A device and method for testing the natural frequencies of different modes of a servo valve armature assembly

Abstract

This invention belongs to the field of mechanical hydraulics and discloses a device and method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve. The armature assembly is mounted on a lower magnetic conductor, which has a through hole in the middle for mounting and fixing a spring tube for the armature assembly. The two armature ends of the armature assembly extend from the left and right ends above the lower magnetic conductor. Magnets are provided above the front and rear ends of the lower magnetic conductor, and an upper magnetic conductor is provided between the two magnets, forming a magnetic path with the upper magnetic conductor, the lower magnetic conductor, and the magnets. A coil is provided on the outside of the armature within the range of the lower magnetic conductor, and pole shoes are provided on the part of the armature end of the armature assembly that extends beyond the coil. The pole shoes are connected to the upper magnetic conductor or the lower magnetic conductor respectively. This invention forms a uniform and stable magnetic field on the side arc surface of the armature, thereby exerting circumferential rotational or lateral bending forces on the side of the armature, overcoming the deficiency of existing tests that can only measure the natural frequency under the axial bending mode. At the same time, it can change the force state of the armature, thereby testing the natural frequencies of the armature assembly under multiple modes.

Description

Technical Field

[0001] This invention belongs to the field of mechanical hydraulics and relates to a device and method for testing the natural frequency of an armature assembly, specifically a device and method for testing the natural frequency of a servo valve armature assembly under different modes. Background Technology

[0002] As the core hydraulic amplification component of electro-hydraulic servo valves, the armature assembly is widely used in various servo valve products. Its natural frequency directly affects the performance of the armature assembly, which in turn directly affects the dynamic and static performance of the servo valve and the dynamic response of the valve control system during use. Therefore, testing the natural frequency of the armature assembly is very important.

[0003] Traditional armature assembly natural frequency testing devices are unidirectional. After fixing the armature assembly, an upward or downward magnetic force is applied to one end of the armature extension rod, causing a change in the armature assembly. The other end is connected to a measuring device such as an oscilloscope. By observing the changes in the applied magnetic force at the test end of the armature assembly, the natural frequency of the armature assembly can be calculated. However, traditional testing devices can only apply upward or downward forces to the armature assembly, resulting in insufficient testing range and an inability to obtain all the characteristics of the armature assembly. Furthermore, since the armature assembly is a high-precision component in servo valve products, traditional testing methods cannot meet the comprehensive testing requirements of the armature assembly. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a device and method for testing the natural frequencies of different modes of the armature assembly in a servo valve. This method can test and verify the natural frequencies of different modes of the armature assembly, a core component of the servo valve, during the research and development stage. It also ensures that the natural frequency range is avoided during assembly, adjustment, and use to prevent abnormal noises and malfunctions caused by approaching or reaching the natural frequency, thereby improving the reliability of the servo valve and valve control system.

[0005] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows:

[0006] A device for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve includes an upper magnetic conductor, pole shoes, a lower magnetic conductor, magnets, and a coil. The armature assembly is mounted on the lower magnetic conductor, which has a through hole in the middle for mounting a spring tube to fix the armature assembly. The two armature ends of the armature assembly extend from the left and right ends above the lower magnetic conductor. Magnets are provided above the front and rear ends of the lower magnetic conductor, and the upper magnetic conductor is provided between the two magnets. The upper magnetic conductor, the lower magnetic conductor, and the magnets form a magnetic path. A coil is provided outside the armature end of the armature assembly within the range of the lower magnetic conductor. A pole shoe is provided outside the portion of the armature end of the armature assembly that extends beyond the coil. The pole shoes are respectively connected to the upper magnetic conductor or the lower magnetic conductor.

[0007] Furthermore, there are four pole shoes, two of which are connected to the upper magnetic conductor and the other two are connected to the lower magnetic conductor; the four pole shoes are respectively located on the front and rear sides of the two armature ends of the armature assembly.

[0008] Furthermore, the pole shoe is a fixed end that is connected to the upper or lower magnetic conductor at one end, and the other end of the pole shoe is a mating end of the armature assembly. The mating end of the pole shoe is provided with an inward concave arc surface that mates with the arc surface of the armature end of the armature assembly. The inward concave arc surface of the pole shoe is close to the arc surface of the armature end of the armature assembly, and there is a gap between the two to accommodate small deformations.

[0009] Furthermore, the pole shoe is detachably connected to the upper and lower magnetic conductors via screws.

[0010] Furthermore, both the upper and lower magnetic conductors are provided with two sets of connection holes for connecting pole shoes at their left and right ends. When the pole shoe is connected to one set of connection holes, it is located at the front end of the armature end of the armature assembly, and when the pole shoe is connected to the other set of connection holes, it is located at the rear end of the armature end of the armature assembly.

[0011] Furthermore, it also includes a side elastic sheet, which is located between the coil and the magnet to prevent the magnet from contacting the coil.

[0012] A method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve is disclosed. Using the aforementioned testing device for the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve, pole shoes are installed on upper and lower magnetic conductors. Two pole shoes on the same side of the upper and lower magnetic conductors are installed diagonally. Two pole shoes on the upper magnetic conductor are installed either on the same side or diagonally, depending on the testing requirements. The armature portion of the armature assembly is placed between the two pole shoes, forming a complete magnetic circuit. Then, the coil is energized, and the armature assembly is deformed based on the magnetic attraction or repulsion between the pole shoes and the armature, and the natural frequency of the armature assembly is measured.

[0013] Furthermore, when the two pole shoes on the upper magnetic conductor are on the same side, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor, by applying a stable current source or voltage source to one coil and acquiring the signal from the other coil, the natural frequency of the armature assembly in the lateral bending mode can be obtained.

[0014] Furthermore, when the two pole shoes on the upper magnetic conductor are on opposite sides, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor, by applying a stable current source or voltage source to one coil and acquiring the signal from the other coil, the natural frequency of the armature assembly in the circumferential rotation mode can be obtained.

[0015] The beneficial effects of this invention are:

[0016] 1. This invention, through the special arc surface design of the pole shoes, can form a magnetic field of equal strength and stability on the side arc surface of the armature, thereby exerting circumferential rotational or lateral bending force on the side of the armature, which makes up for the deficiency of existing tests that can only measure the natural frequency under the axial bending mode. At the same time, by changing the installation position and direction of the pole shoes, the stress state of the armature can be changed, thereby testing the natural frequency of the armature assembly under multiple modes.

[0017] 2. The testing device of the present invention is inexpensive, simple and effective in design, and the testing method is simple and easy to operate. It is low in cost but highly reliable in testing. The test results have guiding significance for the assembly and adjustment of servo valves, working stability and dynamic analysis of valve control systems. At the same time, it can also serve as a reference for the problem of abnormal noise in existing servo valves.

[0018] 3. The present invention has a high degree of versatility, and the armature assembly of all servo valves can be tested by the testing device of the present invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is an isometric view of the servo valve armature assembly natural frequency testing device of the present invention in different modes;

[0021] Figure 2 This is a front view of the servo valve armature assembly natural frequency testing device of the present invention in different modes;

[0022] Figure 3 This is a front view and cross-sectional view of the servo valve armature assembly natural frequency testing device of the present invention.

[0023] The components include: 1-upper conductor magnet, 2-screw, 3-armature assembly, 4-pole shoe, 5-lower conductor magnet, 6-first stage base assembly, 7-magnet, 8-pad, and 9-coil. Detailed Implementation

[0024] This section describes embodiments of the present invention, used to explain and illustrate the technical solutions of the present invention. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating directions or positional relationships, are given in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include more than one of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrated connection; they can refer to a mechanical connection or a point connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] A device for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve includes an upper magnetic conductor 1, a pole shoe 4, a lower magnetic conductor 5, a magnet 7, and a coil 9. The armature assembly 3 is mounted on the lower magnetic conductor 5. The lower magnetic conductor 5 has a through hole in the middle for mounting and fixing a spring tube for the armature assembly 3. The two armature ends of the armature assembly 3 extend from the left and right ends above the lower magnetic conductor 5. Magnets 7 are provided above the front and rear ends of the lower magnetic conductor 5. The upper magnetic conductor 1 is provided between the two magnets 7. The upper magnetic conductor 1, the lower magnetic conductor 5, and the magnet 7 form a magnetic path. A coil 9 is provided outside the armature end of the armature assembly 3 within the range of the lower magnetic conductor 5. A pole shoe 4 is provided outside the part of the armature end of the armature assembly 3 that extends out of the coil 9. The pole shoe 4 is connected to the upper magnetic conductor 1 or the lower magnetic conductor 5 respectively.

[0028] There are four pole shoes 4, two of which are connected to the upper magnetic conductor 1 and the other two are connected to the lower magnetic conductor 5; the four pole shoes 4 are respectively located on the front and rear sides of the two armature ends of the armature assembly 3.

[0029] The pole shoe 4 is a fixed end that is connected to the upper magnetic conductor 1 or the lower magnetic conductor 5 at one end, and the other end of the pole shoe 4 is a mating end of the armature assembly. The mating end of the pole shoe 4 is provided with an inward concave arc surface that mates with the armature end side arc surface of the armature assembly 3. The inward concave arc surface of the pole shoe 4 is close to the armature end side arc surface of the armature assembly 3, and there is a gap between the two to accommodate small deformations.

[0030] The pole shoe 4 is detachably connected to the upper magnet 1 and the lower magnet 5 by screw 2.

[0031] Both ends of the upper magnetic conductor 1 and the lower magnetic conductor 5 are provided with two sets of connection holes for connecting the pole shoes 4. When the pole shoes 4 are connected to one set of connection holes, they are located at the front end of the armature end of the armature assembly 3. When the pole shoes 4 are connected to the other set of connection holes, they are located at the rear end of the armature end of the armature assembly 3.

[0032] It also includes a side elastic sheet, which is located between the coil 9 and the magnet 7 to prevent the magnet 7 from contacting the coil 9.

[0033] A method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve is disclosed. Using the aforementioned testing device for the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve, pole shoes are installed on upper and lower magnetic conductors. Two pole shoes on the same side of the upper and lower magnetic conductors are installed diagonally. Two pole shoes on the upper magnetic conductor are installed either on the same side or diagonally, depending on the testing requirements. The armature portion of the armature assembly is placed between the two pole shoes, forming a complete magnetic circuit. Then, the coil is energized, and the armature assembly is deformed based on the magnetic attraction or repulsion between the pole shoes and the armature, and the natural frequency of the armature assembly is measured.

[0034] Furthermore, when the two pole shoes on the upper magnetic conductor are on the same side, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor, by applying a stable current source or voltage source to one coil and acquiring the signal from the other coil, the natural frequency of the armature assembly in the lateral bending mode can be obtained.

[0035] When the two pole shoes on the upper magnetic conductor are on opposite sides, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor, a stable current source or voltage source is applied to one coil, and the other coil performs signal acquisition, so that the natural frequency of the armature assembly in the circumferential rotation mode can be obtained.

[0036] The following is another embodiment of the present invention.

[0037] like Figure 1As shown, this invention discloses a device and method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve. The testing device includes an upper magnetic conductor 1, screws 2, an armature assembly 3, pole shoes 4, a lower magnetic conductor 5, a primary seat assembly 6, magnets 7, pads 8, coils 9, and side elastic plates. The armature assembly 3 is fixed to the primary seat assembly 6 by screws. Two pads 8 are placed on the primary seat, and the lower magnetic conductor 5 is placed above the pads 8. Coils 9 are placed on the two armature arms of the armature, and side elastic plates are placed on the sides of the coils 9 and pressed and fixed by magnets 7. The upper magnetic conductor 1 is placed above the coils 9. The upper magnetic conductor 1, magnets 9, lower magnetic conductor 5, pads 8, and primary seat assembly 6 are fixed together by long screws. The four pole shoes 4 are installed in pairs on the upper and lower magnetic conductors.

[0038] The pole shoe is designed with one end as an arc surface with the same curvature as the side of the armature. The two side arc surfaces of the armature form two equidistant arc air gaps with the upper and lower pole shoe arc surfaces respectively. The other end of the pole shoe is provided with two threaded holes. The pole shoe and the magnetic conductor are connected and fixed by screws.

[0039] Four threaded holes are provided on both sides of the upper and lower magnetic conductors. The position of the pole shoe can be changed by using different threaded mounting holes according to the test requirements, and air gap magnetic circuits in different directions can be built to change the force on the armature.

[0040] The test method described above involves applying a stable current or voltage source to one coil and acquiring a signal from the other coil when the two pole shoes on the upper magnet are on the same side and the two pole shoes on the lower magnet are diagonally opposite to the two pole shoes on the upper magnet. This yields the natural frequency of the armature assembly in the lateral bending mode. Alternatively, when the two pole shoes on the upper magnet are on opposite sides and the two pole shoes on the lower magnet are diagonally opposite to the two pole shoes on the upper magnet, applying a stable current or voltage source to one coil and acquiring a signal from the other coil yields the natural frequency of the armature assembly in the circumferential rotation mode.

[0041] To better illustrate the present invention, a detailed description is provided below in conjunction with the accompanying drawings.

[0042] The present invention will be further described in detail below through specific embodiments. Please also refer to... Figures 1-3 .

[0043] A device and method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve. The testing device includes an upper magnetic conductor 1, a screw 2, an armature assembly 3, a pole shoe 4, a lower magnetic conductor 5, a primary seat assembly 6, a magnet 7, a pad 8, a coil 9, and a side elastic sheet. Wherein:

[0044] The pole shoe is designed with one end as an arc surface with the same curvature as the side of the armature. The two side arc surfaces of the armature form two equidistant arc air gaps with the upper and lower pole shoe arc surfaces respectively. The other end of the pole shoe is provided with two threaded holes. The pole shoe and the magnetic conductor are connected and fixed by screws.

[0045] Four threaded holes are provided on both sides of the upper and lower magnetic conductors. The position of the pole shoe can be changed by using different threaded mounting holes according to the test requirements, and air gap magnetic circuits in different directions can be built to change the force on the armature.

[0046] according to Figure 1 and Figure 3 As shown, install and secure each component.

[0047] Before testing the natural frequency of the armature assembly in the circumferential rotation mode, the two pole shoes on the upper magnetic conductor are installed on opposite sides, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor. During the test, a stable current source or voltage source is applied to one coil, and the other coil collects the signal to obtain the natural frequency of the armature assembly in the circumferential rotation mode.

[0048] Before testing the natural frequency of the armature assembly under lateral bending mode, the two pole shoes on the upper magnetic conductor are installed on the same side, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor. A stable current source or voltage source is applied to one coil, and the other coil collects the signal. The natural frequency of the armature assembly under lateral bending mode can be obtained.

[0049] Compared with existing methods for measuring the natural frequency of armatures, this invention has the following advantages:

[0050] (1) To overcome the limitation of existing armature assemblies that can only detect the natural frequencies of axial modes, a device and method for detecting the natural frequencies of axial rotation and lateral bending modes are proposed, filling the gap in this testing method.

[0051] (2) The testing device is simple in design and easy to manufacture, and the testing method is simple and accurate;

[0052] (3) A testing device that can test the natural frequencies of multiple modes simply by changing the installation position of the pole shoes, which is highly efficient;

[0053] (4) The unique arc surface design of the pole shoes ensures that the two side arc surfaces of the armature form two equidistant arc air gaps with the upper and lower pole shoe arc surfaces respectively, which can form an equal and stable magnetic field on the side arc surfaces of the armature. During the test, the armature is subjected to uniform force and the test accuracy is high.

Claims

1. A device for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve, characterized in that, It includes an upper magnetic conductor (1), a pole shoe (4), a lower magnetic conductor (5), a magnet (7), and a coil; the armature assembly (3) is mounted on the lower magnetic conductor (5), the lower magnetic conductor (5) has a through hole in the middle for mounting and fixing the spring tube of the armature assembly (3), the two armature ends of the armature assembly (3) extend from the left and right ends above the lower magnetic conductor (5), the lower magnetic conductor (5) is provided with magnets (7) above the front and rear ends, the upper magnetic conductor (1) is provided between the two magnets (7), the upper magnetic conductor (1), the lower magnetic conductor (5) and the magnet (7) form a magnetic path; the armature end of the armature assembly (3) is provided with a coil outside the lower magnetic conductor (5), the part of the armature end of the armature assembly (3) extending out of the coil is provided with a pole shoe (4), the pole shoe (4) is connected to the upper magnetic conductor (1) or the lower magnetic conductor (5) respectively; There are four pole shoes (4), two of which are connected to the upper magnetic conductor (1) and the other two are connected to the lower magnetic conductor (5); the four pole shoes (4) are respectively located on the front and rear sides of the two armature ends of the armature assembly (3); One end of the pole shoe (4) is a fixed end connected to the upper magnetic conductor (1) or the lower magnetic conductor (5), and the other end of the pole shoe (4) is a mating end of the armature assembly. The mating end of the pole shoe (4) is provided with an inward concave arc surface that mates with the armature end side arc surface of the armature assembly (3). The inward concave arc surface of the pole shoe (4) is close to the armature end side arc surface of the armature assembly (3), and there is a gap between the two to accommodate small deformations. The upper magnet (1) and the lower magnet (4) are installed diagonally on the same side. The two pole shoes (4) on the upper magnet (1) are installed on the same side or diagonally according to the test requirements. The armature part of the armature assembly (3) is placed between the two pole shoes (4) to form a complete magnetic circuit.

2. The device for testing the natural frequencies of different modes of an electro-hydraulic servo valve armature assembly according to claim 1, characterized in that, The pole shoe (4) is detachably connected to the upper magnet (1) and the lower magnet (5) by screws (2).

3. The device for testing the natural frequencies of different modes of an electro-hydraulic servo valve armature assembly according to claim 2, characterized in that, The upper magnetic conductor (1) and the lower magnetic conductor (5) are provided with two sets of connection holes for connecting pole shoes (4) at their left and right ends. When the pole shoe (4) is connected to one set of connection holes, it is located at the front end of the armature end of the armature assembly (3). When the pole shoe (4) is connected to the other set of connection holes, it is located at the rear end of the armature end of the armature assembly (3).

4. The device for testing the natural frequencies of different modes of an electro-hydraulic servo valve armature assembly according to claim 1, characterized in that, It also includes a side elastic sheet, which is located between the coil and the magnet (7) to prevent the magnet (7) from contacting the coil.

5. A method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve, using a testing device for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve as described in any one of claims 1-4, characterized in that, The pole shoes are installed on the upper and lower magnetic conductors respectively; then the coil is energized, and the armature assembly is deformed according to the magnetic attraction or repulsion between the pole shoes and the armature, and the natural frequency of the armature assembly is measured.

6. The method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve according to claim 5, characterized in that, When the two pole shoes on the upper magnetic conductor are on the same side, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor, a stable current source or voltage source is applied to one coil, and the other coil performs signal acquisition, so that the natural frequency of the armature assembly in the lateral bending mode can be obtained.

7. The method for testing the natural frequencies of different modes of an armature assembly in an electro-hydraulic servo valve according to claim 5, characterized in that, When the two pole shoes on the upper magnetic conductor are on opposite sides, and the two pole shoes on the lower magnetic conductor are installed diagonally opposite to the two pole shoes on the upper magnetic conductor, a stable current source or voltage source is applied to one coil, and the other coil performs signal acquisition, so that the natural frequency of the armature assembly in the circumferential rotation mode can be obtained.

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