Abstract: A pump device includes a pump, a flow control valve having a spool that returns a part of working fluid discharged from the pump to a suction side, and a differential pressure adjusting device that adjusts a differential pressure acting on both end portions of the spool to a target differential pressure, and the differential pressure adjusting device includes a pressure regulating chamber that communicates with a second fluid pressure chamber and a pilot chamber into which pressure in the discharge channel is guided: and a pressure in the pressure regulating chamber is adjusted such that a differential pressure between the pressure in the pressure regulating chamber and a pressure in the pilot chamber becomes the target differential pressure.

Abstract: A vane pump used as a fluid pressure source includes: a rotor that is rotationally driven; a plurality of vanes that are inserted into the rotor in a freely slidable manner; a cam ring at which tip-end portions of the vanes slides as the rotor rotates; a pump chamber that is defined between the adjacent vanes; a suction port that guides working fluid to the pump chamber; a discharge port through which the working fluid discharged from the pump chamber is guided; a groove-like notch that extends from an opening edge of the discharge port in an opposite direction from rotation direction of the rotor, and the notch has a gradient-changing portion at which a rate of change of opening area is decreased in the rotation direction of the rotor.

Abstract: A variable capacity type vane pump with a first fluid pressure chamber and a second fluid pressure chamber provided at opposite sides of a pivot point of a cam ring includes a control valve for controlling a drive pressure of working fluid introduced from a pump chamber to the second fluid pressure chamber, a suction pressure of the working fluid sucked into the pump chamber is constantly introduced to the first fluid pressure chamber, and the cam ring pivots in a direction to decrease a discharge capacity due to a pressure in the pump chamber acting on an inner peripheral cam surface during an operation to reduce the drive pressure, whereas the cam ring pivots in a direction to increase the discharge capacity during an operation to increase the drive pressure.

Abstract: In a variable capacity vane pump in which a discharge capacity of a pump chamber is varied by varying an amount of eccentricity of a cam ring relative to a rotor, a port inner wall surface that extends around an inner peripheral cam surface of the cam ring when the cam ring moves in a direction for increasing the amount of eccentricity of the cam ring relative to the rotor is formed on an intake port.

Abstract: A vane pump includes a rotor, slits which are radially formed in the rotor, vanes which slidably project from the slits, vane back pressure chambers which are defined between the base end parts of the vanes and the slits, a cam ring with which the tip parts of the vanes slide in contact, a pump chamber which is defined among the cam ring, the rotor and adjacent vanes, a vane ring which faces the base end parts of the vanes, a vane ring housing chamber on which one end of each slit is open and in which the vane ring is housed, and vane ring opposite pressure chambers on which the other ends of the slits are open and which cause a fluid pressure to act in a direction to push the rotor toward the vane ring.

Abstract: A variable displacement vane pump includes a rotor, vanes, a cam ring, pump chambers, a suction port, a discharge port, back pressure chambers, a plate that has a sliding contact surface and a penetrating hole, a suction-side back pressure port being configured to guide the working fluid in the suction port to the back pressure chambers in a suction section, a discharge-side back pressure port being configured to guide the working fluid that is discharged from the discharge port to the back pressure chambers in a discharge section, an additional groove provided on the sliding contact surface so as to extend from between the discharge-side back pressure port and the penetrating hole to between the suction-side back pressure port and the penetrating hole, and a connection groove that communicates the additional groove with the suction-side back pressure port.

Abstract: A vane pump including a cam ring, a rotor, slits formed in the rotor, vanes inserted slidably into the slits, pump chambers defined by the vanes, back pressure chambers defined between respective base end portions of the vanes and the slits, back pressure grooves capable of communicating with the back pressure chambers as the rotor rotates, and connecting grooves connecting back pressure grooves that are adjacent in a circumferential direction of the rotor to each other, wherein a connecting groove that communicates with a back pressure groove positioned in a suction region formed above a rotary center of the rotor so as to suction a working fluid into the pump chambers is formed to have a larger passage sectional area than a connecting groove that communicates with another back pressure groove positioned in another suction region formed below the rotary center of the rotor.

Abstract: A vane pump includes a rotor, vanes, pump chambers, a suction port, and a discharge port. The side member has a first transition section and a second transition section. The first transition section is a section from an end point of the suction port to a start point of the discharge port. The second transition section is a section from an end point of the discharge port to a start point of the suction port. An angle between the start point and the end point of the suction port is set such that a pressurizing timing is offset from a depressurizing timing. The pressurizing timing is a timing at which one pump chamber starts to communicate with the discharge port from the first transition section, and the depressurizing timing is a timing at which another pump chamber starts to communicate with the suction port from the second transition section.

Abstract: A vane pump includes: a rotor; vanes; a cam ring; pump chambers; a suction port; a discharge port; back-pressure chambers; a discharge-side back pressure port configured to guide working fluid that is discharged from the discharge port to the back-pressure chambers; and suction-side back pressure ports configured to guide the working fluid to the back-pressure chambers. The suction-side back pressure ports are formed to be divided into a low-pressure port and a high-pressure port, the low-pressure port being configured to guide the working fluid in the suction port to the back-pressure chambers, and the high-pressure port being configured to guide the working fluid that is discharged from the discharge port to the back-pressure chambers. The high-pressure port is arranged at the forward-side of the low-pressure port in rotating direction of the rotor.

Abstract: A variable displacement vane pump includes: a rotor to be rotatively driven; a plurality of vanes slidably housed in the rotor; a cam ring allowed of eccentric with respect to a center of the rotor, the cam ring having an inner circumferential cam surface in sliding contact with a distal end portion of the vane; a pump chamber defined by the adjacent vanes, the rotor, and the cam ring; a suction port to guide hydraulic fluid to be suctioned to the pump chamber; and a discharge port to guide hydraulic fluid to be discharged from the pump chamber. An outer circumference of an opening portion of the suction port is formed so as to be positioned along the inner circumferential cam surface of the cam ring or at an outside of the inner circumferential cam surface regardless of eccentricity of the cam ring with respect to the rotor.

Abstract: A variable displacement vane pump includes: an adapter ring (a cam ring housing member) that defines a first fluid pressure chamber and a second fluid pressure chamber relative to an outer periphery of a cam ring, the cam ring being moved relative to a rotor by a differential pressure between the first fluid pressure chamber and the second fluid pressure chamber; a seal housing groove formed in an inner periphery of the adapter ring; and a slipper seal which is inserted into the seal housing groove and with which an outer periphery of the cam ring comes into sliding contact when the cam ring moves, whereby the slipper seal partitions the first fluid pressure chamber from the second fluid pressure chamber, wherein the slipper seal is formed in a thin plate shape having a square cross-section.

Abstract: In a variable capacity type vane pump in which a cam ring pivots, a discharge port is so formed that an absolute value of a difference between a discharge port start edge line inclination angle and a discharge port end edge line inclination angle is larger than a vane angle.

Abstract: A variable capacity type vane pump with a first fluid pressure chamber and a second fluid pressure chamber provided at opposite sides of a pivot point of a cam ring includes a control valve for controlling a drive pressure of working fluid introduced from a pump chamber to the second fluid pressure chamber, a suction pressure of the working fluid sucked into the pump chamber is constantly introduced to the first fluid pressure chamber, and the cam ring pivots in a direction to decrease a discharge capacity due to a pressure in the pump chamber acting on an inner peripheral cam surface during an operation to reduce the drive pressure, whereas the cam ring pivots in a direction to increase the discharge capacity during an operation to increase the drive pressure.

Abstract: In a variable capacity vane pump in which a discharge capacity of a pump chamber is varied by varying an amount of eccentricity of a cam ring relative to a rotor, a port inner wall surface that extends around an inner peripheral cam surface of the cam ring when the cam ring moves in a direction for increasing the amount of eccentricity of the cam ring relative to the rotor is formed on an intake port.

Abstract: A vane pump is used as a fluid pressure supply source and includes a rotor which is driven and rotated, a plurality of slits which are radially formed in the rotor, a plurality of vanes which slidably project from the slits, a cam ring with which tip parts of the vanes slide in contact as the rotor rotates, a pump chamber which is defined between the cam ring and adjacent ones of the vanes, a plurality of discharge ports which introduce working fluid discharged from the pump chamber contracting as the rotor rotates, a discharge passage which causes the working fluid introduced from the discharge ports to join, and a check valve which is opened for a flow of the working fluid discharged from one discharge port to the discharge passage.

Abstract: A vane pump includes a rotor, slits which are radially formed in the rotor, vanes which slidably project from the slits, vane back pressure chambers which are defined between the base end parts of the vanes and the slits, a cam ring with which the tip parts of the vanes slide in contact, a pump chamber which is defined among the cam ring, the rotor and adjacent vanes, a vane ring which faces the base end parts of the vanes, a vane ring housing chamber on which one end of each slit is open and in which the vane ring is housed, and vane ring opposite pressure chambers on which the other ends of the slits are open and which cause a fluid pressure to act in a direction to push the rotor toward the vane ring.

Abstract: An electric oil pump includes an electric motor and an oil pump that is driven by the motive power from an electric motor, wherein; the oil pump has an introducing channel that guides a drain oil that has leaked from an interior of the oil pump to an interior of the electric motor; and the electric motor has a discharging channel that discharges the drain oil that has been guided to the interior of the electric motor to a tank.

Abstract: A solenoid actuator (1) attached to hydraulic equipment comprises a shaft (5) connected to the hydraulic equipment, a plunger (4) fixed to the shaft (5), a coil (12) which magnetically drives the plunger (4), and a first bearing (7) and a second bearing (8) supporting the shaft (5) on either sides of the plunger (4). A plunger front chamber (74) is formed between the first bearing (7) and the plunger (4), and a plunger rear chamber (75) is formed between the plunger (4) and the second bearing (8). By providing a plunger exterior oil passage (63) on the outside of the plunger (4) to connect the plunger front chamber (74) to the plunger rear chamber (75), working oil flows through the plunger exterior oil passage (63) every time the plunger (4) strokes, thereby preventing a deposit of contaminant on the plunger (4) without increasing a stroke resistance of the plunger (4).

Abstract: A variable displacement vane pump includes a first and a second fluid pressure chamber (31,32) where the cam ring (4) is made eccentric to the rotor (2) by a pressure difference between the first and the second fluid pressure chamber (31,32), a control valve (21) for controlling a pressure of the first and the second fluid pressure chamber (31,32) so that an eccentric amount of the cam ring (4) is reduced to be small with an increase in a rotation speed of the rotor (2), a pressure applying section (36) for applying a pressure to the cam ring (4) in a direction of increasing the eccentric amount all the time, and a cam ring movement restricting portion (12) for defining a minimum eccentric amount of the cam ring (4) by restricting the movement of the cam ring (4) in a direction of decreasing the eccentric amount.

Abstract: A variable capacity vane pump (100) has a pump housing (10) having a high-load bearing part (10a) on which a higher load is exerted than another part when the pump vane pump (100) operates. A control valve (21) for varying a capacity of the vane pump (100) is provided in a valve housing (28) which is formed integrally in the pump housing (10). By arranging the valve housing (28) on the same side of the pump housing (10) as the high-load bearing part (10a) with respect to the rotation axis of the vane pump (100), the high-load bearing part (10a) can be reinforced without increasing the size of the vane pump (100).