A torque motor with adjustable air gap and its online air gap adjustment method

Abstract

The present invention discloses a torque motor with adjustable air gap and its online air gap adjustment method, which relates to the field of electro-hydraulic servo valves and can realize online independent or combined multi-method adjustment of the sizes of four working air gaps, thereby changing the null position and gain of the servo valve and improving the null position stability of the servo valve. The torque motor with adjustable air gap includes: an armature assembly, a magnetic circuit assembly, and an air gap adjuster; by adjusting the movable pole shoe in the air gap adjuster through threads, the increase or decrease of the four working air gaps is realized, so as to achieve the purpose of null position adjustment and gain improvement.

Description

Technical Field

[0001] The present invention relates to the technical field of electro-hydraulic servo valve torque motors, and particularly relates to a torque motor with adjustable air gap and an on-line air gap adjustment method thereof. Background Art

[0002] An electro-hydraulic servo valve is a highly symmetric hydraulic amplification component that converts a tiny signal into power output, and is widely used in electro-hydraulic servo control systems in fields such as aviation, aerospace, and navigation. Its structural composition mainly includes a pre-stage and a spool stage. The pre-stage provides drive for the spool stage, and the pre-stage consists of a torque motor and a hydraulic amplifier. Among them, the most influential factor on the output performance of the torque motor is the size of the four working air gaps. In an ideal state, the four air gaps are completely symmetric and equal. However, due to machining errors, screw pre-tightening assembly errors, and the influence of high and low temperature environments, in fact, the four air gaps are not completely equal and symmetric, resulting in abnormal zero bias of the servo valve, which seriously affects the stability of the servo valve. At present, there is no related torque motor structure that can individually adjust the size of the four air gaps online; in the traditional structural design of electro-hydraulic servo valve torque motors, square pole shoes are used. When adjusting the air gap, usually two adjustment shims are added between the lower magnetic conductor and the housing to adjust the size of the four air gaps; during the adjustment process, when increasing or decreasing the adjustment shim on any one side, the size of the lower air gap on this side will decrease or increase, and the size of the upper air gap will increase or decrease, showing a differential movement mode, and it is impossible to individually adjust the size of the four air gaps, and it is impossible to make the air gap sizes on the left and right sides completely consistent. Summary of the Invention

[0003] In order to solve the above problems, the object of the present invention is to provide a torque motor with adjustable air gap and an on-line air gap adjustment method thereof. An air gap adjuster is provided at the four air gaps of the torque motor, and the size of the air gap can be adjusted by multiple methods online.

[0004] To achieve the above object, the torque motor with adjustable air gap provided by the present invention adopts the following technical solutions:

[0005] A torque motor with adjustable air gap includes: an upper magnetic conductor, an armature, a support tube, a spring tube, a lower magnetic conductor, a mounting seat, a first permanent magnet, a second permanent magnet, a first torque motor screw, a second torque motor screw, a third torque motor screw, a fourth torque motor screw, a first air gap adjuster, a second air gap adjuster, a third air gap adjuster, a fourth air gap adjuster, a first spring tube screw, and a second spring tube screw;

[0006] The middle inner hole of the armature is interference-fitted with the support, the step root of the support tube is interference-fitted with the inner hole of the spring tube, the spring tube is fastened to the mounting seat by a first spring tube screw and a second spring tube screw, the mounting seat is also provided with a lower magnet, the upper surface of the lower magnet is mounted with a first magnetic steel and a second magnetic steel, the upper surface of the first magnetic steel and the second magnetic steel is mounted with an upper magnet, the upper magnet, the first magnetic steel, the second magnetic steel and the lower magnet are fastened by a first torque motor screw, a second torque motor screw, a third torque motor screw and a fourth torque motor screw to form a magnetic circuit assembly, the upper magnet, the armature and the lower magnet form four working air gaps;

[0007] The first air gap adjuster, the second air gap adjuster, the third air gap adjuster, and the fourth air gap adjuster have the same structure and all include a movable pole shoe and a hexagonal pre-tightening nut. The hexagonal pre-tightening nut is used to lock the movable pole shoe adjusted into place.

[0008] Furthermore, the movable pole shoe has a stepped cylindrical shape with a threaded surface for fixing in the upper and lower magnetic conductors, a hexagonal countersunk hole is provided on the top to facilitate tool insertion and rotation, and a movable pole shoe surface is provided at the bottom;

[0009] Furthermore, the upper magnetic conductor is completely symmetrical on both sides, and the upper left pole shoe surface and the upper right pole shoe surface are circular, so as to ensure that the relative area of the movable pole shoe surface to the upper left pole shoe surface and the upper right pole shoe surface remains unchanged during the rotation adjustment process, and a threaded hole is provided in the center of the upper left pole shoe surface and a threaded hole is provided in the center of the upper right pole shoe surface for mounting the movable pole shoe;

[0010] Furthermore, the lower magnetic conductor is completely symmetrical on both sides, and the left lower pole shoe surface and the right lower pole shoe surface are circular, so as to ensure that the relative area of the movable pole shoe surface to the left lower pole shoe surface and the right lower pole shoe surface remains unchanged during the rotation adjustment process, and a threaded hole is provided in the center of the left lower pole shoe surface and a threaded hole is provided in the center of the right lower pole shoe surface for mounting the movable pole shoe;

[0011] Furthermore, the outer diameters of the left upper pole shoe surface, the right upper pole shoe surface, the left lower pole shoe surface, the right lower pole shoe surface and the movable pole shoe surface are the same;

[0012] Furthermore, the left and right ends of the armature are completely symmetrical, and are provided with an upper working circular surface and a lower working circular surface with the same outer diameter, and the outer diameter is slightly smaller than the movable pole shoe surface;

[0013] Furthermore, the material of the movable pole shoe and the hexagonal pre-tightening nut is consistent with that of the upper and lower magnetic conductors, and is a magnetic conductive material;

[0014] Furthermore, the present invention also discloses an online air gap adjustment method for a torque motor with adjustable air gap, and the specific operating steps are as follows:

[0015] (1) When the pre-stage of the servo valve is at the initial zero position, the pressure in the left receiving cavity of the first-stage seat is higher than that in the right receiving cavity;

[0016] S1.1: Individually adjust the first air-gap regulator or the fourth air-gap regulator. First, loosen the pre-tightening nut, and rotate the movable pole shoe through an Allen wrench so that the surface of the movable pole shoe moves upward. Observe the pressure change in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut.

[0017] S1.2: Individually adjust the second air-gap regulator or the third air-gap regulator. First, loosen the pre-tightening nut, and rotate the movable pole shoe through an Allen wrench so that the surface of the movable pole shoe moves downward. Observe the pressure change in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut.

[0018] S1.3: Combined adjustment, a combination of two, three, or four of the adjustment methods in S1.1 and S1.2;

[0019] (2) When the pre-stage of the servo valve is at the initial zero position, the pressure in the left receiving cavity of the first-stage seat is lower than that in the right receiving cavity;

[0020] S2.1: Individually adjust the first air-gap regulator or the fourth air-gap regulator. First, loosen the pre-tightening nut, and rotate the movable pole shoe through an Allen wrench so that the surface of the movable pole shoe moves downward. Observe the pressure change in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut.

[0021] S2.2: Individually adjust the second air-gap regulator or the third air-gap regulator. First, loosen the pre-tightening nut, and rotate the movable pole shoe through an Allen wrench so that the surface of the movable pole shoe moves upward. Observe the pressure change in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut.

[0022] S2.3: Combined adjustment, a combination of two, three, or four of the adjustment methods in S2.1 and S2.2;

[0023] (3) It is necessary to increase the flow rate or pressure gain of the servo valve;

[0024] S3.1: Simultaneously adjust the first air-gap regulator and the second air-gap regulator so that the surface of the movable pole shoe moves upward or downward by the same distance, making the upper air gap not equal to the lower air gap;

[0025] S3.2: Simultaneously adjust the third air-gap regulator and the fourth air-gap regulator so that the surface of the movable pole shoe moves upward or downward by the same distance, making the lower air gap not equal to the upper air gap.

[0026] The present invention has the following advantages compared with the existing torque motor structure:

[0027] (1) Adjust the air gap of the torque motor in an online multiple-way combination to compensate for the zero-position drift of the servo valve caused by factors such as manufacturing, assembly, and environment;

[0028] (2) The online method improves the flow rate or pressure gain of the servo valve, providing a new method for increasing the gain. Description of the Drawings

[0029] Figure 1 It is a front view of the torque motor;

[0030] Figure 2 It is a top view of the torque motor;

[0031] Figure 3 It is a schematic diagram of the movable pole shoe;

[0032] Figure 4 It is a schematic diagram of the upper magnetic conductor;

[0033] Figure 5 It is a schematic diagram of the lower magnetic conductor;

[0034] Figure 6 It is a schematic diagram of the armature. Detailed Implementation Manner

[0035] In order to more intuitively and clearly describe the structural principle and working method in the embodiments of the present invention, the following will introduce the embodiments in combination with the relevant drawings. The drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] The embodiments of the present invention provide a torque motor with adjustable air gaps. Through structural innovation, air gap regulators are provided at the left and right pole shoe positions of the upper magnetic conductor and the lower magnetic conductor, and the four working air gaps can be adjusted by multiple methods to compensate for the unevenness of the four air gaps caused by machining tolerances, errors, and assembly errors, improving the zero position stability of the servo valve.

[0037] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0038] A torque motor with adjustable air gaps, as Figure 1 、 2 shown, includes: upper magnetic conductor 4, armature 6, support tube 5, spring tube 10, lower magnetic conductor 8, mounting seat 7, first permanent magnet 3, second permanent magnet 9, first torque motor screw 11, second torque motor screw 13, third torque motor screw 14, fourth torque motor screw 16, first air gap regulator A, second air gap regulator B, third air gap regulator C, fourth air gap regulator D, first spring tube screw 12, second spring tube screw 15;

[0039] The inner hole in the middle of the armature 6 is in interference fit with the support tube 5. The root of the step of the support tube 5 is installed in the inner hole of the spring tube 10 by interference. The spring tube 10 is fastened to the mounting seat 7 by the first spring tube screw 12 and the second spring tube screw 15. A lower magnetic conductor 8 is also installed on the mounting seat 7. The first magnet 3 and the second magnet 9 are installed on the upper surface of the lower magnetic conductor 8. The upper magnetic conductor 4 is installed on the upper surfaces of the first magnet 3 and the second magnet 9. The upper magnetic conductor 4, the first magnet 3, the second magnet 9 and the lower magnetic conductor 8 are fastened by the first torque motor screw 11, the second torque motor screw 13, the third torque motor screw 14 and the fourth torque motor screw 16 to form a magnetic circuit assembly. The upper magnetic conductor 4, the armature 6 and the lower magnetic conductor 8 form four working air gaps;

[0040] The first air gap regulator A, the second air gap regulator B, the third air gap regulator C and the fourth air gap regulator D have exactly the same structure, and each includes a movable pole shoe 1 and a hexagonal pre-tightening nut 2. The function of the hexagonal pre-tightening nut 2 is to lock the movable pole shoe 1 in place after adjustment;

[0041] As Figure 3 shown, the outer shape of the movable pole shoe 1 is a stepped cylinder. The surface 1.1 is a thread for fixing in the upper magnetic conductor 4 and the lower magnetic conductor 8. A hexagonal counterbore is provided at the top to facilitate the insertion of a tool for rotation, and a movable pole shoe surface 1.3 is provided at the bottom end;

[0042] As Figure 4 shown, the upper magnetic conductor 4 is completely symmetric left and right. The upper left pole shoe surface 4.2 and the upper right pole shoe surface 4.4 are circular to ensure that the relative area between the movable pole shoe surface 1.3 of the movable pole shoe 1 and the upper left pole shoe surface 4.2 and the upper right pole shoe surface 4.4 remains unchanged during the rotation adjustment process. A threaded hole 4.1 is provided in the center of the upper left pole shoe surface 4.2, and a threaded hole 4.3 is provided in the center of the upper right pole shoe surface 4.4 for installing the movable pole shoe 1;

[0043] As Figure 5 shown, the lower magnetic conductor 8 is completely symmetric left and right. The lower left pole shoe surface 8.2 and the lower right pole shoe surface 8.4 are circular to ensure that the relative area between the movable pole shoe surface 1.3 of the movable pole shoe 1 and the lower left pole shoe surface 8.2 and the lower right pole shoe surface 8.4 remains unchanged during the rotation adjustment process. A threaded hole 8.1 is provided in the center of the lower left pole shoe surface 8.2, and a threaded hole 8.3 is provided in the center of the lower right pole shoe surface 8.4 for installing the movable pole shoe 1;

[0044] The outer diameters of the upper left pole shoe surface 4.2, the upper right pole shoe surface 4.4, the lower left pole shoe surface 8.2, the lower right pole shoe surface 8.4 and the movable pole shoe surface 1.3 are the same;

[0045] As Figure 6As shown, the left and right ends of the armature 6 are completely symmetrical, and are provided with an upper working circular surface 6.1 and a lower working circular surface 6.2 with the same outer diameter, and the outer diameter is slightly smaller than the active pole shoe surface 1.3;

[0046] The materials of the active pole shoe 1 and the hexagonal pre-tightening nut 2 are the same as those of the upper magnetic conductor 4 and the lower magnetic conductor 8, and are magnetic conductive materials;

[0047] The present invention also discloses a method for adjusting a torque motor with adjustable air gap, and the specific operation steps are as follows:

[0048] (1) When the pre-stage of the servo valve is at the initial zero position, the pressure in the left receiving cavity of the first-stage seat is higher than the pressure in the right receiving cavity;

[0049] S1.1: Adjust the first air gap regulator A or the fourth air gap regulator D alone. First, loosen the pre-tightening nut 2, and rotate the active pole shoe 1 through an inner hexagon wrench so that the active pole shoe surface 1.3 moves upward. Observe the pressure changes in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut 2.

[0050] S1.2: Adjust the second air gap regulator B or the third air gap regulator C alone. First, loosen the pre-tightening nut 2, and rotate the active pole shoe 1 through an inner hexagon wrench so that the active pole shoe surface 1.3 moves downward. Observe the pressure changes in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut 2.

[0051] S1.3: Combined adjustment, two, three, or four combinations of the adjustment methods in Method 1 and Method 2;

[0052] (2) When the pre-stage of the servo valve is at the initial zero position, the pressure in the left receiving cavity of the first-stage seat is lower than the pressure in the right receiving cavity;

[0053] S2.1: Adjust the first air gap regulator A or the fourth air gap regulator D alone. First, loosen the pre-tightening nut 2, and rotate the active pole shoe 1 through an inner hexagon wrench so that the active pole shoe surface 1.3 moves downward. Observe the pressure changes in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut 2.

[0054] S2.2: Adjust the second air gap regulator B or the third air gap regulator C alone. First, loosen the pre-tightening nut 2, and rotate the active pole shoe 1 through an inner hexagon wrench so that the active pole shoe surface 1.3 moves upward. Observe the pressure changes in the two cavities until the pressures are equal, and then pre-tighten the pre-tightening nut 2.

[0055] S2.3: Combined adjustment, two, three, or four combinations of the adjustment methods in S2.1 and S2.2;

[0056] (3) It is necessary to increase the flow rate or pressure gain of the servo valve;

[0057] S3.1: Adjust the first air gap regulator A and the second air gap regulator B simultaneously, so that the movable pole shoe surface 1.3 moves upward or downward by the same distance, making the upper air gap not equal to the lower air gap;

[0058] S3.2: Adjust the third air gap regulator C and the fourth air gap regulator D simultaneously, so that the movable pole shoe surface 1.3 moves upward or downward by the same distance, making the lower air gap not equal to the upper air gap.

[0059] When adjusting the flow rate or pressure gain, the qualified rate of the adjustment is determined by the pressure-flow curve of the servo valve.

[0060] Compared with the existing torque motor structure, the present invention has the following advantages:

[0061] (1) Adjust the air gap of the torque motor in an online manner by combining multiple methods to compensate for the zero position drift of the servo valve caused by factors such as manufacturing, assembly, and environment;

[0062] (2) Improve the flow rate or pressure gain of the servo valve online, providing a new method for increasing the gain.

[0063] The present invention has been described in detail above in combination with the drawings of the specification or specific implementation cases. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described and these examples should not be construed as limited to the examples set forth herein. On the contrary, these examples are described so that the positive effects of the present invention are more evident. Those not elaborated in detail in the text are regarded as well-known techniques or conventional technical means in the art.

Claims

1. A torque motor with adjustable air gap, characterized in that, Including: Upper magnetic conductor (4), armature (6), support tube (5), bellows (10), lower magnetic conductor (8), mounting base (7), first permanent magnet (3), second permanent magnet (9), first torque motor screw (11), second torque motor screw (13), third torque motor screw (14), fourth torque motor screw (16), first air-gap regulator (A), second air-gap regulator (B), third air-gap regulator (C), fourth air-gap regulator (D), first bellows screw (12), second bellows screw (15); The inner hole in the middle of the armature (6) has an interference fit with the support tube (5). The root of the step of the support tube (5) is installed with an interference fit in the inner hole of the bellows (10). The bellows (10) is fastened to the mounting base (7) by the first bellows screw (12) and the second bellows screw (15). The lower magnetic conductor (8) is also installed on the mounting base (7). The first permanent magnet (3) and the second permanent magnet (9) are installed on the upper surface of the lower magnetic conductor (8). The upper magnetic conductor (4) is installed on the upper surfaces of the first permanent magnet (3) and the second permanent magnet (9). The upper magnetic conductor (4), the first permanent magnet (3), the second permanent magnet (9) and the lower magnetic conductor (8) are fastened by the first torque motor screw (11), the second torque motor screw (13), the third torque motor screw (14) and the fourth torque motor screw (16) to form a magnetic circuit assembly. The upper magnetic conductor (4), the armature (6) and the lower magnetic conductor (8) form four working air gaps; The first air-gap regulator (A), the second air-gap regulator (B), the third air-gap regulator (C) and the fourth air-gap regulator (D) have exactly the same structure, and each includes a movable pole shoe (1) and a hexagonal pre-tightening nut (2). The function of the hexagonal pre-tightening nut (2) is to lock the movable pole shoe (1) in place after adjustment; The outer shape of the movable pole shoe (1) is a stepped cylinder. The surface (1.1) is threaded for fixing in the upper magnetic conductor (4) and the lower magnetic conductor (8). A hexagonal counterbore is provided at the top, and a movable pole shoe surface (1.3) is provided at the bottom end; The upper magnetic conductor (4) is completely symmetrical left and right. The upper left pole shoe surface (4.2) and the upper right pole shoe surface (4.4) are circular to ensure that the relative area between the movable pole shoe surface (1.3) of the movable pole shoe (1) and the upper left pole shoe surface (4.2) and the upper right pole shoe surface (4.4) remains unchanged during the rotation adjustment process. A threaded hole (4.1) is provided in the center of the upper left pole shoe surface (4.2), and a threaded hole (4.3) is provided in the center of the upper right pole shoe surface (4.4) for installing the movable pole shoe (1); The lower magnetic conductor (8) is completely symmetrical left and right. The lower left pole shoe surface (8.2) and the lower right pole shoe surface (8.4) are circular to ensure that the relative area between the movable pole shoe surface (1.3) of the movable pole shoe (1) and the lower left pole shoe surface (8.2) and the lower right pole shoe surface (8.4) remains unchanged during the rotation adjustment process. A threaded hole (8.1) is provided in the center of the lower left pole shoe surface (8.2), and a threaded hole (8.3) is provided in the center of the lower right pole shoe surface (8.4) for installing the movable pole shoe (1); The materials of the movable pole shoe (1) and the hexagonal pre-tightening nut (2) are the same as those of the upper magnetic conductor (4) and the lower magnetic conductor (8), and are all magnetic conductive materials.

2. The torque motor with adjustable air gap according to claim 1, wherein The outer diameters of the upper left pole shoe surface (4.2), the upper right pole shoe surface (4.4), the lower left pole shoe surface (8.2), the lower right pole shoe surface (8.4) and the movable pole shoe surface (1.3) are the same.

3. The torque motor with adjustable air gap according to claim 1, wherein The left and right ends of the armature (6) are completely symmetrical, and are provided with an upper working circular surface (6.1) and a lower working circular surface (6.2) with the same outer diameter. The outer diameters of the upper working circular surface (6.1) and the lower working circular surface (6.2) are slightly smaller than the outer diameter of the movable pole shoe surface (1.3).

4. An on-line adjustment method for the air gap of a torque motor with adjustable air gap, which uses a torque motor with adjustable air gap as described in any one of claims 1-3, characterized in that, It includes an air gap adjustment method for various working conditions, and the specific operation steps are as follows: (1) When the pre-stage of the servo valve is at the initial zero position, the pressure in the left receiving chamber of the first-stage seat is higher than the pressure in the right receiving chamber; S1.1: Adjust the first air gap regulator (A) or the fourth air gap regulator (D) alone. First, loosen the hexagonal pre-tightening nut (2), and rotate the movable pole shoe (1) through an internal hexagonal wrench so that the movable pole shoe surface (1.3) moves upward. Observe the pressure changes in the two chambers until the pressures are equal, and then pre-tighten the hexagonal pre-tightening nut (2). S1.2: Adjust the second air gap regulator (B) or the third air gap regulator (C) alone. First, loosen the hexagonal pre-tightening nut (2), and rotate the movable pole shoe (1) through an internal hexagonal wrench so that the movable pole shoe surface (1.3) moves downward. Observe the pressure changes in the two chambers until the pressures are equal, and then pre-tighten the hexagonal pre-tightening nut (2). S1.3: Combined adjustment, any two, three or four combinations of the adjustment methods in S1.1 and S1.2 are combined for adjustment; (2) When the pre-stage of the servo valve is at the initial zero position, the pressure in the left receiving chamber of the first-stage seat is lower than the pressure in the right receiving chamber; S2.1: Adjust the first air gap regulator (A) or the fourth air gap regulator (D) alone. First, loosen the hexagonal pre-tightening nut (2), and rotate the movable pole shoe (1) through an internal hexagonal wrench so that the movable pole shoe surface (1.3) moves downward. Observe the pressure changes in the two chambers until the pressures are equal, and then pre-tighten the hexagonal pre-tightening nut (2). S2.2: Adjust the second air gap regulator (B) or the third air gap regulator (C) alone. First, loosen the hexagonal pre-tightening nut (2), and rotate the movable pole shoe (1) through an internal hexagonal wrench so that the movable pole shoe surface (1.3) moves upward. Observe the pressure changes in the two chambers until the pressures are equal, and then pre-tighten the hexagonal pre-tightening nut (2). S2.3: Combined adjustment, any two, three or four combinations of the adjustment methods in S2.1 and S2.2 are combined for adjustment; (3) It is necessary to increase the flow rate or pressure gain of the servo valve; S3.1: Adjust the first air gap regulator (A) and the second air gap regulator (B) simultaneously, so that the movable pole shoe surface (1.3) moves upward or downward by the same distance, so that the upper air gap is not equal to the lower air gap; S3.2: Adjust the third air gap regulator (C) and the fourth air gap regulator (D) simultaneously, so that the movable pole shoe surface (1.3) moves upward or downward by the same distance, so that the lower air gap is not equal to the upper air gap.

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