Mature, but not stagnant
Think fluid power is a mature technology where not much is happening? Think again. For example, in July, we wrote about the Sanderson mechanism, an assembly that converts rotational motion to linear, or vice versa. It is said to be dramatically more efficient than conventional crank mechanisms and is being licensed for use not only in gasoline and diesel engines, but in air compressors and hydraulic pumps and motors as well. Its promoters offer that it holds promise to increase the use of fluid power because the hydrostatic drives using this mechanism would be much more efficient than mechanical and electromechanical alternatives.
Our August issue described a variable-speed hydraulic fan drive for diesel engines. By keeping a diesel engine running at its optimum temperature, this system has shown to boost fuel economy and reduce emissions at the same time.
In September, our cover story described a truly self-contained hydraulic system. Manifolds containing integrated hydraulic circuits have become fairly common, but this concept goes one step further by also integrating the hydraulic pump and cylinder - essentially, the entire hydraulic system - all into a common manifold. We call this stealth hydraulics, because an observer may not even realize that this plug-and-play motion system relies on hydraulics - just hook it up to electrical power and feed it a control signal.
And just last month we described a new type of hydraulic power unit that uses a variable-speed electric motor driving a fixed-displacement hydraulic pump instead of the conventional fixed-speed motor and variable-displacement pump. This concept has been talked about and attempted for decades, but it took today's technology and computing power to make this type of system practical.
But what's really impressive were some of the innovations I learned about at NFPA's Education-Industry summit held in Indianapolis in October. Most of the program described cooperative efforts between industry and universities and how they come about. The greatest impact came from the presentations - some showing fluid power used in used in applications nothing short of Star Wars or The Six Million-Dollar Man.
One video showed a human-like robot walking over irregular terrain. The problem is, even with its high-tech battery pack, the robot can walk (while performing no other work) for no more than 20 minutes. An alternative power system using a form of pneumatics was presented that potentially would last several times longer, and the pneumatic actuators would be lighter and more compact than their existing electromechanical counterparts.
Another video showed hydraulically powered exoskeletons that could replace the motion normally produced by muscles. This technology could some day restore motion and control lost by victims of paralysis. It could also allow people to carry heavy payloads far beyond their natural capabilities.
Who knows? Maybe some day this technology will help a couch potato like me to be able to strut around like Arnold Schwarzenegger - the action hero, not the politician.
Alan L. Hitchcox