Harmonic joint

Abstract

The invention provides a harmonic joint. The harmonic joint comprises a joint shell and a speed reducer assembly. A first limiting ring groove is formed in one end of the inner peripheral wall of the joint shell; the speed reducer assembly is arranged in the joint shell and comprises a rigid wheel and a rolling body. A second limiting ring groove corresponding to the first limiting ring groove in position is formed in the peripheral wall of the rigid wheel, and the second limiting ring groove and the first limiting ring groove form a limiting ring cavity. The rolling body is arranged in the limiting ring cavity, and the rolling body, the peripheral wall of the rigid wheel and the peripheral wall of the joint shell jointly form a rolling bearing structure.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power drive, and particularly to a harmonic joint. Background Art

[0002] A harmonic joint generally includes a fixed internal gear ring, a flexible gear, and a wave generator that causes radial deformation of the flexible gear. It uses a flexible gear to generate a controllable elastic deformation wave, causing relative tooth misalignment between the internal gear ring and the flexible gear to transmit power and motion. This transmission is essentially different from general gear transmissions and has particularities in meshing theory, set calculation, and structural design. Harmonic gear reducers have advantages such as high precision and high load-carrying capacity.

[0003] Currently, relatively many components are used during the assembly of harmonic joints on the market, resulting in a relatively long assembly dimension chain length and relatively large accumulation of coaxiality and axial position errors between multiple components, thereby affecting the structural compactness of the harmonic joint and reducing the error of the output torque.

[0004] In view of this, there is an urgent need for a harmonic joint with a new structure on the market to solve the problems of poor structural compactness, large accumulation of assembly errors, and low transmission accuracy caused by relatively many components of the harmonic joint in the prior art. Summary of the Invention

[0005] Embodiments of the present disclosure provide a harmonic joint for solving the problems existing in harmonic joints in the prior art.

[0006] The harmonic joint provided by the embodiments of the present disclosure includes a joint housing and a reducer assembly;

[0007] One end of the inner peripheral wall of the joint housing is provided with a first limiting ring groove;

[0008] The reducer assembly is disposed within the joint housing, and the reducer assembly includes an internal gear ring and rolling elements;

[0009] Wherein, a second limiting ring groove corresponding to the position of the first limiting ring groove is provided in the outer peripheral wall of the internal gear ring, and the second limiting ring groove and the first limiting ring groove form a limiting ring cavity;

[0010] The rolling elements are disposed within the limiting ring cavity, and the rolling elements, the outer peripheral wall of the internal gear ring, and the outer peripheral wall of the joint housing together constitute a rolling bearing structure.

[0011] In an implementable embodiment, the joint housing further includes a first limiting portion, and the first limiting portion is disposed on the inner peripheral wall of the joint housing;

[0012] The harmonic joint further includes a driving assembly, and the driving assembly is disposed within the joint housing for providing driving force for the reducer assembly;

[0013] The drive assembly includes a motor stator, and the motor stator is limited in the first limiting portion.

[0014] In an implementable embodiment, the joint housing further includes a second limiting portion, the second limiting portion is disposed on the inner peripheral wall of the joint housing, and is spaced apart from the first limiting portion;

[0015] The reducer assembly further includes a flexspline, the flexspline meshes with the internal gear ring of the rigid ring, and the flexspline is limited in the second limiting portion.

[0016] In an implementable embodiment, the harmonic joint further includes a wire passing cylinder, and the wire passing cylinder axially penetrates through the joint housing;

[0017] The drive assembly includes a motor shaft and a motor rotor, the motor shaft is rotatably supported on the first part of the wire passing cylinder, and the motor rotor is disposed on the motor shaft;

[0018] The reducer assembly includes a wave generator, the wave generator is fixed to the motor shaft, and the wave generator is rotatably supported on the second part of the wire passing cylinder.

[0019] In an implementable embodiment, the first part of the wire passing cylinder includes a fixing post, and the fixing post has a positioning surface perpendicular to the axial direction;

[0020] The drive assembly further includes a high-speed end encoder;

[0021] The high-speed end encoder includes a high-speed end encoder circuit board and a high-speed end encoder disk;

[0022] The high-speed end encoder circuit board is fixed to the positioning surface of the fixing post, and the high-speed end encoder disk is attached to the end surface of the motor shaft opposite to the positioning surface of the fixing post.

[0023] In an implementable embodiment, the drive assembly further includes a low-speed end encoder;

[0024] The low-speed end encoder includes a low-speed end encoder disk and a low-speed end encoder circuit board;

[0025] The low-speed end encoder disk is attached to the end surface of the rigid ring close to the drive assembly, and the low-speed end encoder circuit board is fixed to the inner peripheral wall of the joint housing in the radial direction and is opposite to the position of the low-speed end encoder circuit board.

[0026] In an implementable embodiment, the harmonic joint includes a joint output end cover, and the joint output end cover is fixed to one end of the rigid ring close to the opening of the joint housing;

[0027] The wire passing cylinder penetrates through the joint output end cover, and a first dynamic seal is provided between the wire passing cylinder and the joint output end cover;

[0028] A second dynamic seal is provided between the inner peripheral wall of the joint housing and the outer peripheral wall of the rigid ring near the opening of the joint housing, and the second dynamic seal is used to seal and isolate the limiting ring cavity from the external environment.

[0029] In one possible implementation, the harmonic joint includes a sealed end cap, which is fixed to one end of the joint housing close to the drive assembly, and a wire passing cylinder penetrates through the sealed end cap.

[0030] On the side of the sealed end cap facing the inside of the joint housing, a circuit board mounting cavity is formed; the drive assembly further includes a drive circuit board, which is arranged in the circuit board mounting cavity.

[0031] In one possible implementation, the flexspline is provided with a torque sensor.

[0032] In one possible implementation, the flexspline includes a thin-walled cylinder, and a temperature sensor for detecting the internal temperature is arranged on the thin-walled cylinder.

[0033] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. Description of the Drawings

[0034] By reading the following detailed description with reference to the drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present disclosure will become easily understood. In the drawings, several embodiments of the present disclosure are shown in an exemplary rather than restrictive manner, where:

[0035] In the drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0036] Figure 1 A half-sectional view of the harmonic joint provided by the embodiment of the present disclosure is shown;

[0037] Figure 2 A perspective view of the harmonic joint provided by the embodiment of the present disclosure is shown;

[0038] Figure 3 A front view of the flexspline in the harmonic joint provided by the embodiment of the present disclosure is shown;

[0039] Figure 4 Shown is Figure 1 A partial enlarged view at A in;

[0040] Figure 5 Shown is Figure 1 A partial enlarged view at B in;

[0041] Figure 6 Shown is Figure 1 A partial enlarged view at C in;

[0042] Figure 7 A side view of the flexspline in the harmonic joint provided by the embodiment of the present disclosure is shown.

[0043] Description of reference numerals in the figure: 1. Joint housing; 11. First limiting ring groove; 12. First limiting part;

[0044] 13. Sealing end cover; 131. Sealing edge; 132. Circuit board mounting cavity; 133. Socketing edge; 14. Joint output end cover; 141. First dynamic seal; 15. Second limiting part;

[0045] 2. Rigid gear; 21. Second limiting ring groove; 22. Second dynamic seal; 23. Limiting ring cavity; 24. Rolling element;

[0046] 3. Flexspline; 31. Torque sensor; 32. Thin-walled cylinder; 321. Temperature sensor;

[0047] 4. Wave generator;

[0048] 5. Driving assembly; 51. Motor stator; 52. Motor rotor; 53. Motor shaft;

[0049] 6. Wire passing cylinder; 61. First bearing; 62. Second bearing; 63. Socketing part; 64. Fixed column;

[0050] 7. Low-speed end encoder; 71. Low-speed end encoder code disc; 72. Low-speed end encoder circuit board;

[0051] 8. High-speed end encoder; 81. High-speed end encoder circuit board; 82. High-speed end encoder code disc. Detailed implementation manners

[0052] To make the objectives, features, and advantages of the present disclosure more obvious and understandable, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present disclosure.

[0053] The embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings.

[0054] The harmonic joint provided by some embodiments of the present disclosure includes a joint housing, a joint end cover, and a speed reducer assembly.

[0055] The joint housing and the joint end cover are important components of the harmonic joint, which play a role in structurally supporting and protecting the internal components and providing an installation reference for the internal components. For external mechanisms, the joint housing plays a role in integrating mechanical interfaces: the joint housing or the joint end cover transmits the output torque to the external mechanism and bears the external load at the same time; it can also provide standardized mounting holes or flanges to facilitate the integration of the harmonic joint.

[0056] The reducer assembly is the internal core part of this harmonic joint, and may include a rigid gear, a flexible gear, a wave generator, etc. The core principle of the reducer assembly is that: when the wave generator rotates, it causes the flexible gear to generate periodic elastic deformation, and a tooth misalignment movement occurs between the rigid gear and the flexible gear. By adjusting the relative number of teeth between the flexible gear and the rigid gear, different transmission ratios can be obtained.

[0057] The harmonic joint has both high precision, high rigidity and compactness, and can be applied to fields such as robots, aerospace, etc.

[0058] Figure 1 and Figure 2 Some embodiments of the present disclosure provide a harmonic joint. The harmonic joint includes a joint housing 1 and a reducer assembly.

[0059] As Figure 1 shown, a first limiting ring groove 11 is provided at one end of the inner peripheral wall of the joint housing 1. It can be understood that the first limiting ring groove 11 is formed at one end of the inner wall of the joint housing 1 and is arranged around the inner wall for one week, thus forming an annular groove. The cross-sectional shape of the first limiting ring groove 11 along the axial direction of the harmonic joint can be, for example, a V-shaped groove. It should be noted that the axial direction of the harmonic joint refers to the rotation center line of the harmonic joint.

[0060] The reducer assembly is arranged inside the joint housing 1. The reducer assembly includes a rigid gear 2 and rolling elements 24; wherein, a second limiting ring groove 21 corresponding to the position of the first limiting ring groove 11 is provided in the outer peripheral wall of the rigid gear 2. It can be understood that the second limiting ring groove 21 is provided on the outer wall of the rigid gear 2 and is arranged around the outer wall for one week, thus forming an annular groove. The cross-sectional shape of the second limiting ring groove 21 along the axial direction of the harmonic joint can be, for example, a V-shaped groove. The second limiting ring groove 21 and the first limiting ring groove 11 form a limiting ring cavity 23; the rolling elements 24 are arranged inside the limiting ring cavity 23, and the shape of the limiting ring cavity 23 matches that of the rolling elements 24. The rolling elements 24, the outer peripheral wall of the rigid gear 2 and the inner peripheral wall of the joint housing 1 together form a rolling bearing structure. The rolling elements 24 can be specifically but not limited to being set as needle rollers, cylindrical rollers or ball bearings. Optionally, the limiting ring cavity 23 can be, for example, the raceway of a crossed roller bearing, and the rolling bearing structure formed by the rolling elements 24, the outer peripheral wall of the rigid gear 2 and the inner peripheral wall of the joint housing 1 can be, for example, a crossed roller bearing.

[0061] When the harmonic joint is specifically assembled, the rolling elements 24 can be arranged in the first limiting ring groove 11 of the joint housing 1, and then the rigid gear 2 can be installed in the joint housing 1 for operations such as axis alignment, uniform pressure application, and pre-tightening force adjustment. In this way, the inner peripheral wall of the joint housing 1 and the outer peripheral wall of the rigid gear 2 can jointly form a rolling bearing structure through the rolling elements in the limiting ring cavity 23. Thus, there is no need to additionally set a bearing and an installation station for installing the bearing between the rigid gear 2 and the joint housing 1, which can effectively reduce the length of the assembly dimension chain of the harmonic joint, reduce the structural complexity, and improve the structural compactness.

[0062] When the harmonic joint of the present disclosure embodiment is specifically used, the rigid gear 2 of the speed reducer assembly serves as the output end, and the rigid gear 2 rotates relative to the joint housing 1 to output the speed and torque after the speed reducer increases the torque.

[0063] For the harmonic joint provided by the embodiment of the present disclosure, by recessing and arranging the first limiting ring groove 11 in the inner peripheral wall of the joint housing 1 and recessing and arranging the second limiting ring groove 21 in the outer peripheral wall of the rigid gear 2, the first limiting ring groove 11 and the second limiting ring groove 21 can be correspondingly matched to form a limiting ring cavity 23 for accommodating the rolling elements 24. It is equivalent to additionally using the joint housing 1 as a bearing outer ring and using the rigid gear 2 as a bearing inner ring. Thus, the joint housing 1, the rolling elements 24, and the rigid gear 2 are used as bearings, so that the harmonic joint does not need to additionally set a bearing, and there is no need to additionally set components such as a bearing shoulder and a bearing retaining ring for installing the bearing. On the premise of the same torque output, it has a higher power density ratio and mass density ratio; it reduces the length of the axial and radial assembly dimension chains of the harmonic joint itself, so that the structural compactness between the joint housing 1 and the rigid gear 2 can be higher, the assembly cumulative error can be smaller, and the transmission accuracy can also be higher.

[0064] In an optional embodiment, the harmonic joint further includes a driving assembly 5. The driving assembly 5 is arranged in the joint housing 1 and is used to provide driving force for the speed reducer assembly. The joint housing 1 further includes a first limiting portion 12, and the first limiting portion 12 is arranged on the inner peripheral wall of the joint housing 1; the driving assembly 5 includes a motor stator 51, and the motor stator 51 is limited to the first limiting portion 12.

[0065] Optionally, in combination with Figure 1 For further detailed description, the first limiting portion 12 can be integrally formed on the inner peripheral wall of the joint housing 1 and can be formed by changing the diameter of the inner peripheral wall of the joint housing 1. The first limiting portion 12 can be specifically but not limited to being set as a limiting platform to limit and install one side of the motor stator 51 in the driving assembly 5 on the first limiting portion 12.

[0066] In the embodiments of the present disclosure, the joint housing 1 is reused as the housing of the drive assembly 5, so that the reducer assembly and the drive assembly 5 are both installed inside the joint housing 1. The first limiting portion 12 of the joint housing 1 provides an installation station for limiting and installing the motor stator 51, enabling the motor stator 51 and the inner wall of the joint housing 1 to be more precisely coaxially aligned and assembled. Both the reducer assembly and the drive assembly 5 use the joint housing 1 as the installation reference. While simplifying the components of the harmonic joint, more precise axial installation coaxiality and assembly accuracy are provided.

[0067] In an alternative embodiment, the reducer assembly further includes a flexspline 3, and the flexspline 3 meshes with the internal gear ring of the rigid spline 2; the joint housing 1 further includes a second limiting portion 15, and the second limiting portion 15 is provided on the inner peripheral wall of the joint housing 1 and is spaced from the first limiting portion 12, and the flexspline 3 is limited at the second limiting portion 15.

[0068] Optionally, in Figure 1 For further detailed description, the second limiting portion 15 can be integrally formed on the inner peripheral wall of the joint housing 1 and can be formed by changing the caliber of the inner peripheral wall of the joint housing 1. The second limiting portion 15 can be specifically but not limited to being set as a limiting stop, and one side of the flexspline 3 is limited and installed at the second limiting portion 15.

[0069] It can be understood that the second limiting portion 15 is equivalent to protruding the inner wall of the joint housing 1 radially, and correspondingly providing an installation station for limiting and installing the flexspline 3, enabling the flexspline 3 and the inner wall of the joint housing 1 to be more precisely coaxially aligned and assembled. Both the reducer assembly and the drive assembly 5 use the joint housing 1 as the installation reference. While simplifying the components of the harmonic joint, more precise axial installation coaxiality and assembly accuracy are provided.

[0070] By respectively providing the first limiting portion 12 and the second limiting portion 15 on the inner peripheral wall of the joint housing 1 for respectively limiting and installing the motor stator 51 and the flexspline 3, providing installation and fixing positions for the reducer assembly and the drive assembly 5, and providing precise axial positions for the axial positions of the reducer assembly and the drive assembly 5, ensuring strict coaxiality between the joint housing 1, the reducer assembly, and the drive assembly, the processing can be completed in one clamping of the components, reducing the length of the assembly dimension chain, reducing the accumulated error, and avoiding the processing error caused by secondary clamping. Thus, it is beneficial to improve the assembly accuracy of the harmonic joint and reduce the processing difficulty of the processed parts.

[0071] Optionally, the reducer assembly and the drive assembly 5 are sequentially arranged along the axis of the harmonic joint inside the joint housing 1, the second limiting portion 15 is close to the reducer assembly and is provided on the inner peripheral wall of the joint housing 1, and the first limiting portion 12 is close to the drive assembly 5 and is provided on the inner peripheral wall of the joint housing 1.

[0072] Optionally, the inner diameter of the first limiting portion 12 is smaller than the inner diameter of the second limiting portion 15.

[0073] In an alternative embodiment, as Figure 1 shown, the harmonic joint further includes a wire passing cylinder 6, and the wire passing cylinder 6 is axially disposed through the joint housing 1 along the axis of the joint housing 1. Optionally, the wire passing cylinder 6 can be axially disposed through the inside of the joint housing 1 along the axis of the joint housing 1, and the wire passing cylinder 6 is coaxially disposed with the joint housing 1. The drive assembly 5 further includes a motor shaft 53 and a motor rotor 52. The motor shaft 53 is rotatably supported on a first portion of the wire passing cylinder 6, and the motor rotor 52 is disposed on the motor shaft 53. The reducer assembly includes a wave generator 4, and the wave generator 4 is fixed to the motor shaft 53 and is rotatably supported on a second portion of the wire passing cylinder 6.

[0074] In the embodiment of the present disclosure, the wire passing cylinder 6 is designed to be hollow to realize internal wiring, providing more optional ways for the application and installation of the harmonic joint. The motor shaft 53 is rotatably supported on a first portion of the wire passing cylinder 6, and the wave generator 4 is rotatably supported on a second portion of the wire passing cylinder 6. In this way, the wire passing cylinder 6 can not only realize internal wiring, but also provide rotational support for the wave generator 4 and the motor rotor 52, which can further reduce the assembly parts of the harmonic joint and improve the assembly compactness. Optionally, the wire passing cylinder 6 can be movably assembled and connected to the wave generator 4 and the motor rotor 52 through a first bearing 61 and a second bearing 62 respectively.

[0075] Optionally, along the axis of the harmonic joint, the first portion of the wire passing cylinder 6 is disposed away from the output end of the harmonic joint, and the second portion of the wire passing cylinder 6 is disposed close to the output end of the harmonic joint.

[0076] In an alternative embodiment, as Figure 1 shown, the drive assembly 5 further includes a high-speed encoder 8; the high-speed encoder 8 includes a high-speed encoder circuit board 81 and a high-speed encoder disk 82; the first portion of the wire passing cylinder 6 includes a fixing post 64, and the fixing post 64 has a positioning surface perpendicular to the axis; the motor shaft has an end surface opposite to the positioning surface of the fixing post 64, the high-speed encoder circuit board 81 is fixed on the positioning surface of the fixing post 64, and the high-speed encoder disk 82 is attached to the end surface of the motor shaft opposite to the positioning surface of the fixing post 64.

[0077] In an alternative embodiment, the first portion of the wire passing cylinder 6 has a portion with an increasing radial dimension, the fixing post 64 is disposed on the portion with the increasing radial dimension and has a positioning surface perpendicular to the axis. The high-speed encoder circuit board 81 of the high-speed encoder 8 in the drive assembly 5 is fixed on the positioning surface of the fixing post 64, and the high-speed encoder disk 82 is attached to the end surface of the motor shaft opposite to the positioning surface of the fixing post 64. In this way, the rotational information of the drive assembly 5 can be correspondingly acquired, and the axial dimension of the harmonic joint is not significantly increased.

[0078] The specific setting methods of the fixing column 64 in the above wire passing cylinder 6 and the high-speed end encoder 8 can make full use of the axial space of the harmonic joint. The embedded corresponding installation method of the high-speed end encoder circuit board 81 and the high-speed end encoder code disk 82 makes the layout of the high-speed end encoder 8 more compact and occupies less installation space, and can reduce the axial length of the harmonic joint to a certain extent.

[0079] Optionally, the end face of the motor shaft opposite to the positioning face of the fixing column 64 can be but is not limited to being set as follows: the motor shaft has a hollow structure, and an end face opposite to the positioning face of the fixing column 64 is formed inside the hollow structure.

[0080] In an alternative embodiment, as Figure 1 shown, the drive assembly 5 further includes a low-speed end encoder 7; the low-speed end encoder 7 includes a low-speed end encoder code disk 71 and a low-speed end encoder circuit board 72; the low-speed end encoder code disk 71 is attached to the end face of the rigid gear 2 close to the drive assembly 5, and the low-speed end encoder circuit board 72 is fixed to the inner peripheral wall of the joint housing 1 along the radial direction and is opposite to the position of the low-speed end encoder circuit board 72. Optionally, the low-speed encoder code disk 71 can be fixed by an adhesive method.

[0081] In the embodiment of the present disclosure, in the optional low-speed end encoder 7, the low-speed end encoder code disk 71 is attached to the end face of the rigid gear 2 perpendicular to the axial direction, and the low-speed end encoder circuit board 72 is fixed to the inner peripheral wall of the joint housing 1 along the radial direction. It can also be but is not limited to being fixed to the inner peripheral wall of the joint housing 1 by an embedded method and being opposite to the position of the low-speed end encoder circuit board 71, so that the rotation information of the rigid gear 2 can be correspondingly collected.

[0082] In the embodiment of the present disclosure, the specific setting methods of the low-speed end encoder code disk 71 and the low-speed end encoder circuit board 72 in the low-speed end encoder 7 also make full use of the axial space of the harmonic joint. The corresponding embedded installation method of the low-speed end encoder circuit board 72 can make the layout of the low-speed end encoder 7 more compact and occupy less installation space, and can also reduce the axial length of the harmonic joint to a certain extent.

[0083] In an alternative embodiment, as Figure 1 and Figure 6 shown, the harmonic joint includes a joint output end cover 14, and the joint output end cover 14 is fixed to one end of the rigid gear 2 close to the opening of the joint housing 1. The wire passing cylinder 6 penetrates through the joint output end cover 14, and a first dynamic seal 141 is provided between the wire passing cylinder 6 and the joint output end cover 14; a second dynamic seal 22 is provided at one end of the inner peripheral wall of the joint housing 1 close to the outer peripheral wall of the rigid gear 2, and the second dynamic seal 22 is used to seal off the limiting ring cavity 23 from the external environment.

[0084] In an alternative embodiment of the present disclosure, a joint output end cover 14 is correspondingly provided at one end of the flexspline 2 close to the opening of the joint housing 1, and the joint output end cover 14 is sealingly connected to the outer peripheral wall of the wire passing cylinder 6 through a first dynamic seal 141; optionally, a concave annular groove may be specifically provided in the inner edge wall of the joint output end cover 14, so that the first dynamic seal 141 can be correspondingly fitted into the concave annular groove. The outer peripheral wall of the wire passing cylinder 6 is sealingly connected through the first dynamic seal 141. Thus, the joint output end cover 14 can also seal the harmonic joint from the output end, eliminating the need for an additional sealing housing, reducing the overall external dimension of the harmonic joint and lowering the weight. Moreover, the first dynamic seal 141 effectively prevents external water vapor from entering the interior of the harmonic joint through the joint output end cover 14, enabling the harmonic joint with a hollow structure to be equally applicable to extreme working scenarios such as humid and underwater environments.

[0085] In an embodiment of the present disclosure, a second dynamic seal 22 is provided between the inner peripheral wall of the joint housing 1 and the outer peripheral wall of the flexspline 2 at one end close to the opening of the joint housing 1. The second dynamic seal 22 can also adopt a similar fitting method of the concave annular groove as the above-mentioned first dynamic seal 141. By sealingly connecting the outer peripheral wall of the flexspline 2 and the inner peripheral wall of the joint housing 1 through the second dynamic seal 22, the limit ring cavity 23 can be sealed off from the external environment. On the one hand, it can prevent the grease used to lubricate the rolling elements in the limit ring cavity 23 from leaking out, and on the other hand, it can also prevent external water vapor from entering the joint housing 1 through the gap between the flexspline 2 and the joint housing 1, further improving the waterproof and sealing grade of the harmonic joint.

[0086] In the implementation of the present disclosure, the second dynamic seal 22 can eliminate the need for a sealing end cover, reducing the structural complexity of the sealing part. While enabling the harmonic joint to have a hollow structure, it can reduce and optimize the axial dimension length of the harmonic joint.

[0087] In an alternative embodiment, the harmonic joint includes a sealing end cover 13. The sealing end cover 13 is fixed to one end of the joint housing 1 close to the drive assembly 5, and the wire passing cylinder 6 passes through the sealing end cover 13; a circuit board mounting cavity 132 is formed on the side of the sealing end cover 13 facing the interior of the joint housing 1; the drive assembly 5 further includes a drive circuit board, and the drive circuit board is disposed in the circuit board mounting cavity 132.

[0088] Optionally, in combination with Figure 1 and Figure 4For further detailed description, specifically, a sealing end cover 13 may be provided at one end of the first limiting portion 12 facing away from the joint housing 1, and the sealing end cover 13 has a sealing edge 131 inserted into the inner peripheral wall of the first limiting portion 12. The sealing edge 131 may be specifically set as an inner ring edge protruding from one side of the sealing end cover 13. In this way, when the sealing end cover 13 is assembled and covered with one end of the joint housing 1, the sealing edge 131 can be correspondingly and sealingly inserted and fixed to the inner peripheral wall of the first limiting portion 12, and the other side of the motor stator 51 is limited, jointly with the stepped retaining platform in the first limiting portion 12, to realize the axial installation limit of the motor stator 51.

[0089] Moreover, a static seal may be fixedly provided corresponding to the connecting corner of the sealing end cover 13 and the sealing edge 131. In this way, when the sealing end cover 13 is hermetically covered with one end of the joint housing 1, the static seal can further improve the sealing effect of the two.

[0090] In the implementation of the present disclosure, while the sealing end cover 13 realizes the sealing function of the other end of the joint housing 1, it can also limit the motor stator 51. Moreover, the sealing end cover 13 and the joint output end cover 14 achieve the waterproof sealing of the axial two ends of the harmonic joint, fully ensuring the isolation effect between the inside and outside of the harmonic joint with a hollow structure.

[0091] In the embodiment of the present disclosure, in combination with Figure 5 For further detailed description, one end of the wire passing cylinder 6 further protrudes to form a socket portion 63, and the sealing end cover 13 also has a socket edge 133 socketed to the socket portion 63. The sealing end cover 13 can thus form a circuit board installation cavity on the side facing the inside of the joint housing 1 for hermetically installing the drive circuit board in the drive assembly 5. While improving the utilization rate of the internal space of the harmonic joint, it can also waterproof and seal the drive circuit board, enabling the harmonic joint to be better applied to wading or humid scenarios.

[0092] The specific setting method of the above-mentioned sealing end cover 13 can not only realize the covering and sealing of one end of the first limiting portion 12, but also block and limit the other side of the motor stator 51 through the insertion and pressing action of the sealing edge 131, and also has the function of "one component for multiple uses", and can also reduce the assembly parts of the harmonic joint to a certain extent and improve the assembly compactness.

[0093] In an alternative embodiment, the flexspline 3 is provided with a torque sensor 31.

[0094] Optionally, in combination with Figure 3For further detailed description, the torque sensor 31 can be, for example, a strain gauge, and multiple strain gauges are uniformly and alternately attached to the circumferential surface of the flexspline 3 at intervals. In this way, when the flexspline 3 rotates, its own rotational speed and deformation magnitude can act on the strain type torque sensor 31 correspondingly, and the strain type torque sensor 31 can correspondingly generate an electrical signal and transmit it to the circuit board. The torque sensor 31 can also adopt other known forms.

[0095] A torque sensor 31 is arranged in the flexspline 3 and is correspondingly electrically connected to the circuit board. In this way, there is no need to additionally install a torque sensor. On the premise of ensuring high-precision torque measurement, the number of parts can be reduced, the cost can be lowered, and the length of the dimension chain can be shortened.

[0096] In an alternative embodiment, the flexspline 3 includes a thin-walled cylinder 32, and the thin-walled cylinder 32 is provided with a temperature sensor 321 for detecting the internal temperature.

[0097] Optionally, in combination Figure 7 For further detailed description, the thin-walled cylinder 32 in the flexspline 3 can be specifically arranged to extend along the axial direction of the flexspline 3, and one or more temperature sensors 321 can be specifically arranged in the thin-walled cylinder 32. When multiple temperature sensors are arranged, they can be evenly spaced. In this way, the internal temperature rise of the harmonic joint can be monitored in real time through the temperature sensor 321, preventing the risk of permanent damage to the harmonic joint caused by excessive temperature rise of the harmonic joint, and also providing a basis for the replacement and filling of lubricating grease in the harmonic joint.

[0098] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present disclosure, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0099] The above is only the specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can easily think of changes or substitutions, which should all be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A harmonic joint, characterized in that: include: A joint housing (1), wherein one end of the inner peripheral wall of the joint housing (1) is provided with a first limiting ring groove (11); A reducer assembly, the reducer assembly being arranged in the joint housing (1), and comprising a rigid wheel (2) and a rolling body (24); Wherein, a second limiting ring groove (21) corresponding to the position of the first limiting ring groove (11) is arranged in the outer peripheral wall of the rigid wheel (2), and the second limiting ring groove (21) and the first limiting ring groove (11) form a limiting ring cavity (23); The rolling body (24) is arranged in the limiting ring cavity (23); the rolling body (24), the outer peripheral wall of the rigid wheel (2) and the outer peripheral wall of the joint housing (1) together form a rolling bearing structure.

2. The harmonic joint according to claim 1, wherein: The joint housing (1) further comprises a first limiting portion (12), and the first limiting portion (12) is arranged on the inner peripheral wall of the joint housing (1); The harmonic joint further comprises a driving assembly (5), wherein the driving assembly (5) is arranged in the joint housing (1) and is used to provide driving force for the reducer assembly; The driving assembly (5) comprises a motor stator (51), and the motor stator (51) is limited in the first limiting portion (12).

3. The harmonic joint according to claim 2, wherein: The joint housing (1) further comprises a second limiting portion (15), wherein the second limiting portion (15) is arranged on the inner peripheral wall of the joint housing (1) and is spaced apart from the first limiting portion (12); The reducer assembly also includes a flexible wheel (3), the flexible wheel (3) meshing with the inner gear ring of the rigid wheel (2), and the flexible wheel (3) is limited to the second limiting portion (15).

4. The harmonic joint according to claim 2, wherein: The harmonic joint further comprises a wire-passing barrel (6), wherein the wire-passing barrel (6) is axially arranged in the joint housing (1); The driving assembly (5) further comprises a motor shaft (53) and a motor rotor (52), wherein the motor shaft (53) is rotatably supported on the first part of the wire reel (6), and the motor rotor (52) is arranged on the motor shaft (53); The reducer assembly comprises a wave generator (4), the wave generator (4) is fixed to the motor shaft (53), and the wave generator (4) is rotatably supported on the second part of the wire reel (6).

5. The harmonic joint according to claim 4, wherein: The first part of the wire barrel (6) comprises a fixing column (64), wherein the fixing column has a positioning surface perpendicular to the axial direction; The driving assembly (5) further comprises a high-speed end encoder (8); The high-speed end encoder (8) comprises a high-speed end encoder circuit board and a high-speed end encoder code disc; The high-speed end encoder circuit board is fixed to the positioning surface of the fixing column (64), and the high-speed end encoder code disk is attached to the end surface of the motor shaft (53) opposite to the positioning surface of the fixing column (64).

6. The harmonic joint according to claim 4, wherein: The driving component (5) further comprises a low-speed end encoder; The low-speed end encoder comprises a low-speed end encoder code disc and a low-speed end encoder circuit board; The low-speed end encoder code disc is attached to the end face of the rigid wheel (2) close to the drive assembly (5), and the low-speed end encoder circuit board is radially fixed to the inner circumferential wall of the joint housing (1) and is opposite to the low-speed end encoder circuit board.

7. The harmonic joint according to claim 4, wherein: The harmonic joint comprises a joint output end cover (14), and the joint output end cover (14) is fixed to one end of the rigid wheel (2) close to the opening of the joint housing (1); The wire-passing barrel (6) passes through the joint output end cover (14), and a first dynamic seal (141) is provided between the wire-passing barrel (6) and the joint output end cover (14); A second dynamic seal (22) is provided between the inner peripheral wall of the joint housing (1) and the outer peripheral wall of the rigid wheel (2) at one end close to the opening of the joint housing (1), and the second dynamic seal (22) is used to seal and isolate the limiting ring cavity (23) from the external environment.

8. The harmonic joint according to claim 6, wherein: The harmonic joint comprises a sealing end cover (13), the sealing end cover (13) is fixed to one end of the joint housing (1) close to the driving assembly (5), and the wire barrel (6) passes through the sealing end cover (13); A circuit board installation cavity (132) is formed on one side of the sealing end cover (13) facing the interior of the joint housing (1); the driving component (5) further comprises a driving circuit board, which is arranged in the circuit board installation cavity (132).

9. The harmonic joint according to claim 3, wherein: The flexible wheel (3) is provided with a torque sensor (31).

10. The harmonic joint according to claim 3, wherein: The flexible wheel (3) comprises a thin-walled cylinder (32), and the thin-walled cylinder (32) is provided with a temperature sensor (321) for detecting the internal temperature.

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