Motor system and robot

Abstract

The embodiment of the application provides a motor system and a robot, which comprises a shell, a motor, an input shaft, a harmonic reducer, an output shaft and a rotating support; the input shaft is arranged in the shell and is configured to be driven by the motor to rotate; a wave generator of the harmonic reducer is connected with the input shaft, the wave generator of the harmonic reducer is connected with a flexible gear of the harmonic reducer, and the flexible gear of the harmonic reducer and a rigid gear of the harmonic reducer are matched with each other to transmit torque; a first end of the output shaft is connected with the harmonic reducer, so that the harmonic reducer can drive the output shaft to rotate, the output shaft is a hollow structure and is used for wiring, and the output shaft is arranged in proximity to the input shaft at intervals; the rotating support is arranged at a second end of the output shaft and is used for rotatingly supporting the second end of the output shaft, and the first end of the output shaft and the second end of the output shaft are opposite ends of the output shaft. The application can reduce end jumping of the output shaft.

Description

Technical Field

[0001] This application relates to the field of joint technology, and more particularly to a motor system and a robot. Background Technology

[0002] In transmission systems such as robot joints and precision rotary actuators, the end runout (axial and radial runout) of the output shaft is one of the key factors affecting the stability of encoder signals and the overall control accuracy. To suppress output shaft end runout, related technologies typically add a support bearing between the input and output shafts. The aim is to reduce the runout of the encoder code disk through the radial and axial constraints of the bearing, thereby improving the stability of angle feedback.

[0003] However, the aforementioned technologies have the following main drawbacks: arranging a support bearing between the input and output shafts does not effectively improve the end runout phenomenon of the output shaft. Utility Model Content

[0004] This application provides a motor system and robot designed to improve the problem of output shaft end runout.

[0005] On one hand, this application provides a motor system, including: a housing; a motor; an input shaft disposed within the housing and configured to be driven to rotate by the motor; a harmonic reducer, wherein a wave generator of the harmonic reducer is connected to the input shaft, the wave generator of the harmonic reducer is connected to a flexible wheel of the harmonic reducer, the flexible wheel of the harmonic reducer and a rigid wheel of the harmonic reducer cooperate to transmit torque; an output shaft, wherein a first end of the output shaft is connected to the harmonic reducer so that the harmonic reducer can drive the output shaft to rotate, the output shaft having a hollow structure for wiring, and the output shaft and the input shaft being disposed close to each other at a distance; and

[0006] A rotating support is disposed at the second end of the output shaft for rotatably supporting the second end of the output shaft, wherein the first end and the second end of the output shaft are opposite ends of the output shaft.

[0007] Optionally, the input shaft and the output shaft are coaxially arranged, and the distance between the input shaft and the output shaft in the radial direction is less than the thickness of the rotating support in the radial direction.

[0008] Optionally, the interval distance is 0.25mm to 10mm.

[0009] Optionally, the rotating support includes a bearing, the outer ring of the rotating support is connected to the housing, and the inner ring of the rotating support is connected to the output shaft.

[0010] Optionally, the rotating support includes a bushing, the outer ring of which is connected to the housing, and the inner ring of which is connected to the output shaft.

[0011] Optionally, the rotating support includes a plurality of balls disposed between the output shaft and the housing, wherein at least one of the output shaft and the housing is provided with an annular groove, and the balls are disposed within the annular groove.

[0012] Optionally, the housing is provided with a through hole, and a first limiting ring is provided at one end of the through hole to block one end of the outer ring of the rotating support member;

[0013] A second limiting ring is provided on the output shaft to stop the other end of the inner ring of the rotating support. The second limiting ring and the first limiting ring are respectively located on both sides of the axial direction of the rotating support.

[0014] Optionally, it also includes a circuit board, which is fixed to the housing near the rotating support.

[0015] Optionally, it also includes an encoding component, which includes an input code disk and an output code disk. The input code disk is fixed to the end of the input shaft away from the harmonic reducer, and the output code disk is fixed to the end of the output shaft away from the harmonic reducer. The input code disk and the output code disk are arranged axially spaced apart.

[0016] On the other hand, this application also provides a robot including the aforementioned motor system.

[0017] This application provides rotational support to the second end of the output shaft via a rotating support member. When the output shaft rotates, its second end is stably constrained, effectively suppressing end runout of the output shaft. Attached Figure Description

[0018] Figure 1 This is an overall appearance drawing of a motor system provided in one embodiment of this application;

[0019] Figure 2 This is a half-sectional view of a motor system provided in an embodiment of this application;

[0020] Figure 3 yes Figure 2 Enlarged view of part A.

[0021] Explanation of reference numerals in the attached figures:

[0022] 110. Housing; 111. Motor housing; 112. Tail cover; 113. End cover; 120. Motor; 121. Motor stator; 122. Motor rotor; 130. Input shaft; 140. Output shaft; 141. Shaft body; 142. Output code disk bracket; 143. Flexible wheel fixing washer; 150. Harmonic reducer; 151. Wave generator; 152. Flexible wheel; 153. Rigid wheel; 154. Rigid wheel fixing shell; 160. Rotating support; 170. Brake; 180. Support bearing; 190. Torque sensor; 200. Cross roller bearing; 210. Circuit board; 220. Encoding assembly; 221. Input code disk bracket; 222. Input code disk; 223. Output code disk; 301. First limit ring; 302. Second limit ring. Detailed Implementation

[0023] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0024] Reference Figures 1 to 3 This application provides a motor system including a housing 110, a motor 120, an input shaft 130, an output shaft 140, a harmonic reducer 150, and a rotating support 160. The input shaft 130 is disposed within the housing 110 and configured to be driven to rotate by the motor 120. The harmonic reducer 150 includes a wave generator 151, a flexible wheel 152, a rigid wheel 153, and a rigid wheel mounting housing 154. The wave generator 151 of the harmonic reducer 150 is connected to the input shaft 130. The wave generator 151 of the harmonic reducer 150 is also connected to the flexible wheel 152 of the harmonic reducer 150. The flexible wheel 152 and the rigid wheel 153 of the harmonic reducer 150 cooperate to transmit torque. The first end of the output shaft 140 is connected to the harmonic reducer 150 so that the harmonic reducer 150 can drive the output shaft 140 to rotate. The output shaft 140 can be a hollow structure and can be used for wiring. The output shaft 140 and the input shaft 130 can be arranged close to each other. The rotating support 160 can be arranged at the second end of the output shaft 140 and can be used to rotatably support the second end of the output shaft 140. The first end and the second end of the output shaft 140 can be opposite ends of the output shaft 140.

[0025] Specifically, refer to Figure 1 and Figure 2The housing 110 comprises a motor housing 111, a tail cover 112, and an end cover 113. In the figure, the tail cover 112 can be located on the right side of the motor housing 111 and can be fixed to the motor housing 111 with bolts. The end cover 113 can be located on the left side of the motor housing 111. The motor 120 can be housed within the housing 110. The motor 120 includes a motor stator 121 and a motor rotor 122. The motor stator 121 can be press-fitted into the motor housing 111. The motor system also includes a brake 170. The stator of the brake 170 can be partially press-fitted into the motor housing 111 and secured with screws. The rotor portion of the brake 170 can be bolted to the input shaft 130, enabling it to lock the input shaft 130 when power is off. The right side of the input shaft 130 is bolted to the motor rotor 122, allowing the motor rotor 122 to drive the input shaft 130 to rotate. The input shaft 130 can also be supported by two support bearings 180: the outer ring of the support bearing 180 on the right side of the figure can be pressed into the motor housing 111 by interference fit, and the outer ring of the support bearing 180 on the left side of the figure can be press-fitted into the left end cover 113. The end cover 113 can be bolted to the motor housing 111, thereby ensuring that the input shaft 130 can rotate smoothly. The left end face of the input shaft 130 is connected to the wave generator 151 of the harmonic reducer 150, and the wave generator 151 can be fixed to the left end face of the input shaft 130 by bolts.

[0026] A rotating support 160 is disposed at the second end of the output shaft 140 (the end away from the harmonic reducer 150) to rotatably support the second end of the output shaft 140. The rotating support 160 can be a bearing. The outer ring of the rotating support 160 can be installed in the tail cover 112 by interference fit. The inner ring of the rotating support 160 can be connected to the second end of the output shaft 140 by sliding fit. The inner ring of the rotating support 160 can abut against the output shaft 140, thereby effectively restraining the end runout of the output shaft 140 during operation.

[0027] In some embodiments, the output shaft 140 includes a shaft body 141, an output encoder bracket 142, and a flexible wheel fixing washer 143. The output encoder bracket 142 and the flexible wheel fixing washer 143 are disposed at both ends of the shaft body 141. The flexible wheel fixing washer 143 may be located at the left end of the shaft body 141, forming a first end. The shaft body 141 can be connected to the flexible wheel 152 through the flexible wheel fixing washer 143. Specifically, the flexible wheel fixing washer 143 may be provided with a groove, and the first end of the output shaft 140 may be press-fitted and glued into the groove on the flexible wheel fixing washer 143. In other embodiments, the flexible wheel fixing washer may also be fixedly connected to the first end of the output shaft in other ways. The output encoder bracket 142 is located at the right end of the shaft body 141, and the output encoder bracket 142 forms a second end of the output shaft 140. The rotating support 160 may be disposed on the output encoder bracket 142.

[0028] In other embodiments, the rotating support can be installed in other external devices, but it is necessary to ensure that the rotating support can stably support the second end of the output shaft. For example, the rotating support can be installed on the ground by a bracket. In this case, it is necessary to ensure that the coaxiality of the rotating support 160 and the output shaft is high.

[0029] The motor system also includes a torque sensor 190 and a crossed roller bearing 200. The flexible wheel 152 and the torque sensor 190 can be connected by bolts. The torque sensor 190 and the inner ring of the crossed roller bearing 200 can be connected by bolts. The outer ring of the crossed roller bearing 200 and the rigid wheel fixing housing 154 can be connected by bolts. The rigid wheel 153 and the rigid wheel fixing housing 154 can be connected by bolts.

[0030] When the motor stator 121 is energized, the motor rotor 122 rotates, causing the input shaft 130, which is bolted to it, to rotate synchronously. The input shaft 130 drives the wave generator 151 on its left end face to rotate, forcing the flexible wheel 152 to undergo periodic elastic deformation and mesh with the rigid wheel 153. Since the rigid wheel 153 is fixed to the rigid wheel fixing housing 154, the flexible wheel 152 can achieve low-speed, high-torque output under the drive of the wave generator 151. The flexible wheel 152 transmits torque to the first end of the output shaft 140, driving the output shaft 140 to rotate.

[0031] The second end of the output shaft 140 can be provided with rotational support by the rotating support 160. When the output shaft 140 rotates, its second end is stably constrained, effectively suppressing end runout caused by the cantilever structure. Simultaneously, the input code disk 222 on the right side of the input shaft 130 rotates with the input shaft 130, and the output code disk 223 at the second end of the output shaft 140 can rotate smoothly with the output shaft 140. The encoder on the control board (i.e., circuit board 210) can read the angles of both in real time. Because the runout of the output shaft 140 is suppressed, the rotation trajectory of the output code disk 223 is stable, and the accuracy of the angle signal acquired by the encoder is significantly improved.

[0032] In this application, the output shaft 140 can be a hollow structure to facilitate wiring within its cavity. Since the rotating support 160 is located at the second end of the output shaft 140 and not between the input shaft 130 and the output shaft 140, the output shaft 140 can be positioned closer to the input shaft 130 in space. This allows for an increase in the diameter of the output shaft 140's cavity, providing ample space for wiring within the robot joint and supporting a wider and thicker cable layout. It is understood that the input shaft 130 and the output shaft 140 can be in contact without any contact, or indirectly connected by a small bearing. As long as the input shaft 130 is positioned close to the output shaft 140, it is possible to enlarge the central cavity of the output shaft 140.

[0033] Reference Figure 2 and Figure 3 In some optional embodiments, the input shaft 130 and the output shaft 140 can be coaxially arranged, and the radial distance between the input shaft 130 and the output shaft 140 can be less than the radial thickness of the rotating support 160. In this embodiment, the input shaft 130 and the output shaft 140 can be coaxially fitted, and the central axis directions of the input shaft 130 and the output shaft 140 can coincide (the central axis direction is parallel to the...). Figure 2 (In the left-right direction), the radial directions of the input shaft 130 and the output shaft 140 can be the same. The rotating support 160 can be a bearing, and the thickness of the rotating support 160 in the radial direction can be the distance between the inner and outer ring surfaces of the bearing. By ensuring that the distance between the input shaft 130 and the output shaft 140 is less than the radial thickness of the rotating support 160, the rotating support 160 will not be embedded between the input shaft 130 and the output shaft 140, thereby ensuring the supporting effect of the rotating support 160.

[0034] In some alternative embodiments, the input shaft and output shaft are not coaxial. For example, the input shaft 130 and output shaft 140 can be parallel shafts, with their axes parallel to each other and radially spaced by a certain distance. In this case, a first transmission wheel can be provided on the flexible wheel 152 of the harmonic reducer 150 (or a transmission component fixedly connected to the flexible wheel 152), and a second transmission wheel can be provided at the first end of the output shaft 140. The first and second transmission wheels mesh with each other or are connected by a synchronous belt drive, so that the torque output by the harmonic reducer 150 can be transmitted to the output shaft 140. The output shaft 140 remains a hollow structure for wiring; the rotating support 160 is still provided at the second end of the output shaft 140 for rotatably supporting the second end of the output shaft 140.

[0035] In this embodiment, since the output shaft 140 and the input shaft 130 are not coaxial, there is no need to install bearings or support structures between them. The first end of the output shaft 140 is connected to the harmonic reducer 150 only through a transmission wheel, thus allowing for greater radial freedom of the output shaft 140. Simultaneously, the second end of the output shaft 140 is independently supported by a rotating support 160, effectively suppressing end runout and ensuring the rotational stability of the output encoder 223. The diameter of the hollow output shaft 140 can be further increased according to wiring requirements, providing more ample routing channels for cables inside the robot joints.

[0036] In some optional embodiments, the spacing can be from 0.25mm to 10mm. The spacing in this embodiment can cover the clearance requirements of common robot joint modules. The lower limit of 0.25mm ensures that the input shaft 130 and the output shaft 140 will not come into contact or rub against each other during high-speed rotation, while the upper limit of 10mm balances compactness and assembly tolerance.

[0037] In some alternative embodiments, the rotating support 160 includes a bearing. The outer ring of the rotating support 160 can be fixedly connected to the housing 110 to ensure support strength, and the inner ring of the rotating support 160 can be connected to the output shaft 140. The rotating support 160 configured in this way has the advantages of high load-bearing capacity, low rotational resistance, and long service life.

[0038] In some optional embodiments, the rotary support 160 includes a bushing. The outer ring of the rotary support 160 can be connected to the housing 110, and the inner ring of the rotary support 160 can be connected to the output shaft 140. The bushing, as a sliding bearing, has the advantages of simple structure, small radial dimension, and low cost. Using a bushing in joint modules with light loads and low rotational speeds can further reduce the module volume while ensuring support effectiveness, making it particularly suitable for microrobot joints.

[0039] In some optional embodiments, the rotating support 160 includes a plurality of balls disposed between the output shaft 140 and the housing 110. At least one of the output shaft 140 and the housing 110 may be provided with an annular groove, within which the balls may be disposed. The structure in this embodiment essentially constitutes a set of ball bearings, eliminating the need for separate outer and inner rings, further reducing the radial space occupied. The annular groove guides and retains the balls, creating a point-contact rolling support between the output shaft 140 and the housing 110, combining low friction and small size.

[0040] Reference Figure 2 and Figure 3In some optional embodiments, the housing 110 is provided with a through hole, and a first limiting ring 301 is provided at one end of the through hole to stop one end of the outer ring of the rotating support 160. A second limiting ring 302 is provided on the output shaft 140 to stop the other end of the inner ring of the rotating support 160. The second limiting ring 302 and the first limiting ring 301 can be located on opposite axial sides of the rotating support 160, respectively. In this embodiment, the rotating support 160 is reliably positioned between the housing 110 and the output shaft 140 by the bidirectional axial stopping of the first limiting ring 301 and the second limiting ring 302, preventing axial movement caused by vibration or thermal expansion. This limiting structure eliminates the need for additional snap rings or pressure plates, simplifying the assembly process.

[0041] In some optional embodiments, the motor system further includes a circuit board 210, which can be fixed to the housing 110 near the rotating support 160. In this embodiment, the circuit board 210 is provided with a clearance hole, through which the output shaft 140 passes. The inner wall of the clearance hole and the circumferential surface of the output shaft 140 can be spaced apart. The circuit board 210 can be fixed to the motor housing 111 with bolts. Arranging the circuit board 210 (typically an encoder read control board) close to the rotating support 160 can shorten the axial distance between the output code disk 223 and the read head on the circuit board 210, reduce the signal transmission path, and decrease electromagnetic interference. Meanwhile, the stable constraint of the rotating support 160 on the output shaft 140 makes the rotation plane height of the output code disk 223 fixed at the end of the output shaft 140 stable, and the noise of the angle signal read by the circuit board 210 is lower, which is conducive to achieving high-precision closed-loop control. At the same time, since the rotating support 160 reduces the end runout of the output shaft 140, it effectively reduces the problem of the end runout of the output shaft 140 scraping or hitting the circuit board 210.

[0042] In some optional embodiments, the motor system further includes an encoding assembly 220, which includes an input code disk bracket 221, an input code disk 222, and an output code disk 223. The input code disk 222 can be adhesively mounted on the input code disk bracket 221 and bolted to the end of the input shaft 130 away from the harmonic reducer 150 (right end face). The output code disk 223 can be adhesively mounted on the output code disk bracket 142 and press-fitted to the end of the output shaft 140 away from the harmonic reducer 150 (right end face). The input code disk 222 and the output code disk 223 can be arranged axially spaced. Because the end of the output shaft 140 is effectively constrained by the rotating support 160, the runout of the output code disk 223 is significantly reduced, resulting in a substantial improvement in the accuracy of the output angle measurement. Meanwhile, the input encoder 222 directly reflects the actual rotation angle of the motor rotor 122, and the output encoder 223 reflects the actual rotation angle of the joint output end. The comparison between the two can calculate the transmission error of the harmonic reducer 150 in real time, providing accurate feedback data for servo control.

[0043] On the other hand, this application may also provide a robot including the motor system described in the above embodiments.

[0044] In this application, "multiple" refers to two or more.

[0045] In this application, unless otherwise expressly defined, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] The terms “first,” “second,” “third,” “fourth,” etc., in this application (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0047] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0048] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, if the method includes steps A and B, it means that the method may include steps A and B performed sequentially, or steps B and A performed sequentially. For example, if the method may also include step C, it means that step C may be added to the method in any order. For example, the method may include steps A, B, and C, or steps A, C, and B, or steps C, A, and B, etc.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A motor system, characterized in that, include: case; Electric motor; An input shaft, disposed within the housing, is configured to be driven to rotate by the motor; A harmonic reducer, wherein the wave generator of the harmonic reducer is connected to the input shaft, the wave generator of the harmonic reducer is connected to the flexible wheel of the harmonic reducer, and the flexible wheel of the harmonic reducer cooperates with the rigid wheel of the harmonic reducer to transmit torque; An output shaft, the first end of which is connected to the harmonic reducer so that the harmonic reducer can drive the output shaft to rotate; the output shaft has a hollow structure for wiring; and the output shaft is positioned close to and spaced apart from the input shaft. A rotating support is disposed at the second end of the output shaft for rotatably supporting the second end of the output shaft, wherein the first end and the second end of the output shaft are opposite ends of the output shaft.

2. The motor system according to claim 1, characterized in that, The input shaft and the output shaft are coaxially arranged, and the distance between the input shaft and the output shaft in the radial direction is less than the thickness of the rotating support in the radial direction.

3. The motor system according to claim 2, characterized in that, The interval is 0.25mm to 10mm.

4. The motor system according to claim 1, characterized in that, The rotating support includes a bearing, the outer ring of the rotating support is connected to the housing, and the inner ring of the rotating support is connected to the output shaft.

5. The motor system according to claim 1, characterized in that, The rotating support includes a bushing, the outer ring of which is connected to the housing, and the inner ring of which is connected to the output shaft.

6. The motor system according to claim 1, characterized in that, The rotating support includes a plurality of balls disposed between the output shaft and the housing, at least one of the output shaft and the housing having an annular groove, and the balls being disposed within the annular groove.

7. The motor system according to claim 1, characterized in that, The housing is provided with a through hole, and a first limiting ring is provided at one end of the through hole to block one end of the outer ring of the rotating support member; A second limiting ring is provided on the output shaft to stop the other end of the inner ring of the rotating support. The second limiting ring and the first limiting ring are respectively located on both sides of the axial direction of the rotating support.

8. The motor system according to claim 1, characterized in that, It also includes a circuit board, which is fixed to the housing near the rotating support.

9. The motor system according to claim 1, characterized in that, It also includes an encoding component, which includes an input code disk and an output code disk. The input code disk is fixed to the end of the input shaft away from the harmonic reducer, and the output code disk is fixed to the end of the output shaft away from the harmonic reducer. The input code disk and the output code disk are arranged axially at a distance.

10. A robot, characterized in that, The motor system included in any one of claims 1 to 9.

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