VANE PUMP WITH MULTIPLE CONTROL CHAMBERS

摘要

A variable capacity vane pump includes a first control chamber between a pump casing and a first portion of a pump control ring. The first portion of the control ring circumferentially extends on either side of a pivot pin. A second control chamber is provided between the pump casing and a second portion of the pump control ring. The first and second control chambers are operable to receive pressurized fluid to create a force to move the pump control ring to reduce the volumetric capacity of the pump. A return spring biases the pump ring toward a position of maximum volumetric capacity.