Motor rotor assembly, motor and vehicle
By using a design with textured edges and convex ribs on the outer periphery of the rotor shaft body for interference fit, combined with fasteners and balance plates, the problem of insufficient assembly precision of the motor rotor is solved, thereby improving processing efficiency and motor performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIAOMI EV TECH CO LTD
- Filing Date
- 2025-05-19
- Publication Date
- 2026-05-05
AI Technical Summary
The existing motor rotor has insufficient assembly precision, and the rotor shaft is prone to deformation during machining and heat treatment, which affects the overall performance of the motor.
The rotor shaft body has textured outer circumference, with the protrusions and outer circumference surface of the body having an interference fit. Part of the rotor core material is filled in the texture and processed by knurling or thread rolling to avoid milling keyways. Combined with the design of the fixing parts and balance plate, the assembly accuracy and stability are improved.
It reduces the machining time of the rotor shaft, improves the dimensional accuracy of the rotor shaft and the assembly accuracy of the motor rotor assembly, enhances the overall performance and structural stability of the motor, and reduces production costs and vibration.
Smart Images
Figure CN224204843U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of electric motor technology, and more specifically, to an electric motor rotor assembly, an electric motor, and a vehicle. Background Technology
[0002] An electric motor is a device that converts electrical energy into mechanical energy. Its structure consists of a rotor, a stator, and other accessories. The working principle of an electric motor is based on the force exerted by a magnetic field on an electric current, which causes the motor to rotate.
[0003] The assembly precision of existing motor rotors needs to be improved.
[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0005] This disclosure provides an electric motor rotor assembly, an electric motor, and a vehicle, which can improve the assembly accuracy of the electric motor rotor assembly.
[0006] According to a first aspect of this disclosure, an electric motor rotor assembly is provided, comprising:
[0007] The rotor shaft includes a main body portion, the outer periphery of which has multiple textures;
[0008] The rotor core has a mating through hole, the wall of which has multiple protrusions, which are distributed circumferentially along the through hole. The protrusions are interference-fitted with the outer peripheral surface of the main body. Part of the rotor core material is filled in the texture, and the width of the protrusions is at least twice the width of the texture.
[0009] In one embodiment of this disclosure, a portion of the outer peripheral surface of the main body extends between two adjacent protrusions.
[0010] In one embodiment of this disclosure, a plurality of the textures are distributed at circumferential intervals along the main body portion, and the textures extend axially along the main body portion.
[0011] In one embodiment of this disclosure, the rotor shaft further includes a first end head and a second end head, the first end head and the second end head being located at both ends of the main body and respectively connected to the main body;
[0012] The motor rotor assembly also includes a fixing member connected to the first end head and the second end head, and used to clamp the two ends of the rotor core.
[0013] In one embodiment of this disclosure, the radius of the main body portion increases sequentially along the direction away from the first end head.
[0014] In one embodiment of this disclosure, the fastener includes a retaining ring and a pressure ring;
[0015] The fixed ring is coaxially disposed at the second end head, the pressure ring is interference-fitted to the first end head, and the rotor core is clamped between the pressure ring and the fixed ring.
[0016] In one embodiment of this disclosure, the motor rotor assembly further includes two balance plates;
[0017] Both balance plates are sleeved on the main body, one balance plate abuts between the rotor core and the fixed ring, and the other balance plate abuts between the rotor core and the pressure ring.
[0018] In one embodiment of this disclosure, the rotor core has at least one weight-reducing hole that extends through the rotor core along its axial direction.
[0019] In one embodiment of this disclosure, the rotor core has at least one mounting hole for mounting a magnet, the mounting hole extending through the rotor core along its axial direction.
[0020] In one embodiment of this disclosure, the rotor core includes a plurality of cores stacked along the axial direction of the main body.
[0021] According to a second aspect of this disclosure, an electric motor is provided, comprising the motor rotor assembly described in any of the above embodiments.
[0022] According to a third aspect of this disclosure, a vehicle is provided, including the motor described in the above embodiments.
[0023] The rotor shaft has textured surfaces on its main body, with protrusions that are interference-fitted with the outer circumference of the main body. Part of the rotor core material is filled within the textured surfaces, allowing for assembly of the rotor shaft and rotor core without the need to mill keyways on the main body. The textured surfaces can be machined using knurling or thread rolling processes, reducing the machining time of the rotor shaft and improving its machining efficiency. When the rotor shaft is heat-treated, compared to a rotor shaft with keyways, the textured rotor shaft exhibits less deformation, thereby improving the dimensional accuracy of the rotor shaft. This is beneficial for improving the assembly accuracy of the motor rotor assembly and the overall performance of the motor.
[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description
[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.
[0026] Figure 1 This is a schematic diagram of the structure of a motor rotor assembly in one embodiment of this disclosure.
[0027] Figure 2 This is an exploded view of the motor rotor assembly in one embodiment of this disclosure.
[0028] Figure 3 This is a schematic diagram of the assembly of the rotor shaft and rotor core in one embodiment of this disclosure.
[0029] Figure 4 This is a schematic diagram of the rotor shaft structure in one embodiment of the present disclosure.
[0030] Figure 5 This is a schematic diagram of the rotor core structure in one embodiment of this disclosure.
[0031] Explanation of reference numerals in the attached figures:
[0032] 1. Rotor shaft; 11. Main body; 12. First end head; 121. First end section; 122. First connecting section; 123. Second connecting section; 13. Second end head; 131. Second end section; 132. Third connecting section; 2. Rotor core; 21. Protruding rib; 22. Weight reduction hole; 23. Mounting hole; 3. Fixing component; 31. Fixing ring; 32. Pressure ring; 4. Balance plate. Detailed Implementation
[0033] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.
[0034] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.
[0035] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.
[0036] In related technologies, the rotor shaft and the iron core of a motor are fixedly connected by a key. However, milling keyways on the shaft increases the machining time, and the presence of keyways during heat treatment can easily cause deformation of the shaft (e.g., circumferential deformation), reducing the assembly accuracy of the motor rotor.
[0037] To address the aforementioned problems, this disclosure provides a motor rotor assembly. See also... Figures 1-5 The motor rotor assembly includes a rotor shaft 1 and a rotor core 2. The rotor shaft 1 includes a main body 11, the outer periphery of which has multiple textures. The rotor core 2 has a mating through hole, the hole wall of which has multiple protrusions 21. These protrusions 21 are spaced apart circumferentially along the through hole, and are interference-fitted with the outer periphery of the main body 11. Part of the material of the rotor core 2 fills the textures, and the width of each protrusion 21 is at least twice the width of the texture.
[0038] It should be noted that, in the embodiments of this disclosure, the ridge 21 has two opposing sidewalls, and the width of the ridge 21 refers to the distance between the two opposing sidewalls of the ridge 21. The texture is a groove structure, and the texture has two opposing sidewalls, and the width of the texture is the distance between the two opposing sidewalls of the fingerprint texture.
[0039] Thus, in the embodiments of this disclosure, the main body 11 of the rotor shaft 1 is provided with texture, and the protrusion 21 is interference-fitted with the outer peripheral surface of the main body 11. Part of the material of the rotor core 2 is filled in the texture. The assembly of the rotor shaft 1 and the rotor core 2 can be achieved without milling a keyway in the main body 11. The texture can be processed by knurling or thread rolling, which reduces the processing time of the rotor shaft 1 and improves the processing efficiency of the rotor shaft 1. When the rotor shaft 1 is heat-treated, compared with the rotor shaft 1 with a keyway, the rotor shaft 1 with texture has less deformation, thereby improving the dimensional accuracy of the rotor shaft 1. This is beneficial to improving the assembly accuracy of the motor rotor assembly and the overall performance of the motor.
[0040] In one embodiment of this disclosure, the interference fit between the protrusion 21 and the outer peripheral surface of the main body 11 is 0.14 mm to 0.16 mm. For example, the interference fit between the protrusion 21 and the outer peripheral surface of the main body 11 can be 0.14 mm, 0.15 mm, or 0.16 mm.
[0041] In one embodiment of this disclosure, the width of the ridge 21 is two, three, four, or five times greater than the width of the texture, so as to achieve an interference fit between the ridge 21 and the outer peripheral surface of the main body 11, thereby improving the structural stability of the motor rotor assembly.
[0042] In one embodiment of this disclosure, see Figure 1 , Figure 3 A portion of the outer circumferential surface of the main body 11 extends between two adjacent protrusions 21. In this way, during the installation of the rotor shaft 1 and the rotor core 2, a portion of the outer circumferential surface of the main body 11 extends between two adjacent protrusions 21 to avoid obstructing a portion of the main body 11, preventing the rotor shaft 1 and rotor core 2 from jamming during installation, and facilitating the smooth installation of the rotor shaft 1 and rotor core 2.
[0043] In one embodiment of this disclosure, the rotor shaft 1 and the rotor core 2 can be installed by press-fitting to achieve an interference fit between the rotor shaft 1 and the rotor core 2, thereby improving the structural stability of the motor rotor assembly.
[0044] In one embodiment of this disclosure, see Figure 2 , Figure 4Multiple textures are spaced apart circumferentially along the main body 11, extending axially and penetrating the main body 11. Thus, during the installation of the rotor shaft 1 and rotor core 2, since the extension direction of the textures is the same as the installation direction (axial direction of the rotor core 2), the resistance experienced by the rotor core 2 during installation can be reduced, thereby facilitating the smooth installation of the rotor shaft 1 and rotor core 2. In other embodiments of this disclosure, the extension direction of the textures can form an angle greater than 0° with the axial direction of the rotor shaft 1; for example, the angle between the extension direction of the textures and the axial direction of the rotor shaft 1 can be 1°, 2°, 3°, 4°, etc.
[0045] In one embodiment of this disclosure, see Figure 1 , Figure 2 The rotor shaft 1 also includes a first end head 12 and a second end head 13, which are located at both ends of the main body 11 and are integrally connected to the main body 11. The motor rotor assembly also includes a fixing member 3, which is connected to the first end head 12 and the second end head 13 and is used to clamp both ends of the rotor core 2. In this way, the fixing member 3 can clamp both ends of the rotor core 2, preventing the rotor core 2 from moving axially along the rotor shaft 1, thereby improving the structural stability of the motor rotor assembly.
[0046] In one embodiment of this disclosure, see Figure 1 , Figure 2 The fixing component 3 includes a fixing ring 31 and a pressure ring 32. The fixing ring 31 is coaxially sleeved on the second end head 13 and is integrally connected to the second end head. The pressure ring 32 is interference-fitted to the first end head 12. The pressure ring 32 can be press-fitted to the first end head 12. The rotor core 2 is clamped between the pressure ring 32 and the fixing ring 31. In this way, the fixing ring 31 and the pressure ring 32 can clamp both ends of the rotor core 2 to prevent the rotor core 2 from moving axially along the rotor shaft 1, thereby improving the structural stability of the motor rotor assembly.
[0047] In one embodiment of this disclosure, the pressure ring 32 can be sleeved on the first end head 12 and threadedly connected to the first end head 12, so as to realize the detachable setting of the pressure ring 32 and facilitate the replacement or maintenance of the motor rotor assembly.
[0048] In one embodiment of this disclosure, the radius of the main body 11 increases sequentially along the direction away from the first end head 12. That is, the main body 11 has a taper, and the radius of the end of the main body 11 near the first end head 12 is smaller than the radius of the end of the main body 11 near the second end head 13. This facilitates the pressing of the rotor core 2 and the pressure ring 32 from the end of the first end head 12 into the main body 11, reducing the installation difficulty of the motor rotor assembly.
[0049] In one embodiment of this disclosure, the taper of the main body 11 can be 0.12 to 0.18. For example, the taper of the main body 11 can be 0.12, 0.13, 0.14, 0.15, 0.16, 0.17 or 0.18, so that the main body 11 has a suitable taper, which not only prevents the structural strength of the rotor shaft 1 from being affected by excessive taper, but also avoids the smooth installation of the rotor shaft 1 and the rotor core 2 from being affected by insufficient taper.
[0050] In one embodiment of this disclosure, see Figure 1 , Figure 2 The motor rotor assembly also includes two balancing plates 4. Both balancing plates 4 are fitted onto the main body 11. One balancing plate 4 abuts against the rotor core 2 and the retaining ring 31, while the other balancing plate 4 abuts against the rotor core 2 and the pressure ring 32. The balancing plates 4 and the main body 11 are press-fitted together to achieve an interference fit. Thus, by setting two balancing plates 4 at both ends of the rotor core 2, the center of the motor rotor assembly is balanced, reducing vibration during rotation and improving the motor's performance.
[0051] In one embodiment of this disclosure, see Figure 2 , Figure 4 The first end head 12 includes a first end head segment 121, a first connecting segment 122, and a second connecting segment 123 integrally connected in sequence. The end of the second connecting segment 123 furthest from the first connecting segment 122 is integrally connected to the main body 11. The radius of the first end head segment 121 is smaller than the radius of the first connecting segment 122, the radius of the first connecting segment 122 is smaller than the radius of the second connecting segment 123, and the radius of the second connecting segment 123 is smaller than the radius of the main body 11. The pressure ring 32 can be fitted and interference-fitted onto the second connecting segment 123. Thus, the first end head segment 121 and the first connecting segment 122 enable a rotatable connection between the rotor shaft 1 and the motor bearings, while the second connecting segment 123 facilitates an interference fit between the pressure ring 32 and the first end head 12.
[0052] In one embodiment of this disclosure, see Figure 2 , Figure 4 The second end head 13 includes an integrally connected second end head section 131 and a third connecting section 132. The end of the third connecting section 132 furthest from the second end head section 131 is integrally connected to the fixing ring 31. The radius of the second end head section 131 is smaller than the radius of the third connecting section 132, the radius of the third connecting section 132 is smaller than the radius of the fixing ring 31, and the radius of the fixing ring 31 is larger than the radius of the main body 11. In this way, the rotational connection between the rotor shaft 1 and the motor bearing can be achieved through the second end head section 131 and the second connecting section 132.
[0053] In one embodiment of this disclosure, the rotor shaft 1, rotor core 2, balance plate 4, and pressure ring 32 can be assembled by integral pressing, avoiding the cumbersome process of step-by-step pressing. This eliminates the need for excessive assembly stations and equipment to achieve step-by-step pressing, reduces the assembly time of the motor rotor assembly, improves assembly efficiency, and lowers production costs.
[0054] In one embodiment of this disclosure, see Figure 5 There are eight protrusions 21, which are evenly distributed along the circumference of the mating through hole.
[0055] In one embodiment of this disclosure, see Figure 3 , Figure 5 The rotor core 2 has at least one weight-reducing hole 22, which penetrates the rotor core 2 along its axial direction. The weight-reducing hole 22 can be a square hole, a circular hole, an irregularly shaped hole, etc., and is not limited in this embodiment. The number of weight-reducing holes 22 can be one, two, three, four, five, six, etc. Multiple weight-reducing holes 22 can be evenly distributed along the circumference of the rotor core 2 to reduce the weight of the rotor core 2 and reduce the load during motor operation.
[0056] In one embodiment of this disclosure, see Figure 3 , Figure 5 The rotor core 2 has at least one mounting hole 23 for mounting a magnet, and the mounting hole 23 penetrates the rotor core 2 along its axial direction. The mounting hole 23 can be a square hole, a circular hole, an irregularly shaped hole, etc., and is not limited in this embodiment. The number of mounting holes 23 can be one, two, three, four, five, six, etc. Multiple mounting holes 23 can be evenly distributed along the circumference of the rotor core 2, and the mounting holes 23, weight-reducing holes 22, and mating through holes are distributed sequentially along the radial direction of the rotor core 2. Thus, the mounting holes 23 facilitate the mounting of magnets, enabling the magnets to generate a strong magnetic field, thereby improving the efficiency and overall performance of the motor.
[0057] In one embodiment of this disclosure, the rotor core 2 may include multiple cores, the cores being made of silicon steel sheets, and the multiple cores are stacked along the axial direction of the main body 11. Thus, by stacking multiple cores to form the rotor core 2, eddy current losses and hysteresis losses are reduced, the heat generated by the rotor core 2 is decreased, and the service life of the motor is improved.
[0058] This disclosure also provides an electric motor for use in an electric drive system of a vehicle. The motor may include a housing, a stator, and a motor rotor assembly as described in any of the above embodiments. Both the stator and the motor rotor assembly are housed within the housing. The stator is mounted in the housing and has coils wound around it. The rotor shaft 1 of the motor rotor assembly is rotatably mounted to the housing via bearings, so that the motor rotor assembly can rotate relative to the stator under the influence of current to output rotational force. This motor possesses all the beneficial effects of the motor rotor assembly described in the above embodiments, which will not be elaborated upon here.
[0059] This disclosure also provides a vehicle, including a body and an electric drive system. The vehicle can be a new energy vehicle, a hybrid vehicle, a traditional fuel vehicle, or other types of vehicles. The vehicle can be an electric bicycle, motorcycle, automobile, truck, or engineering vehicle. The electric drive system is located in the body and includes a battery, a motor controller, and the motor described in the above embodiments. The battery is electrically connected to the motor controller, and the motor controller is electrically connected to the motor. The motor controller provides alternating current to the motor. This vehicle possesses all the beneficial effects of the motor described in the above embodiments, which will not be elaborated upon here.
[0060] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.
Claims
1. A motor rotor assembly, characterized in that, include: The rotor shaft (1) includes a main body (11), the outer periphery of which has multiple textures; The rotor core (2) has a mating through hole, the hole wall of which has a plurality of protrusions (21), the plurality of protrusions (21) being distributed circumferentially at intervals along the mating through hole, the protrusions (21) being interference fit with the outer peripheral surface of the main body (11), a portion of the material of the rotor core (2) being filled in the texture, and the width of the protrusions (21) being at least twice the width of the texture.
2. The motor rotor assembly according to claim 1, characterized in that, A portion of the outer periphery of the main body (11) extends between two adjacent protrusions (21).
3. The motor rotor assembly according to claim 1, characterized in that, The plurality of the textures are distributed circumferentially along the main body (11) and the textures extend axially along the main body (11).
4. The motor rotor assembly according to claim 1, characterized in that, The rotor shaft (1) further includes a first end head (12) and a second end head (13), the first end head (12) and the second end head (13) being located at both ends of the main body (11) and respectively connected to the main body (11); The motor rotor assembly also includes a fixing member (3), which is connected to the first end head (12) and the second end head (13) and is used to clamp the two ends of the rotor core (2).
5. The motor rotor assembly according to claim 4, characterized in that, The radius of the main body (11) increases sequentially along the direction away from the first end head (12).
6. The motor rotor assembly according to claim 5, characterized in that, The fastener (3) includes a retaining ring (31) and a pressure ring (32); The fixing ring (31) is coaxially disposed on the second end head (13), the pressure ring (32) is interference-fitted to the first end head (12), and the rotor core (2) is clamped between the pressure ring (32) and the fixing ring (31).
7. The motor rotor assembly according to claim 6, characterized in that, The motor rotor assembly also includes two balance plates (4); Both balance plates (4) are sleeved on the main body (11). One balance plate (4) abuts between the rotor core (2) and the fixing ring (31), and the other balance plate (4) abuts between the rotor core (2) and the pressure ring (32).
8. The motor rotor assembly according to claim 1, characterized in that, The rotor core (2) has at least one weight-reducing hole (22) that penetrates the rotor core (2) along the axial direction of the rotor core (2).
9. The motor rotor assembly according to claim 1, characterized in that, The rotor core (2) has at least one mounting hole (23) for mounting a magnet, the mounting hole (23) extending through the rotor core (2) along the axial direction of the rotor core (2).
10. The motor rotor assembly according to any one of claims 1 to 9, characterized in that, The rotor core (2) includes multiple cores, which are stacked along the axial direction of the main body (11).
11. An electric motor, characterized in that, Includes the motor rotor assembly as described in any one of claims 1 to 10.
12. A vehicle, characterized in that, Includes the motor as described in claim 11.