Rotor assembly and motor

Abstract

The utility model relates to the technical field of motors, in particular to a rotor assembly and a motor. The rotor assembly comprises a rotor iron core and a permanent magnet; a plurality of mounting grooves are formed in the end surface of the rotor iron core, and are arranged at intervals along the circumferential direction of the rotor iron core; the mounting groove comprises a first groove part, the first groove part is rectangular, and the length direction of the first groove part is perpendicular to the radial direction of the rotor iron core; the permanent magnet is accommodated in the first groove part; wherein the length of the first groove part is L1, and the width of the first groove part is W1, 5.74 lt; l1 / W1lt; and 6.05). According to the rotor assembly and the motor, the permanent magnets are accommodated in the first groove parts, so that the strength of the rotor assembly can be improved, and the problem of rotor explosion of the motor is solved; by limiting the length-width ratio range of the first groove part, the motor efficiency and mechanical characteristics of the rotor assembly can be maintained in a proper range, and meanwhile the structural strength requirement of the rotor assembly is met.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a rotor assembly and a motor. Background Art

[0002] The motor is a crucial component of a remote-controlled car's powertrain, directly determining its performance. Existing motors typically utilize surface-mounted magnets on the rotor core, with the magnets mounted on the rotor core. These motors are prone to rotor explosion when subjected to high temperatures and high speeds, significantly shortening their service life. Utility Model Content

[0003] The embodiments of the present application aim to provide a rotor assembly and a motor, so as to at least improve the problem of motor rotor explosion.

[0004] In order to solve the above technical problems, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides a rotor assembly, comprising a rotor core and a permanent magnet; a plurality of mounting grooves are provided on an end surface of the rotor core, and the plurality of mounting grooves are arranged at intervals along the circumference of the rotor core; the mounting grooves include a first groove portion, the first groove portion is rectangular, and the length direction of the first groove portion is perpendicular to the radial direction of the rotor core; the permanent magnet is accommodated in the first groove portion; wherein the length of the first groove portion is L1, the width of the first groove portion is W1, and 5.74 <L1 / W1<6.05。

[0006] In some embodiments, the mounting slot also includes a second slot portion, which is connected to the first slot portion, and the second slot portion is arranged on the side of the first slot portion facing the outer edge of the rotor core. Along the length direction of the first slot portion, the two second slot portions are respectively flush with the two ends of the first slot portion; the rotor assembly also includes an adhesive, and the adhesive is filled in the second slot portion; wherein, the adhesive is a non-ferromagnetic material.

[0007] In some embodiments, the distance between the two second groove portions is L2, 0.723 <L2 / L1<0.824。

[0008] In some embodiments, the outer edge of the rotor core corresponding to the portion between any two adjacent first groove portions is recessed inward to form a magnetic isolation bridge, and the inner surface of the magnetic isolation bridge includes a first surface and a second surface, and the first surface and the second surface are both parallel to the axis of the rotor core; wherein the angle between the first surface and the second surface is α, 80 degrees < α < 90 degrees.

[0009] In a second aspect, an embodiment of the present application provides a motor, comprising a stator core and a rotor assembly as described above; the stator core comprises an annular stator yoke and a plurality of stator teeth, the plurality of stator teeth being arranged on the inner circumferential surface of the stator yoke, the plurality of stator teeth being arranged at intervals along the circumference of the stator yoke, a stator tooth slot being formed between two adjacent stator teeth, and the plurality of stator teeth defining a mounting cavity coaxial with the stator yoke; the rotor assembly being rotatably accommodated in the mounting cavity.

[0010] In some embodiments, the outer diameter of the stator yoke is D1, and the inner diameter of the mounting cavity is D2, 52.3 mm. <D1<53.6mm,0.564<D2 / D1<0.592。

[0011] In some embodiments, the inner diameter of the stator yoke is D3, 0.821 <D3 / D1<0.863。

[0012] In some embodiments, the tooth width of the stator teeth is W2, 2.5 mm <W2<2.9mm。

[0013] In some embodiments, the end of the stator tooth portion facing away from the stator yoke portion includes a tooth shoe, and the side of the tooth shoe facing away from the stator yoke portion is provided with an auxiliary slot, and the auxiliary slot extends along the axial direction of the stator core.

[0014] In some embodiments, along the circumference of the stator yoke, the auxiliary slot is located in the middle of the tooth shoe.

[0015] In some embodiments, the width of the auxiliary groove is W3, the depth of the auxiliary groove is H1, 1.90

[0016] The rotor assembly and motor of the embodiment of the present application can improve the strength of the rotor assembly and improve the problem of motor rotor explosion by accommodating the permanent magnet in the first slot portion; by limiting the aspect ratio range of the first slot portion, the motor efficiency and mechanical characteristics of the rotor assembly can be maintained within a suitable range while meeting the structural strength requirements of the rotor assembly.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] ​One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0019] Figure 1 is a cross-sectional view of a rotor assembly according to an embodiment of the present application;

[0020] Figure 2 is a schematic structural diagram of a motor according to an embodiment of the present application;

[0021] Figure 3 yes Figure 2 Cross-sectional view of the motor;

[0022] Figure 4 is a cross-sectional view of a stator core according to an embodiment of the present application;

[0023] Figure 5 yes Figure 4 A partial enlarged view of the stator core;

[0024] Figure 6 A comparison chart of the cogging torque of the motor according to the embodiment of the present application and the motor of the related art;

[0025] Figure 7 1 is a torque comparison diagram of the motor of the embodiment of the present application and the motor of the related art;

[0026] Figure 8 This is a temperature comparison diagram of the motor according to the embodiment of the present application and the motor according to the related art.

[0027] The accompanying drawings in the specific implementation manner are as follows:

[0028] 100. Motor;

[0029] 1. Rotor assembly; 11. Rotor core; 111. Mounting slot; 1111. First slot portion; 1112. Second slot portion; 1113. Arc chamfer; 1114. Glue slot; 112. Magnetic isolation bridge; 1121. First surface; 1122. Second surface; 12. Permanent magnet;

[0030] 2. Stator core; 21. Stator yoke; 22. Stator teeth; 221. Tooth shoe; 2211. Auxiliary slot; 23. Stator tooth slot; 24. Mounting cavity;

[0031] 3. Casing; 4. Front cover; 5. Rear cover; 6. Bearing; 7. Rotating shaft; 8. Rotor end plate. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0034] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0035] In the description of the embodiments of this application, the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In the description of the embodiments of this application, the meaning of "plurality" is two or more, unless otherwise specifically defined.

[0036] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.

[0037] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0038] First, see Figure 1 , an embodiment of the present application provides a rotor assembly 1, which includes a rotor core 11 and a permanent magnet 12. The rotor core 11 is a rotating body, for example, in a cylindrical shape. The permanent magnet 12 is installed on the rotor core 11. The permanent magnet 12 is generally in a long strip shape, and the number of the permanent magnets 12 is multiple.

[0039] In some embodiments, the permanent magnet 121 is a magnetic steel. Magnetic steel generally refers to an aluminum-nickel-cobalt alloy (AlNiCo, which is the abbreviation of aluminum-nickel-cobalt). Magnetic steel is a super-hard permanent magnet alloy made of several hard and strong metals. Magnetic steel can be synthesized from iron and aluminum, nickel, cobalt, etc., or synthesized from copper, niobium, tantalum. Here, only examples of the composition of magnetic steel are given, and it should not be understood as a limitation on the specific composition of magnetic steel.

[0040] For the above-mentioned rotor core 11, please refer to Figure 1 , a plurality of mounting grooves 111 are provided on the end face of the rotor core 11. The plurality of mounting grooves 111 are arranged at intervals along the circumferential direction of the rotor core 11. It can be understood that the mounting grooves 111 extend along the axial direction of the rotor core 11. The mounting groove 111 includes a first groove portion 1111. The first groove portion 1111 is rectangular, and the length direction of the first groove portion 1111 is perpendicular to the radial direction of the rotor core 11. Among them, the permanent magnet 12 is accommodated in the first groove portion 1111. That is, the permanent magnet 12 is arranged inside the rotor core 11. Compared with the rotor with surface-mounted magnetic tiles in the related art, the strength of the rotor assembly 1 can be improved, and the problem of rotor explosion of the motor 100 can be improved. It can be understood that when observing along the axial direction of the rotor core 11, the shape and size of the permanent magnet 12 are the same as those of the first groove portion 1111, that is, the permanent magnet 12 completely fills the first groove portion 1111, which is beneficial to improving the utilization rate of the first groove portion 1111.

[0041] Compared with the arc-shaped magnetic tiles, the rectangular permanent magnet 12 is easier to process, and the waste in the production process of the permanent magnet 12 can be reduced, and the material loss cost can be reduced.

[0042] In some embodiments, the number of the mounting grooves 111 is four.

[0043] In some embodiments, the diameter of the rotor core 11 is 29.3 mm to 30.6 mm, and specifically can be 30 mm.

[0044] In some embodiments, please refer to Figure 1 , the length of the first groove portion 1111 is L1, the width of the first groove portion 1111 is W1, and 5.74 < L1 / W1 < 6.05. By limiting the aspect ratio range of the first groove portion 1111, the rotor assembly 1 can simultaneously exhibit a relatively high efficiency and mechanical characteristics of the motor 100, and meet the structural strength requirements of the rotor assembly 1.

[0045] In some embodiments, L1 ranges from 17 mm to 17.5 mm, and specifically may be 17.2 mm.

[0046] In a specific embodiment, the distance between the first groove portion 1111 and the axis of the rotor core 11 is 8.75 mm.

[0047] In some embodiments, referring to Figure 1 , an arc chamfer 1113 is provided at the right angle of the first groove portion 1111.

[0048] In some embodiments, referring to Figure 1 , a glue groove 1114 is provided on the inner wall of the first groove portion 1111. The glue groove 1114 extends along the axial direction of the rotor core 11. The glue groove 1114 is used to fill glue to increase the connection strength between the permanent magnet 12 and the rotor core 11.

[0049] In some embodiments, referring to Figure 1 , the installation groove 111 further includes a second groove portion 1112. The second groove portion 1112 is communicated with the first groove portion 1111. The second groove portion 1112 is provided on one side of the first groove portion 1111 facing the outer edge of the rotor core 11. Along the length direction of the first groove portion 1111, the two second groove portions 1112 are flush with the two ends of the first groove portion 1111 respectively; the rotor assembly 1 further includes an adhesive, and the adhesive is filled in the second groove portion 1112. The second groove portion 1112 may be generally triangular; one side of the second groove portion 1112 close to the edge of the rotor core 11 may be a curve, and the curvature is the same as the curvature of the outer peripheral surface of the rotor core 11. The adhesive can bond the permanent magnet 12 to the rotor core 11, increase the connection strength between the permanent magnet 12 and the rotor core 11, and also increase the overall strength of the rotor assembly 1.

[0050] In some embodiments, the adhesive is made of non-ferromagnetic material. The non-ferromagnetic material has the characteristic of non-magnetic conduction, which can improve the problem of leakage magnetic flux of the permanent magnet 12. The adhesive can be epoxy resin AB glue, polyurethane AB glue, etc.

[0051] In some embodiments, referring to Figure 1 , the distance between the two second groove portions 1112 is L2, and 0.723 < L2 / L1 < 0.824. By limiting the ratio range between the distance of the two second groove portions 1112 and the length of the first groove portion 1111, the contact area between the permanent magnet 12 and the adhesive and the grooving area of the second groove portion 1112 can be limited within a suitable range, so that the rotor assembly 1 exhibits a relatively high structural strength.

[0052] In some embodiments, referring to Figure 1The outer edge of the rotor core 11, corresponding to the portion between any two adjacent first grooves 1111, is recessed inward to form a magnetic isolation bridge 112. It is understood that the magnetic isolation bridge 112 extends axially along the rotor core 11. The provision of the magnetic isolation bridge 112 can alleviate the problem of excessive magnetic leakage coefficient of the permanent magnets 12, which results in low utilization of the permanent magnets 12.

[0053] In some embodiments, see Figure 1 The inner surface of the magnetic isolation bridge 112 includes a first surface 1121 and a second surface 1122, both of which are parallel to the axis of the rotor core 11. The angle between the first surface 1121 and the second surface 1122 is α, where 80 degrees < α < 90 degrees. By limiting the range of the angle between the first surface 1121 and the second surface 1122, the cross-sectional area of the magnetic isolation bridge 112 and the thickness of the weak point of the outer wall of the first slot 1111 can be confined to a suitable range, thereby achieving both high structural strength and high utilization of the permanent magnets 12 in the rotor assembly 1.

[0054] Second, see Figures 2 to 4 The embodiment of the present application provides a motor 100, which includes a stator core 2 and a rotor assembly 1 as described above; the stator core 2 includes an annular stator yoke 21 and a plurality of stator teeth 22, the plurality of stator teeth 22 being arranged on the inner circumferential surface of the stator yoke 21, the plurality of stator teeth 22 being arranged at intervals along the circumference of the stator yoke 21, a stator slot 23 being formed between two adjacent stator teeth 22, and the plurality of stator teeth 22 defining a mounting cavity 24 coaxial with the stator yoke 21; the rotor assembly 1 is rotatably accommodated in the mounting cavity 24. It is understood that the stator teeth 22 are used for winding a winding, and the pitch of the winding can be 3, so that the motor 100 has a higher output power; the stator teeth 22 and the stator slots 23 both extend along the axial direction of the stator core 2. The motor 100 has the structural features and beneficial effects of the rotor assembly 1, which will not be repeated here.

[0055] In some embodiments, see Figure 4 The number of stator teeth 22 and the number of stator slots 23 are both 12.

[0056] In some embodiments, the inner walls of the stator slots 23 and both end surfaces of the stator core 2 are provided with insulating varnish.

[0057] In some embodiments, see Figure 4, the outer diameter of the stator yoke 21 is D1, the inner diameter of the mounting cavity 24 is D2, 52.3 mm < D1 < 53.6 mm, 0.564 < D2 / D1 < 0.592. By defining the ranges of the outer diameter of the stator yoke 21 and the inner diameter of the mounting cavity 24, the thickness of the stator core 2 can be made within a suitable range, enabling the stator core 2 to exhibit a relatively high efficiency and mechanical properties of the motor 100, and meeting the structural strength requirements of the stator core 2. Specifically, D2 can be 53 mm.

[0058] In some embodiments, refer to Figure 4 , the inner diameter of the stator yoke 21 is D3, 0.821 < D3 / D1 < 0.863. By defining the ratio range of the inner and outer diameters of the stator yoke 21, the thickness of the stator yoke 21 can be made within a suitable range, enabling the stator core 2 to exhibit a relatively high efficiency and mechanical properties of the motor 100, and meeting the structural strength requirements of the stator core 2.

[0059] In some embodiments, refer to Figure 4 , the tooth width of the stator tooth portion 22 is W2, 2.5 mm < W2 < 2.9 mm. The tooth width of the stator tooth portion 22 refers to the width of the root or middle part of the stator tooth portion 22 along the radial direction perpendicular to the stator yoke 21. By defining the range of the tooth width, the stator core 2 exhibits a relatively high structural strength and a relatively large cross-sectional area of the stator tooth slot 23, which is beneficial to meeting the structural strength of the stator core 2 and installing as many windings as possible, thereby reducing resistance and improving temperature rise.

[0060] In some embodiments, refer to Figure 5 , one end of the stator tooth portion 22 facing away from the stator yoke 21 includes a tooth boot 221, and an auxiliary groove 2211 is provided on a side of the tooth boot 221 facing away from the stator yoke 21, and the auxiliary groove 2211 extends along the axial direction of the stator core 2. By providing the auxiliary groove 2211 in the tooth boot 221, it is beneficial to weaken the cogging torque.

[0061] In some embodiments, refer to [[ID=第十九]] Figure 5 , along the circumferential direction of the stator yoke 21, the auxiliary groove 2211 is located in the middle of the tooth boot 221. The middle of the tooth boot 221 is the peak of the cogging torque. By arranging the auxiliary groove 2211 in the middle of the tooth boot 221, it is beneficial to weaken the peak of the cogging torque.

[0062] In some embodiments, refer to Figure 5, the width of the auxiliary groove 2211 is W3, the depth of the auxiliary groove 2211 is H1, 1.90

[0063] In some embodiments, W3 is 1.45 mm to 1.50 mm, and specifically may be 1.47 mm.

[0064] In some embodiments, see Figure 2 and Figure 3 The motor 100 further includes a housing 3, a front cover 4, a rear cover 5, a bearing 6, and a rotating shaft 7. The housing 3 is cylindrical, and the stator core 2 is installed in the housing 3 and has an interference fit with the housing 3. The front cover 4 and the rear cover 5 respectively cover the openings at both ends of the housing 3, and both the front cover 4 and the rear cover 5 are provided with bearings 6. The rotating shaft 7 passes through the rotor core 11, and the two ends of the rotating shaft 7 respectively pass through the bearings 6 of the front cover 4 and the rear cover 5, thereby rotatably mounting the rotor core 11 in the mounting cavity 24 of the stator core 2. Among them, a through hole is provided in the center of the front cover 4, and one end of the rotor extends out of the through hole.

[0065] In some embodiments, see Figure 2 and Figure 3 The motor 100 further includes a rotor end plate 8 , and two rotor end plates 8 are respectively arranged at both ends of the rotor core 11 , which is beneficial to further fix the permanent magnet 12 and improve the problem of the permanent magnet 12 escaping from the first groove portion 1111 .

[0066] In a specific embodiment, a motor 100 from the related art was compared with a motor 100 from an embodiment of the present application at a test temperature of 150°C. The rotor of the related art used a surface-mounted magnetic tile rotor. The test results showed that the maximum speed of the rotor assembly 1 of the present application was 10% higher than that of the rotor of the related art. This indicates that the rotor assembly 1 of the embodiment of the present application has improved strength, resulting in better mechanical properties and motor 100 efficiency.

[0067] In a specific embodiment, a motor 100 of the related art is compared with the motor 100 of the embodiment of the present application. The test results are as follows: Figures 6 to 8 shown.

[0068] Figure 6 ​The cogging torque comparison diagram of the motor 100 of the embodiment of the present application and the motor 100 of the related art is shown in the figure. The solid line in the figure is the cogging torque of the motor 100 of the embodiment of the present application, and the dotted line is the cogging torque of the motor 100 of the related art. The horizontal axis is the electrical angle [deg], and the vertical axis is the torque [N / m]. Figure 6 It can be seen that the waveform of the cogging torque is smoother and the peak is smaller than that of the dotted line, that is, compared with the motor 100 of the related art, the motor 100 of the embodiment of the present application weakens the cogging torque.

[0069] Figure 7 : is a torque comparison diagram of the motor 100 of the embodiment of the present application and the motor 100 of the related art. In the figure, the solid line is the torque of the motor 100 of the embodiment of the present application, the dotted line is the torque of the motor 100 of the related art, the horizontal axis is the speed [rpm], and the vertical axis is the torque [N / m]. Figure 7 It can be seen that the solid line is straighter than the dotted line, that is, compared with the motor 100 of the related art, the torque change of the motor 100 of the embodiment of the present application is smoother, which also weakens the influence of the cogging torque on the torque.

[0070] Figure 8 : is a temperature comparison diagram of the motor 100 of the embodiment of the present application and the motor 100 of the related art. In the figure, the solid line is the temperature of the motor 100 of the embodiment of the present application, the dotted line is the temperature of the motor 100 of the related art, the horizontal axis is time [s], and the vertical axis is temperature [°C]. Figure 8 It can be seen from the figure that the solid line has a lower temperature than the dotted line at the same time, that is, the motor 100 of the embodiment of the present application has an improved temperature rise compared to the motor 100 of the related art.

[0071] The rotor assembly 1 and motor 100 of the present invention, by accommodating the permanent magnet 12 in the first slot 1111, can improve the strength of the rotor assembly 1 and alleviate the problem of rotor explosion of the motor 100. By limiting the range of the aspect ratio of the first slot 1111 and the ratio of the spacing between the two second slots 1112 to the length of the first slot 1111, the efficiency and mechanical properties of the motor 100 of the rotor assembly 1 can be maintained within a suitable range while meeting the structural strength requirements of the rotor assembly 1. By limiting the range of the angle between the first surface 1121 and the second surface 1122, the rotor assembly 1 can simultaneously exhibit high structural strength and utilization of the permanent magnet 12. By limiting the range of the outer diameter of the stator yoke 21 and the inner diameter of the mounting cavity 24, and the range of the ratio of the inner and outer diameters of the stator yoke 21, the stator core 2 can simultaneously exhibit high efficiency and mechanical properties of the motor 100 while meeting the structural strength requirements of the stator core 2. By limiting the range of the tooth width, it is beneficial to meet the structural strength of the stator core 2 and install as many windings as possible, reduce resistance, and improve temperature rise. The auxiliary groove 2211 is arranged in the middle of the tooth shoe 221 to reduce the peak of the cogging torque. The depth-to-width ratio of the auxiliary groove 2211 is limited so that the auxiliary groove 2211 has a high reduction effect on the cogging torque and meets the structural strength requirements of the tooth shoe 221.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A rotor assembly, characterized in that: include: The rotor core has a plurality of mounting grooves provided on its end surface, the plurality of mounting grooves being spaced apart along the circumference of the rotor core; the mounting grooves including a first groove portion, the first groove portion being rectangular, the length direction of the first groove portion being perpendicular to the radial direction of the rotor core; a permanent magnet, housed in the first slot; The length of the first groove portion is L1, the width of the first groove portion is W1, and the width of the first groove portion is 5.74 <L1 / W1<6.05。 2. The rotor assembly according to claim 1, wherein: The mounting slot further includes a second slot portion, the second slot portion being connected to the first slot portion, the second slot portion being arranged on a side of the first slot portion facing the outer edge of the rotor core, and along the length direction of the first slot portion, the two second slot portions are respectively flush with both ends of the first slot portion; The rotor assembly further includes an adhesive, wherein the adhesive is filled in the second groove portion; Wherein, the adhesive is made of non-ferromagnetic material.

3. The rotor assembly according to claim 2, wherein: The distance between the two second grooves is L2, 0.723 <L2 / L1<0.824。 4. The rotor assembly according to any one of claims 1 to 3, characterized in that: The outer edge of the rotor core is recessed inwardly at a portion corresponding to a portion between any two adjacent first grooves to form a magnetic isolation bridge, wherein an inner surface of the magnetic isolation bridge includes a first surface and a second surface, and both the first surface and the second surface are parallel to the axis of the rotor core; The included angle between the first surface and the second surface is α, and 80 degrees < α < 90 degrees.

5. A motor, characterized in that: include: A stator core comprising an annular stator yoke and a plurality of stator teeth, wherein the plurality of stator teeth are provided on an inner circumferential surface of the stator yoke, the plurality of stator teeth are spaced apart along the circumference of the stator yoke, a stator tooth slot is formed between two adjacent stator teeth, and the plurality of stator teeth define a mounting cavity coaxial with the stator yoke; The rotor assembly according to any one of claims 1 to 4, wherein the rotor assembly is rotatably received in the mounting cavity.

6. The motor according to claim 5, characterized in that The outer diameter of the stator yoke is D1, and the inner diameter of the mounting cavity is D2, 52.3 mm. <D1<53.6mm,0.564<D2 / D1<0.592。 7. The motor according to claim 6, characterized in that The inner diameter of the stator yoke is D3, 0.821 <D3 / D1<0.863。 8. The motor according to claim 5, characterized in that The tooth width of the stator teeth is W2, 2.5 mm <W2<2.9mm。 9. The motor according to any one of claims 5 to 8, characterized in that One end of the stator tooth portion facing away from the stator yoke portion includes a tooth shoe, and a side of the tooth shoe facing away from the stator yoke portion is provided with an auxiliary slot, and the auxiliary slot extends along the axial direction of the stator core.

10. The motor according to claim 9, characterized in that Along the circumference of the stator yoke, the auxiliary groove is located in the middle of the tooth shoe; and / or, The width of the auxiliary groove is W3, the depth of the auxiliary groove is H1, 1.90 <H1 / W3<2.10。

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