Voice coil motor with a protective layer on the inner ring

Abstract

This utility model discloses a voice coil motor with a protective layer on the inner ring, including a housing assembly, an inner cavity containing a coil assembly, a magnetic circuit assembly, an elastic metal sheet, and a protective layer. The magnetic circuit assembly is located inside the coil assembly, and the protective layer is located between the coil assembly and the magnetic circuit assembly. The coil assembly includes an insulating wire frame located inside the housing assembly with an open structure at both the top and bottom. Two coils are fixedly connected vertically inside the inner cavity of the insulating wire frame. By constraining the coil with a metal sleeve, the air gap magnetic flux density is effectively increased, resulting in a corresponding increase in the thrust and response speed of the voice coil motor. This meets the high dynamic performance requirements of scenarios such as rapid focusing and precise positioning of cameras, and significantly improves the magnetic circuit performance. The metal sleeve fully covers the inner ring of the coil, and the mechanical interlocking structure of the groove and rib improves the wear resistance of the coil, reduces the risk of insulation failure, and effectively extends the service life of the voice coil motor, making it particularly suitable for high-frequency vibration environments.

Description

Technical Field

[0001] This utility model relates to the field of voice coil motor technology, and in particular to a voice coil motor with a protective layer on the inner ring. Background Technology

[0002] A voice coil motor is a device that converts electrical energy into mechanical energy and enables linear motion with a limited swing angle.

[0003] When a voice coil motor is working, the inner coil is prone to wear and insulation failure due to friction, electromagnetic environment, etc., which affects the reliability and service life of the motor. Moreover, the existing structure does not adequately protect the inner coil and optimize the air gap magnetic flux density.

[0004] To address this, a voice coil motor with a protective layer on the inner ring is proposed. Utility Model Content

[0005] The purpose of this invention is to provide a voice coil motor with a protective layer on the inner ring, in order to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0007] A voice coil motor with a protective layer on the inner ring includes:

[0008] The housing assembly has an inner cavity containing a coil assembly, a magnetic circuit assembly, an elastic metal sheet, and a protective layer. The magnetic circuit assembly is located within the inner cavity of the coil assembly, and the protective layer is disposed between the coil assembly and the magnetic circuit assembly.

[0009] The coil assembly includes an insulating wire frame located inside the cavity of the housing assembly, with an open structure at both the top and bottom. The cavity of the insulating wire frame has two coils fixedly connected vertically.

[0010] The protective layer consists of metal sleeves nested within the inner coil of the coil. The metal sleeves have a cylindrical structure, and their outer diameter is interference-fitted with the inner diameter of the coil.

[0011] As a preferred technical solution, the two ends of the metal sleeve extend to the two end faces of the coil and are flush with them, and are made of SUS material.

[0012] As a preferred technical solution, the contact surface between the metal sleeve and the coil is provided with a plurality of grooves, and the plurality of grooves are distributed at equal angles along the circumference of the metal sleeve.

[0013] As a preferred technical solution, the metal sleeve is integrally formed with a number of ribs, which are distributed at equal angles along the circumference of the metal sleeve, and the ribs are spaced apart from the grooves. The cross-sections of the grooves and the ribs are both rectangular or trapezoidal.

[0014] As a preferred technical solution, the housing assembly includes an upper cover and a lower base. The upper cover is fastened to the top of the lower base and is used to fix the insulating wire frame by means of a snap-fit ​​structure.

[0015] As a preferred technical solution, a washer is fixedly connected to the middle of the inner cavity of the insulating wire frame. The washer is located between the two coils and is used to isolate the two coils.

[0016] As a preferred technical solution, the magnetic circuit assembly is movably disposed in the inner cavity of the coil, and an elastic metal sheet is fixedly connected to one end of each of the two permanent magnet shafts of the magnetic circuit assembly that are opposite to each other. The metal sleeve is located between the inner coil of the coil and the stator yoke of the magnetic circuit assembly.

[0017] As a preferred technical solution, the outer edge of one of the elastic metal sheets is fixed to the top of the upper cover and the top of the insulating wire frame by welding, and the outer edge of the other elastic metal sheet is fixed to the bottom of the lower seat and the bottom of the insulating wire frame by welding.

[0018] This utility model has at least the following beneficial effects:

[0019] This application effectively increases the air gap magnetic flux density by constraining the coil with a metal sleeve, thereby increasing the thrust and response speed of the voice coil motor. This meets the high dynamic performance requirements of scenarios such as rapid focusing and precise positioning of cameras, and significantly improves the magnetic circuit performance. The metal sleeve fully covers the inner coil of the coil, and the mechanical interlocking structure of the groove and ribs improves the wear resistance of the coil, reduces the risk of insulation failure, and effectively extends the service life of the voice coil motor, making it particularly suitable for high-frequency vibration environments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is an exploded view of the structure of this utility model;

[0022] Figure 3 This is a cross-sectional view of the structure of this utility model;

[0023] Figure 4 This is a partial exploded view of the structure of this utility model;

[0024] Figure 5 This is a schematic diagram of the structure of the metal sleeve of this utility model.

[0025] In the diagram: 100, housing assembly; 110, top cover; 120, lower base; 200, coil assembly; 210, insulating wire frame; 220, coil; 230, washer; 300, magnetic circuit assembly; 400, elastic metal sheet; 500, metal sleeve; 510, groove; 520, rib. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Please see Figures 1-5 This utility model provides a voice coil motor with an inner protective layer, including a housing assembly 100, a coil assembly 200, a magnetic circuit assembly 300, an elastic metal sheet 400, and a protective layer. The coil assembly 200, the magnetic circuit assembly 300, the elastic metal sheet 400, and the protective layer are all disposed within the inner cavity of the housing assembly 100. The magnetic circuit assembly 300 is located within the inner cavity of the coil assembly 200, and the protective layer is disposed between the coil assembly 200 and the magnetic circuit assembly 300. The coil assembly 200 includes a voice coil motor located within the inner cavity of the housing assembly 100 and with its top... The insulating wire frame 210, which has an open bottom structure, has two coils 220 fixedly connected to each other in its inner cavity. The protective layer consists of metal sleeves 500 nested inside the inner rings of the coils 220. The metal sleeves 500 have a cylindrical structure and their outer diameter is interference-fitted with the inner diameter of the coils 220. The interference fit between the metal sleeves 500 and the coils 220 ensures that the protective layer fits tightly with the inner rings of the coils 220, preventing the increase of magnetic leakage caused by assembly gaps, while improving the overall structural integrity and keeping the voice coil motor stable during high-frequency operation.

[0028] The metal sleeve 500 extends to both ends of the coil 220 and is flush with them, and is made of SUS material. The metal sleeve 500 is flush with the end face of the coil 220, fully covering the inner ring of the coil 220, avoiding direct exposure of the wires at both ends and reducing friction and wear. The SUS material has both magnetic permeability and wear resistance, which optimizes the magnetic circuit and extends the life of the protective layer.

[0029] The contact surface between the metal sleeve 500 and the coil 220 is provided with a number of grooves 510, which are distributed at equal angles along the circumference of the metal sleeve 500. The equal angle distribution of the grooves 510 increases the contact area between the metal sleeve 500 and the coil 220, improves the friction, prevents the protective layer from moving axially, and at the same time, the grooves 510 can help optimize the magnetic circuit distribution, making the air gap magnetic density more uniform.

[0030] The metal sleeve 500 has several ribs 520 integrally formed on it. The ribs 520 are distributed at equal angles along the circumference of the metal sleeve 500, and the ribs 520 and the grooves 510 are spaced apart. The cross-sections of the grooves 510 and the ribs 520 are rectangular or trapezoidal. The spaced arrangement of the ribs 520 and the grooves 510 increases the contact area while maintaining the circumferential strength of the metal sleeve 500, and avoids the weakening of the overall structure of the metal sleeve 500 due to too many grooves 510. The rectangular or trapezoidal cross-section design takes into account both mechanical interlocking strength and magnetic circuit conduction efficiency.

[0031] The housing assembly 100 includes an upper cover 110 and a lower base 120. The upper cover 110 is fastened to the top of the lower base 120 and is fixed to the insulation wire frame 210 by means of a snap-fit ​​structure. The upper cover 110 and the lower base 120 fix the insulation wire frame 210 by snap-fit, which simplifies the assembly process and improves production efficiency. At the same time, the snap-fit ​​structure can provide sufficient clamping force to ensure the stability of the coil assembly 200.

[0032] Among them, a washer 230 is fixedly connected to the middle of the inner cavity of the insulating wire frame 210. The washer 230 is located between the two coils 220 and is used to isolate the two coils 220. The washer 230 isolates the two coils 220, prevents short circuit between the two coils 220, and provides axial positioning to ensure the magnetic circuit symmetry of the dual coil structure and improve the motion accuracy of the voice coil motor.

[0033] The magnetic circuit assembly 300 is movably disposed within the inner cavity of the coil 220, and an elastic metal sheet 400 is fixedly connected to one end of each of the two permanent magnet shafts of the magnetic circuit assembly 300 facing away from each other. The metal sleeve 500 is located between the inner ring of the coil 220 and the stator yoke of the magnetic circuit assembly 300. The magnetic circuit assembly 300 is movably disposed within the inner cavity of the coil 220 and works with the elastic metal sheet 400 to achieve reciprocating motion. The metal sleeve 500 is located between the inner ring of the coil 220 and the stator yoke to form a magnetic conductive path, reduce magnetic resistance, and improve thrust output.

[0034] One of the elastic metal sheets 400 is fixed by welding to the top of the upper cover 110 and the insulating wire frame 210, and the other elastic metal sheet 400 is fixed by welding to the bottom of the lower seat 120 and the insulating wire frame 210. The elastic metal sheets 400 are fixed by welding, which has high connection strength and can withstand the alternating load in the high-frequency movement of the voice coil motor. At the same time, it provides elastic support for the magnetic circuit assembly 300 and ensures smooth movement.

[0035] The working principle of this utility model is as follows:

[0036] When the voice coil motor is energized, a current is generated in the coil 220. Within the magnetic field formed by the permanent magnet shaft of the magnetic circuit assembly 300 and the stator yoke, the coil 220 experiences an Ampere force, resulting in axial movement. At this time, a metal sleeve 500 made of SUS material is fitted inside the coil 220. Its magnetic permeability constrains the direction of the magnetic field lines, reducing magnetic leakage. In the air gap magnetic circuit formed between the metal sleeve 500 and the stator yoke, the metal sleeve 500 gathers the magnetic field lines that might otherwise diverge, increasing the air gap magnetic flux density and consequently increasing the thrust, making the voice coil motor more responsive.

[0037] The grooves 510 and ribs 520 are distributed at intervals. On the one hand, the concave and convex structure increases the contact area with the coil 220, improves the mechanical engagement strength, and prevents the metal sleeve 500 from sliding relative to the coil 220. On the other hand, the ribs 520 maintain the structural strength of the metal sleeve 500, prevent the circumferential strength from being weakened due to the grooves 510, and ensure the continuity of the magnetic circuit.

[0038] The magnetic circuit assembly 300 is welded and fixed to the upper cover 110 and the lower base 120 by elastic metal sheets 400 at both ends. When the coil 220 drives the magnetic circuit assembly 300 to move, the elastic metal sheet 400 provides a reset force, while the metal sleeve 500 protects the inner ring of the coil 220 from friction and wear caused by the reciprocating motion of the magnetic circuit assembly 300, thus extending the life of the coil 220.

[0039] All parts not described in this utility model are the same as or can be implemented using existing technology. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this utility model, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A voice coil motor having a protective layer on an inner ring, characterized by, include: A housing assembly (100) has an inner cavity comprising a coil assembly (200), a magnetic circuit assembly (300), an elastic metal sheet (400), and a protective layer. The magnetic circuit assembly (300) is located within the inner cavity of the coil assembly (200), and the protective layer is disposed between the coil assembly (200) and the magnetic circuit assembly (300). The coil assembly (200) includes an insulating wire frame (210) located inside the cavity of the housing assembly (100) and having an open structure at both the top and bottom. The cavity of the insulating wire frame (210) has two coils (220) fixedly connected vertically. The protective layer consists of metal sleeves (500) nested inside the inner ring of the coil (220). The metal sleeves (500) have a cylindrical structure and their outer diameter is interference-fitted with the inner diameter of the coil (220).

2. The voice coil motor with a protective layer for the inner ring according to claim 1, characterized in that: The two ends of the metal sleeve (500) extend to and are flush with the two end faces of the coil (220) and are made of SUS material.

3. The voice coil motor with a protective layer for the inner ring according to claim 2, characterized in that: The contact surface between the metal sleeve (500) and the coil (220) is provided with a plurality of grooves (510), and the plurality of grooves (510) are distributed at equal angles along the circumference of the metal sleeve (500).

4. The voice coil motor with a protective layer for the inner ring according to claim 3, characterized in that: The metal sleeve (500) has a plurality of ribs (520) integrally formed on it. The plurality of ribs (520) are distributed at equal angles along the circumference of the metal sleeve (500), and the ribs (520) and the grooves (510) are spaced apart. The cross sections of the grooves (510) and the ribs (520) are both rectangular or trapezoidal.

5. The voice coil motor with a protective layer for the inner ring according to claim 4, characterized in that: The housing assembly (100) includes an upper cover (110) and a lower base (120). The upper cover (110) is fastened to the top of the lower base (120) and is used to fix the insulating wire frame (210) by means of a snap-fit ​​structure.

6. The voice coil motor with a protective layer for the inner ring according to claim 5, characterized in that: A washer (230) is fixedly connected to the middle of the inner cavity of the insulating wire frame (210). The washer (230) is located between the two coils (220) and is used to isolate the two coils (220).

7. The voice coil motor with a protective layer for the inner ring according to claim 6, characterized in that: The magnetic circuit assembly (300) is movably disposed in the inner cavity of the coil (220), and an elastic metal sheet (400) is fixedly connected to one end of each of the two permanent magnet shafts of the magnetic circuit assembly (300) facing away from each other. The metal sleeve (500) is located between the inner ring of the coil (220) and the stator yoke of the magnetic circuit assembly (300).

8. The voice coil motor with a protective layer for the inner ring according to claim 6, characterized in that: The outer edge of one of the elastic metal sheets (400) is fixed by welding between the top cover (110) and the top of the insulating wire frame (210), and the outer edge of the other elastic metal sheet (400) is fixed by welding between the bottom seat (120) and the bottom of the insulating wire frame (210).

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