Servo motor hydraulic flow combining system

Abstract

This invention discloses a servo motor hydraulic confluence system, including an oil tank, an energy unit, a control unit, and main and auxiliary oil circuits. The energy unit includes a main energy unit and an auxiliary energy unit. The main energy unit includes a main servo motor and a main fixed displacement pump, and the auxiliary energy unit includes an auxiliary servo motor and an auxiliary fixed displacement pump. The control unit includes a directional valve, a cartridge valve, and a shuttle valve. The main oil circuit is connected to the first working port of the cartridge valve and the first inlet port of the shuttle valve, and is also connected to the outlet port of the main fixed displacement pump. The auxiliary oil circuit is connected to the second working port of the cartridge valve and the inlet port of the directional valve, and is also connected to the outlet port of the auxiliary fixed displacement pump. The control port of the cartridge valve is connected to the outlet port of the shuttle valve. The first working port of the directional valve is connected to the second inlet port of the shuttle valve. The return port of the directional valve is connected to the oil tank. The advantage is that it can prevent the auxiliary pump from being reversed by impact during confluence and can also achieve reverse pressure relief after independent operation.

Description

Technical Field

[0001] This invention relates to a hydraulic confluence system, and more particularly to a servo motor hydraulic confluence system. Background Technology

[0002] In hydraulically driven equipment such as injection molding machines and die-casting machines, dual-pump or multi-pump confluence technology is often used to meet the demands of high-speed, high-pressure, and high-flow operating conditions. Servo motor hydraulic confluence systems have become the mainstream technology in current hydraulic drive equipment due to their fast response, high control precision, and significant energy-saving effects.

[0003] A typical structure of a traditional servo motor hydraulic confluence system is as follows: Figure 1 As shown, it mainly consists of a main energy unit C1, a secondary energy unit C2, a control unit C3, and an oil tank C4. The main energy unit C1 includes a main servo driver C11, a main servo motor C10, and a main fixed displacement pump C9, all connected in sequence. The secondary energy unit C2 includes a secondary servo driver C14, a secondary servo motor C13, and a secondary fixed displacement pump C12, all connected in sequence. The control unit C3 includes a confluence valve C15 and a check valve C16.

[0004] The working modes of the above-mentioned traditional system are as follows: 1. Main and auxiliary fixed displacement pumps working in tandem: When the system requires a large flow rate, the main driver C11 drives the main servo motor C10 to drive the main fixed displacement pump C9 to rotate forward. At the same time, it outputs a signal to the auxiliary driver C14, causing the auxiliary servo motor C13 to drive the auxiliary fixed displacement pump C12 to rotate forward synchronously. The merging valve C15 is energized and switched. The hydraulic oil from the main fixed displacement pump C9 and the auxiliary fixed displacement pump C12 is supplied to the main oil circuit C17 or the auxiliary oil circuit C18 after merging through the merging valve C15. The check valve C16 located at the outlet of the auxiliary fixed displacement pump C12 is used to prevent the high pressure oil impact of the main fixed displacement pump C9 from causing the auxiliary fixed displacement pump C12 to reverse. 2. Auxiliary fixed displacement pump working independently: When only a small flow rate is required, the auxiliary driver C14 drives the auxiliary servo motor C13 to drive the auxiliary fixed displacement pump C12 to rotate forward. The merging valve C15 is not energized. The hydraulic oil is supplied to the auxiliary oil circuit C18 only through the check valve C16.

[0005] The aforementioned traditional system has the following drawbacks in practical applications: After the auxiliary oil circuit C18 finishes operating independently, the auxiliary fixed displacement pump C12 cannot depressurize by reversing due to the presence of the check valve C16. This results in high-pressure oil remaining in the pipeline between the auxiliary oil circuit C18 and the check valve C16. When the auxiliary oil circuit C18 performs its next operation, the residual pressure is released instantaneously, generating a severe pressure shock and abnormal noise. This not only affects the user experience of the equipment but also damages hydraulic components and reduces the system's lifespan over time. To solve this problem, the conventional approach in the field is to directly eliminate the check valve C16 at the outlet of the auxiliary fixed displacement pump, allowing the auxiliary fixed displacement pump to reverse and depressurize after independent operation. However, this improvement introduces new problems: When the main and auxiliary fixed displacement pumps are combined under heavy load conditions, the high-pressure oil output from the main fixed displacement pump C9 directly impacts the auxiliary fixed displacement pump C12 due to the loss of the protection of the check valve C16. This causes the auxiliary fixed displacement pump C12 to reverse abnormally, resulting in system pressure fluctuations, reduced merging efficiency, and even damage to the auxiliary fixed displacement pump. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a servo motor hydraulic merging system that can both prevent the auxiliary pump from being reversed by impact during merging and achieve reverse depressurization after independent operation.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A servo motor hydraulic confluence system includes an oil tank, an energy unit, a control unit, and a main oil circuit and a secondary oil circuit. The energy unit includes a main energy unit and a secondary energy unit. The main energy unit includes a main servo motor and a main fixed displacement pump. The secondary energy unit includes a secondary servo motor and a secondary fixed displacement pump. The oil inlets of both the main and secondary fixed displacement pumps are connected to the oil tank. The system is characterized by: The control unit includes a directional valve, a cartridge valve, and a shuttle valve; The main oil circuit is connected to the first working oil port of the cartridge valve and the first oil inlet of the shuttle valve, and the main oil circuit is connected to the oil outlet of the main metering pump. The auxiliary oil circuit is connected to the second working oil port of the cartridge valve and the oil inlet of the reversing valve, and the auxiliary oil circuit is connected to the oil outlet of the auxiliary metering pump. The control port of the cartridge valve is connected to the outlet port of the shuttle valve; The first working port of the reversing valve is connected to the second inlet port of the shuttle valve; The return port of the reversing valve is connected to the oil tank.

[0008] The main power unit also includes a main servo driver, which is electrically connected to the main servo motor and is used to control the main servo motor to rotate forward or in reverse. The secondary power unit also includes a secondary servo driver, which is electrically connected to the secondary servo motor and is used to control the secondary servo motor to rotate forward or in reverse.

[0009] An oil suction filter is provided between the oil inlet of the main metering pump and the auxiliary metering pump and the oil tank. The first port of the oil suction filter is connected to the oil inlet of the corresponding metering pump, and the second port of the oil suction filter is connected to the oil tank.

[0010] Pressure sensors are installed at the oil outlets of both the main metering pump and the auxiliary metering pump, and the pressure sensors are electrically connected to the corresponding main servo driver and auxiliary servo driver.

[0011] The aforementioned directional valve is a two-position four-way solenoid directional valve.

[0012] The shuttle valve is a valve with a logic OR function, used to select the higher pressure of the first oil inlet and the second oil inlet to output to the oil outlet.

[0013] The cartridge valve is a two-way logic cartridge valve.

[0014] Compared with the prior art, the advantages of the present invention are as follows: (1) Combining shock protection and pressure relief functions: Through the coordinated operation of the reversing valve, cartridge valve and shuttle valve, when the main and auxiliary quantitative pumps are working together, the cartridge valve can automatically open and close according to the oil circuit pressure, effectively preventing the reverse rotation of the auxiliary quantitative pump caused by the impact of the high pressure oil of the main quantitative pump; after the auxiliary quantitative pump finishes working independently, the auxiliary quantitative pump can freely reverse to relieve pressure, so as to eliminate the impact and abnormal noise caused by the residual pressure in the pipeline; (2) Simple structure and controllable cost: Based on the traditional structure, only the reversing valve and shuttle valve are added, and the confluence valve is replaced with a cartridge valve, which can achieve a comprehensive improvement in function with a small increase in cost and high cost performance; (3) Flexible control and high level of intelligence: The system can automatically switch between merging and independent working modes according to the working conditions, without the need for complex logic control; the pressure adaptive characteristics of the cartridge valve ensure timely response and reliable protection; it can be used with pressure sensors to realize closed-loop control, further improving control accuracy; (4) Improve system reliability and lifespan: Eliminate the risk of pressure shock and abnormal reverse rotation of the auxiliary fixed pump, reduce fatigue damage to hydraulic components, significantly extend the service life of the system, and reduce maintenance costs; (5) Wide range of applications: It does not depend on a specific pump type or control method and can be widely used in various hydraulic equipment that require dual pump confluence, such as injection molding machines, die casting machines, and hydraulic presses. It has good versatility and adaptability. Attached Figure Description

[0015] Figure 1 A hydraulic schematic diagram of a traditional servo motor hydraulic confluence system; Figure 2 This is a hydraulic schematic diagram of the directional valve in the non-electrical state in this invention; Figure 3 This is a hydraulic schematic diagram of the directional valve in the energized state in this invention. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0017] As shown in the figure, a servo motor hydraulic confluence system includes an oil tank 4, an energy unit, a control unit 3, a main oil circuit 9, and an auxiliary oil circuit 10.

[0018] In this specific embodiment, the energy unit includes a main energy unit 1 and a secondary energy unit 2, wherein: The main energy unit 1 includes a main servo driver 101, a main servo motor 102, and a main metering pump 103. The main servo driver 101 is electrically connected to the main servo motor 102 and is used to control the main servo motor 102 to rotate forward or backward. The output shaft of the main servo motor 102 is connected to the drive shaft of the main metering pump 103 for driving the main metering pump 103 to work. The secondary energy unit 2 includes a secondary servo driver 201, a secondary servo motor 202, and a secondary metering pump 203. The secondary servo driver 201 is electrically connected to the secondary servo motor 202 and is used to control the secondary servo motor 202 to rotate forward or backward. The output shaft of the secondary servo motor 202 is connected to the drive shaft of the secondary metering pump 203 for driving the secondary metering pump 203 to work.

[0019] In this specific embodiment, the oil inlets of both the main fixed displacement pump 103 and the auxiliary fixed displacement pump 203 are connected to the oil tank 4. An oil suction filter 5 is installed between the oil inlet of the main fixed displacement pump 103 and the oil tank 4, and an oil suction filter 6 is installed between the oil inlet of the auxiliary fixed displacement pump 203 and the oil tank 4. The first port of the oil suction filter (5, 6) is connected to the oil inlet of the corresponding fixed displacement pump, and the second port is connected to the oil tank 4. These filters are used to remove contaminants from the hydraulic oil in the oil tank 4, thereby protecting the fixed displacement pumps.

[0020] In this specific embodiment, a main pressure sensor 7 is installed at the oil outlet of the main fixed displacement pump 103, and a secondary pressure sensor 8 is installed at the oil outlet of the secondary fixed displacement pump 203. The main pressure sensor 7 is electrically connected to the main servo driver 101, and the secondary pressure sensor 8 is electrically connected to the secondary servo driver 201. They are used to collect the working pressure of the main oil circuit 9 and the secondary oil circuit 10 in real time, and feed the pressure signal back to the corresponding servo driver to realize closed-loop pressure control.

[0021] In this specific embodiment, the control unit includes a reversing valve 301, a cartridge valve 303, and a shuttle valve 302, wherein: The reversing valve 301 is a two-position four-way solenoid reversing valve, with an inlet port P, a first working port A1, a second working port B1 (B1 is closed), and a return port T. When the solenoid of the reversing valve 301 is de-energized (e.g., when...), the valve will automatically de-energize. Figure 2 As shown), port P is connected to port A1, and port B1 is connected to port T; when the electromagnet of the reversing valve 301 is energized (as shown), Figure 3 As shown in the figure, port P is connected to port B1, and port A1 is connected to port T; Cartridge valve 303 is a two-way logic cartridge valve, having a first working port B2, a second working port A2, and a control port X. When there is no pressure or low pressure at control port X, cartridge valve 303 opens under the action of the pressure difference between the inlet and outlet ports; when high-pressure oil is introduced into control port X, cartridge valve 303 closes. The shuttle valve 302 is a valve with a logic OR function, having a first inlet 3021, a second inlet 3022, and an outlet 3023. The shuttle valve 302 is used to select the higher pressure between the first inlet 3021 and the second inlet 3022 and output it from the outlet 3023.

[0022] The specific oil circuit connections are as follows: The main oil circuit 9 is connected to the first working oil port B2 of the cartridge valve 303 and the first oil inlet 3021 of the shuttle valve 302, and the main oil circuit 9 is connected to the oil outlet of the main fixed displacement pump 103. The auxiliary oil passage 10 is connected to the second working oil port A2 of the cartridge valve 303 and the oil inlet port P of the directional valve 301, respectively, and the auxiliary oil passage 10 is connected to the oil outlet of the auxiliary fixed displacement pump 203. The control port X of the cartridge valve 303 is connected to the outlet port 3023 of the shuttle valve 302; The first working oil port A1 of the reversing valve 301 is connected to the second oil inlet 3022 of the shuttle valve 302; The return port T of the reversing valve 301 is connected to the oil tank 4.

[0023] Based on the specific structure of this system, it has four operating modes: main and auxiliary pump combined operation mode, main pump independent operation mode, auxiliary pump independent operation mode, and main and auxiliary pump synchronous independent operation mode. The following section combines... Figure 2 and Figure 3 A detailed explanation of the working principles of each mode is provided: (1) Main and auxiliary pump combined operation mode When the system requires a large flow rate (such as during the injection stage of an injection molding machine), the host computer of the device using this system (not shown in the figure) outputs a flow merging command. After receiving the command, the main servo driver 101 controls the main servo motor 102 to rotate forward, driving the main fixed pump 103 to draw oil from the oil tank 4 through the suction filter 5. The hydraulic oil is pressurized by the main fixed pump 103 and then output to the main oil circuit 9. At the same time, the main servo driver 101 sends the synchronization command to the auxiliary servo driver 201. The auxiliary servo driver 201 controls the auxiliary servo motor 202 to rotate forward, driving the auxiliary fixed pump 203 to draw oil from the oil tank 4 through the suction filter 6. The hydraulic oil is pressurized by the auxiliary fixed pump 203 and output to the auxiliary oil circuit 10. At this time, the host computer outputs a signal to energize the electromagnet of the reversing valve 301, and the reversing valve 301 switches to the left position (e.g., Figure 3 (As shown in the figure), its P port is connected to B1 port (closed), and its A1 port is connected to T port (return to oil tank). The pressure oil of the auxiliary oil circuit 10 goes through the P port of the reversing valve 301 to the B1 port where it is closed, and goes directly to the A2 port of the cartridge valve. Because the first inlet 3021 of the shuttle valve 302 is connected to the pressure oil of the main oil circuit 9, and the second inlet 3022 is connected to the A1 port and T port of the directional valve 301 to return to the oil tank, the valve core of the shuttle valve 302 is switched to the right side, the 3022 port is sealed, and the 3021 port and 3023 port are connected to the control port X of the cartridge valve 303. According to the characteristics of the cartridge valve 303, when the oil pressure of the auxiliary oil circuit 10 is slightly greater than that of the main oil circuit 9, the hydraulic pressure overcomes the spring force of the valve core of the cartridge valve 303, and the oil enters through the A2 port of the cartridge valve 303 and opens the valve core of the cartridge valve 303. The A2 and B2 ports are connected, and the oil in the auxiliary oil circuit 10 and the oil in the main oil circuit 9 are merged.

[0024] Merging process analysis: Normal merging operation: The auxiliary fixed displacement pump 203 rotates forward following the main fixed displacement pump 103. At this time, the valve core of the shuttle valve 302 is switched to the right position by the oil pressure of the main pump. The cartridge valve 303 opens (or remains open) under the action of the pressure difference between the inlet and outlet oil ports. The hydraulic oil of the main oil circuit 9 and the auxiliary oil circuit 10 enters from the second working oil port A2 and the first working oil port B2 of the cartridge valve 303, respectively. After merging inside the cartridge valve 303, it flows out through the cartridge valve 303 (in fact, the cartridge valve 303 is a two-way valve. The oil after merging can flow out from either port to supply the load. The specific flow direction depends on the load position). The high-pressure oil after merging is supplied to the actuator connected to the main oil circuit 9 or the auxiliary oil circuit 10 (not shown in the figure).

[0025] Pressure fluctuation condition: If the pressure of the main oil circuit 9 is momentarily higher than that of the auxiliary oil circuit 10 due to load fluctuation, the high-pressure oil of the main oil circuit 9 enters the control port X of the cartridge valve 303 through the first inlet 3021 and outlet 3023 of the shuttle valve 302. The cartridge valve 303 closes quickly under the action of the high-pressure oil at the control port X, cutting off the connection between the main oil circuit 9 and the auxiliary oil circuit 10, thereby preventing the high-pressure oil of the main oil circuit 9 from impacting the auxiliary metering pump 203 and causing it to reverse. When the pressure of the main oil circuit 9 returns to normal, the cartridge valve 303 reopens under the action of the pressure difference between the inlet and outlet, restoring the confluence.

[0026] Since the auxiliary metering pump 203 operates in the forward direction following the main metering pump 103, there is no risk of the main metering pump 103 being reversed by the auxiliary metering pump 203. This two-way protection mechanism ensures that the pressure can be adjusted in time regardless of which circuit is too high, protecting the safety of the pump set.

[0027] When the merging operation ends, the host computer outputs a stop command. The main servo driver 101 controls the main servo motor 102 to reverse and release pressure based on the pressure signal fed back by the main pressure sensor 7. At the same time, the main servo driver 101 sends a command to the auxiliary servo driver 201 to control the auxiliary servo motor 202 to synchronously reverse and release pressure until the pressure detected by the main pressure sensor 7 and the auxiliary pressure sensor 8 is zero or close to zero. The residual pressure in the main oil circuit 9 and the auxiliary oil circuit 10 is discharged back to the oil tank 4 through the reverse rotation of the main metering pump 103 and the auxiliary metering pump 203, completely eliminating the residual pressure in the pipeline.

[0028] (2) Main pump independent working mode When the system requires only a small flow rate and is supplied with oil solely by the main pump (such as during the mold opening and closing phase of an injection molding machine), the host computer outputs an independent working command for the main pump. The main servo driver 101 controls the main servo motor 102 to rotate forward, driving the main fixed pump 103 to draw oil from the oil tank 4 and output hydraulic oil to the main oil circuit 9. At this time, the reversing valve 301 is not energized and is in the right position ( Figure 2As shown), its P port is connected to its A1 port. The auxiliary servo drive 201 is not working, the auxiliary oil circuit 10 has no pressure, and the second inlet 3022 of the shuttle valve 302 has no pressure input. The pressure oil from the main oil circuit 9 enters the first inlet 3021 of the shuttle valve 302, and the valve core of the shuttle valve 302 is switched to the right position. The pressure oil from the main oil circuit 9 is then output from its outlet 3023 to the control port X of the cartridge valve 303 after passing through the first inlet 3021 of the shuttle valve 302. The cartridge valve 303 remains closed under the action of the high-pressure oil at the control port X, preventing the hydraulic oil from the main oil circuit 9 from entering the auxiliary oil circuit 10 through the cartridge valve 303, ensuring that no oil flows into the auxiliary oil circuit 10 when the main pump supplies oil independently.

[0029] When the main pump finishes working independently, the main servo driver 101 controls the main servo motor 102 to reverse and release pressure based on the pressure signal fed back by the main pressure sensor 7, until the pressure detected by the main pressure sensor 7 is zero.

[0030] (3) Independent working mode of auxiliary pump When the system requires only a small flow rate and is supplied with oil by the auxiliary pump alone, the host computer outputs an independent working command for the auxiliary pump; The auxiliary servo driver 201 controls the auxiliary servo motor 202 to rotate forward, driving the auxiliary fixed displacement pump 203 to draw oil from the oil tank 4, and the hydraulic oil is output to the auxiliary oil circuit 10.

[0031] At this time, the reversing valve 301 is not energized and is in the right position ( Figure 2 As shown), its P port is connected to its A1 port. When the main servo drive 101 is not working, the main oil circuit 9 has no pressure, and the first inlet 3021 of the shuttle valve 302 has no pressure input. The pressurized oil from the auxiliary oil circuit 10 enters the second inlet 3022 of the shuttle valve 302, and the valve core of the shuttle valve 302 is switched to the left position. The pressurized oil from the auxiliary oil circuit 10 is then output from its outlet 3023 to the control port X of the cartridge valve 303 after passing through the second inlet 3022 of the shuttle valve 302. The cartridge valve 303 remains closed under the action of the high-pressure oil at the control port X, preventing the hydraulic oil from the auxiliary oil circuit 10 from entering the main oil circuit 9 through the cartridge valve 303, thus ensuring that no oil flows into the main oil circuit 9 when the auxiliary pump supplies oil independently.

[0032] When the auxiliary pump finishes its independent operation, the auxiliary servo drive 201 controls the auxiliary servo motor 202 to reverse and release pressure based on the pressure signal fed back by the auxiliary pressure sensor 8, until the pressure detected by the auxiliary pressure sensor 8 is zero. The residual pressure in the auxiliary oil circuit 10 is discharged back to the oil tank 4 through the reverse rotation of the auxiliary fixed displacement pump 203, completely eliminating the residual pressure in the pipeline.

[0033] (4) Main and auxiliary pumps operate synchronously and independently When the system requires only a small flow rate and the main and auxiliary pumps need to work synchronously and independently, the host computer simultaneously outputs instructions for the main and auxiliary pumps to work independently. The main servo driver 101 controls the main servo motor 102 to rotate forward, driving the main fixed pump 103 to draw oil from the oil tank 4 and output hydraulic oil to the main oil circuit 9. The auxiliary servo driver 201 controls the auxiliary servo motor 202 to rotate forward, driving the auxiliary fixed pump 203 to draw oil from the oil tank 4 and output hydraulic oil to the auxiliary oil circuit 10. At this time, the reversing valve 301 is not energized and is in the right position ( Figure 2 As shown), its P port is connected to its A1 port. The pressure oil from the main oil circuit 9 enters the first inlet 3021 of the shuttle valve 302, and the pressure oil from the auxiliary oil circuit 10 enters the second inlet 3022 of the shuttle valve 302. Due to the characteristics of the shuttle valve 302, it will select the higher pressure of the first inlet 3021 and the second inlet 3022 to output to the outlet 3023, and connect to the control port X of the cartridge valve 303. The cartridge valve 303 is kept closed under the action of the high pressure oil at the control port X, ensuring that the main oil circuit 9 and the auxiliary oil circuit 10 do not cross-contaminate when they work synchronously and independently.

[0034] When the main and auxiliary pumps finish operating synchronously and independently, the main servo driver 101 and the auxiliary servo driver 201 control the corresponding main and auxiliary servo motors (102, 202) to reverse and release pressure according to the pressure signals fed back by the main and auxiliary pressure sensors (7, 8) until the pressure detected by the main and auxiliary pressure sensors (7, 8) is zero. The residual pressure in the main and auxiliary oil circuits (9, 10) is discharged back to the oil tank 4 through the reverse rotation of the main and auxiliary fixed displacement pumps (103, 203), completely eliminating the residual pressure in the pipeline.

Claims

1. A servo motor hydraulic confluence system, comprising an oil tank, an energy unit, a control unit, and a main oil circuit and a secondary oil circuit, wherein the energy unit includes a main energy unit and a secondary energy unit, the main energy unit includes a main servo motor and a main fixed displacement pump, and the secondary energy unit includes a secondary servo motor and a secondary fixed displacement pump, wherein the oil inlets of the main fixed displacement pump and the secondary fixed displacement pump are both connected to the oil tank, characterized in that: The control unit includes a directional valve, a cartridge valve, and a shuttle valve; The main oil circuit is connected to the first working oil port of the cartridge valve and the first oil inlet of the shuttle valve, and the main oil circuit is connected to the oil outlet of the main metering pump. The auxiliary oil circuit is connected to the second working oil port of the cartridge valve and the oil inlet of the reversing valve, and the auxiliary oil circuit is connected to the oil outlet of the auxiliary metering pump. The control port of the cartridge valve is connected to the outlet port of the shuttle valve; The first working port of the reversing valve is connected to the second inlet port of the shuttle valve; The return port of the reversing valve is connected to the oil tank.

2. The servo motor hydraulic confluence system as described in claim 1, characterized in that... The main power unit also includes a main servo driver, which is electrically connected to the main servo motor and is used to control the main servo motor to rotate forward or in reverse. The secondary power unit also includes a secondary servo driver, which is electrically connected to the secondary servo motor and is used to control the secondary servo motor to rotate forward or in reverse.

3. The servo motor hydraulic confluence system as described in claim 1, characterized in that... An oil suction filter is provided between the oil inlet of the main metering pump and the auxiliary metering pump and the oil tank. The first port of the oil suction filter is connected to the oil inlet of the corresponding metering pump, and the second port of the oil suction filter is connected to the oil tank.

4. The servo motor hydraulic confluence system as described in claim 2, characterized in that... Pressure sensors are installed at the oil outlets of both the main metering pump and the auxiliary metering pump, and the pressure sensors are electrically connected to the corresponding main servo driver and auxiliary servo driver.

5. A servo motor hydraulic confluence system as described in claim 1, characterized in that... The aforementioned directional valve is a two-position four-way solenoid directional valve.

6. The servo motor hydraulic confluence system as described in claim 1, characterized in that... The shuttle valve is a valve with a logic OR function, used to select the higher pressure of the first oil inlet and the second oil inlet to output to the oil outlet.

7. A servo motor hydraulic confluence system as described in claim 1, characterized in that... The cartridge valve is a two-way logic cartridge valve.

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