Outer rotor iron shell of brushless motor
By designing a raised structure on the iron shell of the brushless motor outer rotor and using stamping forming process, the dynamic balance and noise problems caused by internal stress are solved, and more efficient production and performance improvement are achieved.
Patent Information
- Application Number
- CN202420948840.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-28
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-04-28
AI Technical Summary
During the production and processing of existing brushless motor outer rotor iron shells, the internal stress caused by material tensile, resulting in dynamic balance and noise problems. The existing solutions can be adjusted through grinding, but it will damage the plating, increase costs and reduce production speed.
A cylindrical outer rotor iron shell is designed with a uniformly arranged on the bottom of the cylinder, and internal stress is released through the stamping molding process to ensure that dynamic balance and noise are controlled within the appropriate range.
Through stamping and forming of the raised structure, the dynamic balance is effectively controlled at <25 mg and the noise is <25 dBA, which improves the performance of the brushless motor, ensures stable mass production and reduces costs.
Smart Images
Figure CN222301525U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of brushless motors, in particular to an outer rotor iron shell of a brushless motor. Background Art
[0002] During the production and processing of the conventional brushless motor outer rotor iron shell, internal stress will be generated at the bottom of the outer rotor iron shell due to multiple stretching of the material. Under the influence of stress, after the center shaft is pressed into the center hole of the outer rotor iron shell, the concentricity and verticality are usually greater than 0.03mm, which will cause the dynamic balance to be greater than 40mg. In this case, the noise generated during the high-speed operation of the motor is greater than 40dBA. At present, in order to solve the dynamic balance and noise problems, the outer rotor iron shell is ground to adjust the dynamic balance to less than 25mg, so as to achieve the control of noise less than 25dBA. Since the outer rotor iron shell needs to be ground to adjust the dynamic balance, the surface coating of the outer rotor iron shell will be damaged after grinding. After the coating is damaged, it is easier to rust, which will affect the life of the motor. Moreover, using grinding to solve the dynamic balance and noise problems seriously reduces the production speed and increases the cost. Utility Model Content
[0003] Based on this, the utility model provides an outer rotor iron shell of a brushless motor to solve the above series of problems caused by the need to use a lossy method to adjust the dynamic balance of the outer rotor iron shell of the existing brushless motor.
[0004] To achieve the above-mentioned purpose, the utility model provides an outer rotor iron shell of a brushless motor, wherein the outer rotor iron shell is an integrally formed cylindrical tube structure, and a mounting hole for mounting a central axis is provided at the center of the bottom of the outer rotor iron shell. The utility model is characterized in that at least one circle of raised structures is evenly arranged around the mounting hole on the bottom of the outer rotor iron shell, and the raised structure is formed by a depression on one side of the bottom of the outer rotor iron shell and a corresponding projection on the other side.
[0005] As a further preferred technical solution of the present utility model, the protrusion structure is in a circular ring shape on the bottom of the outer rotor iron shell and is concentric with the mounting hole.
[0006] As a further preferred technical solution of the present utility model, the protrusion structure is an arc-shaped protrusion, and an arc transition is adopted between the protrusion structure and the bottom plane of the outer rotor iron shell.
[0007] As a further preferred technical solution of the present utility model, the protrusion height of the protrusion structure relative to the bottom plane of the outer rotor iron shell is 0.3-5mm.
[0008] As a further preferred technical solution of the present utility model, the protrusion height of the protrusion structure relative to the bottom plane of the outer rotor iron shell is 1 mm.
[0009] As a further preferred technical solution of the utility model, a circular boss is provided at the center of the bottom of the outer rotor iron shell, which is recessed on one side and correspondingly convex on the other side. The top surface of the circular boss is a plane, and the mounting hole is provided at the center of the top surface of the circular boss.
[0010] As a further preferred technical solution of the present invention, the wall thickness tolerance of the outer rotor iron shell is less than 0.015 mm.
[0011] As a further preferred technical solution of the present invention, the surface of the outer rotor iron shell is smooth and free of burrs.
[0012] Compared with the prior art, the brushless motor outer rotor iron shell of the utility model can achieve the following beneficial effects:
[0013] Before the optimization, the outer rotor iron shell had low mass production capacity, high cost, and insufficient supply to the market. After the optimization of the utility model, a circle of raised structures is pressed on the bottom of the outer rotor iron shell, and the raised structures can be formed by stamping. During the process of forming the raised structures, the material can be effectively released after being pulled, so that the dynamic balance can be controlled to less than 25 mg, and the noise generated during the high-speed operation of the motor can be controlled to less than 25dBA. This ensures that while improving the performance of the brushless motor, it can ensure the stability of mass production, ensure the supply market demand, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0015] Figure 1 It is a schematic diagram of the bottom structure of the brushless motor outer rotor iron shell;
[0016] Figure 2 It is a side perspective view of the outer rotor iron shell of the brushless motor;
[0017] Figure 3 for Figure 2 An enlarged view of part A of the outer rotor iron shell of the brushless motor.
[0018] In the figure: 1. raised structure, 2. circular boss, 3. mounting hole, 4. center axis.
[0019] The purpose, features and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. The terms such as "upper", "lower", "left", "right", "middle" and "one" used in the preferred embodiments are only used to facilitate the description, and are not used to limit the scope of the implementation of the present invention. The changes or adjustments in their relative relationships shall also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.
[0021] like Figure 1-Figure 3 As shown, the utility model provides an outer rotor iron shell of a brushless motor, wherein the outer rotor iron shell is an integrally formed cylindrical tube structure, the wall thickness tolerance of which is less than 0.015 mm, and the surface is smooth and free of burrs.
[0022] The center of the bottom of the outer rotor iron shell is provided with a mounting hole 3 for mounting the central axis 4. A circle of protrusion structures 1 with a protrusion height of 1 mm is evenly arranged around the mounting hole 3 on the bottom of the outer rotor iron shell. The protrusion structure 1 is in a circular ring shape on the bottom of the outer rotor iron shell and is concentric with the mounting hole 3. The protrusion structure 1 is formed by a depression on one side of the bottom of the outer rotor iron shell and a corresponding protrusion on the other side. The protrusion structure 1 is formed by stamping, and the forming process is simple. In addition, during the process of forming the protrusion structure 1, the material can effectively release the internal stress after being pulled, so that the dynamic balance can be controlled at <25 mg, and the noise generated during the high-speed operation of the motor is controlled at <25 dBA.
[0023] Preferably, the protrusion structure 1 is an arc-shaped protrusion, and an arc transition is adopted between the protrusion structure 1 and the bottom plane of the outer rotor iron shell. The arc structure and arc transition are adopted, so that the protrusion structure 1 is formed more evenly, thereby ensuring better dynamic balance.
[0024] In a specific embodiment, a circular boss 2 is provided at the center of the bottom of the outer rotor iron shell, which is concave on one side and convex on the other side, the top surface of the circular boss 2 is a plane, and the mounting hole 3 is provided at the center of the top surface of the circular boss 2. Preferably, the convex direction of the circular boss 2 faces the inner side of the outer rotor iron shell.
[0025] Only when the verticality and concentricity of brushless motor products are done well can the balance be guaranteed. The smaller the balance, the lower the noise and the better the motor performance. The top of the circular boss 2 is designed with a flat process, which can be used as a reference for measurement and verification, which not only facilitates data testing, but also can accurately judge the quality of product performance.
[0026] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.
Claims
1. A brushless motor outer rotor iron shell, the outer rotor iron shell is an integrally formed cylindrical tube structure, the outer rotor iron shell has a mounting hole for mounting a central axis at the center of the tube bottom, characterized in that: At least one circle of raised structures is evenly arranged on the bottom of the outer rotor iron shell around the mounting hole, and the raised structures are formed by a depression on one side of the bottom of the outer rotor iron shell and a corresponding projection on the other side.
2. The brushless motor outer rotor iron shell according to claim 1, characterized in that: The protrusion structure is in a circular ring shape on the bottom of the outer rotor iron shell and is concentric with the mounting hole.
3. The brushless motor outer rotor iron shell according to claim 1, characterized in that: The protrusion structure is an arc-shaped protrusion, and an arc transition is adopted between the protrusion structure and the cylinder bottom plane of the outer rotor iron shell.
4. The brushless motor outer rotor iron shell according to claim 1, characterized in that: The protrusion height of the protrusion structure relative to the bottom plane of the outer rotor iron shell is 0.3-5mm.
5. The brushless motor outer rotor iron shell according to claim 4, characterized in that: The protrusion height of the protrusion structure relative to the bottom plane of the outer rotor iron shell is 1 mm.
6. The brushless motor outer rotor iron shell according to any one of claims 1 to 5, characterized in that: A circular boss is provided at the center of the bottom of the outer rotor iron shell, which is concave on one side and convex on the other side. The top surface of the circular boss is a plane, and the mounting hole is opened at the center of the top surface of the circular boss.
7. The brushless motor outer rotor iron shell according to claim 6, characterized in that: The wall thickness tolerance of the outer rotor iron shell is less than 0.015 mm.
8. The brushless motor outer rotor iron shell according to claim 6, characterized in that: The surface of the outer rotor iron shell is smooth and free of burrs.