Abstract: A variable capacity vane pump has a plurality of vanes radially extendably installed in their respective slots that are arranged in a circumferential direction in a rotor, a cam ring rockably provided on a supporting surface in a pump body and forming a plurality of pump chambers at an inner circumference side of the cam ring in cooperation with the rotor and the vanes, and a seal member provided at an outer circumference side of the cam ring and defining a first hydraulic pressure chamber located at a side where a pump discharge amount increases and a second hydraulic pressure chamber located at a side where the pump discharge amount decreases in a space outside the outer circumference of the cam ring. A center of the cam ring is offset to an inlet port side from a center of a driving shaft.

Abstract: In a variable capacity vane pump, a space between adjacent vanes is 1 pitch. A line that connects a half-pitch-advanced position from an end edge of an inlet port or from an end edge of an outlet port and a driving shaft center in a no-load state is termed a port reference line. A line that connects a center of a cam ring inner circumference side and the driving shaft center when an eccentricity amount of a cam ring is a maximum is termed a high pressure cam profile reference line. A line that connects the center of the cam ring inner circumference side and the driving shaft center at a low pressure when the eccentricity amount of the cam ring is a minimum is termed a low pressure cam profile reference line. The three reference lines; the port reference line, the high pressure cam profile reference line and the low pressure cam profile reference line, is set to be substantially parallel to each other.

Abstract: A variable displacement vane pump having various construction arrangements, including a low pressure supply passage constantly connecting an inlet passage and an other of a first fluid pressure chamber and second fluid pressure chamber; a low pressure introduction port formed in the other of the pump body and the rear body, and opened in an other of the first fluid pressure chamber and the second fluid pressure chamber; and a low pressure introduction passage formed in the other of the pump body and the rear body, the low pressure introduction passage connecting the low pressure introduction port and the inlet ports.

Abstract: A variable displacement pump including a rotor, a plurality of vanes, a swingable cam ring, a suction port and a discharge port, wherein a dynamic radius of the vane which extends from a center of the rotor to a leading edge of the vane is gradually decreased in a closed section that is defined between a terminal end of the suction port and an initial end of the discharge port, along with rotation of the rotor, and a port timing defined as a position of the terminal end of the suction port or a position of the initial end of the discharge port with respect to a rotational position of the vane varies along with a swing motion of the cam ring.

Abstract: A variable displacement vane pump includes a rotor, a swingable annular cam ring receiving therein the rotor, a pump body encasing the cam ring and rotor, and a pressure plate which is disposed between an end wall of the pump body and the rotor and which includes a backup surface and a sliding surface formed with an inlet port, an outlet port and a backpressure groove. The vane pump further includes a seal member which is provided between the backup surface of the pressure plate and the end wall of the pump body, and which includes an inlet-side segment extending on the radial inner side of the inlet port and the radial outer side of the backpressure groove, and an outlet-side segment extending on the radial outer side of the outlet port.

Abstract: In a variable capacity vane pump, a space between adjacent vanes is 1 pitch. A line that connects a half-pitch-advanced position from an end edge of an inlet port or from an end edge of an outlet port and a driving shaft center in a no-load state is termed a port reference line. A line that connects a center of a cam ring inner circumference side and the driving shaft center when an eccentricity amount of a cam ring is a maximum is termed a high pressure cam profile reference line. A line that connects the center of the cam ring inner circumference side and the driving shaft center at a low pressure when the eccentricity amount of the cam ring is a minimum is termed a low pressure cam profile reference line. The three reference lines; the port reference line, the high pressure cam profile reference line and the low pressure cam profile reference line, is set to be substantially parallel to each other.

Abstract: A variable displacement vane pump having various construction arrangements, including a low pressure supply passage constantly connecting an inlet passage and an other of a first fluid pressure chamber and second fluid pressure chamber; a low pressure introduction port formed in the other of the pump body and the rear body, and opened in an other of the first fluid pressure chamber and the second fluid pressure chamber; and a low pressure introduction passage formed in the other of the pump body and the rear body, the low pressure introduction passage connecting the low pressure introduction port and the inlet ports.

Abstract: A variable displacement vane pump includes a pump body, a rotor, an annular cam ring, a rear body closing the pump body, a low pressure supply passage constantly connecting the inlet passage and the other of the first fluid pressure chamber and the second fluid pressure chamber, a low pressure introduction port formed in the other of the pressure plate and the rear body, and opened in the other of the first fluid pressure chamber and the second fluid pressure chamber, and a low pressure introduction passage formed in the other of the pressure plate and the rear body, the low pressure introduction passage connecting the low pressure introduction port and the inlet side vane back pressure grooves.

Abstract: A variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable around a swing fulcrum, first and second support members on opposite axial sides of the cam ring, a suction port and a discharge port disposed on at least one of the support members, a seal dividing a space on an outer circumferential side of the cam ring into a first fluid pressure chamber defined in a direction in which the cam ring is swung to cause increase in a flow rate of a working fluid discharged, and a second fluid pressure chamber defined in a direction in which the cam ring is swung to cause decrease in the flow rate of the working fluid discharged, and a plunger biasing the cam ring from a side of the second fluid pressure chamber toward a side of the first fluid pressure chamber.

Abstract: A variable capacity vane pump has a plurality of vanes radially extendably installed in their respective slots that are arranged in a circumferential direction in a rotor, a cam ring rockably provided on a supporting surface in a pump body and forming a plurality of pump chambers at an inner circumference side of the cam ring in cooperation with the rotor and the vanes, and a seal member provided at an outer circumference side of the cam ring and defining a first hydraulic pressure chamber located at a side where a pump discharge amount increases and a second hydraulic pressure chamber located at a side where the pump discharge amount decreases in a space outside the outer circumference of the cam ring. A center of the cam ring is offset to an inlet port side from a center of a driving shaft.

Abstract: A variable displacement vane pump includes a rotor, a swingable annular cam ring receiving therein the rotor, a pump body encasing the cam ring and rotor, and a pressure plate which is disposed between an end wall of the pump body and the rotor and which includes a backup surface and a sliding surface formed with an inlet port, an outlet port and a backpressure groove. The vane pump further includes a seal member which is provided between the backup surface of the pressure plate and the end wall of the pump body, and which includes an inlet-side segment extending on the radial inner side of the inlet port and the radial outer side of the backpressure groove, and an outlet-side segment extending on the radial outer side of the outlet port.

Abstract: A variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable on a swing support surface, first and second plate members on opposite sides of the cam ring, a suction port and a discharge port on a side of at least one of the first and second plate members, a seal cooperating with the swing support surface to divide a space on an outer circumferential side of the cam ring into first and second fluid pressure chambers, a fluid pressure control valve, a stop disposed on the pump body on a side of the first fluid pressure chamber and restricting a swing movement of the cam ring, and a detent disposed between the cam ring and the pump body on a side of the second fluid pressure chamber and preventing a rotational movement of the cam ring around the driving shaft.

Abstract: A variable displacement vane pump includes a pump body, a rotor, an annular cam ring, a rear body closing the pump body, a low pressure supply passage constantly connecting the inlet passage and the other of the first fluid pressure chamber and the second fluid pressure chamber, a low pressure introduction port formed in the other of the pressure plate and the rear body, and opened in the other of the first fluid pressure chamber and the second fluid pressure chamber, and a low pressure introduction passage formed in the other of the pressure plate and the rear body, the low pressure introduction passage connecting the low pressure introduction port and the inlet side vane back pressure grooves.

Abstract: A variable displacement vane pump has a pump body, a driving shaft rotatably supported by the pump body, a rotor rotatably driven by the driving shaft, a plurality of vanes radially extendably installed in respective slots arranged in a circumferential direction in the rotor, a cam ring rockably provided inside the pump body and forming a plurality of pump chambers at an inner circumference side of the cam ring in cooperation with the rotor and the vanes. At an outer circumference side of the cam ring inside the pump body, a seal member is provided and defines a first hydraulic pressure chamber located at a side where a pump discharge amount increases and a second hydraulic pressure chamber located at a side where the pump discharge amount decreases. Then, a control valve controls only a pressure of the second hydraulic pressure chamber.

Abstract: A variable displacement vane pump includes: a cam ring defining first and second fluid pressure chambers on both sides thereof; and a rotor mounted inside the cam ring, the rotor defining an annular chamber outside thereof. Arranged outside of the rotor, vanes divide the annular chamber into a plurality of pump chambers. A suction port is defined in a section of the annular chamber in which each of the pump chambers expands with the rotation of the rotor, while a discharge port is defined in a section of the annular chamber in which each of the pump chambers contracts with the rotation of the rotor. A first fluid passage is connected to one of the first and second fluid pressure chambers. A second fluid passage is connected to one of the suction port and the discharge port. An electromagnetic valve controls fluid communication between the first and second fluid passages.

Abstract: A variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable around a swing fulcrum, first and second support members on opposite axial sides of the cam ring, a suction port and a discharge port disposed on at least one of the support members, a seal dividing a space on an outer circumferential side of the cam ring into a first fluid pressure chamber defined in a direction in which the cam ring is swung to cause increase in a flow rate of a working fluid discharged, and a second fluid pressure chamber defined in a direction in which the cam ring is swung to cause decrease in the flow rate of the working fluid discharged, and a plunger biasing the cam ring from a side of the second fluid pressure chamber toward a side of the first fluid pressure chamber.

Abstract: A cam case 23 is provided which swingably supports a cam ring 34 for forming a pump chamber 36 from a rotor in a state in which the rotor 33 having a vane 33a is moved to an eccentric position such that a swingable pin 35 axially disposed is used as a fulcrum. A pump body is formed adjacent to the two axial ends of the cam case. Moreover, a front body 21 and a rear body 22 for rotatively supporting a rotational shaft 40 of the rotor are disposed. As one of locating means for locating the two bodies and the cam case when an assembling process is performed, the swingable pin is employed. As another locating means, at least one of joining means for integrally connecting the two bodies and the cam case is a reamer bolt 45A.

Abstract: To restrain the swinging of a movable displaceable cam ring and a spool of a control valve and to suppress pulsation on the discharge side of a variable displacement pump. In the variable displacement pump, a variable metering orifice (40) is provided midway in discharge-side passages (24, 29, 43, 44, 45) extending from a pump chamber. A spool-type control valve (30) is operated with the fluid pressure on the upstream and downstream sides of the orifice to control the fluid pressure supplied to fluid-pressure chambers around the cam ring in accordance with the flow rate of the fluid discharged from the pump chamber. A single or multistage throttle portion including throttles (50, 51, 52) is provided in at least one of fluid passages (46, 47) for communicating the upstream side of the orifice to one chamber of the valve, and fluid passages (35, 19b) for communicating the one chamber to the first fluid-pressure chamber as the valve operates.