Closed system speed control loop

Abstract

The invention provides a closed system speed control loop. The closed system speed control loop comprises a closed pump, a load feedback module, a pressure compensation module, an electric proportional reversing valve and a split-flow cooling module. Wherein the closed pump is connected with the load feedback module and the pressure compensation module and used for providing low-pressure small-displacement flow output, the load feedback module is connected with the pressure compensation module and the execution mechanism and used for feeding back the load pressure of the execution mechanism, and the pressure compensation module is connected with the closed pump, the load feedback module and the execution mechanism and used for providing low-pressure small-displacement flow output. The electric proportional directional valve is used for adjusting output flow according to load pressure, is connected with the executing mechanism, and controls flow through the electromagnetic valve to achieve speed control over the executing mechanism.

Description

Technical Field

[0001] The present application relates to the field of underwater hydraulic systems, and in particular to a closed system speed control loop. Background Art

[0002] Due to space and environmental constraints, underwater equipment requires the use of closed pumps to drive hydraulic systems when performing large flow actions. If an open pump is used, a larger oil tank needs to be designed, which is not allowed for some products, and the underwater hydraulic system needs to protect the main control circuit to avoid corrosion and leakage. At present, there are some problems in achieving speed control of multiple groups of execution actions using closed system control oil circuits underwater. When performing compound actions, the inconsistent loads of different actuators will affect the speed of the actuators, resulting in insufficient control accuracy. In addition, the existing system also has room for improvement in energy saving.

[0003] Existing underwater hydraulic systems usually cannot meet the requirements of precise control and energy saving at the same time. In the case of multiple sets of execution actions, it is difficult to achieve precise control of the speed of each actuator due to the unbalanced load. This lack of control accuracy will lead to reduced operating efficiency of underwater equipment and may even affect the normal operation of the equipment. At the same time, traditional hydraulic systems often have high energy consumption, which is not in line with the current development trend of energy conservation and environmental protection.

[0004] In addition, existing underwater hydraulic systems often lack sufficient adaptability when facing complex working environments. For example, at different depths and pressures, the performance of the system may change, affecting the stability and reliability of the control. At the same time, due to the particularity of the underwater environment, the maintenance and troubleshooting of the system also face huge challenges. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides an embodiment, a closed system speed control loop, characterized in that it includes a closed pump, a load feedback module, a pressure compensation module, an electric proportional reversing valve, a shunt cooling module and an action module, and the M2 port of the closed pump is connected to the load feedback module.

[0006] In one embodiment, when the actuator is in the middle position, control pressure is applied to the X1 port of the closed pump, the displacement control mechanism swings, pressure is established in the main oil circuit, and the pressure oil returns to the regulating closed pump through the M2 port and the load feedback module.

[0007] In one embodiment, when the closed pump is started and several actuators are connected to perform compound actions, the relevant electric proportional reversing valve is shifted, and the load pressure after the valve is compared by the shuttle valve to feed back the higher pressure to the external hydraulic control port of the sequence valve of the load feedback module.

[0008] Furthermore, the pressure compensation module includes a pressure reducing valve and a shuttle valve. The shuttle valve is used to compare the load pressures of multiple actuators. The pressure reducing valve ensures that the pressure difference before and after the electric proportional reversing valve is constant. When multiple actuators act simultaneously, the shuttle valve compares the load pressures and feeds back the highest pressure to the load feedback module. At the same time, the pressure reducing valve maintains a constant pressure difference before and after the electric proportional reversing valve.

[0009] Furthermore, the electric proportional reversing valve uses an electric proportional reversing valve to control the action of the actuator, and its output flow rate is only determined by the current size of the solenoid valve. The electric proportional reversing valve works in conjunction with the pressure compensation module. When the actuator is actuated, the electric proportional reversing valve changes position. Since the pressure compensation module ensures that the pressure difference before and after the valve is constant, the output flow rate of the valve only depends on the current size of the solenoid valve.

[0010] Furthermore, the split-flow cooling module includes a one-way valve and an adjustable flow valve for thermal management and flow control of the system.

[0011] Furthermore, the action module includes an action one module, an action two module and an action N module, the action one module is electrically connected to the first valve and the first control element, and the valve and the control element are the first input signal source; the action two module is electrically connected to the second valve and the second control element, and the second valve and the second control element are the second input signal source; the action N module is electrically connected to the third valve and the third control element, and the third valve and the third control element are the third input signal source.

[0012] Furthermore, in the load feedback module, the sequence valve regulates the pressure at port A of the closed pump based on the highest load pressure fed back by the pressure compensation module, so that the pressure is always higher than a small value of the load pressure.

[0013] Furthermore, in the pressure compensation module, when multiple actuators are actuated simultaneously, the shuttle valve compares the load pressures of the actuators and feeds back the highest pressure to the load feedback module.

[0014] Furthermore, the pressure reducing valve is in the pressure compensation module, and during the operation of the system, it maintains a constant pressure difference before and after the electric proportional reversing valve, and cooperates with the electric proportional reversing valve to achieve control.

[0015] The closed system speed control loop provided by the above embodiment has the following beneficial effects:

[0016] The present invention provides a closed system speed control loop, which includes a closed pump, a load feedback module, a pressure compensation module, an electric proportional reversing valve and a shunt cooling module. The closed pump works in coordination with the load feedback module and the pressure compensation module to achieve precise control of the actuator speed. At the same time, energy saving is achieved through low-pressure and small-displacement operation and the shunt cooling module. The system has the advantages of improving control accuracy, achieving energy saving and adapting to complex working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 or the description of the prior art 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 the structures shown in these drawings without paying creative work.

[0018] Figure 1 A closed system speed control loop system block diagram provided for the first embodiment of the present invention;

[0019] Figure 2 A closed pump working frame provided for the first embodiment of the present invention Figure 1 ;

[0020] Figure 3 A closed pump working frame provided for the first embodiment of the present invention Figure 2 ;

[0021] Figure 4 FIG. 1 is a structural diagram of a closed system speed control loop according to the first embodiment of the present invention.

[0022] 1. Pressure reducing valve with external hydraulic control port; 2. Throttle valve 1; 3. Pressure reducing valve; 4. Shuttle valve 1; 5. Shuttle valve 2; 6. Electric proportional reversing valve; 7. Check valve 1; 8. Throttle valve 2; 9. Pressure compensator; 10. Check valve 2; 11. Cooler; 12. Closed pump. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0025] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] Example 1

[0027] refer to Figure 1 In order to solve the above problems, the present invention provides a closed control system speed loop applied to underwater equipment, aiming to solve the speed control problem of multiple sets of execution actions and avoid the influence of the actuator speed due to inconsistent loads. When performing compound actions, the existing technology is often affected by inconsistent loads, which makes it difficult to accurately control the speed of the actuator. Especially in underwater environments, hydraulic systems need efficient and precise control to avoid the adverse effects of space and environmental limitations.

[0028] A closed system speed control loop includes a closed pump, a load feedback module, a pressure compensation module, an electric proportional reversing valve and a shunt cooling module. The closed pump is connected to the load feedback module and the pressure compensation module to provide low-pressure and small-displacement flow, the load feedback module is connected to the pressure compensation module and the actuator to feedback the load pressure of the actuator, the pressure compensation module is connected to the closed pump, the load feedback module and the actuator to adjust the output flow according to the load pressure, the electric proportional reversing valve is connected to the actuator, and the flow is controlled by the solenoid valve to achieve speed control of the actuator.

[0029] The closed pump provides low-pressure and small-displacement flow to ensure stable operation of the system under different load conditions. When the actuator is not moving, the closed pump outputs low-pressure and small-displacement to achieve energy saving, and flushes the internal oil circuit of the closed pump to allow the internal circulation to generate heat. The load feedback module feeds back the load pressure of the actuator in real time to ensure the speed consistency of the actuator under different load conditions. The pressure compensation module adjusts the output flow according to the feedback load pressure to ensure the stability and accuracy of the system when the load changes. The electric proportional reversing valve controls the flow through the solenoid valve to achieve precise control of the actuator speed. The shunt cooling module ensures temperature control of the system when working under high load to prevent overheating of key components.

[0030] The main features of the speed loop of the closed control system include: the closed pump provides low-pressure and small-displacement flow to ensure stable operation of the system under different load conditions. When the actuator is not in action, the closed pump outputs low-pressure and small-displacement to achieve energy saving, and flushes the internal oil circuit of the closed pump to allow the internal circulation to generate heat. The load feedback module provides real-time feedback on the load pressure of the actuator to ensure the speed consistency of the actuator under different load conditions. The pressure compensation module adjusts the output flow according to the feedback load pressure to ensure the stability and accuracy of the system when the load changes. The electric proportional reversing valve controls the flow through the solenoid valve to achieve precise control of the actuator speed. The shunt cooling module ensures temperature control of the system when working under high load to prevent overheating of key components.

[0031] In the prior art, the speed control of multiple groups of execution actions is often affected by inconsistent loads, making it difficult to accurately control the speed of the actuator. The present invention achieves accurate control of the actuator speed through the coordinated work of a closed pump, a load feedback module, a pressure compensation module and an electric proportional reversing valve, thus solving this technical problem.

[0032] For example, in underwater equipment, the closed pump provides low-pressure and small-displacement flow, the load feedback module feeds back the load pressure of the actuator in real time, the pressure compensation module adjusts the output flow according to the fed-back load pressure, and the electric proportional reversing valve controls the flow through the solenoid valve to achieve precise control of the actuator speed. The split cooling module ensures temperature control of the system when working under high load to prevent overheating of key components.

[0033] Through the above technical solution, the present invention effectively solves the speed control problem of multiple groups of execution actions, avoids the situation where the speed of the actuator is affected by inconsistent loads, and has a high energy-saving effect.

[0034] Through the setting of the above-mentioned load feedback module, the present application can realize real-time monitoring of the load pressure of each actuator and feed back the highest load pressure to the pressure compensation module. Compared with the prior art, the present application realizes precise control of the flow rate through the coordinated work of the load feedback module and the pressure compensation module, ensures the stable operation of the system under different load conditions, and further improves the reliability and work efficiency of the system.

[0035] Furthermore, the present application also proposes that a shuttle valve is provided in the pressure compensation module, and the shuttle valve is connected to different actuators and load feedback modules, so as to compare the load pressures of different actuators and transmit the highest pressure to the load feedback module through a feedback loop, so as to adjust the oil flow of each actuator.

[0036] The shuttle valve in the pressure compensation module is used to compare the load pressures of different actuators and feed back the highest pressure to the load feedback module. In this way, the system can adjust the oil flow of each actuator according to the highest load pressure, thereby achieving precise control of different actuators. The design of the shuttle valve enables the system to dynamically respond to the load changes of different actuators, ensuring that each actuator can obtain appropriate flow supply when the load changes, thereby solving the problem that the system cannot accurately adjust the oil flow of each actuator when the load pressure of different actuators is inconsistent. The design of the shuttle valve can be varied. For example, a hydraulically controlled shuttle valve can be used, which has a simple structure and fast response and is suitable for most hydraulic systems. Another implementation method is to use an electronically controlled shuttle valve to control the switching of the shuttle valve through an electrical signal to achieve higher control accuracy. In addition, the shuttle valve can be integrated with a pressure sensor, and the load pressure of different actuators can be monitored in real time through the sensor, and the state of the shuttle valve can be adjusted through an electronic control system to achieve more accurate flow regulation. Through the above design, the problem that the system cannot accurately adjust the oil flow of each actuator when the load pressure of different actuators is inconsistent can be effectively solved. Compared with the prior art, the advantage of the present application is that it can dynamically respond to the load changes of different actuators, ensuring that each actuator can obtain appropriate flow supply when the load changes, thereby achieving precise control of different actuators. This design not only improves the control accuracy of the system, but also enhances the stability and reliability of the system.

[0037] refer to Figure 2 When the closed pump is started and all actuators are in the middle position without action, a control pressure is given to the X1 port of the closed pump 12, and the displacement control mechanism of the closed pump begins to swing, and pressure is established in the main oil circuit. At this time, the pressure oil passes through the M2 port of the closed pump 12, through the 2 throttle valve, and the 3 pressure reducing valve and returns to the closed pump, forming a dynamic balance with the displacement control mechanism. At this time, the closed pump will operate in a low-pressure and small-displacement state, and the flow of the main oil circuit is only for the internal leakage of the closed pump, which plays a role in cleaning and flushing the leakage oil cavity in the pump.

[0038] Furthermore, the present application also proposes that the electric proportional reversing valve controls the flow rate through the solenoid valve, the solenoid valve is connected to the actuator, and the current size is proportional to the output flow rate, thereby controlling the movement speed of each actuator. The electric proportional reversing valve controls the flow rate through the solenoid valve, the solenoid valve is connected to the actuator, and the current size is proportional to the output flow rate, thereby controlling the movement speed of each actuator. The function of the solenoid valve is to adjust the flow rate according to the input current size, thereby achieving precise control of the actuator speed. This design can accurately control the movement speed of each actuator in the hydraulic system by adjusting the current, ensuring that each actuator can run at the expected speed under different load conditions. As a preferred embodiment, the solenoid valve can achieve precise flow regulation through proportional control technology. Specifically, the solenoid valve receives the current signal from the controller, adjusts the position of the valve core according to the current size, thereby controlling the flow size. Further, a flow sensor can be set between the solenoid valve and the actuator to monitor the flow rate in real time, and feed back the monitoring results to the controller to achieve closed-loop control. As a result, the system can perform adaptive adjustment according to actual conditions to improve control accuracy and response speed. Compared with the prior art, the technical solution of the present application realizes precise control of the actuator speed by controlling the flow rate through the solenoid valve. By adjusting the current, the movement speed of each actuator in the hydraulic system can be accurately controlled to ensure that each actuator can run at the expected speed under different load conditions. This solution not only improves the control accuracy of the system, but also simplifies the system structure, reduces costs, and has high practical value.

[0039] refer to Figure 3 , when the closed pump is started, the actuator has several links to perform compound actions; at this time, under the premise of a state, assuming that action one and action two are performed simultaneously, the relevant electric proportional reversing valve 6 is switched (whether left or right), and the load pressure behind the valve of the electric proportional reversing valve 6 will compare the load pressures of the two-link action through the 3, 5 shuttle valves and feedback the higher pressure to the external hydraulic control port of the 1 sequence valve of the load feedback module. At this time, the sequence valve 1 will ensure that the pressure at the A port of the closed pump is always higher than a very small value of the load pressure. At the same time, the 3 pressure reducing valve will ensure that the pressure difference before and after the electric proportional reversing valve 6 is constant. At this time, the output flow of the electric proportional reversing valve is only determined by the current of the solenoid valve, so as to ensure that each link action is not affected by the load. At the same time, the output flow of the closed pump is mainly based on the actuator with the highest load among all actions, so as to achieve the purpose of energy saving and speed control.

[0040] Furthermore, the present application also proposes that the system integrates control components into the valve box through modular design.

[0041] By integrating the control components into the valve box, the structural design of the system can be simplified and the compactness and reliability of the system can be improved. Modular design helps to reduce the difficulty of installation and maintenance of the system, and can also improve the scalability of the system. The integration of various control components can also effectively reduce pipeline connections, reduce the risk of leakage, and improve the overall efficiency of the system. The integration of control components can be achieved in a variety of ways. For example, standardized control modules can be used, and these modules can be combined and replaced as needed to achieve different functions. Specifically, control components such as closed pumps, load feedback modules, pressure compensation modules, electric proportional reversing valves, and shunt cooling modules can be integrated in the valve box. Through reasonable layout and design, it is possible to ensure that the connection between each module is compact and reliable, reduce the length and number of pipelines, and thus reduce the risk of leakage. Further, high-performance sealing materials and advanced processing technology can be used to ensure the sealing performance of each connection part, further reducing the possibility of leakage. The present application simplifies the structural design of the system by integrating the control components into the valve box, and improves the compactness and reliability of the system. Compared with the prior art, the present application reduces pipeline connections, reduces the risk of leakage, and improves the overall efficiency of the system. The modular design also reduces the difficulty of installation and maintenance of the system and improves the scalability of the system. In general, the present application provides a more efficient and reliable closed control system speed loop.

[0042] Furthermore, the present application also proposes that the system integrates the control components into the valve box through modular design. By integrating the control components into the valve box through modular design, the system structure can be effectively optimized, the system can be made more compact, the space occupied can be reduced, and the reliability of the system can be improved. The modular design enables the various control components to work together better, reduces the complexity of the connection between the components, and reduces the failure rate. Specifically, by integrating the control components into the valve box, the use of external pipelines can be reduced, the risk of leakage can be reduced, and the maintenance and repair process can be simplified. As a result, the overall performance and reliability of the system can be greatly improved, and the control components can be designed and manufactured using standardized modules, which can not only simplify the production process, but also facilitate subsequent upgrades and replacements. For example, key components such as electric proportional reversing valves and pressure compensation modules can be designed as standardized modules and directly installed in the valve box. Furthermore, the interior of the valve box can be designed as a multi-layer structure, and the layers are connected through built-in oil circuits to reduce the use of external connection pipelines. At the same time, the material of the valve box can be selected from high-strength, corrosion-resistant alloy materials to meet the needs of the underwater environment. The system of the present application can integrate the control components into the valve box through modular design in the closed control system speed loop, optimize the system structure, and improve the compactness and reliability of the system. Compared with the existing technology, the system of the present application has significant advantages in reducing the occupied space, reducing the complexity of the connection, reducing the failure rate, and improving the convenience of maintenance. Therefore, the technical solution of the present application is of great significance in improving the performance and reliability of the system.

[0043] Furthermore, the present application also proposes that the shunt cooling module is connected to key components such as pumps and valve groups, and is used to reduce the temperature during the operation of the system. By circulating the coolant, it is ensured that key components such as pumps and valve groups will not overheat when working at high loads. The shunt cooling module is connected to key components such as pumps and valve groups, and is used to reduce the temperature during the operation of the system. By circulating the coolant, it is ensured that key components such as pumps and valve groups will not overheat when working at high loads. The shunt cooling module is connected to key components and uses the flow of circulating coolant to effectively dissipate heat and prevent overheating, thereby ensuring the stable operation of the system and the life of key components. The implementation methods of the shunt cooling module may include but are not limited to the following: First, the shunt cooling module may adopt a built-in cooling circuit, and the coolant is introduced into the cooling module through a pump for circulating cooling; secondly, the shunt cooling module may be provided with multiple coolant inlets and outlets to increase the flow path of the coolant and improve the cooling efficiency; in addition, the shunt cooling module may also be designed with a temperature control device, and the flow and temperature of the coolant are automatically adjusted by monitoring the temperature of key components to achieve a more accurate temperature control effect. By adopting the shunt cooling module, the present application effectively solves the problem of over-high temperature during system operation, ensures the normal operation of key components such as pumps and valve groups when working under high load, prolongs the service life of key components, and improves the stability and reliability of the system. Compared with the prior art, the present application significantly improves the heat dissipation efficiency of the system by introducing the shunt cooling module, avoiding system failure and performance degradation caused by overheating.

[0044] Further, the present application also proposes that the closed pump system is connected to each actuator by linkage with an external load feedback module and a pressure compensation module, and adjusts the oil flow according to the load change of each actuator. The closed pump system is connected to each actuator by linkage with an external load feedback module and a pressure compensation module. The load feedback module monitors the load pressure of each actuator in real time and feeds back the highest load pressure to the pressure compensation module. The pressure compensation module adjusts the output flow of the closed pump according to the fed-back load pressure, thereby accurately adjusting the oil flow. In this way, the system can dynamically adjust the oil flow according to the load change of each actuator, ensure the stable operation of each actuator under different load conditions, and avoid the problem of actuator speed change caused by inconsistent load. The closed pump system monitors the load pressure of each actuator in real time through the load feedback module, and feeds back the highest load pressure to the pressure compensation module. The pressure compensation module adjusts the output flow of the closed pump according to the fed-back load pressure. Further, the load feedback module may include one or more load pressure sensors, which are connected to each actuator to monitor the load pressure of each actuator in real time. A shuttle valve is provided in the pressure compensation module, and the shuttle valve is connected to different actuators and load feedback modules, and is used to compare the load pressures of different actuators, and transmit the highest pressure to the load feedback module through a feedback loop. In this way, the oil flow rate can be adjusted more accurately to ensure the stable operation of each actuator under different load conditions. Through the linkage of the closed pump system with the external load feedback module and the pressure compensation module, the function of adjusting the oil flow rate according to the load changes of each actuator is realized. Compared with the prior art, the present application can dynamically adjust the oil flow rate, ensure the stable operation of each actuator under different load conditions, avoid the problem of actuator speed changes caused by inconsistent loads, and improve the control accuracy and stability of the system. In addition, by real-time monitoring and feedback of the highest load pressure, the response speed and control effect of the system are further improved.

[0045] Furthermore, the present application also proposes that the system adopts a highly integrated modular structure, and the output flow of the closed pump is based on the actuator with the highest load, and precise control is achieved by controlling the flow. The highly integrated modular structure plays an important role in solving the problem of precise speed control of multiple groups of execution actions in underwater environments. This structure uses the output flow of the closed pump as a reference to the actuator with the highest load, ensuring that the speed of the actuator can be accurately controlled even when the load is inconsistent. This design not only improves the accuracy of speed control, but also has a high energy-saving effect, and is suitable for use in underwater equipment with limited space and environment. By controlling the flow, the influence of inconsistent loads on the speed of the actuator during compound actions is effectively avoided, thereby achieving more precise control of the speed of multiple groups of execution actions.

[0046] The closed pump system is connected to each actuator through linkage with the external load feedback module and the pressure compensation module, and adjusts the oil flow according to the load change of each actuator. The load feedback module includes a load pressure sensor, which is connected to each actuator to monitor the load pressure of each actuator in real time, and is connected to the pressure compensation module to feed back the highest load pressure to the pressure compensation module. A shuttle valve is provided in the pressure compensation module, which is connected to different actuators and load feedback modules to compare the load pressures of different actuators and transmit the highest pressure to the load feedback module through the feedback loop to adjust the oil flow of each actuator. The electric proportional reversing valve controls the flow through the solenoid valve, which is connected to the actuator. The current size of the solenoid valve is proportional to the output flow, thereby controlling the movement speed of each actuator. The system integrates the control components into the valve box through modular design.

[0047] Therefore, based on the existing technology, this application solves the problem of precise speed control of multiple groups of execution actions in underwater environments by adopting a highly integrated modular structure and output flow control technology of a closed pump. Compared with the existing technology, this application has a higher energy-saving effect while achieving precise control, and is suitable for use in underwater equipment with limited space and environment. By controlling the flow, the influence of inconsistent loads on the speed of the actuator during compound actions is effectively avoided, thereby achieving more precise control of the speed of multiple groups of execution actions.

[0048] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A closed system speed control loop, characterized in that: It comprises a closed pump, a load feedback module, a pressure compensation module, an electric proportional reversing valve, a shunt cooling module and an action module. The M2 port of the closed pump is connected to the load feedback module.

2. The closed system speed control loop according to claim 1, characterized in that: When the actuator is in the middle position, control pressure is applied to the X1 port of the closed pump, the displacement control mechanism swings, pressure is established in the main oil circuit, and the pressure oil returns to the regulating closed pump through the M2 port and the load feedback module.

3. The closed system speed control loop according to claim 1, characterized in that: When the closed pump is started and several actuators are connected to perform compound actions, the relevant electric proportional reversing valve is shifted, and the load pressure after the valve is compared by the shuttle valve and the higher pressure is fed back to the external hydraulic control port of the sequence valve of the load feedback module.

4. The closed system speed control loop according to claim 1, characterized in that: The pressure compensation module includes a pressure reducing valve and a shuttle valve. The shuttle valve is used to compare the load pressure of the actuator. The pressure reducing valve ensures that the pressure difference before and after the electric proportional reversing valve is constant. When the actuators act simultaneously, the shuttle valve compares the load pressures and feeds back the highest pressure to the load feedback module.

5. The closed system speed control loop according to claim 1, characterized in that: The electric proportional reversing valve controls the action of the actuator according to the electric proportional reversing valve, and its output flow is only determined by the current of the solenoid valve. The electric proportional reversing valve works in conjunction with the pressure compensation module. When the actuator acts, the electric proportional reversing valve changes position.

6. The closed system speed control loop according to claim 1, characterized in that: The split flow cooling module includes a one-way valve and an adjustable flow valve.

7. The closed system speed control loop according to claim 1, characterized in that: The action module includes an action one module, an action two module and an action N module. The action module 1 is electrically connected to the first valve and the first control element, and the valve and the control element are the first input signal sources; The action second module is electrically connected to the second valve and the second control element, and the second valve and the second control element are second input signal sources; The action N module is electrically connected to a third valve and a third control element, and the third valve and the third control element are third input signal sources.

8. The closed system speed control loop according to claim 3, characterized in that: In the load feedback module, the sequence valve regulates the pressure of the closed pump A port based on the highest load pressure fed back by the pressure compensation module.

9. The closed system speed control loop according to claim 4, characterized in that: The shuttle valve compares the load pressure of the actuator in the pressure compensation module and feeds back the highest pressure to the load feedback module.

10. The closed system speed control loop according to claim 4, characterized in that: The pressure reducing valve is in the pressure compensation module, and during the operation of the system, it maintains a constant pressure difference before and after the electric proportional reversing valve, and cooperates with the control of the electric proportional reversing valve.

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