Joint structure and robot

Abstract

The invention discloses a joint structure and a robot, relates to the technical field of robots, optimizes the structural design, is compact and reasonable in structure, and meets the lightweight requirement. The joint structure comprises an output piece, a harmonic speed reducer and a motor assembly. The harmonic speed reducer comprises an input shaft and an output part, the output part is in transmission connection with the output part, the input shaft extends in the axial direction, and the length of the input shaft is larger than that of the output part in the axial direction. The motor assembly is used for providing power and comprises a motor shell, a stator, a rotor and a motor fixing shaft, the motor fixing shaft is fixedly connected with the input shaft and the rotor, the motor fixing shaft is located between the input shaft and the rotor, and the stator surrounds the rotor.

Description

Technical Field

[0001] This application relates to the technical field of robots, and in particular to a joint structure and a robot. Background Art

[0002] With the development of technology, the demand for robots to be applied in practice is becoming increasingly urgent. In particular, humanoid robots are required to be able to perform various flexible movements with stable gaits, which poses a higher challenge to the lightweight design of the entire robot. Most robot joints adopt the harmonic reducer solution. Currently, the harmonic reducer has been widely used in robot products such as industrial robots and collaborative robots. However, industrial robots do not have lightweight requirements, and the overall design weight of the harmonic reducer is too heavy. Considering the connection with other structural components such as motors, the weight of the entire joint module will be even heavier, making it unsuitable for robot scenarios with lightweight requirements. Summary of the Invention

[0003] This application provides a joint structure and a robot, which optimize the structural design, are compact and reasonable, and meet the lightweight requirements.

[0004] In a first aspect, a joint structure provided by this application includes an output member, a harmonic reducer, and a motor assembly; wherein, the harmonic reducer includes an input shaft and an output portion, the output portion is in transmission connection with the output member, the input shaft extends along the axial direction, and along the axial direction, the length of the input shaft is greater than the length of the output portion; the motor assembly is used to provide power and includes a motor housing, a stator, a rotor, and a motor fixed shaft. The stator is fixed on the motor housing, the motor fixed shaft is fixedly connected to the input shaft and the rotor, the motor fixed shaft is located between the input shaft and the rotor, and the stator surrounds the rotor.

[0005] The joint structure provided by the embodiment of the present application has the motor assembly providing power through the electromagnetic force between the stator and the rotor. The motor fixed shaft is fixedly connected to the input shaft and the rotor, and the motor fixed shaft is located between the input shaft and the rotor. The stator surrounds the rotor, and the output part of the harmonic reducer is in transmission connection with the output part. In this way, when the rotor rotates, it drives the input shaft of the harmonic reducer to rotate. After being decelerated by the harmonic reducer, the output part drives the output part to rotate, and the output part can drive the corresponding structure of the robot to output corresponding actions. Since the length of the input shaft in the axial direction is greater than the length of the output part, the input shaft can directly extend into the middle of the motor assembly, so that at least the stator in the motor assembly can be conveniently connected to the input shaft without additionally adding a structure connected in the axial direction between the input shaft of the harmonic reducer and the motor assembly, reducing the number of connecting components, making the transmission chain shorter and the transmission more effective, and reducing the weight of the entire joint structure. In addition, in the related art, in the scheme of additionally designing a connecting structure, when connecting the input shaft, it is often necessary to extend into the inner diameter of the input shaft for radial interference fit. However, this will inevitably occupy the inner diameter size, reducing the inner diameter size and being unfavorable for the normal passage of communication and power lines. On this basis, if the normal passage of the lines is to be ensured, the overall size of the original harmonic reducer needs to be increased, which will increase the weight of the entire harmonic reducer. Since the input shaft of the harmonic reducer of the present application can be directly assembled with the motor assembly, the inner diameter thereof will not be affected by the installation and assembly, ensuring the normal passage of communication and power lines, and thus not increasing the size of the harmonic reducer, improving the transmission reliability and the lightweight effect.

[0006] Therefore, the joint structure provided by the embodiment of the present application reduces the number of connecting components, improves the transmission reliability, optimizes the structural design, is structurally compact and reasonable, and meets the lightweight requirements.

[0007] In a possible implementation manner of the present application, the input shaft includes an integrally formed transmission section and an extension section. The transmission section is located inside the radial direction of the output part, and the extension section extends axially from the transmission section and extends beyond the output part in the axial direction. The motor fixed shaft surrounds the outer side of the diameter of the extension section.

[0008] In a possible implementation manner of the present application, a connecting structure is formed on the outer wall of the diameter of the extension section. The inside of the motor assembly is hollow, and at least part of the extension section extends into the motor assembly. The motor assembly is connected to the input shaft through the connecting structure.

[0009] In a possible implementation manner of the present application, the connecting structure includes a first connecting surface provided on the extension section. The motor fixed shaft is annular and is sleeved and fixed on the first connecting surface.

[0010] In a possible implementation of the present application, a fixing hole is provided on the motor fixed shaft, and the rotor is detachably connected to the motor fixed shaft by fitting and connecting with the fixing hole through a fastener.

[0011] In a possible implementation of the present application, the connecting structure further includes a second connecting surface and a third connecting surface provided on the extension section. The first connecting surface is located between the second connecting surface and the third connecting surface. The first bearing and the second bearing are respectively installed on the second connecting surface and the third connecting surface, and the motor housing is rotatably connected to the extension section of the input shaft through the first bearing and the second bearing.

[0012] In a possible implementation of the present application, the motor housing includes a mounting flange and a housing member. One end of the housing member has an opening, and the opening is fixed on the mounting flange. The stator and the rotor are accommodated in the space formed by the mounting flange and the housing member. The mounting flange is installed on the second connecting surface through the first bearing, and the housing member is installed on the third connecting surface through the second bearing.

[0013] In a possible implementation of the present application, the joint structure further includes a fixing ring, and the connecting structure further includes a fourth connecting surface provided on the extension section. The fourth connecting surface is located between the second connecting surface and the first connecting surface. The fixing ring is provided on the fourth connecting surface and abuts against one side of the first bearing.

[0014] In a possible implementation of the present application, along the radial direction of the input shaft, the second connecting surface is higher than the fourth connecting surface and lower than the fixing ring. The fourth connecting surface has an external thread, and the fixing ring has an internal thread. The fixing ring and the fourth connecting surface are threadedly connected.

[0015] In a possible implementation of the present application, the joint structure further includes a control component. The control component includes an outer magnetic ring and an outer fixing member. The connecting structure further includes a fifth connecting surface provided on the extension section. The outer fixing member is fixed on the fifth connecting surface, and the outer magnetic ring is fixed on the outer fixing member.

[0016] In a possible implementation of the present application, along the axial direction of the input shaft, the second connecting surface, the fourth connecting surface, the first connecting surface, the third connecting surface, and the fifth connecting surface are arranged in sequence, and the heights of the second connecting surface, the fourth connecting surface, the first connecting surface, the third connecting surface, and the fifth connecting surface along the radial direction decrease in sequence.

[0017] In a possible implementation of the present application, the control component further includes an inner magnetic ring and an inner fixing member. The input shaft penetrated by the output member and exceeds the input shaft. The inner fixing member is fixed on the output member, and the inner magnetic ring is fixed on the inner fixing member and is located inside the outer magnetic ring.

[0018] In a possible implementation manner of the present application, the harmonic reducer further includes a wave generator, a flexible gear, and a rigid gear. The input shaft is the input end of the wave generator, the flexible gear is the output part, sleeved outside the wave generator, the outer part of the flexible gear meshes with the inner tooth profile of the rigid gear, the flexible gear is connected to the output member, and the rigid gear is fixed to the motor housing;

[0019] The rigid gear is provided with a plurality of weight reduction holes, and the plurality of weight reduction holes are at least used to connect to an external structure.

[0020] In a second aspect, the present application provides a robot, including the joint structure of any one of the first aspects.

[0021] The robot of the present application, due to including the joint structure of any one of the first aspects, thus has the same technical effects, that is, the structural design is optimized, the structure is compact and reasonable, and it meets the lightweight requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0023] Figure 1 is one of the three-dimensional structure diagrams of the joint structure provided by the embodiment of the present application;

[0024] Figure 2 is the second three-dimensional structure diagram of the joint structure provided by the embodiment of the present application;

[0025] Figure 3 is the exploded structure diagram of the joint structure provided by the embodiment of the present application;

[0026] Figure 4 is the cross-sectional structure diagram of the joint structure provided by the embodiment of the present application;

[0027] Figure 5 is the three-dimensional structure diagram of the harmonic reducer of the joint structure provided by the embodiment of the present application;

[0028] Figure 6 is the cross-sectional structure diagram of the harmonic reducer of the joint structure provided by the embodiment of the present application;

[0029] Figure 7 is the structure diagram of the motor fixed shaft of the joint structure provided by the embodiment of the present application;

[0030] Figure 8 is the structure diagram of the fixing ring of the joint structure provided by the embodiment of the present application.

[0031] Description of the reference numerals:

[0032] 1 - Output part; 11 - Hollow part; 2 - Harmonic reducer; 21 - Input shaft; 211 - Transmission section; 212 - Extension section; 213 - Connection structure; 2131 - First connection surface; 2132 - Second connection surface; 2133 - Third connection surface; 2134 - Fourth connection surface; 2135 - Fifth connection surface; 2136 - Anti - rotation plane; 22 - Output section; 23 - Wave generator; 24 - Steel gear; 241 - Weight - reducing hole; 3 - Motor assembly; 31 - Motor housing; 311 - Mounting flange; 312 - Shell component; 32 - Stator; 33 - Rotor; 34 - Motor fixed shaft; 341 - Fixed hole; 35 - First bearing; 36 - Second bearing; 37 - Third bearing; 38 - Sealing ring; 39 - Bearing gland; 4 - Fixed ring; 5 - Control component; 51 - Outer magnetic ring; 52 - Outer fixing part; 53 - Inner magnetic ring; 54 - Inner fixing part; 55 - Drive and control board; 6 - Servo rear cover; 7 - Oil seal. Specific embodiments

[0033] Hereinafter, embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and the above - mentioned drawings of this application are intended to cover non - exclusive inclusion.

[0035] In the description of the embodiments of the present application, technical terms such as "first", "second", "third", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary - secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0036] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0038] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0039] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0040] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0041] Below, this application is described in detail.

[0042] In an embodiment of the present application, a robot is provided, comprising a joint structure. The joint structure is applied to the robot, and torque feedback is implemented at each joint, which can achieve a more precise force control effect and ensure the rigidity and stability of the system.

[0043] The robot can be a multi-degree-of-freedom robotic arm, a leg-type robot, a wheeled robot, etc. As long as it is a robot with joints, the above joint structure is applicable.

[0044] In some embodiments, the robot is a six-degree-of-freedom robotic arm, and the joint structure can be integrated and applied as each joint of the robotic arm.

[0045] In some other embodiments, the robot is a humanoid robot, and the joint structure is integrated and applied as the joints of the humanoid robot, including but not limited to the ankle joint, knee joint, hip joint of the leg, the waist joint of the torso, and the shoulder joint, elbow joint, wrist joint in the arm, etc.

[0046] In some other embodiments, the robot is a quadruped robot, and the above joint structure is integrated and applied as the joints of the quadruped robot.

[0047] For the robot of the embodiments of the present application, in order to meet the requirements of light weight, a new design is made for the joint structure. Therefore, the embodiments of the present application provide a robot and also provide a joint structure.

[0048] Specifically, referring to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 , a joint structure provided by the present application includes an output member 1, a harmonic reducer 2, and a motor assembly 3; wherein, the harmonic reducer 2 includes an input shaft 21 and an output portion 22, the output portion 22 is in transmission connection with the output member 1, the input shaft 21 extends along the axial direction, and along the axial direction, the length of the input shaft 21 is greater than the length of the output portion 22; the motor assembly 3 is used to provide power and includes a motor housing 31, a stator 32, a rotor 33, and a motor fixed shaft 34. The stator 32 is fixed on the motor housing 31, the motor fixed shaft 34 is fixedly connected with the input shaft 21 and the rotor, the motor fixed shaft 34 is located between the input shaft 21 and the rotor 33, and the stator 32 surrounds the rotor 33.

[0049] The joint structure provided by the embodiment of the present application, the motor assembly 3 provides power through the electromagnetic force between the stator 32 and the rotor 33. The motor fixed shaft 34 is fixedly connected to the input shaft 21 and the rotor. The motor fixed shaft 34 is located between the input shaft 21 and the rotor 33. The stator 32 surrounds the rotor 33. The output part 22 of the harmonic reducer 2 is in transmission connection with the output member 1. In this way, when the rotor 33 rotates, it drives the input shaft 21 of the harmonic reducer 2 to rotate. After being decelerated by the harmonic reducer 2, the output part 22 drives the output member 1 to rotate. The output member 1 can drive the corresponding structure of the robot to output corresponding actions. Since the length of the input shaft 21 in the axial direction is greater than the length of the output part 22, the input shaft 21 can directly extend into the middle of the motor assembly 3, so that at least the stator 32 in the motor assembly 3 can be conveniently connected to the input shaft 21, without the need to additionally add a structure connected in the axial direction between the input shaft 21 of the harmonic reducer 2 and the motor assembly 3, reducing the number of connecting components, and making the transmission chain shorter and the transmission more effective, reducing the weight of the entire joint structure. In addition, in the related art, a scheme of additionally designing a connecting structure 213 often needs to extend into the inner diameter of the input shaft 21 for radial interference fit when connecting the input shaft 21. However, this will inevitably occupy the inner diameter size, reducing the inner diameter size, which is not conducive to the normal passage of communication and power lines. On this basis, if the normal passage of the lines is to be ensured, the overall size of the original harmonic reducer 2 needs to be increased, increasing the weight of the entire harmonic reducer 2. Since the input shaft 21 of the harmonic reducer 2 of the present application can be directly assembled with the motor assembly 3, the inner diameter of its inner side will not be affected by the installation and assembly, ensuring the normal passage of communication and power lines, and thus not increasing the size of the harmonic reducer 2, improving the transmission reliability and the lightweight effect.

[0050] Therefore, the joint structure provided by the embodiment of the present application reduces the number of connecting components, improves the transmission reliability, optimizes the structural design, is structurally compact and reasonable, and meets the lightweight requirements.

[0051] Referring to Figure 4 、 Figure 5 and Figure 6 In the joint structure of the embodiment of the present application, the harmonic reducer 2 may include a wave generator 23, a flexspline, and a circular spline 24. Among them, the input shaft 21 is the input end of the wave generator 23, the flexspline is the output part 22, sleeved outside the wave generator 23, the outer part of the flexspline meshes with the inner tooth profile of the circular spline 24, the flexspline is connected to the output member 1, and the circular spline 24 is fixed to the motor housing 31.

[0052] That is, the harmonic reducer 2 in the joint structure of the embodiment of the present application is mainly composed of three core components: a wave generator 23, a flexspline, and a rigid ring. Its power transmission process realizes flexible meshing transmission through elastic deformation. Specifically, the wave generator 23 is fixed to the input shaft 21, and its elliptical contour forms a rotatable cam structure through a thin-walled ball bearing. When the input shaft 21 drives the wave generator 23 to rotate, the elliptical wave generator 23 applies a radial force to the thin-walled cup-shaped structure of the flexspline, causing the elastic body of the flexspline to produce periodic wave-like deformation, similar to the wave deformation generated when a circular rubber ring is pinched into an ellipse.

[0053] The external gear ring of the flexspline and the internal gear ring of the rigid ring adopt a special tooth profile matching design, and the difference in the number of teeth between the two is usually an integer multiple of 2. When the wave generator 23 rotates, it drives the flexspline to elastically deform, resulting in a progressive displacement of the meshing area between its external teeth and the internal teeth of the rigid ring along the circumferential direction. Specifically, a complete meshing area is formed in the long axis direction of the wave generator 23, a maximum disengagement gap is generated in the short axis direction, and a gradually changing semi-meshing state is presented in the area between the two. Since the rigid ring is fixed and immovable, when the wave generator 23 rotates one week, the tooth ring of the flexspline will produce a reverse displacement of (the number of teeth of the rigid ring - the number of teeth of the flexspline) tooth pitches relative to the rigid ring, thereby achieving motion deceleration. For example, when the rigid ring has 202 teeth and the flexspline has 200 teeth correspondingly, rotating the input shaft 21 one week will drive the flexspline to move 2 teeth in the reverse direction, obtaining a reduction ratio of 100:1.

[0054] Therefore, the harmonic reducer 2 in the joint structure of the embodiment of the present application realizes backlash-free transmission through elastic deformation, and the anti-fatigue characteristics of the flexspline material ensure the reliability under long-term repeated deformation. Its compact structure combines a high reduction ratio with precise transmission characteristics, and is particularly suitable for scenarios such as robot joints that require high-torque precision speed regulation. Compared with traditional gearboxes, this design eliminates backlash errors, significantly reduces the overall volume and weight while maintaining high transmission accuracy.

[0055] On this basis, in order to further reduce the overall weight of the joint structure, referring to Figure 5 , a plurality of weight reduction holes 241 are provided on the rigid ring 24, and the plurality of weight reduction holes 241 are at least used to connect to an external structure.

[0056] Since the rigid ring 24 of the harmonic reducer 2 is rigid and fixed, it can be fixed to the base bracket of the joint structure (such as a motor housing, etc.), or can be used as a connecting structural component when the joint structure is assembled into a robot. Both of the above connections can be realized through the weight reduction holes 241 opened on the rigid ring 24 of the harmonic reducer 2. For example, the plurality of weight reduction holes 241 can be used for the connection between the joint structure and the robot torso or skeleton.

[0057] In some embodiments, the plurality of weight reduction holes 241 may be through holes for the fasteners to pass through to achieve fixation; the plurality of weight reduction holes 241 may also be threaded holes for mating connection with threaded fasteners.

[0058] In some embodiments, the plurality of weight reduction holes 241 may be arranged at intervals along the circumferential direction of the steel wheel 24. Further, the plurality of weight reduction holes 241 may be arranged at uniform intervals. Moreover, the plurality of weight reduction holes 241 may be arranged close to the outer edge of the steel wheel 24 in the radial direction.

[0059] For easy implementation and a more compact structure, referring to Figure 6 , in some embodiments, the input shaft 21 includes an integrally formed transmission section 211 and an extension section 212. The transmission section 211 is located inside the output section 22 in the radial direction. The extension section 212 extends axially from the transmission section 211 and extends beyond the output section 22 in the axial direction. The motor fixed shaft 34 surrounds the outside of the extension section 212.

[0060] Here, the input shaft 21 includes a transmission section 211 and an extension section 212. Among them, the transmission section 211 refers to the part located inside the output section 22 in the radial direction, that is, the transmission section 211 is located inside the steel wheel 24 and the flexspline of the harmonic reducer 2 in the axial direction. The extension section 212 is the part that exceeds the steel wheel 24 and the flexspline. It is precisely due to the setting of the extension section 212 that the harmonic reducer 2 can be conveniently connected to the rotor 33 of the motor. For ease of implementation, the transmission section 211 and the extension section 212 are integrally formed, that is, during production, the input shaft 21 is integrally formed. After the assembly of the harmonic reducer 2 is completed, the extension section 212 extends out of the steel wheel 24 and the flexspline, facilitating connection with the motor assembly 3. And it reduces the number of parts, reduces the weight, and avoids excessive connections, improving the reliability of the transmission.

[0061] On this basis, referring to Figure 4 and Figure 6 , a connection structure 213 is formed on the radially outer wall of the extension section 212. The inside of the motor assembly 3 is hollow. The extension section 212 at least partially extends into the motor assembly 3. The motor assembly 3 is connected to the input shaft 21 through the connection structure 213.

[0062] The motor fixed shaft 34 of the motor assembly 3 can be arranged on the radially outer wall of the extension section 212 instead of being connected to the end of the extension section 212. In this way, on the one hand, it does not affect the hole for the line to pass through the center of the input shaft 21. On the other hand, the rotor 33 and the stator 32 of the motor are both integrated in the radial direction of the input shaft 21, making the combination of the harmonic reducer 2 and the motor assembly 3 more compact, which can reduce the size of the entire joint structure and is beneficial to lightweight.

[0063] Specifically, referring to Figure 4 、Figure 6 and Figure 7 The connecting structure 213 includes a first connecting surface 2131 provided on the extended section 212. The motor fixed shaft 34 is annular and is sleeved and fixed on the first connecting surface 2131.

[0064] The provision of the first connecting surface 2131 facilitates the sleeved fixation of the annular motor fixed shaft 34 on the input shaft 21.

[0065] It should be noted that the first connecting surface 2131 may be an annular plane formed on the circumferential outer wall of the extended section 212. This annular plane may be smooth or a frosted surface with relatively high friction. At the same time, this annular plane may be convex or a groove. Correspondingly, the inner wall of the motor fixed shaft 34 is sleeved on the first connecting surface 2131 and can be adapted to the size and shape of the first connecting surface 2131.

[0066] The motor fixed shaft 34 may be in interference fit or clearance fit with the first connecting surface 2131. The motor fixed shaft 34 and the input shaft 21 can be fixed by set screws, key pins, etc., or can be directly adhesively fixed.

[0067] In the joint structure of the embodiment of the present application, the connection mode between the motor fixed shaft 34 and the rotor 33 may be a fixed connection mode such as adhesion, or a detachable connection mode. Refer to Figure 4 and Figure 7 , in some embodiments, the motor fixed shaft 34 is provided with a fixing hole 341, and the rotor 33 is detachably connected to the motor fixed shaft 34 by being cooperatively connected with the fixing hole 341 through a fastener.

[0068] In this way, the rotor 33 can be conveniently fixed on the motor fixed shaft 34 through the fastener.

[0069] With such a design, when an abnormality occurs in the rotor 33 of the motor assembly 3 or the harmonic reducer 2, the rotor 33 can be conveniently removed by disassembling the fastener. Although the motor fixed shaft 34 is adhesively connected to the input shaft 21, the motor fixed shaft 34 is a common structural part with a low cost and a low scrapping cost. Therefore, the assembly and maintainability of the entire joint structure are greatly improved.

[0070] The extended section 212 of the input shaft 21 can be extended to the required length, facilitating the connection between the motor assembly 3 and it, and making the structure of the joint assembly compact. Among them, the connecting structure 213 may correspondingly also be multiple different structures provided at multiple different positions, so as to adapt to the connection of other components of the motor assembly 3.

[0071] Refer to Figure 4 and Figure 6, in some embodiments, the connecting structure 213 further includes a second connecting surface 2132 and a third connecting surface 2133 provided on the extension section 212. The first connecting surface 2131 is located between the second connecting surface 2132 and the third connecting surface 2133. The first bearing 35 and the second bearing 36 are respectively installed on the second connecting surface 2132 and the third connecting surface 2133. The motor housing 31 is rotatably connected to the extension section 212 of the input shaft 21 through the first bearing 35 and the second bearing 36.

[0072] In this way, by providing the second connecting surface 2132 and the third connecting surface 2133 on the extension section 212 and correspondingly providing the first bearing 35 and the second bearing 36, the motor housing 31 and the input shaft 21 can be rotatably connected. In this way, the motor housing 31 co-axially supports the input shaft 21 of the harmonic reducer 2 wave generator 23 through the first bearing 35 and the second bearing 36, ensuring the stable operation of the input shaft 21 without shaking. The motor housing 31 can be fixed to the first bearing 35 and the second bearing 36 by an interference fit or an adhesive connection method. The extension section 212 of the input shaft 21 can also be fixed to the first bearing 35 and the second bearing 36 by an interference fit or an adhesive connection method.

[0073] In some embodiments, referring to Figure 3 , Figure 4 , the motor housing 31 includes a mounting flange 311 and a housing member 312. One end of the housing member 312 has an opening, and the opening is fixed on the mounting flange 311. The stator 32 and the rotor 33 are accommodated in the space formed by the mounting flange 311 and the housing member 312. The mounting flange 311 is installed on the second connecting surface 2132 through the first bearing 35, and the housing member 312 is installed on the third connecting surface 2133 through the second bearing 36.

[0074] The mounting flange 311 and the housing member 312 together constitute the motor housing 31. The space formed by the mounting flange 311 and the housing member 312 is used to accommodate the stator 32 and the rotor 33. The first connecting surface 2131 is located between the second connecting surface 2132 and the third connecting surface 2133. That is, the rotor 33 and the stator 32 are accommodated in the motor housing 31, where the stator 32 is fixed to the motor housing 31.

[0075] The mounting flange 311 is installed on the second connecting surface 2132 through the first bearing 35, and the housing member 312 is installed on the third connecting surface 2133 through the second bearing 36, so that both sides of the motor housing 31 are rotatably connected to the input shaft 21 of the harmonic reducer 2 through bearings, and the rotor 33 is limited therein, making the rotation of the rotor 33 more stable and the structure of the overall joint structure more compact.

[0076] In some embodiments, in order to limit the movement of the input shaft 21 of the harmonic reducer 2 in the axial direction, referring toFigure 3 , Figure 4 and Figure 6 , the joint structure further includes a fixing ring 4, and the connecting structure 213 further includes a fourth connecting surface 2134 provided on the extension section 212. The fourth connecting surface 2134 is located between the second connecting surface 2132 and the first connecting surface 2131. The fixing ring 4 is provided on the fourth connecting surface 2134 and abuts against one side of the first bearing 35.

[0077] The extension section 212 is provided with a fourth connecting surface 2134. The fixing ring 4 can be provided on the fourth connecting surface 2134. By abutting the fixing ring 4 against one side of the first bearing 35, one side of the first bearing 35 is defined by the fixing ring 4, and the other side is the wave generator 23 of the harmonic reducer. That is, the input shaft 21 of the harmonic reducer is limited in the relative axial movement with respect to the mounting flange 311 through the limitation on both sides of the first bearing 35. Furthermore, the input shaft 21 of the entire wave generator 23 is fixed to prevent loosening and displacement during movement.

[0078] Of course, the fixing ring 4 and the fourth connecting surface 2134 of the extension section 212 can be in interference fit or bonded, or can be detachably connected.

[0079] For the convenience of installation, referring to Figure 4 , Figure 6 and Figure 8 , in some embodiments, along the radial direction of the input shaft 21, the second connecting surface 2132 is higher than the fourth connecting surface 2134 and lower than the fixing ring 4. The fourth connecting surface 2134 has an external thread, and the fixing ring 4 has an internal thread. The fixing ring 4 and the fourth connecting surface 2134 are threadedly connected.

[0080] That is, the fixing ring 4 and the fourth connecting surface 2134 of the extension section 212 are detachably connected by threads. In this way, during installation, the first bearing 35 can be first installed on the second connecting surface 2132, and then the fixing ring 4 is threadedly connected to the fourth connecting surface 2134. After tightening, it presses against one side of the first bearing 35 to achieve assembly.

[0081] Referring to Figure 3 , in some embodiments, a bearing gland 39 is provided at one end of the first bearing 35 away from the fixing ring 4, thereby fixing both sides of the first bearing 35.

[0082] Referring to Figure 3 and Figure 4 , in some embodiments of the joint structure of the embodiments of the present application, the joint structure further includes a control component 5. The control component 5 may include an outer magnetic ring 51 and an inner magnetic ring 53. The main functions of the outer magnetic ring 51 and the inner magnetic ring 53 are to suppress electromagnetic interference and ensure the working stability and accuracy of the motor control system.

[0083] In the case where the extension section 212 of the input shaft 21 can extend to the outer magnetic ring 51 and the inner magnetic ring 53, the outer magnetic ring 51 or the inner magnetic ring 53 can also be fixed to the input shaft 21 and connected through the connecting structure 213.

[0084] Referring to Figure 3 、 Figure 4 and Figure 6 , taking the outer magnetic ring 51 fixed on the input shaft 21 as an example, when the control component 5 includes the outer magnetic ring 51, the control component 5 further includes an outer fixing member 52, the connecting structure 213 further includes a fifth connecting surface 2135 provided on the extension section 212, the outer fixing member 52 is fixed on the fifth connecting surface 2135, and the outer magnetic ring 51 is fixed on the outer fixing member 52.

[0085] In this way, the outer magnetic ring 51 can also be integrally assembled on the input shaft 21, further improving the compactness of the joint structure and facilitating the lightweight design.

[0086] Referring to Figure 3 and Figure 4 , when the control component 5 further includes an inner magnetic ring 53, it can include an inner fixing member 54. The input shaft 21 through which the output member 1 passes extends beyond the input shaft 21. The inner fixing member 54 is fixed on the output member 1, and the inner magnetic ring 53 is fixed on the inner fixing member 54 and is located inside the outer magnetic ring 51. In this way, the connection and fixation of the inner magnetic ring 53 are achieved.

[0087] The outer fixing member 52 can be installed on the fifth connecting surface 2135 of the input shaft 21 of the wave generator 23 through a zero-clearance fit. The specific position can be against the boss of the wave generator 23 at the end of the input shaft 21 and fixed by a set screw. The outer magnetic ring 51 can be bonded to the outer fixing member 52. The inner fixing member 54 can be positioned through a zero-clearance fit and by the boss on the output member 1 and fixed by a set screw. The outer magnetic ring 51 and the inner magnetic ring 53 are in a coplanar state.

[0088] In the solution where the connecting structure 213 has a second connecting surface 2132, a fourth connecting surface 2134, a first connecting surface 2131, a third connecting surface 2133, and a fifth connecting surface 2135, referring to Figure 4 and Figure 6 , for the convenience of installation and layout, along the axial direction of the input shaft 21, the second connecting surface 2132, the fourth connecting surface 2134, the first connecting surface 2131, the third connecting surface 2133, and the fifth connecting surface 2135 are arranged in sequence, and the heights of the second connecting surface 2132, the fourth connecting surface 2134, the first connecting surface 2131, the third connecting surface 2133, and the fifth connecting surface 2135 in the radial direction decrease in sequence.

[0089] In this way, the corresponding components can be sequentially assembled with the input shaft 21 starting from the end of the input shaft 21 (i.e., the position close to the fifth connection surface 2135).

[0090] In addition, the second connection surface 2132 (which can be a cylindrical surface) of the first bearing 35 that supports the mounting flange 311, the fourth connection surface 2134 (which can be an external threaded cylindrical surface) that mates with the fixing ring 4, the first connection surface 2131 (which can be a motor bonding surface) that is bonded to the motor fixed shaft 34, the third connection surface 2133 (which can be a cylindrical surface) of the bearing that is supported in cooperation with the second bearing 36 on the housing member 312 of the motor housing 31, and the fifth connection surface 2135 (which can be an external magnetic ring 51 fixing surface) for fixedly installing the external fixing member 52 are all integrally integrated on the input shaft 21 of the wave generator 23, making the structural space more compact. At the same time, the diameter of the hollow part 11 in the middle of the harmonic reducer 2 meets certain dimensions and does not affect the inner diameter size of the output member 1 located therein.

[0091] Refer to Figure 5 , in some embodiments, a rotation stopping plane 2136 is further provided at the end of the extension section 212 of the input shaft 21, and the rotation stopping plane 2136 can enable the control component 5 to control the rotation state of the input shaft 21 through the rotation stopping plane 2136.

[0092] Refer to Figure 1 , Figure 3 and Figure 4 , the output member 1 in the embodiment of the present application can be an output flange, which has a hollow part 11 inside, and the hollow part 11 is used to accommodate communication or power lines. The diameter size requirement of the hollow part 11 needs to meet the passing of the lines. For example, the diameter of the hollow part 11 is greater than or equal to 13 mm.

[0093] In addition, refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , in some embodiments, the joint structure further includes a drive and control board 55 and a servo motor rear cover 6. The drive and control board 55 is fixed to the column of the motor housing 31 by screws. The end of the servo motor rear cover 6 is also provided with a third bearing 37 by interference fit or gluing. The servo motor rear cover 6 is assembled with the motor housing 31 by zero-clearance fit and locked and fixed by screws. The third bearing 37 on the servo motor rear cover 6 supports the end of the output flange, ensuring the smooth rotation of the end during the rotation of the output flange, ensuring the smooth operation of the inner magnetic ring 53 fixed on the output flange, and ensuring the accuracy of the magnetic ring encoder.

[0094] Refer to Figure 3 and Figure 4, there are sealing rings 38 or oil seals 7 between the output flange, the steel wheel 24 of the harmonic reducer 2 and the wave generator 23 to ensure that the grease filled in the cavity between the wave generator 23 and the steel wheel 24 does not leak out to the outer surface of the steering gear during movement. A sealing ring 38 is also installed between the mounting flange 311 and the harmonic reducer 2 to ensure that the grease is sealed and does not overflow.

[0095] In addition, array holes for accelerating heat dissipation are provided on the motor housing to facilitate the heat dissipation of the motor.

[0096] A robot provided by an embodiment of the present application, since it includes the joint structure of the above embodiment.

[0097] Therefore, it has the same technical effects, that is, the structural design is optimized, the structure is compact and reasonable, and it meets the requirements of light weight.

[0098] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way.

Claims

1. A joint structure, characterized in that, Comprising: An output member; A harmonic reducer, including an input shaft and an output part, the output part being in driving connection with the output member, the input shaft extending in the axial direction, and in the axial direction, the length of the input shaft being greater than the length of the output part; A motor assembly for providing power, including a motor housing, a stator, a rotor, and a motor fixed shaft, the stator being fixed on the motor housing, the motor fixed shaft being fixedly connected to the input shaft and the rotor, the motor fixed shaft being located between the input shaft and the rotor, and the stator surrounding the rotor.

2. The joint structure according to claim 1, wherein, The input shaft includes an integrally formed transmission section and an extension section, the transmission section being located inside the output part in the radial direction, the extension section extending axially from the transmission section and extending beyond the output part in the axial direction, and the motor fixed shaft surrounding the outside of the extension section.

3. The joint structure according to claim 2, wherein, A connection structure is formed on the radial outer wall of the extension section, the interior of the motor assembly is hollow, at least a part of the extension section extends into the motor assembly, and the motor assembly is connected to the input shaft through the connection structure.

4. The joint structure according to claim 3, wherein, The connection structure includes a first connection surface provided on the extension section, and the motor fixed shaft is annular and sleeved and fixed on the first connection surface.

5. The joint structure according to claim 4, wherein The motor fixed shaft is provided with fixing holes, and the rotor is detachably connected to the motor fixed shaft by being in mating connection with the fixing holes through fasteners.

6. The joint structure according to claim 4, wherein The connection structure further includes a second connection surface and a third connection surface provided on the extension section, the first connection surface being located between the second connection surface and the third connection surface, a first bearing and a second bearing are respectively installed on the second connection surface and the third connection surface, and the motor housing is rotatably connected to the extension section of the input shaft through the first bearing and the second bearing.

7. The joint structure according to claim 6, wherein The motor housing includes a mounting flange and a housing member, one end of the housing member has an opening, and the opening is fixed on the mounting flange, the stator and the rotor are accommodated in the space formed by the mounting flange and the housing member, the mounting flange is installed on the second connection surface through the first bearing, and the housing member is installed on the third connection surface through the second bearing.

8. The joint structure according to claim 7, characterized in that, The joint structure further includes a fixing ring, the connection structure further includes a fourth connection surface provided on the extension section, the fourth connection surface being located between the second connection surface and the first connection surface, the fixing ring is provided on the fourth connection surface and abuts against one side of the first bearing.

9. The joint structure according to claim 8, characterized in that In the radial direction of the input shaft, the second connection surface is higher than the fourth connection surface and lower than the fixing ring, the fourth connection surface has an external thread, the fixing ring has an internal thread, and the fixing ring and the fourth connection surface are threadedly connected.

10. The joint structure according to claim 7, wherein, The joint structure further includes a control component, the control component includes an outer magnetic ring and an outer fixing member, the connection structure further includes a fifth connection surface provided on the extension section, the outer fixing member is fixed on the fifth connection surface, and the outer magnetic ring is fixed on the outer fixing member.

11. The joint structure according to claim 10, characterized in that, Along the axial direction of the input shaft, the second connecting surface, the fourth connecting surface, the first connecting surface, the third connecting surface, and the fifth connecting surface are arranged in sequence, and the heights of the second connecting surface, the fourth connecting surface, the first connecting surface, the third connecting surface, and the fifth connecting surface in the radial direction decrease in sequence.

12. The joint structure according to claim 10, wherein, The control assembly further includes an inner magnetic ring and an inner fixing member. The input shaft penetrated by the output member extends beyond the input shaft. The inner fixing member is fixed on the output member, and the inner magnetic ring is fixed on the inner fixing member and is located inside the outer magnetic ring.

13. The joint structure according to any one of claims 1 to 12, characterized in that, The harmonic reducer further includes a wave generator, a flexspline, and a circular spline. The input shaft is the input end of the wave generator. The flexspline is the output part and is sleeved outside the wave generator. The outer part of the flexspline meshes with the inner tooth profile of the circular spline. The flexspline is connected to the output member, and the circular spline is fixed to the motor housing. A plurality of weight reduction holes are provided on the circular spline, and at least the plurality of weight reduction holes are used to connect to an external structure.

14. A robot, characterized in that, It includes the joint structure according to any one of claims 1 to 13.

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