Patent ID: 9017041
Filing Date: 2015-04-28
Classification: F04C

Abstract:
1. A variable displacement lubricant pump for providing a pressurized lubricant for an internal combustion engine, the variable displacement lubricant pump comprising: a control ring which is configured to be shiftable; a first plunger which is configured to push the control ring into a high pumping volume direction; a pump rotor comprising radially slidable vanes which are configured to rotate in the control ring; a pressure control system configured to control a discharge pressure of the pressurized lubricant, the pressure control system comprising a first pressure control chamber wherein the first plunger is arranged to be axially moveable; a pump outlet port; a first pressure conduit configured to connect the pump outlet port with the first pressure control chamber; a first pressure control valve configured to control a pressure in the first pressure control chamber; an outlet opening disposed in a side wall of the first pressure control chamber; and a second pressure control valve disposed between the outlet opening and a low pressure source, the second pressure control valve being configured to control the outlet opening, wherein, the second pressure control valve is a centrifugal valve which is mechanically connected with the pump rotor and is configured to close at a high rotational speed of the pump rotor, and the outlet opening is configured to be closed by the first plunger in a low pumping volume position and to be opened in a high pumping volume position.