What is an Air Motor?
An air motor or pneumatic motor – is a device that converts the stored energy in compressed air into rotary mechanical energy. Much like an electric motor where the electric energy is converted into rotary mechanical energy.
What is so great about Air Motors/ Pneumatic Motors?
In a nutshell, air motors have a high power to weight ratio, they do not get damaged when loaded to stall, they are naturally fine for use in Explosive atmospheres, they do not overheat – as expanding air is naturally cooling, and they can operate at a wide range of operating speeds.
Yes they are easily reversible.
Did I mention they cost far less than an equivalent electric motor? Electric motors have none of these features naturally, they have to be specially built in if at all and at high costs.
Compressed air is increasingly ubiquitous in workspaces and it is a relatively simple matter to get an air motor connected.
Different types of Air Motors!
Depending on the mechanism on how the energy is converted, air motors can be piston-driven or vane driven, or turbine-driven.
Piston driven air motors are much like the old aircraft engines, with radial pistons where expanding air is converted into rotary motions. See pic. Piston motors tend to run slower compared to vane motors and they have higher torque and reliable starting.
Vane driven air motors rely on a set of vanes that create expanding chambers as they rotate, see pic. Again expanding air is converted into rotary motions. Vane motors operating speeds tend to be higher.
Turbine air motors depend both on on-air expansion as well as air velocity from the compressed air to generate the mechanical rotary energy.
All types of air motors are frequently mated with gearboxes to alter the torque-speed characteristics, usually to suit the application. They run very fast.
Do you need an Air Motor?
The short answer is no if there is a suitable electric motor available it is always better to simply go electric.
You need an air motor when any of the following conditions are present
- Explosive atmospheres ( Ex electric motors though available are very expensive)
- A variable load which is likely to stall the motor, such as a winch or hoist or mixers or conveyors, air motors can be stalled and re-started without any intervention. Electrics do not do this well. Download and read this full typical application guide to have a better understanding of typical air motor usage in the industry
- A requirement for instant and simple reversing. All air motors reverse instantly when the air supply is reversed.
- A need for compactness
- A need for rugged outdoor duty.
How to select the right air motor for my application
It is the best idea to contact a good supplier of air motors as it will save you time and money in experimentation. Theoretical situations and calculations are fine but very often a good dose of practicality and experience matters as much. Teryair has been helping engineers select by giving practical advice to engineers on the proper selection of motors. You can refer to our wide range of available motors and other useful resources to help in selecting your motor.