Patent ID: 9181803
Filing Date: 2015-11-10
Classification: F01C,F04C

Abstract:
1. A variable capacity vane pump comprising: a pump casing including a pump chamber; a pump control ring moveable within the pump chamber about a pivot to vary the volumetric capacity of the pump; a vane pump rotor positioned within a cavity of the pump control ring and being rotatable about an axis offset from a center of the pump control ring cavity; vanes being driven by the rotor and engaging an inside surface of the pump control ring; a first control chamber between the pump casing and a first portion of the pump control ring, the first portion of the pump control ring circumferentially extending on either side of the pivot, the first control chamber operable to receive pressurized fluid to create a force to move the pump control ring to reduce the volumetric capacity of the pump; a second control chamber between the pump casing and a second portion of the pump control ring, the second control chamber operable to receive pressurized fluid to create a force to move the pump control ring to reduce the volumetric capacity of the pump; and a return spring biasing the pump control ring toward a position of maximum volumetric capacity, the return spring acting against the forces created by the pressurized fluid within the first and second control chambers.