A dual-redundant servo valve and its application

Abstract

The present invention provides a dual-redundant servo valve and its application, belonging to the field of electro-hydraulic servo control; comprising a housing, two sets of electro-hydraulic servo valves and a hydraulic pressure sensor; the two sets of electro-hydraulic servo valves are connected in parallel and arranged in the housing, respectively defined as a left valve and a right valve; the hydraulic pressure of the left valve is monitored by the hydraulic pressure sensor; the left valve is set as the main valve, and the right valve is set as the backup valve; when the right valve is a hot backup, the two sets of electro-hydraulic servo valves are started at the same time to control the supply pressure, and if one of them fails, the other can independently complete the control target; when the right valve is a cold backup, the backup valve is started only when the main valve fails to complete the control target. The dual-redundant servo valve proposed in the present invention is composed of a pair of twin electro-hydraulic servo valves on a common housing. The reliability model of the left valve and the right valve of the valve system is a parallel relationship. As long as one of the electro-hydraulic servo valves is normal, the dual-redundant servo valve can complete the regulation and control of the output pressure.

Description

Technical Field

[0001] The invention belongs to the field of electro-hydraulic servo control, and in particular relates to a dual-redundancy servo valve and its application. Background Art

[0002] The electro-hydraulic servo valve is a key component of servo control systems and is widely used in high-tech fields such as aviation and aerospace. It primarily consists of an electromechanical transducer, a pilot stage (pre-stage), and a power stage. Its operating principle generally involves using a current signal to control a torque motor, which in turn controls the pre-stage. The pre-stage hydraulic pressure is then amplified to operate a spool valve, with the desired flow and pressure outputted through the spool valve's load port. For example, in aircraft brakes, electro-hydraulic servo valves are used as anti-skid control valves to control brake pressure and prevent tire blowouts. Common electro-hydraulic pressure servo valves used in brake systems are mainly positive-gain, where output pressure increases with current, and negative-gain, where output pressure decreases with current. While structurally similar to flow servo valves, electro-hydraulic pressure servo valves have a single load output control port and require higher control accuracy than flow servo valves.

[0003] Electro-hydraulic pressure servo valves are precision electromechanical accessories. For example, the commonly used nozzle-flapper servo valve is susceptible to contaminants in the oil during use, which can degrade performance. This can cause nozzle blockage, delaying the timely release of pressure, or even preventing the brake pressure from being released at all, often leading to accidents such as tire blowouts. Currently, electro-hydraulic servo valves generally use a single-redundancy design. A small number of valves that employ a redundant design only achieve partial redundancy (such as electrical or motor redundancy). For example, the torque motor of an electro-hydraulic servo valve uses a dual-coil redundant design, improving the reliability of the electrical portion while leaving the mechanical hydraulic portion (pre-stage, spool stage) unredundant. Some electro-hydraulic servo valves use a torque motor pre-stage redundancy, but the spool stage uses a shared spool valve, failing to achieve true redundancy. There is already a dual-valve structure - referred to here as a conjoined dual-valve or single-body dual-chamber valve structure. However, the two electro-hydraulic servo valves are used to control independent objects. For example, each valve controls the wheel to which it is connected. However, the two valves share a housing, a main pressure supply port, and a main oil return port. The conjoined dual valve is still a servo valve without redundancy. Therefore, if a truly redundant dual-valve servo valve is adopted, the reliability and safety of the brake system can be improved. Summary of the Invention

[0004] Technical issues to be solved:

[0005] In order to avoid the shortcomings of the existing technology, the present invention provides a dual-redundant servo valve and its application. Two electro-hydraulic servo valves are arranged in parallel in the housing of the dual-redundant servo valve. The two electro-hydraulic servo valves work together to avoid the impact of failures, or when one valve fails, the other valve is started to work normally, thereby ensuring the stability of the servo valve operation. It can be used in aircraft braking systems to prevent tire blowouts.

[0006] The technical solution of the present invention is: a dual-redundant servo valve, comprising a housing, a hydraulic pressure sensor, and two sets of electro-hydraulic servo valves; the two sets of electro-hydraulic servo valves are connected in parallel and arranged in the housing, respectively defined as a left valve and a right valve; the hydraulic pressure of the left valve is monitored by the hydraulic pressure sensor;

[0007] The left valve is set as the main valve and the right valve is set as the backup valve; when the right valve is in hot backup mode, the two sets of electro-hydraulic servo valves are started simultaneously to control the supply pressure. If one of them fails, the other can independently complete the control target; when the right valve is in cold backup mode, the backup valve is started only when the main valve fails to complete the control target.

[0008] A further technical solution of the present invention is that: two sets of electro-hydraulic servo valves are installed in the inner cavity of the housing, and four hydraulic interfaces and one electrical interface are opened on the outer wall, which are respectively connected to corresponding components of the two sets of electro-hydraulic servo valves through built-in channels on the housing wall;

[0009] The four hydraulic interfaces are a pressure supply port, a load port, an oil return port, and a monitoring port, which are hydraulically connected to the system pressure source, the hydraulic actuator, the oil tank, and the hydraulic pressure sensor respectively; the electrical interface is electrically connected to the controller.

[0010] A further technical solution of the present invention is: the shell is a flat-roofed room-shaped block, which is formed by cutting a rectangular block by two symmetrical inclined planes. The upper part of the flat-roofed room is composed of a central top surface and two symmetrical inclined planes on both sides. The top surface is parallel to the bottom surface, and the inclination angle of the inclined plane is 30-60°; the oil return port is arranged on the top surface, the load port is arranged on the right inclined plane, the monitoring port is arranged on the left inclined plane, and the pressure supply port is arranged on the right inclined plane near the rear end surface; the rear end surface of the shell is provided with a circular boss, and the hydraulic oil filter is installed through the hole cavity at the center of the circular boss.

[0011] A further technical solution of the present invention is: the left valve and the right valve both include a torque motor, a pre-stage, and a slide valve stage, and the two torque motors are respectively arranged on the two side surfaces of the dual-redundant servo valve, that is, the left valve torque motor is arranged on the left side, and the right valve torque motor is arranged on the right side, and are respectively electrically connected to the electrical interface on the shell; the pre-stage and the slide valve of the left valve and the right valve are symmetrically arranged on both sides of the shell.

[0012] A further technical solution of the present invention is: the oil inlets of the left valve and the right valve are both connected to the pressure supply port on the housing through a built-in oil circuit; the load ports of the left valve and the right valve are both connected to the load port on the housing through a built-in oil circuit; and the oil return ports of the left valve and the right valve are both connected to the oil return port on the housing through a built-in oil circuit.

[0013] A further technical solution of the present invention is: the pressure supply port on the housing extends into the housing and is divided into two oil circuits, one oil circuit is connected to the left valve oil inlet; the other oil circuit is connected to the right valve pre-stage oil inlet.

[0014] A further technical solution of the present invention is that the pressure supply port is provided with a hydraulic oil filter for filtering out oil source pollutants to prevent dirt from invading the valve, and the hydraulic oil filter accuracy is 3-15μ.

[0015] A further technical solution of the present invention is: the outer wall of the shell is provided with three-point distributed mounting holes, which are installed on the support or bracket through fasteners; one of the mounting holes is located on the lug on the front end surface of the shell, and the other two are located on two symmetrical lugs on the rear end surface.

[0016] An application of a dual-redundant servo valve, the dual-redundant servo valve is used in an aircraft braking system, with the right valve in hot backup mode;

[0017] When there is no control current signal, the two electro-hydraulic servo valves are not activated, the oil return port of the dual-redundant servo valve is closed, the load port and the pressure supply port remain unobstructed, and hydraulic pressure is output from the load port to the hydraulic actuator; at this time, the dual-redundant servo valve is equivalent to only a section of the pipeline;

[0018] When a control current signal is received, the two electro-hydraulic servo valves are activated, the oil inlet openings of the left and right valves gradually decrease or close completely, and the oil return openings of the left and right valves gradually increase or open completely. At the same time, the load ports of the left and right valves are connected to the oil return ports of the left and right valves, and then connected to the oil return port on the housing through the oil circuit, reducing or completely relieving the load port pressure. Depending on the control current, the load ports of the left and right valves output a hydraulic pressure inversely proportional to the control current. The load port on the housing is connected to the load port of the right valve through a built-in oil circuit, and the load port on the housing outputs a hydraulic pressure corresponding to the control current.

[0019] When the two electro-hydraulic servo valves are powered on and the pressure detected by the monitoring port of the housing does not decrease, it indicates that the left valve is faulty and the control task is completed by the right valve.

[0020] When the pressure detected at the monitoring port of the shell does not decrease, and the pressure at the load port of the shell does not decrease at the same time, both the left valve and the right valve fail, and the dual-redundant servo valve fails.

[0021] An application of a dual-redundant servo valve, the dual-redundant servo valve is used in an aircraft braking system, with the right valve in cold backup mode;

[0022] When there is a control current signal, the left valve starts as the main valve, and the right valve is in the closed state as a cold backup. The left valve independently completes the control of the output hydraulic pressure; when the left valve fails, the controller sends a control current signal to the right valve, starting the right valve to complete the control task.

[0023] Beneficial effects

[0024] The beneficial effects of the present invention lie in its structural improvements to a conjoined dual valve or single dual-chamber valve, replacing independent dual valves used to control two load ports with dual valves used to control a single load port. This effectively overcomes the drawback of the existing electro-hydraulic servo valves, which are characterized by single redundancy. The dual-redundant servo valve proposed in the present invention consists of a pair of twin electro-hydraulic servo valves housed in a shared housing. The reliability model of the left and right valves in this valve system is a parallel relationship. As long as one electro-hydraulic servo valve is functioning properly, the dual-redundant servo valve can regulate and control the output pressure.

[0025] In this invention, the left valve load port is connected to the right valve load port, and the right valve load port serves as the output port for hydraulic communication with the load port of the dual-redundant servo valve. This creates a parallel reliability model for the left and right valves, and the left and right valves are identical electro-hydraulic servo valves, thus achieving a truly dual-redundant valve. The probability of simultaneous failure of both valves is minimal, thus multiplying the reliability of the dual-redundant servo valve. This significantly improves the reliability of electro-hydraulic servo valves in safety-critical applications at the expense of a moderate weight penalty, particularly preventing accidents such as aircraft brake tire blowouts.

[0026] The present invention sets a monitoring port to detect the hydraulic pressure signal of the left valve load port through a hydraulic pressure sensor, which can monitor the operating status of the dual-redundant servo valve in real time, greatly facilitating use, maintenance and troubleshooting.

[0027] The present invention has a reasonable design, excellent performance, and is simple and easy to implement. It overcomes the bottleneck problem of the electro-hydraulic servo valve control system at a relatively low cost, significantly improves the reliability of the use of electro-hydraulic servo valves in safety-critical application fields, especially the safety and reliability of aircraft electronic anti-skid control systems, and has obvious technical, economic, military and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural diagram of a double-redundant servo valve of the present invention, a pre-stage spray stop valve;

[0029] Figure 2 1 is an outline view (top view) of a dual-redundant servo valve according to embodiment 1 of the present invention;

[0030] Figure 3 This is the outline drawing of the double-redundant servo valve housing, top view;

[0031] Figure 4This is the front view of the double-redundant servo valve housing, that is, Figure 3 K direction;

[0032] Figure 5 This is the rear end view of the double redundant servo valve housing, that is, Figure 3 N direction;

[0033] Figure 6 This is a cross-sectional view of the double-redundant servo valve housing, that is, Figure 4 AA direction, the curved parts are not on the same plane;

[0034] Explanation of the accompanying symbols: 1. Housing; 2. Left valve; 3. Right valve; 4. Pressure supply port; 5. Oil return port; 6. Load port; 7. Left valve oil inlet; 8. Left valve load port; 9. Left valve oil return port; 10. Left valve pre-stage oil inlet; 11. Left valve pre-stage overflow chamber; 12. Right valve oil inlet; 13. Right valve load port; 14. Right valve oil return port; 15. Right valve pre-stage oil inlet; 16. Right valve pre-stage overflow chamber; 17. Monitoring port; 18. Hydraulic oil filter; 19. Electrical interface; 20. Mounting hole. DETAILED DESCRIPTION

[0035] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0037] This embodiment provides a dual-redundant servo valve and its application. Two electro-hydraulic servo valves are arranged in parallel in the housing of the dual-redundant servo valve. The two electro-hydraulic servo valves work together to avoid the impact of failures, or when one valve fails, the other valve is activated to work normally, ensuring the stability of the servo valve operation. It can be used in aircraft braking systems to prevent tire blowouts.

[0038] The dual-redundant servo valve includes a housing, two sets of electro-hydraulic servo valves and a hydraulic pressure sensor; the two sets of electro-hydraulic servo valves are connected in parallel and arranged in the housing, and are defined as a left valve and a right valve respectively; the hydraulic pressure of the left valve is monitored by the hydraulic pressure sensor; the left valve is set as the main valve and the right valve is set as the backup valve; when the right valve is a hot backup, the two sets of electro-hydraulic servo valves are started at the same time to control the supply pressure, and if one of them fails, the other can independently complete the control target; when the right valve is a cold backup, the backup valve is only started when the main valve fails to complete the control target.

[0039] This invention improves the structure of a conjoined dual valve or single dual-chamber valve, replacing independent dual valves used to control two load ports with a single valve designed to control a single load port. This effectively overcomes the drawback of existing electro-hydraulic servo valves, which typically only have single redundancy. The dual-redundant servo valve proposed in this invention consists of a pair of twin electro-hydraulic servo valves housed in a shared housing. The reliability model for the left and right valves of this valve system is a parallel relationship. As long as one electro-hydraulic servo valve is functioning properly, the dual-redundant servo valve can regulate and control the output pressure.

[0040] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0041] Example:

[0042] See attached Figure 1-6 A dual-redundant servo valve comprises: a housing 1, two electro-hydraulic servo valves, referred to as a left valve 2 and a right valve 3, and a hydraulic pressure sensor. The two electro-hydraulic servo valves are symmetrically arranged within the housing 1 and are integral with the housing 1, forming a conjoined dual-valve or single-body dual-chamber valve structure. Each electro-hydraulic servo valve includes a torque motor, a pre-stage, and a spool stage.

[0043] The housing is equipped with four hydraulic ports and one electrical port 19. The four hydraulic ports are the pressure supply port 4, the load port 6, the oil return port 5, and the monitoring port 17, which are hydraulically connected to the system pressure source, the hydraulic actuator, the oil tank, and the hydraulic pressure sensor, respectively. The electrical port 19 is electrically connected to the controller, which is a system component and is not shown in the figure.

[0044] The two electro-hydraulic servo valve left valve oil inlet ports 7 are hydraulically connected to the pressure supply port 4 on the housing, the two electro-hydraulic servo valve left valve load ports 8 are hydraulically connected to the two electro-hydraulic servo valve right valve oil inlet ports 12, and the two electro-hydraulic servo valve left valve oil return ports 9 are hydraulically connected to the oil return port 5 on the housing.

[0045] The two electro-hydraulic servo valve right valve oil inlet ports 12 are hydraulically connected to the two electro-hydraulic servo valve left valve load ports 8, the two electro-hydraulic servo valve right valve return oil ports 14 are hydraulically connected to the oil return port 5 on the housing, the two electro-hydraulic servo valve right valve load ports 13 are hydraulically connected to the load port 6 on the housing, and the two electro-hydraulic servo valve right valve pre-stage oil inlet ports 15 are hydraulically connected to the pressure supply port 4 on the housing.

[0046] Both electro-hydraulic servo torque motors are electrically connected to electrical port 19 on the housing. The hydraulic pressure sensor is mounted on monitoring port 17 on the housing. The hydraulic pressure sensor detects the pressure at load port 8 of the left valve. The pressure signal is fed into the controller to monitor the operating status of the left valve. Furthermore, when the right valve is in hot backup mode and the left valve fails, the controller sends a control current signal to the right valve to activate its operation. For clarity, the hydraulic pressure sensor is not shown.

[0047] Preferably, the pressure supply port 4 is provided with a hydraulic oil filter 18 to filter out oil source contaminants to prevent dirt from entering the valve. The hydraulic oil filter 18 has an accuracy of 3-15μ, and this embodiment uses a 5μ fine oil filter.

[0048] The oil passages from the pressure supply port 4 into the housing are divided into two: one passage enters the left valve oil inlet 7; the other passage enters the right valve pre-stage oil inlet 15.

[0049] The two electro-hydraulic servovalves described in this embodiment are pressure-type negative-gain valves with a single load port, used for aircraft braking. Therefore, the load port is also called the brake port. The electro-hydraulic servovalves include a torque motor, a pre-stage for the injection valve, and a spool valve power stage. These two electro-hydraulic servovalves are conventional.

[0050] The shell 1 is a flat-roofed block, which is a rectangular block cut by two symmetrical inclined planes. The upper part of the flat-roofed block is composed of two symmetrical inclined planes and a top surface. The top surface is parallel to the bottom surface, and the top surface is connected to the upper inclined plane of the side surface. The upper inclined planes on both sides are symmetrical, and the inclined plane inclination angle is 30-60°. The inclined plane inclination angle of this embodiment is 45°. The return oil port 5 is arranged on the top surface, the load port 6 is arranged on the right inclined plane, and the monitoring port 17 is arranged on the left inclined plane; the rear end surface is provided with a circular boss, and a cavity is opened in the center of the circular boss to accommodate the hydraulic oil filter 18; the pressure supply port 4 is arranged on the right inclined plane near the rear end surface; the two electro-hydraulic servo valve torque motors are symmetrically arranged on the two side surfaces, namely: the left valve torque motor is arranged on the left side, and the right valve torque motor is arranged on the right side. The two electro-hydraulic servo valve pre-stages and the slide valve are symmetrically arranged in the shell.

[0051] The oil passages and cavities in the housing 1 are processed according to existing techniques, such as drilling and milling.

[0052] The housing 1 is provided with three mounting holes 20 for fastening fasteners to a support or bracket, one of which is located at the middle lug at the bottom of the front face, and the other two are located at two symmetrical lugs at the bottom of the rear face.

[0053] In this embodiment, the valve is securely mounted on the bracket using shock-absorbing washers and self-locking bolts through three mounting holes 20 .

[0054] The diameter of the oil return port 5 is larger than that of the pressure supply port 4 , the load port 6 and the monitoring port 17 ; in this embodiment, the diameter of the oil return port 5 is 5 mm larger than that of the other oil ports.

[0055] The pressure supply port 4, load port 6, oil return port 5 and monitoring port 17 are all marked with characters to facilitate pipeline connection and prevent wrong connection. In this embodiment, they are marked P, B, R, and C respectively.

[0056] A recess is provided at the top of the rear end surface to accommodate the electrical interface 19 .

[0057] The application and operation process of a dual-redundant servo valve in this embodiment is as follows:

[0058] There are two modes: right valve as hot backup and right valve as cold backup.

[0059] The operation process of the torque motor of the left valve and the right valve and the electro-hydraulic servo valve of the pre-stage control power stage slide valve is based on the existing technology.

[0060] Mode 1: The right valve is in hot backup mode;

[0061] When there is no control current signal, the two electro-hydraulic servo valves are not activated, the return port of the dual-redundant servo valve is closed, the load port and the oil inlet remain unobstructed, and hydraulic pressure is output from the load port to the hydraulic actuator. At this time, the dual-redundant servo valve is equivalent to only a section of pipeline.

[0062] When a control current signal is received, the two electro-hydraulic servovalves are activated, gradually reducing or completely closing the oil inlet openings of the left and right valves, while gradually increasing or completely opening the oil return openings of the left and right valves. Simultaneously, the load ports of the left and right valves are connected to the oil return ports of the left and right valves, and then to the oil return ports of the dual-redundant servo valves via an oil circuit, reducing or completely relieving the load port pressure. Based on the control current, the load ports of the left and right valves output a hydraulic pressure inversely proportional to the control current. The load ports of the dual-redundant servo valves are connected to the load port of the right valve via an oil circuit, so that the load ports of the dual-redundant servo valves output a hydraulic pressure corresponding to the control current.

[0063] When the two electro-hydraulic servo valves are powered on and running, if the pressure detected by the monitoring port 17 does not decrease, it indicates that the left valve is faulty and the control task is completed by the right valve.

[0064] When the pressure detected at the control current monitoring port does not decrease, and the pressure at the load port of housing 1 does not decrease, it indicates that both the left valve and the right valve are faulty and the dual-redundant servo valve fails.

[0065] Mode 2: The right valve is in cold backup mode;

[0066] The dual-redundant servo valve can also be operated in this way: the left valve operates as the main valve, and the right valve operates as a cold backup. Only when the left valve fails, the controller sends a control current signal to the right valve to start the right valve to complete the control task.

[0067] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A dual-redundant servo valve, characterized in that: It comprises a housing, a hydraulic pressure sensor and two sets of electro-hydraulic servo valves; the two sets of electro-hydraulic servo valves are connected in parallel and arranged in the housing, and are defined as a left valve and a right valve respectively; the hydraulic pressure of the left valve is monitored by the hydraulic pressure sensor; the two electro-hydraulic servo valves each comprise a torque motor, a pre-stage and a spool stage; the oil inlet of the left valve is hydraulically connected to the pressure supply port on the housing, the load port of the left valve is hydraulically connected to the oil inlet of the right valve, the oil return port of the left valve is hydraulically connected to the oil return port on the housing, the oil inlet of the pre-stage of the left valve is hydraulically connected to the spool stage of the left valve; the oil return port of the right valve is hydraulically connected to the oil return port on the housing, the load port of the right valve is hydraulically connected to the load port on the housing, and the oil inlet of the pre-stage of the right valve is hydraulically connected to the pressure supply port on the housing; The left valve is set as the main valve, and the right valve is set as the backup valve; When the right valve is in hot backup mode, two sets of electro-hydraulic servo valves are started simultaneously to control the supply pressure. If one of them fails, the other can independently complete the control target. When there is no control current signal, the two electro-hydraulic servo valves are not started, the oil return port of the dual-redundant servo valve is closed, and the load port and the pressure supply port remain unobstructed; When there is a control current signal, the two electro-hydraulic servo valves are started, the oil inlet openings of the left and right valves are gradually closed or completely closed, and the oil return openings of the left and right valves are gradually opened or completely opened. At the same time, the load ports of the left and right valves are connected to the oil return ports of the left and right valves, and then connected to the oil return ports of the dual redundant servo valves through the oil circuit, reducing or completely releasing the load port pressure; When the right valve is a cold backup, the backup valve is activated only when the main valve fails to complete the control target.

2. The dual-redundant servo valve according to claim 1, characterized in that: The inner cavity of the housing is equipped with two sets of electro-hydraulic servo valves, and the outer wall is provided with four hydraulic interfaces and one electrical interface, which are connected to the corresponding components of the two sets of electro-hydraulic servo valves through the built-in channels on the housing wall; The four hydraulic interfaces are a pressure supply port, a load port, an oil return port, and a monitoring port, which are hydraulically connected to the system pressure source, the hydraulic actuator, the oil tank, and the hydraulic pressure sensor respectively; the electrical interface is electrically connected to the controller.

3. The dual-redundant servo valve according to claim 2, characterized in that: The shell is a flat-roofed block, which is formed by cutting a rectangular block with two symmetrical inclined planes. The upper part of the flat-roofed block is composed of a central top surface and two symmetrical inclined planes on both sides. The top surface is parallel to the bottom surface, and the inclination angle of the inclined plane is 30-60°; the oil return port is arranged on the top surface, the load port is arranged on the right inclined plane, the monitoring port is arranged on the left inclined plane, and the pressure supply port is arranged on the right inclined plane near the rear end surface; the rear end surface of the shell is provided with a circular boss, and the hydraulic oil filter is installed through the hole cavity at the center of the circular boss.

4. The dual-redundant servo valve according to claim 3, characterized in that: The two torque motors of the left valve and the right valve are respectively arranged on the two sides of the dual-redundant servo valve, that is, the left valve torque motor is arranged on the left side, and the right valve torque motor is arranged on the right side, and are respectively electrically connected to the electrical interfaces on the shell; the pre-stage and slide valve of the left valve and the right valve are symmetrically arranged on both sides of the shell.

5. The dual-redundant servo valve according to claim 4, characterized in that: The pressure supply port is provided with a hydraulic oil filter for filtering out oil source pollutants to prevent dirt from invading the valve. The hydraulic oil filter accuracy is 3-15μ.

6. The dual-redundant servo valve according to claim 5, characterized in that: The outer wall of the shell is provided with three-point distributed mounting holes, which are installed on the support or bracket through fasteners; one of the mounting holes is located on the lug on the front end surface of the shell, and the other two are located on two symmetrical lugs on the rear end surface.

7. An application of the dual-redundant servo valve according to any one of claims 1 to 6, characterized in that: The dual-redundant servo valve is used in the aircraft braking system, with the right valve in hot backup mode; When there is no control current signal, the two electro-hydraulic servo valves are not activated, the oil return port of the dual-redundant servo valve is closed, the load port and the pressure supply port remain unobstructed, and hydraulic pressure is output from the load port to the hydraulic actuator; at this time, the dual-redundant servo valve is equivalent to only a section of the pipeline; When a control current signal is received, the two electro-hydraulic servo valves are activated, the oil inlet openings of the left and right valves gradually decrease or close completely, and the oil return openings of the left and right valves gradually increase or open completely. At the same time, the load ports of the left and right valves are connected to the oil return ports of the left and right valves, and then connected to the oil return port on the housing through the oil circuit, reducing or completely relieving the load port pressure. Depending on the control current, the load ports of the left and right valves output a hydraulic pressure inversely proportional to the control current. The load port on the housing is connected to the load port of the right valve through a built-in oil circuit, and the load port on the housing outputs a hydraulic pressure corresponding to the control current. When the two electro-hydraulic servo valves are powered on and the pressure detected by the monitoring port of the housing does not decrease, it indicates that the left valve is faulty and the control task is completed by the right valve. When the pressure detected at the monitoring port of the shell does not decrease, and the pressure at the load port of the shell does not decrease at the same time, both the left valve and the right valve fail, and the dual-redundant servo valve fails.

8. An application of the dual-redundant servo valve according to any one of claims 1 to 6, characterized in that: The dual-redundant servo valve is used in the aircraft braking system, with the right valve in cold backup mode; When there is a control current signal, the left valve starts as the main valve, and the right valve is in the closed state as a cold backup. The left valve independently completes the control of the output hydraulic pressure; when the left valve fails, the controller sends a control current signal to the right valve, starting the right valve to complete the control task.

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