Hitachi Automotive Systems, Ltd.

Hitachi, Ltd.

Hitachi Astemo Ltd.

Unisia Jecs Corporation

Hideaki Ohnishi

Yasushi Watanabe

Koji Saga

Atsushi Naganuma

Shoji Morita

Yoshinori Ichinosawa

Hiroyuki Kato

Daisuke Kato

Iwao Kondo

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

A variable displacement pump device includes a pump, a mover, a biasing member, first and second control chambers, and a controller. The first and second control chambers are provided between an inner periphery of a containing chamber of a housing and an outer periphery of the mover. Hydraulic oil is introduced from a discharge port into the first control chamber. The pump is configured to permit oil to be introduced from the discharge port into the second control chamber via a supply/discharge passage or to be discharged from inside the second control chamber. The second control chamber is located adjacent to any of the pump chambers in a discharge region or the discharge port via the mover. The controller is configured to switch states in which the second control chamber is opened and closed to the supply/discharge passage.

Variable displacement pump and control method therefor

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

Variable displacement pump has first control hydraulic chambergiving force to cam ringin direction that decreases volume variation of each pump chamberby internal pressure, second control hydraulic chambergiving force to cam ring in direction that increases volume variation of each pump chamber by internal pressure, first seal surfaceformed on both end surfaces of cam ring, which are in sliding-contact with both opposing inside surfaces of pump bodyand cover member, and sealing gap between each pump chamber and first control hydraulic chamber, and second seal surfacesealing gap between each pump chamber and second control hydraulic chamber at outlet section side. Radial direction width Wof second seal surface is greater than that Wof first seal surface. Increase in weight of the pump can be suppressed while suppressing increase in pump control pressure against intention of control.

Variable displacement pump

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 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 pump includes a variable mechanism configured to change a volume-variation rate of each pump chamber by movement of a movable member; a biasing mechanism provided to bias the movable member in a direction that increases the volume-variation rate; at least one reduction-side control oil chamber to which oil is supplied from a discharge portion such that the reduction-side control oil chamber applies force to the movable member in a direction that reduces the volume-variation rate; at least one increase-side control oil chamber to which oil is supplied from the discharge portion such that the increase-side control oil chamber applies force to the movable member in the direction that increases the volume-variation rate; and a control mechanism configured to control a oil quantity which is supplied to each control oil chamber. The total number of the control oil chambers is three or more.

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.

Vane 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.

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.

A variable displacement pump includes an urging mechanism to urge a cam ring in an eccentric direction and to increase the urging force when an eccentricity is decreased, a first control chamber to apply a force to the cam ring in a direction decreasing the eccentricity, and a second control chamber to apply a force, to the cam ring, in a direction increasing the eccentricity. The variable displacement pump further includes a thermosensitive mechanism to control the supply and drain of a discharge pressure supplied into the second control chamber, and a control valve to be operated by the discharge pressure and to decrease the pressure in the second control chamber when the discharge pressure increases.

A variable displacement oil pump includes: a switching mechanism arranged to switch a state in which the hydraulic fluid is introduced to the second control hydraulic chamber through a connection passage, and a state in which the hydraulic fluid is discharged from the second control hydraulic chamber through the connection passage; and a control mechanism arranged to be actuated before the eccentric amount of the cam ring becomes minimum, and arranged to vary an opening area of the connection passage as the discharge pressure is increased, and to vary an opening area of a discharge passage arranged to discharge the hydraulic fluid within the second control hydraulic chamber, in a direction opposite to a direction of a variation of the opening area of the introduction passage.

An oil pump includes a relief valve. The relief valve adjusts a pump discharge pressure depending on a differential pressure between the pump discharge pressure and a back pressure chamber pressure. An electromagnetic switching valve includes a movable member moved electromagnetically. The movable member brings a ball valve element selectively into a state pressed onto a valve seat portion, to selectively close and open an oil passage. The electromagnetic switching valve selectively supplies the pump discharge pressure to a back pressure chamber of the relief valve and drains the back pressure chamber of the relief valve by selectively opening and closing the oil passage. A pilot valve is disposed downstream of the electromagnetic switching valve, and operates upon receipt of the pump discharge pressure or the back pressure chamber pressure, and controls an oil pressure supplied to the back pressure chamber of the relief valve.

Growing community of inventors

Atsugi, Japan

Hideaki Ohnishi