A deep-sea underwater integrated electro-hydraulic actuator system adopting a pump-valve combination

Abstract

The application discloses a deep-sea underwater integrated electro-hydraulic actuator system adopting a pump-valve combination, which comprises a hydraulic cylinder, a pump control assembly and a valve control assembly; the pump control assembly comprises a constant delivery pump, a first on-off valve and a second on-off valve; the valve control assembly comprises a large-flow proportional valve, a small-flow proportional valve, a deep-sea compensation accumulator and a third on-off valve; the constant delivery pump, the first on-off valve and the rod cavity of the hydraulic cylinder are sequentially connected through pipelines; the constant delivery pump, the second on-off valve and the rodless cavity of the hydraulic cylinder are sequentially connected through pipelines; the constant delivery pump, the third on-off valve and the deep-sea compensation accumulator are sequentially connected through pipelines; and the rodless cavity of the hydraulic cylinder is connected with the large-flow proportional valve and the small-flow proportional valve through pipelines. The application can complete two control modes of an actuator, realizes large-flow control and high efficiency and energy saving through the pump control assembly, and realizes attitude keeping and emergency action by supplying the required flow to the rodless cavity of the actuator through the large-flow proportional valve and the small-flow proportional valve of the valve control assembly.

Description

Technical Field

[0001] This invention relates to the field of actuators, specifically to a deep-sea integrated electro-hydraulic actuator system employing a combination of pumps and valves. Background Technology

[0002] With the increasing demands for offshore oil and gas development, deep-sea mineral extraction, deep-sea scientific exploration, and underwater engineering operation and maintenance, underwater operation equipment is facing stringent requirements for actuators, including high power density, high reliability, long lifespan, and low maintenance. Electro-hydraulic actuators, due to their high output force per unit volume and strong adaptability to deep-sea environments, have become the primary choice for actuators in deep-sea underwater equipment.

[0003] Existing underwater electro-hydraulic actuators consist of a pump, valve, and cylinder, forming an integrated pump-control system. However, they have shortcomings in system response and reliability. Valve-controlled systems offer advantages to improve response, requiring a pressure source, typically achieved using an accumulator. However, underwater external pressure significantly affects the accumulator. Without pressure compensation, the absolute pressure and usable volume of the gas accumulator deviate with water depth, leading to a decrease in the gauge pressure relative to seawater and the amount of energy that can be released, making it difficult to guarantee positive pressure margin and long-term stable output. Furthermore, to improve reliability, the EHA (Emergency Hydraulic Actuator) needs an emergency reset function, which can be achieved using the energy stored in the accumulator. The key to the system's functionality lies in how to promptly replenish energy after the accumulator has released all its energy.

[0004] In terms of energy management, deep-sea platforms are typically limited by cable power supply capacity or payload battery capacity. Actuators generate considerable recoverable hydraulic energy during descent, deceleration, or load feedback phases. Existing systems often dissipate this energy through overflow or throttling, increasing heat load and energy consumption. Introducing energy recovery channels and integrating them with external pressure compensation systems is crucial for improving overall system energy efficiency and endurance.

[0005] Under the combined constraints of high external pressure, low temperature and limited energy supply in the deep sea, pump control systems suffer from poor dynamic response performance and lower control accuracy compared to valve control. Valve control, on the other hand, suffers from unacceptable energy and heat loss. Either pump control or valve control alone will expose unacceptable shortcomings. Summary of the Invention

[0006] The purpose of this invention is to provide a deep-sea integrated electro-hydraulic actuator system employing a pump and valve combination to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A deep-sea integrated electro-hydraulic actuator system employing a pump-valve combination includes a hydraulic cylinder, a pump control component, and a valve control component;

[0009] The pump control assembly includes a metering pump, a first switching valve, and a second switching valve;

[0010] The valve control assembly includes a high-flow proportional valve, a low-flow proportional valve, a deep-sea compensated accumulator, and a third switching valve.

[0011] The first inlet / outlet of the fixed displacement pump, the first switching valve, and the rod chamber of the hydraulic cylinder are connected in sequence through pipelines. The second inlet / outlet of the fixed displacement pump, the second switching valve, and the rodless chamber of the hydraulic cylinder are connected in sequence through pipelines. The second inlet / outlet of the fixed displacement pump, the third switching valve, and the deep-sea compensating accumulator are connected in sequence through pipelines. The rodless chamber of the hydraulic cylinder is connected to a large-flow proportional valve and a small-flow proportional valve through pipelines. The large-flow proportional valve and the small-flow proportional valve are connected to the deep-sea compensating accumulator through pipelines.

[0012] Furthermore, the first and second inlet / outlet ports of the metering pump are respectively connected to the flow matching valve via pipelines. The flow matching valve is respectively connected to the first and second relief valve via pipelines. The first relief valve is connected to the rod chamber of the hydraulic cylinder via a pipeline, and the second relief valve is connected to the rodless chamber of the hydraulic cylinder via a pipeline.

[0013] Furthermore, the deep-sea compensating accumulator, the first overflow valve, and the second overflow valve are respectively connected to the deep-sea compensator through pipelines.

[0014] Furthermore, a third overflow valve is installed on the pipeline connecting the deep-sea compensating accumulator and the deep-sea compensator.

[0015] Furthermore, a check valve is installed on the pipeline connecting the deep-sea compensating accumulator and the third switching valve. The check valve allows oil to flow from the third switching valve to the deep-sea compensating accumulator, but does not allow oil to flow from the deep-sea compensating accumulator to the third switching valve.

[0016] Furthermore, a filter is installed on the pipeline connecting the deep-sea compensating accumulator and the third switching valve.

[0017] Furthermore, the deep-sea compensated accumulator includes an accumulator tank. The inner cavity of the accumulator tank is divided into a first tank cavity and a second tank cavity by a partition. A main dividing piston is sealed and slidably connected inside the first tank cavity. The main dividing piston divides the first tank cavity into a first gas cavity and an oil cavity. A sea pressure compensating piston is sealed and slidably connected inside the second tank cavity. The sea pressure compensating piston divides the second tank cavity into a second gas cavity and a seawater cavity. The first gas cavity, oil cavity, second gas cavity, and seawater cavity are arranged sequentially. A piston rod is sealed and slidably connected to the partition. The two ends of the piston rod are respectively connected to the main dividing piston and the sea pressure compensating piston. The oil cavity is respectively connected to a large flow proportional valve, a small flow proportional valve, and a third switching valve through pipelines.

[0018] Furthermore, a seawater inlet is provided on the seawater cavity, and a filter screen is provided on the seawater inlet.

[0019] Furthermore, the metering pump is connected to a motor.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1) This invention can achieve two control modes for the actuator. It achieves high flow control and high efficiency and energy saving through the pump control component, and supplies the flow required for maintenance to the rodless chamber of the actuator through the valve control component via the high flow proportional valve and the low flow proportional valve, so as to achieve attitude maintenance and emergency action; and improve the redundancy of the system.

[0022] 2) This invention uses a dual-piston deep-sea compensating accumulator, which enables the compensator to adapt to changes in deep-sea pressure, ensuring that the absolute pressure of the accumulator's air chamber changes synchronously with the water depth. At the same time, the dual-air chamber design ensures that even if only one air chamber leaks, the other air chamber can still work, providing redundancy.

[0023] 3) Pump control covers the main flow rate, while valve control only handles error compensation, significantly reducing valve throttling losses and heat generation; during standby, the pump unloading condition reduces idling power consumption; during return and light load return flow, the proportional valve prioritizes recharging the accumulator to achieve energy recovery, and hydraulic energy is recovered during the descent, deceleration, or load feedback phase of the actuator; seawater reference enables the accumulator to maintain stable usable energy at different water depths, further improving the overall energy efficiency and range.

[0024] 4) When the accumulator pressure relative to the ambient pressure drops below the threshold due to power-on reset, intermittent power loss recovery, or changes in water depth or temperature, the control system automatically enters the energy storage charging mode: the actuator oil supply valve is closed, the third switch valve is opened, and the motor drives the quantitative pump to charge the accumulator with oil at a limited slope until the set upper limit is reached, after which the pump is unloaded and put into standby mode; combined with seawater compensation, a self-recovery mechanism of passive pressure stabilization + active recharging is formed, which keeps the accumulator in a release state for a long time to perform an emergency reset, meeting the needs of long-term unattended operation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention.

[0026] Figure 2 This is a schematic diagram of the deep-sea compensating accumulator structure in this invention.

[0027] In the diagram: 1. Motor; 2. Metering pump; 3. Deep-sea compensator; 4. Flow matching valve; 5. First switching valve; 6. Second switching valve; 7. Third switching valve; 8. Large flow proportional valve; 9. Small flow proportional valve; 10. Hydraulic cylinder; 10. Rod chamber 1001; Rodless chamber 1002; 11. First relief valve; 12. Second relief valve; 13. Third relief valve; 14. Check valve; 15. Deep-sea compensating accumulator; 15. First air chamber 1501; Oil chamber 1502; Second air chamber 1503; Seawater chamber 1504; Filter screen 1505; Ocean pressure compensating piston 1506; Piston rod 1507; Main separator piston 1508; Accumulator tank 1509; Filter 16. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1 and Figure 2 A deep-sea integrated electro-hydraulic actuator system employing a pump-valve combination includes a hydraulic cylinder 10, a pump control assembly, and a valve control assembly. The pump control assembly includes a fixed-displacement pump 2, a first switching valve 5, and a second switching valve 6. The hydraulic cylinder 10 is a single-rod cylinder actuator. The fixed-displacement pump 2 is connected to a motor 1. The valve control assembly includes a high-flow proportional valve 8, a low-flow proportional valve 9, a deep-sea compensating accumulator 15, and a third switching valve 7. The first inlet and outlet ports of the fixed displacement pump 2, the first switching valve 5, and the rod chamber 1001 of the hydraulic cylinder 10 are connected in sequence through pipelines. The second inlet and outlet ports of the fixed displacement pump 2, the second switching valve 6, and the rodless chamber 1002 of the hydraulic cylinder 10 are connected in sequence through pipelines. The second inlet and outlet ports of the fixed displacement pump 2, the third switching valve 7, and the deep-sea compensating accumulator 15 are connected in sequence through pipelines. The rodless chamber 1002 of the hydraulic cylinder 10 is connected to the large flow proportional valve 8 and the small flow proportional valve 9 through pipelines. The large flow proportional valve 8 and the small flow proportional valve 9 are connected to the deep-sea compensating accumulator 15 through pipelines. The deep-sea compensating accumulator 15 is connected to the hydraulic cylinder 10 in parallel through the large flow proportional valve 8 and the small flow proportional valve 9.

[0030] Among them, the rod chamber 1001 is the chamber of the hydraulic cylinder 10 with a telescopic rod. When it increases in size, the telescopic rod shortens. The rodless chamber 1002 is the chamber of the hydraulic cylinder 10 without a telescopic rod. When it increases in size, the telescopic rod extends.

[0031] Continue reading Figure 1In one embodiment of the present invention, the first inlet and outlet ports and the second inlet and outlet ports of the metering pump 2 are respectively connected to the flow matching valve 4 through pipelines. The flow matching valve 4 is respectively connected to the first relief valve 11 and the second relief valve 12 through pipelines. The first relief valve 11 is connected to the rod chamber 1001 of the hydraulic cylinder 10 through a pipeline, and the second relief valve 12 is connected to the rodless chamber 1002 of the hydraulic cylinder 10 through a pipeline.

[0032] Continue reading Figure 1 In one embodiment of the present invention, the first overflow valve 11, the second overflow valve 12, and the deep-sea compensating accumulator 15 are respectively connected to the deep-sea compensator 3 via pipelines. A third overflow valve 13 is installed on the pipeline connecting the deep-sea compensating accumulator 15 and the deep-sea compensator 3. The deep-sea compensator 3 is connected to the rod chamber 1001 and the rodless chamber 1002 of the hydraulic cylinder 10 via the first overflow valve 11 and the second overflow valve 12, respectively, and is connected to the deep-sea compensating accumulator 15 via the third overflow valve 13. The third overflow valve 13 is used for overpressure protection.

[0033] Continue reading Figure 1 In one embodiment of the present invention, a one-way valve 14 and a filter 16 are provided on the pipeline connecting the deep-sea compensating accumulator 15 and the third switching valve 7. The one-way valve 14 allows oil to flow from the third switching valve 7 to the deep-sea compensating accumulator 15, but does not allow oil to flow from the deep-sea compensating accumulator 15 to the third switching valve 7.

[0034] Continue reading Figure 2In one embodiment of the present invention, the deep-sea compensated accumulator 15 includes an accumulator tank 1509. The inner cavity of the accumulator tank 1509 is divided into a first tank cavity and a second tank cavity by a partition. A main dividing piston 1508 is sealed and slidably connected in the first tank cavity. The main dividing piston 1508 divides the first tank cavity into a first gas cavity 1501 and an oil cavity 1502. A sea pressure compensated piston 1506 is sealed and slidably connected in the second tank cavity. The sea pressure compensated piston 1506 divides the second tank cavity into a second gas cavity 1503 and a seawater cavity 1504. The first gas cavity 1501, the oil cavity 1502, the second gas cavity 1503, and the seawater cavity 1504 are arranged sequentially. A piston rod 1507 is sealed and slidably connected on the partition. The two ends of the piston rod 1507 are respectively connected to the main dividing piston 1508 and the sea pressure compensated piston 1506. The pressure-compensating piston 1506 transmits the environmental pressure within the seawater chamber 1504 to the second air chamber 1503, and then to the first air chamber 1501 via the piston rod 1507, compressing both chambers and ensuring that the absolute pressure of the air chambers changes synchronously with the water depth. The oil chamber 1502 is connected via pipelines to the large-flow proportional valve 8, the small-flow proportional valve 9, the filter 16, and the third relief valve 13. In other words, the oil port of the oil chamber 1502 is connected to the rodless chamber 1002 of the hydraulic cylinder 10 via the large-flow proportional valve 8 and the small-flow proportional valve 9, and to the metering pump 2 via the check valve 14, the filter 16, and the third switching valve 7. The return flow paths of the rodless chamber 1002 and the rod chamber 1001 of the hydraulic cylinder 10 are connected to the metering pump 2 via the first switching valve 5 and the second switching valve 6, or are returned to the deep-sea compensating accumulator 15 via the large-flow proportional valve 8 and the small-flow proportional valve 9 to achieve energy recovery. The large-flow proportional valve 8, the small-flow proportional valve 9, the filter 16, and the third overflow valve 13 are all connected to the deep-sea compensating accumulator 15 via pipelines. A seawater inlet is provided on the seawater chamber 1504, and a filter screen 1505 is provided on the seawater inlet. Inflation / de-inflation ports are arranged on the first air chamber 1501 and the second air chamber 1503.

[0035] The deep-sea compensating accumulator 15 is a gas accumulator with seawater reference function. Its gas chamber forms a pressure reference with the seawater chamber 1504 through the compensating piston, so that the absolute pressure of the gas chamber changes synchronously with the external hydrostatic pressure, thereby maintaining the target gauge pressure and basically constant usable energy relative to the seawater at different water depths; its seawater inlet is equipped with a filter screen and sand prevention seal.

[0036] The hydraulic system includes: pump control circuit, valve control circuit, pump-valve coupling control circuit, energy recovery circuit, recharge circuit, and protection circuit.

[0037] The pump control circuit consists of a motor 1, a fixed displacement pump 2, a first switching valve 5, a second switching valve 6, and corresponding pipelines. This circuit can achieve high flow control and can play a role in the high efficiency and energy saving of pump control with low heat loss in the overall hydraulic circuit.

[0038] The valve control circuit consists of a deep-sea compensated accumulator 15, a large-flow proportional valve 8, a small-flow proportional valve 9, and corresponding pipelines. This circuit enables the hydraulic cylinder to respond quickly and move small displacements, and plays a role in the high-precision control and high-response characteristics of pump control in the overall hydraulic circuit.

[0039] The pump-valve coupled control loop consists of a motor 1, a fixed displacement pump 2, a first switching valve 5, a second switching valve 6, a first proportional valve 8, a second proportional valve 9, a deep-sea compensating accumulator 15, and a third switching valve 7. This loop combines the advantages of pump control and valve control, employing a "pump control feedforward + valve control feedback compensation" control method. The pump control section provides the majority of the flow and base pressure to the hydraulic cylinder 10 based on the target motion feedforward calculation results. The valve control section uses an independent metering method at the load port to perform fine compensation for errors generated by pump control with small flow rates. This significantly reduces valve throttling losses, lowers heat generation, and improves system energy efficiency while ensuring dynamic performance and control accuracy. The overall hydraulic loop leverages the high-precision control, high-response characteristics, and high energy efficiency of pump-valve coupled control.

[0040] The energy recovery circuit consists of a first proportional valve 8, a second proportional valve 9, a deep-sea compensating accumulator 15, and a hydraulic cylinder 10. This circuit enables the actuator to recover hydraulic energy during descent, deceleration, or load feedback phases. When the actuator port pressure is lower than a set threshold, the deep-sea compensating accumulator 15 supplies energy to the rodless chamber 1002 of the hydraulic cylinder 10 as needed via the first proportional valve 8 and the second proportional valve 9, thus releasing the stored energy. When the actuator returns or the external load returns oil, the return flow is metered and recharged to the deep-sea compensating accumulator 15 via the first proportional valve 8 and the second proportional valve 9. The second proportional valve 9 is preferred for selecting the high-pressure side for recovery. When the pressure of the deep-sea compensating accumulator 15 reaches the upper limit or the temperature rise exceeds the threshold, it automatically overflows to the return oil passage.

[0041] The recharge circuit consists of motor 1, metering pump 2, first switching valve 5, third switching valve 7, check valve 14, and filter 16. This circuit enables the controller to perform an "energy storage and charging" operation when the deep-sea compensating accumulator 15 experiences power-on reset, intermittent power loss recovery, or when the pressure relative to the ambient surface of the deep-sea compensating accumulator 15 falls below a set threshold due to changes in water depth and temperature. This operation keeps the first proportional valve 8 and second proportional valve 9 closed, while opening the third switching valve 7 to conduct the energy storage branch, allowing motor 1 and metering pump 2 to charge the deep-sea compensating accumulator 15 with oil. Simultaneously, the deep-sea compensating accumulator 15 ensures that the EHA (Energy Harness) has an emergency reset function, allowing the recharge circuit to promptly replenish the energy of the deep-sea compensating accumulator 15 after energy release. The overall circuit ensures that the deep-sea compensating accumulator 15 is always in a release-ready state for extended periods.

[0042] The protection circuit consists of flow matching valve 4, first overflow valve 11, second overflow valve 12, and third overflow valve 13. This circuit can effectively protect the circuit and maximize the protection of the overall structure in the event of external load, equipment failure, or power failure. It also releases and protects the deep-sea compensating accumulator 15 in the event of overcharging. The passive switching of the flow matching valve 4 ensures the continuity of the return oil circuit.

[0043] The first switching valve 5, the second switching valve 6, and the third switching valve 7 mentioned above are all two-way switching valves. The large-flow proportional valve 8 and the small-flow proportional valve 9 mentioned above are both two-way proportional cartridge valves. The structure and working principle of the flow matching valve 4 mentioned above are exactly the same as the flow matching valve in patent CN120212100A, which can be referred to in detail in patent CN120212100A.

[0044] The pump control assembly and valve control assembly of this invention are connected in parallel to the return oil circuit composed of the deep-sea compensator 3 and the flow matching valve 5 via the first relief valve 11, the second relief valve 12, and the third relief valve 13. The pump control assembly and valve control assembly are connected in parallel to the hydraulic cylinder 10 at the other end to independently control the flow rate. A check valve 14, a filter 16, and other components are also provided to form a complete oil circuit.

[0045] The deep-sea compensating accumulator 15 is pre-charged on land, and inert gas is injected into the first air chamber 1501 and the second air chamber 1503 in a deck environment. After launching, seawater connects to the seawater chamber 1504 of the deep-sea compensating accumulator 15 through the seawater inlet of the accumulator. The sea pressure compensation piston 1506 transmits the external hydrostatic pressure to the second air chamber 1503, and then to the first air chamber 1501 through the piston rod 1507, so that the absolute pressure of the two air chambers changes synchronously with the water depth, thereby maintaining the target gauge pressure relative to the seawater and a basically constant available energy at different water depths. A filter screen 1505 and a sand-proof seal are installed at the seawater inlet to suppress particle intrusion. To suppress micro-disturbance vibration, a small throttling orifice can be set in the air passage connecting the two air chambers to achieve static isobaric and dynamic decoupling.

[0046] Start-up and standby: Upon power-up, motor 1 is shut off; first switching valve 5 and second switching valve 6 remain closed to isolate hydraulic cylinder 10; third switching valve 7 is closed to isolate deep-sea compensating accumulator 15; system safety pressure limiting is established through first relief valve 11, second relief valve 12, and third relief valve 13. A stable back pressure is formed on the return oil side by flow matching valve 4 to ensure lubrication, prevent cavitation, and stabilize valve core transition.

[0047] Accumulator recharging mode (pump active charging): When the oil-side pressure of the deep-sea compensating accumulator 15 is low, the controller closes the first switch valve 5, the second switch valve 6, the large flow proportional valve 8, and the small flow proportional valve 9, and opens the third switch valve 7, allowing the fixed displacement pump 2 to charge the deep-sea compensating accumulator 15 with oil through the check valve 14 and the filter 16. After the pressure of the deep-sea compensating accumulator 15 reaches the upper limit, the third switch 7 is closed and the fixed displacement pump 2 enters the unloading or execution mode.

[0048] Pump-controlled extension operation: When there is no external load, and the hydraulic cylinder 10 needs to extend, the motor 1 drives the fixed displacement pump 2, opens the second switch valve 6 to supply oil to the rodless chamber 1002, opens the first switch valve 5 and closes the third switch valve 7 to allow the rod chamber 1001 to return through the return oil circuit. When the external load has a tendency to assist, in order to prevent overspeed and cavitation, when the instantaneous demand flow of the rodless chamber 1002 is greater than the output of the fixed displacement pump 2, the third switch valve 7 is briefly opened, and the deep-sea compensating accumulator 15 replenishes the flow to the rodless chamber 1002. After the pressure is restored, the third switch valve 7 is closed, and the return oil returns to the return oil circuit through the flow matching valve 5.

[0049] Pump-controlled retraction mode: When there is no external load and the hydraulic cylinder 10 needs to retract, the motor 1 drives the fixed displacement pump 2, opens the first switch valve 5 to supply oil to the rod chamber 1001, opens the second switch valve 6 and closes the third switch valve 7 to allow the rodless chamber 1002 to return through the return oil circuit. When the external load has a boosting tendency, in order to improve energy efficiency, if the return oil circuit pressure is greater than the accumulator oil circuit pressure, the second switch valve 6 is closed and the large flow proportional valve 8 is opened (the small flow proportional valve 9 is closed) to recover energy with a large flow rate. If the external load has a resistance tendency, if the return oil circuit pressure is greater than the accumulator oil circuit pressure, the large flow proportional valve 8 can be opened at the same time to increase the return oil flow rate with a large flow rate (the small flow proportional valve 9 is closed). When the flow rate is small, the small flow proportional valve 9 is opened (the large flow proportional valve 8 is closed) to increase the return oil flow rate with a small flow rate.

[0050] Accumulator energy recovery operation (energy recovery charging): When the external load has a tendency to assist, in order to improve energy efficiency, the controller closes the first switch valve 5, the second switch valve 6, and the third switch valve 7, and opens the large flow proportional valve 8 or the small flow proportional valve 9, so that the rodless chamber 1002 charges the deep-sea compensating accumulator 15 with oil through the large flow proportional valve 8 or the small flow proportional valve 9; when the external load movement causes the hydraulic cylinder to run at a high speed, the large flow proportional valve 8 is opened (the small flow proportional valve 9 is closed) for large flow recovery; when the running speed is slow, the small flow proportional valve 9 is opened (the large flow proportional valve 8 is opened) for small flow recovery; after the pressure of the deep-sea compensating accumulator 15 reaches the upper limit, the second switch 6 is opened for oil return or oil return is carried out through the third relief valve 13.

[0051] Valve-controlled fine-tuning condition: When high dynamic and small displacement fine control is required, the first switching valve 5 and the second switching valve 6 are kept closed, and the hydraulic cylinder 10 is driven by the large flow proportional valve 8 and the small flow proportional valve 9. The oil from the deep-sea compensating accumulator 15 is used for small flow high-speed correction; at this time, the third switching valve 7 is closed, so that the stored energy is given priority for port-level compensation and peak shaving.

[0052] High flow rate supply condition: When there is a large stroke or high power demand, the first switch valve 5 and the second switch valve 6 are opened, and the fixed displacement pump 2 supplies oil to the target cavity. The high flow rate proportional valve 8 and the low flow rate proportional valve 9 compensate for the pump control error with a small opening. The third switch valve 7 is closed, and the deep-sea compensating accumulator 15 is connected in parallel to the metering node to provide instantaneous flow for commutation and load disturbance to suppress pressure spikes and cavitation.

[0053] Deep-sea compensation circuit: Deep-sea compensator 3 synchronizes the overall pressure with the water depth, improving the stability of the system at different depths; flow matching valve 4 establishes a constant back pressure for the return oil, which is beneficial for the valve core transition and cavitation prevention of flow matching valve 4. Deep-sea compensation accumulator 15 synchronizes the gas chamber pressure with the water depth, and overpressure on the side of deep-sea compensation accumulator 15 is implemented by a dedicated protection element.

[0054] Protection circuit: Relief valves are connected in parallel on both sides of the hydraulic cylinder 10 and the deep-sea compensating accumulator 15 to prevent external loads from directly driving it.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A deep-sea integrated electro-hydraulic actuator system employing a pump and valve combination, characterized in that, Includes hydraulic cylinder (10), pump control assembly, and valve control assembly; The pump control assembly includes a metering pump (2), a first switching valve (5), and a second switching valve (6). The valve control assembly includes a large flow proportional valve (8), a small flow proportional valve (9), a deep-sea compensating accumulator (15), and a third switching valve (7). The first inlet and outlet ports of the metering pump (2), the first switching valve (5), and the rod chamber (1001) of the hydraulic cylinder (10) are connected in sequence through pipelines. The second inlet and outlet ports of the metering pump (2), the second switching valve (6), and the rodless chamber (1002) of the hydraulic cylinder (10) are connected in sequence through pipelines. The second inlet and outlet ports of the metering pump (2), the third switching valve (7), and the deep-sea compensating accumulator (15) are connected in sequence through pipelines. The rodless chamber (1002) of the hydraulic cylinder (10) is connected to the large flow proportional valve (8) and the small flow proportional valve (9) through pipelines. The large flow proportional valve (8) and the small flow proportional valve (9) are connected to the deep-sea compensating accumulator (15) through pipelines. The first inlet and outlet ports and the second inlet and outlet ports of the quantitative pump (2) are respectively connected to the flow matching valve (4) through pipelines. The flow matching valve (4) is respectively connected to the first relief valve (11) and the second relief valve (12) through pipelines. The first relief valve (11) is connected to the rod chamber (1001) of the hydraulic cylinder (10) through pipelines. The second relief valve (12) is connected to the rodless chamber (1002) of the hydraulic cylinder (10) through pipelines. The deep-sea compensating accumulator (15), the first overflow valve (11), and the second overflow valve (12) are respectively connected to the deep-sea compensator (3) through pipelines; A third overflow valve (13) is installed on the pipeline connecting the deep-sea compensating accumulator (15) and the deep-sea compensator (3). The deep-sea compensating accumulator (15) includes an accumulator tank (1509). The inner cavity of the accumulator tank (1509) is divided into a first tank cavity and a second tank cavity by a partition. A main dividing piston (1508) is slidably connected in the first tank cavity, and the main dividing piston (1508) divides the first tank cavity into a first gas cavity (1501) and an oil cavity (1502). A sea pressure compensating piston (1506) is slidably connected in the second tank cavity, and the sea pressure compensating piston (1506) divides the second tank cavity into a second gas cavity and an oil cavity. The first air chamber (1501), oil chamber (1502), second air chamber (1503) and seawater chamber (1504) are arranged in sequence. The piston rod (1507) is sealed and slidably connected on the partition plate. The two ends of the piston rod (1507) are respectively connected to the main separating piston (1508) and the sea pressure compensation piston (1506). The oil chamber (1502) is respectively connected to the large flow proportional valve (8), the small flow proportional valve (9) and the third switching valve (7) through pipelines.

2. The deep-sea integrated electro-hydraulic actuator system employing a pump and valve combination as described in claim 1, characterized in that, A check valve (14) is installed on the pipeline connecting the deep-sea compensating accumulator (15) and the third switching valve (7). The check valve (14) allows oil to flow from the third switching valve (7) to the deep-sea compensating accumulator (15) and does not allow oil to flow from the deep-sea compensating accumulator (15) to the third switching valve (7).

3. The deep-sea integrated electro-hydraulic actuator system employing a pump and valve combination according to claim 2, characterized in that, A filter (16) is installed on the pipeline connecting the deep-sea compensating accumulator (15) and the third switching valve (7).

4. The deep-sea integrated electro-hydraulic actuator system employing a pump and valve combination according to claim 1, characterized in that, A seawater inlet is provided on the seawater cavity (1504), and a filter screen (1505) is provided on the seawater inlet.

5. A deep-sea integrated electro-hydraulic actuator system employing a pump and valve combination according to claim 1, characterized in that, The metering pump (2) is connected to the motor (1).

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