A variable displacement pump includes: a first pressure control chamber; a second pressure control chamber; a spring arranged to urge the cam ring in a second swing direction; a hydraulic pressure supply valve arranged to be opened by a predetermined hydraulic pressure, and thereby to introduce a control hydraulic pressure to the first control chamber; a connection passage formed in the housing or the cam ring, and arranged to connect the first pressure control chamber and the second pressure control chamber; and a relief circuit arranged to connect the second pressure control chamber and a low pressure side, to be opened or closed in accordance with a swing position of the cam ring, and to be closed when the cam ring is swung by a predetermined amount in the first direction.

A pump device is configured so that a first drive shaft 20 for driving a first pump element E1 and a second drive shaft 40 for driving a second pump element E2 are connected through a third drive shaft 50, and a first joint 51 and a second joint 52 are respectively connected between the first drive shaft 20 and the third drive shaft 50, and between the second drive shaft 40 and the third drive shaft 50, each of the first joint and the second joint being configured to permit a joining angle change or a change in an amount of eccentricity between the corresponding drive shafts. As a result of this configuration, a flexural deformation produced in the first and second drive shafts 20, 40 can be absorbed by means of the first and second joints 51, 52, and thus it is possible to suppress the problem of the flexural deformation of one of the first and second drive shafts 20, 40 affecting the other.

A variable displacement pump includes: an urging mechanism which includes two spring members; an electromagnetic switching valve which is arranged to connect the second control chamber and the discharge portion in an energized state, and to connect the second control chamber and the low pressure chamber in a deenergized state; and a control valve which is actuated by the pressure of the discharge portion, and which is arranged to decrease the pressure within the second control chamber when the pressure of the discharge portion becomes equal to or greater than a predetermined pressure.

A variable capacity oil pump controlling a pump discharge pressure to a two-stage characteristic includes: an electromagnetic switching valve formed to enable a switching between a state in which oil is discharged from a second control oil chamber and a state in which oil is introduced into the second control oil chamber; a pilot valve controlled by a discharge pressure by oil and a biasing force by a control spring and configured to supply a hydraulic pressure to a first control oil chamber in accordance with oil, to interrupt the supply of the hydraulic pressure, and to supply or exhaust the hydraulic pressure to or from second control oil chamber; and an intermediate passage. Oil exhausted from the first and second control oil chambers is not introduced into an inside of a control spring housing chamber in which a control spring of the pilot valve is arranged.

A variable displacement vane pump includes: a control orifice that imparts resistance to a flow of working oil discharged from pump chambers; a flow-amount control valve that operates in accordance with an upstream-downstream differential pressure of the control orifice and controls a flow amount of the working oil discharged from the pump chambers; a variable control valve that is operated by the working oil that has passed through the control orifice and controls an amount of eccentricity of a cam ring with respect to a rotor by controlling a pressure difference between a first fluid pressure chamber and a second fluid pressure chamber; and a return passage that is connected to the flow-amount control valve and circulates a part of the working oil discharged from the pump chambers through a suction passage.

A hydraulic device can include two or more rings, a rotor having a plurality of vanes, and an adjuster. The two or more rings can be rotatably mounted within the hydraulic device and arranged adjacent one another configured for relative rotation with respect to one another. The rotor can be disposed for rotation about an axis within the two or more rings and can have a plurality of circumferentially spaced slots, each slot having at least one of the plurality of vanes located therein. The plurality of vanes can be configured to be movable between a retracted position and an extended position where the plurality of vanes work a hydraulic fluid introduced adjacent to the rotor. The adjuster can be configured to translate linearly to rotatably position the two or more rings relative to one another to increase or decrease a displacement of the hydraulic fluid between the rotor and the two or more rings.

A vane fluid pump for a vehicle component has an inner rotor supported within a cam ring. A series of vanes is positioned within a series of slots in an inner rotor to define and separate a series of non-uniformly sized segmented pumping chambers to disrupt harmonics during operation to reduce pressure ripples and associated tonal noise. One chamber has a first sector angle being within a first predetermined range of a nominal value. A portion of the chambers each has a sector angle greater than the first sector angle, with an average sector angle greater than the nominal value by a second predetermined range. A remaining portion of the chambers each has a sector angle less than the first sector angle, with an average sector angle less than the nominal value by the second predetermined range.

In a variable displacement oil pump (VP1) according to the present invention, a coil spring (SP) as an urging member is arranged at a position that does not overlap a first suction port (114), a first discharge port (115) and an inlet (124a) which correspond to a suction portion when viewed from an axial direction along a drive shaft (2). Therefore, in the variable displacement oil pump (VP1), there is no risk that during pump operation, flow of oil introduced into the pump chambers 30 located in a suction region through the first suction port (114), the first discharge port (115) and the inlet (124a) corresponding to the suction portion will be interrupted by the coil spring (SP). With this, in the variable displacement oil pump (VP1), a suction resistance during the pump operation is reduced, then a suction performance of the pump can be improved.

A variable displacement lubricant pump for providing a pressurized lubricant for an internal combustion engine includes a shiftable control ring, a hydraulic control chamber which directly actuates the control ring, a pump rotor comprising a plurality of slidable vanes which rotate in the control ring, a control chamber wall, a temperature control opening arranged in the control chamber wall, and a temperature control valve which connects or disconnects the temperature control opening to an atmospheric pressure. The temperature control valve comprises a valve plunger which is axially shiftable so as to block or leave open a lubricant passage, and a first bimetal actuator sheet which directly actuates the valve plunger. The first bimetal actuator sheet comprises a first switching temperature. The valve plunger is in an open position if a lubricant temperature exceeds the first switching temperature.

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.