A dual-motor coaxial integrated two-degree-of-freedom joint module that eliminates cable wear and a robot comprising the joint module

Abstract

The application discloses a double-motor coaxial integrated two-degree-of-freedom joint module for preventing cable abrasion and a robot comprising the joint module and belongs to the field of robot joint driving. The module comprises a segmented shell assembly and a built-in double-inner-rotor motor. The stator windings of the two motors are fixed to the stationary shell. All motor cables are led out through the shell wiring holes, and there is no relative rotation in the whole process, so that the cable torsion abrasion failure is eliminated from the bottom of the structure. The first motor is matched with a two-stage NGW planetary reduction mechanism, and a tubular first output member is output. The second motor adopts a double-planetary-wheel NN single-stage reduction mechanism, and a two-stage inner gear ring is used as a second output member. The first output member penetrates through the center of the second motor and the second transmission mechanism coaxially, and the two sets of output flanges are coplanar and flush, so that the offset bending moment is eliminated and the axial size is compressed. The double-path differential angle detection structure considers the joint output rigidity and motion positioning accuracy under the premise of high integration and small size, and is suitable for two-degree-of-freedom joints of various leg-foot robots.

Description

Technical Field

[0001] This invention relates to robot joint drive technology, specifically to a joint module for legged robots, and more particularly to a dual-motor integrated joint module that can eliminate cable torsional wear at the structural source, and a robot including the joint assembly. Background Technology

[0002] In legged robots (such as quadrupedal and bipedal robots), joints such as the hip joint need to output two sets of rotational degrees of freedom simultaneously to achieve thigh swinging and link pushing / pulling movements, respectively. The mainstream industry solution is to arrange two independent motor modules in series on a support frame: the first motor drives the thigh component, and the second motor is mounted on the thigh and drives the links. This series configuration has several unavoidable engineering drawbacks: High risk of cable fatigue damage: When the first motor drives the thigh and the second motor fixed to it to rotate together, the power supply and signal cables of the second motor will repeatedly twist and bend along with the second motor body. Under the conditions of high-frequency, large-angle movement of the robot, the copper wires inside the cable are very prone to breakage due to metal fatigue, and the insulation layer will also be damaged due to friction and compression. This can cause signal abnormalities and motor phase loss, or even sudden joint failure or robot fall. Although methods such as cable carriers, spiral cables, or reserved torsion allowances have been tried in engineering to alleviate the problem, these additional measures not only occupy valuable space and increase the inertia of the legs, but also have their own wear and tear life, and have not fundamentally solved the problem.

[0003] Furthermore, the traditional series structure results in a significant axial offset between the output faces of the two motors. The force application point of the thigh and the force application point of the connecting rod are not in the same plane, causing additional bending moments. This not only requires thicker and heavier structural components but also reduces transmission accuracy. At the same time, it is difficult to provide a continuous central wiring channel inside the series motor assembly, and the cables of the end effector or sensor must be routed externally, further increasing the risk of hook damage. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the purpose of this invention is to provide a coaxial integrated two-degree-of-freedom joint module for legged robots, which solves the technical defects of traditional serial motor solutions such as cable torsion wear, large axial dimensions, and lack of a central through-path for wiring.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a dual-motor coaxially integrated two-degree-of-freedom joint module that eliminates cable wear, including a housing assembly, and a first motor and a second motor both integrated inside the housing; the housing is a segmented structure, including at least a first housing, a second housing and a third housing arranged coaxially in sequence, and axially locked together by a through long screw; Both the first and second motors are internal rotor motors, and their stator windings are fixedly installed on the inner wall of the housing, so that all motor windings are completely stationary relative to the housing; all power supply and signal cables connected to the stator windings are led out from the side wall of the housing and remain stationary relative to the housing within the entire range of motion of the joint module, without participating in any rotational movement; the first, second, and third housings are all provided with wiring holes, which are interconnected to form a stationary lead wire channel for the cables to pass through; The stator winding of the first motor is fixed to the inner wall of the first housing; the rotor of the first motor is connected to the input end of the first transmission mechanism; the first transmission mechanism is a two-stage NGW planetary gear transmission, including a first-stage sun gear, a first-stage planetary gear, a first-stage internal gear ring fixed to the first housing, a first-stage planetary carrier, a second-stage sun gear, a second-stage planetary gear, a second-stage internal gear ring fixed to the first housing, and a second-stage planetary carrier; the first-stage planetary carrier and the second-stage sun gear are coaxially fixedly connected; the rotor of the first motor is connected to the first-stage sun gear; the second-stage planetary carrier extends to form a first output component; The stator winding of the second motor is fixed to the inner wall of the second housing, and the end face of the third housing abuts against the end face of the second housing, axially clamping and fixing the stator winding of the second motor; the rotor of the second motor is connected to the input end of the second transmission mechanism; the second transmission mechanism is an NN-type planetary transmission, including a planet carrier, a double planetary gear, a first-stage internal gear ring, and a second-stage internal gear ring; the planet carrier is connected to the rotor of the second motor, serving as the input end of the second transmission mechanism; the first-stage internal gear ring is fixed inside the third housing; the double planetary gear is rotatably supported on the planet carrier via a planetary gear shaft, and the double planetary gear has a first gear and a second gear that are coaxially fixed and have different numbers of teeth, the first gear meshing with the first-stage internal gear ring, and the second gear meshing with the second-stage internal gear ring; the second-stage internal gear ring serves as the second output component; The first output component coaxially passes through the rotor of the second motor and the central area of ​​the second transmission mechanism, and the output end face of the first output component and the output end face of the second output component are located on the same plane or are substantially flush. Furthermore, a first crossed roller bearing is provided between the second-stage internal gear ring of the first motor and the second housing. The outer ring of the first crossed roller bearing is axially clamped by the end face of the second-stage internal gear ring and the end face of the second housing. The inner ring of the first crossed roller bearing is connected to the outer circle of the second-stage planetary carrier and is pressed against the end face of the inner ring of the first crossed roller bearing by a bearing baffle fixed to the second-stage planetary carrier.

[0006] Furthermore, a washer and a second crossed roller bearing are provided between the primary internal gear ring and a right end cover; the end face of the primary internal gear ring abuts against one end face of the washer, the other end face of the washer abuts against the outer ring end face of the second crossed roller bearing, and the end face of the right end cover abuts against the other end face of the outer ring of the crossed roller bearing; the third housing clamps the outer ring of the crossed roller bearing with the right end cover via the washer and simultaneously restricts the axial movement of the primary internal gear ring; the inner ring of the crossed roller bearing is connected to the outer circle of the secondary internal gear ring, and the second output component is fixed to the end face of the secondary internal gear ring by screws and clamps the inner ring of the crossed roller bearing.

[0007] Furthermore, a first support bearing is provided between the inner hole of the second output component and the outer circle of the planetary carrier, and a second support bearing is provided between the inner hole of the second housing and the outer circle of the planetary carrier. The first support bearing and the second support bearing together constitute the double-support structure of the planetary carrier to withstand the axial force transmitted by the second rotor and ensure rotational accuracy.

[0008] Furthermore, a second drive board is installed in the annular space between the inner wall of the second housing and the outer wall of the first output component for driving the second motor; the cable of the second drive board is led out through the wiring hole on the housing and remains stationary relative to the housing.

[0009] Furthermore, a first drive plate is installed within the annular space of the left end cover for driving a first motor; the cable of the first drive plate remains stationary relative to the outer casing.

[0010] Furthermore, it also includes a first angle detection device and a second angle detection device; the first angle detection device includes a main detection wheel, a slave detection wheel, and a first drive plate. The main detection wheel is fixed on the rotor shaft of the first motor, the first drive plate is fixed on the left end cover, and the slave detection wheel is installed on the left end cover. The main detection wheel and the slave detection wheel have different numbers of teeth and detect the rotational position and angle of the first motor rotor by meshing or magnetic induction; the second angle detection device includes a magnetic ring and a reading head. The magnetic ring is installed on the left end of the planetary carrier of the second transmission mechanism, and the reading head is integrated into the second drive plate. The second drive plate is fixed in the annular space between the inner wall of the second housing and the outer wall of the first output component, so that the reading head is stationary relative to the second housing and directly reads the rotational position of the magnetic ring.

[0011] Furthermore, the difference in the number of teeth between the first and second gears of the double planetary gear is 1 to 4 teeth. Combined with the tooth number matching relationship of the first and second fixed internal gear rings, a large reduction ratio is achieved in the NN planetary transmission structure, which greatly reduces the number of transmission stages and axial length.

[0012] Furthermore, the first motor, the first transmission mechanism, the second motor, and the second transmission mechanism all have through holes at their centers, and all through holes are connected along the axis to form a hollow cable passage that allows external cables and pipes to pass through.

[0013] Secondly, the present invention also provides a robot comprising the aforementioned dual-motor coaxial integrated two-degree-of-freedom joint module that eliminates cable wear.

[0014] Furthermore, in the robot, the output end of the first output component is used to connect to the drive link, and the output end of the second output component is used to connect to the robot's thigh component. The force connection point between the drive link and the thigh component is located in the same radial plane perpendicular to the axis. Compared with the prior art, the core beneficial effects of the present invention are concentrated in the following aspects: 1. Permanently eliminate cable twisting and wear at the source: Because all stator windings of the first and second motors are fixed to a stationary segmented housing, and the drive board is also built into a stationary annular space, all motor and drive cables are led out from the wiring holes on the housing and remain permanently stationary. During any movement of the joint, no motor cable needs to twist, pull, or bend with the joint rotation. This completely eliminates the most common and fatal cable fatigue fracture and insulation wear failures in legged robot joints, significantly improving the long-term operational reliability of the joint and virtually eliminating cable-related maintenance.

[0015] 2. Compact structure and significantly reduced axial dimensions: Through ingenious arrangement, the output shaft of the first motor passes through the center of the second motor and the second transmission mechanism, making the two output end faces flush with the same radial plane. The first output component connects to the drive linkage, and the second output component connects to the thigh component. The hinge points of the drive linkage and the thigh component can be arranged on the same radial plane, eliminating offset bending moments. Simultaneously, a single set of crossed roller bearings replaces the traditional multiple sets of radial + thrust bearings, integrating the bearing capacity for radial force, axial force, and overturning moment. This achieves high support rigidity within a minimal axial installation space, shortening the overall axial length of the joint. This makes the joint thinner and lighter, providing a foundation for the lightweight design of the entire machine. 3. Through-hole cable routing channel: A continuous through-hole is formed in the center of the module, which can easily allow external cables, air pipes or liquid cooling pipes to pass through, facilitating the delivery of resources to end tools or other joints. Although the external wiring harness passing through this channel may rotate relative to the housing, the ample through-hole space provided by the joint itself allows for the installation of mature anti-torsion devices such as electric slip rings and helical buffer sections. Furthermore, since all motor cables are fixed, there will be no interference with rotating parts or increased risk of wear. 4. High integration and good transmission rigidity: The left side adopts a two-stage NGW transmission to meet the requirements of high torque and high rigidity; the right side uses a double planetary gear NN transmission to achieve a considerable reduction ratio in a single stage, and the second-stage internal gear ring directly serves as the output flange, which greatly simplifies the number of parts and improves the rigidity and precision of the module.

[0016] 5. Good assembly processability of segmented housing: The segmented housing is tightened by long screws, which facilitates the segmented positioning, clamping and fixing of internal parts (such as internal gear ring, bearing, winding) and the clamping force between the end cover and the housing is used to axially limit the bearing outer ring and gear ring. The structure is simple and the positioning is reliable. Attached Figure Description

[0017] Figure 1 This is an axial cross-sectional view of an embodiment of the joint module of the present invention, used as a schematic diagram of the overall component partitioning; Figure 2 This is a complete axial cross-sectional schematic diagram of an embodiment of the joint module of the present invention; Figure 3 A simplified diagram of the two-stage NGW planetary transmission principle of the first transmission mechanism; Figure 4 This is a simplified diagram of the transmission principle of the second transmission mechanism; Marked in the image: 10. Outer shell; 11. First outer shell; 12. Second outer shell; 13. Third outer shell; 14. Right end cover; 15. Left end cover; 16. Long screw; 17. Wiring hole. 20. First motor; 21. First stator winding; 22. First rotor; 23. First rotor shaft; 30. First transmission mechanism; 31. First-stage sun gear; 32. First-stage planetary gears; 33. First-stage internal gear ring; 34. First-stage planetary carrier, 35; Second-stage sun gear, 36; Second-stage planetary gears, 37; Second-stage internal gear ring, 38; Second-stage planetary gear... Star frame, 381, first output component, 39, bearing baffle; 40. Second motor; 41. Second stator winding; 42. Second rotor; 50. Second transmission mechanism; 51. Planetary carrier; 52. Double planetary gears; 521. First gear; 522. Second gear. 53. First-stage internal gear ring; 54. Second-stage internal gear ring; 541. Second output component; 61. First crossed roller bearing; 62. Second crossed roller bearing; 63. First support bearing; 64. Second support shaft. Support, 65, washer; 70. Second drive board; 81. Main detection wheel; 82. Slave detection wheel; 83. First drive plate; 84. Magnetic ring; 90. Hollow cable passage. Detailed Implementation

[0018] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] As described in the background section, there are shortcomings in the existing technology. In order to solve the above-mentioned technical problems, this invention proposes a dual-motor coaxial integrated two-degree-of-freedom joint module that eliminates cable wear, as well as a robot including the module.

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to more clearly illustrate how to achieve permanent stationarity of the cable and eliminate wear.

[0022] See Figure 1 and Figure 2 The joint module in this embodiment has a segmented outer shell 10, a first motor 20, a first transmission mechanism 30, a second motor 40, and a second transmission mechanism 50; The segmented housing assembly 10 includes a first housing 11, a second housing 12, a third housing 13, a left end cover 15, a right end cover 14, a long screw 16, and a wiring hole 17. The first motor 20 includes a first stator winding 21, a first rotor 22, and a first rotor shaft 23; The second motor 40 includes a second stator winding 41 and a second rotor 42; The first transmission mechanism 30 includes a first-stage sun gear 31, a first-stage planet gear 32, a first-stage internal gear ring 33, and a first-stage... Star carrier 34, second-stage sun gear 35, second-stage planet gear 36, second-stage internal gear ring 37, second-stage planet carrier 38, first output component 381, bearing baffle 39; The second transmission mechanism 50 includes a planet carrier 51, a double planetary gear 52, a first gear 521, a second gear 522, a first-stage internal gear ring 53, a second-stage internal gear ring 54, and a second output component 541. The connection relationships of the above components are as follows: The segmented housing assembly 10 includes a first housing 11, a second housing 12, a third housing 13, a left end cover 15, a right end cover 14, a long screw 16, and a wiring hole 17. The first housing 11, the second housing 12, and the third housing 13 are axially locked into a rigid whole by the through long screw 16. The segmented housing has good assembly processability and facilitates the segmented positioning, clamping, and fixing of internal parts (such as internal gear rings, bearings, and windings). At the same time, the clamping force between the left end cover 15, the right end cover 14, and the housing is used to axially limit the bearing outer ring and gear ring. The structure is simple and the positioning is reliable. The first stator winding 21 of the first motor 20 is fixed to the inner wall of the first housing 11 with glue, and its lead wires are led out through the wiring holes 17 on the side wall of the first housing 11. The second stator winding 41 of the second motor 40 is fixed to the inner wall of the second housing 12, and the end face of the third housing 13 abuts against the end face of the second housing 12, axially clamping the second stator winding 41; the lead wires of the second stator winding 41 are led out through the wiring holes 17 on the second housing 12. The second drive board 70, which integrates a reading head, is installed in the annular space between the second housing 12 and the first output component 381, and all its cables are also led out through the wiring holes 17. The wiring holes 17 on the first housing 11, the second housing 12, and the third housing 13 are interconnected, forming a continuous stationary lead wire channel. Throughout the entire range of motion of the joint module, the housing 10 and all the cables attached to it remain absolutely stationary, and there is no contact or relative movement between the cables and the rotating parts, physically eliminating torsion and wear.

[0023] The above solution permanently eliminates cable torsional wear at its source: Since all stator windings of the first motor 20 and the second motor 40 are fixed to the stationary first housing 11 and second housing 12, and the second drive plate 70 is also built into the stationary annular space, all motor and drive cables are led out from the wiring holes on the housings and remain permanently stationary. During any joint movement, no motor cable needs to twist, pull, or bend with the joint rotation. This completely eliminates the most common and fatal cable fatigue fractures and insulation wear failures in legged robot joints, significantly improving the long-term operational reliability of the joint and virtually eliminating cable-related maintenance. Furthermore, a through-hole hollow wiring channel is used: continuous through holes are formed in the center of the module, allowing external cables, air pipes, or liquid cooling lines to pass through easily, facilitating the delivery of resources to end tools or other joints. Although the external wiring harness passing through the channel may rotate relative to the housing, the ample through-hole space provided by the joint itself allows for the placement of mature anti-torsion devices such as electric slip rings and helical buffer sections. Furthermore, since all motor cables are fixed, there will be no interference with rotating parts or increased risk of wear. Furthermore, the first rotor 22 of the first motor 20 is rotatably supported, and its rotor shaft 23 is connected to the first stage sun gear 31 of the first transmission mechanism 30. The first transmission mechanism 30 is a two-stage NGW planetary transmission: the first stage sun gear 31 meshes with the first stage planet gear 32, the first stage planet gear 32 simultaneously meshes with the first stage internal gear ring 33 fixed to the first housing 11, the first stage planet carrier 34 drives the second stage sun gear 35 through splines, the second stage sun gear 35 drives the second stage planet gear 36, the second stage planet gear 36 meshes with the second stage internal gear ring 37 fixed to the first housing 11, and the second stage planet carrier 38 extends to the right as a long tubular first output component 381.

[0024] Furthermore, the second rotor 42 of the second motor 40 is fixedly connected to the planetary carrier 51 of the second transmission mechanism 50. The second transmission mechanism 50 is an NN-type planetary transmission: a double planetary gear 52 is mounted on the planetary carrier 51; the double planetary gear 52 includes a first gear 521 and a second gear 522; the first gear 521 of the double planetary gear 52 meshes with a first-stage internal gear ring 53 fixed in the third housing 13, and the second gear 522 meshes with a second-stage internal gear ring 54; the first output component 381 passes integrally through the central hole of the second rotor 42, the central hole of the planetary carrier 51, and the inner hole of the second-stage internal gear ring 54 along the axis, and its right-end flange end face is precisely flush with the right-end flange end face of the second output component 541 on the same radial plane. Thus, the drive connecting rod can be fixed to the first output component 381, and the thigh component can be fixed to the second output component 541, and the connection hinge points of the two are coplanar, eliminating additional bending moment.

[0025] Furthermore, the difference in the number of teeth between the first gear 521 and the second gear 522 of the double planetary gear 52 is controlled to be 1 to 4 teeth. Combined with the tooth number matching relationship of the first and second fixed internal gear rings, a large reduction ratio can be achieved in the NN planetary transmission structure, which greatly reduces the number of transmission stages and axial length.

[0026] The above solution achieves a compact structure, significantly reducing axial dimensions: through clever arrangement, the output shaft of the first motor 20 passes through the center of the second motor 40 and the second transmission mechanism, making the two output end faces flush with the same radial plane. The first output component 381 connects to the drive linkage, and the second output component 541 connects to the thigh component. The hinge point between the drive linkage and the thigh component can be arranged on the same radial plane, eliminating offset bending moment. This makes the joint thinner and lighter overall, providing a foundation for lightweight design of the entire machine; at the same time, it has high integration and good transmission rigidity. Furthermore, in this embodiment, the left side of the joint module adopts a two-stage NGW transmission to meet the requirements of high torque and high rigidity; the right side uses a double planetary gear NN transmission to achieve a considerable reduction ratio in a single stage, and the second-stage internal gear ring directly serves as the output flange, which greatly simplifies the number of parts, improves the rigidity and precision of the module, and has high overall integration and good transmission rigidity.

[0027] Furthermore, a first crossed roller bearing 61 is provided between the second-stage internal gear ring 37 of the first motor and the second housing 12. The outer ring of the first crossed roller bearing 61 is axially clamped by the right end face of the second-stage internal gear ring 37 and the left end face of the second housing 12, and its inner ring mates with the outer circle of the second-stage planetary carrier 38 and is axially pressed by the bearing baffle 39. This bearing simultaneously bears the radial force, axial force, and overturning moment transmitted from the second-stage planetary carrier 38 within an extremely thin axial space; that is, a single set of first crossed roller bearings 61 replaces the traditional multiple sets of radial + thrust combined bearings, integrating the bearing of radial force, axial force, and overturning moment, achieving high support rigidity within a very small axial installation space, and shortening the overall axial length of the joint.

[0028] Furthermore, the right end face of the first-stage internal gear ring 53 abuts against the left end face of the washer ring 65, the right end face of the washer ring 65 abuts against the left end face of the outer ring of the second crossed roller bearing 62, and the left end face of the right end cap 14 abuts against the right end face of the outer ring.

[0029] Furthermore, the third housing 13 transmits axial force to the outer ring of the second crossed roller bearing 62 through the first-stage internal gear ring 53 and the washer 65, and together with the right end cover 14, clamps the outer ring, while restricting the axial movement of the first-stage internal gear ring 53. The inner ring of the second crossed roller bearing 62 mates with the outer circle of the second-stage internal gear ring 54, and the second output component 541 is fixed to the right end face of the second-stage internal gear ring 54 by screws, clamping the inner ring of the bearing. Thus, the second output component 541 connecting the thigh component obtains extremely high anti-overturning rigidity support; by using a single set of second crossed roller bearings 62 to replace the traditional multiple sets of radial + thrust combined bearings, it integrates the bearings to withstand radial force, axial force and overturning moment, achieving high support rigidity within a very small axial installation space and shortening the overall axial length of the joint.

[0030] Furthermore, the planetary carrier 51 is supported by a double-support structure: a first support bearing 63 is provided between the inner hole of the second output component 541 and the outer circle of the planetary carrier 51, and a second support bearing 64 is provided between the inner hole of the second housing 12 and the outer circle of the planetary carrier 51. The two bearings jointly bear the axial force of the second rotor 42, preventing rotor movement and ensuring the meshing accuracy of the NN transmission.

[0031] An auxiliary support bearing is provided between the outer wall of the first output component 381 and the inner hole of the planetary carrier 51 to provide radial support for the long tubular first output component 381 and reduce the flexural deformation under long span.

[0032] Furthermore, this embodiment also discloses an angle detection device for the first motor, namely, it further includes a first angle detection device, which includes a main detection wheel 81, a slave detection wheel 82, and a first drive plate 83. The main detection wheel 81 is fixed on the rotor shaft 23 of the first motor, and the slave detection wheel 82 is independently and rotatably mounted on the left end cover 15 through bearings and meshes with the main detection wheel 81. The first drive plate 83 is fixed on the left end cover. The main detection wheel 81 and the slave detection wheel 82 have different numbers of teeth. The rotational position and angle of the first motor rotor are detected by meshing or magnetic induction. The first drive plate 83 is completely stationary, and its signal line is led out from the wiring hole 17.

[0033] Furthermore, this embodiment also discloses a second motor angle detection device, namely, it further includes a second angle detection device, which includes a magnetic ring 84 and a reading head. The magnetic ring is installed at the left end of the planetary carrier 51 of the second transmission mechanism, and the reading head is integrated on the second drive plate 70. The second drive plate 70 is fixed in the annular space between the inner wall of the second housing 12 and the outer wall of the first output component 381, so that the reading head is stationary relative to the second housing 12, and the rotational position of the magnetic ring 84 is directly read. All circuit boards and cables of the two sets of sensing devices do not move relative to each other.

[0034] Furthermore, the center of the left end cover 15, the first rotor shaft 23, the first stage sun gear 31, the first stage planetary carrier 34, the second stage sun gear 35, the second stage planetary carrier 38 (i.e. the first output component 381), the planetary carrier 51, and the inner hole of the right end cover 14 are all designed as through holes, which are connected to form a hollow wire passage 90, allowing wire harnesses, air pipes, etc. to pass through to the end effector.

[0035] Furthermore, this embodiment also provides a robot that includes the aforementioned dual-motor coaxial integrated two-degree-of-freedom joint module that eliminates cable wear; therefore, this robot also possesses all the advantages described above. In some embodiments, the robot provided by this invention can be a legged robot, specifically including quadruped robots, bipedal robots, etc.

[0036] Furthermore, in the robot, the output end of the first output component 381 is used to connect to the drive link, and the output end of the second output component 541 is used to connect to the robot's thigh component. The force connection point of the drive link and the thigh component is located in the same plane perpendicular to the axis.

[0037] Finally, it should be noted that relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual-motor coaxial integrated two-degree-of-freedom joint module that eliminates cable wear, comprising a housing (10), and a first motor (20) and a second motor (40) both integrated inside the housing (10), characterized in that: The outer casing (10) is a segmented structure, comprising at least a first outer casing (11), a second outer casing (12), and a third outer casing (13) arranged coaxially in sequence, and axially locked together by a through long screw (16); each of the first outer casing (11), the second outer casing (12), and the third outer casing (13) is provided with interconnected wiring holes (17); the first motor (20) and the second motor (40) are both internal rotor motors, the first stator winding (21) is fixed to the inner wall of the first outer casing (11), and the second stator winding (41) is fixed to the inner wall of the second outer casing (12) and axially clamped by the end face of the third outer casing (13); all cables connected to the stator windings are led out from the wiring holes (17) and remain stationary relative to the outer casing (10) within the entire range of motion of the joint module; the rotor of the first motor (20) is connected to the first transmission mechanism (30). Input end; the first transmission mechanism (30) is a two-stage NGW planetary gear transmission, the first-stage internal gear ring (33) and the second-stage internal gear ring (37) are both fixed to the first housing (11), and the second-stage planetary carrier (38) extends to form the first output member (381); the rotor of the second motor (40) is connected to the input end of the second transmission mechanism (50); the second transmission mechanism (50) is an NN-type planetary transmission, including a first-stage internal gear ring (53) fixed in the third housing (13), a planetary carrier (51) equipped with double planetary gears (52) and a second-stage internal gear ring (54) as the second output member (541); the first output member (381) coaxially passes through the rotor of the second motor (40) and the center of the second transmission mechanism (50), and the output end face of the first output member (381) and the output end face of the second output member (541) are located on the same plane.

2. The joint module according to claim 1, characterized in that, A first crossed roller bearing (61) is provided between the second-stage internal gear ring (37) and the second housing (12). The outer ring of the first crossed roller bearing (61) is axially clamped by the second-stage internal gear ring (37) and the second housing (12), and the inner ring is engaged with the outer circle of the second-stage planetary carrier (38) and axially pressed by the bearing baffle (39).

3. The joint module according to claim 1, characterized in that, The right end face of the first-stage internal gear ring (53), the washer (65), the outer ring of the second crossed roller bearing (62), and the right end cover (14) abut against each other in sequence. The third outer shell (13) clamps the outer ring of the second crossed roller bearing (62) together with the right end cover (14) through the abutment relationship, and restricts the axial movement of the first-stage internal gear ring (53). The inner ring of the second crossed roller bearing (62) fits with the outer circle of the second-stage internal gear ring (54). The second output component (541) is fixed to the second-stage internal gear ring (54) by screws and clamps the inner ring.

4. The joint module according to claim 1, characterized in that, A first support bearing (63) is provided between the inner hole of the second output component (541) and the outer circle of the planetary carrier (51), and a second support bearing (64) is provided between the inner hole of the second outer shell (12) and the outer circle of the planetary carrier (51). The two bearings together constitute the double-support structure of the planetary carrier (51).

5. The joint module according to claim 1, characterized in that, A second drive plate (70) is installed in the annular space between the inner wall of the second housing (12) and the outer wall of the first output component (381). The second drive plate (70) integrates a reading head for detecting the position of the second motor rotor. The cable of the second drive plate (70) is led out from the wiring hole (17).

6. The joint module according to claim 1, characterized in that, It also includes a first angle detection device; the first angle detection device includes a main detection wheel (81) fixed on the rotor shaft (23) of the first motor, a slave detection wheel (82) rotatably mounted on the left end cover (15) via a bearing, and a first drive plate (83) fixed on the left end cover (15); the slave detection wheel (82) cooperates with the main detection wheel (81), and the main detection wheel (81) and the slave detection wheel (82) have different numbers of teeth; the first drive plate (83) is provided with a sensor for reading the rotation angle of the slave detection wheel (82).

7. The joint module according to claim 1, characterized in that, It also includes a second angle detection device, which includes a magnetic ring (84) mounted on the left end of the planetary carrier (51) and a reading head integrated on the second drive plate (70).

8. The joint module according to any one of claims 1 to 6, characterized in that, The first motor (20), the first transmission mechanism (30), the second motor (40) and the second transmission mechanism (50) are all provided with through holes in their centers and are interconnected to form a hollow wire passage (90).

9. A robot, characterized in that, Includes the joint module described in any one of claims 1-8.

10. The robot according to claim 9, characterized in that, The output end of the first output component (381) is used to connect the drive link, and the output end of the second output component (541) is used to connect the robot thigh component. The force connection point between the drive link and the thigh component is located in the same radial plane perpendicular to the axis.

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