VANE PUMP

摘要

This vane pump comprises: vanes which are slidably inserted in slits formed radially in the outer periphery of the rotor and which have tips capable of being in sliding contact with the cum surface of the cam ring; back pressure chambers which are formed between the slits and the base ends of the vanes and which can press the vanes toward the cam surface; back pressure grooves which can communicate with the back pressure chambers as the rotor rotates; and communication grooves which interconnect back pressure grooves adjacent to each other in the circumferential direction of the rotor. The cross-sectional passage area of the communication grooves communicating with a back pressure groove located in a suction region which is formed above the center of rotation of the rotor and in which operating fluid is sucked into the pump chamber is set to be greater than the cross-sectional passage area of the communication grooves communicating with another back pressure groove located in the other suction region formed below the center of rotation of the rotor.