Patent ID: 6896489
Filing Date: 2005-05-24
Classification: F01C,F04C

Abstract:
1. A variable displacement vane pump, comprising: a housing defining a chamber, a pump inlet through which fluid enters the housing and a pump outlet through which fluid is discharged from the housing under pressure; a containment ring or eccentric ring pivotally carried by the housing for movement between a first position and a second position and defining an opening with an internal surface; a rotor carried by the housing for rotation relative to the internal surface and having a plurality of slots extending inwardly into the rotor from an exterior of the rotor; a plurality of vanes carried by the rotor with each vane slidably received in a slot in the rotor; a first actuator responsive to application of fluid under pressure and operable to pivot the containment ring or eccentric ring in a first direction; a second actuator responsive to application of fluid under pressure and operable to pivot the containment ring or eccentric ring in a second direction; wherein control and positioning of the first and second actuators are a function of a combination of a first pressure signal and a second pressure signal taken from discrete locations separated by a degree of inherent hydraulic resistance in a downstream fluid circuit; an area defining a fluid chamber formed between the housing and containment ring or eccentric ring with fluid under pressure in the fluid chamber defining the first actuator; and a control valve responsive to the differential between the first pressure signal and the second pressure signal to selectively apply, based on engine conditions, application of fluid under pressure to either the first or second actuator based on engine conditions.