阅读说明：本技术 一种具有排量反馈控制的变量斜盘式轴向柱塞泵 (Variable swash plate type axial plunger pump with displacement feedback control ) 是由 沈伟 赵海鸣 潘静娴 李震 陈振豪 于 2021-08-09 设计创作，主要内容包括：本发明属于柱塞泵技术领域,提供了一种具有排量反馈控制的变量斜盘式轴向柱塞泵,包括泵本体、与泵本体滑动连接的变量活塞、用于调节变量活塞的位移的电控压油阀、用于将变量活塞的水平位移转换为斜面位移转换块的纵向位移的斜面位移转换块、用于检测纵向位移并将纵向位移转换成反馈信号的位移传感器、在变量活塞的带动下同步运动的斜盘、在斜盘的带动下同步运动的至少一个柱塞、与对应的柱塞滑动连接的缸套、与缸套固定连接的一个回弹机构以及用于接收反馈信号的控制器。本发明具备结构简单紧凑,控制灵敏度高,能够精确测量斜盘式柱塞泵排量,且使用寿命长,能够安静的无振动运行,可以非常经济的制造等优点。(The invention belongs to the technical field of plunger pumps, and provides a variable swash plate type axial plunger pump with displacement feedback control, which comprises a pump body, a variable piston connected with the pump body in a sliding manner, an electric control oil pressure valve used for adjusting the displacement of the variable piston, an inclined plane displacement conversion block used for converting the horizontal displacement of the variable piston into the longitudinal displacement of the inclined plane displacement conversion block, a displacement sensor used for detecting the longitudinal displacement and converting the longitudinal displacement into a feedback signal, a swash plate synchronously moving under the driving of the variable piston, at least one plunger synchronously moving under the driving of the swash plate, a cylinder sleeve connected with the corresponding plunger in a sliding manner, a rebound mechanism fixedly connected with the cylinder sleeve, and a controller used for receiving the feedback signal. The invention has the advantages of simple and compact structure, high control sensitivity, capability of accurately measuring the displacement of the swash plate type plunger pump, long service life, capability of quiet vibration-free operation, capability of being manufactured economically and the like.)

1. A variable capacity swash plate axial piston pump with displacement feedback control, comprising:

a pump body;

the variable piston is positioned in the pump body and is in sliding connection with the pump body;

the electrically controlled oil pressure valve is used for adjusting the displacement of the variable piston;

the inclined displacement conversion block is integrally formed with the top end of the variable piston and is used for converting the horizontal displacement of the variable piston into the longitudinal displacement of the inclined displacement conversion block;

the displacement sensor is contacted with the upper surface of the inclined displacement conversion block and is used for detecting the longitudinal displacement and converting the longitudinal displacement into a feedback signal;

the swash plate is positioned in the pump body, is rotationally connected with the variable piston and synchronously moves under the driving of the variable piston;

the plunger is positioned in the pump body, is connected with the swash plate and is used for synchronously moving under the driving of the swash plate;

the cylinder sleeves correspond to the plungers one by one and are connected with the corresponding plungers in a sliding manner;

the at least one rebounding mechanism corresponds to the cylinder sleeves one by one, and one end of the rebounding mechanism is fixedly connected with the cylinder sleeves;

and the controller is in communication connection with the displacement sensor and is used for receiving the feedback signal.

2. A variable capacity swash plate type axial plunger pump with displacement feedback control as claimed in claim 1, wherein:

the cylinder sleeve is made of alloy steel, is cylindrical and is communicated with the pump body.

3. A variable capacity swash plate type axial plunger pump with displacement feedback control as claimed in claim 2, wherein:

the inner wall of one end, far away from the plunger, of the cylinder sleeve is provided with a plurality of annular grooves distributed along the circumferential direction of the cylinder sleeve.

4. A variable capacity swash plate type axial plunger pump with displacement feedback control as claimed in claim 1, wherein:

wherein the variable piston is rotationally connected with the swash plate through a driving arm and a spherical guide seat, the spherical guide seat is fixedly connected with the side wall of the variable piston,

one end of the driving arm is provided with a ball socket, the other end is provided with a pressure head,

the ball socket is hinged with the spherical guide seat, and the pressure head is detachably connected with the swash plate.

5. A variable displacement feedback controlled variable swash plate axial piston pump according to claim 4, further comprising:

a first buckling and pressing groove forming block and a second buckling and pressing groove forming block,

the pressure head is fixed in the mounting hole by the aid of the first buckling and pressing groove forming block and the second buckling and pressing groove forming block, and the upper surface of the pressure head is flush with the upper surface of the swash plate.

6. A variable displacement feedback controlled variable swash plate axial piston pump according to claim 4, wherein:

wherein the pressure head has an oblique angle, and the mounting hole has an oblique surface matching the oblique angle.

7. A variable capacity swash plate type axial plunger pump with displacement feedback control as claimed in claim 1, wherein:

the top end of the inclined plane displacement conversion block is an inclined plane.

8. A variable capacity swash plate type axial plunger pump with displacement feedback control as claimed in claim 1, wherein:

the electric control oil pressure valve is a servo valve FF-106A/103, and the displacement sensor is an IW-03-01 induction linear displacement sensor.

9. A variable capacity swash plate type axial plunger pump with displacement feedback control as claimed in claim 1, wherein:

one end of the swash plate is connected with the pump body through an elastic piece, and the other end of the swash plate is rotatably connected with the variable piston.

10. A variable capacity swash plate axial piston pump with displacement feedback control as claimed in claim 1, further comprising:

a rotating shaft is arranged on the rotating shaft,

one end of the rotating shaft is fixedly connected with the swash plate, and the plungers are respectively fixedly connected with the swash plate and are uniformly distributed around the rotating shaft along the circumferential direction of the rotating shaft.

Technical Field

The invention belongs to the technical field of plunger pumps, and particularly relates to a variable swash plate type axial plunger pump with displacement feedback control.

Background

Swash plate plunger pumps are used in a very wide range of industrial markets. The displacement is the most basic function of the variable mechanism, namely, the displacement of the pump is proportional to a control signal by utilizing the position control effect of the variable mechanism, and other control functions are realized based on the function. However, the hydraulic pumps on the market rarely achieve precise control of their own displacement. The existing swash plate type plunger pump generally has the technical problems that the control sensitivity is low, a customer cannot accurately adjust the discharge capacity of the pump according to the use working condition, the inner space of the swash plate type plunger pump is limited, and the like. To obtain accurate displacement, the flow is typically measured by means of an external flow meter, and since the motor speed is known and the displacement is calculated from the flow and motor speed, the displacement can be back-inferred. Although this method is easy to operate, it is time-consuming and labor-intensive. At present, the displacement sensors are arranged on two sides of a variable cylinder, so that the feedback of the pump displacement and the displacement sensors has the problem of large error, and a large enough space is reserved between the variable cylinder and a shell for mounting the displacement sensors, so that the volume of a plunger pump is increased or the mounting difficulty of the displacement sensors is high.

Disclosure of Invention

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a variable displacement swash plate type axial plunger pump with displacement feedback control, which is capable of accurately measuring the displacement of the swash plate type axial plunger pump.

The present invention provides a variable swash plate type axial plunger pump with displacement feedback control, having the characteristics that: a pump body; the variable piston is positioned in the pump body and is in sliding connection with the pump body; the electrically controlled oil pressure valve is used for adjusting the displacement of the variable piston; the inclined plane displacement conversion block is integrally formed with the top end of the variable piston and is used for converting the horizontal displacement of the variable piston into the longitudinal displacement of the inclined plane displacement conversion block; the displacement sensor is contacted with the upper surface of the inclined plane displacement conversion block and is used for detecting longitudinal displacement and converting the longitudinal displacement into a feedback signal; the swash plate is positioned in the pump body, is rotationally connected with the variable piston and synchronously moves under the driving of the variable piston; the plunger is positioned in the pump body, is connected with the swash plate and is used for synchronously moving under the driving of the swash plate; the cylinder sleeves correspond to the plungers one by one and are connected with the corresponding plungers in a sliding manner; the at least one rebounding mechanism corresponds to the cylinder sleeves one by one, and one end of the rebounding mechanism is fixedly connected with the cylinder sleeves; and the controller is in communication connection with the displacement sensor and is used for receiving the feedback signal.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: wherein, the cylinder liner is made of alloy steel, is cylindrical and is communicated with the pump body.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: the inner wall of one end, far away from the plunger, of the cylinder sleeve is provided with a plurality of annular grooves distributed along the circumferential direction of the cylinder sleeve.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: the variable piston is rotatably connected with the swash plate through a driving arm and a spherical guide seat, the spherical guide seat is fixedly connected with the side wall of the variable piston, one end of the driving arm is provided with a ball socket, the other end of the driving arm is provided with a pressure head, the ball socket is hinged with the spherical guide seat, and the pressure head is detachably connected with the swash plate.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, it may further have a feature that: the pressing device comprises a pressing groove forming block I and a pressing groove forming block II, wherein a mounting hole is formed in the swash plate, the pressing head is fixed in the mounting hole through the pressing groove forming block I and the pressing groove forming block II, and the upper surface of the pressing head is flush with the upper surface of the swash plate.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: wherein, the pressure head has the bevel angle, and the mounting hole has the inclined plane that matches with the bevel angle.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: the top end of the inclined displacement conversion block is an inclined surface, and the bottom of the inclined displacement conversion block and the middle of the variable piston are integrally formed.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: wherein, the electric control oil pressure valve is a servo valve FF-106A/103, and the displacement sensor is an IW-03-01 induction linear displacement sensor.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, the variable swash plate type axial plunger pump may further have the following features: one end of the swash plate is connected with the pump body through an elastic piece, and the other end of the swash plate is rotatably connected with the variable piston.

In the variable swash plate type axial plunger pump with displacement feedback control provided by the present invention, it may further have a feature that: the rotating shaft, wherein, the one end and the sloping cam plate fixed connection of rotating shaft, a plurality of plungers respectively with sloping cam plate fixed connection and along the circumference evenly distributed around the rotating shaft of rotating shaft.

Action and Effect of the invention

According to the variable swash plate type axial plunger pump with displacement feedback control, a controller can input a control signal in advance, the movement of the variable piston can drive the connected swash plate to move according to the displacement of the control variable piston through the electric control oil pressing valve, so that the inclination angle of the swash plate is changed, and the plunger is driven to move back and forth when the angle of the swash plate is changed, so that the flow output of the pump can be realized.

Each cylinder sleeve is independently provided with a rebound mechanism, so that the structure of the plunger pump is compact, the pulling force of the sliding shoes on the plunger is eliminated, the abrasion is reduced, the stability is improved, and the service life of the pump is prolonged; this also greatly reduces cost and processing difficulty.

The inclined angle of the swash plate is changed by the movement of the variable piston through the connecting mechanism, on the other hand, because the variable piston is integrally formed with the inclined displacement conversion block, when the variable piston moves horizontally, the inclined displacement conversion block can be driven to move, so that the upper surface of the inclined displacement conversion block generates longitudinal displacement, and the displacement sensor is in contact with the inclined displacement conversion block, so that the longitudinal displacement can be measured, and the horizontal displacement of the variable piston can be calculated in equal proportion. And then the displacement sensor converts the displacement change into a feedback signal which is transmitted to an external controller, the feedback signal is compared with an input control signal to obtain a deviation signal, and an electrically controlled oil pressure valve is controlled, so that a closed-loop position control system is formed, the displacement of the swash plate type plunger pump is kept near a set value, and the closed-loop displacement control based on variable piston position feedback is realized.

In summary, the present embodiment has the advantages of simple and compact structure, high control sensitivity, capability of accurately measuring the displacement of the swash plate type plunger pump, long service life, capability of quiet vibration-free operation, very economical manufacture, etc.

Drawings

FIG. 1 is a schematic structural view of a pump body in an embodiment of the invention;

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a schematic view showing the installation relationship of the variable displacement piston, the inclined displacement conversion block, the displacement sensor, the connection mechanism and the swash plate in the embodiment of the present invention;

FIG. 4 is a schematic illustration of the cylinder liner and plunger mounting relationship in an embodiment of the present invention;

FIG. 5 is a schematic diagram of a variable displacement piston and a ramp displacement conversion block from different perspectives in an embodiment of the present invention;

FIG. 6 is a schematic diagram showing the installation positions of the variable piston, the inclined plane displacement conversion block and the displacement sensor in the embodiment of the present invention; and

fig. 7 is a schematic diagram of the positions of the variable displacement piston, the ramp displacement conversion block and the position sensor during movement in an embodiment of the present invention.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the variable swash plate type axial plunger pump with the displacement feedback control is concretely described below by combining the embodiment and the attached drawings.

< example >

The present embodiment is specifically described for a variable swash plate type axial plunger pump with displacement feedback control.

FIG. 1 is a schematic structural view of a pump body in an embodiment of the invention; FIG. 2 is a left side view of FIG. 1; FIG. 3 is a schematic view showing the installation relationship of the variable displacement piston, the inclined displacement conversion block, the displacement sensor, the connection mechanism and the swash plate in the embodiment of the present invention; FIG. 4 is a schematic illustration of the cylinder liner and plunger mounting relationship in an embodiment of the present invention; FIG. 5 is a schematic diagram of a variable displacement piston and a ramp displacement conversion block from different perspectives in an embodiment of the present invention; fig. 6 is a schematic view showing the installation position relationship of the variable piston, the inclined plane displacement conversion block and the displacement sensor in the embodiment of the present invention. In fig. 5, (a), (b), and (c) are front, left, and top views of the variable piston, respectively.

As shown in fig. 1 to 6, the swash plate type plunger pump includes a pump body 10, a variable piston 20, a slope displacement conversion block 30, a displacement sensor 40, a transition plate 50, an electrically controlled oil pressure valve (not shown), a swash plate 60, a spherical guide seat 71, a driving arm 72, a first press-fitting groove forming block 81 and a second press-fitting groove forming block 82, a plunger 91, a cylinder sleeve 92, a rebound mechanism 93, a rotating shaft 94, a shoe 95, and a controller (not shown).

The pump body 10 contains hydraulic oil, and has a variable piston mounting portion 11 and a swash plate and plunger mounting portion 12. The pump body 10 is formed by reinforced nylon material in one step, and can be recycled, so that the cost can be saved.

The variable piston 20 is installed at the variable piston installation position 11, the upper end of the variable piston is connected with the variable piston hole on the pump body 10 in a sliding mode, and the rest part of the variable piston is located in the pump body 10 and moves left and right under the pushing of hydraulic pressure.

The variable piston 20 includes a first cylinder 21, a second cylinder 22, and a partition block 23 separating the first cylinder 21 and the second cylinder 22, which are not communicated with each other.

An electrically controlled oil pressure valve is installed on the pump body 10 for adjusting the displacement of the variable piston 20. The electrically controlled oil pressing valve is respectively communicated with the corresponding oil passages of the first cylinder body 21 and the second cylinder body 22, and controls the oil supply amount of the oil passages. When the oil amount in the first and second cylinders 21 and 22 changes, the hydraulic pressure changes, and thus the variable piston 20 moves left and right. In the embodiment, the electrically controlled hydraulic oil valve adopts a high-precision servo valve FF-106A/103.

The top end of the inclined displacement conversion block 30 is an inclined surface, the bottom of the inclined displacement conversion block is integrally formed with the middle of the variable piston 20, and the horizontal displacement of the variable piston 20 caused by the horizontal displacement is converted into the longitudinal displacement of the variable piston.

The inclined plane displacement conversion block 30 and the variable piston 20 are cast and molded at one time to form a whole, the displacement of the swash plate type plunger pump can be accurately measured, the service life is long, and the pump can run quietly without vibration.

The displacement sensor 40 is an IW-03-01 linear induction displacement sensor and is fixedly installed on the pump body 10, and the transition plate 50 is fixed on the pump body.

The bottom end of the displacement sensor 40 is in contact with the upper surface of the inclined displacement conversion block 30, detects the longitudinal displacement of the inclined displacement conversion block 30, and converts the longitudinal displacement into a feedback signal.

The displacement sensor 40 reflects the displacement of the variable displacement piston 20 during displacement calibration, but in actual operation, reflects the displacement of the plunger pump. This is because, in actual operation, after the displacement sensor 40 is mounted, the displacement corresponding to the unit displacement of the displacement sensor 40 is first tested, so that the unit displacement corresponds to the displacement, and thus, the longitudinal displacement of the displacement sensor 40 is reflected as the feedback of the displacement.

The controller is in communication connection with the electric control oil pressure valve and the displacement sensor 40 respectively, can input control signals and also receives feedback signals of the displacement sensor 40.

The swash plate 60 and the plungers are located at the swash plate and plunger mounting position 12 in the pump body.

One end of the swash plate 60 is connected to the pump body 10 through an elastic member 61, and the other end is rotatably connected to the variable piston 20. In the present embodiment, the elastic member 61 is a spring. The upper end of the swash plate 60 has a mounting hole.

The swash plate 60 is rotatably connected to the variable pistons 20 via the spherical guide seats 71 and the driving arms 72, and is driven by the variable pistons 20 to move synchronously. The plunger is fixedly connected with the swash plate 60 and moves under the driving of the swash plate 60. In this embodiment, a slipper 95 is provided between the swash plate and the plunger.

The spherical guide seat 71 is fixedly connected with the side wall of the variable piston 20. The drive arm 72 has a ball socket at one end and a ram at the other end. The pressure head is provided with an oblique angle alpha, and the mounting hole is internally provided with an inclined surface matched with the oblique angle. The ball socket is hinged with the spherical guide seat 71, and the pressure head is detachably connected with the swash plate. The first buckling and pressing groove forming block 81 and the second buckling and pressing groove forming block 82 are inserted into the mounting hole respectively, the pressing heads are fixed in the mounting hole through mutual clamping, and the upper surfaces of the pressing heads are flush with the upper surface of the swash plate. The first buckling and pressing groove forming block 81 and the second buckling and pressing groove forming block 82 are provided with slopes which are matched with the slopes in the mounting hole.

The rotating shaft 94 is cylindrical and has one end fixedly connected to the swash plate 60. The 9 plungers 91 are respectively fixedly connected with the swash plate 60 and evenly distributed around the rotating shaft along the circumferential direction of the rotating shaft.

Each plunger 91 is slidably connected to one of the cylinder liners 92. The plunger 91 has a plunger bore 911. The cylinder liner 92 is made of alloy steel, and has a cylindrical shape, and communicates with the pump body 20.

The inner wall of the cylinder 92 at the end remote from the plunger 91 has a plurality of annular grooves 921 distributed along the circumference of the cylinder 92. The annular groove 921 can achieve buffering of the oil.

The resilient mechanism 93 is a spring, one end of which is fixedly connected to the inner wall of the cylinder 92, and the other end of which is grounded to the end of the cylinder 92 when the plunger 91 slides in the cylinder 92. The resilience mechanism assists the acting force of hydraulic oil to determine the position of the plunger by means of the elasticity and the resilience of the spring, so that the plunger is prevented from being stuck and the like, and meanwhile, the resilience mechanism also has a damping effect.

When the variable piston 20 moves horizontally, the swash plate 60 is rotationally connected with the variable piston 20 through the connecting mechanism, so that the swash plate 60 is driven to move, and the swash plate tilts a certain angle. The output displacement of the swash plate type plunger pump is changed by controlling the movement of the plunger through the one-to-one correspondence relationship between the positions of the variable pistons 20 and the angles of the swash plate 60.

Fig. 7 is a schematic diagram of the positions of the variable displacement piston, the ramp displacement conversion block and the displacement sensor during movement in an embodiment of the present invention. In fig. 7, (a), (b), and (c) are schematic diagrams of positions of the variable piston moving to the right, in the middle, and in the left, respectively.

As shown in fig. 3 and 7, when the bottom end of the displacement sensor 40 is located directly above the slope displacement conversion block 30 (see (b) in fig. 7), the reading of the displacement sensor 40 is zero, and the reading of the displacement sensor 40 is a negative number (see (a) in fig. 7) or a positive number (see (c) in fig. 7) as the slope displacement conversion block 30 moves. Therefore, the displacement sensor 40 can be proportionally corresponding to the horizontal displacement of the variable piston 20 by measuring the longitudinal displacement of the inclined displacement conversion block 30, and here, because the response frequency of the displacement sensor 40 is far greater than that of the controller, the displacement sensor 40 can be approximately regarded as a proportional amplifier, the displacement change is converted into a feedback signal and transmitted to the controller, and compared with an input control signal, a deviation signal is obtained to control the electrically controlled oil pressure valve, so that a closed-loop position control system is formed, the displacement of the swash plate type plunger pump is kept near a set value, and the closed-loop displacement control based on the variable piston position feedback is realized.

Effects and effects of the embodiments

According to the variable swash plate type axial plunger pump with displacement feedback control, a controller can input a control signal in advance, the movement of the variable piston can drive the movement of the connected swash plate through the electric control oil pressing valve according to the displacement of the control variable piston, so that the inclination angle of the swash plate is changed, and the plunger is driven to move back and forth when the angle of the swash plate is changed, so that the flow output of the pump can be realized.

Each cylinder sleeve is independently provided with a rebound mechanism, so that the structure of the plunger pump is compact, the pulling force of the sliding shoes on the plunger is eliminated, the abrasion is reduced, the stability is improved, and the service life of the pump is prolonged; this also greatly reduces cost and processing difficulty.

The inclined angle of the swash plate is changed by the movement of the variable piston through the connecting mechanism, on the other hand, because the variable piston is integrally formed with the inclined displacement conversion block, when the variable piston moves horizontally, the inclined displacement conversion block can be driven to move, so that the upper surface of the inclined displacement conversion block generates longitudinal displacement, and the displacement sensor is in contact with the inclined displacement conversion block, so that the longitudinal displacement can be measured, and the horizontal displacement of the variable piston can be calculated in equal proportion. And then the displacement sensor converts the displacement change into a feedback signal which is transmitted to an external controller, the feedback signal is compared with an input control signal to obtain a deviation signal, and an electrically controlled oil pressure valve is controlled, so that a closed-loop position control system is formed, the displacement of the swash plate type plunger pump is kept near a set value, and the closed-loop displacement control based on variable piston position feedback is realized.

The displacement sensor is reasonably arranged in the middle of the variable piston, and can be used for measuring the longitudinal displacement of the inclined displacement conversion block on the premise of not increasing the volume of the pump body, so that the displacement sensor can be used for measuring the horizontal displacement of the variable cylinder in an equal proportion.

The embodiment adopts the improved use of the high-precision servo valve FF-106A/103 to improve the response speed of the plunger pump.

The variable piston and the inclined plane block above the variable piston are cast and formed at one time to form a whole, the displacement of the swash plate type plunger pump can be accurately measured, the service life is long, the pump can run quietly without vibration, and the pump can be manufactured economically;

the embodiment forms a closed-loop position control system, so that the displacement of the swash plate type plunger pump is kept near a set value, and closed-loop displacement control based on variable piston position feedback is realized;

in this embodiment, the bulb that links firmly with variable piston is laminated with the ball socket of actuating arm, the pressure equipment groove becomes one, pressure equipment groove becomes one and becomes the piece, it becomes downthehole on sloping cam plate upper portion to arrange respectively in the pressure equipment groove becomes one to become the piece, in the pressure equipment groove becomes one to become two, and with the laminating of the last plane of sloping cam plate, thereby drive the sloping cam plate and rotate, the angle of control sloping cam plate, in order to obtain the position of variable jar and the relation of sloping cam plate angle one-to-one, and then the motion of control plunger, reach the purpose that changes the output discharge capacity of sloping cam plate plunger pump.

The present embodiment provides a pump which is operated with a plurality of plungers, in particular with nine plungers, which has a particularly compact construction, is capable of providing a very uniform pump output, and ensures quiet vibration-free operation, and which can also be manufactured very economically.

The pump body of the plunger pump of the embodiment is formed by reinforced nylon materials in one step, and can be recycled, so that the cost can be saved.

In this embodiment, the hydraulic oil in the inner hole of the plunger enters the hydraulic oil groove on the surface of the plunger body, and stores a certain amount of hydraulic oil. When the plunger moves in the pump body, hydraulic oil in the hydraulic oil tank can form a wear-resistant oil layer, and the surface of the plunger is subjected to static pressure supporting effect, so that mechanical wear of the plunger is reduced, and the service life of the plunger is prolonged.

A sliding shoe is arranged between the swash plate and the fixed plunger, and a layer of oil film is formed between the contact surface of the sliding shoe and the swash plate by pressure oil, so that abrasion is reduced.

In this embodiment, when the rotating shaft rotates, the nine fixed plungers fixed to the rotating shaft also rotate along with the movement of the cylinder liner, so that the number of the plungers can be increased, and the axial force can be reduced. Each cylinder sleeve is independently provided with a rebound mechanism, so that the structure of the plunger pump is compact, the pulling force of the sliding shoes on the plunger is eliminated, and the service life of the pump is prolonged; thus, the cost and the processing difficulty can be greatly reduced; due to the existence of the rebound mechanism, the design of a central spring is cancelled, so that the pressed area of the plunger is changed into surface contact, the abrasion is reduced, and the stability is improved.

In summary, the present embodiment has the advantages of simple and compact structure, high control sensitivity, capability of accurately measuring the displacement of the swash plate type plunger pump, long service life, capability of quiet vibration-free operation, very economical manufacture, etc.

The above embodiments are preferred examples of the present invention, and are not intended to limit the scope of the present invention.