Magnetic suspension voice coil motor

Abstract

The utility model belongs to the technical field of semiconductor equipment, and provides a magnetic suspension voice coil motor which comprises a first assembly and a second assembly which are spaced from each other, the axial direction of the first assembly is the z direction, the first assembly comprises an inner ring magnet and an outer ring magnet which are coaxially arranged, and the outer ring magnet sleeves the outer side of the inner ring magnet; the second assembly comprises a first coil, a middle back iron and a second coil which are sequentially and coaxially arranged in the z direction and annularly arranged between the inner ring magnet and the outer ring magnet, and the magnetizing directions of the inner ring magnet and the outer ring magnet are both in the radial direction of the inner ring magnet and the outer ring magnet. Magnetic levitation force and Lorentz force are generated between the first assembly and the second assembly, the gravity of the vertical micropositioner and the reverse acting force of the reed can be compensated through the magnetic levitation force, and the vertical micropositioner can be driven through the Lorentz force. The vertical resultant force of the magnetic levitation force and the Lorentz force is linearly changed in the displacement range of the vertical micropositioner, so that the magnetic levitation voice coil motor has the characteristic of constant rigidity, and the problem of heating of the motor is solved.

Description

Technical Field

[0001] This application relates to the field of semiconductor equipment technology, and in particular to a magnetic levitation voice coil motor. Background Technology

[0002] In the field of semiconductor manufacturing and inspection, the workpiece stage not only needs to facilitate device transfer with the semiconductor transport system but also needs to achieve precise positioning of the supported semiconductor devices. The workpiece stage is equipped with a vertical micro-stage responsible for achieving precise positioning of semiconductor devices (such as silicon wafers) along three axes: vertical, x-axis, and y-axis. However, with technological advancements, higher requirements have been placed on the motion precision control of the vertical micro-stage.

[0003] Vertical micro-motion stages typically employ a three-point or four-point actuator layout. To ensure vertical output performance, reeds are used as guiding elements for vertical motion and decoupling elements for pitch and yaw. To improve the control accuracy of vertical micro-motion stages, the actuator not only needs to provide vertical driving force for the motion process but also needs to compensate for the gravity of the vertical micro-motion stage and the reaction force of the reeds.

[0004] Currently, the vertical motion of a vertical micro-motion stage typically employs a combination of a gravity compensation device and a voice coil motor to improve its control accuracy. The gravity compensation device uses principles such as air levitation or magnetic levitation to compensate for the gravity of the vertical drive load of the micro-motion stage with constant gravity compensation. The voice coil motor, as the vertical actuator, provides the reaction force of the reed and the driving force for the vertical motion of the micro-motion stage. However, in practical applications, the spring force of the reed is linearly related to the vertical displacement. Within different vertical stroke ranges, especially when the stroke range is large, the varying reaction force of the reed affects the output force of the voice coil motor, leading to increased heat generation and consequently, poor control accuracy of the vertical micro-motion stage equipped with a voice coil motor. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a magnetic levitation voice coil motor to solve the problem that the increased heat generation of the voice coil motor in the prior art leads to poor control accuracy of the vertical micro-motion stage equipped with the voice coil motor.

[0006] To achieve the above and other related objectives, this application provides a magnetic levitation voice coil motor, including a first component and a second component spaced apart from each other, with the axial direction of the first component as the z-direction, and the first component and the second component being able to move relative to each other along the z-direction;

[0007] The first component includes an inner ring magnet and an outer ring magnet arranged coaxially, with the outer ring magnet sleeved on the outside of the inner ring magnet;

[0008] The second component includes a first coil, an intermediate back iron, and a second coil arranged coaxially along the z-direction, wherein the first coil, the intermediate back iron, and the second coil are arranged in a ring between the inner ring magnet and the outer ring magnet.

[0009] The magnetization direction of both the inner ring magnet and the outer ring magnet is along their radial direction.

[0010] Optionally, the first component further includes a first back iron, in which a mounting groove is provided. The inner ring magnet, the outer ring magnet, and the second component are all located in the mounting groove. The outer ring magnet is connected to the groove wall of the mounting groove, and the second component is spaced apart from the bottom of the mounting groove.

[0011] Optionally, the first component further includes an inner ring sealing cover, an inner ring pressing block, an outer ring sealing cover, and an outer ring pressing block. The inner ring sealing cover is sleeved on the outside of the inner ring magnet. The inner ring pressing block is located at the end of the inner ring magnet away from the bottom of the mounting groove. The outer ring sealing cover at least covers the inner side of the outer ring magnet. The outer ring pressing block is located at the end of the outer ring magnet away from the bottom of the mounting groove.

[0012] Optionally, the first component further includes a second back iron connected to the bottom of the mounting slot, with the inner ring magnet sleeved on the outside of the second back iron.

[0013] Optionally, a first protrusion is provided on the wall of the mounting groove near the bottom of the groove, and the outer ring magnet is placed on the first protrusion. A second protrusion is provided on the outer side of the second back iron near the bottom of the mounting groove, and the inner ring magnet is placed on the second protrusion.

[0014] When viewed from above along the z-direction, the first boss and the second boss are spaced apart.

[0015] Optionally, the second component further includes:

[0016] A first magnet is located between the first coil and the intermediate back iron, with the first magnet and the first coil spaced apart and connected to the intermediate back iron;

[0017] A second magnet is located between the second coil and the intermediate back iron, with the second magnet and the second coil spaced apart and connected to the intermediate back iron;

[0018] The first magnet and the second magnet are magnetized in opposite directions, along the z-direction.

[0019] Optionally, the second component further includes:

[0020] The moving bracket is located between the inner ring magnet and the outer ring magnet. A third groove is provided on the outer side of the moving bracket. The first coil, the second coil, the first magnet, the second magnet and the intermediate back iron are all located in the third groove and connected to the moving bracket.

[0021] A coil sealing cover is fitted around the outer periphery of the mover bracket and covers the opening of the third groove.

[0022] Optionally, the inner ring magnet has a first thickness gradient region distributed in a ring around its axis, the thickness of the first thickness gradient region gradually increasing from its center to both sides along the z-direction.

[0023] Optionally, a first groove is provided on the outer surface of the inner ring magnet, which is distributed in a ring around its axis. The axial cross-section of the first groove is a V-shaped structure to form the first thickness gradient zone.

[0024] Optionally, the inner ring magnet is provided with a first hole distributed in a ring around its axis. The first hole penetrates the inner ring magnet radially to divide the inner ring magnet into an upper inner ring magnet and a lower inner ring magnet that are spaced apart along the z-direction.

[0025] Optionally, the outer ring magnet has a second thickness gradient region distributed in a ring around its axis, the thickness of the second thickness gradient region gradually increasing from its center to both sides along the z-direction.

[0026] Optionally, the inner surface of the outer ring magnet is provided with a second groove distributed in a ring around its axis, and the axial cross section of the second groove is a V-shaped structure to form the second thickness gradient zone.

[0027] Optionally, the outer ring magnet is provided with a second hole distributed in a ring around its axis. The second hole penetrates the outer ring magnet radially to divide the outer ring magnet into an upper outer ring magnet and a lower outer ring magnet that are spaced apart along the z-direction.

[0028] As described above, the magnetic levitation voice coil motor provided in this application has at least the following beneficial effects:

[0029] In the magnetic levitation voice coil motor of this application, the inner ring magnet and the outer ring magnet constitute the first component, and the first coil, the intermediate back iron, and the second coil constitute the second component. The magnetic levitation force generated between the second component and the first component can compensate for the gravity of the vertical micro-motion stage and the reverse force of the reed. The Lorentz force generated between the second component and the first component can drive the vertical micro-motion stage.

[0030] Within different vertical stroke ranges, the vertical resultant force of the magnetic levitation force and Lorentz force in the magnetic levitation voice coil motor varies linearly within a large displacement range of the vertical micro-motion stage, giving the magnetic levitation voice coil motor of this application constant stiffness characteristics. By adjusting the equivalent stiffness of the magnetic levitation voice coil motor, the forces applied by the magnetic levitation voice coil motor and the reed to the vertical micro-motion stage can be made to be of the same magnitude but opposite in direction. That is, the vertical resultant force of the two acting together on the vertical micro-motion stage tends to be a zero stiffness curve, thus effectively improving the heating problem of the magnetic levitation voice coil motor and improving the positioning accuracy of the vertical micro-motion stage.

[0031] Furthermore, the magnetic levitation voice coil motor of this application achieves the function of constant stiffness gravity compensation by using only an inner ring magnet, an outer ring magnet, and an intermediate back iron. Combined with the first coil and the second coil, it can achieve the function of constant stiffness vertical drive. The structure is simple and occupies little space.

[0032] In summary, the magnetic levitation voice coil motor of this application has the characteristics of low heat generation, low power consumption, simple structure, small space occupation, and constant stiffness within the stroke range. It realizes precise positioning of the vertical micro-motion stage and improves the overall integration and control accuracy of the equipment. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 The diagram shown is a structural schematic of a magnetic levitation voice coil motor provided in an embodiment of this application.

[0035] Figure 2 The diagram shown is a structural schematic of a magnetic levitation voice coil motor with a first back iron provided in Embodiment 1 of this application.

[0036] Figure 3 The diagram shown is a structural schematic of a magnetic levitation voice coil motor with a second back iron provided in Embodiment 1 of this application.

[0037] Figure 4 The diagram shown is a structural schematic of a magnetic levitation voice coil motor with a first boss provided in Embodiment 1 of this application.

[0038] Figure 5 The diagram shown is a structural schematic of a magnetic levitation voice coil motor with a motion support provided in Embodiment 1 of this application.

[0039] Figure 6The diagram shown is a structural schematic of a motion support in a magnetic levitation voice coil motor provided in Embodiment 1 of this application.

[0040] Figure 7 Displayed as Figure 5 The diagram shows the magnetic field lines inside the magnetic levitation voice coil motor.

[0041] Figure 8 Displayed as Figure 5 The force-displacement curve of the magnetic levitation voice coil motor is shown.

[0042] Figure 9 and Figure 10 The diagrams shown are schematic diagrams of two different magnetic levitation voice coil motors provided in Embodiment 2 of this application.

[0043] Figure 11 The diagram shown is a structural schematic of a magnetic levitation voice coil motor with a coil sealing cover provided in Embodiment 2 of this application.

[0044] Figure 12 The diagram shown is a structural schematic of a magnetic levitation voice coil motor provided in Embodiment 3 of this application.

[0045] Figure 13 and Figure 14 The diagrams shown are schematic representations of two different magnetic levitation voice coil motors with a first groove, as provided in Embodiment 3 of this application.

[0046] Figure 15 and Figure 16 The diagrams shown are schematic representations of two different magnetic levitation voice coil motors with a first aperture, as provided in Embodiment 3 of this application.

[0047] Figure 17 and Figure 18 The diagrams shown are schematic representations of two different magnetic levitation voice coil motors with a second groove, as provided in Embodiment 3 of this application.

[0048] Figure 19 and Figure 20 The diagrams shown are schematic representations of two different magnetic levitation voice coil motors with a second aperture, as provided in Embodiment 3 of this application.

[0049] Figure 21 Displayed as Figure 12 The diagram shows the magnetic field lines inside the magnetic levitation voice coil motor.

[0050] Figure 22 Displayed as Figure 12 The force-displacement curves of the magnetic levitation voice coil motor when different currents are applied are shown.

[0051] Figure 23 Displayed as Figure 12 The force-displacement curve of the magnetic levitation voice coil motor is shown.

[0052] Figure 24 Displayed as Figure 12 The graph shows the vertical resultant force of the magnetic levitation voice coil motor and the curves of the reed's reverse force versus displacement.

[0053] Figure 25 They are displayed as Figure 10 and Figure 12 The force-displacement curve of the magnetic levitation voice coil motor is shown.

[0054] Figure 26 The image shown is a top view of the inner and outer ring magnets along the z-direction, as provided in Embodiment 3 of this application.

[0055] Illustration of reference numerals in the attached diagram:

[0056] 10. First component; 111. Inner ring magnet; 1111. First thickness gradient zone; 1112. First groove; 1113. Upper inner ring magnet; 1114. Lower inner ring magnet; 1115. First aperture; 112. Outer ring magnet; 1121. Second thickness gradient zone; 1122. Second groove; 1123. Upper outer ring magnet; 1124. Lower outer ring magnet; 1125. Second aperture; 121. First back iron; 1211. Mounting groove; 1212. First boss; 122. Second back iron; 1221, Second boss; 131, Inner ring sealing cover; 132, Inner ring pressing block; 133, Outer ring sealing cover; 134, Outer ring pressing block; 20, Second assembly; 211, First magnet; 212, Second magnet; 221, Intermediate back iron; 231, First coil; 232, Second coil; 241, Motion bracket; 2401, Third groove; 2411, First annular groove; 2412, Second annular groove; 2413, Third annular groove; 251, Coil sealing cover. Detailed Implementation

[0057] To make the technical objectives, technical solutions, and technical effects of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of this application, it should be noted that the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with an implementation or example, which are included in at least one implementation or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same implementation or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more implementations or examples.

[0060] Reference Figure 1 This application provides a magnetic levitation voice coil motor, including a first component 10 and a second component 20 arranged at intervals between each other. With the axis of the first component 10 as the z-direction, the first component 10 and the second component 20 can move relative to each other in the z-direction. Optionally, the first component 10 and the second component 20 are arranged coaxially.

[0061] The first component 10 includes an inner ring magnet 111 and an outer ring magnet 112 arranged coaxially, with the outer ring magnet 112 sleeved on the outside of the inner ring magnet 111. The second component 20 includes a first coil 231, an intermediate back iron 221, and a second coil 232. The axial direction of the first coil 231, the intermediate back iron 221, and the second coil 232 is the z-direction. The first coil 231, the intermediate back iron 221, and the second coil 232 are arranged coaxially along the z-direction and are arranged in a ring around the axis of the first component 10 between the outer ring magnet 112 and the inner ring magnet 111. The magnetization direction of the outer ring magnet 112 and the inner ring magnet 111 is along their radial direction, and the relative positions of the first coil 231, the second coil 232, and the intermediate back iron 221 remain unchanged.

[0062] The magnetic fields generated by the inner ring magnet 111 and the outer ring magnet 112 can produce a magnetic levitation force along the z-direction on the intermediate back iron 221. Within the stroke range of the magnetic levitation voice coil motor, the magnetic levitation force on the intermediate back iron 221 is linearly related to the displacement. Therefore, through the magnetic levitation force, compensation for the gravity of the vertical micro-motion stage and the reverse force of the reed can be achieved without external energy input. When current is passed through the first coil 231 and the second coil 232, the first coil 231 and the second coil 232 cut the magnetic fields generated by the inner ring magnet 111 and the outer ring magnet 112, thereby generating a Lorentz force. The Lorentz force can drive the vertical micro-motion stage and also vertically position the movers in the first component 10 and the second component 20. The amplitude of the Lorentz force is related to the amplitude of the input current of the first coil 231 and the second coil 232.

[0063] During use, within different vertical stroke ranges, the vertical resultant force of the magnetic levitation force and Lorentz force generated by the magnetic levitation voice coil motor exhibits a linear relationship with displacement over a large stroke range, giving the magnetic levitation voice coil motor constant stiffness characteristics. A reed is positioned between the mover of the magnetic levitation voice coil motor and the external load. Within the stroke range of the magnetic levitation voice coil motor, the reverse force of the reed has a linear relationship with displacement. Therefore, by adjusting the equivalent stiffness of the magnetic levitation voice coil motor, the forces applied by the magnetic levitation voice coil motor and the reed on the vertical micro-motion stage can be made to be of equal magnitude but opposite direction. That is, the vertical resultant force applied by both on the vertical micro-motion stage tends towards a zero stiffness curve, achieving precise compensation for the gravity of the vertical micro-motion stage and the reverse force of the reed, improving the heating problem of the magnetic levitation voice coil motor, and enhancing the positioning accuracy of the vertical micro-motion stage.

[0064] To provide a more detailed explanation of the magnetic levitation voice coil motor of this application, the technical solutions in this application will be described below in conjunction with specific embodiments. It should be noted that, without conflict, the technical features and solutions in each embodiment can be used in combination.

[0065] Example 1

[0066] This embodiment provides a magnetic levitation voice coil motor, including a first component 10 and a second component 20 arranged at intervals between each other. The first component 10 and the second component 20 are coaxially arranged, with the axial direction of the first component 10 as the z-direction, and the first component 10 and the second component 20 can move relative to each other in the z-direction.

[0067] In this embodiment, one of the first component 10 and the second component 20 can serve as the mover of the magnetic levitation voice coil motor, and the other can serve as the stator of the magnetic levitation voice coil motor. Specifically, for example, the first component 10 is the stator and the second component 20 is the mover; or the second component 20 is the stator and the first component 10 is the mover; the mover can move relative to the stator along the z-direction.

[0068] Reference Figure 1 The first component 10 includes an inner ring magnet 111 and an outer ring magnet 112, which are coaxially arranged, with the outer ring magnet 112 sleeved on the outside of the inner ring magnet 111. Optionally, the inner ring magnet 111 and the outer ring magnet 112 are radially spaced apart, and their relative positions remain unchanged. Both the inner ring magnet 111 and the outer ring magnet 112 are gyroscopic structures, and their heights along the z-direction can be the same or different. The materials used to make the inner ring magnet 111 and the outer ring magnet 112 include rare-earth materials with high magnetic energy product, such as neodymium iron boron permanent magnets, samarium cobalt permanent magnets, or other suitable magnet structures.

[0069] The second component 20 includes a first coil 231, an intermediate back iron 221, and a second coil 232. The first coil 231, intermediate back iron 221, and second coil 232 are coaxially arranged sequentially along the z-direction and are arranged in a ring between an inner ring magnet 111 and an outer ring magnet 112. The magnetization direction of both the inner ring magnet 111 and the outer ring magnet 112 is along their radial direction. Optionally, the first coil 231 and the second coil 232 are symmetrically arranged about the intermediate back iron 221. Both the inner ring magnet 111 and the outer ring magnet 112 are cylindrical structures, and their magnetization directions are the same, for example, both from the inside to the outside or from the outside to the inside radially. The relative positions of the first coil 231, intermediate back iron 221, and second coil 232 remain unchanged. This can be achieved using a bracket or other suitable method to maintain the relative positions of the first coil 231, intermediate back iron 221, and second coil 232.

[0070] The magnetic fields generated by the inner ring magnet 111 and the outer ring magnet 112 produce a magnetic levitation force on the intermediate back iron 221. The first coil 231 and the second coil 232 cut the magnetic field to generate a Lorentz force. The vertical resultant force of the magnetic levitation force and the Lorentz force changes approximately linearly with displacement. Therefore, within the vertical stroke range of the magnetic levitation voice coil motor, the vertical actuator has constant stiffness characteristics. The reed is positioned between the mover of the magnetic levitation voice coil motor and the vertical micro stage. By adjusting the equivalent stiffness of the magnetic levitation voice coil motor and utilizing its constant stiffness characteristics, the forces applied by the magnetic levitation voice coil motor and the reed to the vertical micro stage can be made to be of the same magnitude but opposite in direction. This makes the vertical resultant force applied to the vertical micro stage tend towards a zero stiffness curve, thus improving the compensation accuracy for the gravity of the vertical micro stage and the reverse force of the reed, improving the heating problem of the magnetic levitation voice coil motor, and enabling precise positioning of the mover through the Lorentz force, thereby improving the control accuracy of the vertical micro stage.

[0071] In this embodiment, refer to Figure 2The first component 10 may further include a first back iron 121, in which a mounting groove 1211 is provided. Optionally, the first back iron 121 has a cylindrical structure, and the mounting groove 1211 is coaxially arranged with the first back iron 121, with the axial direction of the mounting groove 1211 being the z-direction. The material of the first back iron 121 is a high-permeability material or other suitable material. The inner ring magnet 111, the outer ring magnet 112, and the second component 20 are all located within the mounting groove 1211. Optionally, the outer ring magnet 112 is connected to the groove wall of the mounting groove 1211, and the second component 20 is spaced apart from the bottom of the mounting groove 1211. The outer ring magnet 112 can be fixedly connected to the groove wall of the mounting groove 1211, for example, by adhesive bonding or other suitable methods, so that the outer ring magnet is fixedly connected to the groove wall of the mounting groove 1211. By setting the first back iron 121, the magnetic field distribution of the inner ring magnet 111 and the space surrounding the inner ring magnet 111 can be improved, thereby improving the performance of the magnetic levitation voice coil motor.

[0072] In this embodiment, refer to Figure 3 The first component 10 may further include a second back iron 122, which is located within the mounting groove 1211 and connected to the bottom of the groove. The inner ring magnet 111 is sleeved on the outside of the second back iron 122. The material of the second back iron 122 may be a high-permeability material or other suitable material. The second back iron 122 may be fixedly connected to the bottom of the mounting groove 1211, or the first back iron 121 and the second back iron 122 may be an integral structure. The second back iron 122 is used to improve the magnetic field distribution in the space surrounding the inner ring magnet 111 and improve the performance of the magnetic levitation voice coil motor. Optionally, the second back iron 122 has a cylindrical structure, and the height of the second back iron 122 along the z-direction is greater than the height of the inner ring magnet 111 along the z-direction to ensure the improvement effect on the magnetic field.

[0073] In an optional embodiment, refer to Figure 4A first boss 1212 is provided on the wall of the mounting groove 1211, and an outer ring magnet 112 is placed on the first boss 1212. Optionally, the first boss 1212 is a ring structure, which is arranged around the axis of the mounting groove 1211 at one end of the mounting groove 1211 near its bottom. The first boss 1212 can be fixedly connected to the bottom and / or wall of the mounting groove 1211, or the first boss 1212 and the first back iron 121 can also adopt an integral structure. A second boss 1221 is provided on the outer surface of the second back iron 122. The inner ring magnet 111 is placed on the second boss 1221. Optionally, the second boss 1221 is a ring structure. The second boss 1221 is arranged around the axis of the second back iron 122 at one end of the second back iron 122 near the bottom of the mounting groove 1211. The second boss 1221 can be fixedly connected to the second back iron 122 by bonding or other suitable means, or the second boss 1221 and the second back iron 122 can also adopt an integral structure. In the magnetic levitation voice coil motor viewed from above along the z-direction, the first boss 1212 and the second boss 1221 are spaced apart, that is, the first boss 1212 and the second boss 1221 are spaced apart along the radial direction of the mounting groove 1211, so as to provide sufficient movement space for the first component 10 and the second component 20 to move relative to each other along the z-direction. By setting the first boss 1212 and the second boss 1221, it is also convenient to install the outer ring magnet 112 and the inner ring magnet 111.

[0074] In this embodiment, refer to Figure 5 The second component 20 also includes a motion support 241. The first coil 231, the second coil 232, and the intermediate back iron 221 are all sleeved on the outside of the motion support 241 and connected to the motion support 241, so that the relative positions of the first coil 231, the second coil 232, and the intermediate back iron 221 remain unchanged. Optionally, refer to Figure 6 A third groove 2401 is provided on the outer surface of the motion support 241. The third groove 2401 is distributed in a ring around the axis of the motion support 241. The first coil 231, the second coil 232 and the intermediate back iron 221 are all located in the third groove 2401 of the motion support 241 and are connected to the bottom and / or wall of the third groove 2401 so that the first coil 231, the second coil 232 and the intermediate back iron 221 are connected to the motion support 241. The first coil 231 and the second coil 232 can be directly connected to the motion support 241, or they can be connected through a coil support.

[0075] In an optional embodiment, refer to Figure 6The third groove 2401 of the motion support 241 includes a first annular groove 2411, a second annular groove 2412, and a third annular groove 2413, which are sequentially spaced along the z-direction. The first annular groove 2411, the second annular groove 2412, and the third annular groove 2413 are all annularly distributed around the axis of the motion support 241. The first coil 231 is located within the first annular groove 2411, the intermediate back iron 221 is located within the second annular groove 2412, and the second coil 232 is located within the third annular groove 2413. The structural dimensions of the first annular groove 2411, the second annular groove 2412, and the third annular groove 2413 can be set according to actual needs.

[0076] Figure 7 It shows Figure 5 The diagram shows the magnetic field lines inside the magnetic levitation voice coil motor. Figure 7 This is a half-section view of a magnetic levitation voice coil motor cut radially from its axis. The z-axis in the figure is the axis of the magnetic levitation voice coil motor. The magnetic field inside the magnetic levitation voice coil motor forms a closed loop through the inner ring magnet 111, the first back iron 121, the outer ring magnet 112, the second component 20, and the inner ring magnet 111 in sequence. The magnetic field generated between the inner ring magnet 111 and the outer ring magnet 112 can generate a magnetic levitation force along the z-direction on the intermediate back iron 221.

[0077] Figure 5 In the magnetic levitation voice coil motor shown, the outer ring magnet 112 and the inner ring magnet 111 are made to have the same height along the z-direction, and the first coil 231 and the second coil 232 are symmetrically arranged about the intermediate back iron 221. Figure 8 The force versus displacement curves of the magnetic levitation voice coil motor are shown. In this embodiment, the zero point is defined as the position where the center plane of the inner ring magnet 111 along the z-direction coincides with the center plane of the intermediate back iron 221 along the z-direction. Figure 8 In the diagram, the solid line at the bottom represents the curve of the levitation force versus displacement of the maglev voice coil motor; the short dashed line above represents the curve of the Lorentz force versus displacement of the maglev voice coil motor; and the long dashed line above represents the curve of the vertical resultant force of the levitation force and the Lorentz force versus displacement of the maglev voice coil motor. This is based on simulation calculations and... Figure 8 It can be seen that within the vertical stroke range of -6mm to 4mm, the thrust constant generated by the magnetic levitation voice coil motor is approximately 28.5N / A. The magnetic levitation force and the vertical resultant force change with displacement in an approximately linear manner. The thrust constant is the Lorentz force of the magnetic levitation voice coil motor when the current is input per unit.

[0078] In summary, the magnetic levitation voice coil motor of this embodiment exhibits a near-linear relationship between the magnetic levitation force and the vertical resultant force as displacement changes over a large stroke range, giving it constant stiffness characteristics over this range. By adjusting the equivalent stiffness of the magnetic levitation voice coil motor, the resultant stiffness of the reed and the magnetic levitation voice coil motor can be brought close to zero, effectively improving the heating problem of the magnetic levitation voice coil motor and enhancing the positioning accuracy of the vertical micro-motion stage. Furthermore, the magnetic levitation voice coil motor of this embodiment achieves constant stiffness gravity compensation function using only the inner ring magnet 111, the outer ring magnet 112, and the intermediate back iron 221. Combined with the first coil 231 and the second coil 232, it can achieve constant stiffness vertical drive function. It features low heat generation, low power consumption, simple structure, small footprint, and constant stiffness within the stroke range, improving the overall integration and control accuracy of the equipment.

[0079] Example 2

[0080] This embodiment provides a magnetic levitation voice coil motor, which also includes a first component 10 and a second component 20. The similarities with Embodiment 1 will not be repeated. The difference is that in the magnetic levitation voice coil motor of this embodiment, the second component 20 also includes a first magnet 211 and a second magnet 212.

[0081] Reference Figure 9 and Figure 10 A first magnet 211 is located between the first coil 231 and the intermediate back iron 221, and is connected to the intermediate back iron 221; a second magnet 212 is located between the second coil 232 and the intermediate back iron 221, and is connected to the intermediate back iron 221. The magnetization directions of the first magnet 211 and the second magnet 212 are opposite and along the z-direction; for example, the magnetization direction of the first magnet 211 is upward along the z-direction, and the magnetization direction of the second magnet 212 is downward along the z-direction; or the magnetization direction of the first magnet 211 is downward along the z-direction, and the magnetization direction of the second magnet 212 is upward along the z-direction. By setting the first magnet 211 and the second magnet 212, the magnetic field strength distributed within the magnetic levitation voice coil motor can be enhanced, enabling the magnetic levitation voice coil motor to provide greater Lorentz force and magnetic levitation force, thereby enhancing the motor's output thrust and improving its operating performance.

[0082] In an optional embodiment, the first magnet 211 is spaced apart from the first coil 231, and the second magnet 212 is spaced apart from the second coil 232, so as to provide insulation space for the first coil 231 and the second coil 232. The first magnet 211 and the second magnet 212 are symmetrically arranged on opposite sides of the intermediate back iron 221 along the z-direction, and the first magnet 211 and the second magnet 212 have opposite magnetization directions along the z-direction, which helps to improve the distribution of the magnetic field inside the motor, so that the vertical resultant force and displacement of the magnetic levitation voice coil motor have better linearity within the stroke range, thereby improving the control accuracy of the magnetic levitation voice coil motor and the compensation accuracy of the vertical micro-motion stage gravity and the reed directional force.

[0083] In an optional embodiment, the second component 20 further includes a motion support 241. A third groove 2401 is provided on the outer surface of the motion support 241. The third groove 2401 includes a first annular groove 2411, a second annular groove 2412, and a third annular groove 2413, which are sequentially spaced along the z-direction. The first magnet 211, the intermediate back iron 221, and the second magnet 212 are located within the second annular groove 2412 and connected to the motion support 241. Optionally, the first magnet 211, the intermediate back iron 221, and the second magnet 212 are fixedly connected to the motion support 241 by adhesive bonding or other suitable methods.

[0084] In an optional embodiment, refer to Figure 11 The second component 20 also includes a coil sealing cover 251, which is fitted around the outer periphery of the motion bracket 241 and covers the opening of the third groove 2401 to seal the first magnet 211, the second magnet 212, the first coil 231, and the second coil 232 within the third groove 2401. Optionally, the coil sealing cover 251 is fixedly connected to the motion bracket 241. The coil sealing cover 251 can be fixedly connected to the motion bracket 241, for example, by welding or other suitable means, thereby sealing the first magnet 211, the second magnet 212, the first coil 231, and the second coil 232 within the third groove 2401 to enhance the vacuum adaptability of the magnetic levitation voice coil motor.

[0085] In an optional embodiment, refer to Figure 11The first component 10 also includes an inner ring sealing cover 131, an inner ring pressing block 132, an outer ring sealing cover 133, and an outer ring pressing block 134, for sealing the inner ring magnet 111 and the outer ring magnet 112 to improve the vacuum applicability of the magnetic levitation voice coil motor; the inner ring sealing cover 131 is sleeved on the outside of the inner ring magnet 111, and the inner ring pressing block 132 is located at the end of the inner ring magnet 111 away from the bottom of the mounting groove 1211; the outer ring sealing cover 133 at least covers the inner side of the outer ring magnet 112, and the outer ring pressing block 134 is located at the end of the outer ring magnet 112 away from the bottom of the mounting groove 1211.

[0086] Furthermore, a second boss 1221 is provided around the outer surface of the second back iron 122. The inner ring magnet 111 is placed on the second boss 1221. The inner ring sealing cover 131 covers the outer surface of the inner ring magnet 111 and at least part of the second boss 1221 to seal the inner ring magnet 111. The inner ring pressure block 132 is fixedly connected to the inner ring sealing cover 131, and the inner ring sealing cover 131 is fixedly connected to the second boss 1221 to seal the inner ring magnet 111. The inner ring sealing cover 131 can be fixedly connected to the inner ring pressure block 132 and the second boss 1221 by welding or other suitable means.

[0087] Furthermore, a first boss 1212 is provided on the inner side of the first back iron 121 near the bottom of the mounting groove 1211. The outer ring magnet 112 is placed on the first boss 1212. The outer ring sealing cover 133 covers the inner side of the outer ring magnet 112 and at least part of the first boss 1212 to seal the outer ring magnet 112. The outer ring pressure block 134 is fixedly connected to the first back iron 121 and the outer ring sealing cover 133 respectively. The outer ring sealing cover 133 is fixedly connected to the first boss 1212. This can be achieved by welding or other suitable methods to fix the outer ring sealing cover 133 to the first boss 1212 and the outer ring pressure block 134, as well as to the outer ring pressure block 134 and the first back iron 121 respectively.

[0088] Example 3

[0089] This embodiment provides a magnetic levitation voice coil motor, which also includes a first component 10 and a second component 20. The similarities with Embodiment 1 or Embodiment 2 will not be repeated, and the differences are as follows.

[0090] In this embodiment, refer to Figures 12 to 14 , Figure 14This is a half-section view of a magnetic levitation voice coil motor cut radially from its axis. The z-axis in the figure is the axis of the magnetic levitation voice coil motor. The inner ring magnet 111 has a first thickness gradient region 1111 distributed in a ring around its axis. The thickness of the first thickness gradient region 1111 gradually increases from its center to both sides along the z-direction. Optionally, the first thickness gradient region 1111 has a first center plane along the z-direction, that is, the normal of the first center plane is the z-direction. The first thickness gradient region 1111 is symmetrically arranged about the first center plane along the z-direction. The thickness of the first thickness gradient region 1111 gradually increases from the first center plane to both sides along its radial direction. By setting the first thickness gradient region 1111, the magnetic field distribution inside the magnetic levitation voice coil motor can be improved, making the magnetic field gradient distribution more uniform, realizing constant stiffness output over a large stroke range, and also improving the equivalent stiffness and magnetic levitation force of the magnetic levitation voice coil motor.

[0091] In an optional embodiment, a first groove 1112 is provided on the outer surface of the inner ring magnet 111, and the first groove 1112 is distributed in a ring around the axis of the inner ring magnet 111 on the outer surface of the inner ring magnet 111. Optionally, the axial cross-section of the first groove 1112 can be a V-shaped structure, an arc-shaped structure, a parabolic structure, or other suitable structure with the opening facing the outer ring magnet 112, to form a first thickness gradient region 1111; the axial cross-section of the first groove 1112 can also be a bowl-shaped structure with the opening facing the outer ring magnet 112. Wherein, the axial cross-section of the first groove 1112 is the cross-section of the first groove 1112 obtained by the plane passing through the axis of the inner ring magnet 111, and preferably, the axial cross-section of the first groove 1112 is a V-shaped structure.

[0092] In an optional embodiment, refer to Figure 15 and Figure 16 , Figure 15 and Figure 16 All are half-section views of the magnetic levitation voice coil motor cut radially from the axis. The z-axis in the figure is the axis of the magnetic levitation voice coil motor. The inner ring magnet 111 can also be provided with a number of first holes 1115. The number of first holes 1115 are distributed sequentially and spaced apart along the z-direction and are distributed in a ring around the axis of the inner ring magnet 111. The number of first holes 1115 penetrate the inner ring magnet 111 radially to divide the inner ring magnet 111 into a number of inner ring sub-magnets distributed sequentially and spaced apart along the z-direction.

[0093] Furthermore, a first aperture 1115 can be provided in the inner ring magnet 111. The first aperture 1115 is distributed in a ring around the axis of the inner ring magnet 111 and penetrates the inner ring magnet 111 radially, thereby dividing the inner ring magnet 111 into two inner ring sub-magnets spaced apart along the z-direction, and respectively denoted as the upper inner ring magnet 1113 and the lower inner ring magnet 1114. The inner ring magnet 111 can have both the first aperture 1115 and the first groove 1112, or only one of the first aperture 1115 and the first groove 1112. Using the first aperture 1115 to divide the inner ring magnet 111 into inner ring sub-magnets spaced apart along the z-direction can also improve the magnetic field distribution in the magnetic levitation voice coil motor, making the magnetic field gradient distribution more uniform, achieving constant stiffness output over a large stroke range, and also improving the equivalent stiffness and magnetic levitation force of the magnetic levitation voice coil motor.

[0094] In this embodiment, refer to Figure 12 , Figure 17 and Figure 18 , Figure 17 and Figure 18 All figures are half-section views of the magnetic levitation voice coil motor cut radially from its axis. The z-axis in the figures represents the axis of the magnetic levitation voice coil motor. A second thickness gradient region 1121 can be provided in the outer ring magnet 112. The second thickness gradient region 1121 is distributed in a ring around the axis of the outer ring magnet 112. The thickness of the second thickness gradient region 1121 gradually increases from its center to both sides along the z-direction. Optionally, the second thickness gradient region 1121 has a second center surface along the z-direction. The second thickness gradient region 1121 is symmetrically arranged about the second center surface along the z-direction, and the thickness of the second thickness gradient region 1121 gradually increases from the second center surface to both sides along its radial direction. By providing the second thickness gradient region 1121, the magnetic field distribution inside the magnetic levitation voice coil motor can be improved, making the magnetic field gradient distribution more uniform, achieving constant stiffness output over a large stroke range, and also improving the equivalent stiffness and magnetic levitation force of the magnetic levitation voice coil motor.

[0095] In an optional embodiment, a second groove 1122 is provided on the inner surface of the outer ring magnet 112, and the second groove 1122 is distributed in a ring around the axis of the outer ring magnet 112 on the inner surface of the outer ring magnet 112. Optionally, the axial cross-section of the second groove 1122 can be a V-shaped structure, an arc-shaped structure, a parabolic structure, or other suitable structure with the opening facing the inner ring magnet 111, to form a second thickness gradient region 1121; the axial cross-section of the second groove 1122 can also be a bowl-shaped structure with the opening facing the inner ring magnet 111. Wherein, the axial cross-section of the second groove 1122 is the cross-section of the second groove 1122 obtained by the plane passing through the axis of the outer ring magnet 112, and preferably, the axial cross-section of the second groove 1122 is a V-shaped structure.

[0096] In an optional embodiment, refer to Figure 19 and Figure 20 , Figure 19 and Figure 20 All are half-section views of the magnetic levitation voice coil motor cut radially from the axis. The z-axis in the figure is the axis of the magnetic levitation voice coil motor. The outer ring magnet 112 can also be provided with a number of second holes 1125. The number of second holes 1125 are distributed sequentially at intervals along the z-direction and are distributed in a ring around the axis of the outer ring magnet 112. The second holes 1125 penetrate the outer ring magnet 112 radially to divide the outer ring magnet 112 into a number of outer ring sub-magnets distributed sequentially at intervals along the z-direction.

[0097] Furthermore, a second aperture 1125 can be provided in the outer ring magnet 112. The second aperture 1125 is distributed in a ring around the axis of the outer ring magnet 112 and penetrates the outer ring magnet 112 radially, dividing the outer ring magnet 112 into two outer ring sub-magnets spaced apart along the z-direction, respectively denoted as the upper outer ring magnet 1123 and the lower outer ring magnet 1124. The outer ring magnet 112 can have both the second aperture 1125 and the second groove 1122, or only one of the second aperture 1125 and the second groove 1122. Using the second aperture 1125 to divide the outer ring magnet 112 into outer ring sub-magnets spaced apart along the z-direction can also improve the magnetic field distribution in the magnetic levitation voice coil motor, making the magnetic field gradient distribution more uniform, achieving constant stiffness output over a large stroke range, and also improving the equivalent stiffness and magnetic levitation force of the magnetic levitation voice coil motor.

[0098] Figure 21 It shows Figure 12 The diagram shows the magnetic field lines inside the magnetic levitation voice coil motor. Figure 21 This is a half-section view of a magnetic levitation voice coil motor cut radially from its axis. The z-axis in the figure is the axis of the magnetic levitation voice coil motor. Figure 21 In the first magnet 211, the magnetic field generated passes through the first coil 231, the inner ring magnet 111, the second back iron 122, the first back iron 121, the outer ring magnet 112, the middle back iron 221, and the first magnet 211 in sequence to form a closed loop. The magnetic field generated by the second magnet passes through the second coil 232, the inner ring magnet 111, the second back iron 122, the first back iron 121, the outer ring magnet 112, the middle back iron 221, and the second magnet 212 in sequence to form a closed loop. This results in a magnetic levitation force along the z-direction between the first component 10 and the second component 20 to compensate for the gravity of the vertical micro-motion stage and the reverse force of the reed. The first coil 231 and the second coil 232 cut the magnetic field lines to generate a Lorentz force, thereby driving the vertical movement of the vertical micro-motion stage. The amplitude of the Lorentz force is related to the amplitude of the current flowing through the first coil 231 and the second coil 232.

[0099] Figure 22 It shows Figure 12 The curves shown represent the vertical resultant force of the magnetic levitation force and the Lorentz force of the magnetic levitation voice coil motor versus the displacement. Figure 22 In the diagram, curve 011 represents the relationship between the levitation force and displacement of the magnetic levitation voice coil motor; curve 012 represents the relationship between the vertical resultant force and displacement when a 0.5A current is applied to the magnetic levitation voice coil motor; curve 013 represents the relationship between the vertical resultant force and displacement when a 1A current is applied to the magnetic levitation voice coil motor; curve 014 represents the relationship between the vertical resultant force and displacement when a -0.5A current is applied to the magnetic levitation voice coil motor; and curve 015 represents the relationship between the vertical resultant force and displacement when a -1A current is applied to the magnetic levitation voice coil motor. Figure 22 It can be seen that when different currents are applied to the magnetic levitation voice coil motor, the vertical resultant force and displacement of the magnetic levitation voice coil motor have a linear relationship within the long stroke range, and the curves of vertical resultant force and displacement have the same or approximately the same slope, that is, the magnetic levitation voice coil motor has constant stiffness characteristics within the long stroke range.

[0100] Figure 23 It shows Figure 12 The force-displacement curve of the magnetic levitation voice coil motor is shown. Figure 23 In the diagram, the lower short dashed line represents the curve of levitation force versus displacement of the magnetic levitation voice coil motor; the upper solid line represents the curve of Lorentz force versus displacement of the magnetic levitation voice coil motor; and the upper long dashed line represents the curve of the vertical resultant force of the Lorentz force and magnetic levitation force versus displacement. This is based on simulation calculations and... Figure 23 It can be seen that within the large stroke range of -5mm to 5mm, the thrust constant of the magnetic levitation voice coil motor is approximately 28.1N / A, and the magnetic levitation force and vertical resultant force of the magnetic levitation voice coil motor have a linear relationship with the displacement within the stroke range. The thrust constant is the Lorentz force of the magnetic levitation voice coil motor when the input current is unit.

[0101] Figure 24 It shows Figure 12 The curves shown represent the vertical resultant force of the magnetic levitation voice coil motor and the reverse force of the reed relative to the displacement. Figure 24 In the diagram, the solid line represents the curve of the vertical resultant force versus displacement of the magnetic levitation voice coil motor; the long dashed line represents the curve of the reverse force versus displacement of the reed; and the approximately horizontal short dashed line represents the curve of the resultant force versus displacement of the vertical resultant force of the magnetic levitation voice coil motor and the reverse force of the reed. Figure 24 It is known that by adjusting the equivalent stiffness of the magnetic levitation voice coil motor, the forces exerted by the magnetic levitation voice coil motor and the reed on the vertical micro-motion stage can be made equal in magnitude and opposite in direction, that is, the combined stiffness of the magnetic levitation voice coil motor and the reed approaches zero, which can effectively improve the heating problem of the magnetic levitation voice coil motor.

[0102] Figure 25 They are shown respectively Figure 10 and Figure 12 The force-displacement curve of the magnetic levitation voice coil motor is shown. Figure 25In the middle, curve 021 is Figure 12 The curves shown represent the relationship between the magnetic levitation force and displacement of the magnetic levitation voice coil motor. Curve 022 is... Figure 12 The curves shown are of the Lorentz force versus displacement of the magnetic levitation voice coil motor, curve 023 being... Figure 12 The curve shown represents the vertical resultant force and displacement of the magnetic levitation force and Lorentz force of the magnetic levitation voice coil motor. Curve 024 is... Figure 10 The curves shown represent the magnetic levitation force versus displacement of the magnetic levitation voice coil motor; curve 025 is... Figure 10 The curves shown are of the Lorentz force versus displacement of the magnetic levitation voice coil motor, curve 026 being... Figure 10 The curves showing the vertical resultant force of the magnetic levitation force and Lorentz force versus displacement in a magnetic levitation voice coil motor are shown. Figure 25 It is known that within the large stroke range of -5mm to 5mm, both types of magnetic levitation voice coil motors have constant stiffness characteristics. By setting a first thickness gradient region 1111 and / or a second thickness gradient region 1121 in the magnetic levitation voice coil motor, the magnetic levitation force of the magnetic levitation voice coil motor can be enhanced and the equivalent stiffness of the magnetic levitation voice coil motor can be improved without changing or substantially changing the Lorentz force of the magnetic levitation voice coil motor.

[0103] In an optional embodiment, refer to Figure 26 Both the inner ring magnet 111 and the outer ring magnet 112 may include a plurality of tile-shaped magnet structures. The plurality of tile-shaped magnet structures surround the outer periphery of the second back iron 122, and adjacent magnet structures are interconnected to form the inner ring magnet 111. The plurality of tile-shaped magnet structures surround the inner side of the mounting groove 1211, and adjacent magnet structures are interconnected to form the outer ring magnet 112.

[0104] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify, alter, or combine the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A magnetic levitation voice coil motor, characterized in that, It includes a first component (10) and a second component (20) spaced apart from each other, with the axis of the first component (10) as the z-direction, and the first component (10) and the second component (20) can move relative to each other along the z-direction; The first component (10) includes an inner ring magnet (111) and an outer ring magnet (112) arranged coaxially, wherein the outer ring magnet (112) is sleeved on the outside of the inner ring magnet (111); The second component (20) includes a first coil (231), an intermediate back iron (221), and a second coil (232) arranged coaxially along the z-direction. The first coil (231), the intermediate back iron (221), and the second coil (232) are arranged in a ring between the inner ring magnet (111) and the outer ring magnet (112). The magnetization direction of both the inner ring magnet (111) and the outer ring magnet (112) is along their radial direction.

2. The magnetic levitation voice coil motor according to claim 1, characterized in that, The first component (10) further includes a first back iron (121), in which a mounting groove (1211) is provided. The inner ring magnet (111), the outer ring magnet (112) and the second component (20) are all located in the mounting groove (1211). The outer ring magnet (112) is connected to the groove wall of the mounting groove (1211). The second component (20) is spaced apart from the bottom of the mounting groove (1211).

3. The magnetic levitation voice coil motor according to claim 2, characterized in that, The first component (10) further includes an inner ring sealing cover (131), an inner ring pressing block (132), an outer ring sealing cover (133), and an outer ring pressing block (134). The inner ring sealing cover (131) is sleeved on the outside of the inner ring magnet (111). The inner ring pressing block (132) is located at one end of the inner ring magnet (111) away from the bottom of the mounting groove (1211). The outer ring sealing cover (133) covers at least the inner side of the outer ring magnet (112). The outer ring pressing block (134) is located at one end of the outer ring magnet (112) away from the bottom of the mounting groove (1211).

4. The magnetic levitation voice coil motor according to claim 2, characterized in that, The first component (10) further includes a second back iron (122) connected to the bottom of the mounting groove (1211), and the inner ring magnet (111) is sleeved on the outside of the second back iron (122).

5. The magnetic levitation voice coil motor according to claim 4, characterized in that, The mounting groove (1211) has a first boss (1212) on the groove wall near the bottom end of the groove, and the outer ring magnet (112) is placed on the first boss (1212). The second back iron (122) has a second boss (1221) on the outer side surface near the bottom end of the mounting groove (1211), and the inner ring magnet (111) is placed on the second boss (1221). When viewed from above along the z-direction, the first boss (1212) and the second boss (1221) are distributed at intervals.

6. The magnetic levitation voice coil motor according to claim 1, characterized in that, The second component (20) also includes: The first magnet (211) is located between the first coil (231) and the intermediate back iron (221), with the first magnet (211) and the first coil (231) spaced apart and connected to the intermediate back iron (221). The second magnet (212) is located between the second coil (232) and the intermediate back iron (221). The second magnet (212) is spaced apart from the second coil (232) and connected to the intermediate back iron (221). The first magnet (211) and the second magnet (212) are magnetized in opposite directions along the z-direction.

7. The magnetic levitation voice coil motor according to claim 6, characterized in that, The second component (20) also includes: The motion support (241) is located between the inner ring magnet (111) and the outer ring magnet (112). A third groove (2401) is provided on the outer side of the motion support (241). The first coil (231), the second coil (232), the first magnet (211), the second magnet (212) and the intermediate back iron (221) are all located in the third groove (2401) and connected to the motion support (241). The coil sealing cover (251) is fitted around the outer periphery of the motion bracket (241) and covers the opening of the third groove (2401).

8. The magnetic levitation voice coil motor according to claim 1, characterized in that, The inner ring magnet (111) has a first thickness gradient region (1111) distributed in a ring around its axis, and the thickness of the first thickness gradient region (1111) gradually increases from its center to both sides along the z direction.

9. The magnetic levitation voice coil motor according to claim 8, characterized in that, The outer surface of the inner ring magnet (111) is provided with a first groove (1112) distributed in a ring around its axis. The axial cross section of the first groove (1112) is a V-shaped structure to form the first thickness gradient region (1111).

10. The magnetic levitation voice coil motor according to claim 1, characterized in that, The inner ring magnet (111) is provided with a first hole (1115) distributed in a ring around its axis. The first hole (1115) penetrates the inner ring magnet (111) radially to divide the inner ring magnet (111) into an inner ring upper magnet (1113) and an inner ring lower magnet (1114) distributed at intervals along the z direction.

11. The magnetic levitation voice coil motor according to claim 1, characterized in that, The outer ring magnet (112) has a second thickness gradient region (1121) distributed in a ring around its axis, the thickness of the second thickness gradient region (1121) gradually increasing from its center to both sides along the z direction.

12. The magnetic levitation voice coil motor according to claim 11, characterized in that, The inner side of the outer ring magnet (112) is provided with a second groove (1122) distributed in a ring around its axis. The axial cross section of the second groove (1122) is a V-shaped structure to form the second thickness gradient zone (1121).

13. The magnetic levitation voice coil motor according to claim 1, characterized in that, The outer ring magnet (112) is provided with a second hole (1125) distributed in a ring around its axis. The second hole (1125) penetrates the outer ring magnet (112) radially to divide the outer ring magnet (112) into an upper outer ring magnet (1123) and a lower outer ring magnet (1124) distributed at intervals along the z-direction.

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