Micro motor structure

Abstract

A micro motor structure comprises a shell, an output shaft, a rotor assembly and a stator assembly, the output shaft is arranged in the shell, the rotor assembly comprises a rotor frame and a magnet set fixedly arranged on the rotor frame, the rotor frame comprises a rotor part, an elastic part and an end cover part which are integrally formed, and the rotor part and the output shaft are connected and can rotate synchronously; the elastic part is connected between the rotor part and the end cover part and can be twisted and deformed, and the end cover part is connected with the shell in an involution manner; the magnet group is fixedly arranged on the rotor part and can synchronously rotate; the stator assembly is fixedly arranged in the shell and surrounds the rotor part. The rotor frame structure is integrally formed, can replace a rotor iron core, a spring and an end cover in an existing structure, is simple in structure, beneficial to processing, capable of simplifying assembling difficulty and reducing part cost, lighter in structure, higher in modeling performance, lower in noise, resistant to corrosion and capable of prolonging the service life. The micro motor structure of the utility model has strong practicability and is suitable for vigorous popularization.

Description

Technical Field

[0001] The utility model relates to the field of micro motors, and particularly to a structure of a micro motor. Background Art

[0002] A micro motor generally includes a stator assembly, a rotor assembly and an output shaft. Among them, the rotor assembly usually includes a plurality of magnets and a rotor core, and the stator assembly usually includes a stator core and a coil. The magnet, the rotor core and the output shaft are usually connected together and rotate as a whole; while the stator assembly is fixedly arranged in a housing.

[0003] The rotor core is an important component in the motor, which is usually made of magnetic materials. In the existing such micro motors, the stator core and the rotor core are usually formed by laminating a plurality of silicon steel sheets or silicon steel sheets, because the silicon steel sheets and silicon steel sheets have high magnetic permeability, which can conduct magnetic fields and ensure the conversion of electromagnetic energy.

[0004] Generally, for motors with different structures, those skilled in the art will select different magnetic materials to make the rotor core or the stator core, and will not select plastic materials as the main material of the rotor core, because plastic does not have the necessary magnetic properties.

[0005] In addition, for this kind of micro motor, in order to assist the rotor to return to the correct position, a spring is usually arranged at one end of the output shaft, and the restoring force is provided by the torsional deformation of the spring to assist the rotor to return to the correct position. However, since the rotor core is usually made of magnetic materials, the spring and the core rotor are usually independent components, and assembly is required between the two. This will increase the complexity of the process assembly to a certain extent and increase the part cost. Summary of the Utility Model

[0006] The utility model aims to solve the above problems, and provides a micro motor structure which is easy to assemble, can reduce costs, can reduce noise and improve product performance.

[0007] To solve the above problems, the utility model provides a micro motor structure, which is characterized in that it includes:

[0008] A housing, provided with an accommodation cavity;

[0009] An output shaft, arranged in the housing, and at least one end extends out of the housing to form an output end;

[0010] A rotor assembly, including a rotor frame and a magnet group fixedly arranged on the rotor frame, the rotor frame includes a rotor part, an elastic part and an end cover part which are integrally formed, the rotor part is connected to the output shaft and can rotate synchronously, the elastic part is connected between the rotor part and the end cover part and can be torsionally deformed, and the end cover part is connected to the housing in a mating manner; the magnet group is fixedly arranged on the rotor part and can rotate synchronously;

[0011] The stator assembly is fixedly arranged in the housing and surrounds the rotor part outside.

[0012] Furthermore, the rotor frame is made of plastic material.

[0013] Furthermore, the rotor part is in a long column shape. On the end face of the rotor part, there are slots extending along its axial direction. At the bottom of the slots, there are positioning grooves. A stepped structure is formed between the slots and the positioning grooves. One end of the output shaft opposite to the output end is inserted into the slots and cooperates with the positioning grooves to be connected together in a non-rotatable manner.

[0014] Furthermore, on the side wall of the rotor part, there are several magnet grooves extending along its axial direction. The magnet group includes several magnets, and the magnets are respectively embedded in the magnet grooves.

[0015] Furthermore, the elastic part includes several unit parts. One ends of the unit parts are integrally connected, and the other ends of the unit parts are distributed at intervals.

[0016] Furthermore, the number of the unit parts is the same as the number of the magnet grooves, and the projections of the unit parts on the rotor part respectively partially coincide with the magnet grooves.

[0017] Furthermore, the housing is in a cylindrical shape, with one end open and the other end provided with a bearing hole; the end cover part is connected to the open end of the housing in a non-rotatable manner; a bearing is arranged in the bearing hole, and the bearing sleeves the non-end part of the output shaft.

[0018] Furthermore, the stator assembly includes:

[0019] A stator frame, fixedly arranged in the housing and surrounding the rotor part outside;

[0020] Coils, fixedly arranged on the stator frame;

[0021] A stator iron core, fixedly arranged on the stator frame;

[0022] When the coils are energized with the working power supply, virtual magnetic poles with alternating magnetic poles are generated on the stator iron core and interact with the magnet group to drive the rotor assembly to reciprocally rotate around the central axis of the output shaft, thereby driving the output shaft to reciprocally rotate at a high frequency.

[0023] Further, the stator frame includes an integrally formed cylindrical part, a connecting part, and a supporting part. The supporting parts are symmetrically arranged outside the cylindrical part and are spaced apart from the cylindrical part. The connecting part is connected between the cylindrical part and the supporting parts. The cylindrical part is cylindrical, and an enclosing cavity is formed inside it. The inside of the connecting part is hollow and penetrates through the enclosing cavity and the supporting parts.

[0024] Further, the coils are respectively sleeved on the connecting parts, and the stator core is inserted on the supporting parts and inside the connecting parts.

[0025] Further, the stator core includes a positioning part and a magnetic shoe part. The positioning part is fitted on the supporting part, and the magnetic shoe part passes through the supporting part and is inserted into the connecting part. The end of the magnetic shoe part faces the middle position between two adjacent magnet slots.

[0026] The beneficial contribution of the present utility model is that it effectively solves the above problems. The rotor assembly of the present utility model includes a rotor frame and a magnet group. The rotor frame includes an integrally formed rotor part, an elastic part, and an end cover part. Its structure is integrally formed, which can replace the rotor core, spring, and end cover in the existing structure. It not only has a simple structure, is conducive to processing, can simplify the assembly difficulty, and reduce the part cost, but also has a lighter structure, stronger moldability, lower noise, and can be corrosion-resistant to improve the service life. The micro-motor structure of the present utility model has the characteristics of simple structure and easy implementation. It has strong practicability and is suitable for extensive promotion. Description of the Drawings

[0027] Figure 1 is the longitudinal sectional view of the present utility model.

[0028] Figure 2 is the transverse sectional view of the present utility model.

[0029] Figure 3 is the structural exploded view of the present utility model.

[0030] Figure 4 is the structural view of the rotor frame.

[0031] Figure 5 is the structural view of the stator frame.

[0032] Figure 6 is the transverse sectional view of the rotor frame.

[0033] Reference Signs in the Drawings:

[0034] Housing 10: Accommodating cavity 11;

[0035] Output shaft 20: Output end 21;

[0036] Rotor assembly 30: rotor frame 31, rotor part 311, slot 3111, positioning groove 3112, magnet groove 3113, elastic part 312, unit part 3121, end cover part 313, deep groove 3131, support protrusion 3132, magnet group 32;

[0037] Stator assembly 40: stator frame 41, cylindrical body part 411, connecting part 412, support part 413, enclosing cavity 414, coil 42, stator iron core 43, positioning part 431, magnetic shoe part 432;

[0038] Bearing 50. Detailed implementation mode

[0039] The following embodiments are further explanations and supplements to the present utility model, and do not constitute any limitation to the present utility model.

[0040] As Figures 1 to 6 shown, the micro-motor structure of the present utility model includes a housing 10, an output shaft 20, a rotor assembly 30 and a stator assembly 40. The housing 10 is provided with a receiving cavity 11 for receiving the rotor assembly 30 and the stator assembly 40. The output shaft 20 is disposed in the housing 10, and at least one end of the output shaft 20 extends out of the housing 10 to form an output end 21 for outputting high-frequency vibration outward to drive a corresponding article to vibrate, such as a toothbrush head. The stator assembly 40 is fixedly disposed in the housing 10 and surrounds the rotor assembly 30. The rotor assembly 30 includes a rotor frame 31 and a magnet group 32 fixedly disposed on the rotor frame 31.

[0041] The main point of the present utility model is that, as Figure 1 , Figure 3 , Figure 4 shown, the rotor frame 31 includes an integrally formed rotor part 311, an elastic part 312 and an end cover part 313, and its structure is integrally formed, rather than a split structure of a rotor iron core, a spring and an end cover. The structure of the present utility model is simple, which can greatly reduce the assembly difficulty and cost without affecting the electromagnetic performance.

[0042] The rotor part 311 is connected to the output shaft 20 and can rotate synchronously. The elastic part 312 is connected between the rotor part 311 and the end cover part 313. The elastic part 312 can be torsionally deformed and has an elastic deformation ability. It can provide a restoring force for the rotation of the rotor part 311 when the rotor part 311 reciprocates to rotate, so as to assist the rotor part 311 and the output shaft 20 to return to the correct position. The end cover part 313 is connected to the housing 10 in a mating manner and cannot rotate. It is used to fix one end of the elastic part 312, and the other end can rotate with the rotor part 311.

[0043] The magnet group 32 is fixedly arranged on the rotor part 311 and can rotate synchronously.

[0044] During operation, the rotor part 311, the magnet group 32, and the output shaft 20 rotate reciprocally as a whole. During the rotation process, since one end of the elastic part 312 is fixed and the other end is integrally connected to the rotor part 311, the elastic part 312 is torsionally deformed to accumulate elastic force, and it has a tendency to reset, so it can be used to assist the rotor part 311 to return to the correct position.

[0045] Furthermore, the entire rotor frame 31 is made of plastic material. Compared with silicon steel sheets, silicon steel sheets, and metal springs, it not only has a light weight, but also has a low cost and stronger structural plasticity. In addition, silicon steel sheets and silicon steel sheets are prone to corrosion, and the plastic-made rotor frame 31 can greatly improve the corrosion resistance, thereby increasing the product life. On the other hand, the rotor part 311, the elastic part 312, and the end cover part 313 are integrally formed, which can reduce the noise between the mating parts. Moreover, the rotor part 311, the elastic part 312, and the end cover part 313 are made of plastic material, and plastic has a certain sound absorption ability, which can also greatly reduce the motor noise. Therefore, the motor structure of the present utility model can also reduce noise.

[0046] Furthermore, the rotor part 311, the elastic part 312, and the end cover part 313 of the rotor frame 31 are integrally formed of the same material, but due to the different shapes of the structures of each part, they have different characteristics. Among them, the rotor part 311 is a hard structure or a relatively hard structure as a whole, and the rotor part 311 can rotate reciprocally as a whole, and the rotor part 311 itself does not deform during the rotation process. The elastic part 312 has a certain length in the axial direction, so it is not prone to deformation in the axial direction, but can be torsionally deformed in the circumferential direction. The end cover part 313 is a hard structure or a relatively hard structure. When the elastic part 312 is torsionally deformed, the position of the end cover part 313 does not change, and the end cover part 313 itself does not deform.

[0047] Furthermore, as Figure 4As shown, the rotor part 311 is in a long column shape. To connect with the output shaft 20, a slot 3111 extending along its axial direction is provided on the end face of the rotor part 311. The slot 3111 cooperates with the output shaft 20, and the fit between them can be an interference fit or a clearance fit. Preferably, the fit between the slot 3111 and the output shaft 20 is an interference fit. To prevent the output shaft 20 from rotating relative to the rotor frame 31, a positioning groove 3112 is provided at the bottom of the slot 3111. A stepped structure is formed between the positioning groove 3112 and the slot 3111, and the positioning groove 3112 is a non-circular groove, which has the function of preventing circumferential rotation. One end of the output shaft 20 opposite to the output end 21 is inserted into the slot 3111 and is in shape fit with the positioning groove 3112. In this way, the output shaft 20 and the rotor part 311 are connected together in a rotation-resistant manner, and the two can rotate together without relative rotation.

[0048] To install magnets, as Figure 3 , Figure 4 shown, a plurality of magnet grooves 3113 extending along its axial direction are provided on the side wall of the rotor part 311. The magnet grooves 3113 are long strip-shaped grooves. In this embodiment, a total of 4 magnet grooves 3113 are provided at intervals, and each magnet groove 3113 extends from one end of the rotor part 311 to the other end along the axial direction, thus forming a through groove structure. The shape of the magnet groove 3113 is not limited, and it is preferably a rectangular groove, which can be used to install rectangular strip magnets.

[0049] The magnet grooves 3113 are symmetrically arranged. They are symmetric not only with respect to the symmetry axis L1 but also with respect to the symmetry axis L2, and L1 and L2 are perpendicular to each other and perpendicular to the axial direction of the output shaft 20 through the axis of the output shaft 20.

[0050] Furthermore, as Figure 6 shown, the elastic part 312 includes a plurality of unit parts 3121, and the shapes of the unit parts 3121 can be the same or different. One end of the unit part 3121 is integrally connected, and the other ends are distributed at intervals. In this way, it is beneficial to improve the strength of the elastic part 312.

[0051] Further, the number of the unit parts 3121 is the same as the number of the magnet grooves 3113. There are 4 unit parts 3121 in total for the elastic part 312, and the positions of the unit parts 3121 correspond to the distribution positions of the magnet grooves 3113. Specifically, the projections of the unit parts 3121 on the rotor part 311 respectively partially coincide with the magnet grooves 3113. In this way, the angle between the unit parts 3121 can be made the same as or substantially the same as the angle between the magnet grooves 3113 (the angle between the connecting lines of the central positions of the magnet grooves 3113 and the center of the output shaft 20) and the angle of the reciprocating rotation of the output shaft 20. In this way, the strength of the elastic part 312 is more conducive to torsional deformation for promoting the elastic part 312 to return to the original position.

[0052] Further, the housing 10 is in a cylindrical shape, with one end open and the other end provided with a bearing hole. A bearing 50 is installed in the bearing hole, and the bearing 50 is sleeved on the non-end part of the output shaft 20. The bearing 50 is conducive to the rotation of the output shaft 20.

[0053] The cross-sectional shape of the housing 10 is not limited. In this embodiment, it is in a runway shape. The shape of the end cover part 313 matches the shape of the open end of the housing 10, and the two can be mated to be connected together in a non-rotatable manner.

[0054] For the convenience of mating the end cover part 313 with the housing 10, mating steps are respectively provided at the mating parts of the housing 10 and the end cover part 313. Through the mating of the mating steps, the housing 10 and the end cover part 313 can be mated and connected together by mutual abutment.

[0055] Further, a concave deep groove 3131 is formed on the end cover part 313. One end of the elastic part 312 is integrally connected to the bottom of the deep groove 3131, and the outer wall of the elastic part 312 is spaced from the side wall of the deep groove 3131. The other end of the elastic part 312 extends out of the deep groove 3131 and is integrally connected to the rotor part 311 outside the deep groove 3131.

[0056] For the convenience of leading the wires of the coil 42, lead holes are respectively provided on the end cover part 313 and / or the housing 10. The shape and number of the lead holes can be set according to needs.

[0057] Further, in order to support the stator assembly 40, a support protrusion 3132 is provided on the inner side of the end cover part 313. The support protrusion 3132 is arranged on the periphery of the deep groove 3131, and protrudes from the end cover part 313, and it can support the stator assembly 40.

[0058] The stator assembly 40 includes a stator frame 41, a coil 42 and a stator core 43.

[0059] The stator frame 41 is fixedly arranged in the housing 10 and surrounds the rotor part 311. The coil 42 is fixedly arranged on the stator frame 41, and the stator core 43 is fixedly arranged on the stator frame 41. When the coil 42 is powered on, virtual magnetic poles with alternating magnetic poles are generated on the stator core 43, which interact with the magnet group 32 to drive the rotor assembly 30 to reciprocally rotate around the central axis of the output shaft 20, thereby driving the output shaft 20 to rotate at a high frequency reciprocally.

[0060] Further, the stator frame 41 includes an integrally formed cylindrical part 411, a connecting part 412, and a supporting part 413.

[0061] The cylindrical part 411 is cylindrical, and an enclosing cavity 414 is formed inside it. The rotor part 311 of the rotor frame 31 is located in the enclosing cavity 414 and is spaced from the inner wall of the cylindrical part 411. The elastic part 312 is partially located inside the enclosing cavity 414 and partially extends outside the enclosing cavity 414. The end cover part 313 is located outside the enclosing cavity 414. The shape of the cylindrical part 411 is not limited. In this embodiment, the cross-section of the cylindrical part 411 is rectangular or quasi-rectangular, and the enclosing cavity 414 is in a racetrack shape. Among its four side walls, two opposite side walls are flat, and two opposite side walls are arc-shaped.

[0062] By surrounding the rotor part 311 and the magnet group 32 with the cylindrical part 411, the magnet group 32 can interact better with the stator core 43.

[0063] The supporting parts 413 are symmetrically arranged outside the cylindrical part 411 and are spaced from the cylindrical part 411. The supporting parts 413 are used to arrange the stator core 43.

[0064] The connecting part 412 is connected between the cylindrical part 411 and the supporting part 413, thereby forming a winding space around which the coil 42 can be wound between the supporting part 413 and the cylindrical part 411. The coil 42 is respectively sleeved on the connecting part 412, and its two sides are restricted by the cylindrical part 411 and the supporting part 413, so the coil 42 is not easily loosened. And through the connecting part 412, the coil 42 can be isolated from the stator core 43.

[0065] The inside of the connecting part 412 is hollow and penetrates the enclosing cavity 414 and the supporting part 413. In this way, the stator core 43 can be inserted from one side of the supporting part 413, and the stator core 43 passes through the connecting part 412 and faces the rotor frame 31.

[0066] The stator core 43 includes a positioning portion 431 and a magnetic shoe portion 432. The positioning portion 431 is in the shape of an arc plate, one side of which opposite to the magnetic shoe portion 432 is arc-shaped, and one side of which connected to the magnetic shoe portion 432 is flat. The magnetic shoe portion 432 is in the shape of a rectangular block, which protrudes from the middle position of the positioning portion 431, so that the stator core 43 is in a T-shaped structure.

[0067] The positioning portion 431 is fitted on the support portion 413, and the magnetic shoe portion 432 passes through the support portion 413 and is inserted into the connection portion 412. The end of the magnetic shoe portion 432 faces the rotor frame 31 and is located at the middle position between two adjacent magnet slots 3113.

[0068] In the present utility model, two stator cores 43 are symmetrically provided, and they are both formed by laminating silicon steel sheets. The stator frame 41 is made of plastic material. The housing 10 is made of plastic material. The output shaft 20 is a metal shaft.

[0069] The whole stator assembly 40 is fixedly arranged in the housing 10. The connection between them can be interference fit, or can be glued, or a combination of various fixing means. In this embodiment, the two sides of the cylindrical portion 411 without the connection portion 412 are respectively in contact with the inner wall of the housing 10, so that the cylindrical portion 411 is tightly fitted in the housing 10 and remains stationary. On this basis, in order to avoid structural looseness, an adhesive can be applied between the cylindrical portion 411 and the housing 10 for bonding.

[0070] In addition, after the support portion 413 and the positioning portion 431 are fitted, their outer sides are in contact with the inner wall of the housing 10, so that the support portion 413 and the positioning portion 431 are tightly fitted in the housing 10 and remain stationary.

[0071] Thus, the whole stator assembly 40 can be fixedly arranged in the housing 10.

[0072] When the coil 42 is energized with the working power supply, virtual magnetic poles will be generated on the positioning portion 431. By controlling the power supply, virtual magnetic poles with alternating magnetic poles can be generated on the positioning portion 431. In this way, it can interact with the magnet group 32. Under the action of like poles attracting and unlike poles repelling, the rotor portion 311 and the magnet group 32 are driven to rotate reciprocally, thereby driving the output shaft 20 to rotate reciprocally at a high frequency. When the rotor portion 311 and the magnet group 32 rotate reciprocally, they rotate around a fixed axis, and this fixed axis coincides with the central axis of the output shaft 20. When the rotor portion 311, the magnet group 32 and the output shaft 20 rotate reciprocally, the elastic portion 312 is torsionally deformed, so as to have a tendency to drive the rotor portion 311 to return to the normal position, and it can assist the rotor portion 311 and the output shaft 20 to return to the normal position.

[0073] Although the present utility model has been disclosed through the above embodiments, the scope of the present utility model is not limited thereto. Under the condition of not deviating from the concept of the present utility model, the above components can be replaced by similar or equivalent elements understood by those skilled in the art.

Claims

1. A micro motor structure, characterized in that: It includes: The housing (10) is provided with a receiving cavity (11); An output shaft (20) is disposed in the housing (10), with at least one end extending out of the housing (10) to form an output end (21); A rotor assembly (30) comprising a rotor frame (31) and a magnet group (32) fixedly mounted on the rotor frame (31); the rotor frame (31) comprising an integrally formed rotor portion (311), an elastic portion (312) and an end cover portion (313); the rotor portion (311) is connected to the output shaft (20) and can rotate synchronously; the elastic portion (312) is connected between the rotor portion (311) and the end cover portion (313) and can be torsionally deformed; the end cover portion (313) is mateably connected to the housing (10); the magnet group (32) is fixedly mounted on the rotor portion (311) and can rotate synchronously; The stator assembly (40) is fixedly disposed in the housing (10) and surrounds the rotor part (311).

2. The micromotor structure according to claim 1, characterized in that: The rotor frame (31) is made of plastic material.

3. The micro motor structure according to claim 2, characterized in that: The rotor part (311) is in the shape of a long column, and a slot (3111) extending along the axial direction thereof is provided on the end surface of the rotor part (311), and a positioning slot (3112) is provided at the bottom of the slot (3111), and a step structure is formed between the slot (3111) and the positioning slot (3112), and an end of the output shaft (20) opposite to the output end (21) is inserted into the slot (3111) and cooperates with the positioning slot (3112) to be connected together in a rotationally resistant manner.

4. The micromotor structure according to any one of claims 1 to 3, characterized in that: A plurality of magnet slots (3113) extending along the axial direction of the rotor part (311) are provided on the side wall of the rotor part (311), and the magnet group (32) comprises a plurality of magnets, which are respectively embedded in the magnet slots (3113).

5. The micro motor structure according to claim 4, characterized in that: The elastic portion (312) comprises a plurality of unit portions (3121), one end of the unit portions (3121) being integrally connected, and the other end of the unit portions (3121) being distributed at intervals.

6. The micro motor structure according to claim 5, characterized in that: The number of the unit parts (3121) is consistent with the number of the magnet slots (3113), and the projections of the unit parts (3121) on the rotor part (311) respectively overlap with parts of the magnet slots (3113).

7. The micro motor structure according to claim 6, characterized in that: The housing (10) is cylindrical, one end of which is open and the other end of which is provided with a bearing hole. The end cover portion (313) is matched with the open end of the housing (10) and connected together in a rotationally-resistant manner; A bearing (50) is provided in the bearing hole, and the bearing (50) is sleeved on the non-end portion of the output shaft (20).

8. The micro motor structure according to claim 1 or 2, characterized in that: The stator assembly (40) comprises: A stator frame (41) is fixedly disposed in the housing (10) and surrounds the rotor portion (311); A coil (42) fixedly mounted on the stator frame (41); A stator iron core (43) fixedly mounted on the stator frame (41); When the coil (42) is supplied with working power, virtual magnetic poles with alternating magnetic poles are generated on the stator core (43) and interact with the magnet group (32) to drive the rotor assembly (30) to reciprocate around the central axis of the output shaft (20), thereby driving the output shaft (20) to reciprocate at high frequency.

9. The micro motor structure according to claim 8, characterized in that: The stator frame (41) comprises an integrally formed cylindrical portion (411), a connecting portion (412) and a supporting portion (413); the supporting portion (413) is symmetrically arranged outside the cylindrical portion (411) and spaced apart from the cylindrical portion (411); and the connecting portion (412) is connected between the cylindrical portion (411) and the supporting portion (413); The cylindrical body (411) is cylindrical in shape, and an enclosed cavity (414) is formed inside the cylindrical body; The connecting portion (412) is hollow inside and passes through the enclosed cavity (414) and the supporting portion (413); The coils (42) are respectively sleeved on the connecting parts (412), and the stator core (43) is inserted on the supporting part (413) and inside the connecting part (412).

10. The micro motor structure according to claim 9, characterized in that: The stator core (43) comprises a positioning portion (431) and a magnetic shoe portion (432), wherein the positioning portion (431) is fitted on the support portion (413), the magnetic shoe portion (432) passes through the support portion (413) and is inserted into the connecting portion (412), and the end of the magnetic shoe portion (432) faces the middle position of two adjacent magnet slots (3113).

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