The high-precision vane air motors essentially consist of a rotor with rotor shaft, housing, bearing cover, vanes, roller bearing and sealing ring. The rotor is shrunk onto the rotor shaft. The four or eight vanes move freely in the high-precision sliding slots of the rotor and are supported on the honed housing bore. There are various solutions for lamella contact pressure during start-up and at low speeds: lamella support rings, springs or rear-side pressurization. At higher speeds, the centrifugal force also supports the vane seal. Depending on the speed, the compressed air condition and the operating pressure, the vanes achieve a service life of many thousands of operating hours.