Permanent magnet saddle type moving iron type structure torque motor for servo valve

Abstract

The invention discloses a permanent magnet saddle type moving iron type structure torque motor for a servo valve. The permanent magnet saddle type moving iron type structure torque motor comprises magnetic steel, a magnetizer, a gap adjusting screw, an armature assembly, an armature rod, an elastic support and a baffle. The two magnetic steels and the two magnetizers are integrated together to form a closed magnetic loop; a hollow cylinder structure is designed between the two magnetizers to form a fixed magnetic gap; the armature rod is mounted in a hollow cylindrical magnetic gap space formed by the two magnetizers; the coil assembly is sleeved on the armature rod, and the magnetic field intensity and polarity of the control magnetic flux at the end of the armature rod are changed by inputting control currents with different magnitudes and directions to the coil assembly, so that the armature rod is controlled to rotate anticlockwise or clockwise, and the baffle at the lower end of the lower armature rod is driven to deflect. According to the structure, the requirement for the control precision of the size of the magnetic steel is not high, the magnetic gap is achieved through the fine-tooth magnetic gap adjusting screw, adjustment is easy and convenient, parts do not need to be disassembled and assembled repeatedly when the magnetic gap is adjusted, continuous adjustment can be achieved, part abrasion is reduced, and the service life is longer.

Description

Technical Field

[0001] This invention belongs to the field of aircraft braking technology, specifically relating to a permanent magnet saddle-type moving iron torque motor for servo valves. Background Technology

[0002] The nozzle-flange type pressure servo valve is installed in the aircraft brake control system and is the core control device of the brake control system. It can convert the control current provided by the brake control unit into a brake pressure that is proportional to it, thereby controlling the aircraft wheels to achieve braking.

[0003] Most existing pressure servo valves use a torque motor with a permanent magnet bridge-type moving iron structure to drive the armature assembly. The structure of the permanent magnet bridge-type moving iron torque motor is as follows: Figure 1 As shown, it mainly consists of a magnet, upper and lower magnetic conductors, an armature assembly, a coil assembly, a Bourdon tube, and a baffle. The upper and lower magnetic conductors are installed on the upper and lower sides of the magnet, respectively. The armature assembly is located in the middle of the upper and lower magnetic conductors. The upper and lower magnetic conductors and the four planes on both sides of the armature assembly form four magnetic gaps. During installation, the installation position of the upper and lower magnetic conductors is adjusted to ensure that the four magnetic gaps are the same, so that the electromagnetic force on the armature assembly is the same in the initial state. In the initial state, the armature assembly is held in a free state with balanced force.

[0004] The disadvantage of this structure is that the magnets on both sides have high dimensional requirements in the height direction. Strict form and position tolerances are needed to ensure that the magnetic gap surface is parallel to the rod end plane on the armature assembly after the upper and lower magnetic conductors are installed. In order to keep the magnetic gaps consistent, the position of the lower magnetic conductor is usually adjusted by an adjusting shim. However, because the magnetic gap on both sides is small in use, about 0.3mm to 0.4mm, and there are dimensional tolerances in the parts during manufacturing, the method of adjusting the magnetic gap by adjusting the magnetic gap with adjusting shims of different thicknesses has poor assembly processability. The thickness interval of the adjusting shims should be as small as possible to ensure that the magnetic gap requirements can be met by selecting shims of different thicknesses when adjusting the magnetic gap. This puts a burden on the parts manufacturing, inspection and assembly, and will greatly reduce the efficiency of product assembly. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a permanent magnet saddle-type moving iron torque motor for servo valves, comprising magnets, magnetic conductors, adjusting screws, an armature assembly, an armature rod, an elastic support, and a baffle. Two magnets and two magnetic conductors are integrated together to form a closed magnetic circuit. The space between the two magnetic conductors is designed as a hollow cylinder, forming a fixed magnetic gap. The armature rod is installed within the hollow cylindrical magnetic gap formed by the two magnetic conductors. A coil assembly is fitted onto the armature rod. By inputting control currents of different magnitudes and directions to the coil assembly, the magnetic field strength and polarity of the control flux at the end of the armature rod are changed, thereby controlling the armature rod to rotate counterclockwise or clockwise, driving the baffle on the lower end of the lower armature rod to deflect. This invention does not require high precision in controlling the magnet dimensions. The magnetic gap is adjusted using a fine-tooth adjusting screw, making adjustment simple and convenient. Adjusting the magnetic gap does not require repeated disassembly and reassembly of parts, enabling continuous adjustment, reducing wear on parts, and extending service life.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows:

[0007] A permanent magnet saddle-type moving iron torque motor for servo valves includes a magnet, a magnetic conductor, an adjusting screw, an armature assembly, an armature rod, an elastic support, and a baffle.

[0008] Two magnets and two magnetic conductors are integrated together to form a closed magnetic circuit; the magnets form a fixed magnetic flux in the magnetic circuit when they are magnetized; the two magnetic conductors are designed with a hollow cylindrical structure to form a fixed magnetic gap.

[0009] The adjusting screw is mounted on the magnetic conductor;

[0010] The armature rod is installed in the hollow cylindrical magnetic gap space formed by two magnetic conductors, dividing the original fixed magnetic gap into two. The armature rod and the N and S poles of the magnetic conductors respectively form two magnetic gaps. The size of the two magnetic gaps is controlled by the position of two adjusting screws on the magnetic conductors.

[0011] The coil assembly is fitted onto the armature rod. By inputting control currents of different magnitudes and directions into the coil assembly, the polarity of the magnetic field at the end of the armature rod is changed, thereby controlling the armature rod to rotate counterclockwise or clockwise, which in turn causes the baffle on the lower end of the lower armature rod to deflect.

[0012] The elastic support, which is installed above the armature rod baffle, is a diaphragm structure used to provide elastic force during operation.

[0013] Preferably, the magnet and the magnetic conductor are integrated together by welding.

[0014] Preferably, the magnet has a fan-shaped structure.

[0015] Preferably, the magnetic steel is a permanent magnetic material.

[0016] Preferably, the coil assembly comprises a coil skeleton and an enameled wire, and generates a control magnetic flux after being electrified to control the direction and size of the magnetic field.

[0017] Preferably, the armature rod is made of a soft magnetic material.

[0018] Preferably, the baffle is processed into two parallel end surfaces to form a variable liquid resistance together with the nozzle hole of the torque motor, and the armature rod generates a certain electromagnetic torque under the action of the superimposed magnetic field of the fixed magnetic flux and the control magnetic flux, drives the elastic support and the baffle to deflect, and the liquid resistance formed by the deflected baffle and the two side nozzles changes, thereby changing the control pressure.

[0019] Preferably, the armature rod, the elastic support and the baffle are integrated together by welding to form an armature assembly, and the armature assembly is installed on the fixed valve seat of the torque motor through two threaded holes on the installation plane of the elastic support; the torque motor remains in the initial non-electrified state, and the armature assembly remains in the mechanical installation position and is not affected by any external force; when the coil assembly is electrified with a control current of 0-40 mA, the coil on the armature rod generates a control magnetic flux conforming to the right-hand rule, and a magnetic pole related to the direction of the electrified current of the coil assembly is generated at the upper end of the armature rod; at this time, the armature rod is subjected to the superimposed action of the fixed magnetic flux and the control magnetic flux, and the armature rod is subjected to an electromagnetic thrust in the direction to the left, drives the armature assembly to rotate counterclockwise, and the elastic support diaphragm has a certain elastic effect, and the baffle welded together with the elastic support diaphragm also deflects counterclockwise; the gap formed by the deflected baffle and the nozzle end surface in the nozzle baffle servo valve changes, the left nozzle baffle gap increases, the left nozzle front end liquid resistance decreases, the pressure decreases accordingly, the right nozzle baffle gap decreases, the right nozzle front end liquid resistance increases, the pressure increases accordingly, and the pressure difference between the two sides of the nozzle front end is taken as the control cavity pressure and introduced into the spool stage to control the spool movement, and then the pilot stage control pressure difference is output after being amplified by the spool stage, at this time, the output pressure is proportional to the control current of the pilot stage torque motor, and the proportional control of the hydraulic servo valve is realized.

[0020] The beneficial effects of the present application are as follows:

[0021] The application is based on the traditional "T" type structure torque motor, and the torque motor is designed as a "1" type structure through structural design, the structure has lower requirement on the roughness of upper and lower end faces of the magnetic steel and the height direction size, and the manufacturing difficulty of the magnetic steel is reduced; meanwhile, the magnetic gap can be continuously adjusted through the gap adjusting screw installed in the magnetic conductor, the gap adjusting screw is designed as superfine thread, the debugging process of the magnetic gap is enhanced, and the magnetic gap can be continuously adjusted in a large range through the micro-advance and micro-retreat of the two side gap adjusting screws. In the traditional "T" type structure torque motor, the symmetry of the upper and lower magnetic gaps is ensured by the consistency of the height direction size of the magnetic steel, and the two magnetic steels are selected and matched before assembly to ensure the size consistency of the two magnetic steels in the same product, meanwhile, the magnetic gap adjusting is assisted by the gaskets with different thicknesses to ensure the consistency of the upper and lower magnetic gaps during debugging, and the gasket thickness and detection requirement are strict, and the manufacturing and assembly process is poor. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a torque motor structure schematic diagram of a permanent magnet bridge type moving iron structure;

[0023] Figure 2 is a torque motor structure schematic diagram of the application;

[0024] Figure 3 is a torque motor entity display diagram of the application.

[0025] The figure legend: 1 - magnetic steel; 2 - upper and lower magnetic conductors; 3 - armature rod; 4 - coil; 5 - spring tube; 6 - baffle; 7 - magnetic steel; 8 - magnetic conductor; 9 - gap adjusting screw; 10 - coil; 11 - armature rod; 12 - elastic support; 13 - baffle. DETAILED DESCRIPTION

[0026] The application will be further described below in combination with the drawings and examples.

[0027] The application provides a permanent magnet saddle type moving iron structure torque motor, as shown in the drawings. Figure 2 The saddle type torque motor structure includes a magnetic steel 7, a magnetic conductor 8, a gap adjusting screw 9, a coil assembly 10, an armature rod 11, an elastic support 12 and a baffle 13. Two magnetic steels 7 and two magnetic conductors 8 are integrated together through welding to form a closed magnetic loop, the magnetic steel 7 forms a fixed magnetic flux in the magnetic loop in the magnetized state, and the magnetic field direction and magnetic pole are as shown in the drawings. Figure 2As shown, the two magnetic conductors 8 are designed as hollow cylindrical structures to form a fixed magnetic gap, and the armature rod 11 is installed in the hollow cylindrical magnetic gap space formed by the two magnetic conductors 8, thereby dividing the original fixed magnetic gap into two. The armature rod 11 and the N and S poles of the magnetic conductors 8 form two magnetic gaps, respectively. The size of the two magnetic gaps can be controlled by the positions of the two gap adjusting screws 9 on the magnetic conductors 8. The coil assembly 10 is sleeved on the armature rod 11. By inputting control currents of different sizes and directions to the coil assembly 10, the polarity of the magnetic field at the end of the armature rod 11 can be changed. With different sizes and directions of the control current, the size and direction of the electromagnetic force generated at the end of the armature rod 11 change, thereby controlling the armature rod to rotate counterclockwise or clockwise, thereby driving the deflector 13 at the lower end of the lower armature rod to deflect. After the deflector deflects, the gap between the deflector and the nozzle changes to change the fluid resistance, thereby achieving pressure control. The structure has low control precision requirements for the size of the magnetic steel. The magnetic gap is adjusted by the fine tooth magnetic gap adjusting screw, which is simple and convenient to adjust. When adjusting the magnetic gap, the parts do not need to be repeatedly disassembled and assembled, the wear of the parts is reduced, and the service life is longer.

[0028] The magnetic steel 7 is a permanent magnetic material with high coercive force. The magnetic steel 7 appears in pairs in the torque motor assembly of the servo valve, has stable magnetic properties after magnetization, and is mainly used to provide a fixed magnetic field as a magnetic field source during product operation. The magnetic conductor 8 is a soft magnetic material with high magnetic conductivity, and together with the magnetic steel 7 forms a closed loop with low magnetic resistance. The gap adjusting screw 9 is installed in the magnetic conductor through a thread, and the magnetic gap formed by the two magnetic conductors in the two magnetic loops can be adjusted by adjusting the amount of the gap adjusting screw 9, thereby changing the magnetic field strength at the magnetic gap. The coil assembly 10 is mainly composed of a coil skeleton and an enameled wire, and its main function is to generate a control magnetic flux after being electrified. The direction and size of the control magnetic field are related to the direction and size of the electrified current. The armature rod 11 is made of a soft magnetic material and is installed at the center position of the annular magnetic gap region formed by the magnetic conductor 8. After the fixed magnetic flux and the control magnetic flux jointly act, the end of the armature rod is driven to deflect together with the elastic support 12 and the deflector 13 under the action of the electromagnetic torque. The elastic support 12 is a long-life element with certain high elasticity and fatigue resistance, which is installed on the integrated valve seat plane through a screw. The general structure is designed as a diaphragm structure, which provides certain small deformation during operation and balances the electromagnetic torque at the end of the armature rod 11 and the hydraulic torque at the deflector 12, respectively. The deflector 13 is processed into two parallel end faces, which together with the nozzle hole form a variable liquid resistance. Under the action of the superimposed magnetic field of the fixed magnetic flux and the control magnetic flux, the armature rod generates a certain electromagnetic torque, which drives the elastic support and the deflector to deflect. After the deflector deflects, the liquid resistance formed by the deflector and the nozzles on both sides changes, thereby changing the control pressure.

[0029] Embodiment:

[0030] As Figure 2 and Figure 3As shown, before assembly, the magnet assembly (including 2 magnetic steel 7 and 2 magnetic conductors 8) is magnetized according to special technical requirements, and a fixed magnetic field is generated in the magnetic loop formed by the magnet assembly, as shown Figure 2 As shown, the left side is S pole, and the right side is N pole; the armature rod 11, the elastic support 12 and the baffle 13 are integrated by welding to form an armature assembly (including an armature rod, an elastic support and a baffle), which is installed on the fixed valve seat through two threaded holes on the installation plane of the elastic support, and after installation, the armature rod 11 is located in the loop formed by the magnet assembly, and the armature rod is divided into two magnetic gaps formed by the two magnetic conductors through structural design and assembly tooling, at this time, the armature rod is kept in the initial installation position without moving, and an coil assembly (mainly including coil skeleton and enameled wire) is installed between the elastic support 12 and the armature rod 11. The armature assembly remains in the mechanical installation position without being affected by any external force (the electromagnetic torque generated by the two magnetic gaps is equal in size and opposite in direction, and they cancel each other out) in the initial non-powered state of the torque motor; when the coil assembly is connected with a control current of 0-40mA, the coil on the armature rod will generate a control magnetic flux conforming to the right-hand rule, and a magnetic pole related to the direction of the current of the coil assembly will be generated at the upper end of the armature rod (at the magnetic gap), as shown Figure 2 As shown, the left side is S pole, and the right side is N pole; the armature rod 11, the elastic support 12 and the baffle 13 are integrated by welding to form an armature assembly (including an armature rod, an elastic support and a baffle), which is installed on the fixed valve seat through two threaded holes on the installation plane of the elastic support, and after installation, the armature rod 11 is located in the loop formed by the magnet assembly, and the armature rod is divided into two magnetic gaps formed by the two magnetic conductors through structural design and assembly tooling, at this time, the armature rod is kept in the initial installation position without moving, and an coil assembly (mainly including coil skeleton and enameled wire) is installed between the elastic support 12 and the armature rod 11. The armature assembly remains in the mechanical installation position without being affected by any external force (the electromagnetic torque generated by the two magnetic gaps is equal in size and opposite in direction, and they cancel each other out) in the initial non-powered state of the torque motor; when the coil assembly is connected with a control current of 0-40mA, the coil on the armature rod will generate a control magnetic flux conforming to the right-hand rule, and a magnetic pole related to the direction of the current of the coil assembly will be generated at the upper end of the armature rod (at the magnetic gap), as shown As shown, the left side is S pole, and the right side is N pole; the armature rod 11, the elastic support 12 and the baffle 13 are integrated by welding to form an armature assembly (including an armature rod, an elastic support and a baffle), which is installed on the fixed valve seat through two threaded holes on the installation plane of the elastic support, and after installation, the armature rod 11 is located in the loop formed by the magnet assembly, and the armature rod is divided into two magnetic gaps formed by the two magnetic conductors through structural design and assembly tooling, at this time, the armature rod is kept in the initial installation position without moving, and an coil assembly (mainly including coil skeleton and enameled wire) is installed between the elastic support 12 and the armature rod 11. The armature assembly remains in the mechanical installation position without being affected by any external force (the electromagnetic torque generated by the two magnetic gaps is equal in size and opposite in direction, and they cancel each other out) in the initial non-powered state of the torque motor; when the coil assembly is connected with a control current of 0-40mA, the coil on the armature rod will generate a control magnetic flux conforming to the right-hand rule, and a magnetic pole related to the direction of the current of the coil assembly will be generated at the upper end of the armature rod (at the magnetic gap), as shown

Claims

1. A permanent magnet saddle type moving iron structure torque motor for a servo valve, characterized by, Magnetic steel, magnetic conductor, gap adjusting screw, armature assembly, armature rod, elastic support and baffle Two magnetic steels and two magnetic conductors are integrated together to form a closed magnetic circuit; the magnetic steel forms a fixed magnetic flux in the magnetic circuit in the magnetized state; the two magnetic conductors are designed as hollow cylindrical structures to form a fixed magnetic gap; The gap adjusting screw is installed on the magnetic conductor; The armature rod is installed in the hollow cylindrical magnetic gap space formed by the two magnetic conductors to divide the original fixed magnetic gap into two, and the armature rod and the N and S poles of the magnetic conductor form two magnetic gaps, respectively, and the size of the two magnetic gaps is controlled by the positions of the two gap adjusting screws on the magnetic conductor; The coil assembly is sleeved on the armature rod, and the polarity of the magnetic field at the end of the armature rod is changed by inputting control current of different sizes and directions to the coil assembly, so as to control the armature rod to rotate counterclockwise or clockwise, and drive the baffle on the lower end of the armature rod to deflect; The elastic support is installed above the baffle of the armature rod and is in a diaphragm structure to provide elastic force during operation.

2. A permanent-magnet saddle-type moving-iron structure torque motor for a servo valve according to claim 1, characterized by The magnetic steel and the magnetic conductor are integrated together by welding.

3. A permanent-magnet saddle-type moving-iron torque motor for a servo valve according to claim 1, characterized by The magnetic steel is in a fan structure.

4. A permanent-magnet saddle-type moving-iron torque motor for a servo valve according to claim 1, characterized by The magnetic steel is a permanent magnetic material.

5. A permanent-magnet saddle-type moving-iron torque motor for a servo valve according to claim 1, characterized by The coil assembly includes a coil framework and an enameled wire, and generates a control magnetic flux after being energized to control the direction and size of the magnetic field.

6. A permanent-magnet saddle-type moving-iron torque motor for a servo valve according to claim 1, characterized by The armature rod is made of soft magnetic material.

7. A permanent-magnet saddle-type moving armature torque motor for a servo valve according to claim 1, characterized by The baffle is processed into two parallel end faces to form a variable liquid resistance together with the nozzle hole of the torque motor, and the armature rod generates a certain electromagnetic torque under the superimposed magnetic field of the fixed magnetic flux and the control magnetic flux, drives the elastic support and the baffle to deflect, and changes the liquid resistance formed by the baffle and the nozzles on both sides after deflection, thereby changing the control pressure.

8. A permanent-magnet saddle-type moving armature torque motor for a servo valve according to claim 1, characterized by The armature rod, the elastic support and the baffle are integrated together by welding to become an armature assembly, and the armature assembly is installed on the fixed valve seat of the torque motor through the two threaded holes on the installation plane of the elastic support; the torque motor is in an initial non-energized state, the armature assembly remains in the mechanical installation position and is not affected by any external force; when the coil assembly is energized with a control current of 0-40 mA, the coil on the armature rod will generate a control magnetic flux conforming to the right-hand rule, and a magnetic pole related to the direction of the current of the coil assembly is generated at the upper end of the armature rod; at this time, the armature rod is subjected to an electromagnetic thrust to the left under the superimposed action of the fixed magnetic flux and the control magnetic flux, drives the armature assembly to rotate counterclockwise, and the elastic support diaphragm exerts a certain elastic force, and the baffle welded thereto also deflects counterclockwise; the gap formed by the baffle and the nozzle end face in the nozzle baffle servo valve changes after the deflection of the two planes of the baffle, the left nozzle baffle gap increases, the liquid resistance in front of the left nozzle decreases, the pressure decreases accordingly, the right nozzle baffle gap decreases, the liquid resistance in front of the right nozzle increases, the pressure increases accordingly, and the pressure difference between the front ends of the two nozzles serves as the control cavity pressure, is introduced into the spool stage to control the spool movement, and then the pilot stage control pressure difference is amplified by the spool stage and output, at this time, the output pressure is proportional to the control current of the pilot stage torque motor, and proportional control of the hydraulic servo valve is realized.

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