Motor shaft, rotor assembly and motor

Abstract

The utility model discloses a motor shaft, a rotor assembly and a motor, the motor shaft comprises a shaft body, the shaft body is provided with a knurling groove, the knurling groove extends along the circumferential direction of the shaft body to form a ring shape, the bottom wall of the knurling groove is provided with a plurality of knurling teeth, and the maximum outer diameter of the knurling groove provided with the knurling teeth is smaller than the outer diameter of the shaft body; wherein the diameter d of the knurling grooves, the diameter D of the shaft body and the tooth height h of the knurling teeth meet the condition that d is larger than or equal to D-3h and smaller than or equal to D-1. 5h. According to the motor shaft provided by the utility model, the maximum outer diameter of the part of the knurling groove provided with the knurling teeth is smaller than the outer diameter of the shaft body, when the motor shaft is machined and manufactured, the knurling groove can be firstly cut, then the knurling teeth are machined on the bottom wall of the knurling groove in a reduced material mode, and finally, after the knurling groove is clamped by a machine tool, the outer surface of the shaft body is subjected to accurate grinding and the like. The risk that the motor shaft jumps greatly is effectively reduced, the operation reliability of the motor is effectively improved, the diameter of the knurling groove can be prevented from being too large, and clamping of the knurling groove by a machine tool is prevented from being affected.

Description

Technical Field

[0001] The utility model mainly relates to the technical field of motors, in particular to a motor shaft, a rotor assembly and a motor. Background Art

[0002] The motor shaft is a key component for the motor to achieve electromechanical energy conversion, and its bonding force and shaft runout are key elements in the design. In the production process of existing motor shafts, the problem of excessive runout is likely to occur, resulting in eccentricity and abnormal vibration during the operation of the motor, seriously affecting the operation reliability of the motor. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a motor shaft, which can avoid the diameter of the knurled groove being too large, avoid affecting the clamping of the knurled groove by the machine tool, and clamp the knurled groove to process the outer surface of the shaft body after processing the knurled teeth, effectively reducing the risk of excessive runout of the motor shaft.

[0004] The utility model also provides a rotor assembly, which includes the above-mentioned motor shaft.

[0005] The utility model also provides a motor, which includes the above-mentioned rotor assembly.

[0006] The motor shaft according to the embodiment of the utility model includes a shaft body, on which a knurled groove is provided. The knurled groove extends circumferentially along the shaft body to form a ring. A plurality of knurled teeth are provided on the bottom wall of the knurled groove. The maximum outer diameter of the knurled groove at the position where the knurled teeth are provided is smaller than the outer diameter of the shaft body. Wherein, for the diameter d of the knurled groove, the diameter D of the shaft body and the tooth height h of the knurled teeth, it satisfies: D - 3h ≤ d ≤ D - 1.5h.

[0007] The motor shaft according to the embodiment of the utility model, by providing a knurled groove on the shaft body, and a plurality of knurled teeth are provided on the bottom wall of the knurled groove. The knurled teeth can increase the friction force between other components and the motor shaft, preventing the motor shaft from slipping radially during operation. The maximum outer diameter of the knurled groove at the position where the knurled teeth are provided is smaller than the outer diameter of the shaft body. When manufacturing the motor shaft, the knurled groove can be cut first, then the knurled teeth can be machined by reducing the material on the bottom wall of the knurled groove, and finally the outer surface of the shaft body can be precision ground after the machine tool clamps the knurled groove, effectively reducing the risk of excessive runout of the motor shaft. The shaft runout can be controlled within 0.01 mm, effectively improving the operation reliability of the motor. And for the diameter d of the knurled groove, the diameter D of the shaft body and the tooth height h of the knurled teeth, it satisfies: D - 3h ≤ d ≤ D - 1.5h, which can avoid the diameter of the knurled groove being too small and affecting the strength of the motor after machining the knurled teeth; it can avoid the diameter of the knurled groove being too large, avoiding affecting the clamping of the knurled groove by the machine tool and affecting the machining of the outer surface of the shaft body.

[0008] In some embodiments of the present utility model, a plurality of the knurled teeth are straight-knurled teeth.

[0009] In some embodiments of the present utility model, each of the knurled teeth extends along the axial direction of the shaft body, and the plurality of knurled teeth are arranged at intervals along the circumferential direction of the shaft body.

[0010] In some embodiments of the present utility model, each of the knurled teeth extends circumferentially along the shaft body to form a ring, and the plurality of knurled teeth are arranged at intervals along the axial direction of the shaft body.

[0011] In some embodiments of the present utility model, a plurality of the knurled teeth are formed into a mesh knurling.

[0012] In some embodiments of the present utility model, in the direction radially outward of the shaft body, the inner walls of the two opposite sides of the knurling groove along the axial direction of the shaft body are inclined away from each other.

[0013] In some embodiments of the present utility model, along the axial direction of the shaft body, the knurled teeth are spaced from the side walls of the knurling groove.

[0014] The rotor assembly according to an embodiment of the present utility model includes the above-mentioned motor shaft and a rotor, the rotor is sleeved on the motor shaft and is engaged with the knurled teeth.

[0015] For the rotor assembly according to an embodiment of the present utility model, by providing a knurling groove on the shaft body, a plurality of knurled teeth are provided on the bottom wall of the knurling groove. The knurled teeth can increase the friction between other components and the motor shaft, and prevent the motor shaft from slipping radially during operation. The maximum outer diameter of the knurling groove where the knurled teeth are provided is smaller than the outer diameter of the shaft body. When manufacturing the motor shaft, the knurling groove can be first cut, then the knurled teeth can be machined by reducing the material on the bottom wall of the knurling groove, and finally the outer surface of the shaft body can be precision ground after the machine tool clamps the knurling groove. The risk of excessive runout of the motor shaft is effectively reduced, and the shaft runout can be controlled within 0.01 mm, effectively improving the reliability of motor operation. And the diameter d of the knurling groove, the diameter D of the shaft body, and the tooth height h of the knurled teeth satisfy: D - 3h ≤ d ≤ D - 1.5h, which can avoid the diameter of the knurling groove being too small and affecting the strength of the motor after the knurled teeth are processed; it can avoid the diameter of the knurling groove being too large and affecting the clamping of the knurling groove by the machine tool and the machining of the outer surface of the shaft body.

[0016] In some embodiments of the present utility model, the rotor is a plastic-coated rotor.

[0017] The motor according to an embodiment of the present utility model includes a housing, a stator assembly, and a rotor assembly. The stator assembly is disposed inside the housing; the rotor is disposed inside the housing, at least a part of the motor shaft extends out of the housing, and the rotor assembly is sleeved outside the stator assembly, or the stator assembly is sleeved outside the rotor assembly.

[0018] For the motor according to an embodiment of the present utility model, by providing a knurled groove on the shaft body, a plurality of knurled teeth are provided on the bottom wall of the knurled groove. The knurled teeth can increase the friction between other components and the motor shaft, preventing the motor shaft from slipping radially during operation. The maximum outer diameter of the knurled groove at the position where the knurled teeth are provided is smaller than the outer diameter of the shaft body. When manufacturing the motor shaft, the knurled groove can be cut first, then the knurled teeth can be machined by reducing the material on the bottom wall of the knurled groove, and finally, after the machine tool clamps the knurled groove, the outer surface of the shaft body can be finely ground and other processes are carried out, effectively reducing the risk of excessive runout of the motor shaft. The shaft runout can be controlled within 0.01 mm, effectively improving the reliability of the motor operation. And the diameter d of the knurled groove, the diameter D of the shaft body, and the tooth height h of the knurled teeth satisfy: D - 3h ≤ d ≤ D - 1.5h, which can avoid the diameter of the knurled groove being too small and affecting the strength of the motor after the knurled teeth are processed; it can avoid the diameter of the knurled groove being too large, avoiding affecting the clamping of the knurled groove by the machine tool and affecting the processing of the outer surface of the shaft body.

[0019] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0021] Figure 1 is the front view of the motor shaft according to an embodiment of the present utility model;

[0022] Figure 2 is Figure 1 the enlarged view of part A in

[0023] REFERENCE SIGNS:

[0024] 100, motor shaft;

[0025] 1, shaft body; 11, knurled groove; 12, knurled teeth; 13, clamping groove; 14, non-circular part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0027] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present utility model 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 should not be construed as a limitation of the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise stated, the meaning of "a plurality" is two or more.

[0028] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0029] Reference will be made below Figure 1 and Figure 2 to describe the motor shaft 100 according to an embodiment of the present utility model.

[0030] As Figure 1 shown, the motor shaft 100 according to an embodiment of the present utility model includes a shaft body 1.

[0031] Specifically, the motor shaft 100 is passed through the central hole of the rotor, which is convenient for realizing the connection and power transmission between the motor shaft 100 and the rotor, so that the motor shaft 100 can drive the rotor to rotate together when rotating, thereby generating electromagnetic induction or mechanical energy conversion, enabling the motor to efficiently convert electrical energy into rotational mechanical energy, and thus driving various mechanical equipment to operate.

[0032] As Figure 1 and Figure 2As shown in the figure, a knurling groove 11 is provided on the shaft body 1. The knurling groove 11 extends circumferentially along the shaft body 1 to form a ring shape. A plurality of knurling teeth 12 are provided on the bottom wall of the knurling groove 11. The maximum outer diameter of the knurling groove 11 where the knurling teeth 12 are provided is smaller than the outer diameter of the shaft body 1. For example, when the rotor is sleeved on the knurling groove 11, the knurling teeth 12 can increase the friction between the rotor and the motor shaft 100, preventing radial slippage between the motor shaft 100 and the rotor during operation.

[0033] When manufacturing the motor shaft 100, the knurling groove 11 can be cut first, and then the knurling teeth 12 can be machined by reducing the material on the bottom wall of the knurling groove 11. Among them, when the knurling teeth 12 are extruded, the knurling teeth 12 may expand outward. The maximum outer diameter of the knurling groove 11 where the knurling teeth 12 are provided is smaller than the outer diameter of the shaft body 1. Finally, after the machine tool clamps the knurling groove 11, finishing processes such as precision grinding of the outer surface of the shaft body 1 are carried out, effectively reducing the risk of excessive runout of the motor shaft 100. The shaft runout can be controlled within 0.01 mm, effectively improving the reliability of motor operation.

[0034] Among them, the diameter d of the knurling groove 11, the diameter D of the shaft body 1, and the tooth height h of the knurling teeth 12 satisfy: D - 3h ≤ d ≤ D - 1.5h. The diameter d of the knurling groove 11 not being less than D - 3h can prevent the diameter of the knurling groove 11 from being too small, avoiding affecting the strength of the motor after the knurling teeth 12 are processed; the diameter d of the knurling groove 11 not being greater than D - 3h can prevent the diameter of the knurling groove 11 from being too large, avoiding affecting the clamping of the knurling groove 11 by the machine tool and avoiding affecting the processing of the outer surface of the shaft body 1.

[0035] According to the motor shaft 100 of the embodiment of the present invention, by providing a knurling groove 11 on the shaft body 1, a plurality of knurling teeth 12 are provided on the bottom wall of the knurling groove 11. The knurling teeth 12 can increase the friction between other components and the motor shaft 100, preventing radial slippage of the motor shaft 100 during operation. The maximum outer diameter of the knurling groove 11 where the knurling teeth 12 are provided is smaller than the outer diameter of the shaft body 1. When manufacturing the motor shaft 100, the knurling groove 11 can be cut first, and then the knurling teeth 12 can be machined by reducing the material on the bottom wall of the knurling groove 11. Finally, after the machine tool clamps the knurling groove 11, finishing processes such as precision grinding of the outer surface of the shaft body 1 are carried out, effectively reducing the risk of excessive runout of the motor shaft 100. The shaft runout can be controlled within 0.01 mm, effectively improving the reliability of motor operation. And the diameter d of the knurling groove 11, the diameter D of the shaft body 1, and the tooth height h of the knurling teeth 12 satisfy: D - 3h ≤ d ≤ D - 1.5h, which can prevent the diameter of the knurling groove 11 from being too small, avoiding affecting the strength of the motor after the knurling teeth 12 are processed; it can prevent the diameter of the knurling groove 11 from being too large, avoiding affecting the clamping of the knurling groove 11 by the machine tool and avoiding affecting the processing of the outer surface of the shaft body 1.

[0036] In some embodiments of the present invention, the plurality of knurled teeth 12 are straight knurled teeth, and the plurality of knurled teeth 12 can form clear and uniform straight patterns, thereby improving the aesthetics and texture of the surface of the motor shaft 100, and the motor shaft 100 has a high degree of finish. In addition, the portion of the motor shaft 100 surface provided with the knurled teeth 12 has more lines and concave-convex structures, which can significantly increase the friction with other components and improve the stability and reliability of the connection.

[0037] Furthermore, each knurled tooth 12 is disposed along the axial direction of the shaft body 1 (eg Figure 1 The plurality of knurled teeth 12 are arranged at intervals along the circumferential direction of the shaft body 1, thereby increasing the friction force on the surface of the motor shaft 100, preventing slipping, and having a certain decorative effect.

[0038] Furthermore, each knurled tooth 12 extends in a ring shape along the circumferential direction of the shaft body 1, and multiple knurled teeth 12 are arranged at intervals along the axial direction of the shaft body 1, thereby enhancing the friction force of the motor shaft 100 in the axial direction and avoiding axial displacement of the knurled teeth 12 mating parts.

[0039] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, multiple knurled teeth 12 are formed into mesh knurling, and multiple knurled teeth 12 present a mesh texture on the surface of the motor shaft 100. The mesh knurling can cover a larger surface area of ​​the knurling groove 11, so that the overall texture of the top circle is improved. The axial binding force of the mesh knurling is increased by 3-4 times compared with the traditional knurling, and the tangential binding force is increased by 1.5-2 times. The outer surface friction of the shaft body 1 at the knurling groove 11 is good, which increases the reliability of the matching of the motor shaft 100. And after the rotor has been frequently fatigued and impacted, the connection between the rotor and the motor shaft 100 can still remain intact, greatly enhancing its service life.

[0040] In some embodiments of the utility model, in the radially outward direction of the shaft body 1, the two inner walls of the knurled groove 11 opposite to each other along the axial direction of the shaft body 1 are inclined away from each other. Compared with the step surface of right angles or complex shapes, the two inner walls of the knurled groove 11 opposite to each other along the axial direction of the shaft body 1 with inclined transition are simpler to process and manufacture, which can reduce the processing steps and costs. And it can avoid the occurrence of sharp corners on the two inner walls of the knurled groove 11 opposite to each other along the axial direction of the shaft body 1. When the motor shaft 100 is subjected to external force, the two inner walls of the inclined knurled groove 11 opposite to each other along the axial direction of the shaft body 1 can adapt to the deformation of the motor shaft 100 to a certain extent, reducing the stress and damage caused by the deformation.

[0041] In some embodiments of the present invention, Figure 1 and Figure 2As shown, along the axial direction of the shaft body 1, the knurled teeth 12 are spaced from the side walls of the knurled grooves 11, and machining allowances can be left at both ends of the knurled grooves 11 in the axial direction when machining the knurled teeth 12 to ensure the machining effect of the knurled teeth 12.

[0042] In some embodiments of the present utility model, as Figure 1 shown, an annular clamping groove 13 is provided on one side in the axial direction of the motor shaft 100, and quick fastening is achieved through a snap ring or the like to prevent the rotor on the motor shaft 100 from axially moving. The installation and disassembly of the motor shaft 100 and the rotor are relatively convenient.

[0043] In some embodiments of the present utility model, chamfers are provided at both ends of the motor shaft 100 in the axial direction to avoid sharp corners at both ends of the motor shaft 100 in the axial direction and prevent situations such as cracking or scratching of assembly workers and users and maintenance personnel.

[0044] The rotor assembly according to an embodiment of the present utility model includes the above-mentioned motor shaft 100 and a rotor. The rotor is sleeved on the motor shaft 100 and cooperates with the knurled teeth 12. The knurled teeth 12 enhance the cooperation force between the motor shaft 100 and the rotor and achieve reliable connection, so that the motor shaft 100 can drive the rotor to rotate together when rotating, thereby generating electromagnetic induction or mechanical energy conversion, enabling the motor to efficiently convert electrical energy into rotational mechanical energy, and thus driving various mechanical equipment to operate.

[0045] The rotor assembly according to an embodiment of the present utility model is provided with knurled grooves 11 on the shaft body 1. A plurality of knurled teeth 12 are provided on the bottom wall of the knurled grooves 11. The knurled teeth 12 can increase the friction force between other components and the motor shaft 100 and prevent the motor shaft 100 from radially slipping during operation. The maximum outer diameter of the knurled grooves 11 where the knurled teeth 12 are provided is smaller than the outer diameter of the shaft body 1. When machining and manufacturing the motor shaft 100, the knurled grooves 11 can be first cut, then the knurled teeth 12 can be machined by reducing the material on the bottom wall of the knurled grooves 11, and finally, after the knurled grooves 11 are clamped by the machine tool, processes such as precision grinding of the outer surface of the shaft body 1 are carried out, effectively reducing the risk of excessive runout of the motor shaft 100. The shaft runout can be controlled within 0.01 mm, effectively improving the operating reliability of the motor. And the diameter d of the knurled grooves 11, the diameter D of the shaft body 1, and the tooth height h of the knurled teeth 12 satisfy: D - 3h ≤ d ≤ D - 1.5h, which can avoid the diameter of the knurled grooves 11 being too small and affecting the strength of the motor after machining the knurled teeth 12; it can avoid the diameter of the knurled grooves 11 being too large and affecting the clamping of the knurled grooves 11 by the machine tool and affecting the machining of the outer surface of the shaft body 1.

[0046] In some embodiments of the present utility model, the rotor is a plastic-coated rotor. The outer surface of the plastic-coated rotor is covered with plastic, which can effectively prevent moisture erosion, thereby extending the service life of the rotor assembly. The noise generated by the plastic-coated rotor during use is lower than that of traditional rotors, which helps to reduce noise pollution and improve the working environment. The plastic-coated rotor has good electrical insulation performance, which helps to reduce energy loss during the operation of the motor and improve energy utilization efficiency.

[0047] The motor according to the embodiment of the present utility model includes a housing, a stator assembly, and the above-mentioned rotor assembly. The stator assembly is disposed inside the housing; the rotor is disposed inside the housing, at least part of the motor shaft 100 extends out of the housing, and the rotor assembly is sleeved outside the stator assembly, or the stator assembly is sleeved outside the rotor assembly.

[0048] It can be understood that when the rotor assembly is sleeved outside the stator assembly, the motor is an outer-rotor motor. The outer-rotor motor has a larger moment of inertia and can provide a larger torque, which is suitable for scenarios that require a larger driving force. The motor has higher efficiency when directly driving a load. When the stator assembly is sleeved outside the rotor assembly, the motor is an inner-rotor motor. The outer shell and the stator of the inner-rotor motor can be integrally designed, which helps to ensure the strength and stiffness of the motor; the two ends of the rotor assembly are usually supported by end caps, further enhancing the structural stability.

[0049] In the motor according to the embodiment of the present utility model, by providing a knurled groove 11 on the shaft body 1, a plurality of knurled teeth 12 are provided on the bottom wall of the knurled groove 11. The knurled teeth 12 can increase the friction between other components and the motor shaft 100, preventing the motor shaft 100 from slipping radially during operation. The maximum outer diameter of the knurled groove 11 at the position where the knurled teeth 12 are provided is smaller than the outer diameter of the shaft body 1. When manufacturing the motor shaft 100, the knurled groove 11 can be first cut, then the knurled teeth 12 can be machined by reducing the material on the bottom wall of the knurled groove 11, and finally the outer surface of the shaft body 1 can be finish-ground after the knurled groove 11 is clamped by the machine tool. The risk of excessive runout of the motor shaft 100 is effectively reduced, and the shaft runout can be controlled within 0.01 mm, effectively improving the running reliability of the motor. And the diameter d of the knurled groove 11, the diameter D of the shaft body 1, and the tooth height h of the knurled teeth 12 satisfy: D - 3h ≤ d ≤ D - 1.5h, which can avoid the diameter of the knurled groove 11 being too small and affecting the strength of the motor after the knurled teeth 12 are processed; it can avoid the diameter of the knurled groove 11 being too large, avoiding affecting the clamping of the knurled groove 11 by the machine tool and affecting the processing of the outer surface of the shaft body 1.

[0050] In some embodiments of the present utility model, the motor is connected to a load. A non-circular portion 14 is provided on the part of the motor shaft 100 that extends out of the housing. The non-circular portion 14 is fixedly connected to the load, facilitating the connection and power transmission between the load, the motor shaft 100, and the rotor.

[0051] The motor shaft 100, the rotor assembly, and other components and operations of the motor according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

[0052] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0053] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A motor shaft, characterized in that: include: A shaft body, wherein the shaft body is provided with a knurled groove, the knurled groove extends in a ring shape along the circumferential direction of the shaft body, a plurality of knurled teeth are provided on the bottom wall of the knurled groove, and the maximum outer diameter of the knurled groove where the knurled teeth are provided is smaller than the outer diameter of the shaft body; Wherein, the diameter d of the knurling groove, the diameter D of the shaft body and the tooth height h of the knurling tooth satisfy: D-3h≤d≤D-1.5h.

2. The motor shaft according to claim 1, characterized in that: The plurality of knurled teeth are all straight knurled teeth.

3. The motor shaft according to claim 2, characterized in that: Each of the knurled teeth extends along the axial direction of the shaft body, and a plurality of the knurled teeth are arranged at intervals along the circumferential direction of the shaft body.

4. The motor shaft according to claim 2, characterized in that: Each of the knurled teeth extends in a ring shape along the circumferential direction of the shaft body, and a plurality of the knurled teeth are arranged at intervals along the axial direction of the shaft body.

5. The motor shaft according to claim 1, characterized in that: The plurality of knurling teeth are formed into a mesh knurling.

6. The motor shaft according to claim 1, characterized in that: In the radially outward direction of the shaft body, two inner walls of the knurling groove that are opposite to each other in the axial direction of the shaft body are inclined away from each other.

7. The motor shaft according to claim 1, characterized in that: Along the axial direction of the shaft body, the knurling teeth are spaced apart from the side walls of the knurling grooves.

8. A rotor assembly, characterized in that: include: The motor shaft according to any one of claims 1 to 7; A rotor is sleeved on the motor shaft and matched with the knurled teeth.

9. The rotor assembly according to claim 8, characterized in that The rotor is a plastic-coated rotor.

10. A motor, characterized in that: include: case; A stator assembly, wherein the stator assembly is disposed in the housing; According to the rotor assembly according to claim 8 or 9, the rotor is arranged in the housing, at least a portion of the motor shaft extends out of the housing, and the rotor assembly is sleeved outside the stator assembly, or the stator assembly is sleeved outside the rotor assembly.

Images