an engine that converts the energy of compressed air into mechanical work.
A distinction is made between positive-displacement and turbine compressed-air motors, depending on the principle of operation. In positive-displacement motors, work is performed by the expansion of compressed air in the cylinders of a piston machine; in the turbine types, by the action of an air stream on the blades of a turbine (in the first case the potential energy of the compressed air is used, and in the second case the kinetic energy is used). Positive-displacement motors of the piston and rotary types are the most common.
Compressed-air motors are used to operate various tools, such as drills, wrenches, pick hammers, and grinding heads, while ensuring safe operation in areas where there is a danger of explosion from accumulations of gas or coal dust; they are also used in excessively moist media.