Rotor and electric machine
Patent Information
- Application Number
- CN202522074991.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-26
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-09-26
AI Technical Summary
但是上述这样一种硬配软的过盈配合容易出现切料现象，尤其是为了增加圆周约束而在转子轴上设置滚花结构时
[0016]本申请的转子及电机，转子轴包括与平衡件配合的第一配合部，所述第一配合部包括与所述平衡件间隙配合的悬空段以及与所述平衡件过盈配合的过盈段，所述悬空段和所述过盈段相连，所述过盈段的外侧壁面凸设有滚花结构，通过在具有滚花的转子轴上分别配置过盈段和悬空段，从而使切屑容纳于悬空段处，防止切屑散布，还可以利用切屑填充悬空段处的间隙以在该段加强转子轴与平衡件的配合强度，最终提高转子和电机的质量。
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Figure CN224790416U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of motor technology, and in particular to a rotor and a motor. Background Technology
[0002] With the development of motor technology, the types of motors are constantly increasing, and correspondingly, the quality requirements for motors in various power tools are also getting higher and higher.
[0003] Currently, most permanent magnet motor rotors in lithium-ion battery tools employ an interference fit assembly structure, with an iron core, balance ring, fan, magnet, and other components mounted on the rotor shaft. To meet quality requirements, the rotor shaft is generally made of a high-hardness metal, while the hardness of the mating balance ring and fan is relatively lower. However, this hard-to-soft interference fit is prone to shearing, especially when a knurled structure is added to the rotor shaft to increase circumferential constraint.
[0004] In the cutting process, chips generated by components such as the balance ring may be magnetic and adhere to the permanent magnet, making them difficult to remove. If these chips are mixed into the final assembly, during the trial aging process, the high-speed rotation of the motor will cause the chips to be thrown outwards by centrifugal force, potentially leading to short circuits. This could result in damage to the enameled wires, jamming of the machine's mechanical structure, and other problems, posing a significant quality risk. Utility Model Content
[0005] The purpose of this application is to provide a rotor and motor that can help reduce chip dispersion and improve the quality of the motor.
[0006] To address the aforementioned technical problems, embodiments of this application provide a rotor. The rotor includes a rotor shaft, an iron core, and a balancing component. The iron core and the balancing component are fixed to the rotor shaft. The rotor shaft includes a first mating portion that mates with the balancing component. The first mating portion includes a suspended section that has a clearance fit with the balancing component and an interference section that has an interference fit with the balancing component. The suspended section and the interference section are connected, and the outer wall surface of the interference section is provided with a knurled structure.
[0007] An embodiment of this application also provides an electric motor, which includes the rotor described above.
[0008] In some embodiments, the core and the balancer are axially distributed along the rotor shaft, and the interference section is closer to the core than the suspended section.
[0009] In some embodiments, the rotor includes a pair of balancing members located on opposite sides of the iron core in the axial direction, the balancing members being in close contact with the iron core.
[0010] In some embodiments, the rotor shaft includes a second mating portion that is interference-fitted with the iron core, and the outer wall surface of the second mating portion is provided with the knurled structure.
[0011] In some embodiments, the axial length of the interference section is greater than that of the suspended section, and the axial length of the suspended section is not less than 1 / 2 of that of the interference section.
[0012] In some embodiments, the balancing member has an inner hole in the middle, the rotor shaft passes through the inner hole and cooperates with the balancing member, and the diameter of the inner hole is smaller than the maximum diameter of the interference section and larger than the minimum diameter of the interference section.
[0013] In some embodiments, the diameter of the suspended section is larger than the minimum diameter of the interference section.
[0014] In some embodiments, the height of the knurled structure is at least five times the width of the gap between the suspended section and the balancing member.
[0015] In some embodiments, a fan fixed to the rotor shaft is also included, the rotor shaft including a third mating portion that mates with the fan, the third mating portion including a clearance fit portion and an interference fit portion connected to each other with the fan.
[0016] The rotor and motor of this application include a rotor shaft comprising a first mating portion that mates with a balancing component. The first mating portion includes a suspended section that has a clearance fit with the balancing component and an interference fit section that has an interference fit with the balancing component. The suspended section and the interference fit section are connected. The outer wall surface of the interference fit section is provided with a knurled structure. By configuring the interference fit section and the suspended section on the knurled rotor shaft respectively, the chips are contained in the suspended section, preventing chip scattering. The chips can also be used to fill the gap in the suspended section to strengthen the fit between the rotor shaft and the balancing component in that section, ultimately improving the quality of the rotor and motor. Attached Figure Description
[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.
[0018] Figure 1 These are exploded views of rotors provided in some embodiments of this application;
[0019] Figure 2 This is a half-sectional view of a rotor provided in some embodiments of this application;
[0020] Figure 3 This is a cross-sectional view of the rotor shaft provided in some embodiments of this application;
[0021] Figure 4 yes Figure 2 A magnified view of part A in the middle. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0024] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.
[0025] Figure 1 These are exploded views of rotors provided in some embodiments of this application; Figure 2 This is a half-sectional view of a rotor provided in some embodiments of this application; Figure 3 This is a cross-sectional view of the rotor shaft provided in some embodiments of this application; Figure 4 yes Figure 2 A magnified view of part A in the middle.
[0026] This utility model proposes a rotor.
[0027] like Figures 1 to 4As shown, in one embodiment of this utility model, the rotor includes a rotor shaft 100, an iron core 200, and a balancing component 300. The rotor shaft 100 extends axially, and the iron core 200 and the balancing component 300 are sleeved on the outside of the rotor shaft 100. The rotor shaft 100 is fixed to the iron core 200 and the balancing component 300, respectively. The rotor shaft 100 is the power output part of the motor and can be connected to the actuator of the power tool to transmit the driving force and motion generated by the motor to the actuator end, thereby realizing the corresponding processing operation. The rotor in this embodiment is the rotor of an internal rotor type motor. The rotor shaft 100 is fixedly connected to the iron core 200 and can rotate synchronously with the iron core 200. The motor shaft has a certain length and can be connected to the input end of the transmission mechanism in the power tool.
[0028] The rotor shaft 100 can be divided into multiple parts along the axial direction. The rotor shaft 100 includes a first mating portion 110 that mates with the balancing member 300. The rotor shaft 100 mates with the balancing member 300 through this first mating portion 110. After mating, the rotor shaft 100 and the balancing member 300 are relatively fixed. Specifically, the first mating portion 110 includes a suspended section 111 and an interference section 112. In the suspended section 111, the first mating portion 110 has a clearance fit with the balancing member 300, while in the interference section 112, the first mating portion 110 has an interference fit with the balancing member 300. The suspended section 111 and the interference section 112 are connected, allowing chips generated by the interference fit between the rotor shaft 100 and the balancing member 300 to enter the suspended section 111. The outer wall of the interference fit section 112 is provided with a knurled structure 140. The chips are mainly generated when the knurled structure 140 cuts into the balancing component 300 during the assembly of the rotor shaft 100 and the balancing component. The chips then enter the suspended section 111 and are contained in the gap between the rotor shaft 100 and the balancing component 300 at that location. Containing the chips can prevent them from spreading further, and the chips can also fill the gap at the suspended section 111 to strengthen the fit between the rotor shaft 100 and the balancing component 300 in that section, ultimately improving the quality of the rotor and the motor.
[0029] In some embodiments, the core 200 and the balancer 300 are distributed axially along the rotor shaft 100, with the interference fit section 112 closer to the core 200 relative to the suspended section 111. The fit between the core 200 and the rotor shaft 100 can also generate chips, which, together with the chips from the interference fit section 112, can eventually converge at the suspended section 111. Furthermore, the suspended section 111 is positioned away from the core 200 relative to the interference fit section 112, meaning that the clearance fit area between the balancer 300 and the rotor shaft 100 has an opening on at least one side to allow air to escape, enabling chips to smoothly enter the clearance. Further, the rotor includes a pair of balancers 300 located on opposite sides of the core 200 in the axial direction, with each balancer 300 positioned close to the core 200. The balancer 300 can be a disc-shaped structure (thicker in the middle and thinner at the edges), an annular shape, or a block shape, etc. When a pair of balancing members 300 are provided, the interference section 112 corresponding to each balancing member 300 is closer to the iron core 200 than its suspended section 111. That is, the clearance fit area between each balancing member 300 and the rotor shaft 100 has an opening on at least one side, which can exhaust air so that the chips can smoothly enter the gap.
[0030] In some embodiments, among the multiple axially divided portions of the rotor shaft 100, the rotor shaft 100 includes a second mating portion 120 that is interference-fitted with the iron core 200, through which the rotor shaft 100 engages with the iron core 200. The outer wall surface of the second mating portion 120 is provided with the aforementioned knurled structure 140. Preferably, the knurled structure 140 extends continuously from the first mating portion 110 to the second mating portion 120 on the rotor shaft 100.
[0031] The knurled structure 140 is a raised pattern provided on the outer wall surface of the rotor shaft 100 to increase friction and make the assembly between the rotor shaft 100 and the iron core 200 and the balancer 300 more secure. In some embodiments, the diameter of the rotor shaft 100 is small, and an interference fit cannot be achieved between it and the iron core 200 or the balancer 300 before the knurled structure 140 is added; after adding the knurled structure 140, the overall diameter of the rotor shaft 100 becomes relatively larger, and the first mating part 110 of the rotor shaft 100 can achieve an interference fit with the balancer 300, and the second mating part 120 of the rotor shaft 100 can achieve an interference fit with the iron core 200. In other embodiments, the diameter of the rotor shaft 100 is large, and an interference fit can already be achieved between it and the iron core 200 or the balancer 300 before the knurled structure 140 is added; adding the knurled structure 140 can enhance the fit between the rotor shaft 100 and the iron core 200 or the balancer 300.
[0032] To ensure a more secure fit between the rotor shaft 100 and the balancing component 300, the axial length of the interference section 112 is greater than that of the suspended section 111. This ensures sufficient interference fit of the first mating part 110 of the rotor shaft 100, reducing the possibility of loosening between the rotor shaft 100 and the balancing component 300. Testing shows that the axial length of the suspended section 111 is not less than half that of the interference section 112, providing sufficient space to accommodate chips. Specifically, the first mating part 110 includes the suspended section 111 and the interference section 112. In the suspended section 111, the first mating part 110 has a clearance fit with the balancing component 300, and the rotor shaft 100 at the suspended section 111 does not have a knurled structure 140. In the interference section 112, the first mating part 110 has an interference fit with the balancing component 300, and the rotor shaft 100 at the interference section 112 has a knurled structure 140.
[0033] In some embodiments, the balancing member 300 has an inner hole in its center. When the balancing member 300 is annular, the inner hole is a through hole penetrating the center of the balancing member 300. The rotor shaft 100 passes through the inner hole and mates with the balancing member 300. The portion of the rotor shaft 100 that mates with the inner hole wall is the first mating portion 110. The diameter of the inner hole is smaller than the maximum diameter of the interference section 112 of the first mating portion 110, and the diameter of the inner hole is larger than the minimum diameter of the interference section 112 of the first mating portion 110. For example, if the maximum diameter of the interference section 112 is 12.06 mm and the minimum diameter is 11 mm, the corresponding inner hole diameter can be 11.92 mm.
[0034] The maximum diameter of the aforementioned interference section 112 is the diameter of the rotor shaft 100 including the knurled first mating part 110, and the minimum diameter of the interference section 112 is the diameter of the rotor shaft 100 excluding the knurled first mating part 110. Specifically, the rotor shaft 100 with the knurled structure 140 has a roughly circular cross-section perpendicular to its axis. The outer periphery of this cross-section is wavy, with the crest being the top of the knurled structure 140 and the trough being the outer wall of the rotor shaft 100. The length of the line segment passing through the center of the cross-section of the rotor shaft 100 and having both ends located at the top of the knurled structure 140 is the maximum diameter of the aforementioned interference section 112, and the length of the line segment passing through the center of the cross-section of the rotor shaft 100 and having both ends located on the outer wall is the minimum diameter of the aforementioned interference section 112.
[0035] The inner diameter is smaller than the maximum diameter of the interference section 112 and larger than the minimum diameter of the interference section 112, so that the knurled structure 140 directly contacts and interferes with the balancing part 300. The outer wall surface of the bottom of the knurled structure 140 does not directly contact the balancing part 300, and the chips can also be accommodated in the gap between the knurled structures 140.
[0036] In some embodiments, the diameter of the suspended section 111 is larger than the minimum diameter of the interference section 112. For example, the diameter of the suspended section 111 is 11.89 mm, and the corresponding minimum diameter of the interference section 112 is 11 mm. The diameter of the suspended section 111 is the diameter of the first mating portion 110 without the knurled structure 140. Since the diameter of the suspended section 111 is larger than the minimum diameter of the interference section 112, the gap between the suspended section 111 and the balancing member 300 is smaller than the gap between the outer wall surface of the interference section 112 and the balancing member 300. The chips are preferentially accommodated in at least a portion of the gap between the knurled structures 140 of the interference section 112.
[0037] In some embodiments, the height of the knurled structure 140 is at least five times the width of the gap between the suspended section 111 and the balancing member 300. The height of the knurled structure 140 is the height difference between the knurled structure 140 protruding from the outer wall of the interference section 112. Setting the height of the knurled structure 140 to be much greater than the width of the gap between the suspended section 111 and the balancing member 300 ensures that the knurled structure 140 has sufficient height to provide a firm interference fit, while also allowing chips to appropriately fill the gap in the suspended section 111. The chips filling the gap in the suspended section 111 not only prevent chips from further mixing into other parts of the motor and causing quality degradation, but also make the fit between the suspended section 111 and the balancing member 300 more stable and firm.
[0038] In some embodiments, the rotor also includes a fan 400 fixed to the rotor shaft 100. The rotor shaft 100 includes a third mating portion 130 that mates with the fan 400. The third mating portion 130 includes a clearance fit portion and an interference fit portion connected to each other with the balance member 300. That is, the third mating portion 130 is similar to the first mating portion 110, both having continuous clearance fit portions and interference fit portions, and their functions are also similar, which will not be described in detail here.
[0039] Some embodiments of this application also provide an electric motor, which includes the rotor described above.
[0040] The rotor and motor of this application include a rotor shaft 100 comprising a first mating portion 110 that mates with a balancing member 300. The first mating portion 110 includes a suspended section 111 that has a clearance fit with the balancing member 300 and an interference section 112 that has an interference fit with the balancing member 300. The suspended section 111 and the interference section 112 are connected. The outer wall surface of the interference section 112 is provided with a knurled structure 140. By configuring the interference section 112 and the suspended section 111 on the knurled rotor shaft 100 respectively, the chips are contained in the suspended section 111, preventing the chips from scattering. The chips can also be used to fill the gap in the suspended section 111 to strengthen the fit between the rotor shaft 100 and the balancing member 300 in this section, ultimately improving the quality of the rotor and motor.
[0041] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application.
Claims
1. A rotor comprising a rotor shaft, an iron core, and a balancing component, wherein the iron core and the balancing component are fixed to the rotor shaft, characterized in that: The rotor shaft includes a first mating part that mates with the balancing component. The first mating part includes a suspended section that is clearance-fitted with the balancing component and an interference section that is interference-fitted with the balancing component. The suspended section and the interference section are connected. The outer wall surface of the interference section is provided with a knurled structure.
2. The rotor according to claim 1, characterized in that: The iron core and the balancer are distributed along the axial direction of the rotor shaft, and the interference section is closer to the iron core than the suspended section.
3. The rotor according to claim 2, characterized in that: The rotor includes a pair of balancing members located on both sides of the iron core in the axial direction, the balancing members being in close contact with the iron core.
4. The rotor according to claim 1, characterized in that: The rotor shaft includes a second mating part that is interference-fitted with the iron core, and the outer wall surface of the second mating part is provided with the knurled structure.
5. The rotor according to claim 1, characterized in that: The axial length of the interference section is greater than that of the suspended section, and the axial length of the suspended section is not less than 1 / 2 of that of the interference section.
6. The rotor according to claim 1, characterized in that: The balancing component has an inner hole in the middle, and the rotor shaft passes through the inner hole and cooperates with the balancing component. The diameter of the inner hole is smaller than the maximum diameter of the interference section and larger than the minimum diameter of the interference section.
7. The rotor according to claim 6, characterized in that: The diameter of the suspended section is greater than the minimum diameter of the interference section.
8. The rotor according to claim 6, characterized in that: The height of the knurled structure is at least five times the width of the gap between the suspended section and the balancing component.
9. The rotor according to claim 1, characterized in that: It also includes a fan fixed to the rotor shaft, the rotor shaft including a third mating part that mates with the fan, the third mating part including a clearance fit portion and an interference fit portion connected to each other with the fan.
10. An electric motor, characterized in that: Includes the rotor as described in any one of claims 1 to 9.