Variable displacement pump
AssigneeHitachi Automotive Systems, Ltd.
InventorAtsushi NAGANUMA
Life of this patent
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Abstract
A variable displacement pump includes: a pump constituting section; a movable member; a first control hydraulic chamber; a second control hydraulic chamber; a control mechanism arranged to be actuated by receiving a control hydraulic pressure which is the discharge pressure on a downstream side of the discharge portion, through a single control passage formed within the engine, and to control a supply and a discharge of the discharge pressure with respect to the second control hydraulic chamber; and a switching mechanism arranged to switch a connection and a disconnection between the control passage and the control mechanism.
Claims20
A variable displacement pump comprising:
- a pump constituting section arranged to be driven and rotated by an engine, to vary volumes of a plurality of pump chambers, and thereby to discharge an oil sucked from a suction portion from a discharge portion;
- a movable member arranged to be moved to vary variation amounts of the volumes of the pump chambers;
- an urging mechanism provided with a set load, and arranged to urge the movable member in a direction in which the variation amounts of the volumes of the plurality of the pump chambers are increased;
- a first control hydraulic chamber arranged to receive a discharge pressure from the discharge portion, and thereby to act a force to the movable member in a direction in which the variation amounts of the volumes of the plurality of the pump chambers are decreased;
- a second control hydraulic chamber arranged to receive the discharge pressure from the discharge portion, and thereby to act a force to the movable member in a direction in which the variation amounts of the volumes of the plurality of the pump chambers are increased;
- a control mechanism arranged to be actuated by receiving a control hydraulic pressure which is the discharge pressure on a downstream side of the discharge portion, through a single control passage formed within the engine, and to control a supply and a discharge of the discharge pressure with respect to the second control hydraulic chamber;
- and
- a switching mechanism arranged to switch a connection and a disconnection between the control passage and the control mechanism.
A variable displacement pump comprising:
- a rotor driven and rotated by an internal combustion engine;
- a plurality of vanes provided on an outer circumference of the rotor to be projectable and retractable;
- a cam ring which separates a plurality of pump chambers within the cam ring, with the rotor and the vanes, and which is arranged to be moved to vary an eccentric amount with respect to a center of the rotor, and thereby to increase or decrease pump volumes;
- a suction portion which is opened to the pump chambers, and in which the pump volumes are increased by the rotation of the rotor;
- a discharge portion which is opened to the pump chambers, and in which the pump volumes are decreased by the rotation of the rotor;
- an urging mechanism provided with a set load, and arranged to urge the cam ring in a direction in which the eccentric amount is increased;
- a first control hydraulic chamber arranged to receive a discharge pressure from the discharge portion, and thereby to act a force in a direction in which the eccentric amount is decreased, to the cam ring;
- a second control hydraulic chamber arranged to receive the discharge pressure from the discharge portion, and thereby to act a force in a direction in which the eccentric amount is increased, to the cam ring in cooperation with the urging member;
- a control mechanism arranged to control supply and discharge of the discharge pressure to the second control hydraulic chamber by a control hydraulic pressure passed and supplied through one control passage;
- and
- a switching mechanism provided to the internal combustion engine, and arranged to switch a connection or disconnection between the control mechanism and the control passage.
Dependencies are inferred from the claim text.