Variable displacement-type oil pump

Patent metadata

Field	Value
Publication number	US-10947972-B2
Application number	US-201615758901-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Sep 18, 2015
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

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.

First claim

The invention claimed is:

1. A variable displacement oil pump comprising:
a pump configuration unit that is driven and rotates by an engine and discharges oil sucked from an inlet portion to an outlet portion by volumes of a plurality of pump chambers being varied;
a movable member that is able to change a volume variation of each of the plurality of pump chambers by movement of the movable member;
a forcing mechanism, having a set load provided, that forces the movable member in a direction in which the volume variation of each of the plurality of pump chambers is increased;
one or more control oil chambers that changes the volume variation of each of the plurality of pump chambers, the control oil chambers including at least a decrease side control oil chamber that exerts a force on the movable member in a direction in which the volume variation of each of the plurality of pump chambers is decreased by being supplied with the oil discharged from the outlet portion;
a drain mechanism that discharges the oil from specified one control oil chamber among the control oil chambers;
an electrical control mechanism into which a downstream side oil discharged from the outlet portion and passing through an oil filter provided on a discharge passage connected to the outlet portion is introduced and which is able to regulate a discharge pressure, which is a hydraulic pressure of the oil discharged from the outlet portion, to a plurality of setting pressures by controlling supply and discharge of the oil discharged from the outlet portion to and from the specified one control oil chamber on the basis of an electric signal and adjusting an internal pressure of the specified one control oil chamber, the electrical control mechanism configured to, when not being energized, not introduce oil to the specified one control oil chamber; and
a control valve into which the downstream side oil discharged from the outlet portion and passing through the oil filter and without passing through the electrical control mechanism is introduced as a control pressure, the control valve configured to, when a hydraulic pressure of the introduced oil exceeds a predetermined setting working pressure, adjust the internal pressure of the specified one control oil chamber by supplying the oil discharged from the outlet portion into the specified one control oil chamber or discharging the oil from the specified one control oil chamber.

2. The variable displacement oil pump as claimed in claim 1 , wherein:
the oil supplied into the decrease side control oil chamber is the downstream side oil discharged from the outlet portion.

3. The variable displacement oil pump as claimed in claim 2 , wherein:
the specified one control oil chamber is the decrease side control oil chamber.

4. The variable displacement oil pump as claimed in claim 3 , wherein:
the drain mechanism is provided at the electrical control mechanism.

5. The variable displacement oil pump as claimed in claim 3 , wherein:
the drain mechanism is provided at a pump housing that accommodates therein the pump configuration unit.

6. The variable displacement oil pump as claimed in claim 3 , wherein:
the drain mechanism is provided at the control valve.

7. The variable displacement oil pump as claimed in claim 2 , wherein:
the specified one control oil chamber is an increase side control oil chamber that exerts a force on the movable member in a direction in which the volume variation of each of the plurality of pump chambers is increased by being supplied with the oil discharged from the outlet portion.

8. The variable displacement oil pump as claimed in claim 7 , wherein:
the increase side control oil chamber is supplied with the downstream side oil discharged from the outlet portion through the decrease side control oil chamber, and
the electrical control mechanism controls discharge of the oil from the increase side control oil chamber.

9. The variable displacement oil pump as claimed in claim 1 , wherein:
the oil supplied into the decrease side control oil chamber is an upstream side oil of the outlet portion.

10. The variable displacement oil pump as claimed in claim 1 , wherein:
when the control valve works, the electrical control mechanism is set to an OFF state.

11. The variable displacement oil pump as claimed in claim 10 , wherein:
the setting working pressure of the control valve is set within a pressure range that is equal to or greater than a maximum requiring pressure which the engine requires.

12. A variable displacement oil pump comprising:
a rotor that is driven and rotates by an internal combustion engine;
a plurality of vanes that are accommodated at an outer periphery of the rotor so as to be able to extend and retract;
a cam ring that defines a plurality of pump chambers by accommodating the rotor and the vanes at an inner circumferential side of the cam ring, and increases and decreases a volume variation of each of the plurality of pump chambers by an eccentric movement of the cam ring with respect to the rotor;
an inlet portion that is formed in an inlet area where an inside volume of the pump chamber is increased;
an outlet portion that is formed in an outlet area where the inside volume of the pump chamber is decreased;
a forcing mechanism, having a pre-load provided, that forces the cam ring in a direction in which the volume variation of each of the plurality of pump chambers is increased;
one or more control oil chambers that changes the volume variation of each of the plurality of pump chambers, the control oil chambers including at least a decrease side control oil chamber that exerts a force on the cam ring in a direction in which the volume variation of each of the plurality of pump chambers is decreased by being supplied with the oil discharged from the outlet portion;
a drain mechanism that discharges the oil from specified one control oil chamber among the control oil chambers;
an electrical control mechanism into which a downstream side oil discharged from the outlet portion and passing through an oil filter provided on a discharge passage connected to the outlet portion is introduced and which is able to regulate a discharge pressure, which is a hydraulic pressure of the oil discharged from the outlet portion, to a plurality of setting pressures by controlling supply and discharge of the oil discharged from the outlet portion to and from the specified one control oil chamber on the basis of an electric signal and adjusting an internal pressure of the specified one control oil chamber, the electrical control mechanism configured to, when not being energized, not introduce oil to the specified one control oil chamber; and
a control valve into which the downstream side oil discharged from the outlet portion and passing through the oil filter and without passing through the electrical control mechanism is introduced as a control pressure, the control valve configured to, when a hydraulic pressure of the introduced oil exceeds a predetermined setting working pressure, adjust the internal pressure of the specified one control oil chamber by supplying the oil discharged from the outlet portion into the specified one control oil chamber or discharging the oil from the specified one control oil chamber.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Naganuma Atsushi
• Ohnishi Hideaki

Classifications

• F04C2/3441 Primary

  the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation · CPC title

• F04C14/226

  by pivoting the cam around an eccentric axis · CPC title

• F04C14/24

  characterised by using valves controlling pressure or flow rate, e.g. discharge valves {or unloading valves}(F04C14/10 takes precedence) · CPC title

• F04C14/22 Primary

  by changing the eccentricity between cooperating members · CPC title

• F04C2/344

  with vanes reciprocating with respect to the inner member · CPC title