초록 ▼

A variable displacement vane pump includes a rotor, vanes, a cam ring, pump chambers, a suction port, a discharge port, back pressure chambers, a plate that has a sliding contact surface and a penetrating hole, a suction-side back pressure port being configured to guide the working fluid in the suct

A variable displacement vane pump includes a rotor, vanes, a cam ring, pump chambers, a suction port, a discharge port, back pressure chambers, a plate that has a sliding contact surface and a penetrating hole, a suction-side back pressure port being configured to guide the working fluid in the suction port to the back pressure chambers in a suction section, a discharge-side back pressure port being configured to guide the working fluid that is discharged from the discharge port to the back pressure chambers in a discharge section, an additional groove provided on the sliding contact surface so as to extend from between the discharge-side back pressure port and the penetrating hole to between the suction-side back pressure port and the penetrating hole, and a connection groove that communicates the additional groove with the suction-side back pressure port.

대표청구항 ▼

1. A variable displacement vane pump used as a fluid pressure source comprising: a rotor that is linked to a shaft rotationally driven by motive force from a motive-power source;a plurality of slits formed in a radiating pattern so as to open at an outer circumference of the rotor;vanes respectively

1. A variable displacement vane pump used as a fluid pressure source comprising: a rotor that is linked to a shaft rotationally driven by motive force from a motive-power source;a plurality of slits formed in a radiating pattern so as to open at an outer circumference of the rotor;vanes respectively received in the slits in a freely slidable manner;a cam ring that has an inner circumferential cam face with which tip end portions of the vanes are brought into sliding contact, the cam ring is made eccentric to a center of the rotor and the tip end portions being end portions of the vanes in direction projecting from the slits;pump chambers defined by the rotor, the cam ring, and the adjacent vanes;a suction port configured to guide working fluid that is to be sucked into the pump chambers;a discharge port configured to guide the working fluid that is discharged from the pump chambers;back pressure chambers formed in the slits and partitioned by base-end portions of the vanes, the base-end portions being end portions at the opposite side from the tip end portions;a plate that has a sliding contact surface and a penetrating hole, the sliding contact surface being in sliding contact with a side surface of the rotor and the penetrating hole being configured such that the shaft is inserted thereinto;a suction-side back pressure port formed on an outer circumferential side of the penetrating hole on the sliding contact surface, the suction-side back pressure port being configured to guide the working fluid in the suction port to the back pressure chambers in a suction section in which the pump chambers are in communication with the suction port;a discharge-side back pressure port formed on an outer circumferential side of the penetrating hole on the sliding contact surface, the discharge-side back pressure port being configured to guide the working fluid that is discharged from the discharge port to the back pressure chambers in a discharge section in which the pump chambers are in communication with the discharge port;both ends of the suction-side back pressure port and the discharge-side back pressure port are separated from each other, without being communicated;an additional groove provided on the sliding contact surface so as to extend from between the discharge-side back pressure port and the penetrating hole to between the suction-side back pressure port and the penetrating hole; anda connection groove that communicates the additional groove with the suction-side back pressure port. 2. The variable displacement vane pump according to claim 1, wherein a cross-sectional area of the connection groove is smaller than a cross-sectional area of the additional groove. 3. The variable displacement vane pump according to claim 1, wherein the additional groove is formed so as to have a ring shape over the entire outer circumferential side of the penetrating hole on the sliding contact surface. 4. The variable displacement vane pump according to claim 1, wherein the plate is provided on at least one of side surfaces of the rotor.