A new type of axial piston pump and its flow control structure and control method

Abstract

The application discloses a novel axial plunger pump and a flow control structure thereof, which comprises a front pump body, a middle pump body, a rear pump body and a three-position four-way reversing valve, the three-position four-way reversing valve is used for realizing the conversion connection of various flow control modes, the two ends of the middle pump body are assembled and connected with the front pump body and the rear pump body respectively, a single-chip microcomputer processor is fixedly installed at the top end of the middle pump body, a touch screen is integrated at the top end of the single-chip microcomputer processor, an oil distribution disc is assembled and connected in the touch screen, a cylinder body is assembled at one end of the oil distribution disc, plungers are assembled in plunger holes in the cylinder body, a piston channel is formed at the top end of the rear pump body, an inclination sensor and a piston rod are installed in the piston channel, the inclination sensor automatically monitors the inclination angle of a swash plate variable head, the single-chip microcomputer processor processes data according to a pressure-inclination-flow function relationship, adjusts the inclination angle of the swash plate variable head, further adjusts the flow, realizes intelligent control of the flow, and improves the high-end, intelligent and green levels.

Description

Technical Field

[0001] This invention relates to an axial piston pump, and more particularly to a novel axial piston pump and its flow control structure and control method, belonging to the technical field of axial piston pumps. Background Technology

[0002] Axial piston pumps are energy conversion elements in hydraulic systems and key functional components for realizing the movement of mechanical equipment. Their performance directly affects the working efficiency of the entire hydraulic system. They possess advantages such as high pressure, high power, and wide applicability, and are widely used in industries such as machinery, construction, transportation, aviation, and aerospace. They are one of the most frequently used hydraulic components in modern industrial production. However, in actual long-term use, axial piston pumps are prone to sudden failures due to physical factors such as time, temperature, and pressure, as well as chemical factors such as the medium and contaminants, and improper human operation.

[0003] A variable displacement pump is a type of pump that automatically adjusts its flow rate according to demand; its output flow rate changes automatically with variations in load. The main advantages of variable displacement pumps are: they ensure high system efficiency and stability through automatic pump output adjustment; they save energy; they reduce noise and vibration; and they extend equipment life.

[0004] Pneumatic technology uses air and inert gases as the working medium. Air supply is ample and cost-free. More importantly, air and inert gases do not pollute the surrounding environment; they are clean media. The most basic requirement for applying pneumatic technology is an air compressor. For applications where air compressors already exist for other purposes, applying pneumatic technology is even more convenient, environmentally friendly, and greener.

[0005] A modern industrial system is the material and technological foundation of a modern nation and an important vehicle for developing new productive forces. Traditional industries play a crucial role in the national economy and the construction of a modern industrial system. While actively cultivating strategic emerging industries and future industries, we cannot neglect or abandon traditional industries. With technological progress and changes in market demand, we must use new technologies to transform and upgrade traditional industries, enhancing their high-end, intelligent, and green levels, so that traditional industries can be revitalized. Summary of the Invention

[0006] The purpose of this invention is to provide a novel axial piston pump that realizes multiple flow control modes such as intelligent control, pneumatic variable flow, hydraulic variable flow, pressure-limiting variable flow, and metering pump, thereby improving its high-end, intelligent, and green level and solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a novel axial piston pump and its flow control structure, comprising a front pump body, an intermediate pump body, a rear pump body, and a three-position four-way reversing valve. The two ends of the intermediate pump body are respectively assembled and connected to the front pump body and the rear pump body. A ball bearing assembly is fixedly installed at one end of the inner cavity of the front pump body. An output shaft is assembled and connected inside the ball bearing assembly. A microcontroller processor is fixedly installed at the top of the intermediate pump body. A touch screen is integrated at the top of the microcontroller processor. An oil distribution plate is assembled and connected inside the intermediate pump body. A d1 blind hole and a d... Two through holes are provided. One end of the oil distribution plate is floatingly connected to the cylinder block. The cylinder block is mounted in the chamber of the intermediate pump body via bearings. Each plunger hole inside the cylinder block is fitted with a plunger. The plungers are closed thin-walled structures. One end of the output shaft is fixedly connected to a spring. One end of the spring is connected to a ball joint. One end of the ball joint is connected to a return plate. Multiple slipper heads are mounted on the surface of the return plate. These slipper heads are correspondingly connected to the plungers. One end of each slipper head is connected to a swashplate variable displacement head. The bottom end of the front pump body has an oil outlet, which is connected to the inlet of a three-way connector. One outlet of the three-way pipe connector is connected to the p1 oil inlet of the three-position four-way directional valve. The p2 air inlet of the three-position four-way directional valve is connected to the outlet of the proportional pressure reducing valve. The inlet of the proportional pressure reducing valve is connected to an external air source. The T port of the three-position four-way directional valve is connected to the oil tank. The A port of the three-position four-way directional valve is connected to the inlet of the pressure sensor. The outlet of the pressure sensor is connected to the inlet of the single-acting piston cylinder. A piston passage is provided at the top of the rear pump body. An inclination sensor and a piston rod are installed inside the piston passage. The upper end of the piston rod passes through the pump body and is connected to the... A single-acting piston cylinder has an inlet installed in its rod chamber. A pressure adjusting screw is threadedly connected to the top of the rodless chamber. A pressure adjusting spring seat is installed at the lower end of the pressure adjusting screw, and a pressure adjusting spring is installed at the lower end of the spring seat. A piston rod is installed at the lower end of the spring, and a shaft pin is connected to the lower end of the piston rod. The shaft pin is installed in the middle of the swashplate variable head. A sealing sleeve and a sealing end sleeve are fixedly installed at the top of the piston channel, both movably connected to the piston rod. A front end cover is fitted to one end of the front pump body, and a rear end cover is fitted to one end of the rear pump body.

[0008] As a preferred embodiment of the present invention, the single-acting piston cylinder, as a variable displacement drive mechanism, mainly consists of a pressure adjusting screw, a pressure adjusting spring seat, a pressure adjusting spring, and a piston rod. The top of the rodless chamber of the single-acting piston cylinder is connected to the pressure adjusting screw via a thread. A pressure adjusting spring seat is installed at the lower end of the pressure adjusting screw. A pressure adjusting spring is installed at the lower end of the pressure adjusting spring seat. A piston rod is installed at the lower end of the pressure adjusting spring. The rod chamber of the single-acting piston cylinder is equipped with an inlet.

[0009] As a preferred technical solution of the present invention, the flow control mechanism mainly consists of a single-acting piston cylinder, a shaft pin, a swashplate variable head, etc. A piston rod is installed at the lower end of the single-acting piston cylinder, and a shaft pin is connected to the lower end of the piston rod. The shaft pin is installed in the middle of the swashplate variable head.

[0010] As a preferred embodiment of the present invention, the intelligent flow control system comprises an angle sensor, a pressure sensor, a microcontroller processor, a touch screen, a proportional pressure reducing valve, a three-position four-way directional valve, a single-acting piston cylinder, and a swashplate variable displacement head. The microcontroller processor is fixedly mounted on the top of the intermediate pump body, and the microcontroller processor integrates a touch screen. A piston channel is opened at the top of the rear pump body, and an angle sensor and a piston rod are installed inside the piston channel. The lower end of the piston rod is connected to a shaft pin, which is installed in the middle of the swashplate variable displacement head. The upper end of the piston rod passes through the rear pump body and is connected to a single-acting piston cylinder via a flange. The inlet of the single-acting piston cylinder is connected to the outlet of the pressure sensor, and the inlet of the pressure sensor is connected to the A port of the three-position four-way directional valve. The P2 inlet of the three-position four-way directional valve is connected to the proportional pressure reducing valve... The outlet of the pressure reducing valve is connected, and the inlet of the proportional pressure reducing valve is connected to an external air source. The left electromagnet is de-energized, and the right electromagnet is energized. The three-position four-way directional valve operates in the right position. The A interface is connected to the P2 air inlet. The required flow rate value is set on the touch screen. The pressure sensor automatically monitors the pressure and feeds it back to the microcontroller processor. The tilt sensor automatically monitors the tilt angle of the swashplate variable head and feeds it back to the microcontroller processor. The microcontroller processor processes the data and outputs signals according to the functional relationship between pressure, tilt angle, and flow rate. The proportional pressure reducing valve adjusts the gas pressure according to the signal. The gas pressure drives the piston rod to move. The piston rod drives the shaft pin and the swashplate variable head to rotate, adjusting the tilt angle of the swashplate variable head, further adjusting the pump flow rate, realizing intelligent flow control, and displaying the flow rate value on the touch screen.

[0011] In a preferred embodiment of the present invention, the flow control circuit is connected from the pump outlet to the inlet of a three-way connector. One outlet of the three-way connector is connected to the p1 inlet of a three-position four-way directional valve. The p2 inlet of the three-position four-way directional valve is connected to the outlet of a proportional pressure reducing valve. The inlet of the proportional pressure reducing valve is connected to an external control source. The T port of the three-position four-way directional valve is connected to an oil tank. The A port of the three-position four-way directional valve is connected to the inlet of a pressure sensor. The outlet of the pressure sensor is connected to the inlet of a single-acting piston cylinder. The other outlet of the three-way connector is connected to the hydraulic system.

[0012] As a preferred embodiment of the present invention, a three-position four-way directional valve is used to realize the switching connection of multiple flow control modes. The three-position four-way directional valve mainly consists of a valve body, a valve core, a return spring, etc. Electromagnets are installed at both ends of the three-position four-way directional valve. The A port of the three-position four-way directional valve is the oil (gas) outlet, the P1 port is the oil inlet, the P2 port is the air inlet, and the T port is the oil return port (exhaust port). When the three-position four-way directional valve is in the left position, the A port is connected to the P1 oil inlet, the P2 air inlet is closed, and the T port is closed. When the three-position four-way directional valve is in the middle position, the A port is connected to the T port, the P1 oil inlet is closed, and the P2 air inlet is closed. When the three-position four-way directional valve is in the right position, the A port is connected to the P2 air inlet, the P1 air inlet is closed, and the T port is closed.

[0013] As a preferred technical solution of the present invention, a three-position four-way directional valve is used to realize the switching connection of multiple flow control modes. When the three-position four-way directional valve is in the left position, it realizes the hydraulic variable pump control mode, that is, the external feedback pressure limiting variable axial piston pump control mode. When the three-position four-way directional valve is in the middle position, it realizes the fixed displacement pump control mode. When the three-position four-way directional valve is in the right position, it realizes the pneumatic variable pump control mode, and at the same time realizes the intelligent flow control mode.

[0014] As a preferred technical solution of the present invention, a hydraulic variable pump control mode is implemented, namely an external feedback pressure-limiting variable axial piston pump control mode. The left electromagnet is energized, the right electromagnet is de-energized, the three-position four-way directional valve operates in the left position, the A port is connected to the P1 oil inlet, and the inlet of the single-acting piston cylinder is connected to the pump outlet through the left position of the three-position four-way directional valve. When the pump outlet pressure is high, the oil pressure exerts an upward force on the piston rod, which is greater than the downward elastic force generated by the pressure regulating spring. The piston rod moves upward, causing the shaft pin and swashplate variable head to rotate clockwise. The tilt angle of the swashplate variable head decreases, thus increasing the pump's displacement and flow rate. The flow rate decreases; when the pump's outlet pressure is low, the oil pressure exerts an upward force on the piston rod, which is less than the downward elastic force generated by the pressure regulating spring. The piston rod moves downward, causing the shaft pin and swashplate variable head to rotate counterclockwise. The tilt angle of the swashplate variable head increases, increasing the pump's displacement and flow rate. The swashplate variable head tilt angle is automatically adjusted based on the pump's outlet pressure to automatically regulate the pump's displacement, achieving low pressure and high flow rate, and high pressure and low flow rate. Rotating the pressure regulating screw adjusts the compression of the pressure regulating spring, which can adjust the pump's maximum working pressure, realizing the hydraulic variable pump control mode, i.e., the external feedback pressure-limiting variable axial piston pump control mode.

[0015] As a preferred technical solution of the present invention, a fixed displacement pump control mode is achieved. The left electromagnet is de-energized, the right electromagnet is de-energized, the three-position four-way directional valve is in the neutral position, the A port and the T port are connected, and the oil in the single-acting piston cylinder flows back to the oil tank through the neutral position of the three-position four-way directional valve. The pressure regulating spring at the rodless end generates a downward spring force to push the piston rod downward. The piston rod drives the shaft pin and the swashplate variable displacement head to rotate counterclockwise. The tilt angle of the swashplate variable displacement head increases, and the pump's displacement and flow rate increase. When the piston rod moves to the lowest end, the tilt angle of the swashplate variable displacement head reaches its maximum, and the pump's displacement and flow rate are at their maximum values, thus achieving the fixed displacement pump control mode.

[0016] As a preferred technical solution of the present invention, a pneumatic variable pump control mode is achieved. The left electromagnet is de-energized, the right electromagnet is energized, the three-position four-way directional valve operates in the right position, the A interface is connected to the P2 air inlet, and the inlet of the single-acting piston cylinder and the pressure sensor are connected to the proportional pressure reducing valve and the external control air source through the right position of the three-position four-way directional valve. When the external control gas pressure is high, the gas pressure generates an upward force on the piston rod, which is greater than the downward elastic force generated by the pressure regulating spring. The piston rod moves upward, and the piston rod drives the shaft pin and the swashplate variable head to rotate clockwise. The tilt angle of the swashplate variable head decreases, and the pump's displacement and flow rate decrease. When the external control gas pressure is low, the gas pressure generates an upward force on the piston rod, which is less than the downward elastic force generated by the pressure regulating spring. The piston rod moves downward, and the piston rod drives the shaft pin and the swashplate variable head to rotate counterclockwise. The tilt angle of the swashplate variable head increases, and the pump's displacement and flow rate increase, thus achieving the pneumatic variable pump control mode.

[0017] As a preferred technical solution of the present invention, an intelligent flow control mode is achieved. The left electromagnet is de-energized, the right electromagnet is energized, the three-position four-way directional valve operates in the right position, the A interface is connected to the P2 air inlet, the inlet of the single-acting piston cylinder and the pressure sensor are connected to the proportional pressure reducing valve and the external control air source through the right position of the three-position four-way directional valve. The required flow value is set on the touch screen. The pressure sensor automatically monitors the gas pressure and feeds it back to the microcontroller processor. The tilt sensor automatically monitors the tilt angle of the return plate and feeds it back to the microcontroller processor. The microcontroller processor processes the data and outputs signals according to the functional relationship between pressure, tilt angle and flow rate. The proportional pressure reducing valve adjusts the external control gas pressure according to the signal. The gas pressure drives the piston rod to move. The piston rod drives the shaft pin and the swashplate variable head to rotate, adjusting the tilt angle of the swashplate variable head, further adjusting the pump flow rate, realizing the intelligent flow control mode, and displaying the flow value on the touch screen.

[0018] As a preferred technical solution of the present invention, the switching connection of a three-position four-way reversing valve enables multiple flow control modes such as intelligent control, pneumatic variable flow, hydraulic variable flow, pressure-limiting variable flow, and quantitative pump, thereby improving the level of high-end, intelligent, and green technology and solving the problems mentioned in the background technology.

[0019] As a preferred technical solution of the present invention, a closed thin-walled structure plunger is adopted, which consists of a weight reduction chamber and a closed end. The weight reduction chamber is used to reduce weight and reduce inertia and impact force during plunger movement. The closed end is used to seal the plunger end to prevent hydraulic oil from entering the weight reduction chamber and forming harmful volume. The closed thin-walled structure plunger can reduce harmful volume, improve volumetric efficiency, and improve the dynamic performance of the plunger.

[0020] As a preferred technical solution of the present invention, in order to reduce the influence of machining errors on the cylinder end face, the connection between the cylinder and the oil distribution plate adopts a floating connection structure. The structure mainly consists of a floating spring seat, a floating spring, a floating sleeve, and a floating pressure plate. The floating spring seat is installed in the plunger hole of the cylinder, a floating spring is installed at the right end of the floating spring seat, and a floating sleeve is installed at the right end of the floating spring. Under the action of spring force and the pressure of oil in the cylinder, the floating sleeve is pressed against the floating pressure plate. The floating pressure plate has an oil distribution hole and rotates with the cylinder. The pressure plate is in contact with the oil distribution plate. When rotating, the oil distribution plate floats relative to the cylinder, realizing automatic compensation, so that the surface of the oil distribution plate can automatically adapt to machining defects such as unevenness, slight tilt, and dimensional deviation of the cylinder end face.

[0021] As a preferred technical solution of the present invention, in order to prevent unilateral wear of the oil distribution plate, six d1 blind holes with a diameter of 2.3 mm are machined in the oil sealing area of ​​the oil distribution plate; two d2 through holes with a diameter of 2.5 mm are machined. When the window is rotated to gradually cover the d1 blind holes and connect the d2 through holes, the oil fills the d1 blind holes. Due to the adhesion of the oil, the volume of the oil is greater than the volume of the d1 blind holes. After the cylinder block covers the d1 blind holes, the oil is compressed. The oil pressure in the d1 blind holes is higher than the oil outlet pressure of the pump, that is, higher than the oil film pressure, forming a high-pressure oil pillow, which can prevent the occurrence of problems such as friction, wear, and jamming between the cylinder block or floating pressure plate and the oil distribution plate.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. A novel axial piston pump is provided that realizes multiple flow control modes such as intelligent control, pneumatic variable flow, hydraulic variable flow, pressure-limiting variable flow, and fixed displacement pump, which improves the level of high-end, intelligent and green technology and solves the problems mentioned in the background technology.

[0024] 2. The flow control mechanism consists of a single-acting piston cylinder, a pivot pin, and a swashplate variable head. The piston rod of the single-acting piston cylinder is connected to the pivot pin, which is installed in the middle of the swashplate variable head.

[0025] 3. The intelligent flow control system consists of an angle sensor, a pressure sensor, a microcontroller, a touch screen, a proportional pressure reducing valve, a three-position four-way directional valve, a single-acting piston cylinder, and a swashplate variable displacement head. The three-position four-way directional valve operates in the right position. The desired flow rate value is set on the touch screen. The pressure sensor automatically monitors the pressure and feeds it back to the microcontroller. The angle sensor automatically monitors the angle of the swashplate variable displacement head and feeds it back to the microcontroller. The microcontroller processes the data and outputs signals according to the functional relationship between pressure, angle, and flow rate. The proportional pressure reducing valve adjusts the pressure according to the signal. The pressure drives the piston rod to move, which in turn drives the shaft pin and the swashplate variable displacement head to rotate, adjusting the angle of the swashplate variable displacement head and further adjusting the pump flow rate, thus achieving intelligent flow control. The flow rate value is then displayed on the touch screen.

[0026] 4. The three-position four-way directional valve is used to switch between multiple flow control modes. When the three-position four-way directional valve is in the left position, it realizes the hydraulic variable pump control mode (external feedback pressure limiting variable axial piston pump control mode). When the three-position four-way directional valve is in the middle position, it realizes the fixed displacement pump control mode. When the three-position four-way directional valve is in the right position, it realizes the pneumatic variable pump control mode, and at the same time realizes the intelligent flow control mode.

[0027] 5. Implement the hydraulic variable pump control mode, namely the external feedback pressure-limiting variable axial piston pump control mode. The left electromagnet is energized and the right electromagnet is de-energized. The three-position four-way directional valve is in the left position. The A port of the three-position four-way directional valve is connected to the oil inlet of p1. The inlet of the single-acting piston cylinder is connected to the oil outlet of the pump through the left position of the three-position four-way directional valve. When the oil outlet pressure of the pump is high, the pressure generates an upward force on the piston rod, which is greater than the downward elastic force generated by the pressure regulating spring. The piston rod moves upward, driving the shaft pin and the swashplate variable head to rotate clockwise. The tilt angle of the swashplate variable head decreases, and the pump's displacement and flow rate decrease. When the pump's outlet pressure is low, the oil pressure exerts an upward force on the piston rod, which is less than the downward elastic force generated by the pressure regulating spring. The piston rod moves downward, causing the shaft pin and swashplate variable displacement head to rotate counterclockwise. The swashplate variable displacement head tilt angle increases, increasing the pump's displacement and flow rate. The swashplate variable displacement head tilt angle is automatically adjusted based on the pump's outlet pressure, automatically regulating the pump's displacement to achieve low pressure, high flow rate, and high pressure, low flow rate. Rotating the pressure regulating screw adjusts the compression of the pressure regulating spring, which can adjust the pump's maximum working pressure, realizing the hydraulic variable displacement pump control mode, namely the external feedback pressure-limiting variable axial piston pump control mode.

[0028] 6. To achieve the pneumatic variable pump control mode, the left electromagnet is de-energized, the right electromagnet is energized, the three-position four-way directional valve operates in the right position, the A port is connected to the P2 air inlet, and the inlet of the single-acting piston cylinder and the pressure sensor are connected to the proportional pressure reducing valve and the external control air source through the right position of the three-position four-way directional valve. When the external control gas pressure is high, the gas pressure exerts an upward force on the piston rod, which is greater than the downward elastic force exerted by the pressure regulating spring. The piston rod moves upward, driving the shaft pin and the swashplate variable head to rotate clockwise, reducing the swashplate variable head tilt angle, and decreasing the pump's displacement and flow rate. When the external control gas pressure is low, the gas pressure exerts an upward force on the piston rod, which is less than the downward elastic force exerted by the pressure regulating spring. The piston rod moves downward, driving the shaft pin and the swashplate variable head to rotate counterclockwise, increasing the swashplate variable head tilt angle, and increasing the pump's displacement and flow rate, thus achieving the pneumatic variable pump control mode.

[0029] 7. To achieve intelligent flow control mode, the left electromagnet is de-energized, the right electromagnet is energized, the three-position four-way directional valve operates in the right position, the A interface is connected to the P2 air inlet, the inlet of the single-acting piston cylinder and the pressure sensor are connected to the proportional pressure reducing valve and the external control air source through the right position of the three-position four-way directional valve. The required flow value is set on the touch screen. The pressure sensor automatically monitors the gas pressure and feeds it back to the microcontroller processor. The tilt sensor automatically monitors the tilt angle of the swashplate variable head and feeds it back to the microcontroller processor. The microcontroller processor processes the data and outputs signals according to the functional relationship between pressure, tilt angle and flow rate. The proportional pressure reducing valve adjusts the external control gas pressure according to the signal. The gas pressure drives the piston rod to move, and the piston rod drives the shaft pin and the swashplate variable head to rotate, adjusting the tilt angle of the swashplate variable head, further adjusting the pump flow rate, realizing the intelligent flow control mode, and displaying the flow value on the touch screen. Attached Figure Description

[0030] Figure 1 This is a schematic cross-sectional view of the present invention. Figure 1 ; Figure 2 This is a schematic cross-sectional view of the present invention. Figure 2 ; Figure 3 This is a schematic diagram illustrating the flow control principle of the present invention; Figure 4 This is a schematic diagram of the functional structure of the three-position four-way directional valve of the present invention; Figure 5 This is a schematic diagram of the closed thin-walled plunger structure of the present invention; Figure 6 This is a schematic diagram of the floating connection structure of the present invention; Figure 7 This is a schematic diagram of the structure of the d1 blind hole and d2 through hole of the present invention.

[0031] In the diagram: 1. Front pump body; 2. Middle pump body; 3. Rear pump body; 4. Rear end cover; 5. Front end cover; 6. Swashplate variable displacement head; 7. Shaft pin; 8. Return plate; 9. Slipper head; 10. Piston; 11. Cylinder block; 12. Spring component; 13. Ball joint; 14. Oil distribution plate; 15. Oil outlet; 16. Output shaft; 17. Piston passage; 18. Piston rod; 19. Tilt sensor; 20. Sealing sleeve; 21. Sealing sleeve; 22. Flange component; 23. Single-acting piston cylinder; 24. Microcontroller processor; 25. Touch screen; 26. T-joint; 27. Ball bearing. Components; 28. Proportional pressure reducing valve; 29. ​​Three-position four-way directional valve; 30. Pressure sensor; 31. Pressure regulating spring; 32. Pressure regulating spring seat; 33. Pressure regulating screw; 34. A interface; 35. T interface; 36. P1 oil inlet; 37. P2 air inlet; 38. Left electromagnet; 39. Right electromagnet; 40. Inlet; 41. D1 blind hole; 42. D2 through hole; 43. Floating pressure plate; 44. Floating sleeve; 45. Floating spring; 46. Floating spring seat; 47. Rod chamber; 48. Rodless chamber; 49. Weight reduction chamber; 50. Closed end; 51. External air source. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figure 1-7This invention provides a technical solution for a novel axial piston pump and its flow control structure:

[0034] The system includes a front pump body (1), a middle pump body (2), a rear pump body (3), and a three-position four-way reversing valve (29). The two ends of the middle pump body (2) are respectively assembled and connected to the front pump body (1) and the rear pump body (3). A ball bearing assembly (27) is fixedly installed at one end of the inner cavity of the front pump body (1). An output shaft (16) is assembled and connected inside the ball bearing assembly (27). A microcontroller processor (24) is fixedly installed at the top of the middle pump body (2). A touch screen (25) is integrated at the top of the microcontroller processor. An oil distribution plate (14) is assembled and connected inside the middle pump body (2). A d1 blind hole (41) and a d2 through hole (42) are machined in the oil sealing area of ​​the oil distribution plate (14). One end of the oil distribution plate (14) is floatingly connected to the cylinder body (11). 1) The cylinder (11) is installed in the chamber of the intermediate pump body (2) by bearings. The piston holes inside the cylinder (11) are equipped with pistons (10). The pistons (10) are closed thin-walled pistons. One end of the output shaft (16) is fixedly connected to a spring (12). One end of the spring (12) is connected to a ball joint (13). One end of the ball joint (13) is connected to a return plate (8). Multiple slipper heads (9) are installed on the surface of the return plate (8). The slipper heads (9) are correspondingly connected to the pistons (10). One end of each slipper head (9) is connected to a swashplate variable head (6). The bottom end of the front pump body (1) is provided with an oil outlet (15). The oil outlet (15) is connected to the inlet of the three-way pipe joint (26). One end of the three-way pipe joint (26) is connected to the oil outlet. The port is connected to the p1 oil inlet (36) of the three-position four-way directional valve (29), the p2 air inlet (37) of the three-position four-way directional valve (29) is connected to the outlet of the proportional pressure reducing valve (28), the inlet of the proportional pressure reducing valve (28) is connected to the external control air source (51), the T port (35) of the three-position four-way directional valve (29) is connected to the oil tank, the A port (34) of the three-position four-way directional valve (29) is connected to the inlet of the pressure sensor (30), the outlet of the pressure sensor (30) is connected to the inlet (40) of the single-acting piston cylinder (23), a piston channel (17) is opened at the top of the rear pump body (3), an tilt sensor (19) and a piston rod (18) are installed inside the piston channel (17), and the upper end of the piston rod (18) A single-acting piston cylinder (23) is connected through the rear pump body (3) and flange (22). The rod chamber (47) of the single-acting piston cylinder (23) is equipped with an inlet (40). The top of the rodless chamber (48) of the single-acting piston cylinder (23) is connected to a pressure adjusting screw (33) by a thread. A pressure adjusting spring seat (32) is installed at the lower end of the pressure adjusting screw (33). An adjusting spring (31) is installed at the lower end of the pressure adjusting spring seat. A piston rod (18) is installed at the lower end of the pressure adjusting spring. A shaft pin (7) is connected to the lower end of the piston rod (18). The shaft pin (7) is installed in the middle of the swashplate variable head (6). A sealing sleeve (21) and a sealing sleeve (20) are fixedly installed at the top of the piston channel (17). Both are movably connected to the piston rod (18).A front cover (5) is fitted to one end of the front pump body (1), and a rear cover (4) is fitted to one end of the rear pump body (3).

[0035] The single-acting piston cylinder (23) is a variable drive mechanism. Its structure is mainly composed of a pressure adjusting screw (33), a pressure adjusting spring seat (32), a pressure adjusting spring (31), and a piston rod (18). The top of the rodless chamber (48) of the single-acting piston cylinder (23) is connected to the pressure adjusting screw (33) by a thread. The pressure adjusting spring seat (32) is installed at the lower end of the pressure adjusting screw (33). The pressure adjusting spring (31) is installed at the lower end of the pressure adjusting spring seat (32). The piston rod (18) is installed at the lower end of the pressure adjusting spring (3). The rod chamber (47) of the single-acting piston cylinder (23) is equipped with an inlet (40).

[0036] The flow control mechanism consists of a single-acting piston cylinder (23), a shaft pin (7), and a swashplate variable head (6). The piston rod (18) of the single-acting piston cylinder (23) is connected to the shaft pin (7), and the shaft pin (7) is installed in the middle of the swashplate variable head (6).

[0037] The intelligent flow control system mainly consists of an angle sensor (19), a pressure sensor (30), a microcontroller (24), a touch screen (25), a proportional pressure reducing valve (28), a three-position four-way directional valve (29), a single-acting piston cylinder (23), and a swashplate variable head (6). The microcontroller (24) is fixedly installed at the top of the intermediate pump body (2), and the touch screen (25) is integrated into the microcontroller (24). An angle sensor (19) and a piston rod (18) are installed inside the piston channel (17). The lower end of the piston rod (18) is connected to a shaft pin (7), which is installed in the middle of the swashplate variable head (6). The inlet (40) of the single-acting piston cylinder (23) is connected to the outlet of the pressure sensor (30). The inlet of the pressure sensor (30) is connected to the A port (34) of the three-position four-way directional valve (29). The p2 inlet (37) of the three-position four-way directional valve (29) is connected to the outlet of the proportional pressure reducing valve (28). The proportional pressure reducing valve (28) is connected to the external control air source (51). The left electromagnet (38) is de-energized and the right electromagnet is energized. The three-position four-way reversing valve (29) is in the right position. The A interface (34) is connected to the p2 air inlet (37). The required flow rate value is set on the touch screen (25). The pressure sensor (30) automatically monitors the pressure and feeds it back to the microcontroller processor (24). The tilt sensor (19) automatically monitors the tilt angle of the swashplate variable head (6) and feeds it back to the microcontroller processor (24). The microcontroller processor (24) processes the data and outputs the signal according to the functional relationship between pressure, tilt angle and flow rate. The proportional pressure reducing valve (28) adjusts the gas pressure according to the signal. The gas pressure drives the piston rod (18) to move. The piston rod (18) drives the shaft pin (7) and the swashplate variable head (6) to rotate. The tilt angle of the swashplate variable head (6) is adjusted to further adjust the flow rate of the pump, realize intelligent flow control, and display the flow rate value on the touch screen (25).

[0038] The flow control loop is connected from the pump outlet (15) to the inlet of the three-way pipe joint (26). One outlet of the three-way pipe joint (26) is connected to the p1 inlet (36) of the three-position four-way directional valve (29). The P2 air inlet (37) of the three-position four-way directional valve (29) is connected to the outlet of the proportional pressure reducing valve (28). The inlet of the proportional pressure reducing valve (28) is connected to the external control air source (51). The T port (35) of the three-position four-way directional valve (29) is connected to the oil tank. The A port (34) of the three-position four-way directional valve (29) is connected to the inlet of the pressure sensor (30). The outlet of the pressure sensor (30) is connected to the inlet (40) of the single-acting piston cylinder (23). The other outlet of the three-way pipe joint (26) is connected to the hydraulic system.

[0039] The structure of the three-position four-way directional valve (29) mainly consists of a valve body, valve core, return spring, electromagnet, etc. Electromagnets are installed at both ends of the three-position four-way directional valve (29). The A port (34) of the three-position four-way directional valve (29) is the oil (gas) outlet, the P1 port (36) is the oil inlet, the P2 port (37) is the air inlet, and the T port (35) is the oil return port (exhaust port). When working in the left position, the A port (34) is connected to the P1 oil inlet (36), the P2 air inlet (37) is closed, and the T port (35) is closed. When working in the middle position, the A port (34) is connected to the T port (35), the P1 oil inlet (36) is closed, and the P2 air inlet (37) is closed. When working in the right position, the A port (34) is connected to the P2 air inlet (37), the P1 oil inlet (36) is closed, and the T port (35) is closed.

[0040] The three-position four-way directional valve is used to realize the switching connection of multiple flow control modes. When the three-position four-way directional valve (29) is in the left position, it realizes the hydraulic variable control mode (external feedback pressure limiting variable axial piston pump control mode). When the three-position four-way directional valve (29) is in the middle position, it realizes the quantitative pump control mode. When the three-position four-way directional valve (29) is in the right position, it realizes the pneumatic variable control mode and at the same time realizes the intelligent flow control mode.

[0041] To achieve the hydraulic variable pump control mode, namely the external feedback pressure-limiting variable axial piston pump control mode, the left electromagnet (47) is energized, the right electromagnet (48) is de-energized, the three-position four-way directional valve (29) is in the left position, the A port is connected to the p1 oil inlet, and the inlet (40) of the single-acting piston cylinder (23) is connected to the pump outlet (15) through the left position of the three-position four-way directional valve (29). When the pressure at the pump outlet (15) is high, the pressure exerts an upward force on the piston rod (18), which is greater than the downward elastic force exerted by the pressure regulating spring (31). When this force is greater, the piston rod (18) moves upward, causing the shaft pin (7) and the swashplate variable head (6) to rotate clockwise. The tilt angle of the swashplate variable head (6) decreases, and the pump's displacement and flow rate increase. When the pressure at the pump outlet (15) is low, the pressure exerts an upward force on the piston rod (18), which is less than the downward elastic force exerted by the pressure regulating spring (31). The piston rod (18) moves downward, causing the shaft pin (7) and the swashplate variable head (6) to rotate counterclockwise. The tilt angle of the swashplate variable head (6) increases, and the pump's displacement and flow rate increase. The tilt angle of the swashplate variable head (6) is automatically adjusted by the pressure at the pump outlet (15), and the pump's displacement is automatically adjusted to achieve low pressure and high flow rate, and high pressure and low flow rate. By rotating the pressure regulating screw (33) and adjusting the compression of the pressure regulating spring (31), the maximum working pressure of the pump can be adjusted, realizing the hydraulic variable pump control mode, namely the external feedback pressure limiting variable axial piston pump control mode.

[0042] To achieve the fixed displacement pump control mode, the left electromagnet (47) is de-energized, the right electromagnet (48) is de-energized, the three-position four-way directional valve (29) is in the neutral position, the A port (34) and the T port (35) are connected, the hydraulic oil in the rod chamber (47) of the single-acting piston cylinder (23) flows back to the oil tank through the neutral position of the three-position four-way directional valve (29), the pressure regulating spring (31) generates a downward elastic force, the piston rod (18) moves downward, driving the shaft pin (7) and the swashplate variable head (6) to rotate counterclockwise, the tilt angle of the swashplate variable head (6) increases, the pump's displacement and flow rate increase, when the piston rod (18) moves to the lowest end, the tilt angle of the swashplate variable head (6) is the maximum, the pump's displacement and flow rate are at the maximum value, thus achieving the fixed displacement pump control mode.

[0043] To achieve the pneumatic variable pump control mode, the left electromagnet (47) is de-energized, the right electromagnet (48) is energized, the right position of the three-position four-way directional valve (29) is activated, the A port (34) is connected to the p2 inlet (37), the inlet (40) of the single-acting piston cylinder (23) and the pressure sensor (30) are connected to the proportional pressure reducing valve (28) and the external air source (51) through the right position of the three-position four-way directional valve (29). When the gas pressure is high, the gas pressure generates an upward force on the piston rod (18), which is greater than the force generated by the pressure regulating spring (31). The piston rod (18) moves upward due to the downward elastic force, causing the shaft pin (7) and the swashplate variable head (6) to rotate clockwise. The tilt angle of the swashplate variable head (6) decreases, and the pump's displacement and flow rate decrease. When the gas pressure is low, the gas pressure exerts an upward force on the piston rod (18), which is less than the downward elastic force exerted by the pressure regulating spring (31). The piston rod (18) moves downward, causing the shaft pin (7) and the swashplate variable head (6) to rotate counterclockwise. The tilt angle of the swashplate variable head (6) increases, and the pump's displacement and flow rate increase, thus realizing the pneumatic variable pump control mode.

[0044] To achieve intelligent flow control mode, the left electromagnet (47) is de-energized, the right electromagnet (48) is energized, the right position of the three-position four-way directional valve (29) is activated, the A interface (34) is connected to the p2 air inlet (37), the inlet (40) of the single-acting piston cylinder (23) and the pressure sensor (30) are connected to the proportional pressure reducing valve (28) and the external air source (51) through the right position of the three-position four-way directional valve (29), the required flow rate value is set on the touch screen (25), the pressure sensor (30) automatically monitors the gas pressure and feeds it back to the microcontroller processor (24), and the tilt angle is adjusted. The sensor (19) automatically monitors the tilt angle of the swashplate variable head (6) and feeds it back to the microcontroller processor (24). The microcontroller processor (24) processes the data and outputs the signal according to the functional relationship between pressure, tilt angle and flow rate. The proportional pressure reducing valve (28) adjusts the external control gas pressure according to the signal. The gas pressure drives the piston rod (18) to move. The piston rod (18) drives the shaft pin (7) and the swashplate variable head (6) to rotate, adjusting the tilt angle of the swashplate variable head (6) and further adjusting the flow rate of the pump. This achieves the intelligent flow control mode and displays the flow rate value on the touch screen (25).

[0045] The three-position four-way reversing valve (29) is used to realize the switching connection of multiple flow control modes, realize multiple flow control modes such as intelligent control, pneumatic variable, hydraulic variable, pressure limiting variable, and quantitative pump, improve the level of high-end, intelligent and green, and solve the problems raised in the background technology.

[0046] The plunger (10) adopts a closed thin-walled structure plunger, which consists of a weight reduction chamber (49) and a closed end (50). The weight reduction chamber (49) is used to reduce weight and reduce inertia and impact force during plunger movement. The closed end (50) is used to close the plunger end to prevent hydraulic oil from entering the weight reduction chamber (49) and forming harmful volume. The closed thin-walled structure plunger (10) can reduce harmful volume, improve volumetric efficiency, and improve the dynamic performance of the plunger (10).

[0047] To reduce the impact of machining errors on the end face of the cylinder block (11), a floating connection is adopted between the cylinder block (11) and the oil distribution plate (14). A floating spring seat (46) is installed in the plunger hole of the cylinder block (11), a floating spring (45) is installed on the right end of the floating spring seat (46), and a floating sleeve (44) is installed on the right end of the floating spring. Under the action of spring force and oil pressure in the plunger hole of the cylinder block (11), the floating sleeve (44) is pressed on the floating pressure plate (43). The floating pressure plate (43) has an oil distribution hole and rotates with the cylinder block (11). The floating pressure plate (43) is in contact with the oil distribution plate (14). When rotating, the oil distribution plate (14) floats relative to the cylinder block (11) to achieve automatic compensation, so that the surface of the oil distribution plate (14) can automatically adapt to machining defects such as unevenness, slight tilt, and dimensional deviation of the end face of the cylinder block (11).

[0048] To prevent unilateral wear of the oil distribution plate (14), six d1 blind holes (41) with a diameter of 2.3 mm are machined in the oil sealing area of ​​the oil distribution plate (14); two d2 through holes (42) with a diameter of 2.5 mm are machined. When the window is rotated to gradually cover the d1 blind holes (41) and connect the d2 holes (42), the oil fills the d1 blind holes (41). Due to the adhesion of the oil, the volume of the oil is greater than the volume of the d1 blind holes (41). After the cylinder block (11) covers the d1 blind holes (41), the oil is compressed. The oil pressure in the d1 blind holes (41) is higher than the pressure of the pump outlet (15), which is higher than the oil film pressure, forming a high-pressure oil pillow, which can prevent the occurrence of friction, wear, jamming and other problems between the cylinder block (11) or floating pressure plate (43) and the oil distribution plate (14).

[0049] In the description of this invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the purpose of facilitating the description of this invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0050] In this invention, unless otherwise explicitly specified and limited, for example, it can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements or an interaction between two elements. Unless otherwise explicitly limited, those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel axial piston pump, comprising a front pump body (1), an intermediate pump body (2), a rear pump body (3), and a three-position four-way directional valve (29), characterized in that: The A port (34) of the three-position four-way reversing valve (29) is an oil outlet or an air outlet, and the T port (35) is an oil return port or an exhaust port. The two ends of the intermediate pump body (2) are respectively assembled and connected to the front pump body (1) and the rear pump body (3). The bottom end of the front pump body (1) is provided with an oil outlet (15). The oil outlet (15) is connected to the inlet of the three-way pipe joint (26). One outlet of the three-way pipe joint (26) is connected to the p1 oil inlet (36) of the three-position four-way reversing valve (29). The p2 air inlet (37) of the three-position four-way reversing valve (29) is connected to the outlet of the proportional pressure reducing valve (28). The inlet of the proportional pressure reducing valve (28) is connected to the external control air source (51). The T port (35) of the directional control valve (29) is connected to the oil tank. The A port (34) of the three-position four-way directional control valve (29) is connected to the inlet of the pressure sensor (30). The outlet of the pressure sensor (30) is connected to the inlet (40) of the single-acting piston cylinder (23). A microcontroller processor (24) is fixedly installed on the top of the intermediate pump body (2). A touch screen (25) is integrated on the top of the microcontroller processor (24). An oil distribution plate (14) is installed inside the intermediate pump body (2). A d1 blind hole (41) and a d2 through hole (42) are machined in the oil sealing area of ​​the oil distribution plate (14). One end of the oil distribution plate (14) is floatingly connected to the cylinder body (11). The cylinder body (11) is mounted on the cylinder body (11) by bearings. In the chamber of the intermediate pump body (2), plungers (10) are installed in the plunger holes inside the cylinder body (11). The plungers (10) are closed thin-walled plungers. One end of the output shaft (16) is fixedly connected to a spring (12). One end of the spring (12) is connected to a ball joint (13). One end of the ball joint (13) is connected to a return plate (8). Multiple slipper heads (9) are installed on the surface of the return plate (8). The slipper heads (9) are correspondingly connected to the plungers (10). One end of each slipper head (9) is connected to a swashplate variable head (6). A piston channel (17) is opened at the top of the rear pump body (3). An angle sensor is installed inside the piston channel (17). The device (19) and piston rod (18) are connected. The upper end of the piston rod (18) passes through the rear pump body (3) and is connected to a single-acting piston cylinder (23) through a flange (22). The rod chamber (47) of the single-acting piston cylinder (23) is equipped with an inlet (40). The top of the rodless chamber (48) of the single-acting piston cylinder (23) is connected to a pressure adjusting screw (33) by a thread. A pressure adjusting spring seat (32) is installed at the lower end of the pressure adjusting screw (33). A pressure adjusting spring (31) is installed at the lower end of the pressure adjusting spring seat. The piston rod (18) is installed at the lower end of the pressure adjusting spring (31). A shaft pin (7) is connected to the lower end of the piston rod (18). The shaft pin (7) is installed in the middle of the swashplate variable head (6).

2. The novel axial piston pump according to claim 1, characterized in that: The intelligent flow control system consists of an inclination sensor (19), a pressure sensor (30), a microcontroller processor (24), a touch screen (25), a proportional pressure reducing valve (28), a three-position four-way directional valve (29), a single-acting piston cylinder (23), and a swashplate variable head (6).

3. A novel axial piston pump according to claim 1, characterized in that: The three-position four-way directional valve (29) is used to switch between intelligent control, pneumatic variable, hydraulic variable, and fixed displacement pump control modes. When the three-position four-way directional valve (29) is in the left position, the A port (34) is connected to the p1 oil inlet (36), the p2 air inlet (37) is closed, and the T port (35) is closed. When the three-position four-way directional valve (29) is in the middle position, the A port (34) is connected to the T port (35), the p1 oil inlet (36) is closed, and the p2 air inlet (37) is closed. When the valve is in the right position, the A port (34) is connected to the p2 air inlet (37), the p1 oil inlet (36) is closed, and the T port (35) is closed. When the three-position four-way directional valve (29) is in the left position, it realizes the hydraulic variable control mode, that is, the external feedback pressure limiting variable axial piston pump control mode. When the three-position four-way directional valve (29) is in the middle position, it realizes the quantitative pump control mode. When the three-position four-way directional valve (29) is in the right position, it realizes the pneumatic variable pump control mode, and at the same time realizes the intelligent flow control mode.

4. A novel axial piston pump according to claim 1, characterized in that: To achieve the hydraulic variable control mode, namely the external feedback pressure-limiting variable axial piston pump control mode, the left electromagnet (38) is energized, the right electromagnet (39) is de-energized, the three-position four-way directional valve (29) is in the left position, the A port (34) is connected to the p1 oil inlet (36), and the inlet (40) of the single-acting piston cylinder (23) is connected to the pump outlet (15) through the left position of the three-position four-way directional valve (29). When the pressure at the outlet (15) is high, the oil pressure generates an upward force on the piston rod (18), which is greater than the downward elastic force generated by the pressure regulating spring (31). The piston rod (18) moves upward, driving the shaft pin (7) and the swashplate variable head (6) to rotate clockwise. The tilt angle of the swashplate variable head (6) decreases, and the pump's displacement and flow rate increase. When the pressure at the oil outlet (15) is low, the oil pressure exerts an upward force on the piston rod (18), which is less than the downward elastic force exerted by the pressure regulating spring (31). The piston rod (18) moves downward, causing the shaft pin (7) and the swashplate variable head (6) to rotate counterclockwise. The tilt angle of the swashplate variable head (6) increases, and the pump's displacement and flow rate increase. The tilt angle of the swashplate variable head (6) is automatically adjusted by the pressure at the oil outlet (15), and the pump's displacement is automatically adjusted to achieve low pressure and high flow rate, and high pressure and low flow rate. By rotating the pressure regulating screw (33) and adjusting the compression of the pressure regulating spring (31), the maximum working pressure of the pump can be adjusted, realizing the hydraulic variable pump control mode, namely the external feedback pressure limiting variable axial piston pump control mode.

5. A novel axial piston pump according to claim 1, characterized in that: To achieve the quantitative pump control mode, the left electromagnet (38) is de-energized, the right electromagnet (39) is de-energized, the three-position four-way directional valve (29) is in the middle position, the A interface (34) and the T interface (35) are connected, the hydraulic oil in the rod chamber (47) of the single-acting piston cylinder (23) flows back to the oil tank through the middle position of the three-position four-way directional valve (29), the pressure regulating spring (31) generates a downward elastic force, the piston rod (18) moves downward, driving the shaft pin (7) and the swashplate variable head (6) to rotate counterclockwise, the tilt angle of the swashplate variable head (6) increases, the pump's displacement and flow rate increase, when the piston rod (18) moves to the lowest end, the tilt angle of the swashplate variable head (6) is the largest, the pump's displacement and flow rate are at the maximum value, thus achieving the quantitative pump control mode.

6. A novel axial piston pump according to claim 1, characterized in that: To achieve the pneumatic variable pump control mode, the left electromagnet (38) is de-energized, the right electromagnet (39) is energized, the three-position four-way directional valve (29) operates in the right position, the A port (34) is connected to the p2 air inlet (37), the inlet (40) of the single-acting piston cylinder (23) and the pressure sensor (30) are connected to the proportional pressure reducing valve (28) and the external control air source (51) through the right position of the three-position four-way directional valve (29). When the gas pressure is high, the gas pressure generates an upward force on the piston rod (18), which is greater than the downward elastic force generated by the pressure regulating spring (31). When the piston rod (18) moves upward, it causes the shaft pin (7) and the swashplate variable head (6) to rotate clockwise. The tilt angle of the swashplate variable head (6) decreases, and the pump's displacement and flow rate decrease. When the gas pressure is low, the gas pressure exerts an upward force on the piston rod (18), which is less than the downward elastic force exerted by the pressure regulating spring (31). The piston rod (18) moves downward, causing the shaft pin (7) and the swashplate variable head (6) to rotate counterclockwise. The tilt angle of the swashplate variable head (6) increases, and the pump's displacement and flow rate increase, thus realizing the pneumatic variable pump control mode.

7. A novel axial piston pump according to claim 1, characterized in that: To achieve intelligent flow control mode, the left electromagnet (38) is de-energized, the right electromagnet (39) is energized, the three-position four-way reversing valve (29) is in the right position, the A interface (34) is connected to the p2 air inlet (37), the inlet (40) of the single-acting piston cylinder (23) and the pressure sensor (30) are connected to the proportional pressure reducing valve (28) and the external control air source (51) through the right position of the three-position four-way reversing valve (29), the required flow value is set on the touch screen (25), the pressure sensor (30) automatically monitors the gas pressure and feeds it back to the microcontroller processor (24), the tilt sensor ( 19) Automatically monitor the tilt angle of the swashplate variable head (6) and feed it back to the microcontroller processor (24). The microcontroller processor (24) processes the data and outputs the signal according to the functional relationship between pressure, tilt angle and flow rate. The proportional pressure reducing valve (28) adjusts the gas pressure according to the signal. The gas pressure drives the piston rod (18) to move. The piston rod (18) drives the shaft pin (7) and the swashplate variable head (6) to rotate, adjust the tilt angle of the swashplate variable head (6), further adjust the flow rate of the pump, realize the intelligent flow control mode, and display the flow rate value on the touch screen (25).

8. A novel axial piston pump according to claim 1, characterized in that: The plunger (10) adopts a closed thin-walled structure plunger, which consists of a weight reduction chamber (49) and a closed end (50). The weight reduction chamber (49) is used to reduce weight and reduce inertia and impact force during plunger movement. The closed end (50) is used to close the plunger end to prevent hydraulic oil from entering the weight reduction chamber (49) and forming harmful volume. The closed thin-walled structure plunger (10) can reduce harmful volume, improve volumetric efficiency, and improve the dynamic performance of the plunger (10).

9. A novel axial piston pump according to claim 1, characterized in that: To reduce the impact of machining errors on the end face of the cylinder block (11), a floating connection structure is adopted between the cylinder block (11) and the oil distribution plate (14). The structure consists of a floating spring seat, a floating spring, a floating sleeve, and a floating pressure plate. A floating spring seat (46) is installed in the plunger hole of the cylinder block (11). A floating spring (45) is installed at the right end of the floating spring seat (46). A floating sleeve (44) is installed at the right end of the floating spring (45). The spring force and the cylinder block (11) are combined to form a floating spring. Under the pressure of the oil, the floating sleeve (44) is pressed against the floating pressure plate (43). The floating pressure plate (43) has an oil distribution hole and rotates with the cylinder (11). The floating pressure plate (43) is in contact with the oil distribution plate (14). When rotating, the oil distribution plate (14) floats relative to the cylinder (11) to achieve automatic compensation, so that the surface of the oil distribution plate (14) can automatically adapt to the unevenness, slight tilt, and dimensional deviation of the cylinder (11) end face processing defects.

10. A novel axial piston pump according to claim 1, characterized in that: To prevent unilateral wear of the oil distribution plate (14), six d1 blind holes (41) with a diameter of 2.3 mm are machined in the oil sealing area of ​​the oil distribution plate (14), and two d2 through holes (42) with a diameter of 2.5 mm are machined. When the window is rotated to gradually cover the d1 blind holes (41) and connect the d2 holes (42), the oil fills the d1 blind holes (41). Due to the adhesion of the oil, the volume of the oil is greater than the volume of the d1 blind holes (41). After the cylinder body (11) covers the d1 blind holes (41), the oil is compressed. The oil pressure in the d1 blind holes (41) is higher than the pressure of the pump outlet (15), that is, higher than the oil film pressure, forming a high-pressure oil pillow, which can prevent friction, wear and jamming between the cylinder body (11) or floating pressure plate (43) and the oil distribution plate (14).

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