Vane pump, especially for hydraulic oil at a power assisted steering system, has grooves at the suction kidneys for an additional flow path to the pressure zone

摘要

The vane pump, with a rotor powered by a drive shaft which rotates within a lifting ring between two side plates, has radial slits within its peripheral surface for vanes with a radial sliding movement to move fluid from a suction zone to a pressure zone. The pressure zone and the suction zone are each respectively connected to at least one pressure kidney (14,15) and at least one suction kidney (18,19). A groove (26,27) under the vanes, at the suction kidneys, gives an additional flow path to the pressure zone.