Integrated filtering system for pump and control method

Abstract

The invention discloses an integrated filtering system for a pump and a control method. The integrated filtering system for the pump comprises a filter, a safety valve, an electronic differential pressure valve, a controller and a variable control valve. An oil inlet of the filter is connected to an oil outlet of the oil supplementing pump, and an oil outlet of the filter is connected to a first opening and a second opening of the plunger pump. The electronic differential pressure valve is used for detecting the differential pressure between an oil inlet and an oil outlet of the filter; the controller is configured to obtain the pressure difference between the oil inlet and the oil outlet of the filter; comparing the pressure difference with a preset value; when the pressure difference is larger than or equal to a first set value, an alarm module is controlled to give an alarm; and in response to the fact that the pressure difference is larger than or equal to a second set value, electromagnets at the two ends of the variable control valve are controlled to lose power and return to the neutral position, the plunger pump swash plate swing angle is driven to return to the zero position, and the theoretical output flow of the plunger pump is zero. And predicting according to the pressure difference to obtain the residual service life of the filter element of the filter and displaying the residual service life to remind to replace the filter element.

Description

Technical Field

[0001] The invention relates to an integrated filter system for a pump and a control method thereof, and belongs to the field of hydraulic pumps. Background Art

[0002] With the development of technology, the electrification integration of hydraulic systems in the agricultural machinery field is becoming increasingly higher, and higher reliability requirements are placed on the hydraulic systems. The core of the entire agricultural machinery hydraulic system is the hydraulic pump.

[0003] Since agricultural machinery often operates in mountains and fields, the working environment is relatively harsh and the oil cleanliness of the entire hydraulic system is easily exceeded; therefore, traditional hydraulic pumps are easily contaminated by oil, causing particulate impurities to enter the pump's rotor, resulting in damage to the hydraulic pump.

[0004] The prior art has the following disadvantages: (1) The prior art solution does not consider the problem of hydraulic pump failure caused by impurities clogging the filter after the filter element has been used for a period of time. Therefore, there is no early warning and prompt for filter replacement. Once the filter element is blocked, it will directly lead to the problem of suction in the plunger cavity of the hydraulic pump, thereby causing damage to the hydraulic pump. (2) Once the filter element is blocked and the hydraulic pump suddenly stops working, it may not only cause economic losses from stopping operations, but also cause the main machine to suddenly stop during operation due to the failure, resulting in operational risks that affect personal safety. (3) The filter element is inconvenient to replace. Summary of the invention

[0005] Purpose: In view of at least one of the above technical problems, the present invention provides an integrated filtration system and control method for a pump, which is integrated with an electronic pressure differential valve, which can effectively prevent foreign particles in the oil tank from entering the hydraulic pump cavity along with the hydraulic oil and causing irreversible damage to the pump.

[0006] According to one aspect of the present application, there is provided an integrated filtration system for a pump, comprising an oil charge pump, a variable piston and a plunger pump swash plate, a filter, a safety valve, an electronic differential pressure valve, a controller and a variable control valve; The oil inlet of the filter is connected to the oil outlet of the oil replenishment pump, and the oil outlet of the filter is respectively connected to the first port and the second port of the plunger pump; one end of the electronic differential pressure valve is connected to the oil inlet of the filter, and the other end is connected to the oil outlet of the filter, and is used to detect the pressure difference between the oil inlet and the oil outlet of the filter, and upload the pressure difference to the controller; the electronic differential pressure valve is connected to the controller signal; The inlet of the variable control valve is connected to the oil outlet of the filter, the first working oil port is connected to the first chamber of the variable piston, the second working oil port is connected to the second chamber of the variable piston, and the electromagnets at both ends of the variable control valve are connected to the controller signal; the plunger pump swash plate is rigidly connected to the variable piston; and is used to control the displacement of the variable piston through the variable control valve, thereby adjusting the output flow of the plunger pump; The variable control valve is an electric proportional reversing valve and has at least a first working position, a second working position and a middle position; when the variable control valve is in the first working position or the second working position, the hydraulic oil enters the first chamber and the second chamber of the variable piston through the variable control valve, thereby driving the swash plate of the plunger pump to move, so that the output flow of the plunger pump changes; when the variable control valve is in the middle position, no hydraulic oil enters the first chamber and the second chamber of the variable piston, the variable piston is in the middle position, and the theoretical output flow of the plunger pump is zero; The controller is configured to: obtain a pressure difference between an oil inlet and an oil outlet of the filter; compare the pressure difference with a preset value; the preset value includes a first set value and a second set value, and the first set value is less than the second set value; In response to the pressure difference being greater than or equal to a first set value, controlling the alarm module to issue an alarm; In response to the pressure difference being greater than or equal to the second set value, the electromagnets at both ends of the control variable control valve lose power and return to the middle position, driving the swash plate angle of the plunger pump to return to the zero position, and the theoretical output flow of the plunger pump is zero.

[0007] In some embodiments, the integrated filtration system for a pump further includes a filter element life prediction module, which is used to: predict the remaining service life of the filter element based on the pressure difference.

[0008] Furthermore, in some embodiments, the filter element life prediction module is specifically used to: According to the pressure difference, a filter element life prediction model is used to predict the filter element use time prediction value; wherein the filter element life prediction model stores a linear relationship between the pressure difference between the oil inlet and the oil outlet of the filter and the filter element use time; The remaining service life of the filter element is obtained according to the predicted value of the filter element usage time and the preset total service life of the filter element.

[0009] Furthermore, in some embodiments, the integrated filtration system for a pump further includes a display module connected to the controller signal for displaying the remaining service life of the filter element.

[0010] In some embodiments, the integrated filter system for the pump further comprises a safety valve, wherein a first end of the safety valve is connected to the oil inlet of the filter (the oil outlet of the replenishing pump), a second end of the safety valve is connected to the oil suction port of the replenishing pump, and a control end of the safety valve is connected to the oil outlet of the filter; when the pressure difference between the oil inlet and the oil outlet of the filter is greater than or equal to a third set value, the safety valve changes from a closed state to an open state, and the oil at the oil inlet of the filter (the oil outlet of the replenishing pump) is directly returned to the oil suction port of the replenishing pump through the safety valve; wherein the third set value is greater than the second set value.

[0011] In some embodiments, the variable control valve is a three-position four-way electric proportional reversing valve; When the first end solenoid of the variable control valve is energized, the hydraulic oil passes through the first working position (left position) of the variable control valve and enters the first chamber (left chamber) of the variable piston. The variable piston moves to the right, pushing the swash plate of the plunger pump to move from the middle position to the positive direction of maximum displacement. When the solenoid at the second end of the variable control valve is energized, the hydraulic oil passes through the second working position (right position) of the variable control valve and enters the second chamber (right chamber) of the variable piston. The variable piston moves to the left, pushing the swash plate of the plunger pump to move from the middle position to the negative direction of the maximum displacement. When both the first end electromagnet and the second end electromagnet of the variable control valve are not energized, the variable control valve is in the middle position, the variable piston drives the swash plate of the plunger pump to swing back to the zero position, and the theoretical output flow of the plunger pump is zero.

[0012] In some embodiments, the oil outlet of the filter of the pump integrated filtration system is further provided with an oil replenishment relief valve, a first relief valve is provided between the oil outlet of the filter and the first port of the plunger pump, and a second relief valve is provided between the oil outlet of the filter and the second port of the plunger pump, the first relief valve and the second relief valve have the same structure and have at least a first working state and a second working state; In the first working state, the first port of the first relief valve and the second relief valve is unidirectionally connected to the second port through the one-way valve in the valve, and the hydraulic oil at the oil outlet of the filter is replenished to the low-pressure side of the main oil circuit of the plunger pump through the first relief valve or the second relief valve; When the oil pressure on the high-pressure side of the main oil circuit of the plunger pump exceeds the fourth set value, the corresponding first overflow valve or the second overflow valve is in the second working state, the second port is connected to the first port, and the hydraulic oil on the high-pressure side of the main oil circuit is unloaded back to the oil tank through the oil replenishment overflow valve.

[0013] In some embodiments, the integrated filter system for a pump further comprises a filter seat, and the filter, the safety valve, and the electronic differential pressure valve are mounted on the filter seat.

[0014] Furthermore, in some embodiments, the filter seat has at least one of the following structures: a mounting surface structure matching with a plate-type electronic differential pressure valve, and a mounting hole structure matching with a threaded plug-in electronic differential pressure valve.

[0015] According to another aspect of the present application, a control method for a pump-integrated filtration system is provided, wherein the pump-integrated filtration system is the above-mentioned pump-integrated filtration system, and the control method comprises: Obtain the pressure difference between the oil inlet and the oil outlet of the filter; Comparing the pressure difference with a preset value; the preset value includes a first set value and a second set value, and the first set value is smaller than the second set value; In response to the pressure difference being greater than or equal to a first set value, controlling the alarm module to issue an alarm; In response to the pressure difference being greater than or equal to the second set value, the electromagnets at both ends of the control variable control valve lose power and return to the middle position, so as to drive the swash plate angle of the plunger pump to return to the zero position, and the theoretical output flow of the plunger pump is zero; The remaining service life of the filter element is predicted based on the pressure difference, and is sent to the display module to display the remaining service life of the filter element.

[0016] The beneficial effects achieved by the present invention are as follows: the present invention provides an integrated filtering system integrated on a hydraulic pump, which is equipped with an electronic pressure differential valve. The electronic pressure differential valve monitors the pressure difference between the oil inlet and the oil outlet of the filter, thereby starting an alarm prompt when the set value is reached, controlling the variable control valve to return to the center position, and avoiding damage to the pump body of the plunger pump due to air suction; in addition, it also has the function of predicting the service life of the filter element and warning of replacement, which can not only show the predicted remaining service life in daily use, but also provide warning prompts to replace the filter element, thereby ensuring that the machine owner does not suffer operational economic losses and personal safety risks caused by sudden shutdown due to blockage of the filter element in the filtering system integrated in the hydraulic pump, but also maximizes the use of the entire life cycle of the filter element, thereby reducing the maintenance and use costs of the entire machine; when the filter element is blocked, the oil at the oil inlet of the filter can be returned to the oil suction port of the oil replenishment pump through the safety valve, thereby avoiding component damage caused by pressure buildup. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of an integrated filter system for a pump according to an embodiment of the present invention; In the figure: filter seat 1, filter 2, safety valve 3, electronic differential pressure valve 4, controller 5, central control panel 6, buzzer alarm 7, variable control valve 8, variable piston 9, plunger pump swash plate 10, oil replenishment pump 11, first overflow valve 12, second overflow valve 13, oil replenishment overflow valve 14. DETAILED DESCRIPTION

[0018] The present application is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and cannot be used to limit the protection scope of the present application.

[0019] In the description of this application, "several" means more than one, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0020] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0021] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0022] It should be noted that similar symbols and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

[0023] In order to solve the problem that oil contamination in the existing plunger pump causes particulate impurities to enter the rotating body of the pump, resulting in damage to the hydraulic pump, the present application proposes an integrated filtration system and control method for the pump, a filtration system is arranged outside the main oil circuit of the plunger pump, and the filter element and filter screen of the filter are easy to replace.

[0024] Embodiment 1: This embodiment provides an integrated filter system for a pump, such as Figure 1 As shown, it specifically includes an oil charge pump 11, a variable piston 9 and a plunger pump swash plate 10, and also includes a filter 2, a safety valve 3, an electronic differential pressure valve 4, a controller 5 and a variable control valve 8; The filter 2 , the safety valve 3 , and the electronic differential pressure valve 4 are installed on the filter seat 1 .

[0025] The oil inlet of the filter 2 is connected to the oil outlet of the oil replenishment pump 11, and the oil outlet of the filter 2 is respectively connected to the first port and the second port of the plunger pump; one end of the electronic differential pressure valve 4 is connected to the oil inlet of the filter 2, and the other end is connected to the oil outlet of the filter 2, and is used to detect the pressure difference between the oil inlet and the oil outlet of the filter 2, and transmit the pressure difference to the controller 5; the electronic differential pressure valve 4 is connected to the controller 5 by signal; The inlet of the variable control valve 8 is connected to the oil outlet of the filter 2, the first working oil port is connected to the first chamber of the variable piston 9, the second working oil port is connected to the second chamber of the variable piston 9, and the electromagnets at both ends of the variable control valve 8 are connected to the controller 5 by signal; the plunger pump swash plate 10 is rigidly connected to the variable piston 9; it is used to control the displacement of the variable piston 9 through the variable control valve 8, thereby adjusting the output flow of the plunger pump; The variable control valve 8 is an electric proportional reversing valve and has at least a first working position, a second working position and a middle position; when the variable control valve 8 is in the first working position or the second working position, the hydraulic oil enters the first chamber and the second chamber of the variable piston 9 through the variable control valve 8, thereby driving the plunger pump swash plate 10 to move, so that the output flow of the plunger pump changes; when the variable control valve 8 is in the middle position, no hydraulic oil enters the first chamber and the second chamber of the variable piston 9, the variable piston 9 is in the middle position, and the theoretical output flow of the plunger pump is zero; The controller 5 is configured as follows: Obtaining the pressure difference between the oil inlet and the oil outlet of the filter 2; Comparing the pressure difference with a preset value; the preset value includes a first set value and a second set value, and the first set value is smaller than the second set value; In response to the pressure difference being greater than or equal to a first set value, controlling the alarm module to issue an alarm; In response to the pressure difference being greater than or equal to the second set value, the electromagnets at both ends of the control variable control valve 8 lose power and return to the middle position, so as to drive the plunger pump swash plate to swing back to the zero position, and the theoretical output flow of the plunger pump is zero. In this embodiment, the alarm module adopts a buzzer alarm 7, which is connected to the controller 5 by signal.

[0026] The pump integrated filtration system further includes a filter element life prediction module, which is used to: predict the remaining service life of the filter element according to the pressure difference. In some embodiments, the filter element life prediction module is specifically used to: According to the pressure difference, a filter element life prediction model is used to predict the filter element use time prediction value; wherein the filter element life prediction model stores a linear relationship between the pressure difference between the oil inlet and the oil outlet of the filter and the filter element use time; The remaining service life of the filter element is obtained according to the predicted value of the filter element usage time and the preset total service life of the filter element.

[0027] Furthermore, the pump integrated filtration system also includes a display module connected to the controller 5 for displaying the remaining service life of the filter element. In this embodiment, the display module adopts a central control screen 6, which is convenient for the machine owner to replace the filter element after the last operation.

[0028] The function of the filter 2 is to filter the oil entering the hydraulic pump so that the impurities of the particulate matter are intercepted at the filter screen, thereby protecting the rotor assembly of the plunger pump from damage; it should be noted that in order to prevent component damage caused by pressure buildup when the filter element is blocked, the integrated pump filtering system also includes a safety valve 3, the first end of the safety valve 3 is connected to the oil inlet of the filter 2 (the oil outlet of the replenishing pump 11), the second end of the safety valve 3 is connected to the oil suction port of the replenishing pump 11, and the control end of the safety valve 3 is connected to the oil outlet of the filter 2; when the pressure difference between the oil inlet and the oil outlet of the filter 2 is greater than or equal to the third set value, the safety valve 3 changes from a closed state to an open state, and the oil at the oil inlet of the filter 2 (the oil outlet of the replenishing pump 11) is directly returned to the oil suction port of the replenishing pump 11 through the safety valve 3; wherein the third set value is greater than the second set value. In this embodiment, the safety valve is not only simple in structure, but also can effectively prevent the occurrence of pressure build-up by unloading the oil from the filter inlet to the oil suction port of the oil replenishment pump when the filter element is blocked and the electronic components fail.

[0029] In some embodiments, the first set value is 0.4 MPa, the second set value is 0.5 MPa, and the third set value is 0.6 MPa.

[0030] In this embodiment, the system has three levels of safety protection measures for filter blockage. The first priority is: when the pressure difference at both ends of the filter 2 is ≥0.4MPa, the pressure difference signal is transmitted to the controller 5, and the controller 5 will give a current signal to the buzzer alarm 7, and the buzzer alarm will sound an alarm. At this time, the predicted value of the remaining service life of the filter is also set with the pressure difference = 0.5MPa as the zero boundary point to fix the factory preset remaining service life, prompting the owner of the machine of the expected loss of the filter element; the second priority is: when the pressure difference is ≥0.5MPa, the pressure difference signal is transmitted to the controller. At this time, the controller will control the electromagnets at both ends of a and b of the variable reversing valve 8 to lose power, thereby controlling the plunger pump to be in a zero-position idling state; the third priority is: when the pressure difference is ≥0.6MPa, the safety valve 3 changes from a closed state to an open state under the pressure difference between the left and right chambers, so that the oil pressure at the outlet of the replenishing pump flows directly back to the oil suction port of the replenishing pump to avoid the occurrence of pressure holding.

[0031] In some embodiments, Figure 1 As shown, the variable control valve 8 is a three-position four-way electric proportional reversing valve; When the first end electromagnet a of the variable control valve 8 is energized, the hydraulic oil passes through the first working position (left position) of the variable control valve 8 and enters the first chamber (left chamber) of the variable piston 9. The variable piston 9 moves rightward under the action of the high-pressure oil, pushing the plunger pump swash plate 10 to move from the middle position to the positive direction of maximum displacement. When the electromagnet b at the second end of the variable control valve 8 is energized, the hydraulic oil passes through the second working position (right position) of the variable control valve 8 and enters the second chamber (right chamber) of the variable piston 9. The variable piston 9 moves to the left under the action of the high-pressure oil, pushing the plunger pump swash plate 10 to move from the middle position to the negative maximum displacement direction; When the first end electromagnet a and the second end electromagnet b of the variable control valve 8 are both de-energized, the variable control valve 8 is in the middle position, the variable piston 9 drives the plunger pump swash plate 10 to swing back to the zero position, and the theoretical output flow of the plunger pump is zero. At this time, no matter how fast the pump speed is, the inlet and outlet flow of the plunger pump is always zero. Therefore, when the plunger pump is in the zero state, there is no problem of suction.

[0032] The filter seat 1 is used to connect the entire filter assembly with the hydraulic pump. Through the oil path opened inside the filter seat, the hydraulic oil entering the hydraulic pump from the outside is first passed into the filter assembly for filtration, and then enters the rotor assembly of the hydraulic pump. In some embodiments, the filter seat 1 can have the following structures at the same time, or have one of the two structures: a mounting surface structure that matches the plate-type electronic differential pressure valve, and a mounting hole structure that matches the threaded plug-in electronic differential pressure valve. Or a buzzer alarm is integrated into the filter seat 1.

[0033] In some embodiments, Figure 1 As shown, the oil outlet of the filter 2 is also provided with an oil replenishment relief valve 14, a first relief valve 12 is provided between the oil outlet of the filter 2 and the first port of the plunger pump, and a second relief valve 13 is provided between the oil outlet of the filter 2 and the second port of the plunger pump, the first relief valve 12 and the second relief valve 13 have the same structure and have at least a first working state and a second working state; In the first working state, the first port I of the first relief valve 12 and the second relief valve 13 is unidirectionally connected to the second port II through the one-way valve in the valve, and the hydraulic oil at the oil outlet of the filter 2 is replenished to the low-pressure side of the main oil circuit of the plunger pump through the first relief valve 12 or the second relief valve 13; When the oil pressure on the high-pressure side of the main oil circuit of the plunger pump exceeds the fourth set value, the corresponding first relief valve 12 or the second relief valve 13 is in the second working state, the second port II is connected to the first port I, and the hydraulic oil on the high-pressure side of the main oil circuit is unloaded back to the oil tank through the oil replenishment relief valve 14.

[0034] Since the working oil ports A and B of the closed pump are not connected to the oil tank, the flow loss caused by internal leakage requires the oil replenishment pump 11 to replenish oil to the low-pressure side. At the same time, another part of the oil enters the control variable piston 9 through the variable reversing valve 8 to push the piston movement. The swash plate is rigidly connected to the piston. When the variable piston moves, the swash plate 10 of the plunger pump moves, causing the output flow of the plunger pump to change.

[0035] Embodiment 2: Based on Embodiment 1, this embodiment provides a control method for a pump integrated filtration system, wherein the pump integrated filtration system is any of the above-mentioned pump integrated filtration systems, and the control method comprises: Obtaining the pressure difference between the oil inlet and the oil outlet of the filter 2; Comparing the pressure difference with a preset value; the preset value includes a first set value and a second set value, and the first set value is smaller than the second set value; In response to the pressure difference being greater than or equal to a first set value, controlling the alarm module to issue an alarm; In response to the pressure difference being greater than or equal to the second set value, the electromagnets at both ends of the control variable control valve 8 lose power and return to the middle position, so as to drive the swash plate angle of the plunger pump to return to the zero position, and the theoretical output flow of the plunger pump is zero; The remaining service life of the filter element is predicted based on the pressure difference, and is sent to the display module to display the remaining service life of the filter element.

[0036] In some embodiments, the prediction based on the pressure difference to obtain the remaining service life of the filter element includes: according to the pressure difference, using a filter element life prediction model to predict the filter element service time prediction value; wherein the filter element life prediction model stores the linear relationship between the pressure difference between the oil inlet and the oil outlet of the filter and the filter element service time; The remaining service life of the filter element is obtained according to the predicted value of the filter element usage time and the preset total service life of the filter element.

[0037] In some embodiments, the control method of the integrated filter system for the pump further includes: controlling the working position of the variable control valve 8 according to the output flow requirement of the plunger pump, thereby adjusting the output flow of the plunger pump, and the output flow of the plunger pump supplies oil to the mechanical hydraulic system through the working oil ports A and B.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An integrated filter system for a pump, comprising an oil charge pump, a variable piston and a plunger pump swash plate, characterized in that: It also includes filters, safety valves, electronic differential pressure valves, controllers and variable control valves; The oil inlet of the filter is connected to the oil outlet of the oil replenishment pump, and the oil outlet of the filter is respectively connected to the first port and the second port of the plunger pump; one end of the electronic differential pressure valve is connected to the oil inlet of the filter, and the other end is connected to the oil outlet of the filter, and is used to detect the pressure difference between the oil inlet and the oil outlet of the filter, and upload the pressure difference to the controller; the electronic differential pressure valve is connected to the controller signal; The inlet of the variable control valve is connected to the oil outlet of the filter, the first working oil port is connected to the first chamber of the variable piston, the second working oil port is connected to the second chamber of the variable piston, and the electromagnets at both ends of the variable control valve are connected to the controller signal; the plunger pump swash plate is rigidly connected to the variable piston; and is used to control the displacement of the variable piston through the variable control valve, thereby adjusting the output flow of the plunger pump; The variable control valve is an electric proportional reversing valve and has at least a first working position, a second working position and a middle position; when the variable control valve is in the first working position or the second working position, the hydraulic oil enters the first chamber and the second chamber of the variable piston through the variable control valve, thereby driving the swash plate of the plunger pump to move, so that the output flow of the plunger pump changes; when the variable control valve is in the middle position, no hydraulic oil enters the first chamber and the second chamber of the variable piston, the variable piston is in the middle position, and the theoretical output flow of the plunger pump is zero; The controller is configured to: obtain a pressure difference between an oil inlet and an oil outlet of the filter; compare the pressure difference with a preset value; the preset value includes a first set value and a second set value, and the first set value is less than the second set value; In response to the pressure difference being greater than or equal to a first set value, controlling the alarm module to issue an alarm; In response to the pressure difference being greater than or equal to the second set value, the electromagnets at both ends of the control variable control valve lose power and return to the middle position, driving the swash plate angle of the plunger pump to return to the zero position, and the theoretical output flow of the plunger pump is zero.

2. The integrated filter system for a pump according to claim 1, characterized in that: It also includes a filter element life prediction module, which is used to: predict the remaining service life of the filter element according to the pressure difference to obtain the remaining service life of the filter element.

3. The integrated filter system for a pump according to claim 2, characterized in that: The filter element life prediction module is specifically used for: According to the pressure difference, a filter element life prediction model is used to predict the filter element use time prediction value; wherein the filter element life prediction model stores a linear relationship between the pressure difference between the oil inlet and the oil outlet of the filter and the filter element use time; The remaining service life of the filter element is obtained according to the predicted value of the filter element usage time and the preset total service life of the filter element.

4. The integrated filter system for a pump according to claim 2 or 3, characterized in that: A display module connected to the controller signal is also included to display the remaining service life of the filter element.

5. The integrated filter system for a pump according to claim 1, characterized in that: It also includes a safety valve, wherein a first end of the safety valve is connected to the oil inlet of the filter, a second end of the safety valve is connected to the oil suction port of the oil replenishment pump, and a control end of the safety valve is connected to the oil outlet of the filter; when the pressure difference between the oil inlet and the oil outlet of the filter is greater than or equal to a third set value, the safety valve changes from a closed state to an open state, and the oil at the oil inlet of the filter is directly returned to the oil suction port of the oil replenishment pump through the safety valve; wherein the third set value is greater than the second set value.

6. The pump integrated filtration system according to claim 1, characterized in that: The variable control valve is a three-position four-way electric proportional reversing valve; When the first end electromagnet of the variable control valve is energized, the hydraulic oil enters the first chamber of the variable piston through the first working position of the variable control valve, and the variable piston moves to the right, pushing the swash plate of the plunger pump to move from the middle position to the positive direction of maximum displacement; When the solenoid at the second end of the variable control valve is energized, the hydraulic oil passes through the second working position of the variable control valve and enters the second chamber of the variable piston. The variable piston moves to the left, pushing the swash plate of the plunger pump to move from the middle position to the negative direction of the maximum displacement. When both the first end electromagnet and the second end electromagnet of the variable control valve are not energized, the variable control valve is in the middle position, the variable piston drives the swash plate of the plunger pump to swing back to the zero position, and the theoretical output flow of the plunger pump is zero.

7. The integrated filter system for a pump according to claim 1, characterized in that: The oil outlet of the filter is also provided with an oil replenishment overflow valve, a first overflow valve is provided between the oil outlet of the filter and the first port of the plunger pump, and a second overflow valve is provided between the oil outlet of the filter and the second port of the plunger pump, the first overflow valve and the second overflow valve have the same structure and have at least a first working state and a second working state; In the first working state, the first port of the first relief valve and the second relief valve is unidirectionally connected to the second port through the one-way valve in the valve, and the hydraulic oil at the oil outlet of the filter is replenished to the low-pressure side of the main oil circuit of the plunger pump through the first relief valve or the second relief valve; When the oil pressure on the high-pressure side of the main oil circuit of the plunger pump exceeds the fourth set value, the corresponding first overflow valve or the second overflow valve is in the second working state, the second port is connected to the first port, and the hydraulic oil on the high-pressure side of the main oil circuit is unloaded back to the oil tank through the oil replenishment overflow valve.

8. The pump integrated filtration system according to claim 1, characterized in that: It also includes a filter seat, on which the filter, the safety valve and the electronic differential pressure valve are installed.

9. The pump integrated filtration system according to claim 8, characterized in that: In some embodiments, the filter seat has at least one of the following structures: a mounting surface structure matching with a plate-type electronic differential pressure valve, and a mounting hole structure matching with a threaded plug-in electronic differential pressure valve.

10. A control method for an integrated filter system for a pump, characterized in that: The pump integrated filtration system is the pump integrated filtration system according to any one of claims 1 to 9, and the control method comprises: Obtain the pressure difference between the oil inlet and the oil outlet of the filter; Comparing the pressure difference with a preset value; the preset value includes a first set value and a second set value, and the first set value is smaller than the second set value; In response to the pressure difference being greater than or equal to a first set value, controlling the alarm module to issue an alarm; In response to the pressure difference being greater than or equal to the second set value, the electromagnets at both ends of the control variable control valve lose power and return to the middle position, so as to drive the swash plate angle of the plunger pump to return to the zero position, and the theoretical output flow of the plunger pump is zero; The remaining service life of the filter element is predicted based on the pressure difference, and is sent to the display module to display the remaining service life of the filter element.

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