Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Atsushi Naganuma

Yasushi Watanabe

Hideaki Ohnishi

Koji Saga

Daisuke Kato

In a variable displacement type oil pump, a swing member accommodates a pump forming member, and swings to vary a quantity of change of a volumetric capacity of each pump chamber. A biasing member biases the swing member in a direction to increase the quantity of change of the volumetric capacity of each pump chamber. A first control oil chamber applies a first torque to the swing member in a direction to reduce the quantity of change of the volumetric capacity of each pump chamber. A second control oil chamber applies a second torque to the swing member in a direction to increase the quantity of change of the volumetric capacity of each pump chamber, wherein the second torque is larger than the first torque. A switching mechanism switches between supply and drain of working oil with respect to the second control oil chamber.

Variable displacement oil pump including swing member

Provided is a variable capacity pump where ease of control can be improved. A variable capacity pump includes a control chamber and a control mechanism. The control chamber is disposed between a pump accommodating chamber and a movable member, and the volume of the control chamber is variable with the movement of the movable member. Working oil discharged from a discharge portion is introduced into the control chamber. The control mechanism includes a spool, a biasing member, and a solenoid. The spool is provided in a passage, and is configured to control introduction of working oil into the control chamber by moving in a cylindrical portion. The spool is biased to one side in an axial direction by a pressure of working oil introduced into the cylindrical portion from the discharge portion. The biasing member biases the spool to an opposite side in the axial direction. The solenoid is configured to generate an electromagnetic force for biasing the spool in the axial direction, and to change a magnitude of the electromagnetic force according to a value of an electric current supplied.

Variable capacity pump and working oil supply system for internal combustion engine

A variable displacement oil pump includes: a pump constituting section; a movable member; an urging mechanism; a control hydraulic chamber group; a drain mechanism arranged to discharge the oil from a specific one control hydraulic chamber of the control hydraulic chamber group; and a control valve which into which the oil of an upstream side that is discharged from the discharge portion, or the oil from the control hydraulic chamber is introduced as a control hydraulic pressure, which is arranged to supply the oil of the upstream side that is discharged from the discharge portion to the specific one control hydraulic chamber, or to discharge the oil from the specific one control hydraulic chamber by the drain mechanism to regulate the pressure of the specific one control hydraulic chamber.

Variable capacity oil pump

Variable displacement-type oil pump has pump configuration unit driven by engine and discharging oil sucked from inlet portion from outlet portion by volumes of a plurality of pump chambers being varied; cam ring changing volume variation of each pump chamber by moving; coil spring forcing cam ring in direction in which volume variation of each pump chamber is increased; control oil chamber forcing cam ring in direction in which volume variation of each pump chamber is decreased; drain port draining oil from control oil chamber; control valve into which a downstream side oil discharged from outlet portion is introduced, and which adjusts internal pressure of control oil chamber by supplying oil into control oil chamber when hydraulic pressure of the introduced oil exceeds a predetermined setting working pressure. With this configuration, it is possible to suppress increase in electric power consumption associated with an electrical control mechanism.

Variable displacement-type oil pump

Oil pump and oil pump-integrated balancer device each have a pump housing formed by housing bodyand cover member, pump shafthaving driven side helical gearat which thrust force occurs when transmitting rotation force and rotating a rotor by the rotation force provided from drive side helical gearthat is engaged with driven side helical gear, first and second thrust receiving portionsformed close to hole edges of bearing holesof the cover member and the housing body, and first and second thrust limiting portionsprovided at the driven side helical gear and the pump shaft, contacting the thrust receiving portions from axis direction and limiting thrust movement of the pump shaft. With this configuration, oil pump and oil pump-integrated balancer device which are capable of securing stable support of the pump shaft are provided.

Oil pump and balancer unit of oil pump integrated type

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.

Variable displacement pump

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 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.

Variable displacement oil pump

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.

Variable displacement oil pump for supplying oil to an internal combustion engine. Included is a cam ring having an inner peripheral section for accommodating the pump element thereinside, and an outer peripheral section having a swinging movement fulcrum. A control device for changeover controlling supply of a discharge pressure to first and second pressure chambers so the cam ring is swingingly movable to change an eccentricity amount of the cam ring relative to an axis of the rotor, wherein the first pressure receiving surface is set larger in pressure receiving area than the second pressure receiving surface, wherein a part of each of the first and second pressure chambers is disposed overlapping with the discharge region in a radial direction of the rotor, and wherein the first and second pressure chambers are disposed nearer to the swinging movement fulcrum than to the axis of the cam ring.

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.

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Atsugi, Japan

Atsushi Naganuma