Abstract: A variable capacity pump includes a control ring moveable within a pump chamber to alter the volumetric capacity of the pump. First and second control chambers individually receive pressurized fluid to create forces to bias the control ring in a predetermined direction. A return spring urges the control ring toward a maximum volumetric capacity pump position. The control ring connects and disconnects the second control chamber from a source of pressurized fluid based on a position of the control ring. Forces from the control chambers and the spring act in combination with one another or against one another and against the spring force to establish first and second equilibrium pressures based on a pressurized or vented condition of the second control chamber.

Abstract: A variable capacity pump includes a control ring moveable within a pump chamber to alter the volumetric capacity of the pump. First and second control chambers individually receive pressurized fluid to create forces to bias the control ring in a predetermined direction. A return spring urges the control ring toward a maximum volumetric capacity pump position. The control ring connects and disconnects the second control chamber from a source of pressurized fluid based on a position of the control ring. Forces from the control chambers and the spring act in combination with one another or against one another and against the spring force to establish first and second equilibrium pressures based on a pressurized or vented condition of the second control chamber.

Abstract: A variable capacity vane pump (20) is provided having a pump control ring (44) that is moveable to alter the capacity of the pump (20). A control chamber (60) is formed between the pump casing (22) and the control ring (44). The control chamber (60) is operable to receive pressurized fluid to create a force to move the control ring (44) to reduce the volumetric capacity of the pump (20). A primary return spring (56) acts between the control ring (44) and the casing (22) to bias the control ring (44) towards a position of maximum volumetric capacity. A shaft is coupled at one end to the control ring and a second end of the shaft is positioned a predetermined distance from the casing (22). A secondary return spring (62) is mounted about the shaft and is configured to engage the control ring (44) after the control ring (44) has moved a predetermined amount. The secondary return spring (62) biases the control ring (44) towards a position of maximum volumetric capacity.

Abstract: A variable capacity vane pump for an automobile includes a pump control ring positioned within the housing to move about a pivot. A rotor is positioned within a cavity of the control ring such that a position of the control ring determines an offset between a center of the cavity and an axis of rotation of the rotor. A first control chamber is provided between the pump housing and a first outer surface of the control ring. The first outer surface is positioned on an opposite side of the control ring as the working fluid chambers within the cavity. A second control chamber is provided between the pump housing and a second outer surface of the control ring. A return spring biases the control ring toward a position of maximum volumetric capacity against the forces created by the pressurized fluid within the first and second control chambers.

Abstract: A variable capacity vane pump for an automobile includes a pump control ring positioned within the housing to move about a pivot. A rotor is positioned within a cavity of the control ring such that a position of the control ring determines an offset between a center of the cavity and an axis of rotation of the rotor. A first control chamber is provided between the pump housing and a first outer surface of the control ring. The first outer surface is positioned on an opposite side of the control ring as the working fluid chambers within the cavity. A second control chamber is provided between the pump housing and a second outer surface of the control ring. A return spring biases the control ring toward a position of maximum volumetric capacity against the forces created by the pressurized fluid within the first and second control chambers.

Abstract: A variable capacity vane pump includes a first control chamber between a pump casing and a first portion of a pump control ring. The first portion of the control ring circumferentially extends on either side of a pivot pin. A second control chamber is provided between the pump casing and a second portion of the pump control ring. The first and second control chambers are operable to receive pressurized fluid to create a force to move the pump control ring to reduce the volumetric capacity of the pump. A return spring biases the pump ring toward a position of maximum volumetric capacity.

Abstract: A variable capacity vane pump (20) is provided having a pump control ring (44) that is moveable to alter the capacity of the pump (20). A control chamber (60) is formed between the pump casing (22) and the control ring (44). The control chamber (60) is operable to receive pressurized fluid to create a force to move the control ring (44) to reduce the volumetric capacity of the pump (20). A primary return spring (56) acts between the control ring (44) and the casing (22) to bias the control ring (44) towards a position of maximum volumetric capacity. A shaft is coupled at one end to the control ring and a second end of the shaft is positioned a predetermined distance from the casing (22). A secondary return spring (62) is mounted about the shaft and is configured to engage the control ring (44) after the control ring (44) has moved a predetermined amount. The secondary return spring (62) biases the control ring (44) towards a position of maximum volumetric capacity.

Abstract: A variable displacement variable pressure vane pump system provides lubrication oil to a mechanical system. The system has a first control mechanism, which can be a control chamber directly acting on the control slider or a control chamber and control cylinder which acts on the control slider and a second control mechanism which is a control chamber and control cylinder which acts on the control slider. A control valve, operated by an engine control unit or other suitable control mechanism, selectively provides pressurized lubrication oil to the second control mechanism to allow the output of the pump system to more closely match the requirements of the mechanical system.

Abstract: A variable displacement variable pressure vane pump system provides lubrication oil to a mechanical system. The pump system includes a first control mechanism to apply a force to a control slider to counter a biasing force of a biasing spring and urge the control slider away from a position corresponding to a maximum displacement position of the pump. A second control mechanism applies a force to the control slider to alter the displacement of the pump. A control varies the supply of lubrication oil to the second control mechanism to alter the output of the pump to closely correspond to the lubrication requirements of the mechanical system.

Abstract: A variable displacement vane pump which includes an enhanced discharge port. The enhanced discharge port reduces areas of high pressure in the discharge port which would otherwise occur as the pressurized working fluid reverses its direction of flow to enter the discharge port. By reducing the areas of high pressure, the back torque on the pump rotor is reduced and the energy efficiency of the pump is enhanced. In one embodiment, the pivot for the pump control ring is located radially outwardly from a conventional location, to allow for a discharge recess to be formed in the control ring, adjacent the discharge port, and extending past the pivot to the pump outlet. In a second embodiment, the discharge recess is formed in the control ring around the pivot and a seal is provided on the control ring to inhibit leakage of pressurized working fluid past the control ring.

Abstract: A variable displacement vane pump provides a substantially constant output pressure in its regulated operation region. A longitudinal axis of the control spring is inclined, with respect to a plane through the rotational axis of a pivot and a contact point between the control ring and the control spring. The inclination reduces the length of the moment arm between the spring and the pivot when the control ring of the pump is moved from the maximum displacement position to the minimum displacement position. The reduced length moment arm offsets the increase in the moment produced by compression of the control spring is offset to achieve a substantially constant output pressure. The control spring is compressed a reduced amount during pump operation to minimize the change in output force exerted by the control spring as the control ring moves between positions.

Abstract: A traditional variable displacement vane pump must be designed to provide maximum fluid pressure and thus experiences reduced energy efficiency when the system operating conditions do not necessitate such high requirements. A variable displacement variable pressure vane pump system is provided comprising a first control mechanism, which can be a control chamber (68) directly acting on the control slider (36) or a control chamber (68) and control cylinder (44) which acts on the control slider (36) and a second control mechanism which is a control chamber (72) and control cylinder (44) which acts on the control slider (36). A control valve (76), operated by an engine control unit or other suitable control mechanism, selectively provides pressurized lubrication oil to the second control mechanism to allow the output of the pump system to more closely match the requirements of the mechanical system.

Abstract: A novel variable displacement vane pump is provided wherein pressurized working fluid is provided to a portion of the pump chamber to act on the outside of the capacity varying ring to substantially balance the force created by the high pressure working fluid inside the ring. As the resultant high pressure force acting on the pivoting pin is reduced, the movement of the displacement control ring is smoother, reducing undesirable hysteresis, the wear on the pin is reduced and the additional force required to move the ring to vary the volumetric displacement of the pump is less than would otherwise be needed, allowing the related control mechanisms to be smaller.

Abstract: A variable displacement vane pump which includes an enhanced discharge port. The enhanced discharge port reduces areas of high pressure in the discharge port which would otherwise occur as the pressurized working fluid reverses its direction of flow to enter the discharge port. By reducing the areas of high pressure, the back torque on the pump rotor is reduced and the energy efficiency of the pump is enhanced. In one embodiment, the pivot for the pump control ring is located radially outwardly from a conventional location, to allow for a discharge recess to be formed in the control ring, adjacent the discharge port, and extending past the pivot to the pump outlet. In a second embodiment, the discharge recess is formed in the control ring around the pivot and a seal is provided on the control ring to inhibit leakage of pressurized working fluid past the control ring.

Abstract: A novel variable displacement vane pump is provided wherein pressurized working fluid is provided to a portion of the pump chamber to act on the outside of the capacity varying ring to substantially balance the force created by the high pressure working fluid inside the ring. As the resultant high pressure force acting on the pivoting pin is reduced, the movement of the displacement control ring is smoother, reducing undesirable hysteresis, the wear on the pin is reduced and the additional force required to move the ring to vary the volumetric displacement of the pump is less than would otherwise be needed, allowing the related control mechanisms to be smaller.

Abstract: A variable displacement vane pump is provided which is able to achieve a substantially constant output pressure in its regulated operation region. The longitudinal axis of the control spring of the pump is inclined, with respect to a plane through the rotational axis of the pivot and the contact point between the control ring and the control spring, and this inclination results in a reduction in the length of the moment arm between the spring and the pivot when the control ring of the pump is moved from the maximum displacement position to the minimum displacement position. By reducing the length of this moment arm, the increase in the moment produced by compression of the control spring is offset, resulting in a substantially constant output pressure in the regulated operating range of the pump. The inclination further results in a reduction in the amount by which the control spring is compressed when the control ring moves from the first position to the second position.