When safe, reliable power is necessary, air motors can easily
generate torque and rotational motion from compressed air. A
mention of motors in an industrial setting may bring to mind the
typical electric motor. But system designers should also be
aware of the many advantages of air motors over their more
famous brethren. These power-dense components provide the
engineer some interesting benefits. Air motors have higher power
density than electric motors, so they can transmit more power
from the same envelope or the same power from a smaller
envelope. This is especially true when loads must be driven at
less than the nominal speed of the electric motor — which
necessitates using an electric gearmotor or electric motor with
separate gearbox. In general, the lower the nominal speed of an
electric motor, the larger and heavier it is — a 1200-rpm
electric motor is larger, heavier, and more expensive than a
3600-rpm electric motor. An air motor designed to operate at
1200 rpm may be smaller, lighter, and less expe