Abstract: In an adjustable vane-type pump, there is provided an idle stroke adjusting device for variation of the pre-compression. The device comprises a laterally arranged adjustable supporting element having a substantially planar supporting surface bearing against the curved supporting surface area of the cam ring. The plane of the supporting surface of the supporting element is inclined relative to the plane which is defined by the joint axis of the delivery-limiting device and the pressure-control device as well as by the rotor axis. The curved supporting surface area of the cam ring is formed by the cylindrical peripheral surface of the cam ring. By using this extremely straightforward idle stroke adjusting device, wherein the idle stroke adjustment changes in response to the output pressure and the flow rate, respectively, a more favorable noise emission over the entire operating range of the pump is accomplished.

Abstract: In a vane pump having a casing, an annular rotor rotatably disposed in the casing, a plurality of vanes longitudinally movably carried by the rotor, and a cam ring eccentrically disposed about the rotor with its cylindrical inner surface slidably contacting with the leading ends of the vanes, the cam ring having at the diametrically opposed portions thereof inlet and outlet ports which face in the same direction, there is proposed a measure in which a groove is formed in the cam ring near the inlet port and faces in the same direction as the inlet and outlet ports, and in which the groove is connected to the outlet port for balancing the cam ring.

Abstract: A pump has a stator formed with intake and output ports connected to the lubricating system of an internal-combustion engine of an automotive vehicle for flow therethrough, a rotor in the stator positively driven by the engine output, an adjustment element operatively connected to the stator and rotor and displaceable between one end position corresponding to relatively great flow through the pump when the rotor is rotated by the output and an opposite end position corresponding to substantially no flow through the pump when the rotor is rotated by the engine output, and a biasing unit for urging the adjustment element toward the one end position with a fixed force. An abutment unit is connected to the adjustment element of the pump for limiting displacement of same from an intermediate position between its end positions into the opposite end position corresponding to no flow through the pump.

Abstract: A variable output vane pump for use with an automotive automatic transmission. At least one pressure chamber is formed between the circular bore of a housing and the outer circumference of a ring by means of at least one seal pin which is fitted in the axial groove formed in the ring circumference and which is opened in the housing bore. The ring is urged by the action of a spring, which is fitted in the housing, in a direction opposite to the pressure to be built up by the pressure chamber. An elastic member is fitted in the bottom of the axial groove to urge the seal pin both toward the housing bore and at the same time toward one of the side walls of the axial groove. The urging direction of the elastic member and a tangential line, on which the seal pin is tangential to the housing bore, are angularly positioned at an acute angle with respect to each other.

Abstract: There is provided a control device for a vane type variable displacement pump. The control device eliminates the need of a hydraulic cylinder to control the eccentricity of a cam ring of the vane pump. A pressure difference between a second chamber and a high pressure side of the pump first chamber on a low-pressure side of the vane pump is utilized to determine the eccentricity of the cam ring. A regulator valve is connected to the first chamber and with the second chamber in order to allow or prevent communication between the two chambers. A spring is also provided to always force the cam ring in a direction so as to make the eccentricity of the cam ring larger.

Abstract: A vane type pump with a variable capacity for power steering devices is provided with a movable ring received and radially movable in a closed cylindrical bore of a pump housing. A spring acts on the movable ring to deflect the axis of the movable ring from the axis of a rotor, which is rotated to move vanes along an internal bore of the movable ring. A sealing pin and a valve element are provided at diametrically opposite sides of the movable ring and define first and second pressure chambers around the movable ring. The first pressure chamber receives pressurized fluid from a part of the internal bore of the movable ring and conducts the pressurized fluid into the second pressure chamber through a throttle, which is defined by the valve element and a part of a circumferential external surface of the movable ring. The throttle generates a pressure difference between the first and second pressure chambers, and the pressure difference acts on the movable ring to move the same against the force of the spring.

Abstract: A control ring in sliding contact with the radially outer ends of fluid displacing vanes on a pump rotor, is angularly adjustable about a pivot formation in a pump housing on one radial side of the rotor opposite a limited sealing surface on the housing having a center of curvature on the rotor axis. A sealing element pivotally mounted on the control ring is biased into wiping contact with the sealing surface to divide the pump housing into inlet and outlet pressure chambers.

Abstract: A variable displacement vane type pump having a pivotally mounted ring member controllable to vary the eccentricity between the rotor and the ring thus controlling the pump displacement. The ring is positioned on the pivot such that the center thereof is always located in one quadrant relative to axes through the pivot point and the center of the pump rotor to continually maintain the net ring reaction force, due to internal pressure, directed to one side of the pivot connection in opposition to the displacement control pressure, which is impressed on a portion of the outer surface of the ring, whereby control stability throughout the displacement range is improved.

Abstract: An internal-external gear pump wherein the fluid displacement thereof is variable. The internal gear is rotatably driven by a drive shaft about a fixed axis and the external gear is rotatably driven by the internal gear about a controlled movable axis eccentric to the fixed axis. Movement of the external gear axis causes the eccentricity between the internal and external gear axes to vary, thereby resulting in a change in the depth of gear tooth mesh such that the volume of fluid displaced by the meshing teeth is varied. The position of the external gear axis is established by a control ring which rotatably supports the external gear, and is mounted in a stationary housing so as to be rotatably positionable within arcuate limits about a fixed axis eccentric to both the axes of the internal and external gears.