JP2014125918A - Variable capacity pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable capacity pump that is simplified in mechanism, and can continuously change a capacity according to an amount of hydraulic oil calculated on the basis of an engine speed or an engine load, etc.SOLUTION: A variable capacity pump 100 includes: a housing 1; a drive shaft 2 rotatably supported to the housing 1; an inner rotor 3 coupled to the drive shaft 2; vanes 4 retractably stored in slits 11 radially formed in an inner rotor 3; an outer rotor 5 eccentrically disposed to the inner rotor 3, and forming a hydraulic oil chamber 15 with the inner rotor 3 and the vanes 4; a pressure chamber 16 provided on an outer circumferential surface of the outer rotor 5; a pressure regulation spring 26 for biasing the outer rotor 5 to one side; a motor 31 as a pressure regulation mechanism to change a biasing force of a pressure regulation spring 26; and a control unit 40 for controlling the drive of the motor 31.

Description

  The present invention relates to a technology of a variable displacement pump, and more particularly to a technology of a variable displacement pump that supplies hydraulic oil to each part of an engine.

  2. Description of the Related Art Conventionally, variable displacement pumps that supply hydraulic oil to various parts of an engine are known (for example, see Patent Document 1). The variable displacement pump is formed in a housing, a drive shaft rotatably supported by the housing and rotated by a crankshaft, an inner rotor coupled to the drive shaft, and a radial shape on the inner rotor. A plurality of vanes accommodated in the slit so as to be able to be put in and out; and an outer rotor which is arranged to be eccentric with respect to the inner rotor and forms a hydraulic oil chamber together with the inner rotor and the vanes.

Two pressure chambers are provided on the outer peripheral side of the outer rotor, and the eccentric amount of the outer rotor is increased or decreased by applying a discharge hydraulic pressure or atmospheric pressure to the pressure chamber, thereby increasing or decreasing the volume of the hydraulic oil chamber. It is something to be made.
The variable displacement pump is provided with a spring that is a biasing member that constantly biases the outer rotor in a direction that increases the amount of eccentricity of the outer rotor.

JP 2010-209718 A

  However, the conventional variable displacement oil pump requires an oil pressure adjusting mechanism such as an oil passage or a hydraulic actuator for applying the discharge hydraulic pressure or the atmospheric pressure to the two pressure chambers. Further, since the spring, which is the urging member, is urged with a constant force, the relationship between the discharge hydraulic pressure and the urging force is uniquely determined. Therefore, it is possible to suppress the amount of oil by changing the capacity when the engine speed is high, but it is difficult to continuously change the capacity when the engine speed is low. . For this reason, the amount of hydraulic oil required by each part of the engine varies depending on, for example, the engine speed, the engine load, and the like, so there is a region where hydraulic oil is excessively supplied.

  In view of the above problems, the present invention provides a variable displacement pump capable of simplifying the mechanism and continuously changing the capacity according to the amount of hydraulic oil calculated based on the engine speed, engine load, and the like. .

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to the first aspect of the present invention, the housing, the drive shaft rotatably supported by the housing, the inner rotor coupled to the drive shaft, and the slits radially formed on the inner rotor can be inserted and removed. An accommodated vane, an outer rotor that is arranged eccentrically with respect to the inner rotor, forms a hydraulic oil chamber together with the inner rotor and the vane, a pressure chamber provided on an outer peripheral surface of the outer rotor, An urging member that urges the outer rotor in an eccentric direction, a pressure adjusting mechanism that changes the urging force of the urging member, and a control device that controls driving of the pressure adjusting mechanism are provided.

  According to a second aspect of the present invention, the pressure adjusting mechanism is constituted by a motor, and the motor is connected to an end of the urging member, and the urging force is changed by expanding and contracting the urging member.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, since the volume of the hydraulic oil chamber can be increased or decreased by changing the urging force of the urging member by the pressure adjusting mechanism, the discharge hydraulic pressure or the atmospheric pressure is applied to the two pressure chambers. A hydraulic adjustment mechanism such as an oil passage or a hydraulic actuator is unnecessary, and the mechanism is simplified. Further, by changing the urging force of the urging member while controlling the drive of the pressure adjusting mechanism by the control device, the capacity of the variable displacement pump can be changed according to the required oil amount.

  In the second aspect, in addition to the effect of the first aspect, the urging force of the urging member can be continuously changed by controlling the driving of the motor by the control device, and according to the required amount of oil. The capacity of the variable displacement pump can be continuously changed.

1 is a plan sectional view showing a variable displacement pump according to a first embodiment of the present invention. The plane sectional view showing a variable displacement pump similarly. The graph which similarly shows the relationship between discharge hydraulic pressure and engine speed. The plane sectional view showing the variable capacity pump concerning a second embodiment of the present invention. The plane sectional view showing a variable displacement pump similarly.

  Next, embodiments of the invention will be described. FIG. 1 is a plan sectional view of the variable displacement pump, and it is defined that the front side of the page is the upper side and the back side is the lower side.

The variable displacement pump 100 according to the first embodiment of the present invention is a device that is provided in a cylinder block or the like of an engine (not shown) and supplies hydraulic oil to each part of the engine.
As shown in FIGS. 1 and 2, the variable displacement pump 100 includes a housing 1, a drive shaft 2, an inner rotor 3, a vane 4, an outer rotor 5, and a pressure chamber 16.

  The housing 1 is a container in which the drive shaft 2, the inner rotor 3, the vane 4, and the outer rotor 5 are stored. In the present embodiment, the housing 1 is configured in a substantially quadrangular shape in plan view, and has a substantially quadrangular space inside, and is connected to the cylinder block at four corners of the outer periphery in plan view. A screw hole 1a is provided. One of the side surfaces of the housing 1 is provided with a pressure adjusting hole 1b communicating with a pressure adjusting housing 21 described later.

  The drive shaft 2 is a shaft that rotates the inner rotor 3 by a rotational force transmitted from a power transmission shaft such as a crankshaft (not shown), and is rotatably supported by the housing 1. One end of the drive shaft 2 is connected to the power transmission shaft.

  The inner rotor 3 is coupled to the drive shaft 2 and rotates together with the drive shaft 2. The inner rotor 3 is provided on a concentric circle of the drive shaft 2, and a plurality of slits 11 are notched radially from the inner center side to the radially outer side. A back pressure chamber 12 having a substantially circular cross section for introducing hydraulic oil is provided at the inner base end of each slit 11.

The vane 4 is accommodated in the slit 11 so that it can be taken in and out. In the vane 4, each front end surface on the outer peripheral side abuts on the inner peripheral surface of the outer rotor 5, and each front end surface on the inner peripheral side abuts on the outer peripheral surface of the ring member 13.
The ring member 13 is a member that prevents the vane 4 from moving toward the inner peripheral side by abutting with the inner peripheral side tip portion of the vane 4, is formed in a cylindrical shape, and is provided inside the inner rotor 3. . The tip of the inner peripheral side of the vane 4 is in contact with the outer peripheral surface of the ring member 13.

  The outer rotor 5 is arranged so as to be eccentric with respect to the inner rotor 3. The inner peripheral surface of the outer rotor 5 is formed in a circular shape in plan view, and the outer front end surface of the vane 4 is in contact with the inner peripheral surface. By comprising in this way, the outer peripheral surface of the inner rotor 3, the inner surface of the adjacent vane 4, the inner peripheral surface of the outer rotor 5, and the both bottom surfaces of the housing 1 are liquid-tightly divided and surrounded by each. The space becomes the hydraulic oil chamber 15.

Further, the outer peripheral surface of the outer rotor 5, the inner peripheral surface of the housing 1, and both bottom surfaces of the housing 1 are partitioned, and each enclosed space serves as one pressure chamber 16.
The pressure chamber 16 is configured such that the discharge oil discharged to the discharge port 17 is always introduced through an introduction path (not shown). As a result, the discharge hydraulic pressure is evenly applied to the outer peripheral surface of the outer rotor 5.

  A pressure regulating housing 21 having a pressure regulating chamber 22 formed therein is provided on the side of the housing 1. A pressure regulating chamber 22 is formed in the pressure regulating housing 21 in parallel with the longitudinal direction. The pressure regulating chamber 22 is configured to communicate with a pressure regulating hole 1 b provided on the side surface of the housing 1. The pressure adjusting chamber 22 stores a pressure receiving piston 25 and a pressure adjusting spring 26 as an urging member. A pressure adjusting mechanism is provided at the end of the pressure adjusting chamber 22 opposite to the pressure adjusting hole 1b. ing.

Next, the pressure regulating mechanism according to the present embodiment will be described.
In the present embodiment, the pressure adjusting mechanism is configured by a motor 31.
The motor 31 has a shaft 31 a and is a device that expands and contracts the shaft 31 a in the longitudinal direction of the pressure regulating chamber 22 step by step. In the present embodiment, the motor 31 is a stepping motor, and by electrically connecting the motor 31 and the control device 40, the expansion / contraction amount of the shaft 31a can be electrically controlled.
The motor 31 is fixed to the outer surface of the pressure regulating housing 21, and the shaft 31a penetrates into the pressure regulating chamber 22 side.
A spring receiving portion 31 b is provided at the tip of the shaft 31 a on the pressure adjusting hole 1 b side, and the spring receiving portion 31 b is connected to the motor side end of the pressure adjusting spring 26.

  The pressure receiving piston 25 is a member for receiving a pressure from the pressure chamber 16 and transmitting a force to the pressure adjusting spring 26, and is inserted into the pressure adjusting hole 1b. The diameter of the pressure receiving piston 25 is formed to be substantially equal to the inner diameter of the pressure adjusting hole 1b.

  The pressure adjusting spring 26 is a member that biases the outer rotor 5 to one side. In the present embodiment, the pressure adjusting spring 26 biases the outer rotor 5 in a direction parallel to the longitudinal direction. The pressure adjusting spring 26 is disposed in parallel with the longitudinal direction of the pressure adjusting chamber 22, and an end portion on the pressure adjusting hole 1 b side is connected to the pressure receiving piston 25.

  The motor 31 is connected to the control device 40. The control device 40 controls the amount of rotation of the motor 31, thereby changing the urging force of the pressure adjusting spring 26 to control the amount of movement of the outer rotor 5, thereby changing the displacement of the variable displacement pump 100. The control device 40 is, for example, an ECU (Engine Control Unit), and calculates the operation amount of the motor 31 based on the engine speed, the engine load, the hydraulic oil temperature, the water temperature, and the like input to the control device 40. Output to the motor 31.

  Next, the movement of the variable displacement pump 100 during control will be described.

  First, the discharge hydraulic pressure P of the variable displacement pump 100 is determined by the required hydraulic pressure in each part of the engine. The required oil pressure changes stepwise according to the engine speed N. Moreover, it changes according to engine load, hydraulic oil temperature, water temperature, and the like. In the present embodiment, the required oil pressure with respect to the engine speed N at low load is expressed as P1, and the required oil pressure with respect to the engine speed N at high load is expressed as P2. In FIG. 3, a line representing P1 is a thick line, and a line representing P2 is a thin line. Here, the required oil pressure P1 will be described. For example, when the engine speed N is low (from N1 to N2 in the figure), the required oil pressure is calculated only from the required value from the cam, so the pressure of P11 in FIG. 3 is sufficient. Further, as shown in FIG. 3, in N3, when an oil jet is used for piston cooling, the required oil pressure is P12. Thus, it is necessary to change the volume of the variable displacement pump 100 so that the operating oil pressure is suitable for the required oil pressure P1 that changes according to the engine speed N or the like.

Next, control of the motor of the variable displacement pump 100 at the required hydraulic pressure P1 will be described.
At the time of starting the engine, as shown in FIG. 1, the outer rotor 5 is disposed so as to be in contact with the side surface of the housing 1 opposite to the side surface having the pressure adjusting hole 1b. The hydraulic oil chamber 15 of the variable displacement pump 100 is configured to have a maximum volume. In the present embodiment, this state is the maximum capacity.

At this time, a discharge oil pressure P is applied to the pressure chamber 16, and a force fpd formed by the product of the pressure receiving area S and the discharge oil pressure P is applied to the pressure receiving piston 25 penetrating the pressure adjusting hole 1b in the direction of arrow A. Take it. With respect to this force, the urging force fsp of the pressure adjusting spring 26 is applied in the direction of arrow B, which is the direction opposite to the direction of arrow A. At this time, the shaft 31a is extended to the maximum length so that the urging force fsp is larger than the force fpd formed by the product of the pressure receiving area S and the discharge hydraulic pressure P.
The biasing force of the pressure adjustment spring 26 when the shaft 31a is extended to the maximum length is set to fsp0.
When the engine speed N increases, the amount of discharged oil increases, so the discharge hydraulic pressure also increases in proportion to the increase in the engine speed N.

When the engine speed N reaches N1, the motor 31 is driven to move the shaft 31a in a direction that reduces the urging force fsp of the pressure adjusting spring 26. In other words, the biasing force of the pressure adjusting spring 26 is reduced to fsp1 by shortening the shaft 31a toward the motor 31 side.
With this configuration, the force fpd applied to the pressure receiving piston 25 inserted into the pressure adjusting hole 1b is larger than the biasing force fsp1 of the pressure adjusting spring 26, so that the outer rotor 5 is adjusted as shown in FIG. It moves to the side of the pressure hole 1b. For this reason, the volume of the hydraulic oil chamber 15 decreases, and the discharge hydraulic pressure decreases. At this time, the biasing force fsp1 of the pressure adjusting spring 26 is set so that the discharge hydraulic pressure P does not exceed the required hydraulic pressure P11. Thereby, it is possible to prevent excessive hydraulic oil from being supplied to each part of the engine when the engine is running at a low speed.

When the engine speed N reaches N2, the motor 31 is driven to move the shaft 31a in a direction that increases the urging force fsp of the pressure adjusting spring 26. In other words, the urging force of the pressure adjusting spring 26 is increased to fsp2 by extending the shaft 31a toward the pressure adjusting hole 1b. fsp2 is a smaller value than fsp0.
By configuring in this way, the force fpd applied to the pressure receiving piston 25 penetrating into the pressure adjusting hole 1b is smaller than the urging force fsp2 of the pressure adjusting spring 26, so that the outer rotor 5 has a side surface with the pressure adjusting hole 1b. Moves to the opposite side. For this reason, the volume of the hydraulic oil chamber 15 increases and the discharge hydraulic pressure P increases. The biasing force fsp2 of the pressure adjusting spring is set so that the discharge hydraulic pressure P increases to the required hydraulic pressure P12 when using the oil jet. Thereby, when using an oil jet, an appropriate amount of hydraulic oil can be supplied to each part of the engine.

  Further, until the engine speed N shifts from N2 to N3, the discharge oil amount increases in proportion to the increase in the engine speed because the discharge oil amount increases as the engine speed N increases.

When the engine speed reaches N3, the motor 31 is driven to move the shaft 31a in the direction in which the biasing force fsp of the pressure adjusting spring 26 is increased. In other words, the biasing force of the pressure adjusting spring 26 is increased to fsp3 by extending the shaft 31a toward the pressure adjusting hole 1b. fsp3 is a smaller value than fsp0.
By configuring in this way, the force fpd applied to the pressure receiving piston 25 penetrating into the pressure adjusting hole 1b is smaller than the urging force fsp3 of the pressure adjusting spring 26, so that the outer rotor 5 has a side surface with the pressure adjusting hole 1b. Moves to the opposite side. For this reason, the volume of the hydraulic oil chamber 15 increases and the amount of discharged oil increases. Thereby, an appropriate amount of hydraulic oil can be supplied to each part of the engine.

  Further, since the amount of discharged oil increases as the engine speed N increases until the engine speed shifts from N3 to N4, the discharge hydraulic pressure P also increases in proportion to the increase in the engine speed N. Then, at a constant discharge hydraulic pressure, the force fpd applied to the pressure receiving piston that has penetrated the pressure adjusting hole balances with the urging force fsp3 of the pressure adjusting spring 26, so that the amount of discharged oil is fixed.

Next, a variable displacement pump 200 according to another embodiment of the present invention will be described.
In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals.

A variable displacement pump 200 according to another embodiment of the present invention is a device that is provided in a cylinder block or the like of an engine (not shown) and supplies hydraulic oil to each part of the engine.
4 and 5, the variable displacement pump 200 includes a housing 101, a drive shaft 2, an inner rotor 3, a vane 4, an outer rotor 5, a pressure chamber 116, a pressure regulating chamber 122, Is provided.

  The housing 101 is a container that stores therein the drive shaft 2, the inner rotor 3, the vane 4, the outer rotor 5, the pressure receiving piston 25, and the pressure adjusting spring 26 as an urging member. That is, the housing 101 includes a pressure chamber 116 and a pressure regulating chamber 122. In the present embodiment, the housing 101 is configured by a portion configured in a substantially rectangular shape in plan view and a portion connected to a side surface of the portion configured in the rectangular shape. A substantially rectangular space is formed inside the rectangular portion of the housing 101, and screw holes 101a for connecting to a cylinder block (not shown) are formed at the four corners of the outer periphery in plan view. Is provided. Further, a pressure regulating chamber 122 is formed in a portion connected to the side surface of the portion of the housing 101 that is formed in a rectangular shape. The pressure regulating chamber 122 is configured to communicate with the pressure chamber 116 provided inside the housing 101. The pressure adjusting chamber 122 stores a pressure receiving piston 25 and a pressure adjusting spring 26 as an urging member, and a motor 31 as a pressure adjusting mechanism is provided at the end of the pressure adjusting chamber 122 opposite to the pressure chamber 116. Is provided.

  The drive shaft 2 is a shaft that rotates the inner rotor 3 by a rotational force transmitted from a power transmission shaft such as a crankshaft (not shown), and is rotatably supported by the housing 101. One end of the drive shaft 2 is connected to the power transmission shaft.

  The inner rotor 3 is coupled to the drive shaft 2 and rotates together with the drive shaft 2. The inner rotor 3 is provided on a concentric circle of the drive shaft 2, and a plurality of slits 11 are notched radially from the inner center side to the radially outer side. A back pressure chamber 12 having a substantially circular cross section for introducing hydraulic oil is provided at the inner base end of each slit 11.

The vane 4 is accommodated in the slit 11 so that it can be taken in and out. In the vane 4, each front end surface on the outer peripheral side abuts on the inner peripheral surface of the outer rotor 5, and each front end surface on the inner peripheral side abuts on the outer peripheral surface of the ring member 13.
The ring member 13 is a member that prevents the vane 4 from moving toward the inner peripheral side by abutting with the inner peripheral side tip portion of the vane 4, is formed in a cylindrical shape, and is provided inside the inner rotor 3. . The tip of the inner peripheral side of the vane 4 is in contact with the outer peripheral surface of the ring member 13.

  The outer rotor 5 is arranged so as to be eccentric with respect to the inner rotor 3. The inner peripheral surface of the outer rotor 5 is formed in a circular shape in plan view, and the outer front end surface of the vane 4 is in contact with the inner peripheral surface. By comprising in this way, the outer peripheral surface of the inner rotor 3, the inner surface of the adjacent vane 4, the inner peripheral surface of the outer rotor 5, and both the bottom surfaces of the housing 101 are liquid-tightly divided and surrounded by each. The space becomes the hydraulic oil chamber 15.

In addition, the outer peripheral surface of the outer rotor 5, the inner peripheral surface of the portion of the housing 101 formed in a square shape, and both bottom surfaces of the housing 101 are partitioned, and each enclosed space serves as one pressure chamber 116.
Outside pressure is introduced into the pressure chamber 116. Thereby, the atmospheric pressure is uniformly applied to the outer peripheral surface of the outer rotor 5.

Next, the pressure regulating mechanism according to the present embodiment will be described.
In the present embodiment, the pressure adjusting mechanism is configured by a motor 31.
The motor 31 has a shaft 31 a and is a device that expands and contracts the shaft 31 a in the longitudinal direction of the pressure regulating chamber 122 stepwise. In the present embodiment, the motor 31 is a stepping motor, and by performing the motor 31 and the control device 40, the expansion / contraction amount of the shaft 31a can be electrically controlled.
The motor 31 is fixed to the outer surface of the portion of the housing 101 where the pressure regulating chamber 122 is provided, and the shaft 31a penetrates into the pressure regulating chamber 122 side.
A spring receiving portion 31 b is provided at the tip of the shaft 31 a on the pressure chamber 116 side, and the spring receiving portion 31 b is connected to the motor side end portion of the pressure adjusting spring 26.

  The pressure adjusting spring 26 is a member that biases the outer rotor 5 to one side. In the present embodiment, the pressure adjusting spring 26 biases the outer rotor 5 in a direction parallel to the longitudinal direction. The pressure adjusting spring 26 is disposed in parallel with the longitudinal direction of the pressure adjusting chamber 122, and an end portion on the pressure chamber 116 side is in contact with the side surface of the outer rotor 5.

  The motor 31 is connected to the control device 40. The control device 40 controls the amount of rotation of the motor 31, thereby changing the biasing force of the pressure adjusting spring 26 to control the amount of movement of the outer rotor 5, thereby changing the displacement of the variable displacement pump 200. The control device 40 is, for example, an ECU (Engine Control Unit), and calculates the operation amount of the motor 31 based on the engine speed N, the engine load, the hydraulic oil temperature, the water temperature, and the like input to the control device 40. And output to the motor 31.

  By comprising in this way, since the movement amount of the outer rotor 5 can be controlled, without providing a pressure receiving piston, the number of parts can be saved.

In the variable displacement engine according to the present embodiment, the urging member is configured by a pressure adjusting spring, but the present invention is not limited to this, and any member that generates an urging force may be used. For example, the urging member can be configured by a leaf spring.

  Further, in the present embodiment, the pressure adjusting chamber is provided on the side of the housing 1, but the present invention is not limited to this. For example, the pressure adjusting chamber may be provided in a part of the pressure chamber 16 of the housing 1. is there.

  In the present embodiment, the required oil pressure with respect to the engine speed N at the time of low load is P1, but the present invention is not limited to this. For example, when it is necessary to supply hydraulic oil to the crank journal, it is necessary to increase the required oil pressure at a predetermined engine speed higher than P1.

As described above, the variable displacement pump 100 is formed radially on the housing 1, the drive shaft 2 rotatably supported on the housing 1, the inner rotor 3 coupled to the drive shaft 2, and the inner rotor 3. A vane 4 accommodated in the slit 11 so as to be able to be taken in and out; an outer rotor 5 which is arranged eccentrically with respect to the inner rotor 3 and forms the hydraulic oil chamber 15 together with the inner rotor 3 and the vane 4; A pressure chamber 16 provided on the surface; a pressure adjusting spring 26 that urges the outer rotor 5 in an eccentric direction; a motor 31 as a pressure adjusting mechanism that changes the urging force of the pressure adjusting spring 26; And a control device 40 for controlling.
With this configuration, the volume of the hydraulic oil chamber 15 can be increased or decreased by changing the biasing force of the pressure adjusting spring 26 by the motor 31, so that the discharge hydraulic pressure or the atmospheric pressure is applied to the two pressure chambers. This eliminates the need for a hydraulic pressure adjusting mechanism such as an oil passage or a hydraulic actuator, thereby simplifying the mechanism. Further, by changing the urging force of the pressure adjusting spring 26 while controlling the drive of the motor 31 by the control device 40, the capacity of the variable displacement pump 100 can be changed according to the required oil amount.

The motor 31 is connected to the end of the pressure adjusting spring 26 and changes the biasing force by expanding and contracting the pressure adjusting spring 26.
With this configuration, the urging force of the pressure adjusting spring 26 can be continuously changed by controlling the driving of the motor 31 by the control device 40, and the variable displacement pump 100 can be changed according to the required oil amount. The capacity of the battery can be continuously changed.

DESCRIPTION OF SYMBOLS 1 Housing 2 Drive shaft 3 Inner rotor 4 Vane 5 Outer rotor 11 Slit 15 Hydraulic oil chamber 16 Pressure chamber 26 Pressure regulation spring (biasing member)
31 Motor (pressure adjustment mechanism)
40 Control means

Claims (2)

A housing; a drive shaft rotatably supported by the housing; an inner rotor coupled to the drive shaft; a vane accommodated in a slit formed radially in the inner rotor; and the inner An outer rotor that is arranged to be eccentric with respect to the rotor and forms a hydraulic oil chamber together with the inner rotor and the vane, a pressure chamber provided on an outer peripheral surface of the outer rotor, and a direction in which the outer rotor is eccentric. An urging member that urges, a pressure adjusting mechanism that changes the urging force of the urging member, and a control device that controls driving of the pressure adjusting mechanism.
A variable displacement pump characterized by that. The pressure adjusting mechanism is configured by a motor, and the motor is connected to an end of the urging member, and the urging force is changed by expanding and contracting the urging member.
The variable displacement pump according to claim 1.

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