The vector stencils library "Pneumatic pumps and motors" contains 39 symbols of pneumatic pumps, motors and pump-motors for designing the engineering drawings of pneumatic circuits.
"A pneumatic motor or compressed air engine is a type of motor which does mechanical work by expanding compressed air. Pneumatic motors generally convert the compressed air energy to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor." [Pneumatic motor. Wikipedia]
"A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor.
Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas. Liquids are relatively incompressible; while some can be compressed, the main action of a pump is to pressurize and transport liquids." [Gas compressor. Wikipedia]
The shapes example "Design elements - Pneumatic pumps and motors" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Mechanical Engineering solution from the Engineering area of ConceptDraw Solution Park.