Direct control variable displacement vane pump
AssigneeMAGNA Powertrain AG & Co KG
InventorsPeter Krug, Vasilios B. Liavas, Gurvinder Bhogal
Life of this patent
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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.
Claims22
A lubrication system for a power transmission device, comprising:
- a variable displacement vane pump having a pivotable pump control ring for varying the displacement of the pump;
- and
- a control system operable to vary the displacement of the pump during operation of the pump to achieve an output pressure selected from a continuously variable range of output pressures from the pump which are independent from the operating speed of the pump, the control system including a linear actuator coupled to the control ring for moving the control ring between minimum and maximum pump displacement positions, the linear actuator including an electric stepper motor for bi-directionally rotating a nut threadingly engaged with an axially moveable actuator shaft and a coupler interconnecting the actuator shaft and the control ring, the coupler having multiple degrees of freedom to allow concurrent axial movement of the actuator shaft and rotation of the control ring.
A lubrication system for a power transmission device, comprising:
- a variable displacement vane pump including a moveable control ring for varying the displacement of the pump;
- a linear actuator directly acting on the control ring for moving the control ring between maximum and minimum pump displacement positions, the linear actuator including an electric motor for rotating a drive member, the drive member engaging a driven actuator shaft to cause linear translation of the actuator shaft in response to rotation of the drive member, the linear actuator further including a coupler interconnecting the actuator shaft and the control ring;
- and
- a control system including a controller for signaling the actuator to extend or retract the actuator shaft to vary the pump displacement, wherein the controller operates in an open loop control mode and is not in receipt of a signal indicative of the pressure being output by the pump.
A lubrication system for a power transmission device, comprising:
- a variable displacement vane pump including a housing containing a moveable control ring for varying the displacement of the pump;
- a linear actuator directly acting on the control ring for moving the control ring between maximum and minimum pump displacement positions, the linear actuator including an electric motor for rotating a drive member, the drive member engaging a driven actuator shaft to cause linear translation of the actuator shaft in response to rotation of the drive member, the linear actuator further including a coupler interconnecting the actuator shaft and the control ring;
- a control system including a controller for signaling the actuator to extend or retract the actuator shaft to vary the pump displacement;
- a first control chamber positioned between the housing and an outer surface of the pump control ring and being in receipt of pressurized working fluid and operable to create a force on the pump control ring to urge the pump control ring towards the position of minimum displacement;
- and
- a second control chamber positioned between the housing and the outer surface of the pump control ring and being in receipt of pressurized working fluid and operable to create a force on the pump control ring to urge the pump control ring towards the position of maximum displacement, wherein the resultant force on the pump ring approaches zero.
Dependencies are inferred from the claim text.