Abstract: A rotary vane compressor has a cylinder having an oval-shaped compartment in which is rotatably mounted a rotor. Front and rear side blocks close the opposite ends of the cylinder. A plurality of vanes are slidably mounted in slots formed around the rotor and divide the cylinder compartment into expansible working chambers. A gas inlet opening is disposed at the upstream end of each working chamber for admitting a gas to be compressed and a gas outlet opening is disposed at the downstream end of each working chamber for discharging the compressed gas. A source of pressurized lubricant oil is fed to the base of the vane slots to bias the vanes outwardly so that the vane tips slidably engage the inner wall of the cylinder compartment during rotation of the rotor.