An air motor (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. With proper using and maintenance, you can be sure that your air motor will maintain a high level of performance for many years. And it is easy to maintain an air motor. Basically, there are two key elements to pay attention to: lubrication and filtration.