By Josh Cosford, Contributing Editor
Do you ever find yourself having difficulty with electronics? I was out for dinner with my future father-in-law last night, and during one discussion, he tried to find an email he had previously deleted from his Blackberry (don’t laugh, I have one too). He spent many moments flipping and pinching through screens, but for the life of him couldn’t find his deleted folder. He is a successful man in his early sixties, and he owns a flourishing hydraulic manufacturing and distribution company. He has many talents and achievements, is very intelligent and is a world-class runner.
But that difficult interaction with a piece of touch-screen hardware had me thinking—is this the world I live in and promote? Am I a hydraulic boy in an electronic world? Am I doomed to be working on decades-old technology while my children design automated flying cars or smart watch apps that track your bowel movements?
Playing devil’s advocate to myself, why shouldn’t I be happy with fluid power, where it’s at and where it’s going? The advancements in the fundamental understanding and use of fluid power hasn’t changed much in a century, and recent advancements have only contributed to how fluid power is controlled, observed and maintained. Force—and lots of it—is still be transmitted via compressed fluid, and even if market growth isn’t parallel to electric cars and Bluetooth home automation hubs, fluid power isn’t going anywhere soon.
I compare fluid power to electrics every so often, and I also mention why fluid power (especially hydraulics) will never die in our lifetimes. If you’re also a hydraulic boy or girl in an electronic world, let me tell you why your industry, career and retirement package is safe. Electronic actuators will never be able to achieve the force capable with fluid power actuators. Even a cooled super-conductor has limitations in magnetic field creation when all atoms are simultaneously polarized.
With the compression of fluid, there is no limit to force density (unless and until the universe collapses upon itself again with near-infinite density). 10,000 psi actuators are common, providing 1-in. bore cylinders the capacity to achieve nearly 8,000 lbs of force. Even with today’s technology, hydraulic boosters can easily achieve 50,000 psi, providing that same 1-in. bore actuator with nearly 40,000 lbs of force.
Looking at one of the leading electric linear actuator manufacturers, they offer a unit with maximum force of 13,000 lbs, which is easily outclassed by a 2.5-in. bore cylinder running only 3,000 psi. The hydraulic cylinder also weighs significantly less, is more compact, costs less, easier to repair, and with appropriate seals, can handle higher velocities and weather/temperature extremes. Okay, I’ll throw the electric actuator a bone … it’s cleaner.
Will electric actuation one day match what can be done with hydraulics? It may get close in some regards, but it can’t close the gap on every current advantage. With this knowledge in mind, it’s not so bad being a hydraulic boy in an electronic world. I was, after all, able to write this entire article on my Blackberry.