Vane pump

Abstract

A vane pump includes a housing, a cam ring, a rotor, a plurality of vanes that forms a plurality of pump chambers, a side plate constituting a portion of an intake port, an intermediate plate axially adjacent to the housing and the side plate, and a cover member. A portion of a flow passage, through which a fluid flows, is constituted by a surface of the intermediate plate and at least one of the housing, the side plate, and the cover member, the surface of the intermediate plate being adjacent to the at least one of the housing, the side plate, and the cover member. A through-hole or a recessed portion is formed in the intermediate plate, and the through-hole or the recessed portion of the intermediate plate and the side plate constitute a portion of the intake port.

What is claimed is: 
     
         1 . A vane pump comprising:
 a housing;   a cam ring that is provided inside the housing and has a cam face in an inner peripheral surface of the cam ring;   a rotor that is rotatably provided on an inner periphery side of the cam ring and has a plurality of accommodation grooves extending radially inward from an outer peripheral surface of the rotor;   a plurality of vanes that is slidably accommodated in the respective accommodation grooves and circumferentially divides a space between the cam face and the outer peripheral surface of the rotor to form a plurality of pump chambers;   a side plate that is axially adjacent to the cam ring and the rotor and constitutes a portion of an intake port that is opened so as to allow a fluid to be sucked into the pump chambers;   an intermediate plate axially adjacent to the housing and the side plate; and   a cover member that is fixed to an axial end portion of the housing in a manner such that the intermediate plate is interposed between the cover member and the housing,   wherein a portion of a flow passage, through which the fluid flows, is constituted by a surface of the intermediate plate and at least one of the housing, the side plate, and the cover member, the surface of the intermediate plate being adjacent to the at least one of the housing, the side plate and the cover member, and   wherein a through-hole or a recessed portion is formed in the intermediate plate, and the through-hole or the recessed portion of the intermediate plate and the side plate constitute a portion of the intake port.   
     
     
         2 . The vane pump according to  claim 1 , wherein a portion of the intake port is constituted by the through-hole of the intermediate plate and a recessed portion that is formed in the cover member so as to communicate with the through-hole. 
     
     
         3 . The vane pump according to  claim 1 , wherein a portion of the intake port is constituted by the through-hole of the intermediate plate and an end face of the cover member. 
     
     
         4 . The vane pump according to  claim 1 , wherein a portion of the intake port is constituted by the recessed portion that is formed to be shallower than a thickness of the intermediate plate.