Abstract: A variable displacement pump including a control mechanism shiftable between first and second states, when the control mechanism is in the first state, the spool is in an initial position in which fluid communication between an introduction port and the remaining ports is restrained, fluid communication between a first control port and a drain port is allowed, and fluid communication between a second control port and the drain port is restrained, and when the control mechanism is shifted to the second state in accordance with increase in fluid pressure discharged, the spool is in an operating position in which the fluid communication between the introduction port and the first control port is allowed, the fluid communication between the first control port and the drain port is restrained, and the fluid communication between the second control port and the drain port is allowed.

Abstract: A variable displacement oil pump for an automotive engine. The oil pump includes a cam ring accommodating thereinside a pump element having a rotor. The cam ring is swingingly movably accommodated in a housing and biased in a direction to increase an eccentricity amount of the cam ring relative to the axis of the rotor by a biasing member. First and second pressure chambers are defined inside the housing by the outer peripheral section of the cam ring. The first pressure chamber is supplied with a discharge pressure to be applied to the cam ring to oppose to a biasing force of the biasing member. The second pressure chamber is supplied with the discharge pressure to be applied to the cam ring to assist the biasing force of the biasing member. Additionally, a control device is provided for controlling supply of the discharge pressure to the second pressure chamber.

Abstract: A variable displacement pump includes a pump structural member configured to change volumes of a plurality of working chambers by rotation of a rotor, so as to introduce oil through an inlet port into the working chambers and to discharge the oil through a discharge port, and further configured to oscillate a cam ring by a discharge pressure introduced into a control oil chamber. A first coil spring is provided to force the cam ring in a direction for increasing of a rate of change of the working-chamber volume. A second coil spring is provided to force the cam ring in a direction for decreasing of the rate of change of the working-chamber volume. The first and second coil springs are laid out on both sides of an arm portion of the cam ring in a manner so as to be opposed to each other.

Abstract: Variable displacement oil pump includes a: rotor; vanes; cam ring; housing; biasing member biasing the cam ring in a direction enlarging an eccentricity between centers of the rotor and inner circumferential surface of the cam ring; a contact surface to contact with a cam ring outer circumferential surface via a biasing force applied to the cam ring by the biasing member; a control chamber separately formed by the contact surface and a swing fulcrum of the cam ring on a cam ring outer circumference when the contact surface contacts the cam ring outer circumferential surface, and causing the cam ring to swing against the biasing force of the biasing member by a pressure from a discharge portion to the control chamber; and a choking portion formed on the outer circumferential surface of the cam ring to maintain a pressure of the control chamber even when the cam ring swings.

Abstract: A variable displacement pump includes: a first control oil chamber which moves a cam ring toward a direction against a biasing force of a biasing member when a discharge pressure is introduced thereinto; a second control oil chamber which acts a hydraulic pressure upon the cam ring by cooperating with the biasing force of the biasing member when hydraulic oil is introduced thereinto; a switching mechanism which switches between one state in which hydraulic oil whose pressure is decreased than a discharge pressure is introduced to the second control oil chamber from the discharge section and another state in which hydraulic oil is discharged from the second control oil chamber; and a control mechanism operated before an eccentricity of the cam ring becomes a minimum and which discharges a greater amount of hydraulic oil within the second control oil chamber as the discharge pressure becomes larger.

Abstract: A variable displacement pump includes: a first urging member arranged to urge the cam ring in a direction to increase the eccentric amount; a second urging member arranged to urge the cam ring in a direction to decrease the eccentric amount; a control hydraulic chamber arranged to receive a discharge pressure, and thereby to move the cam ring against the urging force of the first urging member; and a hydraulic pressure introduction section configured to introduce the discharge pressure to the control hydraulic chamber when the discharge pressure becomes greater than a predetermined pressure which is in a range where the cam ring is movable against a resultant force of the urging forces of the first and second urging members, and where the cam ring is not movable only against the urging force of the first urging member.

Abstract: An oil pump includes: a valve receiving hole including; a first port connected with the suction port, a second port connected with the switching port, a third port connected with the discharge port, and a discharge pressure introduction port arranged to receive the discharge pressure, a valve element arranged to switch a first state in which the second port and the third port are connected, and a second state in which the first port and the second port are connected; and an urging member arranged to urge the valve element toward the first end side, the pressure receiving area of the valve element and the urging force of the urging member being set so that the oil pump is switched from the first state to the second state when the pressure within the hydraulic fluid chambers to which the switching port is opened is a negative pressure.

Abstract: In a variable displacement vane pump employing a cam ring, a pump rotor, and a plurality of vanes, each slidably fitted into the rotor, a biasing member is provided to force the cam ring in a direction that a geometric center of an inner peripheral surface of the cam ring and a rotation center of the rotor are spaced apart from each other. A force, by which the cam ring can be oscillated against the biasing member in accordance with a buildup of a pressure in a pump discharge portion, acts on the inner peripheral surface of the cam ring.

Abstract: An oil pump includes a shaft bearing bore, a drive shaft supported by the shaft bearing bore, an annular space between an inner peripheral surface of the shaft bearing bore and an outer peripheral surface of the drive shaft, a communication passage portion formed on the side of a pumping chamber inside the shaft bearing bore, and a communication groove formed opposite to the communication passage portion inside the shaft bearing bore. The communication passage portion is communicated between a discharge port and the annular space, and the communication groove is communicated with the annular space. Oil is stored in the annular space from the discharge port via the communication passage portion, and the oil flows into sliding clearance spaces of first and second journal portions via the annular space and the communication passage portion and the communication groove.

Abstract: A variable displacement pump arranged to supply a hydraulic fluid to an oil jet arranged to inject the hydraulic fluid to a piston of an internal combustion engine, the variable displacement pump includes: a pump constituting section arranged to be driven and rotated by the internal combustion engine, and thereby to discharge the hydraulic fluid; a movable member arranged to decrease the flow rate discharged from the discharge portion by moving in one direction; a control section configured to move the movable member in the one direction by a predetermined amount when the discharge pressure becomes a first discharge pressure, and to further move the movable member in the one direction when the discharge pressure becomes a second discharge pressure larger than the first discharge pressure, the first discharge pressure being set smaller than the predetermined pressure at which the oil jet starts to inject the hydraulic fluid.

Abstract: A vane pump in which oil is drawn from at least one side, in an axial direction, of a cam ring and is discharged from at least one side, in the axial direction, of the cam ring, has a portion defined by a groove formed on an inner circumference surface of the cam ring. The groove extends along a circumferential direction of the inner circumference surface of the cam ring and is arranged in a position including a middle of an axial direction width on the inner circumference surface. The groove is arranged in an oil suction section or an oil discharge section of the cam ring.

Abstract: A variable displacement pump includes a pump structural member configured to change volumes of a plurality of working chambers by rotation of a rotor, so as to introduce oil through an inlet port into the working chambers and to discharge the oil through a discharge port, and further configured to oscillate a cam ring by a discharge pressure introduced into a control oil chamber. A first coil spring is provided to force the cam ring in a direction for increasing of a rate of change of the working-chamber volume. A second coil spring is provided to force the cam ring in a direction for decreasing of the rate of change of the working-chamber volume. The first and second coil springs are laid out on both sides of an arm portion of the cam ring in a manner so as to be opposed to each other.

Abstract: In a hydraulic pressure circuit including an introduction section through which oil is introduced, a main passage section installed at a downstream side of the introduction section to be communicated with a supply section through which oil is supplied to each of slide sections of an internal combustion engine, a branch passage branched from the main passage section to supply oil to a hydraulic pressure actuator, and a control valve having a valve body which is moved in accordance with a pressure of an upstream side thereof, and a variable capacitance pump configured to drain oil to the introduction section, the variable capacitance pump is configured to vary a drained flow quantity in accordance with the drained pressure of oil and a pressure under which the oil drained flow quantity is started to be varied is higher than a pressure under which the valve body is started to move.

Abstract: A variable displacement pump including a chamber volume varying mechanism including a moveable member, a first biasing member always biasing the moveable member in such a direction as to increase volumes of the working fluid chambers, and a second biasing member that is disposed with a set load and applies a biasing force to the moveable member in such a direction as to increase the volumes of the working fluid chambers when the moveable member is displaced against a biasing force of the first biasing member by a predetermined amount or more. The biasing force of the first biasing member is set such that before the moveable member is displaced against the biasing force of the first biasing member, the valve timing control device is shifted to a release state in which an open-and-closure timing of an engine valve is variably controlled.

Abstract: A variable displacement oil pump includes a rotor; a plurality of vanes; a cam ring; a housing; a biasing member configured to biases the cam ring in a direction that enlarges an eccentricity between a rotation center of the rotor and a center of inner circumferential surface of the cam ring; a contact surface configured to become in contact with an outer circumferential surface of the cam ring by means of a biasing force applied to the cam ring by the biasing member; a control chamber separately formed by the contact surface and a swing fulcrum of the cam ring on an outer circumference of the cam ring when the contact surface is in contact with the outer circumferential surface of the cam ring, and configured to cause the cam ring to swing against the biasing force of the biasing member by a pressure introduced from a discharge portion to the control chamber; and a choking portion formed on the outer circumferential surface of the cam ring so as to maintain a pressure of the control chamber even when the cam

Abstract: A variable displacement oil pump for an automotive engine. The oil pump includes a cam ring accommodating thereinside a pump element having a rotor. The cam ring is swingingly movably accommodated in a housing and biased in a direction to increase an eccentricity amount of the cam ring relative to the axis of the rotor by a biasing member. First and second pressure chambers are defined inside the housing by the outer peripheral section of the cam ring. The first pressure chamber is supplied with a discharge pressure to be applied to the cam ring to oppose to a biasing force of the biasing member. The second pressure chamber is supplied with the discharge pressure to be applied to the cam ring to assist the biasing force of the biasing member. Additionally, a control device is provided for controlling supply of the discharge pressure to the second pressure chamber.

Abstract: An oil pump includes pump chambers each having a volume varied by engine drive and for pressurizing oil inhaled through an inlet port and discharge it through an outlet port, and a branch passage connected between upstream and downstream sides of the outlet port at branch and confluent points, wherein the branch passage in the vicinity of the confluent point is shifted in pulse-pressure phase with respect to the outlet port.

Abstract: In a variable displacement vane pump employing a cam ring, a pump rotor, and a plurality of vanes, each slidably fitted into the rotor, a biasing member is provided to force the cam ring in a direction that a geometric center of an inner peripheral surface of the cam ring and a rotation center of the rotor are spaced apart from each other. A force, by which the cam ring can be oscillated against the biasing member in accordance with a buildup of a pressure in a pump discharge portion, acts on the inner peripheral surface of the cam ring.

Abstract: A variable displacement pump including a chamber volume varying mechanism including a moveable member, a first biasing member always biasing the moveable member in such a direction as to increase volumes of the working fluid chambers, and a second biasing member that is disposed with a set load and applies a biasing force to the moveable member in such a direction as to increase the volumes of the working fluid chambers when the moveable member is displaced against a biasing force of the first biasing member by a predetermined amount or more. The biasing force of the first biasing member is set such that before the moveable member is displaced against the biasing force of the first biasing member, the valve timing control device is shifted to a release state in which an open-and-closure timing of an engine valve is variably controlled.

Abstract: An oil pump to be insatalled to an engine of an automotive vehicle. The oil pump includes a section defining a suction port and a section defining a discharge port. A main unit of the oil pump has a section defining a plurality of pump chambers. Volume of each pump chamber continuously changes to increase and decrease under driving of the engine so as to pressurize oil sucked through the suction port and discharge the oil through the discharge port. A section defining an oil chamber to which the oil flows is provided such that the oil chamber has a vertically upper side which is communicated with the discharge port through a communicating hole.