Patent ID: 7832995
Filing Date: 2010-11-16
Classification: F01C,F04C,Y10T

Abstract:
1. A variable displacement vane pump comprising: a first body including: a second body covering a second longitudinal end of the inner space of the first body; a drive shaft supported by the first body and the second body for rotation, the drive shaft having a longitudinal axis extending in the inner space of the first body longitudinally of the cylinder portion of the first body; an adapter ring having an outer radial periphery fitted and fixed to an inner radial periphery of the cylinder portion of the first body, and having an inner radial periphery including a contact area; a cam ring mounted inside the adapter ring and supported by the adapter ring for lateral motion in contact with the contact area of the adapter ring, the cam ring and the adapter ring defining first and second fluid pressure chambers therebetween, the first fluid pressure chamber having a volumetric capacity that increases when the cam ring moves toward a first end position, the second fluid pressure chamber having a volumetric capacity that increases when the cam ring moves toward a second end position; a rotor mounted inside the cam ring and coupled to the drive shaft at least for rotation about an axis in a direction, the rotor defining an annular chamber outside thereof, the rotor including a plurality of slots arranged circumferentially at its outer radial periphery, each of the slots extending radially of the rotor; a plurality of vanes mounted in respective ones of the slots of the rotor for moving longitudinally of the slots of the rotor, the vanes extending radially of the rotor and dividing the annular chamber into a plurality of pump chambers; a suction port defined in a first section of the annular chamber in which each of the pump chambers expands with the rotation of the rotor; and a discharge port defined in a second section of the annular chamber in which each of the pump chambers contracts with the rotation of the rotor, the discharge port defining a third section of the annular chamber from the suction port to the discharge port along the direction of rotation of the rotor, the third section having a larger volumetric capacity when the cam ring is in the second end position than when the cam ring is in the first end position, wherein the adapter ring has at least in the contact area a radial thickness that gradually increases when followed longitudinally of the adapter ring from the base portion of the first body toward the second body.