Ultra Motion provide linear actuators accommodate heavy loads, high bending moments and deliver long service life. For 20 years, Ultra Motion has been supplying high performance actuators to research facilities, national laboratories, and universiti
It sounds really impressive: linear actuator. Something a man in a white lab coat might say to the sound of crackling thunder. It’s nothing as intimidating or hard to understand as that, they’re really simple devices when you understand how they work.
A linear actuator changes non-linear energy, like heat, pressure or electricity, into linear motion. That means motion in a straight line. You can imagine how useful that is. We bet there’s one within 20 feet of where you are now. If it has an electric hoist or drive, hydraulic piston or pneumatic cylinder, it’s got a linear actuator.
There are a lot of different ways in which we use linear actuators but they all rely on the same conversion of non-linear energy into motion in one direction. Some use compressed gas or pressurized fluid to move whatever is attached to the end in the right direction. Others use a magnetic motor to convert electrical potential energy into movement energy. This is how the disc tray in your PC works. Told you there was one within 20 feet of where you are!
That kind of drive, with an electric motor, is called a rotary linear actuator. You might think that rotary and linear are contradictions in terms but you’d be wrong: the product of the energy conversion is linear, after the rotation has been converted on the cam or lead screw into the forwards and backwards motion of the actuator arm.
Piezoelectric linear actuators (an even more impressive sounding phrase) use the fascinating and useful property some materials have, where they expand when an electrical current is applied, to create linear motion. These are tiny effects, so they are used in high precision instruments.
Hydraulic linear actuators use a cylinder filled with a fluid that, because fluids are almost completely incompressible, moves the actuator arm when the pressure is increased on the fluid. These can be enormously powerful, you see them on construction sites and in the bowels of enormous ships, turning screws and pushing and pulling really heavy things.
Pneumatic linear actuators work with the principle that the gas in the cylinders is compressible. The compressed air forces the actuator arm to move in a powerful and controlled fashion. Road drills are a good example. They aren’t as powerful as hydraulic actuators but are cheaper and very reliable.
Each type of linear actuator has its own advantages and disadvantages, such as price, force possible, wear potential, reliability and more. There is a big drive to miniaturize linear actuators at the moment, they are becoming increasingly tiny. As materials science gets better, making smaller and smaller linear actuators is possible as they can be made to be consistent and strong, even at tiny scales.
Nothing is going to beat nature though, each cell in our bodies has millions of linear actuators, made entirely of protein and working extremely efficiently. A billion years of evolution is hard to beat, but it’s a great challenge!
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Ultra Motion provide Linear Actuator accommodate heavy loads, high bending moments and deliver long service life. For 20 years, Ultra Motion has been supplying high performance actuators to research facilities, national laboratories, and universities.