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EP-4742698-A1 - DESIGN METHOD AND APPARATUS FOR NONLINEAR TERM-CANCELLED MOVING MAGNET VIBRATOR, AND USE

EP4742698A1EP 4742698 A1EP4742698 A1EP 4742698A1EP-4742698-A1

Abstract

Provided is a moving-magnet vibrator with nonlinear term cancellation. The moving-magnet vibrator with nonlinear term cancellation includes a moving-magnet vibrator body, which includes an outer cylinder, a vibration transmission plate, a stator assembly and a movable assembly. The movable assembly is configured to be simultaneously subjected to paired electromagnetic forces of push and pull, thereby presenting push-pull structural characteristics.

Inventors

  • HU, ZHONGJI
  • HU, Siqin

Assignees

  • Imove Intelligent Technologies (Dongguan) Co. Ltd.

Dates

Publication Date
20260513
Application Date
20240320

Claims (20)

  1. A moving-magnet vibrator with nonlinear term cancellation, comprising: a moving-magnet vibrator body; wherein the moving-magnet vibrator body comprises an outer cylinder, a vibration transmission plate, a stator assembly and a movable assembly, the stator assembly comprises a coil combination structure, and the movable assembly comprises a magnet combination structure; the stator assembly is fixed inside the outer cylinder, the vibration transmission plate is fixed on the outer cylinder, and the movable assembly is fixedly connected to the vibration transmission plate through at least one contact point; the movable assembly moves while the stator assembly remains stationary, and the movable assembly is referred to as a moving component; and the movable assembly is configured to be simultaneously subjected to paired electromagnetic forces of push and pull, thereby presenting push-pull structural characteristics.
  2. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 1, wherein in the moving-magnet vibrator body, 2N magnetic domains D 1,i and D 2,i are designed as N symmetrical pairs, where N=1, 2, 3, ..., 100, and i=1, 2, 3, ....
  3. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 2, wherein the magnet combination structure comprise a permanent magnet, the coil combination structure comprises a coil, and the number of the permanent magnet in the magnet combination structure and the number of the coil in the coil combination structure are limited by N magnet >N coil or N magnet < N coil , where N magnet represents the number of the permanent magnet, N coil represents the number of the coil, N magnet =1, 2, 3, ...,100, and N coil =1, 2, 3, ..., 100.
  4. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 3, wherein in the push-pull structural characteristics, linear terms of the electromagnetic force acting on the movable assembly are superimposed to be increased, and nonlinear terms of the electromagnetic force acting on the movable assembly are partially or completely canceled to be decreased.
  5. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 2, wherein closed main magnetic flux lines of a coil in the coil combination structure and closed main magnetic flux lines of a permanent magnet in the magnet combination structure each pass through magnetic domains D 1,i and D 2,i ; the magnetic domain is a spatial region filled with electromagnetic energy, the magnetic domain is composed of air or a medium with a relative magnetic permeability less than 1000, and comprises a region where a magnet material is located; in the magnetic domain D 1,i , a direction of magnetic flux lines of the coil is the same as a direction of magnetic flux lines of the permanent magnet, and in the magnetic domain D 2,i , the direction of the magnetic flux lines of the coil is opposite to the direction of the magnetic flux lines of the permanent magnet; alternatively, in the magnetic domain D 1,i , the direction of the magnetic flux lines of the coil is opposite to the direction of the magnetic flux lines of the permanent magnet, and in the magnetic domain D 2,i , the direction of the magnetic flux lines of the coil is the same as the direction of the magnetic flux lines of the permanent magnet.
  6. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 5, wherein the moving component is subjected to 2N forces, where N=1, 2, 3, ..., 100; each component force comprises two parts: one part is a linear term of an excitation current i, and another part is a nonlinear term of the excitation current i: F moving − magnet , n i = F moving − magnet , n , linear i + F moving − magnet , n , nonlinear i , where n = 1, 2, 3, ..., 2N - 1, 2N; a resultant force on the moving component comprises two parts: one part is a linear term of the excitation current i, and another part is a nonlinear term of the excitation current i: F moving − magnet , resultant force i = F moving − magnet , resultant force , linear i + F moving − magnet , resultant force , nonlinear i ; where: F moving − magnet , resultant force i = ∑ n = 1 2 N F moving − magnet , n i = ∑ n = 1 N F moving − magnet , n , 1 i + F moving − magnet , n , 2 i ; F moving − magnet , resultant force , linear i = ∑ n = 1 2 N F moving − magnet , n , linear i = ∑ n = 1 N F moving − magnet , linear , 1 i + F moving − magnet , linear , 2 i ; and F moving − magnet , resultant force , nonlinear i = ∑ n = 1 2 N F moving − magnet , n , nonlinear i = ∑ n = 1 N F moving − magnet , nonlinear , 1 i + F moving − magnet , nonlinear , 2 i ; the nonlinear terms in each component force are partially or completely canceled, and in a final total resultant force Σ i (F 1,i + F 2,i ), the nonlinear terms of the total resultant force relative to the excitation current are partially or completely canceled, and the linear terms are superimposed to be increased, thereby obtaining the moving-magnet vibrator with nonlinear term cancellation.
  7. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 1, wherein the coil combination structure comprises a coil and a first magnetic conductor, and the magnet combination structure comprises a permanent magnet and a second magnetic conductor.
  8. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 1, wherein the magnet combination structure comprises a magnet component and a second magnetic conductor; the magnet component is a single magnet or an assembly of a plurality of magnets, the assembly of plurality of magnets generating an overall magnetic field equivalent to a magnetic field generated by a certain single magnet, directions of magnetic fields generated by the plurality of magnets of the assembly are the same as a direction of a certain dominant magnetic field; the plurality of magnets are connected through a rigid structural component, or a flexible structural component arranged between the magnets, at edges of the magnets, or around the magnets, or connected through a manner without a structural component, including bonding, welding, embedding, screws, spirals, riveting, bolts, buckles, clamping jaws, brackets, sleeves, or glands.
  9. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 1, wherein the coil combination structure comprises a coil component and a first magnetic conductor, the coil component is a single coil or an assembly of a plurality of coils, the assembly of plurality of coils generating an overall magnetic field equivalent to a magnetic field generated by a certain single coil, directions of magnetic fields generated by the plurality of coils of the assembly are the same as a direction of a magnetic field generated by a certain dominant coil; the plurality of coils are connected through a rigid structural component, or a flexible structural component arranged between the coils, at edges of the coils, or around the coils, or a manner without a structural component, including bonding, welding, embedding, screws, spirals, riveting, bolts, buckles, clamping jaws, brackets, sleeves, or glands.
  10. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 7, wherein the movable assembly and the stator assembly are in concave-convex shapes and arranged in an interleaved engagement manner, and closed main magnetic flux lines of the coil and closed main magnetic flux lines of a permanent magnet alternately pass through the movable assembly and the stator assembly.
  11. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 3, wherein: looking outward from a center, the permanent magnet is located inside and the coil is located outside; N magnet = N coil + 1 × n , where n is a natural number, n = 1, 2, 3...; and when N magnet >1, polarities of two opposite end faces of adjacent permanent magnets are the same; when N coil >1, directions of currents in adjacent coils are opposite, and polarities of electromagnetic fields at adjacent end faces of two adjacent coils are the same.
  12. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 3, wherein: looking outward from a center, the permanent magnet is located inside and the coil is located outside; N magnet = N coil − 1 × n , where n is a natural number, n = 1, 2, 3...; and when N magnet >1, polarities of two opposite end faces of adjacent permanent magnets are the same; when N coil >1, directions of currents in adjacent coils are opposite, and polarities of electromagnetic fields at adjacent end faces of two adjacent coils are the same.
  13. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 3, wherein: looking outward from a center, the coil is located inside and the permanent magnet is located outside; N magnet = N coil + 1 × n , where n is a natural number, n = 1, 2, 3...; and when N magnet >1, polarities of two opposite end faces of adjacent permanent magnets are the same; when N coil >1, directions of currents in adjacent coils are opposite, and polarities of electromagnetic fields at adjacent end faces of two adjacent coils are the same.
  14. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 3, wherein: looking outward from a center, the coil is located inside and the permanent magnet is located outside; N magnet = N coil − 1 × n , where n is a natural number, n = 1, 2, 3...; and when N magnet >1, polarities of two opposite end faces of adjacent permanent magnets are the same; when N coil >1, directions of currents in adjacent coils are opposite, and polarities of electromagnetic fields at adjacent end faces of two adjacent coils are the same.
  15. The moving-magnet vibrator with nonlinear term cancellation as claimed in claim 10, wherein a magnetic conductor is provided at a position of the outer cylinder close to the coil to minimize a magnetic resistance of a magnetic circuit of an electromagnet generated by the coil; the permanent magnet in the magnet assembly is isolated by a magnetic conductor; a yoke iron is used around the coil and the permanent magnet, or for the coil combination structure, a part of the outer cylinder close to the coil is magnetically conductive.
  16. The moving-magnet vibrator device with nonlinear term cancellation as claimed in claim 12, wherein: the coil combination structure further comprises a first magnetic conductor and a first magnetic conductor ring, the magnet combination structure further comprises a second magnetic conductor; the permanent magnet comprises one permanent magnet and the coil comprises two coils; the vibration transmission plate comprises two vibration transmission plates fixed on a top surface and a bottom surface of the outer cylinder respectively; the permanent magnet is fixed in the second magnetic conductor, two ends of the second magnetic conductor are respectively fixed on the two vibration transmission plates; the first magnetic conductor is fixed in middle of an inner side wall of the outer cylinder, and the two coils are respectively fixed on two sides of the first magnetic conductor; the first magnetic conductive ring is fixedly arranged on outer sides of the two coils, and the coils and the first magnetic conductive ring are fixed on the inner side wall of the outer cylinder; the movable assembly and the stator assembly are in concave-convex shapes and arranged in an interleaved engagement manner; closed magnetic flux lines of the coils and closed magnetic flux lines of the permanent magnet alternately pass through the movable assembly and the stator assembly; two magnetic domains D 1,1 and D 2,1 which are designed as a symmetrical pair are provided in the moving-magnet vibrator body, the closed magnetic flux lines of the coil and the closed magnetic flux lines of the permanent magnet each pass through the magnetic domains D 1,1 and D 2,1 ; in the magnetic domain D 1,1 , a direction of magnetic flux lines of one coil is the same as a direction of magnetic flux lines of the permanent magnet, and in the magnetic domain D 2,1 , the direction of the magnetic flux lines of another coil is opposite to the direction of the magnetic flux lines of the permanent magnet.
  17. The moving-magnet vibrator device with nonlinear term cancellation as claimed in claim 13, wherein: the coil combination structure further comprises a first magnetic conductor and a first magnetic conductor ring, the magnet combination structure further comprises a second magnetic conductor and a second magnetic conductive ring, and the permanent magnet comprises two permanent magnets and the coil comprises one coil; the vibration transmission plate comprises one vibration transmission plate fixed on a top surface of the outer cylinder, an end of the first magnetic conductor is fixed on a bottom surface of the outer cylinder, the coil is wound around and fixed on the first magnetic conductor, and the first magnetic conductive ring is fixed at an end of the first magnetic conductor; the moving-magnet vibrator device with nonlinear term cancellation further comprises an L-shaped vibration transmission bracket, a horizontal part of the vibration transmission bracket is parallel to a vibration direction, the second magnetic conductor is fixed on the horizontal part of the vibration transmission bracket, the two permanent magnets are fixedly arranged on two sides of the second magnetic conductor, and the two permanent magnets are fixed on the horizontal part of the vibration transmission bracket; and the movable assembly and the stator assembly are in concave-convex shapes and arranged in an interleaved engagement manner; closed magnetic flux lines of the coil and closed magnetic flux lines of the permanent magnets alternately pass through the movable assembly and the stator assembly; two magnetic domains D 1,1 and D 2,1 which are designed as a symmetrical pair are provided in the moving-magnet vibrator body, the closed magnetic flux lines of the coil and the closed magnetic flux lines of the permanent magnet each pass through the magnetic domains D 1,1 and D 2,1 ; in the magnetic domain D 1,1 , a direction of magnetic flux lines of the coil is opposite to a direction of magnetic flux lines of one permanent magnet, and in the magnetic domain D 2,1 , the direction of the magnetic flux lines of the coil is the same as the direction of the magnetic flux lines of another permanent magnet.
  18. The moving-magnet vibrator device with nonlinear term cancellation as claimed in claim 14, wherein: the magnet combination structure further comprises a second magnetic conductor, the coil combination structure further comprises a first magnetic conductor, a first magnetic conductor ring and a second magnetic conductor ring; the permanent magnet comprises one permanent magnet and the coil comprises two coils; the vibration transmission plate comprises one vibration transmission plate fixed on a top surface of the outer cylinder, an end of the first magnetic conductor is fixed on a bottom surface of the outer cylinder, the two coils are wound around and fixed on the first magnetic conductor, the second magnetic conductive ring is fixed at an end of the first magnetic conductor, and the first magnetic conductive ring is wound around and fixed on a middle part of the first magnetic conductor and located between the two coils; wherein the moving-magnet vibrator device with nonlinear term cancellation further comprises an L-shaped vibration transmission bracket, a horizontal part of the vibration transmission bracket is parallel to a vibration direction, the permanent magnet is fixed in middle of the horizontal part of the vibration transmission bracket, and the second magnetic conductor is located on two sides of the permanent magnet and fixed on the horizontal part of the vibration transmission bracket; and the movable assembly and the stator assembly are in concave-convex shapes and arranged in an interleaved engagement manner; closed magnetic flux lines of the coils and closed magnetic flux lines of the permanent magnet alternately pass through the movable assembly and the stator assembly; four magnetic domains D 1,1 , D 2,1 , D 1,2 and D 2,2 which are designed as two symmetrical pairs are provided in the moving-magnet vibrator body, where D 1,1 is symmetric to D 2,1 , and D 1,2 is symmetric to D 2,2 ; the closed magnetic flux lines of the coil and the closed magnetic flux lines of the permanent magnet each pass through the magnetic domains D 1,1 , D 2,1 , D 1,2 and D 2,2 ; in the magnetic domain D 1,1 , a direction of magnetic flux lines of one coil is opposite to a direction of magnetic flux lines of the permanent magnet; and in the magnetic domain D 2,1 , the direction of the magnetic flux lines of another coil is the same as the direction of the magnetic flux lines of the permanent magnet.
  19. The moving-magnet vibrator device with nonlinear term cancellation as claimed in claim 12, wherein: the magnet combination structure further comprises a second magnetic conductor, and the coil combination structure further comprises a first magnetic conductor and a first magnetic conductor ring; the permanent magnet comprises two permanent magnets; the coil comprises three coils; the vibration transmission plate comprises two vibration transmission plates respectively fixed on a top surface and a bottom surface of the outer cylinder; the two permanent magnets are fixed on two sides of the second magnetic conductor, the two permanent magnets are respectively fixed on magnetic conductive sleeves, and the magnetic conductive sleeves are respectively fixed on the two vibration transmission plates; the three coils are sequentially fixed on an inner side wall of the outer cylinder, the first magnetic conductor is fixedly arranged between adjacent coils, the first magnetic conductive ring is fixedly arranged on an outer side of the outermost coils, and both the first magnetic conductor and the first magnetic conductive ring are fixed on the inner side wall of the outer cylinder; and the movable assembly and the stator assembly are in concave-convex shapes and arranged in an interleaved engagement manner; closed magnetic flux lines of the coils and closed magnetic flux lines of the permanent magnets alternately pass through the movable assembly and the stator assembly; six magnetic domains D 1,1 , D 2,1 , D 1,2 , D 2,2 , D 1,3 , and D 2,3 which are designed as three symmetrical pairs are provided in the moving-magnet vibrator body, where D 1,1 is symmetric to D 2,1 , D 1,2 is symmetric to D 2,2 , and D 1,3 is symmetric to D 2,3 ; the closed magnetic flux lines of the coils and the closed magnetic flux lines of the permanent magnets each pass through the magnetic domains D 1,1 , D 2,1 , D 1,2 , D 2,2 , D 1,3 , and D 2,3 ; in the magnetic domain D 1,1 , a direction of magnetic flux lines of one coil is opposite to a direction of magnetic flux lines of one permanent magnet; in the magnetic domain D 2,1 , the direction of the magnetic flux lines of the one coil is the same as the direction of the magnetic flux lines of another permanent magnet; in the magnetic domain D 1,2 , the direction of the magnetic flux lines of another coil is the same as the direction of the magnetic flux lines of the one permanent magnet; and in the magnetic domain D 2,2 , the direction of the magnetic flux lines of a further coil is opposite to the direction of the magnetic flux lines of the another permanent magnet.
  20. The moving-magnet vibrator device with nonlinear term cancellation as claimed in claim 1 is configured to be applied to a bone conduction headphone, bone conduction glasses, a wired headphone, a wireless headphone, AR glasses, VR glasses, a smart watch, a smart bracelet, a head-mounted device, a wearable device, a smartphone, a game controller, a game headphone, a game steering wheel, a game pedal, a mouse, a keyboard, a touch screen, an electrical control panel, a touch device, a screen sound-generating device, a vehicle-mounted haptic feedback device, a smart cockpit, a game chair, a massage chair, a massager, a haptic feedback vest, a haptic feedback glove, a haptic feedback belt, a haptic feedback leg device, a hearing aid, a sleep-aiding device, or a haptic feedback network interconnection device.

Description

CROSS-REFERENCE OF RELATED APPLICATIONS This application is a continuation of international application no. PCT/CN2024/082548 filed March 20, 2024, which claims priority to Chinese patent application NO. 202310832430.9, filed July 07, 2023, and the entire disclosures of the above-identified applications is incorporated herein by reference. TECHNICAL FIELD This application relates to the technical field of vibrators, specifically to a moving-magnet vibrator with nonlinear term cancellation. BACKGROUND For the designed vibrators in bone conduction headphones and/or haptic feedback actuators, the moving-magnet design has many advantages. For example, the coil has good heat dissipation, and the movable assembly acting as a load is not heated; the coil adopts a hollow shaft with the magnet provided inside, enabling a compact overall structure. In addition, since the coil is stationary, it avoids the vulnerability of coil connection wires to damage. Moreover, the moving-magnet design enables a high peak force and a high ratio of peak force to moving mass, thereby achieving a high acceleration G-value. The existing designed moving-magnet vibrator often suffer from relatively high nonlinear terms, due to certain deficiencies in the combination of magnets and coils. That is, the force or acceleration value of the movable assembly have relatively high distortion in a low-frequency band or a high-frequency band, which is also referred to as the total harmonic distortion (THD). FIG. 22 is a THD test chart of the existing moving-magnet vibrator. It can be seen that the distortion reaches 99% around 25 Hz, and the distortion reaches 46% around 100 Hz. Such a large distortion indicates that, near low frequencies, the distortion of the audio signal or haptic feedback signal causes the perceived sound quality or haptic feedback to deviate significantly from the actual case. Generally, when the distortion is greater than 10%, it is unacceptable according to audio standards. SUMMARY One objective of the disclosure is to provide a moving-magnet vibrator with nonlinear term cancellation. The moving-magnet vibrator with nonlinear term cancellation includes moving-magnet vibrator body. The moving-magnet vibrator body includes an outer cylinder, a vibration transmission plate, a stator assembly and a movable assembly. The stator assembly includes a coil combination structure, and the movable assembly includes a magnet combination structure. The stator assembly is fixed inside the outer cylinder, the vibration transmission plate is fixed on the outer cylinder, and the movable assembly is fixedly connected to the vibration transmission plate through at least one contact point. The movable assembly moves while the stator assembly remains stationary, and the movable assembly is referred to as a moving component. The movable assembly is configured to be simultaneously subjected to paired electromagnetic forces of push and pull, thereby presenting push-pull structural characterizes. BRIEF DESCRIPTION OF THE DRAWINGS The disclosure is further explained with reference to the accompanying drawings and embodiments. FIG. 1 is a diagram illustrating a cross-sectional view of Embodiments 1 and 2 of the disclosure.FIG. 2 is a diagram illustrating closed magnetic flux curves of a coil and a permanent magnet in Embodiments 1 and 2 of the disclosure.FIG. 3 is a magnetic domain analysis diagram of Embodiments 1 and 2 of the disclosure.FIG. 4 is a diagram illustrating a relationship between magnetic domains and a stator assembly in Embodiments 1 and 2 of the disclosure.FIG. 5 is a force analysis diagram of magnetic domains and a movable assembly in Embodiments 1 and 2 of the disclosure.FIG. 6 is a force analysis diagram of the movable assembly in Embodiments 1 and 2 of the disclosure.FIG. 7 is a diagram illustrating a cross-sectional view of Embodiments 3 and 4 of the disclosure.FIG. 8 is a diagram illustrating closed magnetic flux curves of a coil and a permanent magnet in Embodiments 3 and 4 of the disclosure.FIG. 9 is a magnetic domain analysis diagram of Embodiments 3 and 4 of the disclosure.FIG. 10 is a force analysis diagram of magnetic domains, a movable assembly, and a stator assembly in Embodiments 3 and 4 of the disclosure.FIG. 11 is a force analysis diagram of the magnetic domains and the movable assembly in Embodiments 3 and 4 of the disclosure.FIG. 12 is a diagram illustrating a cross-sectional view of Embodiments 5 and 6 of the disclosure.FIG. 13 is a diagram illustrating closed magnetic flux curves of a coil and a permanent magnet in Embodiments 5 and 6 of the disclosure.FIG. 14 is a magnetic domain analysis diagram of Embodiments 5 and 6 of the disclosure.FIG. 15 is a force analysis diagram of magnetic domains, a stator assembly, and a movable assembly in Embodiments 5 and 6 of the disclosure.FIG. 16 is a force analysis diagram of the magnetic domains and the movable assembly in Embodiments 5 and 6 of the disclosure.FIG. 17 is a diag