A variable displacement oil pump for an internal combustion engine includes a pump element to vary inside volumes of pumping chambers to suck and discharge an oil, a varying mechanism to vary a pumping volume variation quantity of the pumping chambers, with movement of a movable member such as a cam ring, an urging mechanism to urge the movable member in a direction to increase the pumping volume variation quantity, first and second control oil chambers to urge the movable member to vary the pumping volume variation quantity, and a control mechanism, such as a pilot valve, to control the supply/drainage of the oil to or from the second control oil chamber. An operation oil pressure of the movable member is set higher than an operation oil pressure of the control mechanism in a higher pressure region.

A multiple vane kinetic system produces variation in an enclosed volume between pairs of radial vane sets independent of each other and coaxial with a central axis within a annular casing that encapsulates the vane sets. The system operates in a sequence where the vane sets function as rotating links of the mechanism for a particular period, which is preceded and succeeded by another period where either vane sets successively alternate between being a fixed link and a rotating link of the mechanism and during the former period the volumes between vanes remain constant as long as the vane sets have equal angular velocities, otherwise varies at rates proportional to differing angular velocities. The two time periods are controlled by timing devices actuating vane sets to be coupled and decoupled with a power shaft and the variation in length of two time periods makes roto-dynamic variable displacement machine.

A multiple vane kinetic system produces variation in an enclosed volume between pairs of radial vane sets independent of each other and coaxial with a central axis within a annular casing that encapsulates the vane sets. The system operates in a sequence where the vane sets function as rotating links of the mechanism for a particular period, which is preceded and succeeded by another period where either vane sets successively alternate between being a fixed link and a rotating link of the mechanism and during the former period the volumes between vanes remain constant as long as the vane sets have equal angular velocities, otherwise varies at rates proportional to differing angular velocities. The two time periods are controlled by timing devices actuating vane sets to be coupled and decoupled with a power shaft and the variation in length of two time periods makes roto-dynamic variable displacement machine.

An oil pump structure including: an oil pump having a first hydraulic control chamber and a second hydraulic control chamber; a hydraulic control valve having a valve operating oil passage, a first inflow passage, a second inflow passage, a first outflow passage, a second outflow passage and a drain flow passage; and an oil circuit, wherein the hydraulic control valve is connected to a branching flow passage of the oil circuit; a spool valve body of the hydraulic control valve has a front valve section, a rear valve section and an intermediate valve section, which are formed perpendicularly to the axial direction of a connecting shaft; an axial-direction dimension of the intermediate valve section is larger than an axial-direction dimension of the second outflow passage; the second outflow passage and the drain flow passage are both accommodated temporarily between the intermediate valve section and the front valve section due to movement of the spool valve body; and in the hydraulic control valve, a control hydraulic pressure is applied at all times to the first hydraulic control chamber, and the control hydraulic pressure is increased and decreased in the second hydraulic control chamber.

A vane pump includes a rotor including a first annular groove and a second annular groove. The rotor further includes a cylindrical portion projecting axially from a radial inner side of the first annular groove and fitting over a drive shaft, and a slide contact portion formed on a radial inner side of the second annular groove. The cylindrical portion is slidably received in a bearing hole formed in a first side wall of a housing, whereas the slide contact portion abuts slidably on an inside wall surface of a second side wall of the housing. There is further formed, in the first annular groove, a recessed portion making a pressure receiving area of one of the first and second annular grooves greater than a pressure receiving area of the other of the first and second annular grooves.

A variable displacement vane pump has a pressure controlled valve moveable between first and at least second valve positions based on an output pressure of the pressurized lubricant delivered through the outlet. The pressure controlled valve provides an integrated fail safe function to the pump when an electrical valve fails. The pressure controlled valve is inactive in the first position for an output pressure below a threshold level, allowing an electrical valve (pulse width modulation (PWM) valve) to selectively control pressure in the control chamber under normal operation of the pump. In fail safe regulation mode, the electrical valve function is disabled and the pressure controlled valve is active in its second position, controlling pressure in the control chamber. Channels and vents in the pump can be opened and closed based on selective movement of the valve when the outlet pressure is at or above a threshold level.

A variable capacity vane pump for an automobile includes a pump control ring positioned within the housing to move about a pivot. A rotor is positioned within a cavity of the control ring such that a position of the control ring determines an offset between a center of the cavity and an axis of rotation of the rotor. A first control chamber is provided between the pump housing and a first outer surface of the control ring. The first outer surface is positioned on an opposite side of the control ring as the working fluid chambers within the cavity. A second control chamber is provided between the pump housing and a second outer surface of the control ring. A return spring biases the control ring toward a position of maximum volumetric capacity against the forces created by the pressurized fluid within the first and second control chambers.

A variable capacity vane pump for an automobile includes a pump control ring positioned within the housing to move about a pivot. A rotor is positioned within a cavity of the control ring such that a position of the control ring determines an offset between a center of the cavity and an axis of rotation of the rotor. A first control chamber is provided between the pump housing and a first outer surface of the control ring. The first outer surface is positioned on an opposite side of the control ring as the working fluid chambers within the cavity. A second control chamber is provided between the pump housing and a second outer surface of the control ring. A return spring biases the control ring toward a position of maximum volumetric capacity against the forces created by the pressurized fluid within the first and second control chambers.