VARIABLE DISPLACEMENT VARIABLE PRESSURE VANE PUMP SYSTEM

摘要

A traditional variable displacement vane pump must be designed to provide maximum fluid pressure and thus experiences reduced energy efficiency when the system operating conditions do not necessitate such high requirements. A variable displacement variable pressure vane pump system is provided comprising a first control mechanism, which can be a control chamber (68) directly acting on the control slider (36) or a control chamber (68) and control cylinder (44) which acts on the control slider (36) and a second control mechanism which is a control chamber (72) and control cylinder (44) which acts on the control slider (36). A control valve (76), operated by an engine control unit or other suitable control mechanism, selectively provides pressurized lubrication oil to the second control mechanism to allow the output of the pump system to more closely match the requirements of the mechanical system.