaller mobile systems, but larger machines may use multiple electric fans, which can run at different speeds or not at all, depending on cooling demand. A consideration with electric fan drives is that the machine&rsquo;s electrical system must have the capacity to drive the electric motor or motors. The controls available for the electric fan are inexpensive, and the fan speed can be easily altered. This can be an easy-to-install system can run very efficiently.</p> <p><strong>Other Considerations</strong></p> <p>Now we need to know how we are going to get the oil or fluid into and out of the cooler. There are also correction factors for the type and viscosity of hydraulic fluid being used. Additional questions must also be factored into the final solution.</p> <p>Does the system have enough flow to reliably pump the fluid through the cooler, allowing the heat transfer to take place? If not, can you incorporate an additional pump solely to circulate oil through the cooler. This setup is often referred to as a kidney loop and presents an opportunity to provide additional filtration for the hydraulic system.</p> <p>Can pressure spikes or flow surges be transmitted to the oil lines going to or from the oil cooler? If so, you must determine what the maximum intermittent pressure will be. If not accounted for, pressure surges even of very short duration can create leaks in the heat exchanger. Solutions would be to take measure to dampen spikes or specify a heat exchanger that can accommodate the peak pressures.</p> <p>Ensure that the heat exchanger can handle up to the worst conditions anticipated. Can the heat exchanger provide enough cooling with the system operating at its highest temperature in the highest ambient temperatures?</p> <p><strong>A Short Scenario</strong></p> <p>Let&rsquo;s go back to the hypothetical example above, where we estimated that we need to remove 25 hp of heat from our hydraulic system. Following is a common situation I have encountered in my 15 years of working with hydraulic applications.</p> <p>Say your system uses Chevron AW46&nbsp; hydraulic fluid. Assume maximum return flow from several hydraulic motors varies from 30 to 40 gpm with no pressure spikes. Further assume the machine will be running in ambient temperatures that vary from 40&deg; F in the winter to 95&deg; F in the summer.</p> <p>Do you want the fan to run continuously or only after the system reaches a certain temperature? A continuously running fan can spin at variable speed to match cooling capacity to the heat load. This is the best solution for a hydraulic system because it keeps the temperature of the hydraulic fluid relatively stable.</p> <p>Most mobile equipment operates in dirty environments, with a high potential of airborne dust and dirt. Therefore, you probably want the fan to push air through the cooler rather than pull air into the cooler. The machine has a dc electrical system, but you don&rsquo;t want to place the additional load of a fan motor on the battery, so you opt for a hydraulic motor driven fan system. You&nbsp;have a fair amount of space to mount a cooler but want some options before deciding on a mounting envelope.</p> <p>This is a lot of variables.&nbsp;If you want peace of mind, now is the time to call in a heat exchanger professional. He or she could be a Certified Hydraulic or Fluid Power Specialist or technical rep from a heat exchanger manufacturer. Either way, they can take the information you provide and offer suggestions on the material makeup (copper shell and tube or aluminum extrusion), size and shape, larger overall package or smaller package with higher fan speed, plus any other systemic factors to optimize your system.</p> <p><em>Paul Badowski is Account Manager, Mobile Hydraulics &amp; Control Systems Group at Cross Co. For more information, call (336) 856-6000, visit <a href="http://crossfluidpower.com" target="_blank">crossfluidpower.com</a>, or view blogs at <a href="http://crossfluidpower.com/blog" target="_blank">crossfluidpower.com/blog</a>.</em></p> <p><strong><em>Looking for parts? Go to <a href="http://sourceesb.com/" target="_blank">SourceESB.</a></em></strong></p> </div> <div class="og_rss_groups"></div> http://hydraulicspneumatics.com/heat-exchangers/how-select-mobile-hydraulic-heat-exchanger#comments Heat Exchangers Mon, 11 Apr 2016 16:07:00 +0000 37831 at http://hydraulicspneumatics.com