Vane pump

Abstract

A vane pump includes a rotor; a plurality of vanes; a cam ring; a second side plate; a suction port provided in the second side plate, the suction port being configured to guide working fluid to the pump chambers; a pump cover arranged so as to sandwich the second side plate with the cam ring; and a low-pressure chamber formed in the pump cover, the low-pressure chamber having an opening portion communicating with the suction port. The suction port is arranged so as to be shifted towards a forward side of in a rotating direction of the rotor with respect to the opening portion of the low-pressure chamber.

1 . A vane pump comprising:
 a rotor configured to be driven rotationally;   a plurality of vanes provided on the rotor so as to be able to reciprocate in a radial direction of the rotor;   a cam ring accommodating the rotor, the cam ring having an inner circumferential cam face on which tip ends of the plurality of vanes slide by rotation of the rotor;   a side member brought into contact with an end surface of the cam ring, the side member being configured to define pump chambers partitioned by the plurality of vanes between the rotor and the cam ring;   a suction port provided in the side member, the suction port being configured to guide working fluid to the pump chambers;   a cover member arranged so as to sandwich the side member with the cam ring; and   a low-pressure chamber formed in the cover member, the low-pressure chamber having an opening portion communicating with the suction port, wherein   the suction port is arranged so as to be shifted towards a forward side of in a rotating direction of the rotor with respect to the opening portion of the low-pressure chamber.   
     
     
         2 . The vane pump according to  claim 1 , wherein
 the low-pressure chamber has a wall surface for guiding the working fluid to the suction port, and   the wall surface is inclined so as to guide the working fluid from the low-pressure chamber towards a front side in the rotating direction of the rotor.   
     
     
         3 . The vane pump according to  claim 2 , wherein
 the suction port is arranged so as to be shifted towards a forward side in the rotating direction of the rotor with respect to an imaginary extended surface of the wall surface in the low-pressure chamber.   
     
     
         4 . The vane pump according to  claim 1 , wherein
 the suction port has an inner circumferential surface inclined so as to guide the working fluid from the low-pressure chamber towards a front side in the rotating direction of the rotor.