Power On! Which prime mover is right for me?

No matter the device, each faces weak spots and strong points that determine overall applicability. With the proper technologies in place, you can make ideal designs for each given application. Some may have preconceived notions about the power sources: pneumatics is fast, hydraulic is for the heavy stuff, and electronics is complicated. While often true, there are many features and benefits to each that affects your applications’ quality. Choosing the right technology will help make those great designs that move product.

Of the power sources available, one of the most common is electric. Electric power is sent to our homes, hospitals and factories, and then some type of motor turns it into motion. The motor could be a linear motor, or a rotary motor. Electric power systems offer a variety of advantages in device applications: Electric motors are great for continuous motion. An electric motor working at its designed speed is the most efficient for motion generation. When working with small forces, electric power offers very precise control over positioning and they are often very fast. They also allow for multiple stops along the motion profile. There are a number of drawbacks to an electrical system. As we mentioned before, one of the drawbacks is electrical complexity. Electronics often requires some specialized knowledge to configure, which can make it difficult to make quick repairs. Electric motors struggle with high forces, and must be designed for the maximum possible load to avoid burnouts. Other issues you may face with electronics are a large amount of heat generation when operating outside of the motor limits, as well as excessive noise.

Hydraulics power also has some limits as well as some advantages. Hydraulics is often thought of as a power house because of its excellent force generating capabilities and it has many other advantages as well. Hydraulic pumps can supply holding pressure continuously without using a large amount of energy. A hydraulic accumulator can store energy easily. This allows the pump to intermittently supply a large amount of force with a smaller sized motor than an electrical system might require. An accumulator system can result in energy savings over time and reduced noise. Hydraulics can also be controlled relatively inexpensively for simple applications with simple controllers. Like its electrical counterpart, hydraulics can be controlled very precisely by way of advanced controller. Hydraulics has been a preferred choice for applications requiring smooth acceleration and deceleration especially for movement of heavy loads. There are also a few disadvantages to using a hydraulic system: hydraulics require an oil source, and working with and maintaining oil requires some time commitment; oil is also combustible so care should be taken to prevent leaks or to use an appropriate oil. When selecting power sources, hydraulic systems can have a lot to offer.

Pneumatic power also has a lot to give as a power source, and some disadvantages as well. Compared to its hydraulic counterpart, pneumatics has “buoyancy”. Because air can be compressed (which provides its buoyancy), it has a high power density and can provide more power in a small package. This is what drives the notion that pneumatics is fast, and makes it ideal for situation where a hard movement can cause damage. This has helped pneumatics find its way into medical applications such as heart pumps, where too much power could damage tissue. Pneumatics also finds a place in the medical world because it has an advantage over hydraulic oil and electronics: standard air is not combustible, nor will it cause a spark. Bouyancy also provides a convenient application for conveyors, where two packages approaching each other will make light contact, instead of being forced into each other. Because of buoyancy, pneumatics is very forgiving and provides damping like a weak spring.


No matter the device, each faces weak spots and strong points that determine overall applicability. With the proper technologies in place, you can make ideal designs for each given application. Choosing which to use: electric motors for high precision, controlled motion, and energy efficiency; hydraulics for high forces, heavy loads and high precision; pneumatic for heavy loads, fast acceleration and a bit of forgiveness in motion; no longer needs to be a chore, and the right choice will help make those great designs that move product.