Rotor assembly and electric machine
By optimizing the magnet layout and structural design in the rotor assembly and increasing the magnet volume, the technical problem of improving motor power density was solved, resulting in higher air gap magnetic flux density and output torque.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG MIDEA ELECTRIC CO LTD
- Filing Date
- 2024-12-31
- Publication Date
- 2026-07-10
AI Technical Summary
Existing motors have limitations in increasing power density, mainly due to the limitations in improving air gap magnetic flux density, especially the influence of magnet volume.
A rotor assembly is designed by setting first and second magnets of different widths and increasing their axial length, combined with the protective and support structure of connecting ribs and fixing frames, to optimize the layout of the magnet assembly to increase its volume.
The amount of magnets used and the air gap magnetic flux density were increased, thereby improving the power density of the motor.
Smart Images
Figure CN122371540A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of motor technology, and in particular to a rotor assembly and a motor. Background Technology
[0002] An electric motor consists of a rotor assembly, a stator assembly, and a shaft. The stator assembly encloses the rotor assembly, and the rotor assembly encloses the shaft. When the motor is energized, the rotor assembly rotates under the influence of a magnetic field, thereby driving the shaft to rotate.
[0003] Nowadays, various industries have increasingly higher requirements for motors, namely, the need for motors with higher power density. The power density of a motor is mainly affected by its air gap magnetic flux density, so how to improve the air gap magnetic flux density of a motor is a key issue that needs to be addressed. Summary of the Invention
[0004] This disclosure provides a rotor assembly and a motor that can solve the technical problems existing in the related art. The technical solutions of the rotor assembly and the motor are as follows.
[0005] In a first aspect, this disclosure provides a rotor assembly, the rotor assembly including a rotor core and a plurality of magnet assemblies;
[0006] The rotor core includes a core yoke and multiple core poles. The core yoke is annular, and the multiple core poles are fixed to the core yoke circumferentially. Each magnet assembly is fixed between two adjacent core poles.
[0007] The magnet assembly includes a first magnet and a second magnet. The width of the first magnet along the tangential direction is greater than the width of the second magnet along the tangential direction. The second magnet is located between the first magnet and the core yoke. The intersection of the extension lines of the sidewalls of two adjacent first magnets is located at the core pole. The magnetization directions of the first magnet and the second magnet are the same, and the axes of the first magnet and the second magnet coincide.
[0008] The axial length of the first magnet and / or the axial length of the second magnet is greater than the axial length of the rotor core.
[0009] In one possible implementation, the minimum tangential distance between the sidewalls of two adjacent first magnets is 0.8 mm to 1.5 mm.
[0010] In one possible implementation, the distance between the second magnet and the iron core yoke is 0-1 mm.
[0011] In one possible implementation, the rotor core further has a first connecting rib, the two ends of which are respectively connected to two adjacent core poles, and the magnet assembly is located between the first connecting rib and the core yoke.
[0012] The first connecting rib has a magnetic resistance groove on the side facing the magnet assembly, and there is a gap between the magnetic resistance groove and the magnet assembly.
[0013] In one possible implementation, let the maximum radial thickness of the first connecting rib be D, then 0.2mm ≤ D ≤ 0.5mm.
[0014] In one possible implementation, the rotor core further includes a second connecting rib, with each of the second connecting ribs connected at both ends to the core yoke and the core pole, respectively.
[0015] There are multiple magnetic steel assemblies between two adjacent second connecting ribs.
[0016] In one possible implementation, the tangential width of the first connecting rib is L, then 0.5mm≤L≤1.2mm.
[0017] In one possible implementation, the sidewall of the core yoke has a top magnetic post that protrudes radially.
[0018] The top magnetic column is completely in contact with the second magnet.
[0019] In one possible implementation, the radial height of the top magnetic post is 0.5 mm to 1 mm.
[0020] In one possible implementation, the rotor assembly further includes two mounting brackets;
[0021] The fixing frame is ring-shaped, and both ends of the magnet assembly are fixed to the fixing frame. The fixing frame is fixedly connected to the iron core pole.
[0022] In one possible implementation, the mounting bracket has a plurality of circumferentially arranged mounting holes, and the magnet assembly is fixedly connected to the sidewall of the mounting holes.
[0023] In one possible implementation, the iron core pole has positioning grooves at both ends, and the fixing frame has positioning protrusions, which are fixed in the positioning grooves.
[0024] In a second aspect, this disclosure provides an electric motor, the electric motor including a stator assembly, a shaft and a rotor assembly as described in any of the first aspects;
[0025] The rotor assembly has a core yoke ring that fits around the shaft, and the stator assembly surrounds the rotor assembly.
[0026] The technical solution provided in this disclosure includes at least the following beneficial effects:
[0027] This disclosure provides a rotor assembly where, because the rotor core is annular, the space between adjacent core poles decreases closer to the core yoke. Therefore, by setting the widths of the first and second magnets to be different, the space between adjacent core yokes can be fully utilized, resulting in a larger volume for the magnet assembly. Furthermore, the axial length of the first magnet and / or the second magnet is greater than the axial length of the rotor core, further increasing the volume of the magnet assembly. This increases the amount of magnets used, thereby improving the air gap magnetic flux density of the motor and thus increasing the power density of the motor.
[0028] 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
[0029] 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. In the drawings:
[0030] Figure 1 This is a schematic diagram of the structure of an electric motor shown in an embodiment of this disclosure;
[0031] Figure 2 This is an exploded view of an electric motor shown in an embodiment of this disclosure;
[0032] Figure 3 This is a cross-sectional view of a rotor assembly shown in an embodiment of this disclosure;
[0033] Figure 4 This is a schematic diagram of the structure of a rotor assembly shown in an embodiment of this disclosure;
[0034] Figure 5 This is a schematic diagram of the structure of a rotor core shown in an embodiment of this disclosure;
[0035] Figure 6 This is a partial structural schematic diagram of a rotor core according to an embodiment of the present disclosure;
[0036] Figure 7 This is a partial structural schematic diagram of a rotor core according to an embodiment of the present disclosure;
[0037] Figure 8 This is a cross-sectional view of a rotor assembly shown in an embodiment of this disclosure;
[0038] Figure 9 This is a partial structural schematic diagram of a rotor core according to an embodiment of the present disclosure;
[0039] Figure 10 This is a schematic diagram of the structure of a rotor assembly shown in an embodiment of this disclosure;
[0040] Figure 11 This is a schematic diagram of the structure of a fixing frame shown in an embodiment of this disclosure;
[0041] Figure 12 This is a schematic diagram of the structure of a rotor core shown in an embodiment of this disclosure;
[0042] Figure 13 This is a schematic diagram of the structure of an electric motor shown in an embodiment of this disclosure.
[0043] Legend:
[0044] 1. Rotor core;
[0045] 11. Iron core yoke; 111. Top magnetic column;
[0046] 12. Iron core pole; 121. Positioning groove;
[0047] 13. First connecting rib; 131. Magnetic resistance groove;
[0048] 14. Second connecting bar;
[0049] 2. Magnet assembly; 21. First magnet; 211. First sidewall; 212. Second sidewall; 22. Second magnet;
[0050] 3. Fixture; 31. Mounting hole; 32. Positioning protrusion;
[0051] 4. Stator core; 41. Stator groove;
[0052] 5. Stator windings;
[0053] 100. Stator assembly;
[0054] 200. Shaft;
[0055] 300. Rotor assembly.
[0056] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0057] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings.
[0058] The terminology used in the embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used herein should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “a” or “one,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected,” “linked,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.
[0059] like Figure 1 As shown, the motor includes a stator assembly 100, a shaft 200, and a rotor assembly 300. The stator assembly 100 surrounds the rotor assembly 300, and the rotor assembly 300 surrounds the shaft 200. When the motor is energized, the rotor assembly 300 can rotate under the influence of the magnetic field, thereby driving the shaft 200 to rotate.
[0060] With the increasing demands on motors across various industries, higher power density is now required. The power density of a motor is primarily influenced by its air gap magnetic flux density. This air gap magnetic flux density is affected by the volume of the magnets within the motor; a larger magnet volume results in a higher air gap magnetic flux density. Therefore, increasing the volume of the magnets is a key issue that needs to be addressed.
[0061] This disclosure provides a rotor assembly, such as... Figure 2 and Figure 3 As shown, the rotor assembly includes a rotor core 1 and multiple magnet assemblies 2. The rotor core 1 includes a core yoke 11 and multiple core poles 12. The core yoke 11 is annular, and the multiple core poles 12 are fixed circumferentially to the core yoke 11. Each magnet assembly 2 is fixed between two adjacent core poles 12. The magnet assembly 2 includes a first magnet 21 and a second magnet 22. The tangential width of the first magnet 21 is greater than the tangential width of the second magnet 22, and the second magnet 22 is located between the first magnet 21 and the core yoke 11. The intersection of the extension lines of the sidewalls of two adjacent first magnets 21 is located at the core pole 12. The magnetization directions of the first magnet 21 and the second magnet 22 are the same, and the axes of the first magnet 21 and the second magnet 22 coincide. Figure 4 As shown, the axial length of the first magnet 21 and / or the axial length of the second magnet 22 are greater than the axial length of the rotor core 1.
[0062] The first magnet 21 and the second magnet 22 can be made of the same or different materials. Both the first magnet 21 and the second magnet 22 can be rectangular.
[0063] like Figure 2 The first magnet 21 has a first sidewall 211 and a second sidewall 212, which are opposite to each other and extend radially along the rotor core 1. The extensions of the first sidewall 211 of one first magnet 21 and the second sidewall 212 of an adjacent magnet intersect at point A, and the first sidewall 211 and the second sidewall 212 are adjacent. If the magnet assembly 2 only includes the first magnet 21, then to avoid interference between adjacent first magnets 21, the first magnet 21 can only extend from the edge of the rotor core 1 to point A. This makes it difficult to fully utilize the space between point A and the core yoke 11, which is detrimental to increasing the volume of the magnet assembly 2.
[0064] A groove is formed between two adjacent iron core poles 12, and the shape of the groove is approximately the same as that of the magnet assembly 2.
[0065] The magnet assembly 2 can be connected to the iron core pole 12 by adhesive bonding.
[0066] There is a magnetic flux path between the rotor assembly 300 and the stator assembly 100. The magnetic lines of force pass sequentially through the iron core yoke 11, the iron core pole 12, the magnet assembly 2, the other iron core pole 12, the stator assembly, and then return to the iron core yoke 11.
[0067] The technical solution provided in this disclosure, since the rotor core 1 is annular, has a smaller space between two adjacent core poles 12 closer to the core yoke 11. Therefore, by setting the widths of the first magnet 21 and the second magnet 22 to be different, the space between two adjacent core yokes 11 can be fully utilized, resulting in a larger volume for the magnet assembly 2. Simultaneously, the axial length of the first magnet 21 and / or the axial length of the second magnet 22 is greater than the axial length of the rotor core 1, further increasing the volume of the magnet assembly 2. This increases the amount of magnets used, thereby improving the air gap magnetic flux density of the motor and thus contributing to increased power density.
[0068] In some examples, such as Figure 4 As shown, the first magnet 21 and the second magnet 22 have the same axial length, and their ends are aligned. This allows the magnetic fields on the first magnet and the second magnet 22 to be superimposed, which is beneficial for improving the power density of the motor.
[0069] In some examples, the minimum tangential distance between the sidewalls of two adjacent first magnets 21 is 0.8mm-1.5mm. This not only avoids interference between adjacent first magnets 21, but also makes full use of the space between adjacent iron core yokes 11, which helps to increase the volume of the magnet assembly 2 and thus improve the power density of the motor.
[0070] In some examples, the distance between the second magnet 22 and the iron core yoke 11 can be 0-1 mm. This allows for full utilization of the space between adjacent iron core yokes 11. It also helps to increase the volume of the magnet assembly 2, thereby increasing the power density of the motor.
[0071] In some examples, such as Figure 4 and Figure 5 As shown, the rotor core 1 also has a first connecting rib 13. The two ends of the first connecting rib 13 are respectively connected to two adjacent core poles 12, and the magnet assembly 2 is located between the first connecting rib 13 and the core yoke 11. Since magnets are relatively brittle and easily damaged, the first connecting rib 13 surrounding the outer wall of the magnet assembly 2 can protect the magnet assembly. Furthermore, the first connecting rib 13 can also strengthen the connection strength between the core poles 12.
[0072] Because the first connecting rib 13 has magnetic conductivity, leakage magnetic field will be formed on the first connecting rib 13, that is, magnetic flux lines will form a magnetic flux loop between the first magnet 21 and the first connecting rib 13 (e.g., Figure 6 As shown by the dashed arrow in the image, Figure 6 for Figure 3 (A partially enlarged view). This reduces the magnetic field strength between the rotor assembly 300 and the stator assembly 100, thus affecting the motor's output torque. For example... Figure 7 As shown, in order to reduce magnetic leakage on the first connecting rib 13, the first connecting rib 13 has a magnetic resistance groove 131 on the side facing the magnet assembly 2, and there is a gap between the magnetic resistance groove 131 and the magnet assembly 2. Figure 7 for Figure 5 (Partial enlarged view). Due to the high magnetic reluctance of air, only a few magnetic lines of force pass through the first connecting rib 13. In this way, the first connecting rib 13 can both protect the first magnet 21 and not have a significant impact on the output torque of the motor.
[0073] In some examples, such as Figure 7 As shown, let D be the maximum radial thickness of the first connecting rib 13, then 0.2mm ≤ D ≤ 0.5mm. In this way, the first connecting rib 13 can both protect the first magnet 21 and not have a significant impact on the output torque of the motor.
[0074] If D is too small, the first connecting rib 13 will be too thin to protect the first magnet 21, and the connection strength between the iron core poles 12 will be low.
[0075] If D is too large, it will result in more leakage flux on the first connecting rib 13, thus affecting the output torque of the motor. In addition, an excessively large D will also result in less space for accommodating the magnet assembly 2, which is not conducive to increasing the volume of the magnet assembly 2.
[0076] In some examples, such as Figure 8 and Figure 9 As shown ( Figure 9 for Figure 5 (Partial enlarged view) The rotor core 1 also includes a second connecting rib 14, with the two ends of each second connecting rib 14 connected to the core yoke 11 and the core pole 12, respectively.
[0077] In related technologies, the number of second connecting ribs 14 is the same as the number of iron core poles 12. Each iron core pole 12 is connected to the iron core yoke 11 through the second connecting rib 14. The second connecting rib 14 is magnetically conductive, thus leakage magnetic flux is formed on the second connecting rib 14. That is, a portion of the magnetic field lines on the second magnet 22 will reach the second connecting rib 14 through the iron core pole 12, then reach the adjacent second connecting rib 14 through the iron core yoke 11, and finally return to the second magnet 22 through the adjacent iron core pole 12 (e.g., ...). Figure 8 (As shown by the dashed arrow in the diagram). This will reduce the magnetic field strength between the rotor assembly 300 and the stator assembly 100, thereby affecting the motor's output torque.
[0078] To reduce magnetic leakage on the second connecting rib 14, this embodiment reduces the number of second connecting ribs 14 to fewer than the number of core poles 12, resulting in multiple magnet assemblies 2 between adjacent second connecting ribs 14. This creates gaps between some core poles 12 and the core yoke 11, resulting in greater magnetic reluctance between them, thereby reducing the distribution of magnetic flux lines and thus reducing magnetic leakage. This is beneficial for improving the output torque of the motor.
[0079] The multiple second connecting ribs 14 are evenly distributed along the axial direction, and the number of magnet assemblies 2 between each pair of adjacent second connecting ribs 14 is the same. This ensures that the core yoke 11 and the core pole 12 are subjected to more uniform force, guaranteeing a high connection strength between the core yoke 11 and the core pole 12. It is understood that although some core poles 12 are not connected to the core yoke 11 by the second connecting ribs 14, the multiple core poles 12 are connected as a single structure by the first connecting ribs 13. Therefore, the combined action of the first connecting ribs 13 and the second connecting ribs 14 ensures the fixation of each core pole 12.
[0080] For example, such as Figure 8 As shown, there can be two magnet assemblies 2 between each two adjacent second connecting ribs 14. If there are more magnet assemblies 2 between the second connecting ribs 14, it indicates that there are fewer second connecting ribs 14. This will reduce the connection strength between multiple iron core poles 12 and iron core yokes 11, making the rotor assembly more prone to damage.
[0081] In some examples, such as Figure 9 As shown, the tangential width of the first connecting rib 13 is L, so 0.5mm ≤ L ≤ 1.2mm. This ensures both high connection strength between the multiple core poles 12 and the core yoke 11, and reduces magnetic leakage. If L is too large, it will result in less space for the magnet assembly 2 and more magnetic leakage. If L is too small, the connection strength between the multiple core poles 12 and the core yoke 11 will be poor.
[0082] In some examples, such as Figure 8 As shown, the second magnet 22 abuts against the iron core yoke 11. The iron core yoke 11 is annular, and the second magnet 22 is rectangular. To increase the contact area between the iron core yoke 11 and the second magnet 22, as shown... Figure 9 As shown, the sidewall of the core yoke 11 has a top magnetic post 111, which protrudes radially. The sidewall of the top magnetic post 111 facing the second magnet 22 is completely in contact with the second magnet 22, allowing the top magnetic post 111 to support the second magnet 22. This increases the contact area between the core yoke 11 and the second magnet 22, strengthening the connection between the second magnet 22 and the rotor core 1, thus making the rotor assembly less prone to damage.
[0083] For example, the tangential width of the top magnetic post 111 is less than or equal to the tangential width of the second magnet 22.
[0084] In some examples, the radial height of the top magnetic post 111 can be 0.5mm-1mm. Since the main function of the top magnetic post 111 is to support the second magnet 21, thereby increasing the contact area between the core yoke 11 and the second magnet 22, the height of the top magnetic post 111 does not need to be too high. If the height of the top magnetic post 111 is too large, it will also reduce the space for accommodating the magnet assembly 2, which is not conducive to increasing the volume of the magnet assembly 2.
[0085] To enhance the connection strength between the rotor core 1 and the magnet assembly 2, this embodiment of the present disclosure also provides a fixing frame 3, and both the rotor core 1 and the magnet assembly 2 are connected to the fixing frame 3. The implementation of the fixing frame 3 will be described below by way of example.
[0086] In some examples, such as Figure 10As shown, the rotor assembly also includes two mounting brackets 3. The mounting brackets 3 are annular, and both ends of the magnet assembly 2 are fixed to the mounting brackets 3. The mounting brackets 3 are fixedly connected to the iron core pole 12. Because the axial length of the magnet assembly 2 is greater than the axial length of the rotor iron core 1, part of the magnet assembly 2 is exposed. Since magnets themselves are brittle and easily damaged, the mounting brackets 3 protect the magnet assembly 2. Furthermore, they reduce wind resistance generated during rotation due to gaps between adjacent magnet assemblies 2.
[0087] The axial lengths of the two ends of the magnet assembly 2 extending from the rotor core 1 can be the same, so the axial lengths of the two fixing frames 3 are also the same.
[0088] It can be understood that if the magnet assembly 2 has only one end extending from the rotor core 1, the rotor assembly has only one fixing frame 3.
[0089] In some examples, such as Figure 11 As shown, the mounting bracket 3 has multiple mounting holes 31 arranged circumferentially, and the magnet assembly 2 is fixedly connected to the side wall of the mounting hole 31. The side wall of the magnet assembly 2 can be connected to the side wall of the mounting hole 31 by adhesive bonding.
[0090] In some examples, such as Figure 11 and Figure 12 As shown, the iron core pole 12 has positioning grooves 121 at both ends, and the fixing frame 3 has positioning protrusions 32, which are fixed in the positioning grooves 121. This strengthens the connection between the fixing frame 3 and the iron core pole 12, thereby strengthening the connection between the magnet assembly 2 and the rotor iron core 1.
[0091] In this embodiment, each iron core pole 12 may have a positioning groove 121 at both ends, or some iron core poles 12 may have a positioning groove 121 at both ends. This embodiment does not specifically limit the specific application of this method.
[0092] This disclosure also provides an electric motor, such as... Figure 1 As shown, the motor includes a stator assembly 100, a shaft 200, and the aforementioned rotor assembly 200. The iron core yoke 11 of the rotor assembly 300 is ringed around the shaft 200, and the stator assembly 100 surrounds the rotor assembly 300.
[0093] Among them, such as Figure 13As shown, the stator assembly 100 includes a stator core 4 and a stator winding 5. The stator core 4 has multiple axially distributed stator grooves 41, and each stator winding is located in one stator groove 41. After the windings are energized, a magnetic flux path can be formed between the rotor assembly 200 and the stator assembly 100. The magnetic lines of force pass sequentially through the core yoke 11, the core pole 12, the magnet assembly 2, the other core pole 1, and the stator assembly, and then return to the core yoke 11, thereby enabling the rotor assembly 200 to drive the shaft 200 to rotate under the action of the magnetic field.
[0094] The motor provided in this embodiment has a larger rotor assembly 200 magnet assembly 2, which increases the amount of magnet assembly 2 used. This increases the air gap magnetic flux density between the stator assembly 100 and the rotor assembly 300, thereby increasing the power density of the motor.
[0095] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the protection scope of this disclosure.
Claims
1. A rotor assembly, characterized in that, The rotor assembly includes a rotor core (1) and multiple magnet assemblies (2); The rotor core (1) includes a core yoke (11) and a plurality of core poles (12). The core yoke (11) is annular, and the plurality of core poles (12) are fixed circumferentially to the core yoke (11). Each magnet assembly (2) is fixed between two adjacent core poles (12). The magnet assembly (2) includes a first magnet (21) and a second magnet (22). The width of the first magnet (21) along the tangential direction is greater than the width of the second magnet (22) along the tangential direction. The second magnet (22) is located between the first magnet (21) and the iron core yoke (11). The intersection (A) of the extension lines of the sidewalls of two adjacent first magnets (21) is located at the iron core pole (12). The magnetization directions of the first magnet (21) and the second magnet (22) are the same, and the axes of the first magnet (21) and the second magnet (22) coincide. The axial length of the first magnet (21) and / or the axial length of the second magnet (22) is greater than the axial length of the rotor core (1).
2. The rotor assembly according to claim 1, characterized in that, The minimum tangential distance between the sidewalls of two adjacent first magnets (21) is 0.8mm-1.5mm.
3. The rotor assembly according to claim 1, characterized in that, The rotor core (1) also has a first connecting rib (13), the two ends of the first connecting rib (13) are respectively connected to two adjacent core poles (12), and the magnet assembly (2) is located between the first connecting rib (13) and the core yoke (11); The first connecting rib (13) has a magnetic resistance groove (131) on the side facing the magnet assembly (2), and there is a gap between the magnetic resistance groove (131) and the magnet assembly (2).
4. The rotor assembly according to claim 3, characterized in that, Let the maximum radial thickness of the first connecting rib (13) be D, then 0.2mm≤D≤0.5mm.
5. The rotor assembly according to claim 3, characterized in that, The rotor core (1) further includes a second connecting rib (14), and each of the second connecting ribs (14) is connected at both ends to the core yoke (11) and the core pole (12); The number of the second connecting ribs (14) is less than the number of the core poles (12).
6. The rotor assembly according to claim 5, characterized in that, The tangential width of the first connecting bar (13) is L, then 0.5mm≤L≤1.2mm.
7. The rotor assembly according to any one of claims 1-6, characterized in that, The rotor assembly also includes two mounting brackets (3); The fixing frame (3) is ring-shaped, and the two ends of the magnet assembly (2) are respectively fixed to the fixing frame (3). The fixing frame (3) is fixedly connected to the iron core pole (12).
8. The rotor assembly according to claim 7, characterized in that, The fixing frame (3) has a plurality of mounting holes (31) arranged circumferentially, and the magnet assembly (2) is fixedly connected to the side wall of the mounting holes (31).
9. The rotor assembly according to claim 8, characterized in that, The iron core pole (12) has positioning grooves (121) at both ends, and the fixing frame (3) has positioning protrusions (32), which are fixed in the positioning grooves (121).
10. An electric motor, characterized in that, The motor includes a stator assembly (100), a shaft (200), and a rotor assembly (300) as described in any one of claims 1-9; The core yoke (11) of the rotor assembly (300) is looped around the shaft (200), and the stator assembly (100) surrounds the rotor assembly (300).