VANE PUMP

摘要

A vane pump has a side plate provided at the side of a cam ring and having discharge ports (21, 34) opened in it; a rotor rotatably received in the cam ring and rotated by a drive shaft; and vanes projectably held, in a circumferential direction of the cam ring, in slots formed in radial directions in the outer periphery of the rotor. Fine grooves (40, 40) communicating with the discharge ports are formed in the inside face sliding on the rotor of the side plate, and the fine grooves are formed so as to start from the discharge ports and to be gradually reduced in width in a opposite direction to the rotational direction of the rotor. Tip portions (40b, 40b) of the fine grooves are formed so that they are directed toward more inward than a rotational locus line (X) of each of the vanes which locus line passes through base end portions (40a, 40a) of the fine grooves.