Hydraulic pump displacement control device and hydraulic pump

Abstract

The application belongs to the technical field of hydraulic pump displacement control, and discloses a hydraulic pump displacement control device and a hydraulic pump. The hydraulic pump displacement control device comprises a control piston, a first oil cavity structure, a second oil cavity structure, a pressure oil source, a valve body, a valve core, an electric control thrust mechanism and a feedback mechanism. The control piston moves along the axial direction of the control piston to adjust the axial angle β between the swash plate and the plunger type hydraulic pump body. The end area of the first end of the control piston is smaller than the end area of the second end. The first end of the control piston extends into the first oil cavity structure, and the second end of the control piston extends into the second oil cavity structure. The valve core is arranged in the valve body. The electric control thrust mechanism pushes the valve core to move. The pressure oil source is connected to the first oil cavity structure and selectively connected to the second oil cavity structure under the movement of the valve core. The feedback mechanism is arranged in the valve body and acts under the driving of the control piston. The valve core is dynamically balanced under the action of the feedback mechanism and the electric control thrust mechanism. The hydraulic pump displacement control device can improve the response speed and accuracy of the hydraulic pump displacement control.

Description

Technical Field

[0001] This invention relates to the field of hydraulic pump displacement control technology, and in particular to a hydraulic pump displacement control device and a hydraulic pump. Background Technology

[0002] The displacement of a piston hydraulic pump can be adjusted by changing the angle β between the swashplate and the pump's axis. A larger angle β results in a smaller displacement, while a smaller angle β results in a larger displacement.

[0003] Traditional electronically controlled variable displacement hydraulic pumps typically use an electro-proportional pressure reducing valve for displacement control. The valve core of the displacement control device is moved by the pressure-reduced hydraulic oil, thereby achieving control. This results in the plunger hydraulic pump having an excessively slow adjustment response of the included angle β.

[0004] Therefore, there is an urgent need for a hydraulic pump displacement control device and a hydraulic pump to solve the above problems. Summary of the Invention

[0005] According to one aspect of the present invention, the object is to provide a hydraulic pump displacement control device and a hydraulic pump, the hydraulic pump displacement control device being able to improve the response speed and accuracy of hydraulic pump displacement control.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The hydraulic pump displacement control device includes:

[0008] A control piston, connected to a swashplate of the piston-type hydraulic pump body, is capable of moving along its own axis to adjust the angle β between the swashplate and the axis of the piston-type hydraulic pump body.

[0009] The first oil chamber structure and the second oil chamber structure are respectively the first end and the second end in the axial direction of the control piston. The end area of ​​the first end is smaller than the end area of ​​the second end. The first end can be movably extended into the first oil chamber structure and the second end can be movably extended into the second oil chamber structure.

[0010] The valve body comprises a valve core, an electrically controlled thrust mechanism, and a valve body. The valve core is disposed in the valve body, and the electrically controlled thrust mechanism is connected to the valve body and can drive the valve core to move. The first oil chamber structure can be connected to a pressure oil source. The valve body has a first pressure oil port and a second pressure oil port. The second pressure oil port is connected to the second oil chamber structure. The first pressure oil port is selectively connected to the second pressure oil port by the movement of the valve core.

[0011] A feedback mechanism is disposed in the valve body and connected between the control piston and the valve core. The feedback mechanism can be activated by the movement of the control piston, and the valve core can be dynamically balanced by the action of the feedback mechanism and the thrust of the electronically controlled thrust mechanism.

[0012] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the valve body is provided with a feedback mounting cavity and a valve core mounting cavity, and the first pressure oil port and the second pressure oil port are respectively connected to the valve core mounting cavity; the valve core is movably disposed in the valve core mounting cavity, and when the valve core is activated, it can selectively connect the first pressure oil port and the second pressure oil port. When the first pressure oil port and the second pressure oil port are connected, the pressure oil source is connected to the second oil cavity structure.

[0013] The feedback mechanism is installed in the feedback mounting cavity and connected to the valve core;

[0014] The electrically controlled thrust mechanism is located on the side of the valve core mounting cavity away from the feedback mounting cavity.

[0015] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the hydraulic pump displacement control device further includes an oil tank, and the valve body is also provided with a third pressure oil port. The third pressure oil port is connected to the valve core mounting cavity and the oil tank. When the valve core is activated, it can selectively connect the second pressure oil port and the third pressure oil port. When the second pressure oil port and the third pressure oil port are connected, the second oil cavity structure is connected to the oil tank.

[0016] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the feedback mechanism includes a guide structure, a feedback connection structure, and a feedback elastic element. The guide structure is fixedly disposed relative to the valve body. The feedback connection structure is connected to the control piston and sleeved outside the guide structure, and can move along the length direction of the guide structure. The feedback elastic element is connected between the feedback connection structure and the valve core, and the feedback elastic element can provide the valve core with an elastic force opposite to the thrust direction of the electronically controlled thrust mechanism.

[0017] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the feedback connection structure includes a movable part and a connecting part that are movably connected to each other. The movable part is movably sleeved outside the guide structure and can move along the length direction of the guide structure. The feedback elastic element is connected between the movable part and the valve core.

[0018] The feedback connection structure further includes a rotating connecting seat, which is fixed relative to the valve body. The connecting part is oscillatingly connected to the rotating connecting seat and movably connected to the control piston. The moving part moves in the opposite direction to the control piston.

[0019] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the feedback connection structure moves in the same direction as the control piston.

[0020] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the hydraulic pump displacement control device further includes an adjusting elastic element, which is coaxially arranged with the valve core and can provide the valve core with an elastic force opposite to the thrust direction of the electronically controlled thrust mechanism.

[0021] As a preferred embodiment of the hydraulic pump displacement control device provided by the present invention, the valve body has an elastic element mounting cavity, the hydraulic pump displacement control device further includes a first mounting seat, the valve core passes through the elastic element mounting cavity and is connected to the electric thrust mechanism, the first mounting seat is adjustablely positioned in the elastic element mounting cavity in the moving direction of the valve core, the adjusting elastic element is sleeved on the outside of the valve core, one end is connected to the first mounting seat, and the other end abuts against the valve core.

[0022] According to another aspect of the present invention, an object is to provide a hydraulic pump comprising a plunger-type hydraulic pump body and a hydraulic pump displacement control device as described in any of the above embodiments, wherein a swashplate of the plunger-type hydraulic pump body is connected to the control piston, and the included angle β between the swashplate and the axial direction of the plunger-type hydraulic pump body is adjustable by the control piston moving along its own axial direction.

[0023] As a preferred embodiment of the hydraulic pump provided by the present invention, the hydraulic pump further includes a pressure oil source and a shuttle valve. The shuttle valve includes a first inlet, a second inlet and a shuttle valve outlet. The first inlet and the second inlet are selectively connected to the shuttle valve outlet. The first inlet is connected to the pressure oil source, the second inlet is connected to the oil outlet of the plunger-type hydraulic pump body, and the shuttle valve outlet is connected to the first oil chamber structure and selectively connected to the second oil chamber structure.

[0024] The beneficial effects of this invention are:

[0025] The hydraulic pump displacement control device provided by this invention includes a control piston, a first oil chamber structure, a second oil chamber structure, a valve body, a valve core, an electrically controlled thrust mechanism, and a feedback mechanism. The control piston is connected to a swashplate of the piston-type hydraulic pump body and can move axially to adjust the angle β between the swashplate and the axial direction of the piston-type hydraulic pump body. The control piston has a first end and a second end at its two axial ends, respectively. The end area of ​​the first end is smaller than that of the second end. The first end is movably inserted into the first oil chamber structure, and the second end is movably inserted into the second oil chamber structure. Due to the difference in end areas at both ends of the control piston, and based on the principle that thrust equals the product of area and pressure, the thrust exerted by the pressurized oil in the first oil chamber structure on the first end and the thrust exerted by the pressurized oil in the second oil chamber structure on the second end will vary according to the different pressures in the first and second oil chamber structures. This allows the control piston to move, thereby causing the swashplate to swing, adjusting the angle β, and ultimately adjusting the displacement of the piston-type hydraulic pump body. By controlling the different end areas of the piston at both ends, the response speed and accuracy of hydraulic pump displacement control can be improved.

[0026] The valve core is disposed within the valve body, and the electrically controlled thrust mechanism is connected to the valve body, enabling the valve core to move. The first oil chamber structure is connected to a pressure oil source. The valve body has a first pressure oil port and a second pressure oil port, with the second pressure oil port connected to the second oil chamber structure. The first pressure oil port is selectively connected to the second pressure oil port by the movement of the valve core. By moving the valve core relative to the valve body, the connection and disconnection between the second oil chamber structure and the pressure oil source can be controlled, thereby changing the pressure in the second oil chamber structure and thus controlling the movement of the piston.

[0027] A feedback mechanism is located within the valve body, connecting the control piston and the valve core. This feedback mechanism operates under the influence of the control piston's movement, and the valve core dynamically balances itself under the combined action of the feedback mechanism and the thrust of the electrically controlled thrust mechanism. Through this feedback mechanism, changes in the control piston's position are accurately and rapidly fed back to the valve core, ensuring that both the valve core and the control piston are in a state of dynamic equilibrium. This, in turn, guarantees that the axial angle β between the swashplate and the piston-type hydraulic pump body remains balanced and stable.

[0028] The hydraulic pump provided by this invention can achieve precise adjustment of displacement through the aforementioned hydraulic pump displacement control device. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the hydraulic pump displacement control device provided in Embodiment 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of the hydraulic pump displacement control device provided in Embodiment 1 of the present invention in the start-up but not powered-on state;

[0032] Figure 3 This is a schematic diagram of the hydraulic pump displacement control device provided in Embodiment 1 of the present invention in the start-up and power-on state;

[0033] Figure 4 This is a schematic diagram of the hydraulic pump displacement control device and the hydraulic pump body provided in Embodiment 2 of the present invention.

[0034] In the picture:

[0035] 10. Piston-type hydraulic pump body; 11. Swashplate; 12. Oil drain port;

[0036] 100. Control piston; 110. First end; 120. Second end;

[0037] 210. First oil chamber structure; 220. Second oil chamber structure; 221. Throttling orifice;

[0038] 310. Valve body; 311. Feedback mounting cavity; 313. First pressure port; 314. Second pressure port; 315. Third pressure port; 316. Elastic element mounting cavity; 320. Valve core; 321. First annular groove; 322. Second annular groove; 323. Third annular groove; 330. Electrically controlled thrust mechanism; 340. Feedback mechanism; 341. Guide structure; 342. Feedback connection structure; 3421. Moving part; 3422. Connecting part; 3423. Rotating connecting seat; 343. Feedback elastic element; 344. Second mounting seat; 350. Adjusting elastic element; 360. First mounting seat; 370. Connecting rod; 380. Adjusting pin; 390. Locking nut;

[0039] 400, fuel tank;

[0040] 500, shuttle valve; 510, first inlet; 520, second inlet; 530, shuttle valve outlet; 540, inner core. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0046] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connect," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0048] In this embodiment, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, B and / or B can represent: B existing alone, B and B existing simultaneously, and B existing alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0049] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0050] Example 1

[0051] Figure 1 This diagram shows a hydraulic pump displacement control device provided in Embodiment 1 of the present invention. Figure 2 This diagram illustrates the hydraulic pump displacement control device provided in Embodiment 1 of the present invention in a start-up, unpowered state. Figure 3 This diagram illustrates the hydraulic pump displacement control device provided in Embodiment 1 of the present invention in the power-on startup state. (Refer to...) Figures 1-3 This embodiment provides a hydraulic pump displacement control device and a hydraulic pump. The hydraulic pump includes a plunger-type hydraulic pump body 10, a pressure oil source, and the hydraulic pump displacement control device provided in this embodiment.

[0052] One side of the swashplate 11 of the plunger hydraulic pump body 10 is connected to the control piston 100 via a connecting rod 370. The included angle β between the swashplate 11 and the axial direction of the plunger hydraulic pump body 10 can be adjusted by the movement of the control piston 100 along its own axial direction. The included angle β is proportional to the displacement of the plunger hydraulic pump body 10; a decrease in included angle β results in a decrease in the displacement of the plunger hydraulic pump body 10, while an increase in included angle β results in an increase in the displacement of the plunger hydraulic pump body 10. By changing the included angle β, the displacement of the plunger hydraulic pump body 10 can be adjusted, thereby outputting different flow rates through the oil outlet 12 of the plunger hydraulic pump body 10.

[0053] The hydraulic pump displacement control device includes a control piston 100, a first oil chamber structure 210, a second oil chamber structure 220, a valve body 310, a valve core 320, an electrically controlled thrust mechanism 330, and a feedback mechanism 340. The control piston 100 is connected to a swashplate 11 of the plunger-type hydraulic pump body 10 and is axially movable to adjust the angle β between the swashplate 11 and the axial direction of the plunger-type hydraulic pump body 10. The control piston 100 has a first end 110 and a second end 120 at its two axial ends. The end area of ​​the first end 110 is smaller than that of the second end 120. The first end 110 is movably inserted into the first oil chamber structure 210, and the second end 120 is movably inserted into the second oil chamber structure 220. By controlling the different end areas of the piston 100, and based on the principle that thrust equals the product of area and pressure, the thrust exerted by the pressurized oil in the first oil chamber structure 210 on the first end 110 and the thrust exerted by the pressurized oil in the second oil chamber structure 220 on the second end 120 will vary according to the different pressures in the first and second oil chamber structures 210 and 220. This allows for the control of the piston 100's movement, which in turn drives the swashplate 11 to swing, adjusting the included angle β, and thus regulating the displacement of the plunger-type hydraulic pump body 10. Controlling the piston 100's movement by varying the end areas at both ends improves the response speed and accuracy of hydraulic pump displacement control.

[0054] In this embodiment, when the control piston 100 moves toward the direction of the second oil chamber structure 220, the included angle β can increase, and when the control piston 100 moves toward the direction of the first oil chamber structure 210, the included angle β can decrease.

[0055] Furthermore, the valve core 320 is disposed in the valve body 310, and the electrically controlled thrust mechanism 330 is connected to the valve body 310, capable of driving the valve core 320 to move. When the electrically controlled thrust mechanism 330 is energized, it can apply a thrust toward the feedback mechanism 340 to the valve core 320. In this embodiment, the electrically controlled thrust mechanism 330 can specifically be an electromagnet from the prior art. The first oil chamber structure 210 can be connected to the pressure oil source of the hydraulic pump, and can be selectively connected to the second oil chamber structure 220 under the movement of the valve core 320. By moving the valve core 320 relative to the valve body 310, the connection and disconnection between the second oil chamber structure 220 and the pressure oil source can be controlled, thereby changing the pressure in the second oil chamber structure 220, thereby controlling the movement of the piston 100.

[0056] Furthermore, the feedback mechanism 340 is disposed within the valve body 310, connecting the control piston 100 and the valve core 320, and located on the side of the valve body 310 away from the electrically controlled thrust mechanism 330. The feedback mechanism 340 can operate under the movement of the control piston 100, applying a thrust towards the electrically controlled thrust mechanism 330 to the valve core 320. The valve core 320 can achieve dynamic balance under the action of the feedback mechanism 340 and the thrust of the electrically controlled thrust mechanism 330. Through the aforementioned feedback mechanism 340, the positional change of the control piston 100 can be accurately and quickly fed back to the valve core 320, thereby ensuring that both the valve core 320 and the control piston 100 are in a state of dynamic balance, thus guaranteeing that the included angle β between the swashplate 11 and the piston-type hydraulic pump body 10 remains balanced and stable.

[0057] Continue to refer to Figures 1-3 The valve body 310 has a feedback mounting cavity 311 and a valve core mounting cavity sequentially formed along the axial direction. The valve body 310 also has a first pressure port 313, a second pressure port 314, and a third pressure port 315 on the side corresponding to the valve core mounting cavity. The first pressure port 313, the second pressure port 314, and the third pressure port 315 are respectively connected to the valve core mounting cavity. The first pressure port 313 is selectively connected to a pressure oil source, and the second pressure port 314 is connected to the second oil chamber structure 220.

[0058] The feedback mechanism 340 is installed in the feedback mounting cavity 311 and is drively connected to the valve core 320. The electrically controlled thrust mechanism 330 is located on the side of the valve core mounting cavity away from the feedback mounting cavity 311. Along the direction away from the feedback mounting cavity 311 and close to the electrically controlled thrust mechanism 330, the first pressure port 313, the second pressure port 314, and the third pressure port 315 are arranged sequentially.

[0059] The valve core 320 is movably disposed in the valve core mounting cavity. When the valve core 320 is activated, it connects the first pressure port 313 and the second pressure port 314, or connects the second pressure port 314 and the third pressure port 315. When the first pressure port 313 and the second pressure port 314 are connected, the pressure oil source is connected to the second oil chamber structure 220, allowing the pressure oil in the pressure oil source to enter the second oil chamber structure 220. When the second pressure port 314 and the third pressure port 315 are connected, the second oil chamber structure 220 is disconnected from the pressure oil source, preventing the pressure oil in the pressure oil source from entering the second oil chamber structure 220.

[0060] Specifically, the valve core 320 has a first annular groove 321 and a second annular groove 322 spaced axially around its periphery. The first annular groove 321 and the second annular groove 322 are sequentially arranged without communication with each other, in a direction away from the feedback mounting cavity 311 and close to the electronically controlled thrust mechanism 330. When the valve core 320 moves relative to the valve body 310 such that the first pressure port 313 and the second pressure port 314 are within the range of the first annular groove 321, the first pressure port 313 and the second pressure port 314 can communicate through the first annular groove 321. When the valve core 320 moves relative to the valve body 310 such that the second pressure port 314 and the third pressure port 315 are within the range of the second annular groove 322, the second pressure port 314 and the third pressure port 315 can communicate through the second annular groove 322. It should be noted that when the first pressure port 313 and the second pressure port 314 are connected to the first annular groove 321, the second pressure port 314 will not be connected to the second annular groove 322. Similarly, when the second pressure port 314 and the third pressure port 315 are connected to the second annular groove 322, the second pressure port 314 will not be connected to the first annular groove 321. In other words, the second pressure port 314 can only be connected to either the first pressure port 313 or the second pressure port 314, and not simultaneously to both.

[0061] More specifically, the hydraulic pump also includes a shuttle valve 500. The shuttle valve 500 includes a first inlet 510, a second inlet 520, and a shuttle valve outlet 530, and has an inner core 540. The first inlet 510 and the second inlet 520 are selectively connected to the shuttle valve outlet 530. The first inlet 510 is connected to the pressure oil source, the second inlet 520 is connected to the oil outlet 12 of the plunger-type hydraulic pump body 10, and the shuttle valve outlet 530 is connected to the first oil chamber structure 210, and selectively connected to the second oil chamber structure 220 through the first pressure oil port 313 and the second pressure oil port 314. When the first inlet 510 is closed, the inner core 540 is located on the first inlet 510 side. When the plunger-type hydraulic pump body 10 is opened, the first inlet 510 is also opened. At this time, the pressure at the first inlet 510 is greater than the pressure at the oil outlet 12. The inner core 540 moves to the side of the second inlet 520. At this time, the first inlet 510 is connected to the shuttle valve outlet 530. At this time, the oil in the pressure oil source can flow through the shuttle valve outlet 530 to the first oil chamber structure 210, or simultaneously flow to the first oil chamber structure 210 and the second oil chamber structure 220.

[0062] More specifically, the hydraulic pump displacement control device also includes an oil tank 400. The third pressure port 315 is connected to the oil tank 400. When the second pressure port 314 and the third pressure port 315 are connected, the second oil chamber structure 220 is connected to the oil tank 400, allowing the pressurized oil in the second oil chamber structure 220 to be released, thereby reducing the pressure in the second oil chamber structure 220 to be lower than the pressure in the first oil chamber structure 210. At this time, the control piston 100 will move towards the location of the second oil chamber structure 220 under the action of the pressurized oil in the first oil chamber structure 210.

[0063] Preferably, a throttling orifice 221 is provided in the connecting oil passage between the second pressure port 314 and the second oil chamber structure 220. By providing the throttling orifice 221, the flow rate of the pressure oil can be reduced, thereby stabilizing the pressure.

[0064] Continue to refer to Figures 1-3 The hydraulic pump displacement control device also includes an adjusting elastic element 350. The adjusting elastic element 350 is coaxially arranged with the valve core 320 and can provide the valve core 320 with an elastic force opposite to the thrust direction of the electrically controlled thrust mechanism 330.

[0065] Specifically, the valve body 310 has an elastic element mounting cavity 316. The hydraulic pump displacement control device also includes a first mounting base 360, through which the valve core 320 passes and is connected to the electrically controlled thrust mechanism 330. The first mounting base 360 ​​is fixedly disposed in the elastic element mounting cavity 316. The adjusting elastic element 350 is sleeved on the valve core 320, with one end connected to the first mounting base 360 ​​and the other end abutting against the end boss of the valve core 320 near the electrically controlled thrust mechanism 330.

[0066] More specifically, the hydraulic pump displacement control device also includes an adjusting pin 380 and a locking nut 390. The adjusting pin 380 passes through the elastic element mounting cavity 316 and is provided with an eccentricity. Rotating the adjusting pin 380 can change the position of the first mounting seat 360 in the moving direction of the valve core 320, thereby changing the initial spring force of the adjusting elastic element 350 and improving the accuracy of the displacement control of the plunger-type hydraulic pump body 10.

[0067] Continue to refer to Figures 1-3The feedback mechanism 340 includes a guide structure 341, a feedback connection structure 342, and a feedback elastic element 343. The guide structure 341 is rod-shaped, fixedly disposed relative to the valve body 310, and parallel to the movement direction of the valve core 320. The feedback connection structure 342 is connected to the control piston 100 and sleeved outside the guide structure 341, and can move along the length of the guide structure 341. The feedback elastic element 343 is connected between the feedback connection structure 342 and the end of the valve core 320, and can provide the valve core 320 with a spring force opposite to the thrust direction of the electronically controlled thrust mechanism 330.

[0068] When the thrust generated by the input current of the electronically controlled thrust mechanism 330 is balanced with the elastic force of the adjusting elastic element 350 and the thrust of the feedback elastic element 343, the valve core 320 is in a balanced state, the swashplate 11 is in a stable state, the included angle β is determined, and the piston hydraulic pump body 10 outputs a stable flow.

[0069] Specifically, the valve core 320 is provided with a second mounting seat 344 at the end facing the guide structure 341. The second mounting seat 344 is used to support the feedback elastic element 343 and to feed back the elastic force of the feedback elastic element 343 to the valve core 320.

[0070] More specifically, in this embodiment, the feedback connection structure 342 is able to move in the same direction as the control piston 100.

[0071] When the plunger hydraulic pump body 10 is in operation and the hydraulic pump displacement control device is in the start-up but not powered-on state, and it is necessary to reduce the displacement of the plunger hydraulic pump body 10, the pressure at the first inlet 510 is greater than the pressure at the outlet 12. Part of the pressurized oil from the pressure oil source reaches the first oil chamber structure 210 through the first inlet 510 and the shuttle valve outlet 530, while another part reaches the second oil chamber structure 220 through the first inlet 510, the shuttle valve outlet 530, the first pressure oil port 313, the first annular groove 321, and the second pressure oil port 314. At this time, since the end area of ​​the first end 110 is smaller than the end area of ​​the second end 120, and the pressure in the first oil chamber structure 210 and the pressure in the second oil chamber structure 220 are basically the same, the control piston 100 can move towards the direction of the first oil chamber structure 210, thereby reducing the included angle β and decreasing the displacement of the plunger hydraulic pump body 10. When the thrust generated by the input current of the electronically controlled thrust mechanism 330 is balanced with the elastic force of the adjusting elastic element 350 and the thrust of the feedback elastic element 343, the valve core 320 is in a balanced state, the swashplate 11 is in a stable state, the included angle β is determined, and the piston hydraulic pump body 10 outputs a stable flow.

[0072] When the plunger hydraulic pump body 10 is in operation and the hydraulic pump displacement control device is powered on, and it is necessary to increase the displacement of the plunger hydraulic pump body 10, the thrust generated by the electro-controlled thrust mechanism 330 can push the valve core 320 to move towards the feedback mechanism 340, compressing the feedback elastic element 343 and the adjusting elastic element 350, so that the second pressure port 314 and the third pressure port 315 are connected. At this time, the pressure at the first inlet 510 is greater than the pressure at the outlet 12. A portion of the pressure oil in the pressure oil source flows through the first inlet 510 and the shuttle valve outlet 530 to the first pressure port 313 where it is cut off. The pressure oil in the second oil chamber structure 220 enters the oil tank 400 through the second pressure port 314, the second annular groove 322 and the third pressure port 315. The other portion of the pressure oil in the pressure oil source reaches the first oil chamber structure 210 through the first inlet 510 and the shuttle valve outlet 530. At this time, the pressurized oil in the first oil chamber structure 210 can push the control piston 100, causing it to move towards the second oil chamber structure 220, thereby increasing the included angle β and increasing the displacement of the plunger hydraulic pump body 10. When the thrust generated by the input current of the electronically controlled thrust mechanism 330 is balanced with the elastic force of the adjusting elastic element 350 and the thrust of the feedback elastic element 343, the valve core 320 is in a balanced state, the swashplate 11 is in a stable state, the included angle β is determined, and the plunger hydraulic pump body 10 outputs a stable flow rate.

[0073] In other words, in this embodiment, since the thrust of the electronically controlled thrust mechanism 330 on the valve core 320, the elastic force of the adjusting elastic element 350 on the valve core 320, and the thrust of the feedback elastic element 343 on the valve core 320 are constantly being balanced, and the thrust of the feedback elastic element 343 comes from the movement of the control piston 100, as the input current of the electronically controlled thrust mechanism 330 increases, the displacement of the piston hydraulic pump body 10 can gradually increase, that is, electronically controlled proportional displacement control is realized.

[0074] Example 2

[0075] This embodiment provides a hydraulic pump displacement control device and a hydraulic pump.

[0076] Figure 4 A schematic diagram of the hydraulic pump displacement control device and the hydraulic pump body provided in Embodiment 2 of the present invention is shown. (Refer to...) Figure 4 The difference between this embodiment and embodiment one is that the structure and feedback principle of the feedback connection structure 342 of the hydraulic pump displacement control device provided in this embodiment are different from those in embodiment one, and the structure of the valve core 320 of the hydraulic pump displacement control device provided in this embodiment is different from that in embodiment one.

[0077] Specifically, in this embodiment, the valve core 320 has only one third annular groove 323 on its periphery. By changing the position of the valve core 320, the third annular groove 323 can be connected to the first pressure port 313 and the second pressure port 314, or the third annular groove 323 can also be connected to the second pressure port 314 and the third pressure port 315.

[0078] When the third annular groove 323 is connected to the first pressure oil port 313 and the second pressure oil port 314, a portion of the pressure oil from the pressure oil source can enter the second oil chamber structure 220 through the first inlet 510, the shuttle valve outlet 530, the first pressure oil port 313, the third annular groove 323 and the second pressure oil port 314; another portion of the pressure oil from the pressure oil source can enter the first oil chamber structure 210 through the first inlet 510 and the shuttle valve outlet 530.

[0079] When the third annular groove 323 is connected to the second pressure port 314 and the third pressure port 315, a portion of the pressure oil from the pressure oil source can enter the first oil chamber structure 210 through the first inlet 510 and the shuttle valve outlet 530, while another portion of the pressure oil from the pressure oil source flows through the first inlet 510 and the shuttle valve outlet 530 to the first pressure port 313 where it is cut off. At this time, the pressure oil in the second oil chamber structure 220 can enter the oil tank 400 through the second pressure port 314, the third annular groove 323, and the third pressure port 315.

[0080] More specifically, in this embodiment, the feedback connection structure 342 includes a movable part 3421 and a connecting part 3422 that are movably connected to each other. The movable part 3421 is movably sleeved on the guide structure 341 and can move along the length direction of the guide structure 341. The feedback elastic element 343 is connected between the movable part 3421 and the valve core 320. The feedback connection structure 342 also includes a rotating connecting seat 3423, which is fixed relative to the valve body 310. The connecting part 3422 is swayably connected to the rotating connecting seat 3423 and is movably connected to the control piston 100. With the above configuration, the movable part 3421 can move in the opposite direction to the control piston 100.

[0081] When the plunger hydraulic pump body 10 is in operation and the hydraulic pump displacement control device is in a powered-off state, and it is necessary to reduce the displacement of the plunger hydraulic pump body 10, the pressure at the first inlet 510 is greater than the pressure at the outlet 12. Part of the pressurized oil from the pressure oil source reaches the first oil chamber structure 210 through the first inlet 510 and the shuttle valve outlet 530, while another part reaches the second oil chamber structure 220 through the first inlet 510, the shuttle valve outlet 530, the first pressure oil port 313, the third annular groove 323, and the second pressure oil port 314. At this time, since the end area of ​​the first end 110 is smaller than the end area of ​​the second end 120, and the pressure in the first oil chamber structure 210 and the pressure in the second oil chamber structure 220 are basically the same, the control piston 100 can move towards the direction of the first oil chamber structure 210, thereby reducing the included angle β and decreasing the displacement of the plunger hydraulic pump body 10. When the thrust generated by the input current of the electronically controlled thrust mechanism 330 is balanced with the elastic force of the adjusting elastic element 350 and the thrust of the feedback elastic element 343, the valve core 320 is in a balanced state, the swashplate 11 is in a stable state, the included angle β is determined, and the piston hydraulic pump body 10 outputs a stable flow.

[0082] When the plunger hydraulic pump body 10 is in operation and the hydraulic pump displacement control device is powered on, and it is necessary to increase the displacement of the plunger hydraulic pump body 10, the thrust generated by the electrically controlled thrust mechanism 330 pushes the valve core 320 toward the feedback mounting cavity 311. The feedback mounting cavity 311 is disengaged from the range of the third annular groove 323, and the first pressure port 313 and the second pressure port 314 are connected through the third annular groove 323. At this time, a portion of the pressure oil at the first inlet 510 enters the first oil chamber structure 210 through the shuttle valve outlet 530, and the other portion of the pressure oil at the first inlet 510 reaches the second oil chamber structure 220 through the shuttle valve outlet 530, the first pressure port 313, the third annular groove 323, and the second pressure port 314, so as to push the control piston 100 toward the first oil chamber structure 210, reduce the included angle β, and reduce the displacement of the plunger hydraulic pump body 10. When the thrust generated by the input current of the electronically controlled thrust mechanism 330 is balanced with the elastic force of the adjusting elastic element 350 and the thrust of the feedback elastic element 343, the valve core 320 is in a balanced state, the swashplate 11 is in a stable state, the included angle β is determined, and the piston hydraulic pump body 10 outputs a stable flow.

[0083] In other words, in this embodiment, since the thrust of the electronically controlled thrust mechanism 330 on the valve core 320, the elastic force of the adjusting elastic element 350 on the valve core 320, and the thrust of the feedback elastic element 343 on the valve core 320 are constantly being balanced, and the thrust of the feedback elastic element 343 comes from the movement of the control piston 100, as the input current of the electronically controlled thrust mechanism 330 increases, the displacement of the plunger hydraulic pump body 10 can gradually decrease, that is, electronically controlled negative proportional displacement control is achieved.

[0084] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A hydraulic pump displacement control device, characterized in that, include: The control piston (100) is connected to the swashplate (11) of the piston-type hydraulic pump body (10) and can move along its own axis to adjust the angle β between the swashplate (11) and the axis of the piston-type hydraulic pump body (10). The first oil chamber structure (210) and the second oil chamber structure (220) are respectively the first end (110) and the second end (120) in the axial direction of the control piston (100). The end area of ​​the first end (110) is smaller than the end area of ​​the second end (120). The first end (110) is movably extended into the first oil chamber structure (210), and the second end (120) is movably extended into the second oil chamber structure (220). The valve body (310), valve core (320), and electrically controlled thrust mechanism (330) are provided. The valve core (320) is disposed in the valve body (310). The electrically controlled thrust mechanism (330) is connected to the valve body (310) and can drive the valve core (320) to move. The first oil chamber structure (210) can be connected to a pressure oil source. The valve body (310) has a first pressure oil port (313) and a second pressure oil port (314). The second pressure oil port (314) is connected to the second oil chamber structure (220). The first pressure oil port (313) is selectively connected to the second pressure oil port (314) through the movement of the valve core (320). A feedback mechanism (340) is disposed in the valve body (310) and connected between the control piston (100) and the valve core (320). The feedback mechanism (340) can move under the movement of the control piston (100), and the valve core (320) can be dynamically balanced under the action of the feedback mechanism (340) and the thrust of the electronically controlled thrust mechanism (330). The feedback mechanism (340) includes a guide structure (341), a feedback connection structure (342), and a feedback elastic element (343). The guide structure (341) is fixedly disposed relative to the valve body (310). The feedback connection structure (342) is connected to the control piston (100) and sleeved outside the guide structure (341), and can move along the length direction of the guide structure (341). The feedback elastic element (343) is connected between the feedback connection structure (342) and the valve core (320). The feedback elastic element (343) can provide the valve core (320) with an elastic force opposite to the thrust direction of the electronically controlled thrust mechanism (330). The feedback connection structure (342) includes a movable part (3421) and a connecting part (3422) that are movably connected to each other. The movable part (3421) is movably sleeved on the guide structure (341) and can move along the length direction of the guide structure (341). The feedback elastic element (343) is connected between the movable part (3421) and the valve core (320). The feedback connection structure (342) further includes a rotating connection seat (3423), which is fixed relative to the valve body (310). The connecting part (3422) is swayably connected to the rotating connection seat (3423), and the connecting part (3422) is movably connected to the control piston (100). The moving part (3421) moves in the opposite direction to the control piston (100).

2. The hydraulic pump displacement control device according to claim 1, characterized in that, The valve body (310) has a feedback mounting cavity (311) and a valve core mounting cavity. The first pressure oil port (313) and the second pressure oil port (314) are respectively connected to the valve core mounting cavity. The valve core (320) is movably disposed in the valve core mounting cavity. When the valve core (320) is activated, it can selectively connect the first pressure oil port (313) and the second pressure oil port (314). When the first pressure oil port (313) and the second pressure oil port (314) are connected, the pressure oil source is connected to the second oil cavity structure (220). The feedback mechanism (340) is installed in the feedback mounting cavity (311) and connected to the valve core (320). The electrically controlled thrust mechanism (330) is located on the side of the valve core mounting cavity away from the feedback mounting cavity (311).

3. The hydraulic pump displacement control device according to claim 2, characterized in that, The hydraulic pump displacement control device also includes an oil tank (400), and the valve body (310) is also provided with a third pressure oil port (315). The third pressure oil port (315) is connected to the valve core mounting cavity and the oil tank (400). When the valve core (320) is activated, it can selectively connect the second pressure oil port (314) and the third pressure oil port (315). When the second pressure oil port (314) and the third pressure oil port (315) are connected, the second oil chamber structure (220) is connected to the oil tank (400).

4. The hydraulic pump displacement control device according to claim 1, characterized in that, The feedback connection structure (342) moves in the same direction as the control piston (100).

5. The hydraulic pump displacement control device according to any one of claims 1-4, characterized in that, The hydraulic pump displacement control device also includes an adjusting elastic element (350), which is coaxially arranged with the valve core (320) and can provide the valve core (320) with an elastic force opposite to the thrust direction of the electronically controlled thrust mechanism (330).

6. The hydraulic pump displacement control device according to claim 5, characterized in that, The valve body (310) has an elastic element mounting cavity (316). The hydraulic pump displacement control device also includes a first mounting seat (360). The valve core (320) passes through the elastic element mounting cavity (316) and is connected to the electric thrust mechanism (330). The first mounting seat (360) is adjustablely positioned in the elastic element mounting cavity (316) in the moving direction of the valve core (320). The adjusting elastic element (350) is sleeved on the valve core (320), with one end connected to the first mounting seat (360) and the other end abutting against the valve core (320).

7. A hydraulic pump, characterized in that, The device includes a piston-type hydraulic pump body (10) and a hydraulic pump displacement control device as described in any one of claims 1-6, wherein the swashplate (11) of the piston-type hydraulic pump body (10) is connected to the control piston (100), and the included angle β between the swashplate (11) and the axial direction of the piston-type hydraulic pump body (10) is adjustable by the control piston (100) moving along its own axial direction.

8. The hydraulic pump according to claim 7, characterized in that, The hydraulic pump also includes a pressure oil source and a shuttle valve (500). The shuttle valve (500) includes a first inlet (510), a second inlet (520), and a shuttle valve outlet (530). The first inlet (510) and the second inlet (520) are selectively connected to the shuttle valve outlet (530). The first inlet (510) is connected to the pressure oil source, and the second inlet (520) is connected to the oil outlet (12) of the piston hydraulic pump body (10). The shuttle valve outlet (530) is connected to the first oil chamber structure (210) and selectively connected to the second oil chamber structure (220).

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