Load-based adaptive constant pressure variable hydraulic piston pump

Abstract

The application relates to the technical field of aircraft hydraulic systems, and discloses a self-adaptive constant-pressure variable hydraulic plunger pump based on load, which comprises a connecting part and a hydraulic plunger pump, the connecting part comprises a mounting seat, an inner shaft extending to an inner cavity is arranged at the rear end of the mounting seat, a transmission shaft is arranged in the inner sleeve at the rear end of the inner shaft and used for connecting an engine, a blade wheel shaft is connected to the front end of the inner shaft, an inlet pipe joint is sleeved on the front end of the blade wheel shaft, a rotor assembly is sleeved on the inner shaft in the mounting seat and the inner shaft drives the rotor assembly to rotate, a plunger assembly is inserted at the rear end of the rotor assembly, and a swash plate assembly is tightly arranged at the rear end of the plunger assembly. The application can realize real-time sensing of the actual pressure demand of the system load, dynamically adjust the output pressure of the pump, make the output pressure always match the current working condition, adjust the constant-pressure pressure point adaptively according to the actual load pressure demand of the system, and fundamentally solve the high energy consumption and high heating problems of the hydraulic plunger pump under non-peak working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft hydraulic systems. BACKGROUND

[0002] The aircraft hydraulic system is the "muscle and nerve" of the aircraft, and its performance is directly related to the reliability and efficiency of key functions such as flight control, landing gear retraction, and brakes. The hydraulic piston pump, as one of the power cores of the aircraft hydraulic system, has a decisive influence on the energy consumption and thermal management of the aircraft.

[0003] At present, the mainstream large aircraft widely uses swash plate type axial constant pressure variable hydraulic piston pump as the hydraulic source. The basic working principle is: when the system pressure reaches the preset set pressure, the variable mechanism of the pump automatically adjusts the swash plate angle to reduce the output flow, thereby maintaining the constant output pressure of the hydraulic piston pump. This structural design can ensure that the hydraulic piston pump can provide sufficient and stable pressure under high peak load working conditions to meet the requirements of the aircraft on the output characteristics of the power source.

[0004] However, there is a relatively significant inherent defect in the constant pressure variable characteristics of the traditional constant pressure variable hydraulic piston pump. The flight profile of the aircraft is complex, and the demand for the output flow of the hydraulic piston pump fluctuates greatly at different flight stages (such as cruising, climbing, descending, and ground operation). The constant pressure value of the hydraulic piston pump (for example, 28 MPa) must be set according to the highest pressure demand that may occur within the full flight envelope to ensure that the hydraulic piston pump can output sufficient flow of high pressure hydraulic oil under the most demanding conditions. This means that in the medium and low load conditions (such as cruising and ground sliding) that account for the vast majority of flight time, the hydraulic piston pump can be passively switched to a high pressure and low flow state by the feedback of the outlet pressure to maintain constant pressure, but the actual working pressure required by the system is much lower than the preset constant pressure value. The pump continuously outputs high pressure oil, and when these high pressure oils are reduced and adjusted through overflow valves or servo mechanisms, the huge pressure difference will cause a large amount of hydraulic energy to be converted into heat energy through throttling and overflow, resulting in serious energy loss.

[0005] The above energy loss will bring two major disadvantages: first, it increases the fuel consumption of the aircraft, resulting in a reduction in the endurance range of the aircraft; second, a large amount of useless work is converted into heat, causing the temperature of the hydraulic oil to rise, which will cause the hydraulic oil and the sealing elements to age faster, reducing the reliability of the system.

[0006] Analysis revealed that the main cause of the aforementioned technical problems is that the pressure setting of the existing constant pressure pump must meet the highest load requirements. As a result, under the dominant medium and low load conditions, the pump output pressure is much higher than the required working pressure. A large amount of high-pressure fluid is dissipated as heat after throttling, resulting in unnecessary fuel consumption and seriously affecting the aircraft's energy consumption and economy. The waste of this energy will directly lead to a faster rate of increase in hydraulic system oil temperature, which will not only accelerate the aging of hydraulic oil and seals, threatening the reliability of the hydraulic system, but also force the aircraft hydraulic system to be equipped with a larger power and volume cooling system, adding extra weight and design burden to the hydraulic system. Summary of the Invention

[0007] The purpose of this invention is to provide a load-based adaptive constant pressure variable hydraulic piston pump that can adaptively adjust the constant pressure point according to the actual load pressure requirements of the system, thereby fundamentally solving the problems of high energy consumption and high heat generation of hydraulic piston pumps under non-peak operating conditions.

[0008] To solve the above-mentioned technical problems, the present invention provides a load-based adaptive constant-pressure variable hydraulic piston pump, including a connecting part and a hydraulic piston pump. The connecting part includes a mounting base, with an inner shaft extending into the inner cavity rotatably mounted at the rear end of the mounting base. A drive shaft for connecting to an engine is installed inside the rear end of the inner shaft. The front end of the inner shaft is connected to and drives an impeller shaft. An inlet pipe joint is fitted at the front end of the impeller shaft. A rotor assembly is mounted on the inner shaft inside the mounting base, and the inner shaft drives the rotor assembly to rotate. A piston assembly is inserted at the rear end of the rotor assembly. A swashplate assembly is tightly mounted at the rear end of the piston assembly. There is a cavity between the swashplate assembly and the mounting base. A follower piston is located at the front end of the outer edge of the swashplate assembly, pressing against the swashplate assembly and installed in a follower piston sleeve. The follower piston sleeve is fixed inside the mounting base. The hydraulic plunger pump includes an electromagnetic valve, which is electrically connected to a control box. A high-pressure valve is located at the front end of the electromagnetic valve and is fitted into a high-pressure valve sleeve. An electromagnetic valve spring is fitted between the electromagnetic valve and the high-pressure valve sleeve. A spring guide rod is connected and installed at the front end of the high-pressure valve sleeve and is fitted into a pressure-adjusting screw sleeve. A pressure-adjusting spring seat is fixed inside the front end of the pressure-adjusting screw sleeve, and a pressure-adjusting spring is installed between the spring guide rod and the pressure-adjusting spring seat. There is a chamber between the front end of the electromagnetic valve and the rear end of the high-pressure valve sleeve, which is connected to the chamber between the plunger assembly and the oil distributor assembly via an outlet oil passage. The high-pressure valve sleeve is divided into three parts: front, middle, and rear. There is a gap between the middle and rear parts, which is connected to the chamber between the follower piston and the follower piston sleeve via a control chamber oil passage.

[0009] The high-pressure valve sleeve has a chamber on its front middle section side, which is connected to the cavity between the swashplate assembly and the mounting base via a return oil circuit.

[0010] The front end of the pressure regulating screw sleeve is fitted with an adjustment cover.

[0011] The bottom edge of the adjusting cover has a locking nut fitted onto the pressure adjusting screw sleeve.

[0012] The rear end face of the swashplate assembly, directly opposite the follower piston, has a housing fitted inside the guide rod sleeve, which is fixed to the inner wall of the mounting base.

[0013] A guide rod is fitted onto the housing, and a return spring assembly is fitted onto the outside of the guide rod. The two ends of the return spring assembly are fixed to the guide rod sleeve and the end of the housing, respectively.

[0014] The inner shaft drives the impeller shaft via a spline. A booster impeller assembly is mounted on the impeller shaft at the front end of the inner shaft, and the impeller shaft drives the booster impeller assembly via a spline.

[0015] The drive shaft and the inner shaft are connected by a spline.

[0016] The plunger assembly is inserted into the plunger hole of the rotor assembly, which opens towards the rear end.

[0017] The inner shaft and rotor assembly are driven by splines.

[0018] Compared with existing technologies, this invention can sense the actual pressure demand of the system load in real time and dynamically adjust the output pressure of the pump to match the current working conditions. It can effectively reduce the energy consumption of the hydraulic system, improve the efficiency of aviation fuel use, and has important economic and environmental significance. It can effectively improve the thermal management of the hydraulic system and hydraulic piston pump, and effectively delay the aging rate of hydraulic oil and seals, thereby improving the reliability and service life of the entire hydraulic system and having high reliability.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a schematic diagram of the structure of the connecting portion in at least one embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a hydraulic piston pump in at least one embodiment of the present invention;

[0023] Figure 3 yesFigure 1 , Figure 2 Schematic diagram of the control principle;

[0024] Figure 4 This is a PQ curve of an adaptive constant pressure variable hydraulic piston pump with an output flow rate of 30 L / min at constant pressure levels of 8 MPa, 14 MPa, 21 MPa, and 28 MPa, respectively.

[0025] Figure 5 yes Figure 1 A schematic diagram of the structure with the oil passage removed from the connecting section;

[0026] Figure 6 yes Figure 2 A schematic diagram of a medium-pressure hydraulic piston pump without the oil circuit.

[0027] In the diagram: 1-Drive shaft, 2-Mounting base, 3-Inner shaft, 4-Spring seat, 5-Guide rod sleeve, 6-Return spring assembly, 7-Guide rod, 8-Housing, 9-Ball head support pin, 10-Swashplate assembly, 11-Follower piston, 12-Follower piston sleeve, 13-Rotor assembly, 14-Plunger assembly, 15-Oil distributor cover assembly, 16-Booster impeller assembly, 17-Impeller shaft, 18-Inlet pipe joint, 19-Solenoid valve, 20-Solenoid valve spring, 21-High pressure valve, 22-High pressure valve sleeve, 23-Spring guide rod, 24-Pressure adjusting spring, 25-Pressure adjusting screw sleeve, 26-Locking nut, 27-Pressure adjusting spring seat, 28-Adjusting cover, 30-Hydraulic plunger pump, 31-Return oil circuit, 32-Control chamber oil circuit, 33-Outlet oil circuit. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this invention. The embodiments can be combined with and referenced by each other without contradiction.

[0029] Example 1

[0030] like Figure 1 and 5The illustrated load-based adaptive constant-pressure variable hydraulic piston pump includes a connecting part and a hydraulic piston pump. The connecting part includes a mounting base 2. An inner shaft 3 extending into the inner cavity is rotatably mounted at the rear end of the mounting base 2. A drive shaft 1 for connecting to an engine is mounted inside the rear end of the inner shaft 3. An impeller shaft 17 is connected to and drives the impeller shaft 17. An inlet pipe connector 18 is fitted at the front end of the impeller shaft 17. A rotor assembly 13 is mounted on the inner shaft 3 within the mounting base 2, and the inner shaft 3 drives the rotor assembly 13 to rotate. A piston assembly 14 is inserted at the rear end of the rotor assembly 13. A swashplate assembly 10 is mounted against the rear end of the piston assembly 14. A cavity exists between the swashplate assembly 10 and the mounting base 2. A follower piston 11 is mounted at the front end of the outer edge of the swashplate assembly 10, pressing against the swashplate assembly 10 and installed in a follower piston sleeve 12. The follower piston sleeve 12 is fixed to the inner wall of the mounting base 2. The hydraulic piston pump includes an electromagnetic valve 1. 9. The electromagnetic valve 19 is electrically connected to the control box. The front end of the electromagnetic valve 19 has a high-pressure valve 21, which is fitted into the high-pressure valve sleeve 22. The electromagnetic valve spring 20 is fitted onto the electromagnetic valve 19 between the electromagnetic valve 19 and the high-pressure valve sleeve 22. The front end of the high-pressure valve sleeve 22 is connected to and installed with a spring guide rod 23, which is fitted into a pressure adjusting screw sleeve 25. The pressure adjusting screw sleeve 25 has a pressure adjusting spring seat 27 fixed inside its front end. A pressure adjusting spring 24 is installed between the spring guide rod 23 and the pressure adjusting spring seat 27. There is a chamber between the front end of the electromagnetic valve 19 and the rear end of the high-pressure valve sleeve 22, which is connected to the chamber between the plunger assembly 14 and the oil distributor assembly 15 through the outlet oil passage 33. The high-pressure valve sleeve 22 is divided into three parts: front, middle, and rear. There is a gap between the middle and rear parts, which is connected to the chamber between the follower piston 11 and the follower piston sleeve 12 through the control chamber oil passage 32.

[0031] Example 2

[0032] Based on Embodiment 1, the front middle part of the high-pressure valve sleeve 22 has a chamber on its side, which is connected to the cavity between the swash plate assembly 10 and the mounting base 2 through the return oil passage 31.

[0033] Furthermore, the front end of the pressure regulating screw sleeve 25 is fitted with an adjusting cap 28.

[0034] Furthermore, a locking nut 26 is fitted onto the pressure adjusting sleeve 25 along the bottom edge of the adjusting cover 28.

[0035] Furthermore, a housing 8 is fitted into a guide rod sleeve 5 at the position where the rear end face of the swashplate assembly 10 faces the follower piston 11, and the guide rod sleeve 5 is fixed to the inner wall of the mounting base 2.

[0036] Furthermore, a guide rod 7 is fitted onto the housing 8, and a return spring assembly 6 is fitted onto the outside of the guide rod 7. The two ends of the return spring assembly 6 are fixed to the guide rod sleeve 5 and the end of the housing 8, respectively.

[0037] Example 3

[0038] Based on Embodiment 1, the inner shaft 3 drives the impeller shaft 17 via a spline. A booster impeller assembly 16 is mounted on the impeller shaft 17 at the front end of the inner shaft 3, and the impeller shaft 17 drives the booster impeller assembly 16 via a spline.

[0039] Furthermore, the drive shaft 1 and the inner shaft 3 are connected by a spline drive.

[0040] Furthermore, the plunger assembly 14 is inserted into the plunger bore of the rotor assembly 13, which opens towards the rear end.

[0041] Furthermore, the inner shaft 3 and the rotor assembly 13 are connected by a spline drive.

[0042] Therefore, the main principle of this invention is that when it is necessary to adjust the constant pressure point of the hydraulic piston pump, the control system on the machine first needs to give a corresponding control signal. After receiving the control current, the electromagnet device will output a corresponding thrust to the high-pressure valve. When the outlet pressure approaches the set constant pressure value, under the action of the electromagnetic thrust and hydraulic pressure controlled by the preset pressure level control signal, the high-pressure valve will overcome the friction and the elastic force generated by the pressure regulating spring to move. After the high-pressure valve reaches a certain displacement, the high-pressure fluid at the outlet enters the follower piston chamber through the high-pressure valve. The piston moves under the action of the high-pressure fluid, and then the piston pushes the swashplate to reduce its swing angle, thereby ensuring that the hydraulic piston pump will not exceed the set constant pressure value.

[0043] Example 4

[0044] In conjunction with the above embodiments, such as Figures 1-3 As shown in Figure 6, when the engine 29 drives the transmission shaft 1 to rotate, the transmission shaft drives the inner shaft 3 to rotate through the spline. On the one hand, the inner shaft 3 drives the rotor assembly 13 to rotate through the spline. Due to the deflection angle of the swashplate assembly 10, the rotor assembly 13 and the plunger assembly 14 rotate around the inner shaft 3. At the same time, the plunger assembly 14 makes linear reciprocating motion in the plunger hole of the rotor assembly 13, thereby realizing the oil suction and discharge process of the engine-driven hydraulic plunger pump, and then supplying oil to the hydraulic system. On the other hand, the inner shaft 3 drives the impeller shaft 17 to rotate through the spline, thereby driving the booster impeller assembly 16 to rotate, thereby boosting the pressure of the inlet oil. (Explanation: Variable control section: The swashplate assembly 10 is mounted on the mounting base 2, the follower piston 11 is mounted inside the follower piston sleeve 12, and the follower piston sleeve 12 is mounted inside the housing. The movement of the follower piston 11 will drive the swashplate assembly 10 to rotate, thus realizing the variable control of the hydraulic piston pump. Heart transmission section: The rotor assembly 13 is connected to the inner shaft 3 via a spline, and the piston assembly 14 is mounted inside the piston hole of the rotor assembly 13. Pressure boosting section: The inner shaft 3 is connected to the impeller shaft 17 via a flat key, and the impeller shaft 17 is connected to the booster impeller 16 via a threaded connection.)

[0045] When the aircraft is taxiing on the ground (requiring medium-level pressure and full flow, corresponding to the 14MPa full flow state of the hydraulic plunger pump), the onboard control system sends a control signal requiring a constant pressure of 14MPa. The control box calculates the current required to be output to the electromagnetic valve 19 and outputs the corresponding current to it. Under the action of the current, the electromagnetic valve 19 generates a thrust of the corresponding magnitude. The theoretical magnitude of the thrust can be calculated using the following formula:

[0046]

[0047] In the formula The thrust required for the electromagnetic valve. For the spring stiffness of the electromagnetic valve ， For motion displacement, The cross-sectional area of ​​the valve is... Due to export pressure, For return oil pressure, The spring stiffness is adjusted. The thrust calculated using the above formula can be used to determine the current required for the electromagnetic valve. Since the pressure corresponding to the full flow is less than the opening pressure of the high-pressure valve 21, the hydraulic piston pump of the swashplate assembly 10 is always in the medium-pressure maximum displacement state under the return spring assembly 7 and the swashplate torque itself.

[0048] When the aircraft is in takeoff (requiring high-level pressure and high-flow, corresponding to the 28MPa level full-flow state of the hydraulic plunger pump), the onboard control system sends a control signal requiring a constant pressure of 28MPa. The control box calculates the current required to output to the solenoid valve 19 and outputs the corresponding current to it. The solenoid valve 19 generates a corresponding thrust under the influence of the current. Since the pressure corresponding to the full flow is less than the opening pressure of the high-pressure valve 21, the hydraulic plunger pump remains in the high-pressure maximum displacement state under the return spring assembly 7 and the return torque of the swashplate assembly 10.

[0049] When the aircraft is in the climb phase (requiring a higher level of pressure and a lower flow rate for pressure maintenance, corresponding to the 21MPa level and 0 flow rate state of the hydraulic plunger pump), since the hydraulic plunger pump still needs to maintain a constant pressure of 21MPa, a control signal requiring a constant pressure of 21MPa is issued. The control box calculates the current that needs to be output to the solenoid valve 19 and outputs the corresponding current to the solenoid valve 19. However, since the outlet pressure of the hydraulic plunger pump will now increase to 21MPa, under the hydraulic action of the high-pressure fluid at the outlet of the solenoid valve 19 and the high-pressure valve sleeve 22, the high-pressure valve 21 can overcome the elastic force of the pressure regulating spring 24 and move forward. At this time, the high-pressure fluid at the outlet of the high-pressure valve sleeve 22 will flow into the follower piston sleeve 12. After entering the sleeve, the high-pressure fluid will push the follower piston 11 to move forward. The movement of the follower piston 11 will push the swashplate assembly 10 to swing to a small swing angle. At this time, the hydraulic plunger pump completes the process of changing the full flow rate to 0 flow rate at the higher level of pressure.

[0050] When the aircraft is in cruise mode (requiring low-level pressure and low flow, corresponding to the 8MPa level 0 flow state of the hydraulic plunger pump), the onboard control system sends a control signal requiring a constant pressure of 8MPa. After calculating the current required to be output to the electromagnetic valve 19 through the control box, the corresponding current is output to the electromagnetic valve 19. Under the action of the current, the electromagnetic valve 19 will generate a thrust of the corresponding magnitude. Under the hydraulic action of the high-pressure fluid at the outlet of the electromagnetic valve 19 and the high-pressure valve sleeve 22, the high-pressure valve 21 can overcome the elastic force of the pressure regulating spring 24 and move forward. At this time, the high-pressure fluid at the outlet of the high-pressure valve sleeve 22 will flow into the follower piston sleeve 12. After entering the sleeve, the high-pressure fluid will push the follower piston 11 to move forward. The movement of the follower piston 11 will push the swashplate assembly 10 to swing to a small swing angle state. At this time, the hydraulic plunger pump completes the process of changing the full flow to 0 flow under the low-level pressure (8MPa).

[0051] This invention can significantly broaden the coverage range of the PQ curve of a hydraulic piston pump, such as... Figure 4 As shown.

[0052] Therefore, this invention can sense the actual pressure demand of the system load in real time and dynamically adjust the pump's output pressure to match the current operating conditions. This fundamentally eliminates the throttling or overflow losses caused by traditional constant pressure pumps maintaining excessively high constant pressure under most medium and low load conditions. This effectively reduces the energy consumption of the hydraulic system, improves the efficiency of aviation fuel use, and has significant economic and environmental value. It also effectively improves the thermal management of the hydraulic system and hydraulic piston pump. Since energy loss is significantly reduced at the source, the heat generated by throttling in the hydraulic system is also reduced accordingly. This helps control the temperature rise of the hydraulic oil and effectively slows down the aging rate of the hydraulic oil and seals, thereby improving the reliability and service life of the entire hydraulic system. At the same time, the dependence on and demand for the cooling system are also reduced, providing favorable conditions for aircraft weight reduction and simplified design. It also has high reliability. Through the presence of the electromagnetic valve spring, even if the electromagnetic valve loses thrust, it can still ensure that the hydraulic system can maintain the highest constant pressure level, i.e., the traditional constant pressure variable pump form. The failure of the newly added electromagnetic valve will not affect the safety of the hydraulic system.

[0053] Those skilled in the art will understand that the above embodiments can be modified in form and detail in practical applications without departing from the spirit and scope of the invention.

Claims

1. A load-based adaptive constant-pressure variable displacement hydraulic piston pump, characterized in that: The system includes a connecting part and a hydraulic plunger pump. The connecting part includes a mounting base (2). An inner shaft (3) extending into the inner cavity is mounted at the rear end of the mounting base (2). A drive shaft (1) for connecting to the engine is mounted inside the rear end of the inner shaft (3). The front end of the inner shaft (3) is connected to and drives an impeller shaft (17). An inlet pipe fitting (18) is fitted at the front end of the impeller shaft (17). A rotor assembly (13) is mounted on the inner shaft (3) inside the mounting base (2), and the inner shaft (3) drives the rotor assembly (13) to rotate. (13) A plunger assembly (14) is inserted at the rear end. A swashplate assembly (10) is installed against the rear end of the plunger assembly (14). There is a cavity between the swashplate assembly (10) and the mounting base (2). A follower piston (11) is located on the front end face of the outer edge of the swashplate assembly (10) and is installed against the swashplate assembly (10) and in the follower piston sleeve (12). The follower piston sleeve (12) is fixed to the inner side wall of the mounting base (2). The hydraulic plunger pump includes an electromagnetic valve (19). The electromagnetic valve (19) is electrically connected to the control box. The electromagnetic valve (19) has a high-pressure valve (21) at its front end. The high-pressure valve (21) is fitted into a high-pressure valve sleeve (22). An electromagnetic valve spring (20) is fitted between the electromagnetic valve (19) and the high-pressure valve sleeve (22). A spring guide rod (23) is connected and installed at the front end of the high-pressure valve sleeve (22). The spring guide rod (23) is fitted into a pressure adjusting screw sleeve (25). A pressure adjusting spring seat (27) is fixed inside the front end of the pressure adjusting screw sleeve (25). A pressure regulating spring (24) is installed between the guide rod (23) and the pressure regulating spring seat (27); there is a chamber between the front end of the electromagnetic valve (19) and the rear end of the high pressure valve sleeve (22), which is connected to the chamber between the plunger assembly (14) and the oil distribution cover assembly (15) through the outlet oil passage (33). The high pressure valve sleeve (22) is divided into three parts: front, middle and rear. There is a gap between the middle and rear parts, which is connected to the chamber between the follower piston (11) and the follower piston sleeve (12) through the control chamber oil passage (32).

2. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The high-pressure valve sleeve (22) has a chamber on the front middle part of its side, which is connected to the cavity between the swash plate assembly (10) and the mounting base (2) through the return oil passage (31).

3. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The front end of the pressure regulating screw sleeve (25) is fitted with an adjusting cover (28).

4. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 3, characterized in that: The bottom edge of the adjusting cover (28) has a locking nut (26) fitted onto the pressure adjusting screw sleeve (25).

5. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The rear end face of the swash plate assembly (10) facing the follower piston (11) has a housing (8) fitted in the guide rod sleeve (5), and the guide rod sleeve (5) is fixed to the inner wall of the mounting base (2).

6. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 5, characterized in that: A guide rod (7) is fitted on the housing (8), and a return spring assembly (6) is fitted on the outside of the guide rod (7). The two ends of the return spring assembly (6) are fixed to the guide rod sleeve (5) and the end of the housing (8), respectively.

7. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The inner shaft (3) drives the impeller shaft (17) via a spline. A booster impeller assembly (16) is mounted on the impeller shaft (17) at the front end of the inner shaft (3). The impeller shaft (17) drives the booster impeller assembly (16) via a spline.

8. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The drive shaft (1) and the inner shaft (3) are connected by a spline drive.

9. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The plunger assembly (14) is inserted into the plunger hole of the rotor assembly (13) which opens toward the rear end.

10. The load-based adaptive constant-pressure variable hydraulic piston pump as described in claim 1, characterized in that: The inner shaft (3) and the rotor assembly (13) are driven by splines.

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