Abstract: A lubrication system for a power transmission device includes a variable displacement vane pump including a moveable control ring for varying the displacement of the pump. A linear actuator directly acts on the control ring for moving the control ring between maximum and minimum pump displacement positions. The linear actuator includes an electric motor for rotating a drive member. The drive member engages a driven actuator shaft to cause linear translation of the actuator shaft in response to rotation of the drive member. A control system includes a controller for signaling the actuator to extend or retract the actuator shaft to vary the pump displacement.

Abstract: A novel crescent gear pump and pump rotor set for a crescent gear pump. The rotor set includes an outer rotor with teeth having a composite profile formed over the portion adjacent their root to conform to a circular arc and formed over the portion adjacent their tip to conform to a hypocycloid arc. The unique shape allows for increased volumetric capacity of the rotor set, when compared to trochoidal rotor sets of the same size. Further, operating noise is reduced, as are pulsations in the output of the pump when compared to the same pump with a trochoidal rotor set.

Abstract: A lubrication system for a power transmission device includes a variable displacement vane pump including a moveable control ring for varying the displacement of the pump. A linear actuator directly acts on the control ring for moving the control ring between maximum and minimum pump displacement positions. The linear actuator includes an electric motor for rotating a drive member. The drive member engages a driven actuator shaft to cause linear translation of the actuator shaft in response to rotation of the drive member. A control system includes a controller for signaling the actuator to extend or retract the actuator shaft to vary the pump displacement.

Abstract: A novel crescent gear pump and pump rotor set for a crescent gear pump. The rotor set includes an outer rotor with teeth having a composite profile formed over the portion adjacent their root to conform to a circular arc and formed over the portion adjacent their tip to conform to a hypocycloid arc. The unique shape allows for increased volumetric capacity of the rotor set, when compared to trochoidal rotor sets of the same size. Further, operating noise is reduced, as are pulsations in the output of the pump when compared to the same pump with a trochoidal rotor set.