Rotor assembly, electric motor and electrical equipment

Abstract

A rotor assembly, an electric motor and electrical equipment. The rotor assembly (10) comprises: a rotor core (1), the rotor core (1) comprising a plurality of core units (11), and each core unit (11) comprising a core body (111); and permanent magnets (2), a plurality of permanent magnets (2) being provided. The plurality of permanent magnets (2) and the plurality of core bodies (111) are alternately arranged in the circumferential direction of the rotor assembly (10). A protrusion (112) is provided on at least one of two sides of each core body (111) in the circumferential direction of the rotor assembly (10), a clearance groove (113) facing a permanent magnet (2) is provided at the joint of at least one protrusion (112) and the core body (111), and the corner of the permanent magnet (2) opposite the clearance groove (113) is right-angled.

Description

Rotor assemblies, motors and electrical equipment

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese patent applications No. 202510021425.9 and 202520029262.4, filed on January 6, 2025, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] In related technologies, the rotors of DC permanent magnet motors for air conditioning fans often adopt an IPM (Interior Permanent Magnet Motor) structure. While this effectively improves the motor's output capacity, it also increases the internal magnetic flux density, leading to a higher risk of demagnetization of the rotor magnets. Sufficient demagnetizing current must be ensured during the design phase to meet the motor's stability requirements under different operating conditions. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a rotor assembly that can improve the demagnetization resistance of permanent magnets.

[0006] This application also proposes an electric motor that includes the rotor assembly described above.

[0007] This application also proposes an electrical device, which includes the aforementioned motor.

[0008] A rotor assembly according to an embodiment of this application includes: a rotor core, the rotor core comprising a plurality of core units, the core unit comprising a core body; and a plurality of permanent magnets, the plurality of permanent magnets and the plurality of core bodies being alternately arranged in the circumferential direction of the rotor assembly. At least one side of the core body along the circumferential direction of the rotor assembly has a protrusion, the permanent magnet being located inside or outside the protrusion along the radial direction of the rotor assembly. At least one connection point between the protrusion and the core body has a clearance groove facing the permanent magnet, the clearance groove extending along the axial direction of the rotor assembly, and the corner between the permanent magnet and the clearance groove being a right angle.

[0009] According to the rotor assembly of this application embodiment, by providing a protrusion on at least one side of the iron core body along the circumferential direction of the rotor assembly, the permanent magnet is located inside or outside the protrusion along the radial direction of the rotor assembly. A clearance groove facing the permanent magnet is provided at the connection between at least one protrusion and the iron core body, extending along the axial direction of the rotor assembly. Simultaneously, the corner opposite the permanent magnet to the clearance groove is a right angle. This improves the demagnetization resistance of the permanent magnet at the corner opposite the clearance groove, reduces local demagnetization of the permanent magnet, and to a certain extent enhances the motor's demagnetization resistance, thereby increasing the motor's demagnetization current. Furthermore, increasing the amount of permanent magnet at the corner opposite the clearance groove can improve the motor's output capacity and efficiency, and can reduce the magnetic bridge width at the protrusion, reducing magnetic leakage. Additionally, the right angle of the side edge of the permanent magnet opposite the clearance groove eliminates the need for the permanent magnet chamfering process, facilitating the processing and dimensional control of the permanent magnet.

[0010] According to some embodiments of this application, the clearance groove includes a first groove located on the core body and a second groove located on the protrusion, the first groove and the second groove being connected.

[0011] According to some embodiments of this application, the protrusion includes a first protrusion, the clearance groove includes a first clearance groove, the first protrusion is provided on at least one side of the iron core body along the circumferential direction of the rotor assembly, the first protrusion is located at the outer end of the iron core body along the radial direction of the rotor assembly, the permanent magnet is located on the radial inner side of the first protrusion, at least one of the first protrusions and the iron core body is provided with the first clearance groove facing the permanent magnet, and the corner opposite the permanent magnet to the first clearance groove is a right angle.

[0012] In some embodiments of this application, the minimum distance between the inner wall of the first clearance groove and the outer wall of the iron core body at the end opposite to the rotor assembly axis is h2, and satisfies: h2≥0.5mm; and / or, the minimum distance between the inner wall of the first clearance groove and the outer wall of the iron core body at the end opposite to the rotor assembly axis is h2, and the distance between the inner wall of the portion of the first clearance groove located on the iron core body and the side wall of the permanent magnet near the iron core body is h1, and satisfies: 0.25≤h1 / h2≤0.65; and / or, the radial length of the permanent magnet is L, and the maximum radial dimension of the first clearance groove is W2, and satisfies: 0.1≤W2 / L≤0.16.

[0013] In some embodiments of this application, the core body is provided with the first protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes first laminations and second laminations that are alternately stacked along the axial direction of the rotor assembly. The first lamination is provided with a first protrusion on one side along the circumferential direction of the rotor assembly, and the second lamination is provided with a second protrusion on one side along the circumferential direction of the rotor assembly. The first protrusion and the second protrusion are located on both sides of the core body along the circumferential direction of the rotor assembly. A plurality of first protrusions form one of the first protrusions, and a plurality of second protrusions form another first protrusion.

[0014] In some embodiments of this application, the first punch and the first protrusion are exactly the same as the second punch and the second protrusion, respectively.

[0015] In some embodiments of this application, the core body is provided with the first protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes a plurality of laminations stacked along the axial direction of the rotor assembly. Each lamination is provided with a first protrusion and a second protrusion on both sides along the circumferential direction of the rotor assembly. The plurality of first protrusions form one of the first protrusions, and the plurality of second protrusions form another first protrusion.

[0016] According to some embodiments of this application, the protrusion includes a second protrusion, the clearance groove includes a second clearance groove, the iron core body is provided with the second protrusion on at least one side of the two sides of the rotor assembly along the circumferential direction, the second protrusion is located at the inner end of the iron core body along the radial direction of the rotor assembly, the permanent magnet is located on the radial outer side of the second protrusion, at least one connection between the second protrusion and the iron core body is provided with the second clearance groove facing the permanent magnet, and the corner opposite to the permanent magnet and the second clearance groove is a right angle.

[0017] In some embodiments of this application, the minimum width of the core body at the outlet of the second clearance groove is w, and satisfies: w≥0.5mm.

[0018] In some embodiments of this application, the core body is provided with the second protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes a first lamination and a second lamination stacked alternately along the axial direction of the rotor assembly. The first lamination is provided with a third protrusion on one side along the circumferential direction of the rotor assembly, and the second lamination is provided with a fourth protrusion on one side along the circumferential direction of the rotor assembly. The third protrusion and the fourth protrusion are located on both sides of the core body along the circumferential direction of the rotor assembly. A plurality of third protrusions form one of the second protrusions, and a plurality of fourth protrusions form another second protrusion.

[0019] In some embodiments of this application, the first lamination and the third protrusion are exactly the same as the second lamination and the fourth protrusion, respectively.

[0020] In some embodiments of this application, the core body is provided with the second protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes a plurality of laminations stacked along the axial direction of the rotor assembly. Each lamination is provided with a third protrusion and a fourth protrusion on both sides along the circumferential direction of the rotor assembly. The plurality of third protrusions form one of the second protrusions, and the plurality of fourth protrusions form another second protrusion.

[0021] According to some embodiments of this application, in a cross-section perpendicular to the axial direction of the rotor assembly, the permanent magnet is rectangular, and all the side edges of the permanent magnet extending along the axial direction of the rotor assembly are right angles.

[0022] According to some embodiments of this application, at least one end face of the permanent magnet along the axial direction of the rotor assembly has a chamfer between it and the sidewall of the permanent magnet.

[0023] In some embodiments of this application, in the circumferential direction of the rotor assembly, the thickness of the magnet is H, the chamfer is a rounded chamfer, the radius of the rounded chamfer is R1, and satisfies: 0.06≤R1 / H≤0.24; or, the chamfer is a straight-edge chamfer, the chamfer size of the straight edge is C1, and satisfies: 0.06≤C1 / H≤0.24.

[0024] According to some embodiments of this application, the relief groove is circular, elliptical, or polygonal in shape on a cross-section perpendicular to the axial direction of the rotor assembly.

[0025] According to some embodiments of this application, the core body is provided with a positioning hole and an injection hole that penetrate the core body along the axial direction of the rotor assembly, as well as rivet points for connecting multiple laminations of the core body.

[0026] The motor according to an embodiment of this application includes the rotor assembly described above.

[0027] According to the embodiments of this application, the motor, by setting the rotor assembly described above, has a protrusion on at least one side of the iron core body along the circumferential direction of the rotor assembly, such that the permanent magnet is located inside or outside the protrusion along the radial direction of the rotor assembly. A clearance groove facing the permanent magnet is provided at the connection between at least one protrusion and the iron core body, extending along the axial direction of the rotor assembly. Simultaneously, the corner opposite the permanent magnet to the clearance groove is a right angle, which can improve the demagnetization resistance of the permanent magnet at the corner opposite the clearance groove, reduce local demagnetization of the permanent magnet, and to a certain extent improve the motor's demagnetization resistance, thereby increasing the motor's demagnetization current. Furthermore, increasing the amount of permanent magnet at the corner opposite the clearance groove can improve the motor's output capacity and efficiency, and can reduce the magnetic bridge width at the protrusion, reducing magnetic leakage. Additionally, the right angle of the side edge of the permanent magnet opposite the clearance groove eliminates the need for the permanent magnet chamfering process, facilitating the processing and dimensional control of the permanent magnet.

[0028] The electrical equipment according to the embodiments of this application includes the motor described above.

[0029] According to the electrical equipment of the present application embodiment, by setting the above-mentioned motor, a protrusion is provided on at least one side of the iron core body along the circumferential direction of the rotor assembly, such that the permanent magnet is located inside or outside the protrusion along the radial direction of the rotor assembly, and a relief groove facing the permanent magnet is provided at the connection between at least one protrusion and the iron core body. The relief groove extends along the axial direction of the rotor assembly, and the corner opposite the permanent magnet and the relief groove is a right angle. This can improve the anti-demagnetization ability of the permanent magnet at the corner opposite the relief groove, reduce the local demagnetization of the permanent magnet, and improve the anti-demagnetization ability of the motor to a certain extent, thereby increasing the demagnetization current of the motor. In addition, the amount of permanent magnet at the corner opposite the relief groove can be increased, improving the output capacity and efficiency of the motor, and reducing the magnetic bridge width at the protrusion, thus reducing magnetic leakage. In addition, the side edge of the permanent magnet opposite the relief groove is a right angle, which can eliminate the chamfering process of the permanent magnet, making it easier to process and control the size of the permanent magnet.

[0030] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0031] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0032] Figure 1 is a schematic diagram of a motor according to an embodiment of this application;

[0033] Figure 2 is a top view of a rotor assembly according to an embodiment of this application;

[0034] Figure 3 is a cross-sectional view of a rotor assembly according to an embodiment of this application;

[0035] Figure 4 is a partial schematic diagram of the rotor assembly in Figure 3;

[0036] Figure 5 is an enlarged view of point A in Figure 4;

[0037] Figure 6 is an enlarged view of point B in Figure 4;

[0038] Figure 7 is a cross-sectional view of the permanent magnet of the rotor assembly according to an embodiment of the present application, perpendicular to the axis of the rotor assembly;

[0039] Figure 8 is a cross-sectional view of a rotor assembly according to another embodiment of this application;

[0040] Figure 9 is an enlarged view of point C in Figure 8;

[0041] Figure 10 is a cross-sectional view of a rotor assembly according to another embodiment of this application, which is in a different position from the cross-sectional view in Figure 8;

[0042] Figure 11 is an enlarged view of point D in Figure 10;

[0043] Figure 12 is a schematic diagram of the permanent magnet of the rotor assembly according to an embodiment of the present application, wherein the chamfer is a rounded corner;

[0044] Figure 13 is a schematic diagram of the permanent magnet of the rotor assembly according to an embodiment of the present application, wherein the chamfer is a straight edge chamfer;

[0045] Figure 14 is a comparison of the demagnetizing current of the motor according to an embodiment of this application and a conventional motor;

[0046] Figure 15 shows the back electromotive force of the motor according to an embodiment of this application and a conventional motor.

[0047] Reference numerals: 100, Motor; 10, Rotor assembly; 1, Rotor core; 11, Core unit; 111, Core body; 1111, First lamination; 1112, Second lamination; 112, Protrusion; 1121, First protrusion; 1122, Second protrusion; 1123, First tab; 1124, Second tab; 1125, Third tab; 1126, Fourth tab; 113, Relief groove; 1131, First relief groove; 1132, Second relief groove; 1133, First groove; 1134, Second groove; 114, Positioning hole; 115, Injection hole; 116, Riveting point; 2, Permanent magnet; 21, Chamfer; 20, Stator assembly. Detailed Implementation

[0048] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0049] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] The rotor assembly 10 according to an embodiment of this application is described below with reference to the accompanying drawings.

[0052] As shown in Figures 1-4, the rotor assembly 10 according to an embodiment of this application includes a rotor core 1 and a permanent magnet 2.

[0053] Specifically, the rotor core 1 includes multiple core units 11, each core unit 11 including a core body 111 and multiple permanent magnets 2. The multiple permanent magnets 2 and the multiple core bodies 111 are arranged alternately in the circumferential direction of the rotor assembly 10. It can be understood that, along the circumferential direction of the rotor assembly 10, a permanent magnet 2 is provided between every two adjacent core bodies 111, and a core body 111 is provided between every two adjacent permanent magnets 2.

[0054] As shown in Figures 3 and 4, the core body 111 has a protrusion 112 on at least one side of the two sides along the circumferential direction of the rotor assembly 10. The protrusion 112 can extend along the axial direction of the rotor assembly 10. The permanent magnet 2 is located inside or outside the protrusion 112 along the radial direction of the rotor assembly 10. At least one protrusion 112 and the core body 111 are provided with a relief groove 113 facing the permanent magnet 2. Correspondingly, the relief groove 113 extends along the axial direction of the rotor assembly 10. The corner between the permanent magnet 2 and the relief groove 113 is a right angle.

[0055] It is understood that the core body 111 has a protrusion 112 on one side of the rotor assembly 10 along the circumferential direction. The protrusion 112 can be located on the radially outer side of the permanent magnet 2 along the radial direction of the rotor assembly 10. Alternatively, the core body 111 has a protrusion 112 on one side of the rotor assembly 10 along the circumferential direction. The protrusion 112 can be located on the radially inner side of the permanent magnet 2 along the radial direction of the rotor assembly 10. Or, the core body 111 has protrusions 112 on both sides of the rotor assembly 10 along the circumferential direction. The two protrusions 112 are respectively located on the sides of the permanent magnet 2 along the circumferential direction of the rotor assembly 10. The rotor assembly 10 is provided with protrusions 112 on the radial outer side in the radial direction, or on both sides of the core body 111 along the circumferential direction of the rotor assembly 10. The two protrusions 112 are respectively located on the radial inner side of the permanent magnet 2 on both sides of the core body 111 along the circumferential direction of the rotor assembly 10 in the radial direction. Alternatively, the core body 111 is provided with protrusions 112 on both sides of the rotor assembly 10 in the circumferential direction. One of the two protrusions 112 can be located on the radial outer side of the permanent magnet 2 on the same side along the radial direction of the rotor assembly 10, and the other can be located on the radial inner side of the permanent magnet 2 on the same side along the radial direction of the rotor assembly 10.

[0056] One or more protrusions 112 may be provided on the same side of the core body 111 along the circumferential direction of the rotor assembly 10. When one protrusion 112 is provided on the same side of the core body 111 along the circumferential direction of the rotor assembly 10, the protrusion 112 is located inside or outside the permanent magnet 2 along the radial direction of the rotor assembly 10. When multiple protrusions 112 are provided on the same side of the core body 111 along the circumferential direction of the rotor assembly 10, for example, when there are two protrusions 112, the two protrusions 112 may be located inside and outside the permanent magnet 2 along the radial direction of the rotor assembly 10, respectively.

[0057] In addition, when the iron core body 111 is provided with a plurality of protrusions 112, at least one protrusion 112 is provided with a clearance groove 113 at the corner of the iron core body 111 facing the permanent magnet 2. It is possible that each protrusion 112 is provided with a clearance groove 113 at the corner of the iron core body 111 facing the permanent magnet 2, or that some of the protrusions 112 are provided with a clearance groove 113 at the corner of the iron core body 111 facing the permanent magnet 2.

[0058] In the examples shown in Figures 3 and 4, the core body 111 has two protrusions 112 on both sides of the rotor assembly 10 along the circumferential direction. The two protrusions 112 on the same side of the core body 111 along the circumferential direction of the rotor assembly 10 are located on the inner and outer sides of the permanent magnet 2 along the radial direction of the rotor assembly 10, respectively. Each protrusion 112 and the core body 111 are provided with a relief groove 113 facing the permanent magnet 2. The relief groove 113 extends along the axial direction of the rotor assembly 10. The four corners of the permanent magnet 2 opposite to the four relief grooves 113 are all right angles.

[0059] In this application, by providing a clearance groove 113 at the corner of the protrusion 112 and the iron core body 111 facing the permanent magnet 2, the corner where the edge of the permanent magnet 2 is located opposite the clearance groove 113 can be set as a right angle without chamfering. This can improve the demagnetization resistance of the permanent magnet 2 at the corner opposite the clearance groove 113, reduce the local demagnetization of the permanent magnet 2, and improve the demagnetization resistance of the motor 100 to a certain extent, thereby increasing the demagnetization current of the motor 100. In addition, the amount of permanent magnet 2 at the corner opposite the clearance groove 113 can be increased, improving the output capacity and efficiency of the motor 100, and reducing the magnetic bridge width at the protrusion 112, thus reducing magnetic leakage. Furthermore, since the side edge of the permanent magnet 2 opposite the clearance groove 113 is a right angle, the chamfering process of the permanent magnet 2 can be omitted, which facilitates the processing and dimensional control of the permanent magnet 2.

[0060] According to the rotor assembly 10 of this application embodiment, a protrusion 112 is provided on at least one side of the iron core body 111 along the circumferential direction of the rotor assembly 10, such that the permanent magnet 2 is located inside or outside the protrusion 112 along the radial direction of the rotor assembly 10. A clearance groove 113 is provided at the connection between at least one protrusion 112 and the iron core body 111, facing the permanent magnet 2. The clearance groove 113 extends along the axial direction of the rotor assembly 10, and the corners of the permanent magnet 2 and the clearance groove 113 are right angles. This improves the demagnetization resistance of the permanent magnet 2 at the corners opposite to the clearance groove 113, reduces local demagnetization of the permanent magnet 2, and to a certain extent enhances the demagnetization resistance of the motor 100, thereby increasing the demagnetization current of the motor 100. Furthermore, increasing the amount of permanent magnet 2 at the corners opposite to the clearance groove 113 can improve the output capacity and efficiency of the motor 100, and can reduce the magnetic bridge width at the protrusion 112, reducing magnetic leakage. In addition, the side edge of the permanent magnet 2 opposite to the relief groove 113 is a right angle, which can omit the chamfering process of the permanent magnet 2, making it easier to process and control the size of the permanent magnet 2.

[0061] In some embodiments of this application, as shown in Figures 5 and 6, the clearance groove 113 includes a first groove 1133 located on the iron core body 111 and a second groove 1134 located on the protrusion 112, wherein the first groove 1133 and the second groove 1134 are connected. It is understood that part of the clearance groove 113 is located on the iron core body 111 and part is located on the protrusion 112. The clearance groove 113 can make way for the permanent magnet 2 on both sides of the corner of the permanent magnet 2 opposite to the clearance groove 113, facilitating insertion between two iron core units 11 when the corner of the permanent magnet 2 opposite to the clearance groove 113 is a right angle, avoiding damage to the corner and preventing a reduction in the demagnetization resistance of the permanent magnet 2.

[0062] Furthermore, as shown in Figures 5 and 6, in the direction from the bottom of the first groove 1133 to the open opening, the sidewall of the end of the first groove 1133 opposite to the second groove 1134 is inclined in the direction opposite to the second groove 1134. Similarly, in the direction from the bottom of the second groove 1134 to the open opening, the sidewall of the end of the second groove 1134 opposite to the first groove 1133 is inclined in the direction opposite to the first groove 1133. This facilitates the processing and manufacturing of the clearance groove 113.

[0063] In some embodiments of this application, as shown in Figures 4 and 5, the protrusion 112 includes a first protrusion 1121, the clearance groove 113 includes a first clearance groove 1131, the core body 111 is provided with a first protrusion 1121 on at least one side of the two sides along the circumferential direction of the rotor assembly 10, the first protrusion 1121 is located at the outer end of the core body 111 along the radial direction of the rotor assembly 10, the permanent magnet 2 is located on the radial inner side of the first protrusion 1121, at least one first protrusion 1121 and the core body 111 are provided with a first clearance groove 1131 facing the permanent magnet 2, and the corner opposite the permanent magnet 2 and the first clearance groove 1131 is a right angle.

[0064] It is understood that the core body 111 has a first protrusion 1121 on one side of the rotor assembly 10 along the circumferential direction. The first protrusion 1121 is located at the outer end of the core body 111 along the radial direction of the rotor assembly 10, and the permanent magnet 2 is located radially inside the first protrusion 1121. The connection between the first protrusion 1121 and the core body 111 has a first clearance groove 1131 facing the permanent magnet 2. Alternatively, the core body 111 has a first protrusion 1121 on both sides of the rotor assembly 10 along the circumferential direction. The first protrusion 1121 is located at the outer end of the core body 111 along the radial direction of the rotor assembly 10, and the permanent magnet 2 is located on the radial inner side of the first protrusion 1121. The body 2 is located radially inside the two first protrusions 1121 respectively. One of the two first protrusions 1121 is provided with a first clearance groove 1131 facing the permanent magnet 2 on the same side at the connection between it and the iron core body 111; or the iron core body 111 is provided with first protrusions 1121 on both sides along the circumferential direction of the rotor assembly 10. The first protrusions 1121 are located at the outer end of the iron core body 111 along the radial direction of the rotor assembly 10. The permanent magnets 2 on both sides of the iron core body 111 along the circumferential direction of the rotor are located radially inside the two first protrusions 1121 respectively. The connection between the two first protrusions 1121 and the iron core body 111 is provided with a first clearance groove 1131 facing the permanent magnet 2 on the same side.

[0065] The first protrusion 1121 can limit the permanent magnet 2 in the radially outward direction, ensuring the reliability of the permanent magnet 2's fixation and preventing it from being thrown out during the rotation of the rotor assembly 10, thus improving the reliability of the motor 100's operation. The first clearance groove 1131 ensures that the corner between the permanent magnet 2 and the first clearance groove 1131 is a right angle, improving the demagnetization resistance of the permanent magnet 2 at the corner opposite to the first clearance groove 1131, reducing local demagnetization of the permanent magnet 2, and to a certain extent enhancing the demagnetization resistance of the motor 100, thereby increasing the demagnetization current of the motor 100. Furthermore, increasing the amount of permanent magnet 2 at the corner opposite to the first clearance groove 1131 can improve the output capacity and efficiency of the motor 100, and can reduce the magnetic bridge width at the first protrusion 1121, reducing magnetic leakage. In addition, the side edge of the permanent magnet 2 opposite to the first clearance groove 1131 is a right angle, which can omit the chamfering process of the permanent magnet 2, making it easier to process and control the size of the permanent magnet 2.

[0066] Furthermore, as shown in Figures 4 and 5, the minimum distance between the inner wall of the first clearance groove 1131 and the outer wall of the end of the core body 111 facing away from the axis of the rotor assembly 10 is h2, and satisfies: h2 ≥ 0.5 mm. This facilitates the manufacturing of the core unit 11, enables mass production of the core unit 11, and improves production efficiency. For example, in the example shown in Figures 4 and 5, h2 is the minimum distance between the second groove 1134 and the outer wall of the end of the core body 111 facing away from the axis of the rotor assembly 10.

[0067] In some embodiments of this application, as shown in Figures 4 and 5, the minimum distance between the inner wall of the first clearance groove 1131 and the outer wall of the end of the iron core body 111 facing away from the axis of the rotor assembly 10 is h2, and the distance between the inner wall of the portion of the first clearance groove 1131 located on the iron core body 111 and the side wall of the permanent magnet 2 near the iron core body 111 is h1, satisfying: 0.25≤h1 / h2≤0.65. It can be understood that h1 can be the distance between the inner wall of the first groove 1133 and the surface of the permanent magnet 2 facing the first groove 1133. h1 / h2 can be 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, or 0.6, etc. This allows for control of the demagnetization of the permanent magnet 2 and reduces magnetic leakage.

[0068] In some embodiments of this application, as shown in Figures 5 and 7, the radial length of the permanent magnet 2 is L, and the maximum radial dimension of the first clearance groove 1131 is W2, satisfying: 0.1 ≤ W2 / L ≤ 0.16. W2 / L can be 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, or 0.16, etc. This allows for control of the demagnetization of the permanent magnet 2, reducing magnetic leakage, and facilitating the manufacturing of the core unit 11, enabling mass production of the core unit 11, and improving production efficiency.

[0069] In some embodiments of this application, the core body 111 is provided with first protrusions 1121 on both sides of the rotor assembly 10 in the circumferential direction. The core body 111 includes first laminations 1111 and second laminations 1112 stacked alternately in the axial direction of the rotor assembly 10. The first laminations 1111 are provided with first protrusions 1123 on one side of the rotor assembly 10 in the circumferential direction, and the second laminations 1112 are provided with second protrusions 1124 on one side of the rotor assembly 10 in the circumferential direction. The first protrusions 1123 and the second protrusions 1124 are located on both sides of the core body 111 in the circumferential direction of the rotor assembly 10. A plurality of first protrusions 1123 form one first protrusion 1121, and a plurality of second protrusions 1124 form another first protrusion 1121.

[0070] It is understood that any two adjacent first protrusions 1123 are spaced apart, with the spacing being the distance of one second lamination 1112, and any two adjacent second protrusions 1124 are spaced apart, with the spacing being the distance of one first lamination 1111. Furthermore, the first protrusion 1121 includes either first protrusions 1123 spaced apart along the axial direction of the rotor assembly 10 or second protrusions 1124 spaced apart along the axial direction of the rotor assembly 10. This reduces magnetic leakage from the permanent magnet 2.

[0071] When a first clearance groove 1131 is present between the first protrusion 1121 formed by multiple first protrusions 1123 and the iron core body 111, the first clearance groove 1131 penetrates through the multiple first protrusions 1123, multiple first laminations 1111, and multiple second laminations 1112. Specifically, the first groove 1133 penetrates through the multiple first laminations 1111 and multiple second laminations 1112, multiple second grooves 1134 penetrate through the multiple first protrusions 1123, and the side of the second lamination 1112 closest to the first protrusion 1123 has only the first groove 1133. When a first clearance groove 1131 is present between the first protrusion 1121 formed by multiple second protrusions 1124 and the iron core body 111, the first clearance groove 1131 penetrates through the multiple second protrusions 1124, multiple first laminations 1111, and multiple second laminations 1112. Specifically, the first groove 1133 penetrates multiple first stamps 1111 and multiple second stamps 1112, and multiple second grooves 1134 penetrate multiple second protrusions 1124. The side of the first stamp 1111 closest to the second protrusion 1124 has only the first groove 1133.

[0072] In some embodiments of this application, the first punch 1111 and the first protrusion 1123 are integral parts, and the second punch 1112 and the second protrusion 1124 are integral parts.

[0073] In some embodiments of this application, the first lamination 1111 and the first protrusion 1123 are identical to the second lamination 1112 and the second protrusion 1124, respectively. It is understood that the overall structure formed by the first lamination 1111 and the first protrusion 1123 is identical to the overall structure formed by the second lamination 1112 and the second protrusion 1124. When the overall structure formed by the first lamination 1111 and the first protrusion 1123 is alternately stacked with the overall structure formed by the second lamination 1112 and the second protrusion 1124, it is only necessary to rotate the second lamination 1112 180 degrees relative to the first lamination 1111 about the radial rotation axis. At this time, the first protrusion 1123 and the second protrusion 1124 are located on opposite sides of the core body 111 along the circumferential direction of the rotor assembly 10.

[0074] This facilitates the processing of the overall structure of the first punch 1111 and the first protrusion 1123, as well as the processing of the overall structure of the second punch 1112 and the second protrusion 1124, thereby improving production efficiency and reducing costs.

[0075] In some embodiments of this application, the core body 111 is provided with first protrusions 1121 on both sides of the rotor assembly 10 in the circumferential direction. The core body 111 includes a plurality of laminations stacked along the axial direction of the rotor assembly 10. Each lamination is provided with a first protrusion 1123 and a second protrusion 1124 on both sides of the rotor assembly 10 in the circumferential direction. The plurality of first protrusions 1123 form one of the first protrusions 1121, and the plurality of second protrusions 1124 form another first protrusion 1121.

[0076] It is understood that multiple first protrusions 1123 are stacked to form a first protrusion 1121, and two adjacent first protrusions 1123 are attached or abutted to each other. Multiple second protrusions 1124 are stacked to form a second protrusion 1122, and two adjacent second protrusions 1124 are attached or abutted to each other.

[0077] When a first clearance groove 1131 is present between the first protrusion 1121 formed by multiple first protrusions 1123 and the iron core body 111, the first clearance groove 1131 penetrates through the multiple first protrusions 1123 and the multiple laminations. Specifically, the first groove 1133 penetrates through the multiple first laminations, and multiple second grooves 1134 penetrate through the multiple first protrusions 1123. When a first clearance groove 1131 is present between the first protrusion 1121 formed by multiple second protrusions 1124 and the iron core body 111, the first clearance groove 1131 penetrates through the multiple second protrusions 1124 and the multiple first laminations. Specifically, the first groove 1133 penetrates through the multiple laminations, and multiple second grooves 1134 penetrate through the multiple second protrusions 1124.

[0078] In some embodiments of this application, as shown in Figures 4 and 6, the protrusion 112 includes a second protrusion 1122, the clearance groove 113 includes a second clearance groove 1132, the core body 111 is provided with a second protrusion 1122 on at least one side of the two sides along the circumferential direction of the rotor assembly 10, the second protrusion 1122 is located at the inner end of the core body 111 along the radial direction of the rotor assembly 10, the permanent magnet 2 is located on the radial outer side of the second protrusion 1122, at least one second protrusion 1122 and the core body 111 are provided with a second clearance groove 1132 facing the permanent magnet 2, and the corner opposite the permanent magnet 2 and the second clearance groove 1132 is a right angle.

[0079] It is understood that the core body 111 has a second protrusion 1122 on one side of the rotor assembly 10 along the circumferential direction. The second protrusion 1122 is located at the inner end of the core body 111 along the radial direction of the rotor assembly 10, and the permanent magnet 2 is located on the radial outer side of the second protrusion 1122. The connection between the second protrusion 1122 and the core body 111 has a second clearance groove 1132 facing the permanent magnet 2; or the core body 111 has a second protrusion 1122 on both sides of the rotor assembly 10 along the circumferential direction. The second protrusion 1122 is located at the inner end of the core body 111 along the radial direction of the rotor assembly 10, and the permanent magnet 2 is located on the radial outer side of the core body 111 along the rotor circumferential direction. The body 2 is located radially outside the two second protrusions 1122 respectively. The connection between one of the two second protrusions 1122 and the iron core body 111 is provided with a second clearance groove 1132 facing the permanent magnet 2 on the same side; or the iron core body 111 is provided with second protrusions 1122 on both sides along the circumferential direction of the rotor assembly 10. The second protrusions 1122 are located at the inner end of the iron core body 111 along the radial direction of the rotor assembly 10. The permanent magnets 2 on both sides of the iron core body 111 along the circumferential direction of the rotor are located radially outside the two second protrusions 1122 respectively. The connection between the two second protrusions 1122 and the iron core body 111 is provided with a second clearance groove 1132 facing the permanent magnet 2 on the same side.

[0080] The second protrusion 1122 can limit the permanent magnet 2 in the radial direction, ensuring the reliability of the permanent magnet 2's fixation and improving the operational reliability of the motor 100. The second clearance groove 1132 ensures that the corner between the permanent magnet 2 and the second clearance groove 1132 is a right angle, improving the demagnetization resistance of the permanent magnet 2 at the corner opposite to the second clearance groove 1132, reducing localized demagnetization of the permanent magnet 2, and to a certain extent enhancing the demagnetization resistance of the motor 100, thereby increasing the demagnetization current of the motor 100. Furthermore, increasing the amount of permanent magnet 2 at the corner opposite to the second clearance groove 1132 can improve the output capacity and efficiency of the motor 100, and can reduce the magnetic bridge width at the second protrusion 1122, reducing magnetic leakage. Additionally, the right angle of the side edge of the permanent magnet 2 opposite to the second clearance groove 1132 eliminates the need for the chamfering process of the permanent magnet 2, facilitating its processing and dimensional control.

[0081] In some embodiments of this application, as shown in Figures 4 and 6, the minimum width of the core body 111 at the outlet of the second clearance groove 1132 is w, and satisfies: w ≥ 0.5 mm. This facilitates the manufacturing of the core unit 11, enables mass production of the core unit 11, and improves production efficiency.

[0082] In some embodiments of this application, as shown in Figures 8-11, the core body 111 has second protrusions 1122 on both sides of the rotor assembly 10 in the circumferential direction. The core body 111 includes first laminations 1111 and second laminations 1112 stacked alternately in the axial direction of the rotor assembly 10. The first lamination 1111 has a third protrusion 1125 on one side of the rotor assembly 10 in the circumferential direction, and the second lamination 1112 has a fourth protrusion 1126 on one side of the rotor assembly 10 in the circumferential direction. The third protrusions 1125 and the fourth protrusions 1126 are located on both sides of the core body 111 in the circumferential direction of the rotor assembly 10. Multiple third protrusions 1125 form one of the second protrusions 1122, and multiple fourth protrusions 1126 form another second protrusion 1122.

[0083] It is understood that any two adjacent third protrusions 1125 are spaced apart, with the spacing being the distance of one second lamination 1112, and any two adjacent fourth protrusions 1126 are spaced apart, with the spacing being the distance of one first lamination 1111. Furthermore, the second protrusion 1122 includes either third protrusions 1125 spaced apart along the axial direction of the rotor assembly 10 or fourth protrusions 1126 spaced apart along the axial direction of the rotor assembly 10. This reduces magnetic leakage from the permanent magnet 2.

[0084] When a second clearance groove 1132 is provided between the second protrusion 1122 formed by multiple third protrusions 1125 and the core body 111, the second clearance groove 1132 penetrates through the multiple third protrusions 1125, the multiple first laminations 1111, and the multiple second laminations 1112. Specifically, the first groove 1133 penetrates through the multiple first laminations 1111 and the multiple second laminations 1112, the multiple second grooves 1134 penetrate through the multiple third protrusions 1125, and the side of the second lamination 1112 closest to the third protrusion 1125 has only the first groove 1133. When a second clearance groove 1132 is provided between the second protrusion 1122 formed by multiple fourth protrusions 1126 and the core body 111, the second clearance groove 1132 penetrates through the multiple fourth protrusions 1126, the multiple first laminations 1111, and the multiple second laminations 1112. Specifically, the first groove 1133 penetrates multiple first stamps 1111 and multiple second stamps 1112, and multiple second grooves 1134 penetrate multiple fourth protrusions 1126. The side of the first stamp 1111 closest to the fourth protrusion 1126 has only the first groove 1133.

[0085] In some embodiments of this application, the first punch 1111 and the third protrusion 1125 are integral parts, and the second punch 1112 and the fourth protrusion 1126 are integral parts.

[0086] In some embodiments of this application, the first lamination 1111 and the third protrusion 1125 are identical to the second lamination 1112 and the fourth protrusion 1126, respectively. It is understood that the overall structure formed by the first lamination 1111 and the third protrusion 1125 is identical to the overall structure formed by the second lamination 1112 and the fourth protrusion 1126. When the overall structure formed by the first lamination 1111 and the third protrusion 1125 is alternately stacked with the overall structure formed by the second lamination 1112 and the fourth protrusion 1126, it is only necessary to rotate the second lamination 1112 180 degrees relative to the first lamination 1111 about the radial rotation axis. At this time, the third protrusion 1125 and the fourth protrusion 1126 are located on opposite sides of the core body 111 along the circumferential direction of the rotor assembly 10.

[0087] This facilitates the machining of the overall structure of the first lamination 1111 and the third protrusion 1125, as well as the machining of the overall structure of the second lamination 1112 and the fourth protrusion 1126, thereby improving production efficiency and reducing costs.

[0088] In some embodiments of this application, the core body 111 is provided with second protrusions 1122 on both sides of the rotor assembly 10 in the circumferential direction. The core body 111 includes a plurality of laminations stacked along the axial direction of the rotor assembly 10. Each lamination is provided with a third protrusion 1125 and a fourth protrusion 1126 on both sides of the rotor assembly 10 in the circumferential direction. The plurality of third protrusions 1125 form one of the second protrusions 1122, and the plurality of fourth protrusions 1126 form another second protrusion 1122.

[0089] It is understood that multiple third protrusions 1125 are stacked to form a second protrusion 1122, and two adjacent third protrusions 1125 are attached or abutted to each other. Multiple fourth protrusions 1126 are stacked to form a second protrusion 1122, and two adjacent fourth protrusions 1126 are attached or abutted to each other.

[0090] When a second clearance groove 1132 is present between the second protrusion 1122 formed by multiple third protrusions 1125 and the core body 111, the second clearance groove 1132 penetrates through the multiple third protrusions 1125 and the multiple laminations. Specifically, a first groove 1133 penetrates through the multiple laminations, and multiple second grooves 1134 penetrate through the multiple third protrusions 1125. When a second clearance groove 1132 is present between the second protrusion 1122 formed by multiple fourth protrusions 1126 and the core body 111, the second clearance groove 1132 penetrates through the multiple fourth protrusions 1126 and the multiple laminations. Specifically, a first groove 1133 penetrates through the multiple laminations, and multiple second grooves 1134 penetrate through the multiple fourth protrusions 1126.

[0091] In some embodiments of this application, as shown in Figures 3 and 7, the core body 111 has two protrusions 112, namely a first protrusion 1121 and a second protrusion 1122, on both sides of the rotor assembly 10 along the circumferential direction. The first protrusion 1121 and the second protrusion 1122 on the same side of the core body 111 along the circumferential direction of the rotor assembly 10 are respectively located on the outer and inner sides of the permanent magnet 2 along the radial direction of the rotor assembly 10. Each first protrusion 1121 has a first clearance groove 1131 facing the permanent magnet 2 at the connection between it and the core body 111, and each second protrusion 1122 has a second clearance groove 1132 facing the permanent magnet 2 at the connection between it and the core body 111. In the cross-section perpendicular to the axial direction of the rotor assembly 10, the permanent magnet 2 is rectangular, and the side edges of the permanent magnet 2 extending along the axial direction of the rotor assembly 10 are all right angles. As shown in Figures 14 and 15, this application improves both the demagnetizing current and the line back electromotive force compared to the conventional scheme.

[0092] This improves the demagnetization resistance of the permanent magnet 2, reduces localized demagnetization, and to a certain extent enhances the demagnetization resistance of the motor 100, thereby increasing the demagnetization current of the motor 100. Furthermore, increasing the amount of permanent magnet 2 improves the output capacity and efficiency of the motor 100, and reduces the magnetic bridge width at the first protrusion 1121 and the second protrusion 1122, reducing magnetic leakage. Additionally, the right-angle design eliminates the need for chamfering the permanent magnet 2, facilitating its processing and dimensional control.

[0093] In some embodiments of this application, as shown in Figures 12 and 13, at least one end face of the permanent magnet 2 along the axial direction of the rotor assembly 10 has a chamfer 21 between it and the sidewall of the permanent magnet 2. It is understood that the chamfer 21 may be present between only one end face of the permanent magnet 2 along the axial direction of the rotor assembly 10 and the sidewall of the permanent magnet 2, or both end faces of the permanent magnet 2 along the axial direction of the rotor assembly 10 and the sidewall of the permanent magnet 2 may have a chamfer 21. Specifically, when the chamfer 21 is present between the end face of the permanent magnet 2 along the axial direction of the rotor assembly 10 and the sidewall of the permanent magnet 2, it may be between the end face of the permanent magnet 2 along the axial direction of the rotor assembly 10 and a portion of the sidewall of the permanent magnet 2, or it may be between the end face of the permanent magnet 2 along the axial direction of the rotor assembly 10 and all the sidewalls of the permanent magnet 2.

[0094] During the assembly of the rotor assembly 10, multiple iron core units 11 are first arranged, and then permanent magnets 2 are inserted between two adjacent iron core units 11. At least one end face of the permanent magnet 2 along the axial direction of the rotor assembly 10 has a chamfer 21 between it and the side wall of the permanent magnet 2. The chamfer 21 can play a guiding role during the insertion of the permanent magnet 2, making it easier to insert the permanent magnet 2 between the two iron core units 11.

[0095] In some embodiments of this application, the thickness of the magnet in the circumferential direction of the rotor assembly 10 is H. As shown in Figure 12, the chamfer 21 is a rounded chamfer with a radius of R1, satisfying: 0.06 ≤ R1 / H ≤ 0.24. As shown in Figure 13, the chamfer 21 is a straight-edge chamfer with a dimension of C1, satisfying: 0.06 ≤ C1 / H ≤ 0.24. This facilitates the assembly of the permanent magnet 2 between the two core units 11 and ensures the demagnetization resistance of the permanent magnet 2.

[0096] For example, when chamfer 21 is a rounded chamfer, R1 / H can be 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, or 0.23. When chamfer 21 is a straight-edge chamfer, C1 / H can be 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, or 0.23.

[0097] In some embodiments of this application, the relief groove 113 is circular, elliptical, or polygonal in shape on a cross-section perpendicular to the axial direction of the rotor assembly 10. This increases the structural diversity of the relief groove 113 and can meet different needs. Specifically, when the relief groove 113 is polygonal, it can be rectangular, trapezoidal, or similar shapes.

[0098] In some embodiments of this application, as shown in Figures 3, 4 and 10, the core body 111 is provided with a positioning hole 114 and an injection hole 115 that penetrate the core body 111 along the axial direction of the rotor assembly 10, as well as rivet points 116 for connecting multiple laminations of the core body 111.

[0099] The core body 111 comprises multiple stacked laminations, and rivet points 116 connect the multiple laminations. Each lamination has a protrusion protruding from one side of the lamination thickness direction by a stamping device, and a recess corresponding to the protrusion on the other side of the lamination thickness direction. The protrusion of one of two adjacent laminations is riveted into the recess of the other. In the example shown in Figure 4, there are multiple rivet points 116, such as three. One of the three rivet points 116 is located at the inner end of the core body 111 along the radial direction of the rotor, and two rivet points 116 are located at the outer end of the core body 111 along the radial direction of the rotor assembly 10 and are spaced apart along the circumferential direction of the rotor assembly 10. Each rivet point 116 is formed as a rectangle, that is, each protrusion and each recess is formed as a rectangle.

[0100] Positioning holes 114 and injection holes 115 are used to connect multiple iron core units 11. Positioning holes 114 are non-circular holes. When connecting multiple iron core units 11, the multiple iron core units 11 are first positioned through positioning holes 114. Positioning holes 114 can cooperate with positioning posts on external equipment. After inserting permanent magnets 2 between each pair of adjacent iron core units 11, molding material is injected into each injection hole 115. Multiple iron core units 11 are connected together to form a rotor assembly 10 through the injection material.

[0101] The motor 100 according to an embodiment of this application is described below.

[0102] As shown in Figure 1, the motor 100 according to the embodiment of this application includes the rotor assembly 10 described above. The motor 100 of this application also includes a stator assembly 20. The rotor assembly 10 is rotatably disposed within the stator assembly 20. The motor 100 is an internal rotor motor 100.

[0103] According to the embodiment of this application, the motor 100, by providing the rotor assembly 10 described above, has a protrusion 112 on at least one side of the iron core body 111 along the circumferential direction of the rotor assembly 10, such that the permanent magnet 2 is located inside or outside the protrusion 112 along the radial direction of the rotor assembly 10, and a relief groove 113 facing the permanent magnet 2 is provided at the connection between at least one protrusion 112 and the iron core body 111. The relief groove 113 extends along the axial direction of the rotor assembly 10, and the corner between the permanent magnet 2 and the relief groove 113 is a right angle, which can improve the demagnetization resistance of the permanent magnet 2 at the corner opposite to the relief groove 113, reduce the local demagnetization of the permanent magnet 2, and improve the demagnetization resistance of the motor 100 to a certain extent, thereby increasing the demagnetization current of the motor 100. In addition, the amount of permanent magnet 2 can be increased at the corner opposite to the relief groove 113, which can improve the output capacity and efficiency of the motor 100, and reduce the width of the magnetic bridge at the protrusion 112, thus reducing magnetic leakage. Furthermore, since the side edge of the permanent magnet 2 opposite to the relief groove 113 is right-angled, the chamfering process of the permanent magnet 2 can be omitted, which facilitates the processing and dimensional control of the permanent magnet 2.

[0104] The following describes an electrical device according to an embodiment of this application.

[0105] The electrical device according to an embodiment of this application includes the motor 100 described above. The electrical device can be an air conditioner, and the motor 100 can be used to drive the fan wheel of the air conditioner to rotate.

[0106] According to the electrical equipment of the present application embodiment, by setting the motor 100 described above, a protrusion 112 is provided on at least one side of the iron core body 111 along the circumferential direction of the rotor assembly 10, such that the permanent magnet 2 is located inside or outside the protrusion 112 along the radial direction of the rotor assembly 10, and a relief groove 113 facing the permanent magnet 2 is provided at the connection between at least one protrusion 112 and the iron core body 111. The relief groove 113 extends along the axial direction of the rotor assembly 10, and the corner opposite the permanent magnet 2 and the relief groove 113 is a right angle, which can improve the anti-demagnetization ability of the permanent magnet 2 at the corner opposite the relief groove 113, reduce the local demagnetization of the permanent magnet 2, and improve the anti-demagnetization ability of the motor 100 to a certain extent, thereby increasing the demagnetization current of the motor 100. In addition, the amount of permanent magnet 2 can be increased at the corner opposite to the relief groove 113, which can improve the output capacity and efficiency of the motor 100, and reduce the width of the magnetic bridge at the protrusion 112, thus reducing magnetic leakage. Furthermore, since the side edge of the permanent magnet 2 opposite to the relief groove 113 is right-angled, the chamfering process of the permanent magnet 2 can be omitted, which facilitates the processing and dimensional control of the permanent magnet 2.

[0107] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0108] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor assembly, wherein, include: A rotor core, wherein the rotor core comprises multiple core units, and each core unit comprises a core body; The rotor assembly contains multiple permanent magnets, and these permanent magnets and multiple iron core bodies are arranged alternately in the circumferential direction. The core body has a protrusion on at least one side of the two sides along the circumferential direction of the rotor assembly. The permanent magnet is located inside or outside the protrusion along the radial direction of the rotor assembly. At least one of the protrusions and the core body has a relief groove facing the permanent magnet at the connection point. The relief groove extends along the axial direction of the rotor assembly. The corner between the permanent magnet and the relief groove is a right angle.

2. The rotor assembly according to claim 1, wherein, The clearance groove includes a first groove on the iron core body and a second groove on the protrusion, and the first groove and the second groove are connected.

3. The rotor assembly according to claim 1 or 2, wherein, The protrusion includes a first protrusion, the clearance groove includes a first clearance groove, the first protrusion is provided on at least one side of the iron core body along the circumferential direction of the rotor assembly, the first protrusion is located at the outer end of the iron core body along the radial direction of the rotor assembly, the permanent magnet is located on the radial inner side of the first protrusion, at least one of the first protrusion and the iron core body is provided with the first clearance groove facing the permanent magnet, and the corner opposite the permanent magnet and the first clearance groove is a right angle.

4. The rotor assembly according to claim 3, wherein, The minimum distance between the inner wall of the first clearance groove and the outer wall of the iron core body at the end opposite to the rotor assembly axis is h2, and satisfies: h2≥0.5mm; And / or, the minimum distance between the inner wall of the first clearance groove and the outer wall of the end of the iron core body opposite to the rotor assembly axis is h2, and the distance between the inner wall of the portion of the first clearance groove on the iron core body and the side wall of the permanent magnet near the iron core body is h1, and satisfies: 0.25≤h1 / h2≤0.65; And / or, the radial length of the permanent magnet is L, the maximum radial dimension of the first clearance groove is W2, and satisfies: 0.1≤W2 / L≤0.

16.

5. The rotor assembly according to claim 3 or 4, wherein, The core body has the first protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes first laminations and second laminations stacked alternately along the axial direction of the rotor assembly. The first lamination has a first protrusion on one side along the circumferential direction of the rotor assembly, and the second lamination has a second protrusion on one side along the circumferential direction of the rotor assembly. The first protrusion and the second protrusion are located on both sides of the core body along the circumferential direction of the rotor assembly. Multiple first protrusions form one of the first protrusions, and multiple second protrusions form another first protrusion.

6. The rotor assembly according to claim 5, wherein, The first lamination and the first protrusion are exactly the same as the second lamination and the second protrusion, respectively.

7. The rotor assembly according to claim 3 or 4, wherein, The core body is provided with the first protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes a plurality of laminations stacked along the axial direction of the rotor assembly. Each lamination is provided with a first protrusion and a second protrusion on both sides along the circumferential direction of the rotor assembly. The plurality of first protrusions form one of the first protrusions, and the plurality of second protrusions form another first protrusion.

8. The rotor assembly according to any one of claims 1-7, wherein, The protrusion includes a second protrusion, the clearance groove includes a second clearance groove, the second protrusion is provided on at least one side of the iron core body along the circumferential direction of the rotor assembly, the second protrusion is located at the inner end of the iron core body along the radial direction of the rotor assembly, the permanent magnet is located on the radial outer side of the second protrusion, at least one connection between the second protrusion and the iron core body is provided with a second clearance groove facing the permanent magnet, and the corner opposite the permanent magnet and the second clearance groove is a right angle.

9. The rotor assembly according to claim 8, wherein, The minimum width of the iron core body at the second clearance groove is w, and it satisfies: w≥0.5mm.

10. The rotor assembly according to claim 8 or 9, wherein, The core body has a second protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes a first lamination and a second lamination that are alternately stacked along the axial direction of the rotor assembly. The first lamination has a third protrusion on one side along the circumferential direction of the rotor assembly, and the second lamination has a fourth protrusion on one side along the circumferential direction of the rotor assembly. The third protrusion and the fourth protrusion are located on both sides of the core body along the circumferential direction of the rotor assembly. A plurality of third protrusions form one of the second protrusions, and a plurality of fourth protrusions form another second protrusion.

11. The rotor assembly of claim 10, wherein, The first lamination and the third protrusion are exactly the same as the second lamination and the fourth protrusion, respectively.

12. The rotor assembly according to claim 8 or 9, wherein, The core body is provided with the second protrusion on both sides along the circumferential direction of the rotor assembly. The core body includes a plurality of laminations stacked along the axial direction of the rotor assembly. Each lamination is provided with a third protrusion and a fourth protrusion on both sides along the circumferential direction of the rotor assembly. The plurality of third protrusions form one of the second protrusions, and the plurality of fourth protrusions form another second protrusion.

13. The rotor assembly according to any one of claims 1-12, wherein, In a cross-section perpendicular to the axial direction of the rotor assembly, the permanent magnet is rectangular, and all the side edges of the permanent magnet extending along the axial direction of the rotor assembly are right angles.

14. The rotor assembly according to any one of claims 1-13, wherein, At least one end face of the permanent magnet along the axial direction of the rotor assembly has a chamfer between it and the sidewall of the permanent magnet.

15. The rotor assembly of claim 14, wherein, In the circumferential direction of the rotor assembly, the thickness of the magnet is H. The chamfer is a rounded chamfer with a radius of R1, satisfying: 0.06≤R1 / H≤0.24; Alternatively, the chamfer is a straight-edge chamfer, and the chamfer size of the straight edge is C1, satisfying: 0.06≤C1 / H≤0.

24.

16. The rotor assembly according to any one of claims 1-15, wherein, In a cross-section perpendicular to the axial direction of the rotor assembly, the relief groove is circular, elliptical, or polygonal in shape.

17. The rotor assembly according to any one of claims 1-16, wherein, The core body is provided with positioning holes and injection holes that penetrate the core body along the axial direction of the rotor assembly, as well as rivet points for connecting multiple laminations of the core body.

18. An electric motor, wherein, Includes the rotor assembly according to any one of claims 1-17.

19. An electrical device comprising the motor according to claim 18.

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