Vane pump

Abstract

A vane pump includes an annular concave portion formed in an outer circumferential surface of the rotor, both side surfaces are inclined so as to approach each other towards a bottom surface.

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 having an inner circumference cam face with which tip-end portions of the plurality of vanes are brought into sliding contact as the rotor rotates;   a first side member and a second side member arranged so as to sandwich the rotor and the cam ring;   a pump chamber partitioned by the rotor, the cam ring, the adjacent vanes, the first side member, and the second side member;   a suction port configured to guide working fluid to the pump chamber; and   an annular concave portion formed in an outer circumferential surface of the rotor, wherein   both side surfaces of the concave portion are inclined so as to approach each other towards a bottom surface.   
     
     
         2 . The vane pump according to  claim 1 , wherein
 the suction port is a cut-out portion formed in at least one of an end surface of the cam ring in contact with the first side member and an end surface of the cam ring in contact with the second side member, the cut-out portion being configured such that an inner circumferential surface of the cam ring and an outer circumferential surface of the cam ring are communicated, and   a side surface of the concave portion on a side of an end surface of the rotor is formed at a position facing the cut-out portion.   
     
     
         3 . The vane pump according to  claim 1 , wherein
 the bottom surface of the concave portion is formed of a concave curved surface.   
     
     
         4 . The vane pump according to  claim 1 , wherein
 the rotor includes two concave portions and an annular ridge portion formed between the two concave portions, the annular ridge portion being configured to project in the radial direction from the outer circumferential surface of the rotor.