Patent ID: 11268509

Abstract:
A variable lubricant vane pump includes a pump housing, a shiftable control ring, a rotatable pump rotor, a control ring preload spring which preloads and pushes the control ring into a high eccentricity direction, a hydraulic safety control chamber which moves the control ring against the control ring preload spring and which is directly and constantly pressurized with a pressurized lubricant having a pump outlet pressure, a separate hydraulic adjustment control chamber which moves the control ring against the control ring preload spring and which is selectively pressurized with the pressurized lubricant having an over-atmospheric pressure, an electric adjustment valve which selectively directs the pressurized lubricant having the over-atmospheric pressure to the separate hydraulic adjustment control chamber, and a calibrated hydraulic channel which directly connects the separate hydraulic adjustment control chamber with atmospheric pressure. An effective hydraulic cross-sectional area of the calibrated hydraulic channel is less than 5.0 mm2.