Robotic joint
By optimizing the design of cross roller bearings and hollow bearings, and combining them with the clever arrangement of the braking device, the problem of insufficient internal space utilization in robot joints was solved, resulting in a compact and efficient robot joint structure that improves the performance and appearance of the robotic arm.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 北京敏锐达致机器人科技有限责任公司
- Filing Date
- 2025-04-23
- Publication Date
- 2026-06-02
AI Technical Summary
The internal space of existing robot joints cannot be fully utilized, resulting in larger axial dimensions and increased weight, which affects the function and performance of the robotic arm.
The design of the harmonic reducer is optimized by using crossed roller bearings, combined with the clever arrangement of hollow shaft, support bearings and braking device, which reduces the number of parts and internal space occupation, and optimizes space utilization.
It achieves a compact design for robot joints, high rigidity, high output torque density, and lightweight design, reducing axial dimensions and weight, and improving the performance and appearance of the robotic arm.
Smart Images
Figure CN224310658U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a robotic joint. Background Technology
[0002] Joints are crucial components of robotic arms. A common joint structure, from bottom to top, consists of: a harmonic reducer, a frameless motor, a high-speed magnetic encoder and reader, a brake, and a low-speed magnetic encoder and reader. This layered approach prevents full utilization of the joint's internal space, resulting in a larger axial dimension and increased weight, directly impacting the robotic arm's functionality, performance, and appearance.
[0003] In another implementation, although the harmonic reducer adopts a three-component harmonic design to change the axial dimension of the harmonic installation, its cross roller bearing still adopts a conventional design. The steel wheel of the harmonic reducer is connected to the outer ring of the cross roller bearing, and the output end and flexible wheel are connected to the inner ring of the cross roller bearing, which is not conducive to reducing the diameter and weight of the reducer. Utility Model Content
[0004] To address one of the aforementioned technical problems, this disclosure provides a robot joint.
[0005] According to one aspect of this disclosure, a robot joint is provided, comprising:
[0006] A drive unit for providing driving force;
[0007] A harmonic reducer, comprising a wave generator, a flexible wheel, and a rigid wheel; the drive device is connected to the wave generator to transmit driving force to the harmonic reducer;
[0008] The output flange is provided with a rigid wheel of the harmonic reducer connected to the output flange via a first bearing; the flexible wheel of the harmonic reducer is fixedly connected to the output flange; the first bearing is a crossed roller bearing, the output flange is fixed to the outer ring of the first bearing, and the rigid wheel of the harmonic reducer is fixed to the inner ring of the first bearing;
[0009] A hollow shaft is provided, one end of which is connected to the output flange, and the output flange and the hollow shaft have the same axis of rotation and rotate synchronously; the other end of the hollow shaft passes through the harmonic reducer, and a first support bearing is provided between the wave generator and the hollow shaft.
[0010] According to at least one embodiment of the robot joint of the present disclosure, the wave generator has a central hole, the hollow shaft passes through the central hole of the wave generator, the inner ring of the first support bearing is sleeved on the hollow shaft, and the outer ring of the first support bearing is disposed in the central hole of the wave generator.
[0011] A robot joint according to at least one embodiment of the present disclosure further includes:
[0012] A bearing housing is rotatably mounted on the wave generator via a second support bearing, wherein the bearing housing is fixedly connected to the rigid wheel of the harmonic reducer.
[0013] According to at least one embodiment of the robot joint of the present disclosure, the wave generator of the harmonic reducer includes a shoulder, and one end of the inner ring of the second support bearing is positioned by the shoulder of the wave generator.
[0014] According to at least one embodiment of the robot joint of the present disclosure, the other end of the inner ring of the second support bearing is positioned by a baffle fixed to the wave generator.
[0015] According to at least one embodiment of the robot joint of the present disclosure, the bearing housing includes a stepped portion for limiting the position of one end of the outer ring of the second support bearing.
[0016] According to at least one embodiment of the robot joint of the present disclosure, a limiting member is fixed on the bearing seat, the limiting member being used to limit the position of the other end of the outer ring of the second support bearing.
[0017] According to at least one embodiment of the robot joint of the present disclosure, along the axial direction of the hollow shaft, at least a portion of the projection of the second support bearing on the axis of the hollow shaft coincides with at least a portion of the projection of the drive device on the axis of the hollow shaft.
[0018] According to at least one embodiment of the robot joint of the present disclosure, the drive device includes a rotor, the rotor being fixedly connected to the wave generator.
[0019] A robot joint according to at least one embodiment of the present disclosure further includes a braking device for braking the rotor.
[0020] According to at least one embodiment of the robot joint of the present disclosure, the rotor is formed with a concave structure, and at least a portion of the braking device is located within the concave structure of the rotor.
[0021] The robot joint according to at least one embodiment of the present disclosure further includes a high-speed side encoder assembly, the high-speed side encoder assembly including a high-speed side encoder code disk and a high-speed side encoder reading head, the high-speed side encoder code disk being fixedly connected to the rotor; the high-speed side encoder reading head is used to read the high-speed side encoder code disk information and obtain the motion state of the rotor.
[0022] The robot joint according to at least one embodiment of the present disclosure further includes a low-speed side encoder assembly, the low-speed side encoder assembly including a low-speed side encoder code disk and a low-speed side encoder reading head, the low-speed side encoder code disk being fixedly connected to the hollow shaft, and the low-speed side encoder reading head being used to read the low-speed side encoder code disk information and obtain the motion state of the output flange.
[0023] According to at least one embodiment of the robot joint of this disclosure, the high-speed side encoder disk is fixedly connected to the rotor via a first bracket, the first bracket being rotatably disposed on the hollow shaft via a second bearing.
[0024] According to at least one embodiment of the robot joint of the present disclosure, the braking device is located between the first support and the drive device.
[0025] According to at least one embodiment of the robot joint of the present disclosure, the first support includes a first recessed region and a second recessed region, the high-speed side encoder disk is located in the first recessed region, and the low-speed side encoder disk is located in the second recessed region.
[0026] According to at least one embodiment of the robot joint of the present disclosure, the high-speed side encoder disk and the low-speed side encoder disk are positioned at the same or substantially the same axial position in the hollow shaft.
[0027] According to at least one embodiment of the robot joint of this disclosure, the high-speed side encoder disk is further away from the hollow shaft than the low-speed side encoder disk.
[0028] According to at least one embodiment of the robot joint of the present disclosure, the low-speed side encoder disk is disposed on the hollow shaft by a second bracket, wherein at least a portion of the second bracket is located within the second recessed area. Attached Figure Description
[0029] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.
[0030] Figure 1 This is a schematic diagram of the structure of a robot joint according to one embodiment of the present disclosure.
[0031] Figure 2 yes Figure 1 Enlarged schematic diagram of part A.
[0032] The specific labels in the attached figures are as follows:
[0033] 100 robot joints
[0034] 110 Drive Unit
[0035] 111 Stator
[0036] 112 Rotor
[0037] 120 harmonic reducer
[0038] 121 Wave Generator
[0039] 122 Flexible Wheel
[0040] 123 Steel Wheel
[0041] 130 Output Flange
[0042] 140 hollow shaft
[0043] 150 Casing Section
[0044] 160 First Bearing
[0045] 161 Crossed Roller Bearing Inner Ring
[0046] 162 Crossed Roller Bearing Outer Ring
[0047] 163 Sealing Ring
[0048] 170 First Support Bearing
[0049] 180 inner circlip
[0050] 190 bearing housing
[0051] 200 Second Support Bearing
[0052] 210 baffle
[0053] 220 Limiting component
[0054] 230 Braking device
[0055] 240 High-speed side encoder assembly
[0056] 241 High-speed side encoder code disk
[0057] 242 High-speed side encoder reading head
[0058] 250 Low-speed side encoder assembly
[0059] 251 Low-speed side encoder code disk
[0060] 252 Low-speed side encoder reading head
[0061] 260 Second Bearing
[0062] 270 First support
[0063] 280 Second support. Detailed Implementation
[0064] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.
[0065] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.
[0066] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.
[0067] The use of crosshairs and / or shading in the accompanying drawings is generally used to clarify the boundaries between adjacent components. Thus, unless otherwise stated, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for the specific material, material properties, dimensions, proportions, commonalities between the illustrated components, or any other characteristics, properties, etc., of the components. Furthermore, in the accompanying drawings, the dimensions and relative dimensions of components may be exaggerated for clarity and / or descriptive purposes. When exemplary embodiments can be implemented differently, a specific process sequence may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of their description. Furthermore, the same reference numerals denote the same components.
[0068] When a component is referred to as being "on" or "above" another component, "connected to," or "joined to" another component, the component may be directly on, directly connected to, or directly joined to the other component, or there may be intermediate components. However, when a component is referred to as being "directly on" another component, "directly connected to," or "directly joined to" another component, there are no intermediate components. Therefore, the term "connection" can refer to a physical connection, an electrical connection, etc., and may or may not have intermediate components.
[0069] For descriptive purposes, this disclosure may use spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side (e.g., in a “sidewall”)” to describe the relationship between one component and another component as shown in the accompanying drawings. In addition to the orientations depicted in the drawings, the spatial relative terms are also intended to encompass different orientations of the device during use, operation, and / or manufacture. For example, if the device in the drawings is flipped, a component described as “below” or “under” another component or feature would subsequently be positioned “above” said other component or feature. Thus, the exemplary term “below” can encompass both “above” and “below” orientations. Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or in other orientations), thus interpreting the spatial relative descriptive terms used herein accordingly.
[0070] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “the” are intended to include the plural forms as well. Furthermore, when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, parts, components, and / or groups thereof, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, parts, components, and / or groups thereof. It should also be noted that, as used herein, the terms “substantially,” “about,” and other similar terms are used as approximate terms rather than as terms of degree, thus explaining the inherent biases in measurements, calculated values, and / or provided values that would be recognized by one of ordinary skill in the art.
[0071] like Figure 1 As shown, the robot joint 100 of this disclosure may include a drive unit 110, a harmonic reducer 120, an output flange 130, and a hollow shaft 140, etc. This constitutes a high-performance robot joint that is compact, high-rigidity, high-output torque density, lightweight, and low-cost.
[0072] The drive unit 110 is used to provide driving force. In this disclosure, the drive unit 110 includes a stator 111 and a rotor 112. The stator 111 is disposed in the housing portion 150, and the rotor 112 is connected to the wave generator 121 of the harmonic reducer 120. Thus, the drive unit 110 can drive the wave generator 121 to rotate. In this disclosure, in Figure 1In the implementation shown, the rotor 112 is directly connected to the wave generator 121, thereby reducing the number of parts in the robot joint 100 and making the robot joint 100 easier to assemble. Alternatively, the rotor 112 of this disclosure can also be connected to the wave generator 121 via a drive shaft or other components.
[0073] The harmonic reducer 120 includes a wave generator 121, a flexible wheel 122, and a rigid wheel 123. A drive unit 110 is connected to the wave generator 121 to transmit driving force to the harmonic reducer 120. In this disclosure, the driving force is output to the outside through the flexible wheel 122 of the harmonic reducer 120. For example, the driving force can be output directly through the flexible wheel 122, or it can be output through the output flange 130 mounted on the flexible wheel 122.
[0074] In this disclosure, the rigid wheel 123 of the harmonic reducer 120 is connected to the output flange 130 via a first bearing 160; the flexible wheel 122 of the harmonic reducer 120 is fixedly connected to the output flange 130. Preferably, the first bearing 160 can be a crossed roller bearing.
[0075] Specifically, the first bearing 160 may include a crossed roller bearing inner ring 161 (i.e., the inner ring of the first bearing 160), a crossed roller bearing outer ring 162 (i.e., the outer ring of the first bearing 160), and crossed rollers located between the crossed roller bearing inner ring 161 and the crossed roller bearing outer ring 162. Furthermore, a sealing ring 163 is provided between the crossed roller bearing inner ring 161 and the crossed roller bearing outer ring 162 to prevent dust from entering the crossed roller bearing, thereby improving its lifespan. The principle of this crossed roller bearing is already known in the art; therefore, it will not be described in detail here.
[0076] Therefore, this disclosure, through the optimized design of the crossed roller bearing, can effectively reduce the outer diameter of the rigid wheel and reduce weight; moreover, the robot joint of this disclosure can make full use of the internal space of the crossed roller bearing and ensure sufficient torque transmission capacity.
[0077] In this disclosure, the rigid wheel 123 of the harmonic reducer 120 is fixed to the inner ring 161 of the crossed roller bearing, and the output flange 130 is fixed to the outer ring 162 of the crossed roller bearing. Although not illustrated in this application, those skilled in the art should understand that the rigid wheel 123 of the harmonic reducer 120 can also be fixed to the outer ring of the crossed roller bearing, in which case the output flange 130 can be fixed to the inner ring 161 of the crossed roller bearing.
[0078] In other words, this disclosure does not limit the specific connection method of the rigid wheel 123, the first bearing 160 and the output flange 130 of the harmonic reducer 120. The connection method between these three components is only required to ensure that the rigid wheel 123 and the output flange 130 of the harmonic reducer 120 can rotate freely.
[0079] One end of the hollow shaft 140 is connected to the output flange 130, and the output flange 130 and the hollow shaft 140 have the same axis of rotation and rotate synchronously. In a preferred embodiment, the hollow shaft 140, the output flange 130 and the flexible wheel 122 of the harmonic reducer 120 can be fixed together by screws.
[0080] The other end of the hollow shaft 140 passes through the harmonic reducer 120. Specifically, the hollow shaft 140 of this disclosure can pass through the entire robot joint 100. Moreover, a first support bearing 170 is provided between the wave generator 121 and the hollow shaft 140.
[0081] In one embodiment, the wave generator 121 has a central hole, the hollow shaft 140 passes through the central hole of the wave generator 121, the inner ring of the first support bearing 170 is sleeved on the hollow shaft 140, and the outer ring of the first support bearing 170 is disposed in the central hole of the wave generator 121.
[0082] More preferably, such as Figure 1 As shown, the first support bearing 170 is located inside the flexible wheel 122 of the harmonic reducer 120, which enables the robot joint of this disclosure to have a smaller axial dimension.
[0083] In this disclosure, an annular groove is formed on the side wall of the central hole of the wave generator 121. An inner retaining spring 180 can be disposed in the annular groove. The central hole of the wave generator 121 is formed into a stepped hole. As a result, one end of the outer ring of the first support bearing 170 is restricted in position by the stepped portion of the stepped hole, and the other end of the outer ring of the first support bearing 170 is restricted in position by the inner retaining spring 180. In addition, the inner ring of the first support bearing 170 is not restricted in position. In other words, the inner ring of the first support bearing 170 can slide slightly relative to the hollow shaft 140. Therefore, when there are tolerances in the components of the robot joint, the dimensional chain requirements of each component can be met by the movement of the first support bearing 170 along the axial direction of the hollow shaft 140.
[0084] The robot joint 100 disclosed herein may further include a bearing housing 190, which is rotatably mounted on the wave generator 121 via a second support bearing 200. The bearing housing 190 is fixedly connected to the rigid wheel 123 of the harmonic reducer 120. Additionally, the bearing housing 190 is also fixedly connected to the aforementioned housing portion 150.
[0085] The wave generator 121 of the harmonic reducer 120 includes a shoulder, and one end of the inner ring of the second support bearing 200 is positioned by the shoulder of the wave generator 121; the other end of the inner ring of the second support bearing 200 is positioned by a baffle 210 fixed to the wave generator 121.
[0086] In addition, the bearing housing 190 includes a stepped portion for limiting the position of one end of the outer ring of the second support bearing 200; a limiting member 220 is fixed on the bearing housing 190 for limiting the position of the other end of the outer ring of the second support bearing 200; that is, the position of the second support bearing 200 of this disclosure can be completely limited, and correspondingly, the various components of the robot joint 100 have a defined connection relationship.
[0087] In addition, at least a portion of the projection of the second support bearing 200 of this disclosure onto the axis of the hollow shaft 140 coincides with at least a portion of the projection of the drive device 110 onto the axis of the hollow shaft 140. As a result, the second support bearing 200 can be recessed into the internal space of the drive device, reducing the axial dimension of the robot joint and making the robot joint of this disclosure more compact.
[0088] The robot joint 100 disclosed herein also includes a braking device 230 for braking the rotor 112. In a preferred embodiment, the braking device 230 is a permanent magnet brake (also known as a hollow motor brake); the permanent magnet brake can be implemented using products in the prior art (such as products sold on platforms like Taobao). Specifically, the braking device 230 may include a friction plate and a fixing part, the fixing part may include a cylindrical housing and a permanent magnet and an electromagnet disposed within the cylindrical housing; the fixing part can be fixed to the housing part 150, the friction plate is disposed on the rotor 112, and the friction plate cannot rotate relative to the rotor 112, but can generate a certain axial displacement relative to the rotor 112.
[0089] At this time, the rotor 112 has a concave structure, and the friction plate and at least part of the fixing part can be located within the concave structure of the rotor 112, thereby making full use of the internal space of the drive device in the robot joint of this disclosure. In addition, the braking device 230 has a large hollow structure, which allows the hollow shaft to pass through the braking device 230, achieving axial overlap and radial containment, making full use of the internal space of the joint and reducing the axial dimension of the robot joint.
[0090] When the electromagnet is not energized (normal state), the fixed part attracts the friction plate to the end face, and the two are squeezed to generate friction, which is used for rotation braking; when the electromagnet is energized, the coil generates a magnetic field opposite to the magnetic field of the permanent magnet, thereby canceling the attraction of the permanent magnet on the friction plate. The friction plate leaves the fixed part under the action of the spring plate, thereby releasing the rotor 112.
[0091] In a preferred embodiment, the braking device 230 can be fixed to the end of the housing portion 150 by a disc-shaped bracket.
[0092] The robot joint 100 disclosed herein may further include a high-speed side encoder assembly 240 and a low-speed side encoder assembly 250; the high-speed side encoder assembly 240 includes a high-speed side encoder code disk 241 and a high-speed side encoder reading head 242, the high-speed side encoder code disk 241 being fixedly connected to the rotor 112; the high-speed side encoder reading head 242 is used to read information from the high-speed side encoder code disk 241 and obtain the motion state of the rotor 112. The motion state of the rotor 112 includes information such as the speed and position of the rotor 112.
[0093] The low-speed side encoder assembly 250 includes a low-speed side encoder code disk 251 and a low-speed side encoder reading head 252. The low-speed side encoder code disk 251 is fixedly connected to the hollow shaft 140. The low-speed side encoder reading head 252 is used to read the information from the low-speed side encoder code disk 251 and obtain the motion state of the output flange 130. The motion state of the output flange 130 includes information such as the speed and position of the output flange 130.
[0094] Specifically, the high-speed side encoder disk 241 of the high-speed side encoder assembly 240 is fixedly connected to the rotor 112 via a first bracket 270, which is rotatably mounted on the hollow shaft 140 via a second bearing 260.
[0095] Furthermore, the braking device 230 is located between the first support 270 and the drive device 110. Thus, the axial dimension of the robot joint 100 disclosed herein can be reduced through the ingenious arrangement of the various components.
[0096] The first support 270 of this disclosure includes a first recessed region and a second recessed region. The high-speed side encoder code disk 241 is located in the first recessed region, and the low-speed side encoder code disk 251 is located in the second recessed region. In addition, the high-speed side encoder code disk 241 and the low-speed side encoder code disk 251 are at the same or approximately the same position in the axial direction of the hollow shaft 140; the high-speed side encoder code disk 241 is further away from the hollow shaft 140 than the low-speed side encoder code disk 251.
[0097] In other words, the high-speed side encoder assembly disclosed herein is a larger magnetic encoder, and the low-speed side encoder assembly is a smaller magnetic encoder. The larger magnetic encoder covers the smaller magnetic encoder, making full use of the axial space of the magnetic encoder and ensuring control over the running accuracy.
[0098] In this disclosure, the low-speed side encoder disk 251 is disposed on the hollow shaft 140 via a second bracket 280, wherein at least a portion of the second bracket 280 is located within a second recessed area.
[0099] Meanwhile, the second bracket 280 can limit one end of the inner ring of the second bearing. Thus, the high-speed side encoder assembly and the low-speed side encoder assembly are connected through the second bearing, ensuring the coaxiality between the magnetic encoders and improving the structural rigidity.
[0100] In a preferred embodiment, a magnetic material is provided between the high-speed side encoder reading head and the low-speed side encoder reading head, thereby avoiding mutual interference between the magnetic encoders and preventing the two reading heads from reading the magnetic encoder information incorrectly.
[0101] In this disclosure, the second bracket 280 and the hollow shaft 140 can be connected by means of nut tightening, wedge-shaped cover, elastic fastening cover, etc., to avoid relative sliding between the low-speed side encoder assembly and the hollow shaft, so as to prevent the low-speed side encoder assembly from coming off.
[0102] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.
[0103] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0104] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.
Claims
1. A robot joint, characterized in that, include: A drive unit for providing driving force; A harmonic reducer, comprising a wave generator, a flexible wheel, and a rigid wheel; the drive device is connected to the wave generator to transmit driving force to the harmonic reducer; The output flange is provided with a rigid wheel of the harmonic reducer connected to the output flange via a first bearing; the flexible wheel of the harmonic reducer is fixedly connected to the output flange; the first bearing is a crossed roller bearing, the output flange is fixed to the outer ring of the first bearing, and the rigid wheel of the harmonic reducer is fixed to the inner ring of the first bearing; A hollow shaft is provided, one end of which is connected to the output flange, and the output flange and the hollow shaft have the same axis of rotation and rotate synchronously; the other end of the hollow shaft passes through the harmonic reducer, and a first support bearing is provided between the wave generator and the hollow shaft.
2. The robot joint according to claim 1, characterized in that, The wave generator has a central hole, the hollow shaft passes through the central hole of the wave generator, the inner ring of the first support bearing is sleeved on the hollow shaft, and the outer ring of the first support bearing is disposed in the central hole of the wave generator.
3. The robot joint according to claim 2, characterized in that, Also includes: A bearing housing is rotatably mounted on the wave generator via a second support bearing, wherein the bearing housing is fixedly connected to the rigid wheel of the harmonic reducer.
4. The robot joint according to claim 3, characterized in that, The wave generator of the harmonic reducer includes a shoulder, and one end of the inner ring of the second support bearing is positioned by the shoulder of the wave generator.
5. The robot joint according to claim 4, characterized in that, The other end of the inner ring of the second support bearing is positioned by a baffle fixed to the wave generator.
6. The robot joint according to claim 3, characterized in that, The bearing housing includes a stepped portion, which is used to limit the position of one end of the outer ring of the second support bearing.
7. The robot joint according to claim 3, characterized in that, A limiting component is fixed on the bearing housing, and the limiting component is used to limit the position of the other end of the outer ring of the second support bearing.
8. The robot joint according to claim 3, characterized in that, Along the axial direction of the hollow shaft, at least a portion of the projection of the second support bearing onto the axis of the hollow shaft coincides with at least a portion of the projection of the drive device onto the axis of the hollow shaft.
9. The robot joint according to claim 1, characterized in that, The driving device includes a rotor, which is fixedly connected to the wave generator.
10. The robot joint according to claim 9, characterized in that, It also includes a braking device for braking the rotor.
11. The robot joint according to claim 10, characterized in that, The rotor has a concave structure, and at least a portion of the braking device is located within the concave structure of the rotor.
12. The robot joint according to claim 10, characterized in that, It also includes a high-speed side encoder assembly, which includes a high-speed side encoder code disk and a high-speed side encoder reading head. The high-speed side encoder code disk is fixedly connected to the rotor. The high-speed side encoder reading head is used to read the information from the high-speed side encoder code disk and obtain the motion state of the rotor.
13. The robot joint according to claim 12, characterized in that, It also includes a low-speed side encoder assembly, which includes a low-speed side encoder code disk and a low-speed side encoder reading head. The low-speed side encoder code disk is fixedly connected to the hollow shaft, and the low-speed side encoder reading head is used to read the information of the low-speed side encoder code disk and obtain the motion state of the output flange.
14. The robot joint according to claim 13, characterized in that, The high-speed side encoder disk is fixedly connected to the rotor via a first bracket, and the first bracket is rotatably mounted on the hollow shaft via a second bearing.
15. The robot joint according to claim 14, characterized in that, The braking device is located between the first bracket and the driving device.
16. The robot joint according to claim 14, characterized in that, The first bracket includes a first recessed area and a second recessed area, the high-speed side encoder code disk is located in the first recessed area, and the low-speed side encoder code disk is located in the second recessed area.
17. The robot joint according to claim 16, characterized in that, The high-speed side encoder disk and the low-speed side encoder disk are positioned at the same or approximately the same axial position on the hollow shaft.
18. The robot joint according to claim 17, characterized in that, The high-speed side encoder disk is further away from the hollow shaft than the low-speed side encoder disk.
19. The robot joint according to claim 16, characterized in that, The low-speed side encoder disk is mounted on the hollow shaft via a second bracket, wherein at least a portion of the second bracket is located within the second recessed area.