Rotor assembly, motor assembly and electronic device

Abstract

A rotor assembly (200), a motor assembly (10), and an electronic device. The rotor assembly comprises a rotor yoke (210), a plurality of magnets (220), and retaining rings (230), wherein a first side surface of the rotor yoke is provided with a plurality of first mounting slots (213) arranged at intervals in the circumferential direction of the rotor yoke; the first side surface is configured to face a stator assembly (100); the plurality of magnets are respectively mounted in the plurality of first mounting slots; and the retaining rings are arranged on the first side surface, and are located at an end of each magnet in the axial direction of the rotor yoke, so as to limit the axial movement of the magnets relative to the rotor yoke.

Description

Rotor assembly, motor assembly and electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 2025104841771, filed on April 16, 2025, entitled “Rotor Assembly, Motor Assembly and Electronic Equipment”, which is incorporated herein by reference in its entirety.

[0002] [Technical Field]

[0003] This application relates to the field of motor technology, and in particular to a rotor assembly, motor assembly and electronic equipment.

[0004] [Background Technology]

[0005] In existing rotor assembly methods, the magnets are installed onto the isolator after the rotor yoke is secured to the isolator with screws. This process makes rotor assembly difficult. Furthermore, when the rotor assembly rotates at high speed, the magnets are highly likely to detach from the rotor yoke, resulting in low reliability of the rotor assembly.

[0006] [Summary of the Invention]

[0007] This application provides a rotor assembly, a motor assembly, and an electronic device to solve the technical problems of high assembly difficulty and low reliability of existing rotor assemblies.

[0008] To solve the above-mentioned technical problems, this application provides a rotor assembly, which includes a rotor yoke, a plurality of magnets and a limiting ring. A first side of the rotor yoke is provided with a plurality of first mounting grooves spaced apart along the circumference of the rotor yoke. The first side is configured to face the stator assembly. The plurality of magnets are respectively installed in the plurality of first mounting grooves. The limiting ring is provided on the first side and is located at the end of the magnet in the axial direction of the rotor yoke to limit the axial movement of the magnet relative to the rotor yoke.

[0009] In one embodiment, the limiting ring includes at least one set of rings, which are sleeved on the first side and located at the end of the magnet in the axial direction of the rotor yoke; the set of rings abuts against the end of the magnet in the axial direction.

[0010] In one embodiment, along the axial direction of the rotor yoke, a first protrusion and at least one second protrusion are formed on a first side surface at intervals; a first mounting groove is provided on the first protrusion, and the second protrusion serves as a limiting ring located at the end of the magnet in the axial direction of the rotor yoke.

[0011] In one embodiment, the rotor assembly includes two limiting rings, respectively disposed at the ends of the magnet in the axial direction.

[0012] In one embodiment, the rotor assembly further includes a collar disposed on the second protrusion.

[0013] In one embodiment, the limiting ring protrudes from the magnet in a direction away from the first side along the radial direction of the rotor yoke.

[0014] In one embodiment, the second protrusion is smaller than the first protrusion in the radial direction of the rotor yoke.

[0015] In one embodiment, the magnet is attached to the bottom wall of the first mounting groove.

[0016] To solve the above-mentioned technical problems, this application provides a motor assembly, which includes the rotor assembly and the stator assembly, wherein the stator assembly and the rotor assembly are magnetically coupled.

[0017] In one embodiment, the motor assembly further includes a bearing, one of the stator assembly and the rotor assembly being connected axially to the inner ring of the bearing, and the other of the stator assembly and the rotor assembly being connected axially to the outer ring of the bearing.

[0018] In one embodiment, the stator assembly is sleeved outside the rotor assembly; the stator assembly is connected to the outer ring, and the rotor assembly is connected to the inner ring.

[0019] In one embodiment, the outer ring protrudes from the inner ring toward the stator assembly, and a second mounting groove is provided on the end face of the outer ring toward the stator assembly. The stator assembly is at least partially disposed in the second mounting groove and spaced apart from the inner ring. A third mounting groove is provided on the side of the inner ring toward the rotor assembly, and the rotor assembly is fitted with the stop of the third mounting groove.

[0020] To address the aforementioned technical problems, this application provides an electronic device that includes the aforementioned motor assembly.

[0021] The beneficial effects of this application are as follows: The rotor assembly of this application includes a rotor yoke, multiple magnets, and a limiting ring. The rotor yoke has multiple first mounting slots spaced circumferentially along its first side facing the stator assembly for mounting the magnets. This means the rotor yoke of this application can isolate multiple magnets without the need for additional isolators, reducing the steps required for fixing additional isolators to the rotor yoke during rotor assembly and lowering the assembly difficulty. Furthermore, the rotor yoke can achieve positioning and indexing of multiple magnets without the need for additional isolators, reducing the cost of the rotor assembly. Additionally, the rotor assembly also has a limiting ring on its first side, located at the end of the magnet along the axial direction of the rotor yoke, to limit the magnet along the axial direction of the rotor yoke, preventing the magnet from flying off the rotor yoke and enhancing the reliability of the rotor assembly.

[0022] [Attached Image Description]

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0024] Figure 1 is a schematic diagram of a rotor assembly according to an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of the rotor assembly with magnets in the embodiment of Figure 1;

[0026] Figure 3 is a schematic diagram of another embodiment of the rotor assembly provided in this application;

[0027] Figure 4 is a structural schematic diagram of an embodiment of the motor assembly provided in this application;

[0028] Figure 5 is a structural schematic diagram of an embodiment of the collar provided in this application;

[0029] Figure 6 is a structural schematic diagram of an embodiment of the motor assembly provided in this application;

[0030] Figure 7 is a cross-sectional schematic diagram of one embodiment of the motor assembly of the embodiment in Figure 6.

[0031] Reference numerals: 10-motor assembly; 100-stator assembly; 200-rotor assembly; 210-rotor yoke; 211-first protrusion; 212-second protrusion; 213-first mounting groove; 220-magnet; 230-limiting ring; 231-collar ring; 300-bearing; 310-outer ring; 320-inner ring.

[0032]

Detailed Implementation Methods

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0034] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0035] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0036] In existing rotor assembly processes, the magnet is installed onto the isolator after being secured to the rotor yoke with screws. This assembly method is difficult. Furthermore, during high-speed rotation of the rotor assembly, the magnet is highly likely to detach from the rotor yoke, leading to low reliability. For example, if the magnet is not axially restrained in the rotor yoke, it may fly off along the axial direction of the rotor yoke when the rotor assembly operates at high speed or when the fixing between the magnet and the rotor yoke fails.

[0037] This application provides a rotor assembly. Referring to Figures 1 to 5, Figure 1 is a structural schematic diagram of an embodiment of the rotor assembly provided in this application; Figure 2 is a structural schematic diagram of an embodiment of the rotor yoke provided in this application; Figure 3 is a structural schematic diagram of another embodiment of the rotor yoke provided in this application; Figure 4 is a structural schematic diagram of an embodiment of the rotor yoke of the embodiment of Figure 3 with magnets provided; and Figure 5 is a structural schematic diagram of an embodiment of the collar provided in this application. The rotor assembly 200 includes a rotor yoke 210, a plurality of magnets 220, and a limiting ring 230.

[0038] The rotor yoke 210, also known as the rotor core, primarily functions to transmit magnetic flux and support and fix the magnets 220. Additionally, it acts as a motor shaft to transmit torque. Specifically, the rotor yoke 210 is an annular shape. The first side of the rotor yoke 210 (not shown in the figure) has multiple first mounting slots 213 spaced apart along its circumferential Z-axis. Multiple magnets 220 are respectively installed within these slots. Due to the spaced arrangement of the slots, even if the fixing effect between the magnets 220 and the rotor yoke fails, adjacent magnets 220 will not attract each other along the tangential direction of the rotor yoke's circumferential Z-axis. Specifically, magnets 220 of different polarities are arranged alternately; for example, the multiple magnets 220 are arranged sequentially as N-pole, S-pole, N-pole, S-pole along the circumferential Z-axis of the rotor yoke 210. The first side is configured to face the stator assembly 100. For example, the first side can be the inner side of the rotor yoke 210, or the first side can be the outer side opposite to the inner side of the rotor yoke 210, which is not limited here. The rotor yoke 210 is made of a ferromagnetic material with high magnetic permeability, such as silicon steel sheet, low carbon steel, etc., which is not limited here.

[0039] To limit the movement of the magnet 220 relative to the rotor yoke 210 along the axial X direction, a limiting ring 230 is provided on the first side surface and located at the end of the magnet 220 along the axial X direction of the rotor yoke 210. The limiting ring 230 can be located at any end of the magnet 220 along the axial X direction of the rotor yoke 210; this is not limited here.

[0040] The rotor assembly 200 of this application includes a rotor yoke 210, a plurality of magnets 220, and a limiting ring 230. The rotor yoke 210 has a plurality of first mounting grooves 213 spaced at Z-intervals along its first side facing the stator assembly 100 for mounting the magnets 220. This means the rotor yoke 210 can directly index and position the magnets 220 without requiring additional separators. This reduces the steps involved in fixing additional separators to the rotor yoke 210 during rotor assembly 200 assembly, thus lowering the assembly difficulty and reducing the overall weight of the rotor assembly 200. Cost reduction; furthermore, the positioning of the magnet 220 in the circumferential Z direction of the rotor yoke 210 can be accomplished by the first mounting groove 213, enabling high-precision positioning of the magnet 220; in addition, the rotor assembly 200 also provides a limiting ring 230 on the first side and at the end of the magnet 220 in the axial X direction of the rotor yoke 210, so that the limiting ring 230 limits the magnet 220 in the axial X direction of the rotor yoke 210, which can prevent the magnet 220 from flying away from the rotor yoke 210 in the axial X direction, thereby enhancing the reliability of the rotor assembly 200 and thus enhancing the reliability of the motor assembly using the rotor assembly 200 provided in this application.

[0041] In one embodiment, to enhance the limiting effect of the limiting ring 230 on the magnet 220, the limiting ring 230 protrudes from the magnet 220 in a direction away from the first side along the radial direction Y of the rotor yoke 210. Here, the direction away from the first side refers to the direction in which the first side of the rotor yoke 210 is away from the center of the rotor yoke 210. That is, the dimension of the limiting ring 230 in the radial direction Y is larger than the dimension of the magnet 220 in the radial direction Y. Therefore, the limiting ring 230 can completely cover the end of the magnet 220 in the radial direction Y, increasing the contact area between the limiting ring 230 and the end of the magnet 220, thus enhancing the limiting effect of the limiting ring 230. Furthermore, the fact that the limiting ring 230 can completely cover the end of the magnet 220 also reduces magnetic leakage from the magnet 220.

[0042] In one embodiment, the rotor assembly 200 includes two limiting rings 230, which are respectively disposed at the ends of the magnet 220 along the axial direction X of the rotor yoke 210. Understandably, along the axial direction X of the rotor yoke 210, the magnet 220 is located between the two limiting rings 230. When the magnet 220 moves relative to the rotor yoke 210 along the axial direction X, it is limited by the limiting rings 230 in the direction of movement. Even if the fixing effect between the magnet 220 and the first mounting groove 213 fails, no axial movement will occur, thus enhancing the limiting effect on the magnet 220. Furthermore, the limiting rings 230 can also prevent the magnet 220 from being exposed and prevent foreign objects, especially ferromagnetic materials, from being attracted into the interior of the rotor assembly 200, thus playing a role in preventing foreign objects from entering.

[0043] In one embodiment, the limiting ring 230 includes at least one sleeve ring 231, which is sleeved on the first side and located at the end of the magnet 220 along the axial direction X of the rotor yoke 210. The sleeve ring 231 abuts against the end of the magnet 220 along the axial direction, thereby restricting the movement of the magnet 220 relative to the rotor yoke 210 along the rotor axial direction toward the side where the sleeve ring 231 is located. Furthermore, the abutment between the sleeve ring 231 and the end of the magnet 220 also reduces magnetic leakage from the magnet 220.

[0044] In one embodiment, the limiting ring 230 includes two collars 231, which are sleeved on the first side and located at the two ends of the magnet 220 along the axial direction of the rotor yoke 210. Both collars 231 abut against the ends of the magnet 220 along the axial direction X of the rotor yoke 210. In this embodiment, the two collars 231 restrict the movement of the magnet 220 relative to the rotor yoke 210 along the axial direction X towards the collars 231, preventing axial movement even if the fixing effect between the magnet 220 and the first mounting groove 213 fails. Furthermore, the collars 231 also prevent foreign objects, especially ferromagnetic materials, from being attracted into the rotor assembly 200, thus acting as a foreign object preventer. Further, the abutment between the collars 231 and the ends of the magnet 220 reduces magnetic leakage from the magnet 220.

[0045] In one embodiment, the collar 231 can be a plastic collar, a nylon collar, or other collar with magnetic isolation function, and is not limited thereto.

[0046] In one embodiment, along the axial direction X of the rotor yoke 210, a first protrusion 211 and at least one second protrusion 212 are formed at intervals on a first side surface. A first mounting groove 213 is provided on the first protrusion 211, and the second protrusion 212 serves as a limiting ring 230 located at the end of the magnet 220 on the axial direction X of the rotor yoke 210. The first protrusion 211 and the second protrusion 212 can be understood as protruding away from the first side surface and towards the center of the rotor yoke 210 or away from the center along the radial direction Y of the rotor yoke 210. Specifically, if the first side surface is located on the inner side surface of the rotor yoke 210, the first protrusion 211 and the second protrusion 212 correspondingly protrude towards the center along the radial direction Y of the rotor yoke 210; if the first side surface is located on the outer side surface opposite to the inner side surface of the rotor yoke 210, the first protrusion 211 and the second protrusion 212 correspondingly protrude away from the center along the radial direction Y of the rotor yoke 210. Along the axial direction X of the rotor yoke 210, the first protrusion 211 is located at the center of the first side surface, and the second protrusion 212 is located on either side of the first protrusion 211. The center can be the centerline of the rotor yoke 210 along its axial direction, or the center can be a position close to the centerline of the rotor yoke 210 along its axial direction, which is not limited here.

[0047] In this embodiment, the first side of the rotor yoke 210 forms a first protrusion 211 and a second protrusion 212 spaced apart. A first mounting groove 213 is provided on the first protrusion 211, and the second protrusion 212 serves as a limiting ring 230. That is, by machining the first protrusion 211 and the second protrusion 212 on the first side of the rotor yoke 210, the rotor yoke 210 can achieve indexing, positioning and limiting of the magnet 220 without the need for additional isolation members. This reduces the assembly steps of the rotor assembly 200, lowers the assembly difficulty of the rotor assembly, and also reduces the cost of the rotor assembly 200.

[0048] In one embodiment, along the axial direction X of the rotor yoke 210, a second protrusion 212, a first protrusion 211, and a second protrusion 212 are sequentially formed on the first side of the rotor yoke 210. That is, the two second protrusions 212 are respectively located at both ends of the magnet 220 in the axial direction of the rotor yoke 210, and both second protrusions 212 axially limit the magnet 220.

[0049] In one embodiment, a collar 231 is provided on the second protrusion 212. That is, by adding a collar 231 to the second protrusion 212, the collar 231 can reduce the gap between the second protrusion 212 and the magnet 220, reduce the magnetic leakage of the magnet 220, and at the same time make it easier to install the magnet 220 into the first mounting groove 213.

[0050] In one embodiment, along the radial direction Y of the rotor yoke 210, the size of the second protrusion 212 is smaller than the size of the first protrusion 211. That is, the first side of the rotor yoke 210 in this embodiment has rings with different radial dimensions, and the radial dimension of the middle ring is larger than that of the small rings on the two sides or one side. When machining the rotor yoke 210, it is only necessary to machine the small rings on both sides of the rotor yoke 210 near the edge to obtain the middle ring and the small rings. Then, the first mounting groove 213 is machined into the middle ring to complete the machining of the rotor yoke 210. In this embodiment, the magnet 220 is limited in the axial direction X of the rotor yoke 210 by means of the collar 231. The machining method of the rotor yoke 210 in this embodiment is simple and can reduce the machining cost of the rotor yoke 210.

[0051] For example, the rotor assembly 200 includes 70 magnets 220. When processing the rotor yoke 210 in this embodiment, the first side of the rotor yoke 210 can first be processed into a large ring. Then, starting from the edge of the large ring, a small ring with a radial dimension smaller than the large ring is processed into the large ring as a second protrusion 212. A middle ring is reserved as a first protrusion 211. Then, the middle ring is processed into a flat-bottomed groove along the outer diameter of the small ring as a first mounting groove 213. Thus, it can be seen that the processing steps of the rotor yoke 210 in this embodiment are relatively simple, the processing accuracy is high, and the processing cost of the rotor yoke 210 can be reduced.

[0052] In one embodiment, the size of the first mounting groove 213 along the radial direction Y of the rotor yoke 210 is larger than the size of the magnet 220. This can be understood as the magnet 220 being able to be completely embedded in the first mounting groove 213 along the radial direction Y of the rotor yoke 210. Alternatively, it can be understood that the distance between the surface of the protrusion and the surface of the recess in the first mounting groove 213 along the radial direction Y of the rotor yoke 210 is greater than the size of the magnet 220 in the radial direction of the rotor yoke 210. In this embodiment, the larger size of the first mounting groove 213 in the radial direction of the rotor yoke 210 compared to the size of the magnet 220 enhances the positioning effect between the magnet 220 and the rotor yoke 210.

[0053] In one embodiment, the magnet 220 is attached to the bottom wall of the first mounting groove 213, which can reduce the installation difficulty of the magnet 220, thereby reducing the assembly difficulty of the rotor assembly 200.

[0054] In one embodiment, the magnet 220 is made of permanent magnet materials such as neodymium iron boron, samarium cobalt, and ferrite, or the magnet 220 is electrically excited, which is not limited here.

[0055] In one embodiment, the first mounting groove 213 is a through groove along the axial direction X of the rotor yoke 210. That is, the first mounting groove 213 has no protrusions along the axial direction X of the rotor yoke 210, and the protrusions of the first mounting groove 213 are provided along the circumferential direction Z of the rotor yoke 210 at intervals from the recesses of the first mounting groove 213. The first mounting groove 213 in this embodiment is simple to process, which can reduce processing costs; and the magnet 220 can be installed by simply pushing it flat, which can reduce the installation difficulty of the magnet 220.

[0056] In one embodiment, the bottom wall dimension of the first mounting groove 213 is the same as that of the second protrusion 212 along the radial direction Y of the rotor yoke 210. When machining the first mounting groove 213 on the rotor yoke 210 of this embodiment, only the first protrusion 211 needs to be machined axially. The first mounting groove 213 of this embodiment can reduce the machining difficulty of the rotor yoke 210, reduce machining steps, and lower machining costs.

[0057] This application provides a motor assembly 10. Referring to Figures 6 and 7, Figure 6 is a structural schematic diagram of an embodiment of the motor assembly provided in this application; Figure 7 is a cross-sectional schematic diagram of an embodiment of the motor assembly of Figure 6. The motor assembly 10 includes a rotor assembly 200 and a stator assembly 100, and the stator assembly 100 and the rotor assembly 200 are magnetically coupled. The rotor assembly 200 can be any one of the rotor assembly 200 embodiments described above, and is not limited herein.

[0058] In one embodiment, the motor assembly 10 further includes a bearing 300, which includes an outer ring 310 and an inner ring 320, wherein the outer ring 310 is located outside the inner ring 320, and the outer ring 310 and inner ring 320 are coaxially arranged. The stator assembly 100 and the rotor assembly 200 are connected via the bearing 300. For example, the rotor assembly 200 is sleeved outside the stator assembly 100, and the stator assembly 100 is connected to the inner ring 320 of the bearing 300 along the axial direction of the bearing 300, while the rotor assembly 200 is connected to the outer ring 310 of the bearing 300 along the axial direction. Alternatively, the stator assembly 100 is sleeved outside the rotor assembly 200, and the rotor assembly 200 is connected to the inner ring 320 of the bearing 300 along the axial direction of the bearing 300, while the stator assembly 100 is connected to the outer ring 310 of the bearing 300 along the axial direction. The bearing 300 can be a crossed roller bearing or a double-row angular contact bearing, and is not limited thereto. Bearing 300 can withstand radial and axial loads, as well as a certain bending moment.

[0059] In one embodiment, the motor assembly 10 is a hollow motor, with its stator assembly 100 serving as a fixed component, fixed to the outer ring 310 of the bearing 300. The rotor assembly 200 serves as a rotating component, fixed to the inner ring 320 of the bearing 300, which can improve the stiffness of the rotor yoke 210.

[0060] In one embodiment, the outer ring 310 of the bearing 300 protrudes beyond the inner ring 320 towards the stator assembly 100, and a second mounting groove (not shown) is provided on the end face of the outer ring 310 facing the stator assembly 100. The stator assembly 100 is at least partially disposed within the second mounting groove and spaced apart from the inner ring 320. A third mounting groove (not shown) is provided on the side of the inner ring 320 facing the rotor assembly 200. The rotor assembly 200 is fitted with the stop of the third mounting groove to improve the coaxiality of the inner ring 320 and the rotor assembly 200. The rotor assemblies 200 can be connected to each other using studs.

[0061] In one embodiment, the size of the stator assembly 100 is smaller than the size of the rotor assembly 200 along the axial direction X of the rotor yoke or along the axial direction of the bearing 300.

[0062] This application provides an electronic device (not shown in the figure) that includes a motor assembly 10. The motor assembly 10 can be any of the motor assemblies described in the above embodiments, and is not limited thereto. The electronic device can be a computed tomography (CT) scanner, a robotic arm, a collaborative robot, etc., and is not limited thereto.

[0063] In one embodiment, the electronic device is a CT scanner. When the motor assembly 10 is applied to the CT scanner, the rotor assembly 200 operates at a relatively low speed. According to electromagnetic calculations, the centrifugal force of the rotor assembly 200 during operation is less than the attractive force between the magnet 220 and the rotor yoke 210, while the attractive force between the magnet 220 and the rotor yoke 210 is greater than the centrifugal force during the operation of the rotor yoke 210. Therefore, even if the adhesive between the magnet 220 and the rotor yoke 210 fails, the magnet 220 will not fly off radially (Y) along the rotor yoke 210. Simultaneously, due to the multiple spaced first mounting grooves 213 on the first side of the rotor yoke 210, adjacent magnets 220 will not be attracted together circumferentially (Z) along the rotor yoke 210. Furthermore, due to the presence of the limiting ring 230, the magnet 220 will not move axially (X) along the rotor yoke 210. Therefore, the rotor assembly 200 provided in this application can eliminate the greatest safety hazard of the motor assembly 10 in the CT scanner and improve the reliability of the CT scanner's operation.

[0064] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A rotor assembly, wherein, The rotor assembly includes: The rotor yoke has a first side surface provided with a plurality of first mounting slots spaced circumferentially along the rotor yoke; the first side surface is configured to face the stator assembly. Multiple magnets are respectively installed in the multiple first mounting slots; A limiting ring is disposed on the first side and located at the end of the magnet in the axial direction of the rotor yoke to limit the movement of the magnet in the axial direction relative to the rotor yoke.

2. The rotor assembly of claim 1, wherein, The limiting ring includes at least one ring, which is sleeved on the first side and located at the end of the magnet in the axial direction of the rotor yoke; the ring abuts against the end of the magnet along the axial direction.

3. The rotor assembly of claim 1, wherein, Along the axial direction of the rotor yoke, the first side surface forms a first protrusion and at least one second protrusion spaced apart; the first mounting groove is provided on the first protrusion, and the second protrusion serves as the limiting ring located at the end of the magnet in the axial direction of the rotor yoke.

4. The rotor assembly of claim 1, wherein, The rotor assembly includes two limiting rings, which are respectively disposed at the ends of the magnet in the axial direction.

5. The rotor assembly of claim 3, wherein, The rotor assembly also includes a collar disposed on the second protrusion.

6. The rotor assembly of claim 1, wherein, Along the radial direction of the rotor yoke, the limiting ring protrudes from the magnet in a direction away from the first side.

7. The rotor assembly of claim 3, wherein, Along the radial direction of the rotor yoke, the size of the second protrusion is smaller than the size of the first protrusion.

8. The rotor assembly of any one of claims 1 to 7, wherein, The magnet is attached to the bottom wall of the first mounting slot.

9. A motor assembly, wherein, include: The rotor assembly according to any one of claims 1 to 8; The stator assembly is magnetically coupled to the rotor assembly.

10. The motor assembly according to claim 9, wherein, The motor assembly also includes: The bearing, one of the stator assembly and the rotor assembly is connected to the inner ring of the bearing along the axial direction of the bearing, and the other of the stator assembly and the rotor assembly is connected to the outer ring of the bearing along the axial direction of the bearing.

11. The motor assembly according to claim 10, wherein, The stator assembly is fitted over the rotor assembly; the stator assembly is connected to the outer ring, and the rotor assembly is connected to the inner ring.

12. The motor assembly according to claim 11, wherein, The outer ring protrudes from the inner ring toward the stator assembly, and a second mounting groove is provided on the end face of the outer ring toward the stator assembly. The stator assembly is at least partially disposed in the second mounting groove and is spaced apart from the inner ring. The inner ring has a third mounting groove on the side facing the rotor assembly, and the rotor assembly is fitted with the stop of the third mounting groove.

13. An electronic device, wherein, include: The motor assembly according to any one of claims 9-12.

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