Pneumatic Rotary Actuators

Pneumatic rotary actuators use pressurized gas to produce a rotary motion or torque. The motion produced may be continuous, as for an electric motor, or intermittent. The actuator is comprised of a piston, a cylinder, and valves or ports. A seal covers the piston and traps air in the upper part of the cylinder, creating pressure that forces the seal downward. The seal then moves the piston and valve stem below, creating energy to move the rotors. The size of the output pressure depends on the size of the piston. Larger pistons are good if air supply is low because they create more pressure than smaller pistons.