VARIABLE CAPACITY VANE PUMP WITH OUT-OF-PLANE CONTROL

摘要

Variable capacity vane pumps are provided which require less radial volume about the pump by placing the pump control mechanism out of the plane of the pump rotor. In one embodiment, the control mechanism is placed on one side of the rotor plane and is connected to the capacity adjusting element by a pin, or other suitable mechanism. In another embodiment, the control mechanism is split above and below the plane of the pump rotor, with one element of the control mechanism, such as a control spring, being located on one side of the rotor plane and another element of the control mechanism, such as a control piston, being located on the other side of the rotor plane. In yet another embodiment, two control mechanisms are provided, one on each side of the rotor plane, to provide different equilibrium operating pressures for the pump. In yet another embodiment, the element of the control mechanism which moves the capacity adjusting element to increase capacity is a chamber supplied with pressurized working fluid to urge the capacity adjusting element to reduce capacity. In this embodiment, a biasing element, such as a control spring, is located either above or below the rotor plane.