Voice coil motor

Abstract

The invention provides a voice coil motor, which comprises a motor shell, a stator assembly, a rotor assembly and an output shaft, and is characterized in that the stator assembly comprises a first stator yoke part and a second stator yoke part, and the first stator yoke part and the second stator yoke part are of annular structures; the rotor assembly comprises an axial magnetic ring, a first radial magnetic ring and a second radial magnetic ring, the first radial magnetic ring and the second radial magnetic ring are coaxially connected to the two axial ends of the axial magnetic ring through a rotor yoke part respectively, and the first radial magnetic ring is arranged on the inner side of the first stator yoke part in a sliding mode in the axial direction. The second radial magnetic ring is arranged on the inner side of the second stator yoke part in a sliding manner along the axial direction; a first gap is arranged between the first stator yoke part and the first radial magnetic ring, a second gap is arranged between the second stator yoke part and the second radial magnetic ring, and the size of the first gap is smaller than that of the second gap. The motor provides gravity compensation for the rotor assembly, and the volume space and the manufacturing cost of the motor can be effectively prevented from being increased.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and more particularly, to a voice coil motor. Background Art

[0002] A voice coil motor is a special form of direct drive motor. It has characteristics such as simple structure, small volume, high speed, high acceleration, and fast response. In recent years, with the improvement of the performance requirements for high-speed and high-precision positioning systems and the rapid development of voice coil motor technology, voice coil motors are not only widely used in precision positioning systems such as disk and laser disc positioning, but also widely used in many different forms of high-acceleration and high-frequency excitation. Chinese Patent (202011381314.2) discloses a voice coil motor. Three permanent magnets are added to the stator assembly of this voice coil motor, and the magnetic buoyancy force between it and the main permanent magnet of the mover assembly is used to compensate for part of the gravity of the moving mechanism. This method will not only cause a significant increase in cost, but also requires a large volume to add permanent magnets, and there are certain limitations in engineering applications. Chinese Patent (202310277623.2) discloses a voice coil motor. This voice coil motor adds permanent magnets to the stator assembly, and the magnetic resistance between it and the stator yoke and the fixed shaft is used to compensate for part of the gravity of the moving mechanism. This method also requires an increase in volume space and cost. Summary of the Invention

[0003] The technical problem to be solved by the present invention is that the structural setting for gravity compensation increases the volume space and manufacturing cost of the motor. To overcome the defects of the above prior art, the present invention provides a voice coil motor.

[0004] The present invention provides a voice coil motor, including a motor housing and a stator assembly and a mover assembly installed in the motor housing. An output shaft is connected to the mover assembly, and one end of the output shaft away from the mover assembly extends out of the motor housing. The stator assembly includes a first stator yoke portion and a second stator yoke portion. The first stator yoke portion and the second stator yoke portion are coaxially and integrally connected, and the first stator yoke portion is located above the second stator yoke portion. Both the first stator yoke portion and the second stator yoke portion are in a ring structure. The mover assembly includes an axial magnetic ring, a first radial magnetic ring, and a second radial magnetic ring. The first radial magnetic ring and the second radial magnetic ring are coaxially connected to the axial magnetic ring at both axial ends through a mover yoke portion respectively. The magnetic directions of the first radial magnetic ring and the second radial magnetic ring are set in opposite directions. The first radial magnetic ring slides axially inside the first stator yoke portion, and the second radial magnetic ring slides axially inside the second stator yoke portion. A first gap is provided between the inner side wall of the first stator yoke portion and the outer side wall of the first radial magnetic ring, and a second gap is provided between the inner side wall of the second stator yoke portion and the outer side wall of the second radial magnetic ring. The size of the first gap is smaller than the size of the second gap.

[0005] Compared with the prior art, the voice coil motor of the present application has the following advantages: By providing a first stator yoke, a second stator yoke, an axial magnetic ring, a mover yoke, a first radial magnetic ring and a second radial magnetic ring, the internal magnetic circuit distribution of each component forms a closed magnetic circuit. At the same time, the size of the first gap is smaller than that of the second gap. According to the magnetic characteristics of the magnet, the closer the distance between adjacent magnets, the greater the magnetic attraction force. The mutual magnetic attraction force between the first stator yoke and the first radial magnetic ring is greater than the mutual magnetic attraction force between the second stator yoke and the second radial magnetic ring. Even if the mover assembly as a whole has an axial upward magnetic resistance, thus providing gravity compensation for the self-weight of the mover assembly, improving the thrust and reducing the fluctuation. At the same time, this compensation structure can effectively avoid increasing the volume space and manufacturing cost of the motor, realizing the miniaturization development of the motor and reducing the cost.

[0006] In a possible implementation manner, the inner diameters of the first stator yoke are set to be the same, the inner diameter of the second stator yoke gradually increases from top to bottom, and the inner diameter of the second stator yoke is greater than that of the first stator yoke. The outer diameters of the first radial magnetic ring and the second radial magnetic ring are set to be the same.

[0007] Compared with the prior art, adopting the above technical solution can achieve that the size of the first gap is smaller than that of the second gap.

[0008] In a possible implementation manner, the inner side wall of the second stator yoke is arranged as an inclined surface.

[0009] Compared with the prior art, adopting the above technical solution can achieve that the size of the first gap is smaller than that of the second gap, ensuring that the mover assembly has a stable axial upward magnetic resistance and stable gravity compensation.

[0010] In a possible implementation manner, the inner side wall of the second stator yoke is arranged as a stepped surface.

[0011] Compared with the prior art, adopting the above technical solution can achieve that the size of the first gap is smaller than that of the second gap, ensuring that the mover assembly has a stable axial upward magnetic resistance and stable gravity compensation.

[0012] In a possible implementation manner, a guiding assembly for guiding the movement of the mover assembly is provided in the motor housing. The guiding assembly includes an upper guiding seat, an upper guiding ring, a lower guiding seat and a lower guiding ring. The upper guiding seat is fixedly installed in the motor housing and located above the first stator yoke. The upper guiding ring is slidably arranged on the upper guiding seat, and the upper guiding ring is coaxially connected to the first radial magnetic ring. The lower guiding seat is fixedly installed in the motor housing and located below the second stator yoke. The lower guiding ring is slidably arranged on the lower guiding seat, and the lower guiding ring is coaxially connected to the second radial magnetic ring.

[0013] Compared with the prior art, adopting the above technical solution can achieve the stable sliding of the first radial magnetic ring and the second radial magnetic ring along the axial direction, and improve the sliding reliability of the mover assembly.

[0014] In a possible implementation manner, an upper sliding bearing is provided between the upper guide seat and the upper guide ring, and a lower sliding bearing is provided between the lower guide seat and the lower guide ring.

[0015] Compared with the prior art, adopting the above technical solution can improve the sliding reliability of the upper guide ring and the lower guide ring.

[0016] In a possible implementation manner, an encoder and a housing for protecting the encoder are provided on the outer side of the motor housing, and an encoding magnet for the encoder to sense is provided on the upper guide ring.

[0017] Compared with the prior art, adopting the above technical solution can achieve the feedback of the mover position signal and improve the motor control accuracy and response speed.

[0018] In a possible implementation manner, the motor housing includes an outer shell, a flange cover and an end cover. The flange cover is connected to the lower end of the outer shell. A through hole for the output shaft to pass through is provided on the flange cover, and a bearing slidably matched with the output shaft is provided in the through hole. The end cover is connected to the upper end of the outer shell, and the encoder and the housing are installed on the outer side of the end cover.

[0019] Compared with the prior art, adopting the above technical solution is beneficial to the assembly of the motor and improves the output reliability of the output shaft at the same time.

[0020] In a possible implementation manner, the stator assembly further includes a first winding coil, a second winding coil and a coil skeleton. The first winding coil is arranged on the inner side wall of the first stator yoke through the coil skeleton, the second winding coil is arranged on the inner side wall of the second stator yoke through the coil skeleton, and the first winding coil and the second winding coil are axially spaced apart.

[0021] Compared with the prior art, adopting the above technical solution can achieve the moving output of the output shaft.

[0022] In a possible implementation manner, the first winding coil and the second winding coil are potted in the coil skeleton with potting resin glue.

[0023] Compared with the prior art, adopting the above technical solution can achieve the fixation and heat dissipation of the winding coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the present invention; Figure 2 is a structural schematic diagram of the stator assembly; Figure 3 Schematic structural diagram of the mover assembly; Figure 4 Schematic magnetic circuit diagram; Figure 5 Schematic structural diagram of the first stator yoke and the second stator yoke in this embodiment; Figure 6 Schematic structural diagrams of other embodiments of the first stator yoke and the second stator yoke; Figure 7 Schematic of the structure of the mover assembly of other embodiments Figure 1 ; Figure 8 Schematic of the structure of the mover assembly of other embodiments Figure 2 ; Description of reference numerals: 1. Motor housing; 11. Outer shell; 12. Flange cover; 121. Through hole; 13. End cover; 2. Stator assembly; 21. First stator yoke; 22. Second stator yoke; 23. First winding coil; 24. Second winding coil; 25. Coil skeleton; 3. Mover assembly; 31. Axial magnetic ring; 32. First radial magnetic ring; 33. Second radial magnetic ring; 34. Mover yoke; 4. Output shaft; 5. First gap; 6. Second gap; 7. Guide assembly; 71. Upper guide seat; 72. Upper guide ring; 73. Lower guide seat; 74. Lower guide ring; 75. Upper sliding bearing; 76. Lower sliding bearing; 8. Encoder; 9. Coding magnet; 10. Cover housing. Detailed implementation manners

[0025] First of all, those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0026] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0027] In the embodiments of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0028] The following further describes the present application in detail with reference to the drawings and specific embodiments.

[0029] See Figures 1 to 5 , an embodiment of the present application discloses a voice coil motor, including a motor housing 1, a stator assembly 2 and a mover assembly 3 installed in the motor housing 1. An output shaft 4 is connected to the mover assembly 3. One end of the output shaft 4 away from the mover assembly 3 extends out of the motor housing 1. The stator assembly 2 includes a first stator yoke portion 21 and a second stator yoke portion 22. The first stator yoke portion 21 and the second stator yoke portion 22 are coaxially and integrally connected, and the first stator yoke portion 21 is located above the second stator yoke portion 22. Both the first stator yoke portion 21 and the second stator yoke portion 22 are in a ring structure. The inner diameters of the first stator yoke portion 21 are set to be the same. The inner diameter of the second stator yoke portion 22 gradually increases from top to bottom, and the inner diameter of the second stator yoke portion 22 is larger than the inner diameter of the first stator yoke portion 21. The mover assembly 3 includes an axial magnetic ring 31, a first radial magnetic ring 32 and a second radial magnetic ring 33. The first radial magnetic ring 32 and the second radial magnetic ring 33 are coaxially connected to the axial ends of the axial magnetic ring 31 through a mover yoke portion 34 respectively. The magnetic directions of the first radial magnetic ring 32 and the second radial magnetic ring 33 are set to be opposite. The first radial magnetic ring 32 slides axially inside the first stator yoke portion 21, and the second radial magnetic ring 33 slides axially inside the second stator yoke portion 22. A first gap 5 is provided between the inner side wall of the first stator yoke portion 21 and the outer side wall of the first radial magnetic ring 32, and a second gap 6 is provided between the inner side wall of the second stator yoke portion 22 and the outer side wall of the second radial magnetic ring 33. The size h1 of the first gap 5 is smaller than the size h2 of the second gap 6. The magnetic direction of the axial magnetic ring 31 is set to be upward along the axis, the magnetic direction of the first radial magnetic ring 32 is set to be outward along the radius, and the magnetic direction of the second radial magnetic ring 33 is set to be inward along the radius.

[0030] As can be known from the above, by setting the first stator yoke 21, the second stator yoke 22, the axial magnetic ring 31, the rotor yoke 34, the first radial magnetic ring 32 and the second radial magnetic ring 33, the internal magnetic circuit distribution of each component forms a closed magnetic circuit. At the same time, the size of the first gap 5 is smaller than that of the second gap 6. According to the magnetic characteristics of the magnet, the closer the distance between adjacent magnets, the greater the magnetic attraction. The mutual magnetic attraction between the first stator yoke 21 and the first radial magnetic ring 32 is greater than the mutual magnetic attraction between the second stator yoke 22 and the second radial magnetic ring 33. Even if the entire rotor assembly 3 has an axial upward magnetic resistance, thus providing gravity compensation for the self-weight of the rotor assembly 3, improving the thrust and reducing fluctuations. At the same time, this compensation structure can effectively avoid increasing the volume space and manufacturing cost of the motor, realize the miniaturization development of the motor, and reduce the cost. As Figure 7 shown, in other embodiments, the axial magnetic ring 31 includes a plurality of magnet rings connected coaxially.

[0031] Continue to refer to Figure 5 , in this embodiment, the inner side wall of the second stator yoke 22 is arranged as an inclined surface, thereby enabling the size of the first gap 5 to be smaller than that of the second gap 6, ensuring that the rotor assembly 3 has a stable axial upward magnetic resistance and stable gravity compensation. As Figure 6 shown, in other embodiments, the inner side wall of the second stator yoke 22 can be arranged as a stepped surface.

[0032] In this embodiment, a guiding assembly 7 for guiding the movement of the rotor assembly 3 is provided in the motor housing 1. The guiding assembly 7 includes an upper guiding seat 71, an upper guiding ring 72, a lower guiding seat 73 and a lower guiding ring 74. The upper guiding seat 71 is fixedly installed in the motor housing 1 and is located above the first stator yoke 21. The upper guiding ring 72 is slidably arranged on the upper guiding seat 71, and the upper guiding ring 72 is coaxially connected to the first radial magnetic ring 32. The lower guiding seat 73 is fixedly installed in the motor housing 1 and is located below the second stator yoke 22. The lower guiding ring 74 is slidably arranged on the lower guiding seat 73, and the lower guiding ring 74 is coaxially connected to the second radial magnetic ring 33. Thereby, the stable sliding of the first radial magnetic ring 32 and the second radial magnetic ring 33 along the axis can be realized, and the sliding reliability of the rotor assembly 3 is improved.

[0033] In this embodiment, an upper sliding bearing 75 is provided between the upper guiding seat 71 and the upper guiding ring 72, and a lower sliding bearing 76 is provided between the lower guiding seat 73 and the lower guiding ring 74, thereby improving the sliding reliability of the upper guiding ring 72 and the lower guiding ring 74.

[0034] In this embodiment, an encoder 8 and a housing 10 for protecting the encoder 8 are provided on the outer side of the motor housing 1. A coded magnet 9 for the encoder 8 to sense is provided on the upper guide ring 72, whereby the position signal of the mover can be fed back, and the motor control accuracy and response speed can be improved. The encoder 8 is preferably a magnetic encoder 8, and can also be an optoelectronic encoder 8, an inductive encoder 8, a capacitive encoder 8, etc.

[0035] In this embodiment, the motor housing 1 includes a housing 11, a flange cover 12 and an end cover 13. The flange cover 12 is connected to the lower end of the housing 11. A through hole 121 for the output shaft 4 to pass through is provided on the flange cover 12. A bearing slidably engaged with the output shaft 4 is provided in the through hole 121. The end cover 13 is connected to the upper end of the housing 11. The encoder 8 and the housing 10 are installed on the outer side of the end cover 13, whereby the assembly of the motor can be facilitated and the output reliability of the output shaft 4 can be improved at the same time.

[0036] In this embodiment, the stator assembly 2 further includes a first winding coil 23, a second winding coil 24 and a coil skeleton 25. The first winding coil 23 is disposed on the inner side wall of the first stator yoke 21 through the coil skeleton 25. The second winding coil 24 is disposed on the inner side wall of the second stator yoke 22 through the coil skeleton 25. The first winding coil 23 and the second winding coil 24 are axially spaced apart, whereby the moving output of the output shaft 4 can be realized.

[0037] In this embodiment, the first winding coil 23 and the second winding coil 24 are potted in the coil skeleton 25 with potting resin glue, whereby the fixation and heat dissipation of the winding coils can be realized.

[0038] As Figure 8 shown, in other embodiments, the mover assembly 3 includes a plurality of axial magnetic rings 31, a plurality of first radial magnetic rings 32 and a plurality of second radial magnetic rings 33, and they are axially spaced apart from each other.

[0039] In the description of the embodiments of the present application, it should be noted that in the description of the present application, the terms indicating the direction or positional relationship such as "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description, rather than indicating or implying that the device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present application.

[0040] In the description of the present application, the descriptions referring to terms such as "one embodiment", "some embodiments", "in this embodiment", "specific examples", or "some examples", etc. mean that the specific features, mechanisms, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0041] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A voice coil motor, comprising a motor housing (1), a stator assembly (2) and a mover assembly (3) installed in the motor housing (1). An output shaft (4) is connected to the mover assembly (3), and one end of the output shaft (4) away from the mover assembly (3) extends out of the motor housing (1). It is characterized in that: The stator assembly (2) includes a first stator yoke portion (21) and a second stator yoke portion (22). The first stator yoke portion (21) and the second stator yoke portion (22) are coaxially and integrally connected, and the first stator yoke portion (21) is located above the second stator yoke portion (22). Both the first stator yoke portion (21) and the second stator yoke portion (22) are in a ring structure. The mover assembly (3) includes an axial magnetic ring (31), a first radial magnetic ring (32) and a second radial magnetic ring (33). The first radial magnetic ring (32) and the second radial magnetic ring (33) are coaxially connected to the axial magnetic ring (31) at both axial ends through a mover yoke portion (34). The magnetic directions of the first radial magnetic ring (32) and the second radial magnetic ring (33) are set in opposite directions. The first radial magnetic ring (32) is slidably arranged along the axis inside the first stator yoke portion (21), and the second radial magnetic ring (33) is slidably arranged along the axis inside the second stator yoke portion (22). A first gap (5) is provided between the inner side wall of the first stator yoke portion (21) and the outer side wall of the first radial magnetic ring (32), and a second gap (6) is provided between the inner side wall of the second stator yoke portion (22) and the outer side wall of the second radial magnetic ring (33). The size of the first gap (5) is smaller than the size of the second gap (6).

2. The voice coil motor according to claim 1, characterized in that, The inner diameters of the first stator yoke portion (21) are the same. The inner diameter of the second stator yoke portion (22) gradually increases from top to bottom, and the inner diameter of the second stator yoke portion (22) is larger than the inner diameter of the first stator yoke portion (21). The outer diameters of the first radial magnetic ring (32) and the second radial magnetic ring (33) are the same.

3. The voice coil motor according to claim 2, wherein, The inner side wall of the second stator yoke portion (22) is arranged as an inclined surface.

4. The voice coil motor according to claim 2, wherein, The inner side wall of the second stator yoke portion (22) is arranged as a stepped surface.

5. The voice coil motor according to claim 1, characterized in that A guiding assembly (7) for guiding the movement of the mover assembly (3) is provided in the motor housing (1). The guiding assembly (7) includes an upper guiding seat (71), an upper guiding ring (72), a lower guiding seat (73) and a lower guiding ring (74). The upper guiding seat (71) is fixedly installed in the motor housing (1) and is located above the first stator yoke portion (21). The upper guiding ring (72) is slidably arranged on the upper guiding seat (71), and the upper guiding ring (72) is coaxially connected to the first radial magnetic ring (32). The lower guiding seat (73) is fixedly installed in the motor housing (1) and is located below the second stator yoke portion (22). The lower guiding ring (74) is slidably arranged on the lower guiding seat (73), and the lower guiding ring (74) is coaxially connected to the second radial magnetic ring (33).

6. The voice coil motor according to claim 5, characterized in that An upper sliding bearing (75) is provided between the upper guide seat (71) and the upper guide ring (72), and a lower sliding bearing (76) is provided between the lower guide seat (73) and the lower guide ring (74).

7. The voice coil motor according to claim 5, characterized in that, An encoder (8) and a housing (10) for protecting the encoder (8) are provided on the outer side of the motor housing (1), and an encoding magnet (9) for the encoder (8) to sense is provided on the upper guide ring (72).

8. The voice coil motor according to claim 7, characterized in that, The motor housing (1) includes a housing (11), a flange cover (12) and an end cover (13). The flange cover (12) is connected to the lower end of the housing (1). A through hole (121) for the output shaft (4) to pass through is provided on the flange cover (12). A bearing that is slidably matched with the output shaft (4) is provided in the through hole (121). The end cover (13) is connected to the upper end of the housing (1), and the encoder (8) and the housing (10) are installed on the outer side of the end cover (13).

9. The voice coil motor according to claim 1, characterized in that, The stator assembly (2) further includes a first winding coil (23), a second winding coil (24) and a coil skeleton (25). The first winding coil (23) is arranged on the inner side wall of the first stator yoke portion (21) through the coil skeleton (25). The second winding coil (24) is arranged on the inner side wall of the second stator yoke portion (22) through the coil skeleton (25). The first winding coil (23) and the second winding coil (24) are arranged at an axial interval.

10. The voice coil motor according to claim 9, characterized in that, The first winding coil (23) and the second winding coil (24) are potted in the coil skeleton (25) with potting resin glue.

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