Industrial Air Motors

There are several types of air motors, with the Rotary Vane Version the most popular, followed by the Radial Piston design. At the present time, there are no known standards governing the operation of air motors in hazardous atmospheres.


Vane Air Motors are simple in design. The rotor is mounted eccentrically in the cylinder bore, and the vanes slide radially in the rotor slots as it turns. The torque at the shaft is a product of pressure, vane area exposed between the outside diameter of the rotor and the bore, and the moment arm of the vanes.

Typical Rotary Vane Motor Working


Piston Air Motors develop high torque and are well-balanced. They have three, four, or fives, providing for even torque at all speeds and smooth delivery of power with each revolution in either direction of rotation. This type of motor operates at a much slower speed than does a vane-type motor

because of the weight resulting from its reciprocating parts. Free speed is usually 3000 rpm or less. Maximum horsepower is usually developed at 1000 rpm or less. The smooth, overlapping power flow and accurate balancing of radial piston motors make them vibration-less at all speeds, a feature especially noticeable at lower speeds where maximum torque is developed.

Typical Radial Piston Motor Working