US 2015/0020759 A1Published application

Variable displacement pump

AssigneeHitachi Automotive Systems, Ltd.

InventorsYasushi WATANABE, Hideaki OHNISHI

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Abstract

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.

Claims16

Dependent claims

A variable displacement pump for an internal combustion engine, to supply an oil to a hydraulic variable valve actuation device, an oil jet and a crankshaft bearing, comprising:

a rotor adapted to be driven by the internal combustion engine;
a plurality of vanes slidably received in an outer circumference of the rotor;
a cam ring which includes an inside circumferential surface enclosing the rotor and the vanes, having a center line eccentric from a rotation axis of the rotor, and defining a plurality of operating oil chambers, and which is arranged to move to vary an eccentricity and thereby to vary a pumping volume;
is an intake portion opening into the operating oil chambers in a volume increasing region in which volumes of the operating oil chambers are increased with rotation of the rotor;
a discharge portion opening into the operating oil chambers in a volume decreasing region in which the volumes of the operating oil chambers are decreased with rotation of the rotor;
an urging mechanism including first and second spring members provided with respective spring loads, and arranged to apply an urging force to the cam ring in an eccentric direction with a spring force produced by the first and second spring members, and to increase the urging force of the first and second spring members stepwise when the cam ring is rotated in a concentric direction from a maximum eccentric position and an eccentricity of the cam ring becomes smaller than or equal to a predetermined value;
a first control chamber arranged to receive an oil discharged from the discharge portion and to apply a force to the cam ring in a direction decreasing the eccentricity;
a second control chamber arranged to receive the oil discharged from the discharge portion and to apply a force smaller than the force produced by the first control chamber, to the cam ring in a direction increasing the eccentricity;
a thermosensitive mechanism to connect the second control chamber with the discharge portion in a higher oil temperature state and to connect the second control chamber with a low pressure portion in a low oil temperature state;
and
a control valve to be operated by a discharge pressure of the discharge portion and to decrease a pressure in the second control chamber when the discharge pressure of the discharge portion becomes higher than or equal to a so predetermined pressure.

8 more elements

A variable displacement pump for an internal combustion engine, comprising:

a pump forming member arranged to vary volumes of a plurality of operating oil chambers by being driven by the internal combustion engine, to suck an oil from an intake portion and to discharge the oil from a discharge portion;
a varying mechanism including a movable member to move to vary volume variation of the operating oil chambers opening to the discharge portion;
an urging mechanism including first and second spring members arranged to apply, to the movable member, an urging force increasing the volume variation of the operating oil chambers opening in the discharge portion with a spring force produced by the first and second spring members, and to increase the urging force of the first and second spring members stepwise when the volume variation is decreased to a value smaller than or equal to a predetermined value from a maximum volume variation state of the movable member;
a first control chamber arranged to receive an oil discharged from the discharge portion and to apply a force to the movable member in a direction decreasing the volume variation of the operating oil chambers opening in the discharge portion;
a second control chamber arranged to receive the oil discharged from the discharge portion and to apply a force smaller than the force produced by the first control chamber, to the movable member in a direction increasing the volume variation of the operating oil chambers opening in the discharge portion;
a thermosensitive mechanism to control a communication area between the second control chamber and the discharge portion and a communication area between the second control chamber and a low pressure portion, in dependence on an oil temperature condition;
and
a control valve to be operated by a discharge pressure of the discharge portion and to decrease a pressure in the second control chamber when the discharge pressure of the discharge portion becomes higher than or equal to a predetermined pressure.

5 more elements

A variable displacement pump for an internal combustion engine, comprising:

a rotor adapted to be driven by the internal combustion engine;
a plurality of vanes slidably received in an outer circumference of the rotor;
a cam ring which surrounds the rotor and the vanes, which has a center line eccentric from a rotation axis of the rotor, which defines a plurality of operating oil chambers, and which is arranged to move to vary an eccentricity and thereby to vary a pumping volume;
an intake portion to open into the operating oil chambers in a volume increasing region in which volumes of the operating oil chambers are increased with rotation of the rotor;
a discharge portion to open into the operating oil chambers in a volume decreasing region in which the volumes of the operating oil chambers are decreased with rotation of the rotor;
an urging mechanism including first and second spring members arranged to apply an urging force to the cam ring in an eccentric direction with a spring force produced by the first and second springs, and to increase the urging force stepwise when the cam ring is rotated in a concentric direction from a maximum eccentric position and an eccentricity of the cam ring becomes smaller than or equal to a predetermined value;
a first control chamber arranged to receive an oil discharged from the discharge portion and to apply a force to the cam ring in a direction decreasing the eccentricity;
a second control chamber arranged to receive the oil discharged from the discharge portion and to apply a force varying the eccentricity, to the cam ring;
a thermosensitive mechanism to change over connection of the second control chamber between the discharge portion and a low pressure portion, in dependence on an oil temperature and to decrease the force applied to the cam ring in a direction decreasing the eccentricity when the oil temperature is high;
and
a control valve to be operated by a discharge pressure of the discharge portion and to increase the force applied to the cam ring in the direction decreasing the eccentricity by adjusting a pressure in the second control chamber when the discharge pressure of the discharge portion becomes higher than or equal to a predetermined pressure.

8 more elements

A variable displacement pump for an internal combustion engine, comprising:

a pump forming member arranged to vary volumes of a plurality of operating oil chambers by being driven by the internal combustion engine, to suck an oil from an intake portion and to discharge the oil from a discharge portion;
a varying mechanism including a movable member to move to vary volume variation of the operating oil chambers opening to the discharge portion;
an urging mechanism including first and second spring members disposed in respective loaded states, and arranged to produce an urging force urging the movable member in a direction increasing the volume variation of the operating oil chambers opening in the discharge portion, and to increase the urging force stepwise when the volume variation is decreased to a value smaller than or equal to a predetermined value;
a first control chamber arranged to receive an oil discharged from the discharge portion and to apply a force to the movable member in a direction decreasing the volume variation of the operating oil chambers opening in the discharge portion;
a second control chamber arranged to receive the oil discharged from the discharge portion and to apply, to the movable member, a force varying the volume variation of the operating oil chambers opening in the discharge portion;
a thermosensitive mechanism to control a communication area of a communication passage between the second control chamber and the discharge portion and a communication area of a communication passage between the second control chamber and a low pressure portion, in dependence on an oil temperature, and to decrease a force applied to the movable member in a direction decreasing the eccentricity in a high oil temperature state;
and
a control valve to be operated by a discharge pressure of the discharge portion and to adjust a pressure in the second control chamber and thereby to increase a force applied to the movable member in a direction decreasing the eccentricity when the discharge pressure of the discharge portion becomes higher than or equal to a predetermined pressure.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/319,597Filed 30 Jun 2014
Priority: JP 2013-14809817 Jul 2013
Published: 22 Jan 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

F01L 1/3442
Changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear: using hydraulic chambers with variable volume to…
F04C 2/3442
The inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation: the surfaces of…
F04C 14/226
Using a movable cam: by pivoting the cam around an eccentric axis
F01L 2001/34423
Using hydraulic chambers with variable volume to transmit the rotating force: details relating to the hydraulic feeding circuit

Family

US 9,518,484 B2Related patent
US 2015/0020759 A1This patent

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