A high-frequency and high-acceleration electric vibration test bench

Abstract

The present invention discloses a high-frequency, high-acceleration electric vibration test bench. The magnetic field direction of the permanent magnet of the electric vibration test bench is arranged vertically. By arranging an upper magnetic ring (or a middle magnetic ring) to correspond to a central magnetic pole, a magnetic field air gap is formed between the upper magnetic ring (or the middle magnetic ring) and the central magnetic pole. Due to structural limitations of the bench body, the cross-sectional area S1 of the magnetic field air gap remains unchanged. However, the cross-sectional area Am of the permanent magnet can be increased by extending the length of the permanent magnet in the radial direction. According to the air gap magnetic induction intensity B=Br*Am / S1, the air gap magnetic induction intensity B can be effectively increased while maintaining the structure of the dynamic coil assembly of the vibration table. This can further improve the electromagnetic thrust of the vibration table, thereby meeting the test requirements of the vibration table for high frequency and high acceleration.

Description

Technical Field

[0001] The invention relates to the technical field of vibration test benches, in particular to a high-frequency and high-acceleration electric vibration test bench. Background Art

[0002] The rapid development of my country's aero-engine technology has led to higher requirements for turbine blade reliability testing, with the need for fatigue life assessment of turbine / compressor engine blades being particularly urgent. Turbine blades, due to their small size, high natural frequency (some test frequencies ≥15kHz), and the need to achieve excitation accelerations exceeding 150g, present a dual challenge to the test system: on the one hand, the upper limit of the test frequency must be increased, and on the other hand, high acceleration output capability must be maintained. The dynamic coil assembly, as the power drive component of the vibration table, has a significant impact on the table's natural frequency. Based on experience in vibration test table design, the system's upper test frequency limit is approximately 1.3 times the first-order axial natural frequency of the dynamic coil. This means that to achieve the 15kHz test requirement, the first-order axial natural frequency of the dynamic coil must be at least 11.5kHz.

[0003] To ensure the natural frequency of the dynamic coil assembly meets test requirements, the dynamic coil assembly needs to be optimized. This requires reducing its structural dimensions, including the table diameter and the height of the dynamic coil frame. This reduces the effective length of the dynamic coil drive coil. According to the electromagnetic force formula F=B*L*I (B is the air gap magnetic induction intensity, L is the effective length of the drive coil, and I is the current), shortening the effective length of the drive coil reduces the electromagnetic force, making it difficult to meet the thrust required for high acceleration. Therefore, it is difficult to simultaneously meet the design requirements of high frequency and high acceleration during the vibration table design process.

[0004] According to the electromagnetic force formula F=B*L*I, the thrust loss caused by the reduction of the moving coil length can be compensated in the following two ways:

[0005] 1. Increasing the drive current will cause the coil to generate heat exponentially, significantly increasing the heat generated by the device. This will require a strengthened cooling system for the vibration table, complicating the structure and affecting its natural frequency. Furthermore, as the size of the dynamic components decreases, the heat dissipation space becomes smaller, making it difficult to fully ensure heat dissipation. The thermal effects of the device will adversely affect its performance.

[0006] 2. Enhance the magnetic field air gap magnetic induction intensity B. The value of the air gap magnetic induction intensity B is determined by the ratio of the total magnetic flux Φ of the magnetic circuit to the air gap cross-sectional area S1 (B=Φ / S1). The total magnetic flux Φ of the system is equal to the product of the permanent magnet residual magnetic flux density Br and the permanent magnet magnetic field cross-sectional area Am (Φ=Br*Am), that is, the air gap magnetic induction intensity B= Br*Am / S1. Figure 1As shown, the current closed-loop magnetic circuit design of the electric vibration table includes an excitation component 1 and a moving coil component 2. The permanent magnet 10 of the excitation component 1 and the moving coil component 2 are concentrically nested. The magnetic field cross section of the permanent magnet 10 is parallel to the cross section of the magnetic field air gap 3 ( Figure 1 The arrow in the middle indicates the direction of the magnetic lines of force. The magnetic field cross-section of the permanent magnet and the cross-section of the magnetic field air gap 3 are both perpendicular to the direction of the magnetic field lines. The ratio (Am / S1) of the magnetic field cross-sectional area Am of the permanent magnet 10 to the magnetic field air gap cross-sectional area S1 is relatively fixed. The magnetic field air gap cross-sectional area S1 is determined by the size of the moving coil assembly. In this case, the air gap magnetic induction intensity B can only be enhanced by increasing the permanent magnet residual magnetic flux density Br. However, due to material limitations, it is difficult to significantly increase the permanent magnet residual magnetic flux density Br, and therefore it is difficult to meet the high-frequency and high-acceleration thrust requirements of the vibration table.

[0007] Therefore, it is necessary to further improve the structure of the existing electric vibration test bench to meet the requirements of high-frequency and high-acceleration tests. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an electric vibration test bench capable of achieving high frequency and high acceleration in view of the deficiencies in the prior art.

[0009] A high-frequency, high-acceleration electric vibration test bench comprises an excitation assembly and a moving coil assembly, wherein the moving coil assembly comprises a moving coil frame and a driving coil arranged on the moving coil frame, the excitation assembly comprises a central magnetic pole, an upper magnetic ring, and a lower yoke, wherein the central magnetic pole is arranged on the lower yoke, the central magnetic pole and the upper magnetic ring are arranged concentrically, a plurality of block permanent magnets distributed in a circular shape are arranged between the upper magnetic ring and the lower yoke, a magnetic field air gap is formed between the upper magnetic ring and the central magnetic pole, the driving coil can be arranged in the magnetic field air gap and can move back and forth along the axis direction of the central magnetic pole, the magnetic field direction of the block permanent magnet is arranged parallel to the axis direction of the central magnetic pole, and the magnetic field strength of the magnetic field air gap is proportional to the radial length direction of the block permanent magnet.

[0010] Preferably, a high-frequency and high-acceleration electric vibration test bench comprises an excitation assembly and a moving coil assembly, the moving coil assembly comprises a moving coil frame and a driving coil arranged on the moving coil frame, the excitation assembly comprises a central magnetic pole, an upper magnetic ring, a middle magnetic ring, and a lower yoke, the central magnetic pole is arranged on the lower yoke, the central magnetic pole, the upper magnetic ring, and the middle magnetic ring are concentrically arranged, a plurality of block permanent magnets distributed in a circular shape are arranged between the upper magnetic ring and the middle magnetic ring and between the middle magnetic ring and the lower yoke, a magnetic field air gap is formed between the middle magnetic ring and the central magnetic pole, the driving coil can be arranged in the magnetic field air gap and move back and forth along the axis direction of the central magnetic pole, the magnetic field direction of the block permanent magnet is arranged parallel to the axis direction of the central magnetic pole, the magnetic field direction of the block permanent magnet between the upper magnetic ring and the middle magnetic ring is opposite to the magnetic field direction of the block permanent magnet between the middle magnetic ring and the lower yoke, and the magnetic field strength of the magnetic field air gap is proportional to the radial length direction of the block permanent magnet.

[0011] Preferably, the block permanent magnet is arranged in a retaining frame, the retaining frame is provided with a plurality of permanent magnet slots distributed in a circumferential shape, the block permanent magnets correspond to the permanent magnet slots one by one, and the retaining frame is concentrically arranged with the central magnetic pole.

[0012] Preferably, the upper magnetic ring is provided with a plurality of upper guide assemblies evenly distributed in a circular shape, the upper guide assemblies are connected to the upper end portion of the moving coil assembly, and the moving coil assembly is suspended so as to be movable up and down through the upper guide assemblies.

[0013] Preferably, the upper guide assembly includes a spring seat and a vibration isolation rubber. The spring seat is fixed on the upper magnetic ring. The spring seat is connected to the vibration isolation rubber. The vibration isolation rubber is connected to the upper end of the moving coil assembly.

[0014] Preferably, the dynamic coil frame includes a central connecting column, a through hole is provided in the center of the central magnetic pole, a lower guide assembly is provided in the through hole, and the central connecting column is connected to the lower guide assembly.

[0015] Preferably, the lower guide assembly includes a guide shaft and a linear bearing, the linear bearing is fixed in the through hole of the center magnetic pole, the guide shaft is cooperatively connected to the linear bearing, and the guide shaft is fixedly connected to the center connecting column.

[0016] Preferably, a central air chamber assembly is further provided below the central magnetic pole, and the guide shaft is connected to the central air chamber assembly.

[0017] Preferably, the dynamic coil frame includes a table top, and the table top is connected to the driving coil through a plurality of radially distributed ribs.

[0018] Preferably, it further includes a magnetic isolation ring, and the magnetic isolation ring corresponds to the position of the block permanent magnet.

[0019] The above technical solution has the following beneficial effects: the magnetic field direction of the permanent magnet of the electric vibration test bench is arranged in an upper and lower direction. By arranging the upper magnetic ring (or middle magnetic ring) to correspond to the central magnetic pole, a magnetic field air gap is formed between the upper magnetic ring (or middle magnetic ring) and the central magnetic pole. In this way, while the air gap cross-sectional area S1 remains unchanged, the permanent magnet cross-sectional area Am can be increased by extending the length of the permanent magnet in the radial direction. According to the air gap magnetic induction intensity B = Br*Am / S1, the air gap magnetic induction intensity B can be greatly improved, thereby increasing the electromagnetic thrust of the vibration table and meeting the high-frequency and high-acceleration test requirements of the vibration table.

[0020] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and illustration and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of the excitation component of the existing electric vibration test bench.

[0022] Figure 2 Schematic diagram of the structure of the excitation assembly of the first embodiment of the present invention.

[0023] Figure 3 Schematic diagram of the magnetic field cross section of the block permanent magnet according to the first embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the structure of the excitation assembly according to the second embodiment of the present invention.

[0025] Figure 5 Schematic diagram of the structure of the retaining frame according to an embodiment of the present invention.

[0026] Figure 6 Schematic diagram of the structure of a vibration test bench according to the third embodiment of the present invention.

[0027] Figure 7 Schematic diagram of the structure of the guide assembly in an embodiment of the present invention.

[0028] Figure 8 Schematic diagram of the structure of the guide assembly according to an embodiment of the present invention.

[0029] Figure 9 Schematic diagram of the structure of the dynamic coil bobbin according to embodiment 3 of the present invention.

[0030] Figure 10 for Figure 9 Bottom view of .

[0031] Explanation of original component numbers: 1. Excitation assembly; 10. Permanent magnet; 11. Block permanent magnet; 12. Center magnetic pole; 13. Upper magnetic ring; 14. Lower yoke; 15 Middle magnetic ring; 2. Moving coil assembly; 21. Moving coil frame; 22. Driving coil; 23. Center connecting column; 24. Moving coil table; 25. Rib plate; 26. Skirt plate; 3. Magnetic field air gap; 4. Upper guide assembly; 41. Spring seat; 42. Vibration isolation rubber; 43. Connecting bolt; 5. Lower guide assembly; 51. Guide shaft; 52. Linear bearing; 53. Connecting bolt; 6. Central air chamber assembly; 61. Air chamber connector; 7. Magnetic isolation ring; 8. Base; 9. Retaining frame; 91 Permanent magnet slot. DETAILED DESCRIPTION

[0032] The following is an explanation of the disclosed embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted in actual size. It is stated in advance. The following embodiments will further explain the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0033] It should be understood that although terms such as "first" and "second" may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. In addition, the term "or" as used herein may include any one or more combinations of the associated listed items, depending on the actual situation.

[0034] Example 1:

[0035] like Figure 2 As shown, the high-frequency and high-acceleration electric vibration test bench provided in this embodiment includes an excitation component 1 and a dynamic coil component 2. The dynamic coil component 2 includes a dynamic coil frame 21 and a drive coil 22 wound on the lower end of the dynamic coil frame 21. The excitation component includes a central magnetic pole 12, an upper magnetic ring 13, and a lower yoke 14. The central magnetic pole 13 is arranged on the lower yoke 14. The central magnetic pole 12 and the upper magnetic ring 13 are arranged concentrically. On the lower yoke 14, the central magnetic pole 12 and the upper magnetic ring 13 are made of magnetic conductive material. A plurality of block permanent magnets 11 are provided between the upper magnetic ring 13 and the lower yoke 14. The plurality of block permanent magnets 11 are evenly distributed in a circular shape along the center of the central magnetic pole 12. The magnetic field direction of the block permanent magnet 11 is arranged parallel to the axial direction of the central magnetic pole 12, as shown in FIG. Figure 2As shown in the direction of the middle arrow, in this embodiment, the magnetic poles S and N of the block permanent magnet 11 are arranged up and down, and the magnetic field of the block permanent magnet 11 passes through the upper magnetic ring 13, the center magnetic pole 12, and the lower yoke 14 in sequence to form a closed magnetic circuit, forming a magnetic field air gap 3 between the upper magnetic ring 13 and the center magnetic pole 12. The driving coil 22 of the moving coil assembly 2 is located in the magnetic field air gap and can move back and forth along the axis of the center magnetic pole.

[0036] According to the formula, the air gap magnetic induction intensity B = Br*Am / S1, in this embodiment, the magnetic field air gap 3 is formed between the upper magnetic ring 13 and the center magnetic pole 12. The magnetic field cross-sectional area of ​​the upper magnetic ring 13 remains unchanged, and the magnetic field air gap cross-sectional area S1 also remains unchanged. The magnetic field air gap 3 is set in the vertical direction. The magnetic field cross-sectional area of ​​the block permanent magnet 11 is set in the horizontal direction, perpendicular to the magnetic field air gap cross-sectional area. Figure 3 As shown, the magnetic field cross-sectional area of ​​the block permanent magnet 11 is the product L1*W of the length L1 and width W of the block permanent magnet. Due to the limitation of the size of the moving coil, the width W of the block permanent magnet remains unchanged, but it can be extended to L1+L2 in the length direction of the block permanent magnet. In this way, the magnetic field cross-sectional area Am of the block permanent magnet can be increased to (L1+L2)*W. In other words, the magnetic field strength of the magnetic field air gap is proportional to the radial length of the block permanent magnet. In this way, by increasing the radial length of the permanent magnet, the magnetic induction intensity B of the air gap can be increased, thereby increasing the thrust of the vibration table and meeting the high acceleration test requirements of the vibration table.

[0037] In this embodiment, the magnetic field of the block permanent magnet 11 is arranged vertically, so its magnetic field cross section is arranged horizontally, so that it can be arranged in the radial direction perpendicular to the axis of the central magnetic pole ( Figure 2 Increasing the length of the block permanent magnet 11 (in the direction indicated by the arrow d) increases the magnetic field cross-sectional area Am, thereby increasing the air gap magnetic induction intensity B. Since this approach only requires increasing the length of the block permanent magnet 11 horizontally, without changing its width, it does not affect the dimensions of the moving coil assembly itself and, consequently, its first-order axial natural frequency. The block permanent magnet 11 has a rectangular cross-section, resulting in a simple and reliable magnetic circuit structure and easy processing, effectively ensuring machining and assembly precision.

[0038] As a preferred embodiment of the present invention, the center magnetic pole 12 and the lower yoke 14 can be set as an integral structure, and the lower yoke 14 adopts a circular structure and is set concentrically with the center magnetic pole 12. This method can reduce leakage magnetic flux and further increase the air gap magnetic induction intensity B.

[0039] Example 2:

[0040] like Figure 4As shown, the high-frequency, high-acceleration electric vibration test bench provided in this embodiment includes an excitation assembly 1 and a moving coil assembly 2. The excitation assembly includes a center magnetic pole 12, an upper magnetic ring 13, a middle magnetic ring 15, and a lower yoke 14. The center magnetic pole 12 is disposed on the lower yoke 14. The center magnetic pole 12, the upper magnetic ring 13, and the middle magnetic ring 15 are concentrically arranged. On the lower yoke 14, the center magnetic pole 12, the upper magnetic ring 13, and the middle magnetic ring 15 are made of magnetically conductive material. A plurality of block permanent magnets 11 are arranged in a circular pattern between the upper magnetic ring 13 and the middle magnetic ring 15. The plurality of block permanent magnets 11 are evenly distributed in a circular pattern around the center of the center magnetic pole 12. A plurality of block permanent magnets 11 are also arranged in a circular pattern between the middle magnetic ring 15 and the lower yoke 14. The plurality of block permanent magnets 11 are evenly distributed in a circular pattern around the center of the center magnetic pole 12. The magnetic field direction of the block permanent magnets 11 is arranged parallel to the axial direction of the center magnetic pole 12. A magnetic field air gap 3 is formed between the middle magnetic ring 15 and the central magnetic pole 12 , and the driving coil 22 is arranged in the magnetic field air gap 3 so as to be movable back and forth along the axis of the central magnetic pole.

[0041] In this embodiment, two layers of block permanent magnets are provided. The magnetic field direction of the block permanent magnets between the upper magnetic ring 13 and the middle magnetic ring 15 is opposite to the magnetic field direction of the block permanent magnets between the middle magnetic ring 15 and the lower yoke 14. Figure 4 As shown in , the S pole of the block permanent magnet located between the upper magnetic ring 13 and the middle magnetic ring 15 is opposite to the S pole of the block permanent magnet located between the middle magnetic ring 15 and the lower yoke 14. This structure not only increases the air gap magnetic flux density B by increasing the length of the upper and lower layers of block permanent magnets 11, but also, because the magnetic fields of the upper and lower layers of permanent magnets in the middle magnetic ring 15 are superimposed, the air gap magnetic flux density B is multiplied, which can provide the vibration table with greater electromagnetic thrust. This structure eliminates the need to increase the effective length of the drive coil 22, allowing the drive coil to have a higher natural frequency, thereby better meeting the high-frequency and high-acceleration test requirements of the vibration table.

[0042] As a preferred embodiment of this embodiment, a retainer 9 (such as Figure 5 As shown in the figure, the retaining frame 9 has a circular structure and is provided with a plurality of permanent magnet slots 91 distributed in a circumferential shape. The positions of the permanent magnet slots 91 correspond one-to-one to the positions of the block permanent magnets 11. The block permanent magnets 11 are arranged in the permanent magnet slots 91. This method facilitates the fixed installation of the permanent magnets and solves the problem of difficult assembly caused by the strong interaction force between the block permanent magnets.

[0043] Example 3:

[0044] like Figure 6As shown, the high-frequency and high-acceleration electric vibration test bench provided in this embodiment adopts the excitation assembly and the moving coil assembly shown in Example 2. The vibration test bench is also provided with a plurality of upper guide assemblies 4 on the upper magnetic ring 13. The plurality of upper guide assemblies 4 are evenly distributed along the circumferential direction of the upper magnetic ring 13. The upper guide assembly 4 is connected to the upper end of the moving coil assembly 2. The upper guide assembly 4 is used to support and guide the moving coil assembly 2. The moving coil assembly 2 can be suspended in the magnetic field air gap 3 by the upper guide assembly 4 so that the magnetic induction coil 22 of the moving coil assembly 2 is relative to the magnetic field air gap 3.

[0045] like Figure 7 As shown, the upper guide assembly 4 includes a spring seat 41 and a vibration-isolating rubber 42. The spring seat 41 is fixed to the upper magnetic ring 13. The spring seat 41 and the vibration-isolating rubber 42 are connected by a connecting bolt 43. One end of the connecting bolt 43 passes through the spring seat 4 and the vibration-isolating rubber 42 and is connected to the upper end of the moving coil assembly 2. With this structure, the multiple upper guide assemblies 4 can limit the moving coil assembly 2 in the radial direction, ensuring that the moving coil assembly 2 is concentric with the excitation assembly, limiting the moving coil assembly, and providing support for the moving coil assembly 2.

[0046] In order to play a better guiding role, a through hole is provided in the center of the center magnetic pole 12, and a lower guide component 5 is provided in the through hole. A central connecting column 23 is provided in the center of the moving coil frame 21, and the lower end of the central connecting column 23 is inserted into the through hole and connected to the lower guide component 5. Figure 8 As shown, the lower guide assembly 5 comprises a guide shaft 51 and a linear bearing 52. The linear bearing 52 is fixed in the through hole of the center magnetic pole 12. The guide shaft 51 and the linear bearing 52 are cooperatively connected. The guide shaft 51 can slide up and down along the linear bearing 52. The guide shaft 51 is fixedly connected to the center connecting column 23 via a connecting bolt 53. The lower guide assembly 5 serves as a guide when the moving coil assembly vibrates up and down.

[0047] To meet high-frequency requirements, the dynamic coil assembly of this electrodynamic vibration test bench is designed with relatively small dimensions. In this embodiment, two sets of upper and lower guide assemblies are provided. This bidirectional guidance structure enhances the vibration table's anti-overturning performance and ensures stable operation under complex operating conditions. For example, the blades are secured to the dynamic coil assembly's tabletop using a cantilever mounting structure. When the system enters resonant fatigue testing, the violent swinging torque generated by the blades is effectively balanced by the coordinated restraint of the upper and lower guide assemblies, thereby enhancing the overall dynamic stability of the vibration test system.

[0048] like Figure 5As shown, as a preferred embodiment, the through hole of the center pole 12 passes through the lower yoke 14, and a central air chamber assembly 6 is further provided under the lower yoke 14. The central air chamber assembly 6 is arranged on the base 8, and the guide shaft 51 of the lower guide assembly 5 is connected to the central air chamber assembly 6 through a connecting piece 61. The central air chamber assembly 6 can support the guide shaft 51 and the dynamic coil assembly 2 connected to the guide shaft 51, which can further balance the mass of the moving parts of the vibration table, offset the gravity of the dynamic coil assembly of the vibration table and the test product, ensure that the dynamic coil assembly is in the center position, and ensure that the first-order frequency of the dynamic coil assembly meets the high-frequency test requirements.

[0049] As another preferred embodiment of the present invention, the vibration test bench also includes a magnetic isolation ring 7, which corresponds to the position of the block permanent magnet 11. The magnetic isolation ring 7 is arranged on the outside of the block permanent magnet 11. The magnetic isolation ring 7 is made of aluminum material to reduce leakage magnetic flux, thereby further increasing the magnetic field strength of the magnetic field air gap 3.

[0050] like Figure 9 、 10 As shown in the figure, as a specific embodiment, the dynamic coil frame of the dynamic coil assembly 2 in this embodiment includes a dynamic coil table 24 and a skirt 26. A central connecting column 23 is provided at the center of the dynamic coil table 24. A plurality of radially distributed ribs 25 are provided on the central connecting column 23. The inner side of the rib 25 is connected to the central connecting column 23, and the upper and lower ends of the outer side of the rib 25 are connected to the dynamic coil table 24 and the skirt 26 respectively. In order to increase the first-order natural frequency of the system, a dynamic coil table 24 with a smaller diameter is usually used. The dynamic coil table 24 is connected to the drive coil using radial ribs. By increasing the thickness of the ribs and reducing the radial dimensions, the axial stiffness can be increased, thereby improving the load transfer of the driving force of the dynamic coil assembly, thereby better meeting the experimental requirements of high frequency and high acceleration.

[0051] In order to reduce magnetic leakage, without affecting the up and down movement of the dynamic coil assembly 2, a magnetic wedge can be set in the space formed by the upper magnetic ring 13, the center magnetic pole 12 and the adjacent ribs. The magnetic wedge can reduce the gap between the upper magnetic ring 13 and the center magnetic pole 12, thereby reducing magnetic leakage. This can further increase the air gap magnetic induction intensity in the magnetic field air gap 3, thereby increasing the electromagnetic thrust of the vibration test bench.

[0052] The magnetic field direction of the permanent magnet of this electric vibration test bench is set up and down. By arranging the middle magnetic ring and the center magnetic pole in correspondence, a magnetic field air gap is formed between the middle magnetic ring and the center magnetic pole. Due to the structural limitations of the vibration table, the cross-sectional area S1 of the magnetic field air gap remains unchanged. However, the cross-sectional area Am of the permanent magnet can be increased by extending the length of the permanent magnet in the radial direction. According to the air gap magnetic induction intensity B = Br*Am / S1, this can also effectively increase the air gap magnetic induction intensity B, thereby improving the electromagnetic thrust of the vibration table and meeting the high-frequency and high-acceleration test requirements of the vibration table.

[0053] The contents disclosed above are only preferred feasible embodiments of the present invention and do not limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the description and drawings of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A high-frequency, high-acceleration electric vibration test bench, comprising an excitation assembly and a moving coil assembly, wherein the moving coil assembly comprises a moving coil frame and a drive coil disposed on the moving coil frame, characterized in that: The excitation assembly includes a central magnetic pole, an upper magnetic ring, a middle magnetic ring, and a lower yoke. The central magnetic pole is arranged on the lower yoke. The central magnetic pole, the upper magnetic ring, and the middle magnetic ring are concentrically arranged. A plurality of block permanent magnets distributed in a circular shape are provided between the upper magnetic ring and the middle magnetic ring and between the middle magnetic ring and the lower yoke. A magnetic field air gap is formed between the middle magnetic ring and the central magnetic pole. The driving coil can be arranged in the magnetic field air gap and can move back and forth along the axis direction of the central magnetic pole. The magnetic field direction of the block permanent magnet is arranged parallel to the axis direction of the central magnetic pole. The magnetic field direction of the block permanent magnet between the upper magnetic ring and the middle magnetic ring is opposite to the magnetic field direction of the block permanent magnet between the middle magnetic ring and the lower yoke. The magnetic field strength of the magnetic field air gap is proportional to the radial length direction of the block permanent magnet.

2. The high-frequency and high-acceleration electric vibration test bench according to claim 1, characterized in that: The block permanent magnet is arranged in a retaining frame, and the retaining frame is provided with a plurality of permanent magnet slots distributed in a circumferential shape. The block permanent magnets correspond to the permanent magnet slots one by one, and the retaining frame is concentrically arranged with the central magnetic pole.

3. The high-frequency and high-acceleration electric vibration test bench according to claim 1, characterized in that: The upper magnetic ring is provided with a plurality of upper guide assemblies evenly distributed in a circumferential shape, the upper guide assemblies are connected to the upper end of the moving coil assembly, and the moving coil assembly is suspended so as to be movable up and down through the upper guide assemblies.

4. The high-frequency and high-acceleration electric vibration test bench according to claim 3, characterized in that: The upper guide assembly includes a spring seat and a vibration isolation rubber. The spring seat is fixed on the upper magnetic ring. The spring seat is connected to the vibration isolation rubber. The vibration isolation rubber is connected to the upper end of the moving coil assembly.

5. The high-frequency and high-acceleration electric vibration test bench according to claim 3, characterized in that: The dynamic coil frame includes a central connecting column. A through hole is provided in the center of the central magnetic pole. A lower guide component is provided in the through hole. The central connecting column is connected to the lower guide component.

6. The high-frequency and high-acceleration electric vibration test bench according to claim 5, characterized in that: The lower guide assembly includes a guide shaft and a linear bearing. The linear bearing is fixed in the through hole of the central magnetic pole. The guide shaft is cooperatively connected with the linear bearing, and the guide shaft is fixedly connected with the central connecting column.

7. The high-frequency and high-acceleration electric vibration test bench according to claim 6, characterized in that: A central air chamber component is also provided below the central magnetic pole, and the guide shaft is connected to the central air chamber component.

8. The high-frequency and high-acceleration electric vibration test bench according to claim 1, characterized in that: The dynamic coil frame includes a table top, and the table top is connected to the driving coil through a plurality of radially distributed ribs.

9. The high-frequency and high-acceleration electric vibration test bench according to claim 1, characterized in that: It also includes a magnetic isolation ring, and the magnetic isolation ring corresponds to the position of the block permanent magnet.

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