Rotary vane compressor having pressure-biased vanes

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. To avoid undue wear and abrasion between the vane tips and the compartment inner wall, the pressurized lubricant oil is fed to the vane slots at a reduced pressure while the vanes travel from the gas inlet openings to the region of the gas outlet openings, and to avoid vane chattering after discharge of the compressed gas at the gas outlet openings, the pressurized lubricant oil is fed to the vane slots at a higher pressure while the vanes travel in the region of the gas outlet openings.