Electric motor and robot

Abstract

Provided in the present application are an electric motor and a robot. The electric motor comprises: a brake rotor and a rotating shaft, wherein the brake rotor is provided with a mounting hole, and the rotating shaft is inserted into the mounting hole. In the direction in which the rotating shaft is mounted in the mounting hole, a knurled portion and an accommodating groove are sequentially provided on the rotating shaft, the knurled portion being arranged adjacent to the accommodating groove; the maximum distance between the axis of the rotating shaft and the knurled portion is greater than the radius of the mounting hole, such that at least part of the knurled portion is embedded into the inner wall of the mounting hole. Part of the knurled portion being embedded into the inner wall of the mounting hole achieves circumferential fixation of the rotating shaft and the brake rotor, enabling the brake rotor and the rotating shaft to rotate synchronously, and thereby eliminating the need for additional components to transmit torque between the brake rotor and the rotating shaft; the number of mounting parts of the electric motor is reduced, and the mounting process of the electric motor is simplified.

Description

Motors and robots

[0001] This application claims priority to Chinese Patent Application No. 2025104963088, filed with the Chinese Patent Office on April 18, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of motor technology, and more specifically, to a motor and a robot. Background Technology

[0003] For motor brakes, the brake rotor and shaft are usually fixed by a flat key or set screw, so that torque can be transmitted between the brake rotor and shaft. However, using flat keys and set screws as fixing components results in more installation components and installation procedures for the motor. Technical solutions

[0004] This application aims to solve one of the technical problems existing in the prior art or related technologies.

[0005] In view of this, in a first aspect, this application proposes an electric motor, comprising: a brake rotor having a mounting hole; a shaft inserted into the mounting hole, wherein a knurled portion and a receiving groove are sequentially provided on the shaft along the direction of mounting to the mounting hole, the knurled portion and the receiving groove being arranged adjacent to each other, and the maximum distance between the axis of the shaft and the knurled portion being greater than the radius of the mounting hole, so that at least a portion of the knurled portion is embedded in the inner wall of the mounting hole.

[0006] During the knurling process of cutting the inner wall of the mounting hole, chips are generated. These chips can accumulate in the receiving groove. In this design, a receiving groove is set on the adjacent side of the knurling part. In the direction of shaft installation into the mounting hole, the knurling part and the receiving groove are arranged sequentially. During the installation of the shaft and brake rotor, the chips cut by the knurling part will fall into the receiving groove in front. The receiving groove accommodates the chips, preventing the shaft from being squeezed by the accumulated chips, thus avoiding deformation of the shaft due to compression. In this design, the receiving groove provides space for the chips, preventing the chips from squeezing the shaft, thereby ensuring sufficient accuracy of the shaft. After the knurling part cuts the inner wall of the mounting hole, a part of the knurling part is embedded in the inner wall of the mounting hole. At this time, the shaft and brake rotor are fixed in the circumferential direction, and the brake rotor and shaft can rotate synchronously. No additional parts are needed to achieve torque transmission between the brake rotor and shaft, reducing the number of motor mounting components and simplifying the motor installation process.

[0007] In some technical solutions, optionally, the volume of the knurled part embedded in the inner wall of the mounting hole is smaller than the volume of the receiving groove.

[0008] The volume of the knurled part embedded in the inner wall of the mounting hole is the volume of the removed chips. In this solution, the volume of the knurled part embedded in the inner wall of the mounting hole is limited to less than the volume of the receiving groove. This means that the volume of the removed chips is less than the volume of the receiving groove, ensuring that the volume of the receiving groove is sufficient to accommodate the removed chips and avoid the chips from exerting pressure on the rotating shaft.

[0009] In some technical solutions, optionally, the volume of the knurled part embedded in the inner wall of the mounting hole is V1, and the volume of the receiving groove is V2, where V2≥1.1×V1.

[0010] In this design, the volume of the inner wall of the knurled part embedded in the mounting hole is defined as V1, that is, the volume of the removed chips is V1. The volume of the removed chips and the volume of the receiving groove satisfy the following condition: V2 ≥ 1.1 × V1. After the chips are removed and fall into the receiving groove, the chips will not be completely stacked in the receiving groove, so there will be gaps between the chips. The volume of the receiving groove and the volume of the chips satisfy the above range. Even if there are gaps between the chips, the receiving groove can effectively accommodate the chips and avoid the chips exerting pressure on the rotating shaft.

[0011] In some technical solutions, optionally, along the axial direction of the shaft, the sum of the length of the knurled portion and the length of the receiving groove is less than the length of the brake rotor.

[0012] If the receiving slot extends beyond the brake rotor, the chips will fall to the outside of the brake rotor. Furthermore, if the receiving slot is not cleaned properly, the chips inside the receiving slot may fall outwards as the motor is used, resulting in chips inside the motor and affecting the quality of the motor.

[0013] In some technical solutions, optionally, the rotating shaft includes a guide portion and a shaft body, the radius of the guide portion is larger than the radius of the shaft body, and along the axial direction of the rotating shaft, a receiving groove is located between the knurled portion and the guide portion, the guide portion is clearance-fitted with the mounting hole, and the distance between the guide portion and the inner wall of the mounting hole is W, 0.005mm≤W≤0.05mm.

[0014] A portion of the shaft structure serves as a guide. Along the shaft's axial direction, a receiving groove is located between the knurled portion and the guide portion. In the direction of shaft installation into the mounting hole, the knurled portion, receiving groove, and guide portion are arranged sequentially. Therefore, during the installation of the shaft and brake rotor, the guide portion extends into the mounting hole before the receiving groove. The guide portion has a larger radius than the shaft body. It engages with the inner wall of the mounting hole at a distance, guiding the shaft's installation process and ensuring the correct pressing direction of the knurled portion as it embeds into the inner wall of the mounting hole. This prevents tilting during shaft installation, ensures the installation accuracy of the shaft and brake rotor, and prevents uneven brake air gap.

[0015] In some technical solutions, the rotating shaft may optionally include a limiting part, the limiting part and the guide part being located on both sides of the knurled part along the axial direction; the brake rotor is provided with a limiting groove, at least a portion of the limiting part extending into the limiting groove, and the limiting part abutting against the inner wall of the limiting groove along the axial direction of the rotating shaft.

[0016] A limiting part is provided on the rotating shaft, and a limiting groove is provided at one axial end of the brake rotor. During the process of installing the rotating shaft into the mounting hole, when the limiting part abuts against the inner wall of the limiting groove along the axial direction of the rotating shaft, it indicates that the rotating shaft has been installed in place. At this time, the limiting groove limits the limiting part to prevent the rotating shaft from continuing to move relative to the brake rotor along the axial direction.

[0017] In this embodiment, the radius of the limiting part is larger than the inner diameter of the mounting hole, so that the limiting part will not extend into the mounting hole.

[0018] In some technical solutions, optionally, the rotating shaft is provided with a tool relief groove, which is located between the knurled part and the guide part.

[0019] During the machining of the guide section and the knurled section of the rotary shaft, a tool relief groove is set between the guide section and the knurled section. The tool relief groove provides a space for the tool to exit, avoiding collision or scratching between the tool and the machined surface at the end of the machining process, thereby ensuring machining accuracy and surface quality and preventing tool damage.

[0020] Incorporating a relief groove at the transition section of the shaft can make the shaft structure more rational and reduce stress concentration caused by abrupt changes in cross-section. Stress concentration can easily lead to fatigue cracks in the shaft during use, reducing its service life. A well-designed relief groove can effectively alleviate this situation and improve the reliability and stability of the shaft.

[0021] In some technical solutions, the mounting hole may optionally include a first inner hole and a second inner hole, the diameter of the second inner hole being larger than the diameter of the first inner hole, the second inner hole being located on the side of the first inner hole away from the limiting part, and the knurled part being embedded in the inner wall of the first inner hole.

[0022] When the shaft and brake rotor are installed together, the knurled part needs to cut the inner wall of the mounting hole, which will reduce the structural strength of the brake rotor. In this solution, the diameter of the second inner hole is larger than that of the first inner hole, which is equivalent to thickening part of the brake rotor in the first inner hole. Even if part of the inner wall of the first inner hole is chipped off, the brake rotor still has sufficient structural strength.

[0023] In some technical solutions, optionally, the braking torque of the motor is T1, and the torque that the knurled part can transmit is T2, where 1.2×T1≤T2≤2×T1.

[0024] If the axial length of the knurled part is too small, the shaft and brake rotor may rotate relative to each other. If the axial length of the knurled part is too large, it may affect the structural strength of the shaft. Therefore, the axial length of the knurled part needs to be limited. Since different motors may have different sizes, simply limiting the axial length of the knurled part may not be suitable for motors of different sizes. In this solution, the size of the knurled part is simply limited by the torque it can transmit. When the braking torque of the motor is T1, the torque that the knurled part can transmit is T2, and the following relationship is satisfied: 1.2×T1≤T2≤2×T1. Within this range, the knurled part can stably transmit torque without being too long.

[0025] Secondly, this application proposes a robot that includes a motor as described in the first aspect.

[0026] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0027] 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:

[0028] Figure 1 shows a partial structural schematic diagram of the motor in an embodiment of this application;

[0029] Figure 2 shows a partial structural schematic diagram of the motor in an embodiment of this application;

[0030] Figure 3 shows a schematic diagram of the structure of the rotating shaft in an embodiment of this application;

[0031] Figure 4 shows a partial structural schematic diagram of the rotating shaft in an embodiment of this application;

[0032] Figure 5 shows a schematic diagram of the brake rotor in an embodiment of this application.

[0033] Figure label:

[0034] 100 Motor, 110 Brake rotor, 111 Mounting hole, 112 Limiting groove, 113 First inner hole, 114 Second inner hole, 120 Rotary shaft, 121 Knurled part, 122 Receiving groove, 123 Guide part, 124 Shaft body, 125 Limiting part, 126 Unloading groove. Embodiments of the present invention

[0035] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0037] The motor and robot provided according to some embodiments of this application are described below with reference to Figures 1 to 5.

[0038] Referring to Figures 1, 2, 3, 4, and 5, in some embodiments of this application, a motor 100 is proposed. The motor 100 includes a brake rotor 110 and a rotating shaft 120. The brake rotor 110 has a mounting hole 111, and the rotating shaft 120 is inserted into the mounting hole 111. Along the direction in which the rotating shaft 120 is mounted to the mounting hole 111 (indicated by the arrow at point A in Figure 2), the rotating shaft 120 is sequentially provided with a knurled portion 121 and a receiving groove 122. The knurled portion 121 and the receiving groove 122 are arranged adjacent to each other. The maximum distance between the axis O of the rotating shaft 120 and the knurled portion 121 is greater than the radius of the mounting hole 111, so that at least a portion of the knurled portion 121 is embedded in the inner wall of the mounting hole 111.

[0039] When assembling the motor 100, the shaft 120 needs to be inserted into the mounting hole 111 of the brake rotor 110. The surface of the shaft 120 is machined with a knurled portion 121. The maximum distance between the axis O of the shaft 120 and the knurled portion 121 is L1, and the radius of the mounting hole 111 is L2. L1 is greater than L2. When installing the shaft 120 and the brake rotor 110, interference will occur between the knurled portion 121 and the brake rotor 110. When the shaft 120 is inserted into the mounting hole 111, the knurled portion 121 will cut the inner wall of the mounting hole 111, so that a part of the inner wall of the mounting hole 111 is removed by the knurled portion 121. The removed part of the structure avoids the knurled portion 121, thereby allowing the shaft 120 to be installed into the mounting hole 111.

[0040] During the cutting process of the knurled part 121 on the inner wall of the mounting hole 111, chips are generated. These chips can accumulate in the receiving groove 122. In this design, the receiving groove 122 is provided on the adjacent side of the knurled part 121. In the direction of installation of the rotating shaft 120 into the mounting hole 111, the knurled part 121 and the receiving groove 122 are arranged sequentially. During the installation of the rotating shaft 120 and the brake rotor 110, the chips cut by the knurled part 121 will fall into the receiving groove 122 in front. By accommodating the chips through the receiving groove 122, the rotating shaft 120 and the brake rotor 110 are prevented from being squeezed by the accumulated chips, thus avoiding deformation of the rotating shaft 120 due to compression. In this design, the receiving groove 122 provides space for the chips, preventing the chips from squeezing the rotating shaft 120, thereby ensuring that the rotating shaft 120 has sufficient precision. After the knurled part 121 cuts the inner wall of the mounting hole 111, a portion of the knurled part 121 is embedded into the inner wall of the mounting hole 111. At this time, the rotating shaft 120 and the brake rotor 110 are fixed in the circumferential direction, and the brake rotor 110 and the rotating shaft 120 can rotate synchronously. No additional parts are needed to realize the torque transmission between the brake rotor 110 and the rotating shaft 120, reducing the mounting parts of the motor 100 and simplifying the installation process of the motor 100.

[0041] Referring to Figures 1, 2, 3, 4 and 5, in some embodiments, optionally, the volume of the knurled portion 121 embedded in the inner wall of the mounting hole 111 is smaller than the volume of the receiving groove 122.

[0042] The volume of the knurled part 121 embedded in the inner wall of the mounting hole 111 is the volume of the removed chips. In this solution, the volume of the knurled part 121 embedded in the inner wall of the mounting hole 111 is limited to the volume of the receiving groove 122. This means that the volume of the removed chips is less than the volume of the receiving groove 122, ensuring that the volume of the receiving groove 122 is sufficient to accommodate the removed chips and avoid the chips from exerting pressure on the rotating shaft 120.

[0043] Referring to Figures 1, 2, 3, 4 and 5, in some embodiments, optionally, the volume of the knurled portion 121 embedded in the inner wall of the mounting hole 111 is V1, and the volume of the receiving groove 122 is V2, where V2 ≥ 1.1 × V1.

[0044] In this design, the volume of the knurled part 121 embedded in the inner wall of the mounting hole 111 is defined as V1, that is, the volume of the removed chips is V1. The volume of the removed chips and the volume of the receiving groove 122 satisfy the following condition: V2 ≥ 1.1 × V1. After the chips are removed and fall into the receiving groove 122, the chips will not be completely stacked in the receiving groove 122, so there will be gaps between the chips. The volume of the receiving groove 122 and the volume of the chips satisfy the above range. Even if there are gaps between the chips, the receiving groove 122 can effectively accommodate the chips and avoid the chips from exerting pressure on the rotating shaft 120.

[0045] Referring to Figures 2, 3, 4 and 5, in some embodiments, optionally, along the axial direction of the rotating shaft 120 (indicated by the arrow at H in Figure 4), the sum of the length of the knurled portion 121 and the length of the receiving groove 122 is less than the length of the brake rotor 110.

[0046] If the receiving groove 122 extends out of the brake rotor 110, the chips will fall to the outside of the brake rotor 110. Also, if the receiving groove 122 is not cleaned properly, the chips in the receiving groove 122 may fall outward as the motor 100 is used, resulting in chips inside the motor 100 and affecting the quality of the motor 100.

[0047] If the length of the knurled part 121 is too long, it will greatly increase the difficulty of installing the shaft 120. Therefore, in this solution, the sum of the lengths of the knurled part 121 and the receiving groove 122 is limited to less than the length of the brake rotor 110. Moreover, after the shaft 120 is installed, the receiving groove 122 will not protrude from the brake rotor 110, which can prevent chips from falling to the outside of the brake rotor 110. In addition, within the above-mentioned length range, the receiving groove 122 is not located at the axial end of the brake rotor 110, thereby avoiding a large overhang area between the axial end of the brake rotor 110 and the shaft 120, and preventing the shaft 120 from deforming.

[0048] Referring to Figures 2, 3, 4, and 5, in some embodiments, optionally, the rotating shaft 120 includes a guide portion 123 and a shaft body 124. The radius of the guide portion 123 is larger than the radius of the shaft body 124. Along the axial direction of the rotating shaft 120, a receiving groove 122 is located between the knurled portion 121 and the guide portion 123. The guide portion 123 is clearance-fitted with the mounting hole 111, and the distance between the guide portion 123 and the inner wall of the mounting hole 111 is W, where 0.005mm ≤ W ≤ 0.05mm.

[0049] A portion of the structure of the rotating shaft 120 serves as a guide portion 123. Along the axial direction of the rotating shaft 120, a receiving groove 122 is located between the knurled portion 121 and the guide portion 123. In the direction in which the rotating shaft 120 is installed into the mounting hole 111, the knurled portion 121, the receiving groove 122, and the guide portion 123 are arranged sequentially. Therefore, during the installation of the rotating shaft 120 and the brake rotor 110, the guide portion 123 extends into the mounting hole 111 before the receiving groove 122. The guide portion 123 has a larger radius than the shaft body 124. The guide portion 123 is spaced and fitted with the inner wall of the mounting hole 111. The guide portion 123 guides the installation process of the rotating shaft 120, ensuring that the knurled portion 121 is pressed into the inner wall of the mounting hole 111 in the correct direction, preventing the rotating shaft 120 from tilting during installation, ensuring the installation accuracy of the rotating shaft 120 and the brake rotor 110, and preventing uneven brake air gap.

[0050] Referring to Figures 2, 3, 4, and 5, in some embodiments, the rotating shaft 120 may optionally include a limiting portion 125, with the limiting portion 125 and the guide portion 123 located on opposite axial sides of the knurled portion 121. The brake rotor 110 is provided with a limiting groove 112, with at least a portion of the limiting portion 125 extending into the limiting groove 112, and the limiting portion 125 abutting against the inner wall of the limiting groove 112 along the axial direction of the rotating shaft 120.

[0051] A limiting part 125 is provided on the rotating shaft 120, and a limiting groove 112 is provided at one axial end of the brake rotor 110. During the process of installing the rotating shaft 120 into the mounting hole 111, when the limiting part 125 abuts against the inner wall of the limiting groove 112 along the axial direction of the rotating shaft 120, it indicates that the rotating shaft 120 has been installed in place. At this time, the limiting groove 112 limits the limiting part 125 to prevent the rotating shaft 120 from continuing to move relative to the brake rotor 110 along the axial direction.

[0052] In this embodiment, the radius of the limiting part 125 is larger than the inner diameter of the mounting hole 111, so that the limiting part 125 will not extend into the mounting hole 111.

[0053] Referring to Figures 2, 3, 4 and 5, in some embodiments, optionally, the rotating shaft 120 is provided with a tool relief groove 126, which is located between the knurled portion 121 and the guide portion 123.

[0054] During the machining process of the guide section 123 and the knurled section 121 by the rotating shaft 120, a tool relief groove 126 is provided between the guide section 123 and the knurled section 121. The tool relief groove 126 can provide a space for the tool to exit, avoiding collision or scratching between the tool and the machined surface at the end of machining, thereby ensuring machining accuracy and surface quality and preventing tool damage.

[0055] The tool relief groove 126 on the transition section of the rotating shaft 120 makes the structure of the rotating shaft 120 more reasonable and reduces stress concentration caused by abrupt changes in cross-section. Stress concentration can easily lead to fatigue cracks in the rotating shaft 120 during use, reducing its service life. The reasonable design of the tool relief groove 126 can effectively alleviate this situation and improve the reliability and stability of the rotating shaft 120.

[0056] Referring to Figures 2, 3, 4 and 5, in some embodiments, the mounting hole 111 may optionally include a first inner hole 113 and a second inner hole 114. The diameter of the second inner hole 114 is larger than the diameter of the first inner hole 113. The second inner hole 114 is located on the side of the first inner hole 113 away from the limiting part 125, and the knurled part 121 is embedded in the inner wall of the first inner hole 113.

[0057] When the rotating shaft 120 and the brake rotor 110 are installed together, the knurled part 121 needs to cut the inner wall of the mounting hole 111, which will reduce the structural strength of the brake rotor 110. In this solution, the diameter of the second inner hole 114 is larger than the diameter of the first inner hole 113, which is equivalent to thickening part of the brake rotor 110 in the first inner hole 113. Even if part of the inner wall of the first inner hole 113 is chipped off, the brake rotor 110 still has sufficient structural strength.

[0058] The mounting hole 111 is divided into at least two sections, namely, a first inner hole 113 and a second inner hole 114, wherein the diameter of the second inner hole 114 is larger than the diameter of the first inner hole 113. During the process of inserting the rotating shaft 120 into the mounting hole 111, the guide part 123 can be clearance-fitted with the first inner hole 113 to guide the rotating shaft 120. As the rotating shaft 120 is installed, when a part of the guide part 123 extends into the second inner hole 114, the knurled part 121 has already embedded in the inner wall of the mounting hole 111. At this time, the guide part 123 does not need to continue to guide the rotating shaft 120. Therefore, it can be limited that when the knurled part 121 is embedded in the inner wall of the mounting hole 111, a part of the guide part 123 extends into the second inner hole 114. Since the diameter of the second inner hole 114 is large, the guide part 123 is not likely to come into contact with the inner wall of the second inner hole 114, thereby reducing the friction force generated by the inner wall of the mounting hole 111 on the guide part 123 and reducing the installation difficulty of the rotating shaft 120.

[0059] In some embodiments, the braking torque of the motor 100 is T1, and the torque that the knurled portion 121 can transmit is T2, where 1.2×T1≤T2≤2×T1.

[0060] If the axial length of the knurled portion 121 is too small, the shaft 120 and the brake rotor 110 may rotate relative to each other. If the axial length of the knurled portion 121 is too large, it may affect the structural strength of the shaft 120. Therefore, the axial length of the knurled portion 121 needs to be limited. Since different motors 100 may have different sizes, simply limiting the axial length of the knurled portion 121 may not be suitable for motors 100 of different sizes. In this solution, the size of the knurled portion 121 is simply limited by the torque that it can transmit. When the braking torque of the motor 100 is T1, the torque that the knurled portion 121 can transmit is T2, and the following relationship is satisfied: 1.2×T1≤T2≤2×T1. Within this range, the knurled portion 121 can stably transmit torque, and the length of the knurled portion 121 will not be too long.

[0061] In the above embodiment, the brake rotor 110 is provided with a mounting hole 111 and a limiting groove 112. The rotating shaft 120 and the brake rotor 110 are knurled together to transmit braking torque. The effective length of the knurled part 121 should be sufficient to transmit sufficient braking torque, and the cavity of the receiving groove 122 should be larger than the chips generated during the installation of the knurled part 121. The knurled fit length of the rotating shaft 120 and the brake rotor 110 cannot extend through the entire axial length of the mounting hole 111. Therefore, the left side of the knurled fit is a closed end. However, when the knurled part 121 is pressed in, the chip removal direction is on the right end. Therefore, sufficient chip storage space can only be provided inside the fit area. This can prevent the brake rotor 110 from being squeezed and deformed too much, which would lead to poor installation accuracy or even breakage. The extension end of the rotating shaft 120 is also provided with a guide end for the installation of the brake rotor 110. The guide part 123 and the mounting hole 111 are clearance fit, and the clearance dimension on one side of the fit is set to 0.005mm to 0.05mm. This ensures that when the brake rotor 110 is pressed into the knurled part 121 of the rotating shaft 120, the pressing direction is correct and it is not tilted, thus ensuring the installation accuracy of the brake rotor 110 and preventing uneven brake air gap.

[0062] This application design incorporates a receiving groove 122 on the rotating shaft 120 to store the chips generated during the knurling and cold pressing of the brake rotor 110, reducing the compressive stress generated during press fitting and ensuring the installation accuracy of the brake rotor 110. The rotating shaft 120 also provides a guide for pressing the brake rotor 110 into position 123, preventing tilted pressing and ensuring the installation accuracy of the brake rotor 110. The brake rotor 110 is fixed without the need for additional set screws or keys, making installation convenient and increasing production efficiency. Furthermore, the knurled part 121 is embedded in the mounting hole 111 of the brake rotor 110, ensuring high reliability and eliminating concerns about slippage that could lead to brake failure.

[0063] The amount of chips generated when the knurled part 121 is pressed in ensures that the cavity space of the receiving groove 122 is more than 1.1 times the volume of the chips.

[0064] In one possible application, the receiving groove 122 can be a knurled relief groove on the rotating shaft 120. The knurled relief groove provides a space for the tool to exit, avoiding collision or scratching between the tool and the machined surface at the end of the machining process, thereby ensuring machining accuracy and surface quality and preventing tool damage. The knurled relief groove 126 can also provide a space for chips.

[0065] In the embodiments of this application, a robot is proposed, which includes a motor as in any of the above embodiments and can achieve the same technical effect, and will not be described again here.

[0066] In this application, the term "multiple" refers to two or more unless otherwise expressly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0067] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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.

[0068] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electric motor, wherein, include: A brake rotor having mounting holes; A rotating shaft is inserted into the mounting hole. Along the direction of the rotating shaft being installed into the mounting hole, the rotating shaft is provided with a knurled part and a receiving groove in sequence. The knurled part and the receiving groove are arranged adjacent to each other. The maximum distance between the axis of the rotating shaft and the knurled part is greater than the radius of the mounting hole, so that at least a portion of the knurled part is embedded in the inner wall of the mounting hole.

2. The motor according to claim 1, wherein, The volume of the knurled part embedded in the inner wall of the mounting hole is smaller than the volume of the receiving groove.

3. The motor according to claim 2, wherein, The volume of the knurled part embedded in the inner wall of the mounting hole is V1, and the volume of the receiving groove is V2, where V2 ≥ 1.1 × V1.

4. The motor according to any one of claims 1 to 3, wherein, Along the axial direction of the rotating shaft, the sum of the length of the knurled portion and the length of the receiving groove is less than the length of the brake rotor.

5. The motor according to any one of claims 1 to 3, wherein, The rotating shaft includes a guide portion and a shaft body. The radius of the guide portion is greater than the radius of the shaft body. Along the axial direction of the rotating shaft, the receiving groove is located between the knurled portion and the guide portion. The guide portion is clearance-fitted with the mounting hole, and the distance between the guide portion and the inner wall of the mounting hole is W, where 0.005mm≤W≤0.05mm.

6. The motor according to claim 5, wherein, The rotating shaft also includes a limiting part, and the limiting part and the guiding part are located on both sides of the knurled part along the axial direction; The brake rotor is provided with a limiting groove, and at least a portion of the limiting part extends into the limiting groove. Along the axial direction of the rotating shaft, the limiting part abuts against the inner wall of the limiting groove.

7. The motor according to claim 5, wherein, The rotating shaft is provided with a tool relief groove, which is located between the knurled part and the guide part.

8. The motor according to claim 6, wherein, The mounting hole includes a first inner hole and a second inner hole. The diameter of the second inner hole is larger than that of the first inner hole. The second inner hole is located on the side of the first inner hole away from the limiting part. The knurled part is embedded in the inner wall of the first inner hole.

9. The motor according to any one of claims 1 to 3, wherein, The braking torque of the motor is T1, and the torque that the knurled part can transmit is T2, where 1.2×T1≤T2≤2×T1.

10. A robot, wherein, include: The motor as described in any one of claims 1 to 9.

Images