Voice coil motor

Abstract

The invention provides a voice coil motor. The voice coil motor comprises a base, a stator assembly and a rotor assembly. The stator assembly comprises a coil assembly and an adjusting assembly, the coil assembly comprises a coil support and a coil, the coil support is cylindrical and is installed on the base, and the coil is wound on the outer side wall of the coil support. The adjusting assembly is arranged in the coil support and comprises a cylindrical adjusting support and adjusting magnetic steel installed on the adjusting support in a sleeving mode, and the adjusting support is connected with the base in the mode that the position can be adjusted in the axial direction. The mover assembly comprises a mover support and mover magnetic steel installed on the mover support, and the mover magnetic steel is arranged on the outer side of the stator assembly in a sleeving mode. According to the voice coil motor, the adjusting magnetic steel capable of moving in the axial direction is arranged in the stator assembly, the axial position of the adjusting magnetic steel is changed, the magnetic levitation force is adjusted, the gravity compensation range is expanded, the burden of lorentz force generated by coil electrification for levitation compensation is shared, coil current stability is kept, heating is reduced, precision is improved, and the response speed is increased; and the size of the motor is not increased.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing and testing, and in particular, to a voice coil motor. Background Art

[0002] In the semiconductor manufacturing and testing field, many high-precision motion equipment, such as lithography machines, high-precision machine tools, and robotic arms, require high isolation from external vibrations and disturbances, especially in vacuum environments. Therefore, magnetic levitation gravity compensators are needed to compensate for gravity and achieve active vibration isolation. Existing magnetic levitation gravity compensators are mainly divided into passive and active types.

[0003] In existing technology, passive magnetic levitation gravity compensators primarily consist of stator magnets and mover magnets. Due to their fixed structure, their magnetic levitation force is largely unadjustable. However, most applications require adjustable magnetic levitation force, limiting the application of these passive magnetic levitation gravity compensators. Furthermore, increasing the magnetic levitation force of passive magnetic levitation gravity compensators typically involves increasing the size of the magnetic float magnets, which requires a complete redesign and increases the mass of the float. This not only limits their versatility but also makes them unsuitable for applications with size restrictions and high magnetic levitation force requirements.

[0004] Active magnetic levitation gravity compensators include not only stator and mover magnets but also energized coils. These coils generate a Lorentz force that works in conjunction with the magnetic levitation force to compensate for gravity. However, if the gravity to be balanced increases, this can only be achieved by increasing the coil current. This generates significant heat, which can lead to significant thermal deformation of the platform, deteriorating the system's dynamic characteristics, and reducing positioning accuracy.

[0005] As a zero-transmission drive mechanism, the magnetic levitation voice coil motor has a structure similar to that of an active magnetic levitation gravity compensator. It uses magnetic levitation to suspend the actuator in mid-air, eliminating the need for mechanical contact and enabling axial micro-movement. It is suitable for vacuum environments, and because the axial magnetic levitation compensates for gravity, it can reduce motor heating to a certain extent.

[0006] Existing magnetic levitation voice coil motors have certain limitations. The fixed structure of their stator and mover permanent magnets means that when the coil is unpowered, the magnetic levitation force generated by their interaction remains essentially constant. When the weight of the axially moving load driven by the magnetic levitation voice coil motor increases, the magnetic levitation force may be insufficient to maintain the load's levitation when the coil is unpowered. In this case, the only way to achieve levitation compensation is to increase the Lorentz force by increasing the coil current. This means that the Lorentz force not only drives the load's axial motion but also provides levitation compensation. This approach increases the heat generated by the magnetic levitation voice coil motor and slows the system's response speed.

[0007] Furthermore, some levitation voice coil motors increase the size of the permanent magnets in the actuator to enhance the magnetic levitation force, in order to drive heavier loads and achieve axial motion. However, this approach increases the size and mass of the levitation voice coil motor, which in turn affects the system's response speed. Furthermore, the large size of the levitation voice coil motor also limits its application. Summary of the Invention

[0008] The purpose of the present application is to provide a voice coil motor, in which a stator assembly is provided with an axially movable adjustable magnet. By changing the axial position of the adjustable magnet, the size of the magnetic buoyancy force is adjusted, the gravity compensation range is expanded, and the burden of the Lorentz force generated by the coil being energized for suspension compensation is shared, thereby maintaining the coil current stable, reducing heat, improving accuracy and response speed, and broadening the application scenarios without increasing the size of the motor.

[0009] The present application provides a voice coil motor, comprising a base, a stator assembly and a mover assembly. The direction of movement of the mover assembly is axial, and the direction perpendicular to the axial direction is radial. The stator assembly includes a coil assembly and an adjustment assembly, and the coil assembly includes a coil bracket and a coil. The coil bracket is cylindrical and its bottom is mounted on the base, and the coil is wound on the outer wall of the coil bracket. The adjustment assembly is placed inside the coil bracket, and includes a cylindrical adjustment bracket and an adjustment magnet mounted on the adjustment bracket; wherein the adjustment bracket is connected to the base in a manner that can adjust its position along the axial direction. The mover assembly includes a mover bracket and a mover magnet mounted on the mover bracket. The mover magnet is cylindrical and is mounted on the outside of the stator assembly.

[0010] In an implementable solution, the magnetizing direction of the regulating magnetic steel is along the axial direction, and the magnetizing direction of the mover magnetic steel is along the radial direction.

[0011] In one feasible solution, the adjustment assembly further includes a fixed magnet, which is fixedly mounted on the inner bottom of the coil bracket, and is sleeved on the outer side of the adjustment bracket and is located below the adjustment magnet; wherein relative sliding is maintained between the fixed magnet and the adjustment bracket.

[0012] In an implementable solution, the sliding range between the adjustable magnetic steel and the fixed magnetic steel is H, wherein the range of H is 0 to 5 mm.

[0013] In an implementable solution, the magnetizing direction of the mover magnet is radial, and the magnetizing directions of the adjusting magnet and the fixed magnet are both axial and the same.

[0014] In an implementable solution, the radial dimensions of the adjusting magnet and the fixed magnet are the same, the axial length of the adjusting magnet is L1, and the axial length of the fixed magnet is L2, wherein L1:L2=0.5-1.

[0015] In an implementable solution, the voice coil motor further includes a guide structure, the guide structure including a guide rail seat and a guide rail assembly, the guide rail seat is mounted on the base and distributed around the mover assembly; the guide rail assembly is placed between the mover bracket and the guide rail seat; the guide rail assembly includes a first guide rail and a second guide rail that slide with each other; the first guide rail is mounted on the mover bracket, and the second guide rail is mounted on the guide rail seat; the relative sliding direction of the first guide rail and the second guide rail is along the axial direction.

[0016] In an implementable solution, there are two guide rail seats, which are symmetrically installed on the base; the mover bracket is located between the two guide rail seats, and each guide rail seat is connected to the mover bracket through two sets of guide rail assemblies.

[0017] In one feasible solution, among the two second guide rails installed on the guide rail seat, one second guide rail is fixedly installed, and the other second guide rail is installed on the guide rail seat in an adjustable manner; wherein, an adjustment member is provided on the guide rail seat at the installation position of the adjustable second guide rail, and the distance between the current second guide rail and the other second guide rail is adjusted by the adjustment member.

[0018] In one feasible solution, a limit groove with a predetermined length in the axial direction is provided on the guide rail seat, and a limit piece is installed on the side of the mover bracket facing the guide rail seat; the limit piece extends into the limit groove away from one end of the mover bracket, and the limit piece moves with the mover bracket and is limited within the length range of the limit groove.

[0019] In an implementable solution, the voice coil motor also includes a displacement monitoring component, which includes a grating scale and a grating reader that match each other. The grating scale is installed on the side of the mover bracket, and the grating reader is installed on the base and facing the grating scale.

[0020] In one feasible solution, the axial length of the mover magnet is H1, and the axial length of the coil is H2; wherein, the axial movement stroke of the mover assembly relative to the stator assembly is L; when the coil is not energized, the length difference between the axial ends of the mover magnet and the axial ends of the coil is M, and satisfies

[0021] In an implementable solution, the bottom end of the adjustment bracket is provided with an external thread, the base is provided with a through hole, the bottom end of the adjustment bracket passes through the through hole of the base and forms a threaded fit with an adjustment nut.

[0022] Compared to existing technologies, the present invention offers at least the following advantages: The voice coil motor employs a purely mechanical adjustment method to control the axial position of the adjustment bracket, enabling the adjustment of the axial position of the adjustment magnet within a defined axial length range, thereby adjusting the magnitude of the voice coil motor's magnetic buoyancy. This design provides the voice coil motor with a relatively wide range of gravity compensation, enabling greater adaptability to loads of varying weights.

[0023] When driving a heavier load for axial movement, traditional magnetic levitation voice coil motors often need to rely solely on increasing the coil current to increase the Lorentz force to achieve suspension compensation. The voice coil motor of this application breaks through this limitation. It enhances the magnetic levitation force by adjusting the axial position of the magnetic steel, thereby sharing the additional demand for the Lorentz force to be used for suspension. In this way, the Lorentz force can be more focused on driving the axial movement of the load, thereby helping to improve the accuracy of axial movement. This optimized design enables the coil current to be stabilized at a relatively reasonable level, avoiding the problem of motor heating caused by continuous excessive current, while ensuring that the response speed of the system is maintained at a high level.

[0024] Furthermore, adjusting the axial position of the magnet to alter the magnetic buoyancy does not alter the overall dimensions of the voice coil motor. This design significantly broadens the application scenarios of voice coil motors without increasing the device size or changing the original structural layout, enabling them to more flexibly address diverse industrial needs and space constraints, demonstrating greater practicality and broad applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a first-perspective stereoscopic view of a voice coil motor shown in an embodiment of the present application.

[0027] Figure 2 This is a stereoscopic image from a second perspective of a voice coil motor shown in an embodiment of the present application.

[0028] Figure 3 This is a top view of a voice coil motor shown in an embodiment of the present application.

[0029] Figure 4 This is a structural diagram of a module cover of a voice coil motor mover assembly shown in an embodiment of the present application.

[0030] Figure 5 This is a schematic diagram of the internal structure of a voice coil motor shown in Example 1 of the present application.

[0031] Figure 6 for Figure 5 Magnetic field diagram of a voice coil motor.

[0032] Figure 7a for Figure 5A graph showing the relationship between the adjustable magnetic buoyancy of the voice coil motor and the displacement of the rotor assembly.

[0033] Figure 7b for Figure 5 A graph showing the relationship between the adjustable magnet position and magnetic buoyancy of a mid-range voice coil motor.

[0034] Figure 8 This is a schematic diagram of the internal structure of a voice coil motor shown in Example 2 of the present application.

[0035] Figure 9 、 Figure 10 and Figure 11 for Figure 8 Schematic diagram of the magnetizing direction of each magnet in the voice coil motor.

[0036] Figure 12 for Figure 8 Magnetic field diagram of a voice coil motor.

[0037] Figure 13a for Figure 8 A graph showing the relationship between the adjustable magnetic buoyancy of the voice coil motor and the displacement of the rotor assembly.

[0038] Figure 13b for Figure 8 A graph showing the relationship between the adjustable magnet position and magnetic buoyancy of a mid-range voice coil motor.

[0039] Figure 14 for Figure 8 Dimensional drawing of the adjustable and fixed magnets of the voice coil motor.

[0040] Figure 15 for Figure 8 Relationship curve between the different spacings between the adjustable magnet and the fixed magnet of the voice coil motor and the magnetic buoyancy fluctuation.

[0041] Figure 16 for Figure 8 Relationship curve between the different axial length ratios of the adjustable magnet and the fixed magnet of the voice coil motor and the magnetic buoyancy fluctuation.

[0042] Figure 17 This is a dimensioned diagram of the coil and the rotor magnet of the voice coil motor shown in an embodiment of the present application.

[0043] Figure 18 This is a curve showing the relationship between the axial length difference between the coil and the rotor magnet and the magnetic buoyancy fluctuation of the voice coil motor of this application.

[0044] In the figure: 1. Base; 2. Coil assembly; 21. Coil bracket; 22. Coil; 3. Adjustment assembly; 31. Adjustment bracket; 32. Adjustment magnet; 33. Fixed magnet; 34. Adjustment nut; 4. Mover assembly; 41. Mover bracket; 411. Inner bracket; 412. Module cover; 413. Limiting piece; 42. Mover magnet; 5. Guide structure; 51. Guide rail seat; 511. Limiting groove; 52. Guide rail assembly; 521. First guide rail; 522. Second guide rail; 53. Adjustment piece; 54. Fixing bolt; 6. Displacement monitoring assembly; 61. Grating scale; 62. Grating reader. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0047] like Figure 5 and Figure 8 As shown, the present application provides a voice coil motor, comprising a base 1, a stator assembly and a mover assembly 4. The moving direction of the mover assembly 4 is axial, and the direction perpendicular to the axial direction is radial.

[0048] Among them, the stator assembly includes a coil assembly 2 and an adjustment assembly 3, and the coil assembly 2 includes a coil bracket 21 and a coil 22. The coil bracket 21 is cylindrical and its bottom is installed on the base 1, and the coil 22 is wound on the outer wall of the coil bracket 21. The adjustment assembly 3 is placed inside the coil bracket 21, and at least includes a cylindrical adjustment bracket 31 and an adjustment magnet 32 ​​mounted on the adjustment bracket 31; wherein the adjustment bracket 31 is connected to the base 1 in a manner that can adjust its position axially. The mover assembly 4 includes a mover bracket 41 and a mover magnet 42 mounted on the mover bracket 41. The mover magnet 42 is cylindrical and is mounted on the outside of the stator assembly.

[0049] In the voice coil motor of the present application, the axial position of the adjustment bracket 31 is adjusted purely mechanically to change the position of the adjustment magnet 32 ​​in the Z direction within a certain range, thereby regulating the magnitude of the magnetic buoyancy of the voice coil motor. This enables the voice coil motor of the present application to effectively expand its compensable gravity range. When driving a heavier load for axial movement, there is no need to simply rely on increasing the current of the coil 22 to increase the Lorentz force to achieve suspension compensation. Instead, the magnetic buoyancy can be enhanced by adjusting the axial position difference between the adjustment magnet 32 ​​and the mover magnet 42, thereby sharing the pressure of the Lorentz force, so that the Lorentz force can be more focused on driving the axial movement of the load, which helps to improve the accuracy of the axial movement. In addition, the current of the coil 22 can be maintained at a relatively reasonable level, which helps to reduce motor heating while ensuring that the system response speed can still be maintained at a high level.

[0050] In addition, the method of changing the magnetic buoyancy by adjusting the axial position of the adjustment bracket 31 does not change the overall size of the voice coil motor. Therefore, this design significantly broadens the application scenarios of the voice coil motor without increasing the volume of the device.

[0051] In order to explain the structure and working principle of the voice coil motor in more detail, the present application provides the following embodiments. It should be noted that the technical features and technical solutions in the following embodiments can be used in combination with each other without conflict.

[0052] Example 1

[0053] like Figure 5 As shown, this embodiment provides a voice coil motor, including a base 1, a stator assembly, and a mover assembly 4. The direction of movement of the mover assembly 4 is axial, and the direction perpendicular to the axial direction is radial. The axial direction is the Z direction indicated in the figure.

[0054] The stator assembly includes a coil assembly 2 and an adjustment assembly 3. The coil assembly 2 includes a coil support 21 and a coil 22. The coil support 21 is cylindrical and its bottom is mounted on the base 1. The coil 22 is wound around the outer wall of the coil support 21. The adjustment assembly 3 is placed inside the coil support 21 and includes a cylindrical adjustment support 31 and an adjustment magnet 32 ​​mounted on the adjustment support 31. The adjustment support 31 is connected to the base 1 in a manner that allows adjustment in the Z direction. For example, the bottom end of the adjustment support 31 can be provided with an external thread, and the base 1 is provided with a through hole. The bottom end of the adjustment support 31 passes through the through hole of the base 1 and forms a threaded engagement with an adjustment nut 34. By turning the adjustment nut 34, the position of the adjustment support 31 in the Z direction can be adjusted. The mover assembly 4 includes a mover support 41 and a mover magnet 42 mounted on the mover support 41. The mover magnet 42 is cylindrical and mounted on the outside of the stator assembly.

[0055] And, as Figure 5 and Figure 6 As shown, the magnetization direction of the regulating magnetic steel 32 is along the axial direction, and the magnetization direction of the mover magnetic steel 42 is along the radial direction. The regulating magnetic steel 32 and the mover magnetic steel 42 can be rare earth permanent magnets with high magnetic energy product, such as neodymium iron boron permanent magnets, samarium cobalt permanent magnets, etc.

[0056] Figure 7b A curve diagram showing the relationship between the change in the Z-direction position of the adjusting magnet 32 ​​and the magnitude of the magnetic buoyancy force is shown. From this, it can be seen that when the coil 22 is not energized, the magnitude of the magnetic buoyancy force of the voice coil motor can be changed by adjusting the position of the adjusting magnet 32 ​​along the Z-direction, thereby adapting to different loads.

[0057] Figure 7a A graph showing the relationship between the adjustable Z-direction displacement of the mover magnet 42 and the magnetic buoyancy force of the voice coil motor of this embodiment is shown. The different curves in the graph represent the variation in magnetic buoyancy force output with Z-direction displacement after the adjustable magnet 32 ​​is adjusted to different Z-direction positions. Overall, the fluctuation in magnetic buoyancy force after adjustment of the adjustable magnet 32 ​​is relatively small. With changes in the Z-direction displacement of the motor, the overall fluctuation in magnetic buoyancy force is generally controllable within ±2%, and within certain magnetic buoyancy force ranges, the fluctuation is controllable within ±1%.

[0058] It should be noted that the mover magnet 42 will also produce changes in magnetic buoyancy during movement. However, since the displacement amplitude of the mover magnet 42 along the Z direction is small, and the magnetic levitation change is smaller as it approaches the zero position, the corresponding overall magnetic buoyancy change is also relatively small. In contrast, the adjustable stroke range of the regulating magnet 32 ​​along the Z direction is larger. From the perspective of the relationship between the overall displacement of the regulating magnet 32 ​​and the change in magnetic buoyancy, it is closer to a straight line with a constant slope. It is precisely because of the relatively significant Z-direction displacement capability of the regulating magnet 32 ​​that the regulating magnet 32 ​​can effectively change the overall magnetic buoyancy of the system.

[0059] In summary, the voice coil motor of this embodiment uses purely mechanical adjustment to control the Z-axis position of the adjustment bracket 31. This adjusts the relative position between the adjustment magnet 32 ​​and the mover magnet 42 within a limited Z-axis length range, thereby adjusting the magnetic buoyancy of the voice coil motor. This design gives the voice coil motor a relatively large gravity compensation range, making it more adaptable to loads of varying weights.

[0060] When driving a heavier load to move in the Z direction, a traditional magnetic levitation voice coil motor often needs to rely solely on increasing the coil current to increase the Lorentz force to achieve suspension compensation. The voice coil motor of this embodiment breaks through this limitation. By adjusting the position difference between the regulating magnet 32 ​​and the mover magnet 42 along the Z direction, the magnetic levitation force is enhanced, thereby sharing the additional need for the Lorentz force to be used for suspension. In this way, the Lorentz force can be more focused on driving the Z-direction movement of the load, thereby helping to improve the accuracy of the Z-direction movement. This optimized design allows the current of the coil 22 to be stabilized at a relatively reasonable level, avoiding the problem of motor heating caused by continuous excessive current, while ensuring that the response speed of the system is maintained at a high level.

[0061] It's particularly noteworthy that adjusting the magnetic buoyancy force by adjusting the Z-axis position of the adjustment bracket 31 does not alter the overall dimensions of the voice coil motor. This design significantly broadens the application scenarios of voice coil motors without increasing the device's size or changing the original structural layout, enabling them to more flexibly address diverse industrial needs and space constraints, demonstrating greater practicality and broad applicability.

[0062] In summary, the voice coil motor of this embodiment can adjust the magnetic buoyancy by changing the position of the adjusting magnet 32 ​​along the Z direction, so that the voice coil motor can adapt to the suspension support of loads with different gravity.

[0063] In this embodiment, Figures 1 to 3 As shown, the voice coil motor may further include a guide structure 5, which includes a guide rail seat 51 and a guide rail assembly 52. ​​The guide rail seat 51 is mounted on the base 1 and distributed around the mover assembly 4. The guide rail assembly 52 is placed between the mover bracket 41 and the guide rail seat 51. The guide rail assembly 52 includes a first guide rail 521 and a second guide rail 522 that slide with each other. The first guide rail 521 is mounted on the mover bracket 41, and the second guide rail 522 is mounted on the guide rail seat 51. The relative sliding direction of the first guide rail 521 and the second guide rail 522 is along the Z direction. The setting of the guide structure 5 can limit the movement direction of the mover bracket 41 along the Z direction, which helps to reduce micro-movement in directions other than the Z direction and improve positioning accuracy and Z-direction motion accuracy.

[0064] In this embodiment, if Figure 2 and Figure 3 As shown, there are preferably two guide rail seats 51 , which are symmetrically installed on the base 1 , the mover bracket 41 is located between the two guide rail seats 51 , and each guide rail seat 51 is connected to the mover bracket 41 through two sets of guide rail assemblies 52 .

[0065] In this embodiment, if Figure 2 and Figure 3As shown, preferably, the spacing between the two second guide rails 522 mounted on each guide rail seat 51 is configured to be adjustable. Specifically, of the two second guide rails 522 mounted on the guide rail seat 51, one second guide rail 522 is fixedly mounted, while the other second guide rail 522 is adjustable. An adjustment member 53 is provided on the guide rail seat 51 at the mounting position of the adjustable second guide rail 522, which is used to adjust the spacing between the current second guide rail 522 and the other second guide rail 522. The two guide rail seats 51 are respectively a first guide rail seat and a second guide rail seat. The adjustable second guide rail 522 mounted on the first guide rail seat is located on the same side as the adjustable second guide rail 522 mounted on the second guide rail seat. The adjustment member 53 can be a jackscrew structure. After the adjustment member 53 adjusts the position of the corresponding second guide rail 522, the second guide rail 522 is locked and fixed in place by a fixing bolt 54. This embodiment realizes the adjustment of the clearance between the mover assembly 4 and the guide rail seat 51 by setting the distance between the two second guide rails 522 installed on each guide rail seat 51 to be adjustable, thereby adjusting the smoothness of the Z-direction movement, preventing structural jamming, and reducing non-Z-direction micro-movements, thereby improving positioning and movement accuracy.

[0066] In this embodiment, if Figure 4 and Figure 5 As shown, the mover support 41 can include an inner support 411 and a module cover 412. The module cover 412 can be a shell-like structure with one end open. The inner support 411 is mounted on the inner side of the module cover 412, and the mover magnet 42 is mounted on the inner support 411. The top of the module cover 412 is used to connect to the load, and the side of the module cover 412 is used to connect to the guide rail seat 51 through the guide rail assembly 52.

[0067] In this embodiment, if Figure 2 As shown, the guide rail seat 51 can be provided with a limiting groove 511 having a predetermined length along the Z direction, and a limiting member 413 is installed on the side of the mover bracket 41 facing the guide rail seat 51. The limiting member 413 extends into the limiting groove 511 at one end away from the mover bracket 41. The limiting member 413 moves with the mover bracket 41 and is restricted within the length range of the limiting groove 511. For example, a threaded hole can be provided on the side of the module cover 412 facing the limiting groove 511. The limiting member 413 can be a limiting bolt, which is assembled in the threaded hole and extends into the limiting groove 511. Through the cooperation between the limiting groove 511 and the limiting member 413, the mechanical movement of the mover assembly 4 can be limited.

[0068] In this embodiment, if Figure 1 and Figure 2As shown, the voice coil motor also includes a displacement monitoring assembly 6, which comprises a matching grating scale 61 and a grating reader 62. The grating scale 61 is mounted on the side of the mover bracket 41, and the grating reader 62 is mounted on the base 1 and faces the grating scale 61. The control device reads the signal from the grating reader 62 to detect and locate the Z-direction displacement of the voice coil motor's mover assembly 4. Based on this positioning information, the current in the coil 22 is then controlled to ensure that the mover assembly 4 moves to the predetermined position in the Z-direction. This detection feedback improves the Z-direction motion and positioning accuracy.

[0069] In this embodiment, if Figure 17 As shown, the axial length of the mover magnet 42 is H1, and the axial length of the coil 22 is H2. The axial movement stroke of the mover assembly 4 relative to the stator assembly is L. When the coil 22 is not energized, the length difference between the axial ends of the mover magnet 42 and the axial ends of the coil 22 is M, and it satisfies Wherein, L is the axial movement stroke of the mover assembly 4 relative to the stator assembly.

[0070] Among them, simulation verification is carried out, and the results are as follows Figure 18 As shown, assuming that the axial movement stroke of the movable subassembly 4 relative to the stator assembly is L=2mm, that is, the stroke of the movable subassembly 4 of the voice coil motor along the Z direction is -2mm to 2mm, through Figure 18 The simulation curve shows that when M is less than -2mm or M is greater than 2mm, the magnetic buoyancy fluctuation is small. Under these conditions, the fluctuation of magnetic buoyancy is relatively small.

[0071] In this embodiment, the adjustment magnet 32 ​​may include only one integral magnet, or may be formed by a plurality of magnets tightly spliced ​​together along the axial direction, or may include a plurality of magnets fixed to the adjustment bracket 31 at intervals along the axial direction.

[0072] Example 2

[0073] like Figure 8 As shown, this embodiment also provides a voice coil motor. The difference from the first embodiment is that the adjustment component of this embodiment further includes a fixed magnet 33.

[0074] Specifically, the fixed magnet 33 is installed on the inner bottom of the coil bracket 21, and is sleeved on the outside of the adjustment bracket 31 and is located below the adjustment magnet 32, that is, the fixed magnet 33 is fixed between the adjustment magnet 32 ​​and the bottom of the coil bracket 21; wherein, the fixed magnet 33 and the adjustment bracket 31 maintain relative sliding.

[0075] In this embodiment, if Figure 9 、 Figure 10 and Figure 11As shown, the magnetization direction of the movable magnet 42 is radial, and can be radially from the inside to the outside, or radially from the outside to the inside. The magnetization direction of the adjustment magnet 32 ​​and the magnetization direction of the fixed magnet 33 are both axial and the same, and can be in the positive axial direction or the negative axial direction. Figure 12 A magnetic field line diagram of the voice coil motor of this embodiment is shown, wherein the magnetizing directions of the adjustment magnet 32 ​​and the fixed magnet 33 are both along the axial positive direction, and the magnetizing direction of the mover magnet 42 is from inside to outside in the radial direction.

[0076] Figure 13b A graph shows the relationship between the Z-axis position change of the adjustable magnet 32 ​​and the magnitude of the magnetic buoyancy force, with the horizontal axis representing the distance between the adjustable magnet 32 ​​and the fixed magnet 33. This shows that when the coil 22 is not energized, the magnetic buoyancy force of the voice coil motor can be varied by adjusting the distance between the adjustable magnet 32 ​​and the fixed magnet 33, thereby adapting to different loads.

[0077] Figure 13a A graph showing the relationship between the adjustable displacement of the rotor magnet 42 in the Z-direction and the magnetic levitation force of the voice coil motor of this embodiment is shown. The different curves in the graph represent how the magnetic levitation force changes with the Z-direction displacement output for different spacings between the adjustable magnet 32 ​​and the fixed magnet 33. Overall, while the magnetic levitation force can be adjusted after adjusting the spacing between the adjustable magnet 32 ​​and the fixed magnet 33, the overall fluctuation is relatively small. As can be seen from the graph, the overall fluctuation of the magnetic levitation force can be generally controlled within ±2% with changes in the motor's Z-direction displacement, and within certain magnetic levitation force ranges, the fluctuation can be controlled within ±1%.

[0078] In summary, the voice coil motor of this embodiment uses purely mechanical adjustment to control the Z-axis position of the adjustment bracket 31. This adjustment modifies the spacing between the adjustment magnet 32 ​​and the fixed magnet 33 within a defined Z-axis length range, thereby adjusting the magnetic buoyancy of the voice coil motor. This design also gives the voice coil motor a relatively wide range of gravity compensation, making it more adaptable to loads of varying weights.

[0079] When driving a heavier load for Z-direction motion, the voice coil motor of this embodiment enhances the magnetic buoyancy by adjusting the distance between the regulating magnet 32 ​​and the fixed magnet 33, thereby alleviating the need for the Lorentz force to be used for suspension. In this way, the Lorentz force can be more focused on driving the load's Z-direction motion, thereby helping to improve the accuracy of Z-direction motion. This optimized design allows the current in the coil 22 to be stabilized at a relatively reasonable level, avoiding motor heating problems caused by continuous excessive current, while ensuring that the system's response speed is maintained at a high level.

[0080] Similarly, adjusting the Z-axis position of the adjustment bracket 31, thereby altering the spacing between the adjustment magnet 32 ​​and the fixed magnet 33, changes the magnitude of the magnetic buoyancy without changing the overall dimensions of the voice coil motor. This design significantly broadens the application scenarios of voice coil motors without increasing the device's size or changing the original structural layout, enabling them to more flexibly address diverse industrial needs and space constraints, demonstrating greater practicality and broad applicability.

[0081] As can be seen from the above, the voice coil motor of this embodiment also adjusts the magnetic levitation force by changing the position of the adjustment magnet 32 ​​along the Z direction, thereby enabling the voice coil motor to adapt to the levitation support of loads with different gravitational forces. However, unlike the first embodiment, this embodiment adds a fixed magnet 33 below the adjustment magnet 32. Therefore, when adjusting the Z position of the adjustment magnet 32, the spacing between the adjustment magnet 32 ​​and the fixed magnet 33 also changes, thereby achieving more precise adjustment of the magnetic levitation force.

[0082] In this embodiment, if Figure 14 As shown, the sliding range between the adjustment magnetic steel 32 and the fixed magnetic steel 33 is H, wherein the range of H is preferably set to 0 to 5 mm.

[0083] Carry out simulation verification, the simulation results are as follows Figure 15 As shown, combined with Figure 13b As can be seen from the figure, when the sliding range H between the adjustment magnetic steel 32 and the fixed magnetic steel 33 is within the range of 0 to 5 mm, the fluctuation of the magnetic buoyancy can be controlled within a smaller range while achieving the adjustment of the magnetic buoyancy. Under the premise that the adjusted magnetic buoyancy meets the requirements, the range of H can be preferably set to 0 to 4 mm, 0 to 3 mm, 1 to 3 mm, 1 to 2 mm, etc. In this embodiment, if Figure 14 As shown, the radial dimensions of the adjusting magnetic steel 32 and the fixed magnetic steel 33 are preferably set to be the same, the axial length of the adjusting magnetic steel 32 is L1, and the axial length of the fixed magnetic steel 33 is L2, wherein L1:L2 is preferably 0.5 to 1. Simulation verification is performed, and the simulation results are as follows Figure 16 As shown, the magnetic buoyancy force fluctuates less in the range of L1:L2 = 0.5 to 1. More preferably, L1:L2 = 0.75 to 1, or L1:L2 = 0.8 to 1, or L1:L2 = 0.85 to 1, or L1:L2 = 0.9 to 1.

[0084] The foregoing description is merely a partial list of preferred embodiments of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A voice coil motor, characterized in that: It comprises a base (1), a stator assembly and a mover assembly (4); the moving direction of the mover assembly (4) is defined as an axial direction, and the direction perpendicular to the axial direction is defined as a radial direction; The stator assembly includes a coil assembly (2) and an adjustment assembly (3); The coil assembly (2) comprises a coil support (21) and a coil (22); the coil support (21) is cylindrical and its bottom is mounted on the base (1); and the coil (22) is wound around the outer wall of the coil support (21); The adjustment assembly (3) is placed inside the coil support (21), and comprises a cylindrical adjustment support (31) and an adjustment magnet (32) sleeved and mounted on the adjustment support (31); wherein the adjustment support (31) is connected to the base (1) in a manner that allows the position to be adjusted along the axial direction; The mover assembly (4) comprises a mover bracket (41) and a mover magnet (42) mounted on the mover bracket (41); the mover magnet (42) is cylindrical and sleeved on the outside of the stator assembly.

2. The voice coil motor according to claim 1, wherein: The magnetizing direction of the regulating magnetic steel (32) is along the axial direction, and the magnetizing direction of the mover magnetic steel (42) is along the radial direction.

3. The voice coil motor according to claim 1, wherein: The adjustment component further comprises a fixed magnetic steel (33), which is fixedly mounted on the inner bottom of the coil bracket (21), and is sleeved on the outer side of the adjustment bracket (31) and is located below the adjustment magnetic steel (32); wherein the fixed magnetic steel (33) and the adjustment bracket (31) maintain relative sliding.

4. The voice coil motor according to claim 3, wherein: The sliding range between the regulating magnetic steel (32) and the fixed magnetic steel (33) is H, wherein the range of H is 0 to 5 mm.

5. The voice coil motor according to claim 3, wherein: The magnetizing direction of the movable magnetic steel (42) is radial, and the magnetizing direction of the regulating magnetic steel (32) and the magnetizing direction of the fixed magnetic steel (33) are both axial and identical.

6. The voice coil motor according to claim 3, wherein: The radial dimensions of the regulating magnetic steel (32) and the fixed magnetic steel (33) are the same. The axial length of the regulating magnetic steel (32) is L1, and the axial length of the fixed magnetic steel (33) is L2, wherein L1:L2=0.5-1.

7. The voice coil motor according to claim 1, wherein: The voice coil motor further comprises a guide structure (5), wherein the guide structure (5) comprises a guide rail seat (51) and a guide rail assembly (52), wherein the guide rail seat (51) is mounted on the base (1) and distributed around the mover assembly (4); The guide rail assembly (52) is placed between the mover bracket (41) and the guide rail seat (51); The guide rail assembly (52) comprises a first guide rail (521) and a second guide rail (522) that are slidably engaged with each other; The first guide rail (521) is installed on the mover bracket (41), and the second guide rail (522) is installed on the guide rail seat (51); The relative sliding direction of the first guide rail (521) and the second guide rail (522) is along the axial direction.

8. The voice coil motor according to claim 7, wherein: There are two guide rail seats (51) which are symmetrically mounted on the base (1); The mover bracket (41) is located between the two guide rail seats (51), and each guide rail seat (51) is connected to the mover bracket (41) via two groups of guide rail assemblies (52).

9. The voice coil motor according to claim 8, wherein: Of the two second guide rails (522) installed on the guide rail seat (51), one of the second guide rails (522) is fixedly installed, and the other second guide rail (522) is installed on the guide rail seat (51) in a positionally adjustable manner; Wherein, an adjusting member (53) is provided on the guide rail seat (51) at the installation position of the second guide rail (522) whose position can be adjusted, and the distance between the current second guide rail (522) and another second guide rail (522) is adjusted by the adjusting member (53).

10. The voice coil motor according to claim 7, wherein: The guide rail seat (51) is provided with a limiting groove (511) having a predetermined length in the axial direction, and a limiting member (413) is installed on one side of the mover bracket (41) facing the guide rail seat (51); One end of the limiting member (413) away from the movable support (41) extends into the limiting groove (511); the limiting member (413) moves along with the movable support (41) and is limited within the length range of the limiting groove (511).

11. The voice coil motor according to claim 1, wherein: The voice coil motor further includes a displacement monitoring assembly (6), which includes a grating ruler (61) and a grating reader (62) that match each other, wherein the grating ruler (61) is mounted on the side of the mover bracket (41), and the grating reader (62) is mounted on the base (1) and faces the grating ruler (61).

12. The voice coil motor according to claim 1 or 3, characterized in that: The axial length of the movable magnetic steel (42) is H1, and the axial length of the coil (22) is H2; The axial movement stroke of the movable component (4) relative to the stator component is L; when the coil (22) is not energized, the length difference between the axial ends of the movable magnetic steel (42) and the axial ends of the coil (22) is M, and satisfies 13. The voice coil motor according to any one of claims 1 to 11, characterized in that: The bottom end of the adjustment bracket (31) is provided with an external thread, and the base (1) is provided with a through hole. The bottom end of the adjustment bracket (31) passes through the through hole of the base (1) and forms a threaded fit with an adjustment nut (34).

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