Cylindrical two-degree-of-freedom voice coil motor structure

Abstract

The invention discloses a cylindrical two-degree-of-freedom voice coil motor structure, and relates to the technical field of voice coil motors. The integral magnet yoke is composed of a central cylindrical section, a middle cylindrical section and an outer cylindrical section, the bottom end of the integral magnet yoke is connected into a whole, two moving grooves are formed in the bottom end face of the integral magnet yoke, the linear part permanent magnet set is attached to the outer wall of the middle cylindrical section in a sleeving mode according to Halbach distribution, and the top end of the linear part permanent magnet set is fixed to the top magnet yoke in a sleeving mode. Two arc-shaped radial permanent magnets of the deflection part permanent magnet set are attached and fixed to the inner wall of the middle cylinder section, the linear support is in a cylinder shape with the top end closed and inserted between the outer side cylinder section and the linear part permanent magnet set, and two linear motion coils are arranged on the outer wall of the linear support. The deflection support is a cylinder with arc-shaped supporting arms on the two sides and is sleeved outside the central cylindrical section, a deflection motion coil is arranged on the outer wall of the deflection support, and the linear support and the deflection support are fixed through the output shaft. The arrangement mode of the permanent magnets reduces mutual interference of two degrees of freedom, operation is more stable, and leakage flux is reduced by adopting a cylindrical structure as a whole.

Description

Technical Field

[0001] The invention relates to the technical field of voice coil motors, in particular to a cylindrical double-degree-of-freedom voice coil motor structure. Background Art

[0002] The voice coil motor has the characteristics of high response, small size, high precision, etc. It is an electromechanical conversion device, mainly used in the fields of medical, semiconductor, automobile, aerospace, marine vessels, etc., including the production of electronic components, LED production processes, precision measuring instruments, etc. The working principle of the voice coil motor is that the energized coil is subjected to an Ampere force in a fixed magnetic field, and the coil is driven to move by this force.

[0003] There are two types of existing dual-degree-of-freedom voice coil motors: one is a dual-stator voice coil motor connected by mechanical structures such as ball splines; the other is a single-stator flat-plate voice coil motor. Both of these dual-degree-of-freedom voice coil motors have a flat-plate voice coil motor structure, which has serious magnetic leakage. In addition, the dual-stator voice coil motor uses multiple mechanical structures to connect the two degrees of freedom, and the output shaft is long, which is prone to large errors. When the two moving coils of the single-stator flat-plate voice coil motor are close to each other, they will interact with each other, affecting stability. Summary of the invention

[0004] In order to solve the shortcomings of the background technology, the present invention provides a cylindrical dual-degree-of-freedom voice coil motor structure, which has a linear part permanent magnet group arranged in a Halbach array and two parallel linear motion coils on the outside, and a deflection part permanent magnet group and a deflection motion coil on the inside, so as to reduce the mutual interference of the dual degrees of freedom and run more smoothly, and the overall cylindrical structure is adopted to reduce leakage magnetic flux.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a cylindrical dual-degree-of-freedom voice coil motor structure, including an integral yoke, a straight-line permanent magnet group, a deflection permanent magnet group, a straight-line bracket, a deflection bracket and an output shaft, the integral yoke is composed of a central cylindrical section, an intermediate cylindrical section and an outer cylindrical section arranged coaxially from inside to outside, and the bottom end is sealed and connected as a whole, the bottom end surface of the integral yoke is located between the central cylindrical section and the intermediate cylindrical section to open two movement grooves, the two movement grooves are arc-shaped and centrally symmetrically arranged, the straight-line permanent magnet group includes two annular radial permanent magnets and three annular axial permanent magnets, and are coaxially mounted according to Halbach distribution and abut against the outer wall of the intermediate cylindrical section of the integral yoke, and a fixed top is mounted on the top of the outer wall of the intermediate cylindrical section of the integral yoke The deflection part permanent magnet group includes two arc-shaped radial permanent magnets with opposite magnetic pole directions and are arranged symmetrically and fixed to the inner wall of the middle cylindrical section of the integral magnetic yoke. The linear bracket is a cylindrical structure with a closed top and its bottom is coaxially inserted between the inner wall of the outer cylindrical section of the integral magnetic yoke and the linear part permanent magnet group. Two linear motion coils connected in parallel up and down are arranged around the outer wall of the linear bracket. The deflection bracket is a cylindrical structure with arc-shaped support arms on both sides, which is coaxially sleeved on the outside of the central cylindrical section of the integral magnetic yoke. The arc-shaped support arms on both sides of the deflection bracket pass through and are smaller than the corresponding motion grooves for deflection movement. The deflection bracket is provided with a deflection motion coil around the outer wall. The output shaft connecting end coaxially fixes the closed end of the linear bracket with the top of the deflection bracket.

[0006] Furthermore, the straight portion permanent magnet group includes a first annular axial permanent magnet, a second annular radial permanent magnet, a third annular axial permanent magnet, a fourth annular radial permanent magnet and a fifth annular axial permanent magnet arranged from bottom to top, and the Halbach distribution means that the magnetic pole directions of the second annular radial permanent magnet and the fourth annular radial permanent magnet are opposite, and the magnetic pole directions of the first annular axial permanent magnet, the third annular axial permanent magnet and the fifth annular axial permanent magnet are staggered and arranged alternately.

[0007] Furthermore, a thread is provided at the root of the output shaft, and the connecting end of the output shaft is coaxially fixed to the top of the deflection bracket. After the output shaft passes through a preset through hole in the center of the closed end of the linear bracket, the linear bracket and the deflection bracket are fixed by screwing a fastening nut.

[0008] Furthermore, the linear bracket, deflection bracket, output shaft and fastening nut are all made of non-magnetic materials.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention sets a straight-line permanent magnet group arranged in a Halbach array on the outside, optimizes the distribution of magnetic lines of force, concentrates the magnetic lines of force on the outside, enhances the magnetic flux density of the straight-line motion part, and reduces the influence on the permanent magnet group of the deflection part, thereby increasing the utilization efficiency of the magnetic field. The structure is simple, the mutual interference of the straight-line and deflection dual-degree-of-freedom motions is reduced, the operation is more stable, and two parallel linear motion coils are set on the linear bracket, which helps to increase the linear thrust of the voice coil motor and reduce heat generation. The overall cylindrical structure is used as the basis to effectively reduce the motor leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a longitudinal cross-sectional schematic diagram of the voice coil motor structure of the present invention;

[0011] Figure 2 It is a schematic diagram of a moving groove provided at the bottom of the integral magnetic yoke in the present invention;

[0012] Figure 3 Schematic diagram of four annular surfaces of the integral magnetic yoke of the present invention;

[0013] Figure 4 It is a schematic diagram of the magnetic circuit distribution of the voice coil motor structure of the present invention.

[0014] In the figure: 1. integral yoke; 11. first annular surface; 12. second annular surface; 13. third annular surface; 14. fourth annular surface; 15. motion groove; 16. top yoke; 21. first annular axial permanent magnet; 22. second annular radial permanent magnet; 23. third annular axial permanent magnet; 24. fourth annular radial permanent magnet; 25. fifth annular axial permanent magnet; 3. arc-shaped radial permanent magnet; 4. linear bracket; 41. linear motion coil; 5. deflection bracket; 51. deflection motion coil; 6. output shaft. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] like Figure 1 to Figure 4 As shown, a cylindrical dual-degree-of-freedom voice coil motor structure includes an integral yoke 1, a linear portion permanent magnet group, a deflection portion permanent magnet group, a linear bracket 4, a deflection bracket 5 and an output shaft 6.

[0017] Combination Figure 1 to Figure 3As shown, the integral magnetic yoke 1 is composed of a central cylindrical section, an intermediate cylindrical section and an outer cylindrical section which are coaxially arranged from inside to outside, and the bottom end is sealed and connected as a whole. The bottom end surface of the integral magnetic yoke 1 is located between the central cylindrical section and the intermediate cylindrical section, and two movement grooves 15 are opened. The two movement grooves 15 are arc-shaped and centrally symmetrically arranged to allow the deflection bracket 5 to pass through and allow it to deflect at a certain angle.

[0018] Combination Figure 1 As shown, the straight portion permanent magnet group includes two annular radial permanent magnets and three annular axial permanent magnets, and are coaxially mounted against the outer wall of the middle cylindrical section of the integral magnetic yoke 1 according to the Halbach distribution. The top of the outer wall of the middle cylindrical section of the integral magnetic yoke 1 is mounted and fixed with the top magnetic yoke 16 and is tightly pressed onto the top of the straight portion permanent magnet group. Specifically, the straight part permanent magnet group can be divided into a first annular axial permanent magnet 21, a second annular radial permanent magnet 22, a third annular axial permanent magnet 23, a fourth annular radial permanent magnet 24 and a fifth annular axial permanent magnet 25 arranged from bottom to top, wherein the Halbach distribution means that the magnetic pole directions of the second annular radial permanent magnet 22 and the fourth annular radial permanent magnet 24 are opposite, for example, the S pole of the second annular radial permanent magnet 22 is located inside the ring and the N pole is located outside the ring, the S pole of the fourth annular radial permanent magnet 24 is located outside the ring and the N pole is located inside the ring, the magnetic pole directions of the first annular axial permanent magnet 21, the third annular axial permanent magnet 23 and the fifth annular axial permanent magnet 25 are staggered and arranged alternately, for example, the S pole of the first annular axial permanent magnet 21 is located at the bottom end of the ring and the N pole is located at the top end of the ring, the S pole of the third annular axial permanent magnet 23 is located at the top end of the ring and the N pole is located at the bottom end of the ring, the S pole of the fifth annular axial permanent magnet 25 is located at the bottom end of the ring and the N pole is located at the top end of the ring.

[0019] Combination Figure 2 As shown, the deflection part permanent magnet group includes two arc-shaped radial permanent magnets 3 with opposite magnetic pole directions and are arranged symmetrically and fixed on the inner wall of the middle cylindrical section of the integral magnetic yoke 1. For example, the S pole of one of the arc-shaped radial permanent magnets 3 is located on the outer side of the arc and abuts against the inner wall of the middle cylindrical section of the integral magnetic yoke 1, and the N pole of the other arc-shaped radial permanent magnet 3 is located on the outer side of the arc and abuts against the inner wall of the middle cylindrical section of the integral magnetic yoke 1.

[0020] The bottom ends of the straight-line permanent magnet group and the deflection permanent magnet group are both tightly fitted to the inner bottom surface of the integral magnetic yoke 1 .

[0021] Combination Figure 1As shown, the linear support 4 is a cylindrical structure with a closed top and its bottom is coaxially inserted between the inner wall of the outer cylindrical section of the integral magnetic yoke 1 and the permanent magnet group of the linear part. The outer wall of the linear support 4 is ringed with two linear motion coils 41 connected in parallel up and down. The deflection support 5 is a cylindrical structure with arc-shaped arms on both sides, which is coaxially sleeved on the outside of the central cylindrical section of the integral magnetic yoke 1. The arc-shaped arms on both sides of the deflection support 5 pass through and are smaller than the corresponding motion slots 15 for deflection movement. The outer wall of the deflection support 5 is ringed with a deflection motion coil 51. The connecting end of the output shaft 6 coaxially fixes the closed end of the linear support 4 with the top of the deflection support 5. A thread can be set at the root of the output shaft 6. The connecting end of the output shaft 6 is coaxially fixed to the top of the deflection support 5. After the output shaft 6 passes through the preset through hole in the center of the closed end of the linear support 4, the linear support 4 and the deflection support 5 are fixed by screwing the fastening nut.

[0022] The yoke part is made of high magnetic conductivity material, including the integral yoke 1 and the top yoke 16, and the linear bracket 4, the deflection bracket 5, the output shaft 6 and the fastening nut are all made of non-magnetic conductive material.

[0023] Combination Figure 3As shown, for the convenience of description, the inner wall of the outer cylindrical section of the integral yoke 1 is defined as the first annular surface 11, the outer wall of the middle cylindrical section is defined as the second annular surface 12, the inner wall of the middle cylindrical section is defined as the third annular surface 13, and the side wall of the center cylindrical section is defined as the fourth annular surface 14. The cylindrical dual-degree-of-freedom voice coil motor structure mainly includes a first magnetic circuit A, a second magnetic circuit B, a third magnetic circuit C, and a fourth magnetic circuit D, wherein the first magnetic circuit A: the magnetic flux lines start from the N pole of the fourth annular radial permanent magnet 24, and pass through the S pole of the fifth annular axial permanent magnet 25, the N pole of the fifth annular axial permanent magnet 25, the top magnetic yoke 16, the first annular surface 11, the upper linear motion coil 41, and then return to the S pole of the fourth annular radial permanent magnet 24; the second magnetic circuit B: the magnetic flux lines start from the N pole of the second annular radial permanent magnet 22, and pass through the lower linear motion coil 41, the first annular surface 11, the upper linear motion coil 41, the S pole of the fourth annular radial permanent magnet 24, the N pole of the fourth annular radial permanent magnet 24, the S pole of the third annular axial permanent magnet 23, and the N pole of the fourth annular radial permanent magnet 24. The third magnetic circuit C: the magnetic flux lines start from the N pole of the second annular radial permanent magnet 22, and pass through the linear motion coil 41 below, the first annular surface 11, the bottom of the integral magnetic yoke 1, the S pole of the first annular axial permanent magnet 21, the N pole of the first annular axial permanent magnet 21, and then return to the S pole of the second annular radial permanent magnet 22; the fourth magnetic circuit D: the magnetic flux lines start from the N pole of the right arc-shaped radial permanent magnet 3, and pass through the deflection motion coil 51 and the central cylindrical section of the integral magnetic yoke 1, the S pole of the left arc-shaped radial permanent magnet 3, the N pole of the left arc-shaped radial permanent magnet 3, the third annular surface 13, the bottom of the integral magnetic yoke 1, and then return to the S pole of the right arc-shaped radial permanent magnet 3.

[0024] When the coil of the cylindrical dual-degree-of-freedom voice coil motor structure is energized, the linear motion coil 41 is subjected to a force in the same direction, causing the output shaft 6 to output a linear motion, while the inner deflection motion coil 51 can change the output angle of the output shaft 6 to achieve dual degrees of freedom. The specific motion form is as follows:

[0025] When a clockwise current is passed through the deflection motion coil 51, the left side is acted on by the Lorentz force and moves outward perpendicular to the paper surface, while the right side is acted on by the Lorentz force and moves inward perpendicular to the paper surface;

[0026] When a counterclockwise current is passed through the deflection motion coil 51, the left side is acted on by the Lorentz force and moves inward perpendicular to the paper surface, while the right side is acted on by the Lorentz force and moves outward perpendicular to the paper surface;

[0027] When the current of the lower linear motion coil 41 enters from the left side and flows out from the right side, the current of the upper linear motion coil 41 enters from the right side and flows out from the left side, at this time, the linear support 4 moves upward as a whole under the action of the Lorentz force;

[0028] When the current of the lower linear motion coil 41 enters from the right and flows out from the left, the current of the upper linear motion coil 41 enters from the left and flows out from the right. At this time, the linear support 4 moves downward as a whole under the action of the Lorentz force.

[0029] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms of assembly without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0030] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A cylindrical dual-degree-of-freedom voice coil motor structure, characterized in that: The invention comprises an integral magnetic yoke (1), a linear permanent magnet group, a deflection permanent magnet group, a linear bracket (4), a deflection bracket (5) and an output shaft (6); the integral magnetic yoke (1) is composed of a central cylindrical section, a middle cylindrical section and an outer cylindrical section arranged coaxially from inside to outside, and the bottom end is sealed and connected as a whole; the bottom end surface of the integral magnetic yoke (1) is located between the central cylindrical section and the middle cylindrical section and has two movement grooves (15); the two movement grooves (15) are arc-shaped and arranged symmetrically; the linear permanent magnet group comprises two annular radial permanent magnets and three annular axial permanent magnets, and are coaxially mounted against the outer wall of the middle cylindrical section of the integral magnetic yoke (1) according to the Halbach distribution; the top end of the outer wall of the middle cylindrical section of the integral magnetic yoke (1) is mounted with a fixed top magnetic yoke (16) and is tightly pressed on the top end of the linear permanent magnet group; the deflection permanent magnet group comprises two annular radial permanent magnets and three annular axial permanent magnets, and are coaxially mounted according to the Halbach distribution and are pressed against the outer wall of the middle cylindrical section of the integral magnetic yoke (1); the top end of the outer wall of the middle cylindrical section of the integral magnetic yoke (1) is mounted with a fixed top magnetic yoke (16) and is tightly pressed on the top end of the linear permanent magnet group; The partial permanent magnet group comprises two arc-shaped radial permanent magnets (3) with opposite magnetic pole directions and are arranged symmetrically and fixed to the inner wall of the middle cylindrical section of the integral magnetic yoke (1); the linear support (4) is a cylindrical structure with a closed top and its bottom end is coaxially inserted between the inner wall of the outer cylindrical section of the integral magnetic yoke (1) and the linear partial permanent magnet group; the outer wall of the linear support (4) is ringed with two linear motion coils (41) connected in parallel up and down; the deflection support (5) is a cylindrical structure with arc-shaped support arms on both sides and is coaxially sleeved on the outside of the central cylindrical section of the integral magnetic yoke (1); the arc-shaped support arms on both sides of the deflection support (5) pass through and are smaller than the corresponding motion slots (15) for deflection movement; the outer wall of the deflection support (5) is ringed with a deflection motion coil (51); the output shaft (6) connection end coaxially fixes the closed end of the linear support (4) and the top of the deflection support (5).

2. A cylindrical dual-degree-of-freedom voice coil motor structure according to claim 1, characterized in that: The straight portion permanent magnet group comprises a first annular axial permanent magnet (21), a second annular radial permanent magnet (22), a third annular axial permanent magnet (23), a fourth annular radial permanent magnet (24) and a fifth annular axial permanent magnet (25) arranged from bottom to top, wherein the Halbach distribution means that the magnetic pole directions of the second annular radial permanent magnet (22) and the fourth annular radial permanent magnet (24) are opposite, and the magnetic pole directions of the first annular axial permanent magnet (21), the third annular axial permanent magnet (23) and the fifth annular axial permanent magnet (25) are staggered and arranged alternately.

3. A cylindrical dual-degree-of-freedom voice coil motor structure according to claim 1 or 2, characterized in that: The output shaft (6) is provided with a thread at its root, and the connecting end of the output shaft (6) is coaxially fixed to the top of the deflection bracket (5). After the output shaft (6) passes through a preset through hole at the center of the closed end of the linear bracket (4), the linear bracket (4) and the deflection bracket (5) are fixed by screwing a fastening nut.

4. The cylindrical dual-degree-of-freedom voice coil motor structure according to claim 3, characterized in that: The linear support (4), the deflection support (5), the output shaft (6) and the fastening nut are all made of non-magnetic conductive materials.

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