Cam variable pump control system

Abstract

The invention discloses a cam variable pump control system which comprises a two-way variable pump, a variable cylinder, a reversing valve and a cam driving mechanism. The two-way variable pump comprises a rotationally arranged tilt cylinder, and the tilt cylinder is used for controlling the two-way variable pump to supply hydraulic oil to the hydraulic actuating mechanism; the variable cylinder assembly comprises a first variable cylinder and a second variable cylinder, and the telescopic end of the first variable cylinder and the telescopic end of the second variable cylinder are rotationally connected with the two opposite ends of the tilt cylinder correspondingly and arranged on the two sides of a tilt cylinder rotating point correspondingly; the reversing valve is provided with a first conduction position and a second conduction position, and based on rotation of the cam, a valve element of the reversing valve is switched between the first conduction position and the second conduction position. The stations of the reversing valve are directly switched through the cam driving mechanism, the number of control elements for a large-displacement pump in a large system is reduced, the number of control valve bodies is reduced, the interference of flow pulsation caused by valve opening and closing or working condition switching and the like in a hydraulic loop on the system is reduced, and the stability of the system is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of variable displacement pumps, and in particular relates to a cam variable displacement pump control system. Background Art

[0002] As the most widely used core power element in hydraulic systems, plunger pumps rely on the reciprocating motion of the plunger in the cylinder and the volume change caused by the angle change of the cylinder movement circle relative to the input shaft to achieve changes in suction and pressure oil. The common displacement change of plunger pumps is to control the displacement by controlling the swash plate. The existing variable displacement methods of plunger pumps are mostly to control the cylinder angle by controlling the swash plate or the swash shaft. The principle of controlling these two components is mostly some valve body control, which is easily affected by external interference, especially the flow pulsation of the entire circuit, which is particularly frequent in large and high-load equipment. Summary of the invention

[0003] The purpose of the present invention is to provide a cam variable pump control system to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above object, the present invention provides a cam variable pump control system, comprising:

[0005] A bidirectional variable pump, the bidirectional variable pump comprising a rotatably arranged swing cylinder, the swing cylinder being used to control the bidirectional variable pump to supply hydraulic oil to the hydraulic actuator;

[0006] A variable cylinder assembly, the variable cylinder assembly comprising a first variable cylinder and a second variable cylinder, wherein the telescopic end of the first variable cylinder and the telescopic end of the second variable cylinder are respectively rotatably connected to two opposite ends of the swing cylinder and are disposed on both sides of a rotation point of the swing cylinder;

[0007] A reversing valve, wherein the reversing valve is provided with an oil inlet end and an oil outlet end, and the reversing valve is connected with a first variable cylinder and a second variable cylinder; the valve core of the reversing valve has at least a first conducting position and a second conducting position:

[0008] When the valve core of the reversing valve is in the first conducting position, the first variable cylinder is connected to the oil inlet end, and the second variable cylinder is connected to the oil outlet end;

[0009] When the valve core of the reversing valve is in the second conducting position, the first variable cylinder is connected to the oil outlet, and the second variable cylinder is connected to the oil inlet;

[0010] A cam driving mechanism includes a cam and a cam driving element, wherein the cam driving element drives the cam to rotate, and based on the rotation of the cam, the valve core of the reversing valve is switched between the first conducting position and the second conducting position.

[0011] Optionally, the cam drive mechanism also includes a cam variable rod, which is rotationally connected to the valve core of the reversing valve; based on the rotation of the cam, the cam variable rod swings within a preset plane, so that the valve core of the reversing valve switches between the first conduction position and the second conduction position.

[0012] Optionally, the cam driving element includes a camshaft, which is detachably connected to the cam, and the cam is spirally extended along its own axis on the outer circumference to form a guide groove, the cam and the cam variable rod are rotatably connected in the guide groove, and the camshaft is driven by a motor.

[0013] Optionally, it also includes a rotating flange, which is detachably connected to the swing cylinder, and the telescopic end of the first variable cylinder and the telescopic end of the second variable cylinder are both rotatably connected to the rotating flange, and the telescopic end of the first variable cylinder and the telescopic end of the second variable cylinder are respectively arranged on both sides of the rotation point of the swing cylinder and the rotating flange.

[0014] Optionally, a sliding groove is formed at one end of the cam variable rod away from the cam driving element, and the rotating flange is rotatably connected to a pin shaft, and the pin shaft is movably arranged in the sliding groove.

[0015] Optionally, the reversing valve is a three-position four-way reversing valve, and the three-position four-way reversing valve includes a first conducting position, an intermediate position, and a second conducting position:

[0016] When the three-position four-way reversing valve is in the first conducting position, the first variable cylinder is connected to the oil inlet end, and the second variable cylinder is connected to the oil outlet end;

[0017] When the three-position four-way reversing valve is in the middle position, no hydraulic oil flows between the first variable cylinder and the second variable cylinder;

[0018] When the three-position four-way reversing valve is in the second conducting position, the first variable cylinder is connected to the oil outlet end, and the second variable cylinder is connected to the oil inlet end.

[0019] Optionally, it also includes:

[0020] A low-pressure relief valve, the inlet of which is connected to the oil circuit between the oil inlet end and the reversing valve;

[0021] A one-way valve, wherein the oil inlet end of the one-way valve is communicated with the oil outlet end of the low-pressure relief valve, and the oil outlet end of the one-way valve is communicated with the oil outlet pipeline of the two-way variable pump.

[0022] Optionally, the hydraulic actuator is a bidirectional variable motor.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The cam variable pump control system provided by the present invention realizes the switching between the first conduction position and the second conduction position of the reversing valve core by the rotation of the cam driving mechanism. When the reversing valve core is in different conduction positions, the oil inlet and outlet of the first variable cylinder and the second variable cylinder change, thereby pushing the telescopic end of the first variable cylinder and the telescopic end of the second variable cylinder to extend or retract. Since the telescopic ends of the first variable cylinder and the second variable cylinder are arranged on both sides of the swing cylinder rotation point, the telescopic ends of the first variable cylinder and the second variable cylinder push the swing cylinder to rotate, thereby controlling the flow direction and flow rate of the hydraulic oil supplied by the bidirectional variable pump to the hydraulic actuator. The present invention directly switches the working position of the reversing valve through the cam driving mechanism, reduces the number of control elements for large-displacement pumps in large systems, reduces the number of control valve bodies, reduces the interference of flow pulsation caused by valve opening and closing or working condition switching in the hydraulic circuit on the valve, reduces the interference of the valve on the system, and increases the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a schematic diagram of the structure of the cam variable pump control system of the present invention;

[0027] Figure 2 It is a schematic diagram of the first arrangement of the system structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the second arrangement of the system structure of the present invention.

[0029] Among them, 1. bidirectional variable pump, 2. first variable cylinder, 21. first variable piston, 3. second variable cylinder, 31. second variable piston, 4. reversing valve, 51. cam variable rod, 52. camshaft, 53. cam, 54. motor, 55. mounting seat, 56. pin shaft, 6. rotating flange, 7. low-pressure relief valve, 8. one-way valve, 9. bidirectional variable motor. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0031] like Figure 1-Figure 3 As shown, the present invention provides a cam variable pump control system, including a bidirectional variable pump 1, a variable cylinder, a reversing valve 4 and a cam driving mechanism.

[0032] The bidirectional variable pump 1 includes a rotatably arranged swing cylinder, which is used to control the bidirectional variable pump 1 to supply hydraulic oil to the hydraulic actuator; the variable cylinder assembly includes a first variable cylinder 2 and a second variable cylinder 3, the telescopic end of the first variable cylinder 2 and the telescopic end of the second variable cylinder 3 are respectively rotatably connected to the two opposite ends of the swing cylinder and are arranged on both sides of the rotation point of the swing cylinder; the reversing valve 4 is provided with an oil inlet end and an oil outlet end, and the reversing valve 4 is connected to the first variable cylinder 2 and the second variable cylinder 3.

[0033] The valve core of the reversing valve 4 has at least a first conducting position and a second conducting position: when the valve core of the reversing valve 4 is in the first conducting position, the first variable cylinder 2 is connected to the oil inlet end, and the second variable cylinder 3 is connected to the oil outlet end; when the valve core of the reversing valve 4 is in the second conducting position, the first variable cylinder 2 is connected to the oil outlet end, and the second variable cylinder 3 is connected to the oil inlet end; the cam driving mechanism, the cam driving mechanism includes a cam 53 and a cam driving element, the cam driving element drives the cam 53 to rotate, and based on the rotation of the cam 53, the valve core of the reversing valve 4 is switched between the first conducting position and the second conducting position.

[0034] The cam variable pump control system provided by the present invention drives the cam to rotate through the cam driving element to realize the switching of the first conduction position and the second conduction position of the reversing valve core. When the reversing valve core is in different conduction positions, the oil inlet and outlet of the first variable cylinder and the second variable cylinder change, thereby pushing the telescopic ends of the first variable cylinder 2 and the second variable cylinder 3 to extend or retract, and because the telescopic ends of the first variable cylinder 2 and the second variable cylinder 3 are arranged on both sides of the swing cylinder rotation point, the telescopic ends of the first variable cylinder 2 and the second variable cylinder 3 push the swing cylinder to rotate, thereby controlling the flow direction and flow rate of the hydraulic oil supplied by the bidirectional variable pump to the hydraulic actuator. The present invention directly switches the working position of the reversing valve through the cam driving mechanism, reduces the number of control elements for large-displacement pumps in large systems, reduces the number of control valve bodies, reduces the interference of flow pulsation caused by valve opening and closing or working condition switching in the hydraulic circuit on the system, and increases the stability of the system. The highly integrated system saves space and is convenient to be arranged on the whole vehicle.

[0035] The cam driving mechanism can use a cam to directly drive the reversing valve 4 to move, or the cam can drive other components to move and then drive the reversing valve 4 to move, so as to realize the switching between the first conduction position and the second conduction position of the valve core of the reversing valve 4. When the cam directly drives the reversing valve 4 to move, the following structure can be adopted: the cam driving mechanism includes a driving motor, the output shaft of the driving motor is detachably connected to the camshaft, the cam is mounted on the camshaft, the cam adopts a shape with different aspect ratios, such as an elliptical structure, and the outer circumference of the cam is provided with grooves with different aspect ratios, such as an elliptical groove, and a sliding member is embedded in the groove and slidably connected, the sliding member is rotatably connected to the valve core of the reversing valve, the valve core is slidably arranged inside the reversing valve, the plane where the sliding member is located is in the same plane as the plane where the valve core moves, and the cam is arranged on one side of the reversing valve, and the reversing valve is detachably connected to the entire device. During operation, the camshaft is driven to rotate by a driving motor, which in turn drives the cam to rotate. Since grooves with different length-width ratios are provided on the circumference of the outer periphery of the cam, the rotation of the cam drives the sliding member and the valve core to slide, and the sliding direction is consistent with the sliding direction of the valve core and the reversing valve, thereby realizing the switching of the reversing valve between the first conduction position and the second conduction position.

[0036] Preferably, when the cam drives other components to move and then drives the reversing valve 4 to move, the cam driving mechanism also includes a cam variable rod 51, and the cam variable rod 51 is rotatably connected to the valve core of the reversing valve 4; based on the rotation of the cam 53, the cam variable rod 51 swings in a preset plane, so that the valve core of the reversing valve 4 switches between the first conduction position and the second conduction position. Since the reversing valve is rotatably installed inside the system, the reversing valve can rotate relatively, so that the valve core and the reversing valve 4 are offset to adapt to the position change caused by the rotation of the cam variable rod 51, and ensure that the cam variable rod 51 can rotate normally. The cam variable rod 51 is driven to rotate by the cam driving element. Since the valve core is slidably arranged inside the reversing valve 4, the cam variable rod 51 drives the valve core to move inside the reversing valve 4, thereby realizing the switching of the first conduction position and the second conduction position of the reversing valve. In this embodiment, the valve core is fixedly connected to the driving rod, and one end of the driving rod is rotatably connected to the pin 56, and the pin 56 is rotatably connected to the cam variable rod 51, thereby realizing the rotation connection between the valve core and the cam variable rod 51. Of course, the rotational connection between the valve core and the cam variable rod 51 can also be achieved in other ways. For example, the valve core is fixedly connected to a drive bracket, and the drive bracket is parallel to the movement plane of the valve core, that is, the drive bracket and the movement plane of the valve core are in two parallel planes. The drive bracket and the cam variable rod 51 are rotationally connected through a pin shaft 56 or other components to ensure that the cam variable rod 51 can switch the working position of the reversing valve 4.

[0037] The cam driving element can choose direct drive or indirect drive to realize the rotation of the cam variable rod 51; for example, when the cam driving element chooses indirect drive, the cam driving element includes a motor, the output shaft of the motor is detachably connected to the camshaft, and the camshaft is detachably connected to the cam, and other transmission mechanisms such as a deflection wheel and a connecting rod are arranged between the cam and the cam variable rod 51 to convert the rotational motion of the cam into the rotational motion of the cam variable rod 51, and the cam variable rod 51 can only rotate within the moving plane of the valve core.

[0038] Further optimization scheme, the cam driving element includes a camshaft 52, the camshaft 52 is detachably connected with the cam 53, the cam 53 is spirally extended along its own axis to form a guide groove, the cam 53 is rotatably connected with the cam variable rod 51 in the guide groove, and the camshaft 52 is driven by the motor 54. The camshaft 52 is driven to rotate by the motor 54, and the rotation of the camshaft 52 drives the cam to rotate. Since the cam 53 is rotatably connected with the cam variable rod 51 in the guide groove, the guide groove is annular and inclinedly arranged on the circumference of the cam 53, and the cam variable rod 51 is rotatably connected with the valve core of the reversing valve 4, the position of the cam variable rod 51 is limited, ensuring that the cam variable rod 51 can only rotate in the moving plane of the valve core. There are fewer direct drive elements, the drive is more sensitive, and the operation is more convenient. Preferably, one end of the camshaft 52 is detachably connected with the output shaft of the motor 54 through a coupling, and the other end of the camshaft 52 is rotatably connected with the mounting seat 55 through a bearing, ensuring that the camshaft 52 can only rotate along its axis.

[0039] Further optimization scheme, a cam variable pump control system also includes a rotating flange 6, the rotating flange 6 is detachably connected to the swing cylinder, the telescopic end of the first variable cylinder 2 and the telescopic end of the second variable cylinder 3 are both rotatably connected to the rotating flange 6, and the telescopic end of the first variable cylinder 2 and the telescopic end of the second variable cylinder 3 are respectively arranged on both sides of the rotation point of the swing cylinder and the rotating flange 6. The rotating flange 6 is rigidly connected to the swing cylinder through nuts or screws and other components, so that the rotating flange 6 and the swing cylinder can move synchronously, that is, the rotating flange 6 and the swing cylinder can rotate synchronously with the swing cylinder rotation point, and the telescopic ends of the first variable cylinder 2 and the second variable cylinder 3 are respectively rotatably connected to the rotating flange 6 and are respectively arranged on both sides of the rotation point, ensuring that the changes in the inlet and outlet oil of the first variable cylinder 2 and the second variable cylinder 3 can rotate the rotating flange 6, thereby driving the swing cylinder to rotate.

[0040] Further optimization scheme, a sliding groove is provided at one end of the cam variable rod 51 away from the cam driving element, and the rotating flange 6 is rotatably connected with a pin 56, and the pin 56 is movably set in the sliding groove. The cam driving element drives the cam variable rod 51 to rotate, and the changes in the oil in and out of the first variable cylinder 2 and the second variable cylinder 3 drive the rotating flange 6 to rotate. The rotating flange 6 can drive the pin 56 to move in the sliding groove to ensure that the movement of the two will not interfere or get stuck, etc., and ensure that the cam variable rod 51 and the rotating flange 6 can rotate independently. Through the connection between the cam variable rod 51 and the rotating flange 6, it is ensured that the cam variable rod 51 can only move in the plane of the valve core movement, and the rotation angle of the rotating flange 6 and the swing cylinder is limited by the setting of the sliding groove.

[0041] To further optimize the solution, the reversing valve 4 is a three-position four-way reversing valve, and the three-position four-way reversing valve includes a first conducting position, an intermediate position and a second conducting position: when the three-position four-way reversing valve is in the first conducting position, the first variable cylinder 2 is connected to the oil inlet end, and the second variable cylinder 3 is connected to the oil outlet end; when the three-position four-way reversing valve is in the intermediate position, no hydraulic oil flows between the first variable cylinder 2 and the second variable cylinder 3; when the three-position four-way reversing valve is in the second conducting position, the first variable cylinder 2 is connected to the oil outlet end, and the second variable cylinder 3 is connected to the oil inlet end.

[0042] The three-position four-way reversing valve has three positions. In the first conduction position and the second conduction position, the oil inlet and outlet conditions of the first variable cylinder 2 and the second variable cylinder 3 change. When the three-position four-way reversing valve is in the middle position, there is no hydraulic oil inlet and outlet of the first variable cylinder 2 and the second variable cylinder 3, the swing angle of the swing cylinder of the two-way variable pump 1 is zero degrees, and no hydraulic oil flows out of the two-way variable pump 1, which is convenient for accurately controlling the rotation direction of the two-way variable pump 1 and controlling the flow rate of the two-way variable pump 1. Of course, the reversing valve in the present invention can also adopt a four-position four-way reversing valve, etc.

[0043] Further optimizing the scheme, a cam variable pump control system also includes a low-pressure relief valve 7 and a check valve 8. The inlet of the low-pressure relief valve 7 is connected to the oil inlet end and the oil circuit between the reversing valve 4; the oil inlet end of the check valve 8 is connected to the oil outlet end of the low-pressure relief valve 7, and the oil outlet end of the check valve 8 is connected to the oil outlet pipeline of the two-way variable pump 1.

[0044] In this embodiment, since the two-way variable pump 1 has two output oil circuits, at least two one-way valves 8 are provided. In this embodiment, two one-way valves 8 are provided, and the oil inlet ends of the two one-way valves 8 are both connected to the oil outlet end of the relief valve 7, and the oil outlet ends of the two one-way valves 8 are respectively connected to the two output oil circuits of the two-way variable pump 1. The low-pressure relief valve 7 can accurately adjust the pressure in the oil circuit between the oil inlet end and the reversing valve 4 to prevent equipment damage caused by excessive pressure, and transport the excess hydraulic oil to the main oil circuit through the one-way valve 8, and mix with the hydraulic oil supplied by the two-way variable pump 1 and then supply it to the hydraulic actuator.

[0045] In this embodiment, the hydraulic actuator is a bidirectional variable motor 9, and power is output through the bidirectional variable motor 9; of course, the hydraulic actuator can also be a bidirectional variable pump or other structures.

[0046] In this embodiment, the first variable cylinder 2 and the second variable cylinder 3 have the same structure and both include a hydraulic cylinder body, an oil storage chamber is provided inside the hydraulic cylinder body, the oil storage chamber is provided with an oil port, and is connected to the internal oil circuit of the reversing valve through the oil port; a variable piston is slidably arranged inside the hydraulic cylinder body, the variable piston of the first variable cylinder 2 is the first variable piston 21, and the variable piston of the second variable cylinder 3 is the second variable piston 31, the first variable piston 21 and the second variable piston 31 are respectively rotatably connected to the rotating flange 6, and are arranged on both sides of the rotation point of the swing cylinder and the rotating flange 6.

[0047] like Figure 1 The cam variable pump control system shown in the figure has the following working process:

[0048] When the bidirectional variable pump 1 is working, the hydraulic oil enters from the oil inlet end (P port), the initial position of the reversing valve 4 is the middle position, the swing angle of the swing cylinder in the bidirectional variable pump 1 is zero degree, and there is no flow output.

[0049] The output shaft of the motor 54 rotates clockwise, the camshaft 52 rotates clockwise, and the cam variable rod 51 is controlled to swing counterclockwise. The cam variable rod 51 drives the valve core of the reversing valve 4 to move right, and the reversing valve 4 is switched to the first conduction position (left position). The first variable cylinder 2 enters oil, the second variable cylinder 3 presses oil, the first variable piston 21 extends, the second variable piston 31 shortens, the rotating flange 6 and the swing cylinder swing counterclockwise. At the same time, the hydraulic oil entering the oil inlet end (P port) passes through the low-pressure relief valve 7, and then enters the main oil circuit of the hydraulic pump body after being selected by two one-way valves 8. After being mixed with the hydraulic oil at the oil outlet of the bidirectional variable pump 1, it is supplied to hydraulic actuators such as the bidirectional variable motor 9.

[0050] The output shaft of the motor 54 rotates counterclockwise, the camshaft 52 rotates counterclockwise, and the cam variable rod 51 is controlled to swing clockwise. The cam variable rod 51 drives the valve core of the reversing valve 4 to move left, and the reversing valve 4 is switched to the second conduction position (right position). The first variable cylinder 2 presses oil, and the second variable cylinder 3 takes in oil. The first variable piston 21 shortens, and the second variable piston 31 extends. The rotating flange 6 and the swing cylinder swing clockwise. At the same time, the hydraulic oil entering the oil inlet end (P port) passes through the low-pressure relief valve 7, and then enters the main oil circuit of the hydraulic pump body after being selected by two one-way valves 8. After being mixed with the hydraulic oil at the oil outlet of the bidirectional variable pump 1, it is supplied to hydraulic actuators such as the bidirectional variable motor 9.

[0051] The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for a person skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0052] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0053] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0054] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A cam variable pump control system, characterized in that: include: A bidirectional variable pump (1), the bidirectional variable pump (1) comprising a rotatably arranged swing cylinder, the swing cylinder being used to control the bidirectional variable pump (1) to supply hydraulic oil to a hydraulic actuator; A variable cylinder assembly, the variable cylinder assembly comprising a first variable cylinder (2) and a second variable cylinder (3), the telescopic end of the first variable cylinder (2) and the telescopic end of the second variable cylinder (3) being rotatably connected to two opposite ends of the swing cylinder respectively and being arranged on both sides of a rotation point of the swing cylinder; A reversing valve (4), the reversing valve (4) being provided with an oil inlet end and an oil outlet end, and the reversing valve (4) being in communication with the first variable cylinder (2) and the second variable cylinder (3); the valve core of the reversing valve (4) having at least a first conducting position and a second conducting position: When the valve core of the reversing valve (4) is in the first conducting position, the first variable cylinder (2) is connected to the oil inlet end, and the second variable cylinder (3) is connected to the oil outlet end; When the valve core of the reversing valve (4) is in the second conducting position, the first variable cylinder (2) is connected to the oil outlet, and the second variable cylinder (3) is connected to the oil inlet; A cam drive mechanism, the cam drive mechanism comprising a cam (53) and a cam drive element, the cam drive element driving the cam (53) to rotate, based on the rotation of the cam (53), the valve core of the reversing valve (4) is switched between the first conduction position and the second conduction position.

2. The cam variable pump control system according to claim 1, characterized in that: The cam drive mechanism further comprises a cam variable rod (51), wherein the cam variable rod (51) is rotatably connected to the valve core of the reversing valve (4); based on the rotation of the cam (53), the cam variable rod (51) swings within a preset plane, so that the valve core of the reversing valve (4) switches between the first conducting position and the second conducting position.

3. The cam variable pump control system according to claim 2, characterized in that: The cam driving element comprises a camshaft (52), wherein the camshaft (52) is detachably connected to the cam (53), wherein the cam (53) is spirally extended along its own axis in the outer circumference to form a guide groove, wherein the cam (53) is rotatably connected to the cam variable rod (51) in the guide groove, and the camshaft (52) is driven by a motor (54).

4. The cam variable pump control system according to claim 2, characterized in that: It also includes a rotating flange (6), which is detachably connected to the swing cylinder, and the telescopic end of the first variable cylinder (2) and the telescopic end of the second variable cylinder (3) are both rotatably connected to the rotating flange (6), and the telescopic end of the first variable cylinder (2) and the telescopic end of the second variable cylinder (3) are respectively arranged on both sides of the rotation point of the swing cylinder and the rotating flange (6).

5. The cam variable pump control system according to claim 4, characterized in that: A sliding groove is formed at one end of the cam variable rod (51) away from the cam driving element, and the rotating flange (6) is rotatably connected to a pin shaft (56), and the pin shaft (56) is movably arranged in the sliding groove.

6. The cam variable pump control system according to claim 1, characterized in that: The reversing valve (4) is a three-position four-way reversing valve, and the three-position four-way reversing valve comprises a first conducting position, an intermediate position and a second conducting position: When the three-position four-way reversing valve is in the first conducting position, the first variable cylinder (2) is connected to the oil inlet end, and the second variable cylinder (3) is connected to the oil outlet end; When the three-position four-way reversing valve is in the middle position, no hydraulic oil flows between the first variable cylinder (2) and the second variable cylinder (3); When the three-position four-way reversing valve is in the second conducting position, the first variable cylinder (2) is connected to the oil outlet, and the second variable cylinder (3) is connected to the oil inlet.

7. The cam variable pump control system according to claim 1, characterized in that: Also includes: A low-pressure relief valve (7), wherein the inlet of the low-pressure relief valve (7) is in communication with the oil circuit between the oil inlet end and the reversing valve (4); A one-way valve (8), wherein the oil inlet end of the one-way valve (8) is in communication with the oil outlet end of the low-pressure relief valve (7), and the oil outlet end of the one-way valve (8) is in communication with the oil outlet pipeline of the bidirectional variable pump (1).

8. The cam variable pump control system according to claim 1, characterized in that: The hydraulic actuator is a bidirectional variable motor (9).

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