A first communication groove (38) extending from a start point of a discharge port (36) in a direction opposite to rotation direction of vanes (22) is formed. A first end portion (38E) of this groove is connected to the start point of the discharge port (36). When a front-side vane in a rotation direction of a driving shaft (11) is positioned at the start point of the discharge port (36), a second end portion (38S) of the groove is positioned at a rear side in the rotation direction with respect to a rear-side vane coming immediately after the front-side vane, and communicates with a suction port (35). A part of working fluid in a front-side pump chamber (27-1) can therefore be introduced into a rear-side pump chamber (27-2) that communicates with the suction port (35), thereby lessening excessive pressure increase of the front-side pump chamber (27-1) and suppressing pulsation phenomenon.

The invention relates to a vane pump for conveying liquids, in particular viscous oils, which vane pump includes: a rotor having sliding slots in which movable vanes are held and can be countersunk in relation to a rotor radius (r); a pump housing including a pump chamber, which encloses the rotor; and an inlet and an outlet, which open into the pump chamber at at least one end face of the rotor; radial elevations protruding, with respect to the sliding slots, over the circumference of the rotor, which elevations form a rotor radius (r) on either side of the vanes that can be countersunk, and radial pockets being recessed, relative to the rotor radius (r), between the radial elevations. Within the radial elevations, recesses are formed on the at least one end face of the rotor at which the inlet and the outlet open, which recesses provide rotating anticipatory control geometry for reducing pressure spikes in the vane cells.

A rotary pump includes: a housing featuring a housing inlet and a low-pressure space on a low-pressure side of the pump and featuring a housing outlet and a high-pressure space on a high-pressure side of the pump; a delivery chamber; a delivery rotor in the delivery chamber; a setting structure which can be moved in a first setting direction and, counter to the first setting direction, in a second setting direction in order to perform a setting movement which adjusts the specific delivery volume of the rotary pump; and at least a first setting chamber for charging the setting structure with a setting pressure which acts in the second setting direction, wherein the fluid pressure in the high-pressure space acts on a pressure equalization surface on the outer circumference of the setting structure resulting in an external additional force which acts on the setting structure in the first setting direction.

A rotary pump including: a pump housing including a delivery chamber, having an inlet and an outlet for a fluid; a delivery member which can be rotated about a rotational axis in the delivery chamber in order to deliver the fluid; a setting structure which can be moved translationally back and forth in the pump housing relative to the delivery member in and counter to a setting direction in order to adjust the delivery volume of the rotary pump; a setting device for generating a setting force which acts on the setting structure in the setting direction; a restoring spring for exerting a restoring force which acts on the setting structure counter to the setting direction; and an additional spring for exerting an additional force which acts on the setting structure in or counter to the setting direction.

A vane pump includes a rotor having slits, vanes received in the slits, a cam ring having an inner circumference cam face with which the vanes are brought into sliding contact, a side member, pump chambers formed by the rotor, the cam ring, and adjacent vanes, and back pressure chambers formed in the slits by the vanes. In the vane pump, the side member is provided with a back pressure opening portion opening at a sliding-contact surface in sliding contact with the rotor, the back pressure opening portion being configured to communicate with the back pressure chambers, and a protruding opening portion protruding along the rotating direction of the rotor from an end portion of the back pressure opening portion on the communication-finishing side. An inner-side inner circumferential surface of the protruding opening portion is connected to an inner-side inner circumferential surface of the back pressure opening portion.

A variable hydraulic pump include a rotor mounted on a pump housing of which a housing spring end is formed, a pivot pin, an outer ring rotatably coupled to the pivot pin and of which a ring spring end is formed, a spring mounted between the housing spring end and the ring spring end, a pressure chamber formed in the pump housing to push the outer ring, a plurality of vane provided to form a plurality of pockets, an input port to supply oil to the plurality of pockets and a discharge port to exhaust oil supplied to the plurality of pockets, wherein at the reference position of the outer ring, the angle between a first imaginary line connecting the center of the rotor and the pivot pin and a second imaginary line connecting the ring spring end and the pivot pin is 0 to 10 degrees.

A driving force distributing device includes a single pump for supplying control hydraulic pressure to each of first and second hydraulic clutches, an electric motor for driving the pump, a flow rate variable mechanism for changing a ratio of flow rate of hydraulic fluid supplied to each of the first and second hydraulic clutches and a controlling means for controlling the electric motor and the flow rate variable mechanism. The driving force distributing device can variably control a flow rate of hydraulic fluid supplied to first and second hydraulic clutches based on changing a ratio of flow rate of hydraulic fluid supplied to the first and second hydraulic clutches in the flow rate variable mechanism and a control of changing rotational speed of the pump using the motor.

A variable displacement oil pump includes: a variable displacement mechanism that is able to change a discharge amount per rotation of an input shaft. The variable displacement mechanism includes a pump housing, an oil pressure chamber provided in the pump housing, and a capacity adjustment member displaced by oil pressure from the oil pressure chamber. The capacity adjustment member is configured to be operated when receiving control oil pressure that is supplied from a control valve to the oil pressure chamber. The pump housing has an oil release hole that is opened to face the oil pressure chamber and that penetrates a wall section of the pump housing to partially release oil.

An adjustable vane pump, in particular an oil pressure pump, with a suction side and a pressure side, with a housing and with a rotor, which is supported in the housing so as to be rotatable about a rotor axis and carries at least one vane supported movably in a radial direction, wherein the housing comprises a housing floor and a housing cover transversely to the rotor axis, and wherein an adjustment cage that is arranged between the housing floor and the housing cover, encloses the rotor and the vane and is adjustable transversely to the rotor axis is provided in the housing, wherein the housing and the adjustment cage delimit a pressure chamber fluidically connected to the pressure side, wherein a restoring element is provided, which pushes the adjustment cage into a base end position, and wherein the adjustment cage is deflected from the base end position when a limit operating variable is exceeded in the pressure chamber.

Variable capacity vane pump 1 supplying working fluid to power steering device of vehicle has pump housing 2 formed from bottomed cylindrical-shaped front housing 5 and rear housing 6 closing the front housing, pump element 3 accommodated in pump housing, communicating with inlet passage 23 and with outlet passage 30 and sucking and discharging working fluid, and flow amount control valve 33 controlling an amount of working fluid discharged by pump element. Pressure-sensitive valve 50, which changes a flow passage cross-sectional area of the outlet passage so that the discharge amount of the pump element is increased with increase in load pressure of power steering device, is set at some midpoint of the outlet passage and at bottom wall portion 5b of front housing. It is therefore possible to suppress increase in size of device while reducing energy loss when variable capacity vane pump is mounted in power steering device.