VARIABLE DISPLACEMENT VANE PUMP WITH THERMO-COMPENSATION

摘要

A variable displacement vane pump has a control slide displaceable within its housing and a first control chamber and a second control chamber for receiving pressurized lubricant. A thermally adjustable control valve is provided in the housing for adjusting pump displacement based on a temperature of the lubricant. In addition to fluid communication channels in the control chambers, at least one vent port is provided in the second chamber. The control valve is configured to control pressure and fluid communication between the chambers along with the control slide. The control valve can help reduce pump displacement at lower temperatures and low engine speeds. At lower temperatures, the second control chamber can be pressurized by the first control chamber. At higher temperatures, the second control chamber can be vented through the control valve and/or the vent port, despite the position of the control slide.