Joint driving device

Abstract

The invention relates to the field of machinery, and discloses a joint driving device which comprises an output gear used for rotationally outputting power, a shifting fork structure, a first driving unit, a second driving unit and a shell assembly. The shifting fork structure is provided with a first connecting structure arranged in the axial direction and a second connecting structure arranged in the radial direction. The first driving unit is connected to the first connecting structure; and the second driving unit is mounted on the second connecting structure and is connected with the output teeth. Dual power output combination of the output teeth is achieved, redundant design is reduced, cost and complexity are reduced, and the whole joint driving device is simpler; the multi-degree-of-freedom output is realized in a smaller volume, and the space capability is optimized; axial rotation and radial rotation of the output teeth are independent, power output does not interfere with each other, accurate control over the shifting fork structure and the output teeth is achieved, reliable output is achieved according to needs, and motion control accuracy is improved. The structure is simplified to a certain extent, and mechanical abrasion and maintenance cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of mechanics, and in particular to a joint drive device. Background Technology

[0002] With the rapid development of humanoid robots in service, medical, and industrial fields, the performance requirements for robot joint modules are increasing, especially in terms of range of motion, precision, integration, and structural compactness. Existing robot joint modules mostly fall into two categories: rotary joint modules and linear joint modules. While each structure has its advantages and disadvantages, both still have limitations in achieving complex and precise human-like bionic movements.

[0003] Rotary joint modules are typically combined with motors via reducers (such as planetary reducers or harmonic reducers) to provide high torque output, meeting the high load and torque requirements of robots. However, they usually only have a single rotational degree of freedom, meaning a joint can only rotate around a fixed axis. To simulate complex joint movements with multiple degrees of freedom, at least two rotary joint modules are usually used in series. This is especially true when simulating ball-and-socket joints with multiple degrees of freedom, such as the shoulder and hip joints. In such cases, it is difficult to balance the range of motion and accuracy, making the integration of multi-degree-of-freedom drives a challenging problem. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a joint driving device to solve the problem that existing joint modules cannot integrate multi-degree-of-freedom driving.

[0005] To solve the above-mentioned technical problems, the present invention provides a joint drive device comprising an output tooth for rotating and outputting power, a shift fork structure, a first drive unit, a second drive unit, and a housing assembly; the shift fork structure has a first connecting structure arranged axially and a second connecting structure arranged radially; the first drive unit is axially connected to the first connecting structure and is used to drive the shift fork structure to rotate about the axial axis; the second drive unit is radially mounted on the second connecting structure and connected to the output tooth, and the second drive unit is used to drive the output tooth to rotate about the radial axis; the housing assembly is used to position the shift fork structure and the first drive unit within it.

[0006] Furthermore, the shift fork structure includes a base and two transmission arms connected to the base; the first connection structure has a first connection surface formed on the outer peripheral wall of the base for connecting the first drive unit to the base and an abutment surface formed on the outer peripheral wall of the base for the first drive unit to abut against it axially.

[0007] Furthermore, the base has a first end face, the two transmission arms are symmetrically disposed on the first end face, the first connecting surface extends axially to the first end face, and the first driving unit has a connecting side that is fitted onto the first connecting surface and abuts against the abutting surface, and a surrounding side that is spaced axially around the outer periphery of the two transmission arms.

[0008] Furthermore, the first drive unit includes a first rotor mounted on the first connecting surface and abutting against the abutting surface, and a first stator connected to the housing assembly. The first rotor is equipped with a first magnetic encoder and a first magnetic ring. A stepped surface is formed on the base to separate the transmission arm and the first rotor.

[0009] Furthermore, the housing assembly includes a housing rotatably mounted on the outer periphery of the first rotor and a rear cover rotatably mounted on the outer periphery of the first rotor and coaxially connected to the housing. The housing has an output port for some output teeth to extend out. A first bearing is provided between the housing and the first rotor to allow the first rotor to rotate relative to the housing. A second bearing is provided between the rear cover and the first rotor to allow the first rotor to rotate relative to the rear cover. A preload space is provided between the second bearing, the first rotor, and the rear cover. The housing assembly also includes a spring located in the preload space and elastically abutting against the second bearing and the rear cover along the axial direction. The spring is configured as a wave spring.

[0010] Furthermore, the second connection structure includes second connection surfaces formed on opposite sides of the two transmission arms, and connection holes formed on each second connection surface for connecting the second drive unit to the second connection surface via a connector.

[0011] Furthermore, the second drive unit includes a fixed base with its two ends respectively connected to two second connecting surfaces, a second stator fitted on the fixed base, a second rotor movably surrounding the second stator, and a second magnetic encoder mounted on the transmission arm. The output teeth are connected to the second rotor and rotatably fitted on the outer periphery of the fixed base. The fixed base includes a first end plate connected to one of the transmission arms, a central shaft coaxially connected to the first end plate and having a diameter smaller than the first end plate, and a second end plate detachably connected to the end of the central shaft away from the first end plate and connected to the other transmission arm. The second stator is mounted on the central shaft. Both the first end plate and the second end plate have protrusions for mounting a third bearing. A third bearing is provided between the output tooth and the protrusions to allow the third rotor and the output tooth to rotate relative to the fixed base.

[0012] Furthermore, the joint drive device of the present invention also includes a wiring channel and a conductive slip ring coaxially connected to the housing assembly; the wiring channel includes a first channel formed in the fixed base to communicate with the second stator, a second channel formed on the transmission arm and communicating with the first channel, and a third channel formed in the base and communicating with the second channel and the conductive slip ring.

[0013] Furthermore, the second channel includes a first channel formed on the transfer arm and located in the middle of the first connecting structure, the first channel radially penetrating the transfer arm along the base to connect the first channel; the second channel also includes a second channel formed on the transfer arm and connecting the first channel and the third channel, the second channel radially outward penetrating the transfer arm along the base; both transfer arms have symmetrically distributed second channels, and one of the transfer arms has an intersecting mounting groove that connects to the second channel, the mounting groove penetrating the second connecting surface; the third channel includes a third channel that connects the two second channels respectively and a channel opening located at the center of the base and axially penetrating the base to connect the conductive slip ring.

[0014] Furthermore, the outer wall of the output tooth is formed with strip teeth distributed circumferentially for meshing and coupling output power, and ring teeth formed on one side of the outer wall of the output tooth for meshing and sliding output engagement.

[0015] The joint drive device of the present invention has at least the following beneficial effects: by forming a first connecting structure and a second connecting structure on the shift fork structure, the first drive unit can drive the shift fork structure, the second drive unit on the shift fork structure, and the output teeth connected to the second drive unit to rotate around the axial axis after being connected to the first connecting structure; the second drive unit is integrated on the shift fork structure and drives the output teeth to rotate around the radial axis, thereby realizing the combination of dual power output of the output teeth, reducing redundant design and reducing cost and complexity to a certain extent, making the entire joint drive device simpler; multi-degree-of-freedom output is achieved in a smaller volume, and space capability is optimized; the axial rotation and radial rotation of the output teeth are independent, so that the power output does not interfere with each other, achieving precise control of the shift fork structure and the output teeth, achieving reliable output as needed, and improving motion control accuracy; the simplification of the structure to a certain extent reduces mechanical wear and maintenance costs. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of a structure of an embodiment of the joint driving device of the present invention; Figure 2This is a schematic diagram of a joint driving device according to an embodiment of the present invention. The diagram shows the three-dimensional structure of the joint driving device after one-quarter of it has been cut off. Figure 3 This is a side sectional view of an embodiment of the joint driving device of the present invention; Figure 4 This is a top sectional view of an embodiment of the joint driving device of the present invention; Figure 5 This is an exploded view of an embodiment of the joint drive device of the present invention, showing a perspective view of the second drive unit, shift fork structure and output teeth of the joint drive device in the assembled state. Figure 6 This is a schematic diagram of the fork structure in one embodiment of the joint driving device of the present invention; Figure 7 This is a half-sectional schematic diagram of the fork structure in one embodiment of the joint driving device of the present invention; Figure 8 This is a top sectional view of the fork structure in one embodiment of the joint drive device of the present invention; Figure 9 This is a half-sectional schematic diagram of the fork structure and the first drive unit in one embodiment of the joint drive device of the present invention. Figure 10 This is a side sectional view of the fork structure, the first drive unit, and the housing assembly in one embodiment of the joint drive device of the present invention. Figure 11 This is an exploded cross-sectional view of the housing assembly in one embodiment of the joint drive device of the present invention; Figure 12 This is a top sectional view of the fork structure, output teeth, and second drive unit in one embodiment of the joint drive device of the present invention. Figure 13 This is an exploded view of the second drive unit and the output tooth in one embodiment of the joint drive device of the present invention; Figure 14 This is a schematic diagram of the output tooth structure in one embodiment of the joint drive device of the present invention. The meanings of the labels in the attached diagram are as follows: Shift fork structure 1, base 11, first end face 111, second end face 112, first annular protrusion 113, stepped surface 114, transmission arm 12, clearance surface 121, first connecting structure 13, first connecting surface 131, abutting surface 132, second connecting structure 14, second connecting surface 141, connecting hole 142, wide section 1421, narrow section 1422, connector 15, first drive unit 2, first rotor 21, first end 21a, second end 21b, first surrounding section 211, middle section 212, second surrounding section 213, ladder 21c, first stator 22, first magnetic encoder 23, first magnetic ring 24, housing assembly 3, housing 31, output port 311, first slot 312, second slot 313, rear cover 32, ... The components are: a third groove 321, a fourth groove 322, a first groove surface 3221, a second groove surface 3222, a spring 33, a first bearing 34, a second bearing 35, a second drive unit 4, a fixed base 41, a first end plate 411, a central shaft 412, a second end plate 413, a protrusion 414, a second stator 42, a second rotor 43, a second magnetic encoder 44, a second magnetic ring 45, a third bearing 46, an output tooth 5, a strip tooth 51, a ring tooth 52, a tooth protrusion 521, an annular tooth 522, a wiring channel 6, a first channel 61, a branch 611, a second channel 62, a first channel 621, a second channel 622, a third channel 63, a third channel 631, a channel opening 632, a mounting groove 64, a connecting hole 641, and a conductive slip ring 7. Detailed Implementation

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Please see Figures 1 to 5The joint drive device of the present invention includes a shift fork structure 1, a first drive unit 2, a housing assembly 3, a second drive unit 4, an output tooth 5, a wiring channel 6, and a conductive slip ring 7. The shift fork structure 1 provides connection support for the installation of the first drive unit 2 and the second drive unit 4, and highly integrates the first drive unit 2 and the second drive unit 4. The housing assembly 3 provides protective support for the entire joint drive device and is used to cooperate with the first drive unit 2 to position the shift fork structure 1 and the first drive unit 2, so that they are fixed within the housing assembly 3. Output tooth 5 is used for rotation to output power. The first drive unit 2 and the second drive unit 4 enable output tooth 5 to perform axial and radial rotation outputs, thus achieving a combination of dual power outputs from output tooth 5. This reduces redundant design and lowers costs and complexity to some extent, making the entire joint drive device simpler. It achieves multi-degree-of-freedom output within a smaller volume, optimizing space capabilities. The axial and radial rotations of output tooth 5 are independent, ensuring that power outputs do not interfere with each other. This allows for precise control of the shift fork structure 1 and output tooth 5, providing reliable output as needed and improving motion control accuracy. The simplified structure reduces mechanical wear and maintenance costs. Wiring channel 6 provides a rational layout for the wiring of the internal second drive unit 4, ensuring that all components operate as expected. The conductive slip ring 7 works in conjunction with wiring channel 6 to achieve a rational wiring layout.

[0019] Please see Figures 6 to 8 The shift fork structure 1 includes a base 11 and two transmission arms 12 connected to the base 11. The base 11 is used to provide support for the first drive unit 2 and the transmission arms 12. The transmission arms 12 cooperate with the base 11 to realize the integrated setup of the power equipment.

[0020] The base 11 can be configured as a block-shaped three-dimensional structure. In this embodiment, the base 11 can be configured as a cylinder. In another embodiment, the base 11 can also be configured as a cuboid or other geometric structures, but a relatively regular geometric shape such as a polygonal prism should be selected to facilitate mass production and make the installation between the base 11 and the first drive unit 2 easier. The center of the base 11 is selected as a reference to give it axial and radial directions distributed perpendicular to the axial direction, and the direction corresponding to the base 11 being rotated around the axial axis is defined as circumferential. The base 11 has a first end face 111 and a second end face 112 relatively distributed along the axial direction, and also has an outer peripheral wall distributed around the base 11 circumferentially.

[0021] The base 11 has a first connecting structure 13 for cooperating with the first driving unit 2. The first connecting structure 13, through its connection with the first driving unit 2, can drive the base 11 to rotate circumferentially and output power, thereby realizing the installation of the first driving unit 2 and the driving of the base 11 by the first driving unit 2. The first connecting structure 13 has a first connecting surface 131 formed on the base 11 and a supporting surface 132 formed on the base 11. The first driving unit 2 is axially fitted onto the first connecting surface 131 to be installed on the base 11, and after being installed on the base 11, the first driving unit 2 abuts against the supporting surface 132 axially to position the installation position of the first driving unit 2 and ensure that the first driving unit 2 can be installed in place.

[0022] In one embodiment, the first connecting surface 131 is formed circumferentially on the outer peripheral wall of the base 11. When the base 11 is cylindrical, the first connecting surface 131 can be annular. In another embodiment, when the base 11 is cuboid or cube-shaped, the first connecting surface 131 is cuboid or cube-shaped to match the contour of the base 11. To facilitate the installation of the first driving unit 2, the first connecting surface 131 is arranged to penetrate the first end face 111 of the base 11 along the axial direction. Correspondingly, the first driving unit 2 is provided with a hole structure that is consistent with or similar to the contour of the first connecting surface 131, so that the first driving unit 2 can be fitted onto the first connecting surface 131, i.e., onto the base 11, along the axial direction from the first end face 111 through the hole structure. Then, the connection is made by fixing means such as using glue, welding, bolts, or rivets.

[0023] In this embodiment, the abutting surface 132 and the first connecting surface 131 are arranged at a certain angle, such as an acute angle, a right angle, or an obtuse angle, so that after the first driving unit 2 is fitted onto the first connecting surface 131, one end face can abut against the abutting surface 132 axially. In one embodiment, the first connecting surface 131 can be connected to the abutting surface 132. For example, a first annular protrusion 113 is formed on the outer peripheral wall, protruding radially outward relative to the first connecting surface 131 along the base 11, and the first annular protrusion 113 is located close to the second end face 112 and away from the first end face 111. The first annular protrusion 113 can be distributed in a ring around the outer peripheral wall of the base 11 in the circumferential direction. The first annular protrusion 113 is also configured as several arc-shaped protrusions, and the several first annular protrusions 113 are evenly spaced around the outer peripheral wall of the base 11 in the circumferential direction. The first annular protrusion 113 is adjacent to and connected to the first connecting surface 131 on the side of the first end face 111 along the circumferential direction. The side of the first annular protrusion 113 adjacent to the first connecting surface 131 is configured as the abutment surface 132. In this embodiment, the first annular protrusion 113 can be formed by recessing around the outer peripheral wall of the base 11, or by protruding around the outer peripheral wall of the base 11. The first annular protrusion 113 can be integrally formed with the base 11, or it can be separately set from the base 11 and then connected by a fixed connection means, such as welding, bonding, or using anchors. The side of the first annular protrusion 113 facing away from the first connecting surface 131 can be flush with the second end face 112.

[0024] In another embodiment, the first connecting surface 131 and the abutting surface 132 are spaced apart. For example, after the first connecting surface 131 is formed on the outer peripheral arm of the base 11, a second annular protrusion (not shown in the figure) is circumferentially surrounding the outer peripheral wall of the base 11. The second annular protrusion has a conical surface connected to the first connecting surface 131 and in the shape of a frustum, and an abutting surface 132 connected to the conical surface and extending radially outward. The conical surface is arranged to gradually narrow near the first connecting surface 131 and gradually widen near the abutting surface 132, so that the conical surface can be used to wedge with the first driving unit 2.

[0025] Two transmission arms 12 are respectively disposed on the first end face 111, and the two transmission arms 12 are arranged symmetrically with respect to the center of the base 11. One end of the transmission arm 12 is integrally connected to the base 11 to ensure the strength of the entire shift fork structure 1, and the other end of the two transmission arms 12 extends axially toward the side away from the second end face 112. In order to prevent the transmission arms 12 from interfering with the first drive unit 2, a clearance surface 121 is formed on the opposite side of the two transmission arms 12, which is always spaced from the inner wall of the hole structure of the first drive unit 2, so that the rotation of the shift fork structure 1 can proceed smoothly. The clearance surface 121 may be arc-shaped, and the two clearance surfaces 121 are on the same circumference to ensure the symmetry of the two transmission arms 12. The diameter of the clearance surface 121 is smaller than the minimum inner diameter of the hole structure.

[0026] To better separate the clearance surface 121 from the hole structure, a stepped surface 114 is formed on the first end face 111 between the clearance surface 121 of the transfer arm 12 and the first connecting surface 131. The transfer arm 12 extends axially from the stepped surface 114 to separate the transfer arm 12 from the first connecting surface 131. The stepped surface 114 may be arc-shaped, with its inner arc edge (the radially inward side edge) on the same circumference as the clearance surface 121, to facilitate the machining of the stepped surface 114.

[0027] A second connecting structure 14 is also provided on the two transmission arms 12 for mounting the second drive unit 4. The second connecting structure 14 enables the second drive unit 4 to rotate radially and output power after operation, thereby achieving dual-axis dual-power output in combination with the rotation of the shift fork structure 1. At the same time, the first drive unit 2 and the second drive unit 4 are highly integrated on the shift fork structure 1 with a simple structure, which greatly saves installation space compared to using two independent actuators, making the overall structure more compact. It can also achieve the coordinated work of the two drive units, providing a larger combined torque or power for the same output task, so as to handle a larger load. The alternating use of dual-power equipment can also avoid the single-power equipment being in a high-load state for a certain period of time, which helps to extend the service life of the overall system and ultimately achieve multi-degree-of-freedom control and better dynamic response.

[0028] In one embodiment, the second connection structure 14 includes second connection surfaces 141 formed on opposite sides of the two transmission arms 12, and connection holes 142 formed on each second connection surface 141. The two second connection surfaces 141 are symmetrically arranged and have a space between them for the second drive unit 4 to be installed. Figure 11 Furthermore, the second drive unit 4 is radially distributed along the base 11, and its two ends are respectively connected to the two second connecting surfaces 141, so that the second connecting surfaces 141 provide connection support and arrangement space for the second drive unit 4.

[0029] The connecting holes 142 can be threaded holes and can be configured in at least two, such as four, arrangements. Each connecting hole 142 is distributed in a circular array to ensure uniform distribution. The second drive unit 4 can be fixed by creating through holes or threaded holes that fit the connecting holes 142, and using a connector 15, such as a screw, to sequentially screw the screw into the corresponding hole structures on the connecting holes 142 and the second drive unit 4. In this embodiment, each connecting hole 142 is arranged in a T-shape in the radial direction, having a wide section 1421 and a narrow section 1422. The wide section 1421 radially passes through the avoidance surface 121 to facilitate screw insertion into the connecting hole 142. During installation, the screw is screwed into the narrow section 1422 and the second drive unit 4, with the screw head located within the wide section 1421. The narrow section 1422 radially passes through the second connecting surface 141 so that the connecting hole 142 passes through the transmission arm 12, and the connector 15 can radially engage with the second drive unit 4.

[0030] It should be noted that the second drive unit 4 is equipped with bearing components, ensuring that the corresponding structure of the second drive unit 4 can rotate along the radial axis of the base 11 even when it is tightly connected to the second connecting surface 141. Furthermore, when the second drive unit 4 is installed between the two second connecting surfaces 141, there is a space between the two transmission arms 12 and the first end face 111 for the corresponding structure of the second drive unit 4 to rotate and be spaced apart. The side of the transmission arm 12 axially away from the base 11 is shorter than the second drive unit 4, allowing the rotating portion of the second drive unit 4 to extend out of the space between the two second connecting surfaces 141, enabling the second drive unit 4 to cooperate with other power equipment for power transmission output.

[0031] In another embodiment, the second connecting structure 14 (not shown in the figure) includes a movable block detachably connected to one of the transmission arms, a second connecting surface 141 formed on the other transmission arm 12, and a connecting hole 142 formed on the second connecting surface 141. A screw hole is radially formed along the base 11 on the other transmission arm 12 where the second connecting surface 141 is not provided, and the surface of the movable block is provided with an external thread screwed into the screw hole. A protrusion is formed on the movable block that protrudes radially along the base 11, and a recess is provided at the end of the second drive unit 4 for tenon-and-mortise engagement with the protrusion. The recess is rotatably connected to the end of the second drive unit 4 via a bearing. The end of the second drive unit 4 away from the recess is connected to the second connecting surface 141 through the engagement of the connector 15 and the connecting hole 142. During installation, after connecting one end of the second drive unit 4 to the second connecting surface 141, the protrusion is passed through the screw hole and tenon-and-mortise engaged with the recess, and the movable block is rotated until it is screwed into the screw hole, thereby achieving the connection between the second drive unit 4 and the shift fork structure 1.

[0032] Please see Figure 9The first drive unit 2 is mounted on the outer periphery of the shift fork structure 1 and is used to drive the shift fork structure 1 to rotate around the axial axis of the base 11. To make the fit between the first drive unit 2 and the shift fork structure 1 more rational, the first drive unit 2 has a connecting side mounted on the first connecting surface 131 and abutting against the abutting surface 132, and an enclosing side spaced axially around the two transmission arms 12 and the second drive unit 4. The connecting side enables the connection between the first drive unit 2 and the base 11 of the shift fork structure 1, and the transmission output of the first drive unit 2 to the shift fork structure 1 is achieved through the connection between the connecting side and the first connecting structure 13. The enclosing side allows the entire first drive unit 2 to enclose the transmission arms 12 and the second drive unit 4, effectively shortening the axial dimension of the entire joint drive device at the base 11 and achieving a highly integrated arrangement. Simultaneously, the first drive unit 2 can provide some protection for the second drive unit 4 between the transmission arms 12.

[0033] In this embodiment, the first drive unit 2 includes a first rotor 21 mounted on the first connecting surface 131 and abutting against the abutting surface 132, a first stator 22 connected to the housing assembly 3, a first magnetic encoder 23 mounted on the first rotor 21, and a first magnetic ring 24 surrounding the first rotor 21. When energized, the first rotor 21 and the first stator 22 generate a magnetic field that drives the first rotor 21 to rotate. The first magnetic ring 24 and the first magnetic encoder 23 cooperate with each other; the first magnetic ring 24 provides the first magnetic encoder 23 with information on changes in the magnetic field signal, and the first magnetic encoder 23 provides feedback signals to the controller, thus forming a complete closed-loop control system. It should be noted that the structure of the first drive unit 2 is not limited to the structure described in this embodiment; other power devices capable of driving the shift fork structure 1 can also be used, such as a rotary cylinder with an output shaft coaxially connected to the shift fork structure 1.

[0034] In this embodiment, the first rotor 21 has an internal space that is substantially consistent with the horizontal projection plane of the first connecting surface 131 along the axial direction. The internal space extends through both ends of the first rotor 21 along the axial direction, so that the first rotor 21 can be axially fitted onto the base 11 and fit against the first connecting surface 131. The two ends of the first rotor 21 are divided into a first end 21a and a second end 21b. After the first rotor 21 is fitted onto the first connecting surface 131, the first end 21a is parallel to and abuts against the abutting surface 132. For this purpose, the first end 21a is configured as the connecting side. The second end 21b is configured as the enclosure side and extends axially away from the base 11 after the first rotor 21 is fitted onto the base 11. The extended second end 21b covers the transfer arm 12 in its internal space. Due to the presence of the stepped surface 114, the transfer arm 12 is spaced apart from the inner wall of the first rotor 21, reducing interference and friction and improving the service life between the first rotor 21 and the transfer arm 12.

[0035] On the radially outward sidewall of the first rotor 21, i.e., the outer sidewall of the first rotor 21, a first surrounding section 211, a middle section 212, and a second surrounding section 213 are sequentially formed along the axial direction. Both the first surrounding section 211 and the second surrounding section 213 are stepped, gradually widening towards the middle section 212 along the axial direction. Both the first surrounding section 211 and the second surrounding section 213 have at least two layers of L-shaped stepped platforms 21c that are progressively larger than each other. The at least two layers of stepped platforms 21c are configured so that when other structures are installed on the outer sidewall of the first rotor 21, the corresponding structure is installed on the platform 21c closest to the end, so that the structure is spaced apart from the middle section 212 by the other layers of stepped platforms 21c. For example, the first surrounding section 211 has three layers of stepped platforms 21c, and the second surrounding section 213 has two layers of stepped platforms 21c. The middle section 212 is located at the point of greatest thickness of the first rotor 21 and is situated axially at the center of the first rotor 21. The first stator 22 surrounds the middle section 212, enabling the first rotor 21 to magnetically cut against the first stator 22 and generate a magnetic field. The first surrounding section 211 is positioned close to the first end 21a of the first rotor 21, and the second surrounding section 213 is positioned close to the second end 21b of the first rotor 21. It should be noted that the first magnetic encoder 23 has through holes through which the wiring of the first stator 22 passes axially.

[0036] To facilitate a reasonable distribution of the first magnetic ring 24, the first magnetic encoder 23, and other structures, the first surrounding section 211 has three stepped platforms 21c. The first magnetic ring 24 is fixedly fitted onto the stepped platform 21c located in the middle of the first surrounding section 211, so that the first magnetic ring 24 is spaced apart from the middle section 212. The first magnetic encoder 23 is movably fitted onto the outer periphery of the stepped platform 21c located in the middle of the first surrounding section 211, so that the first magnetic encoder 23 can better cooperate with the first magnetic ring 24.

[0037] Please see Figure 10 and Figure 11 The housing assembly 3 includes a housing 31 rotatably mounted on the outer periphery of the first rotor 21, a rear cover 32 rotatably mounted on the outer periphery of the first rotor 21 and coaxially connected to the housing 31, and a spring 33 formed between the rear cover 32 and the first rotor 21. The first stator 22 is fixedly connected to the housing 31 so that the first stator 22 and the housing assembly 3 remain stationary together, thereby allowing the first rotor 21 to rotate relative to the first stator 22 and the housing assembly 3.

[0038] The housing 31 can be cylindrical for easy machining, but it is not limited to a cylindrical structure and can be made into other shapes. The axial direction of the housing 31 is aligned with and coaxial with the axial direction of the base 11. One end of the housing 31 has an output port 311 for some of the output teeth 5 to extend out. The output port 311 can be circular and have a diameter larger than the maximum radial dimension between the two transmission arms 12, so that the transmission arms 12 can pass through the output port 311. The output teeth 5 on the second drive unit 4 located between the two transmission arms 12 can pass through the output port 311 and exit the housing 31.

[0039] A first bearing 34 is provided between the housing 31 and the first rotor 21 to allow the first rotor 21 to rotate relative to the housing 31. To facilitate the installation of the first bearing 34, a first groove 312 is recessed on the inner wall of the housing 31 at the position corresponding to the outermost step 21c of the second ring section 213. The first groove 312 is L-shaped and forms a first installation space adapted to the first bearing 34 with the step 21c on the second ring section 213. The inner ring of the first bearing 34 is connected and fitted onto the second ring section 213 through the step 21c. The groove wall of the first groove 312 is fixedly connected to the outer ring of the first bearing 34, thereby enabling the first rotor 21 to rotate relative to the housing 31. The housing 31 has a second groove 313 at the position corresponding to the middle section 212 of the first rotor 21, in which the first stator 22 is fixedly installed. The second groove 313 is stepped and deeper than the first groove 312, so that the thickness of the housing 31 corresponding to the first groove 312 is greater than the thickness of the housing 31 corresponding to the second groove 313. This makes the installation layers of the first bearing 34 and the first stator 22 clear, ensuring that the rotational fit between the housing 31 and the first rotor 21 and the fixed fit between the housing 31 and the first stator 22 are arranged in an orderly and reasonable manner. In terms of spatial layout, the housing 31, the first stator 22 and the first rotor 21 are reduced and concentrated in both the axial and radial directions, thereby effectively reducing the overall size.

[0040] Since the housing 31 is currently only connected to the second surrounding section 213 of the first rotor 21, there is no direct connection between the housing 31 and the first surrounding section 211 of the first rotor 21, i.e., between the housing 31 and the first end 21a of the first rotor 21. To improve the stability between the housing assembly 3 and the first rotor 21, and to block the first stator 22, a rear cover 32 is provided. The rear cover 32 can also be cylindrical and its outer diameter is consistent with the outer diameter of the housing 31. On the radially outward side of the rear cover 32, i.e., the outer wall of the rear cover 32 and the side close to the housing 31, a third groove 321 is recessed for the housing 31 to be placed on. The second groove 313 of the housing 31 extends axially away from the first groove 312 and through to the other end of the housing 31, so that the thickness of the end of the housing 31 is moderate and can be spliced ​​with the third groove 321. Then, the housing 31 and the rear cover 32 are fixedly connected by fixing means, such as welding or using anchors. The first magnetic encoder 23 can be connected to the rear cover 32 so that the first magnetic encoder 23 can be fixed in position relative to the housing assembly 3 and remain stationary. The inner side of the first magnetic encoder 23 is spaced apart from the first rotor 21. A second bearing 35 is provided between the rear cover 32 and the first rotor 21 to allow the first rotor 21 to rotate relative to the rear cover 32. To facilitate the installation of the second bearing 35, a fourth groove 322 is recessed on the rear cover 32. The fourth groove 322 has at least a first groove surface 3221 for radial connection to the outer ring of the second bearing 35. A stepped platform 21c of the first surrounding section 211, axially away from the middle section 212, is connected to the inner ring of the second bearing 35 so that the first rotor 21 can rotate relative to the rear cover 32. The rear cover 32 is connected to the housing 31 so that the entire housing assembly 3 and the first end 21a and the second end 21b of the first rotor 21 maintain rotational engagement and structural support, so that the housing assembly 3 and the first drive unit 2 maintain a stable assembly.

[0041] To reduce vibration, noise, and uneven prestress generated between the second bearing 35, the rear cover 32, and the first rotor 21 during the rotation of the first rotor 21, at least one second groove surface 3222 is provided on the fourth groove 322, which is adjacent to the first groove surface 3221 and forms an L-shape with the first groove surface 3221. The second groove surface 3222 is located on the side away from the housing 31 relative to the first groove surface 3221. When the second bearing 35 is installed, it can be supported against other ladders 21c along the axial direction toward the second end 21b. A pre-tightening space is provided between the second bearing 35, the first rotor 21, and the rear cover 32. That is, the pre-tightening space is formed by the first groove surface 3221, the second groove surface 3222, the second bearing 35, and the first surrounding section 211 of the first rotor 21. The spring 33 is installed axially in the pre-tightening space and elastically abuts against the second bearing 35 and the second groove surface 3222 along the axial direction, thereby elastically pre-tightening the rear cover 32, the second bearing 35, and the first rotor 21. During the rotation of the first rotor 21, the elastic preload of the spring 33 effectively absorbs and attenuates some of the vibration energy generated by the first rotor 21, preventing it from being transmitted outwards. The spring 33 can change the natural frequency of the system, avoiding resonance with external structures to a certain extent, thus improving the comfort and precision of the equipment. Furthermore, the elastic preload of the spring 33 can achieve adaptive spatial adjustment between the second bearing 35, the first rotor 21, and the rear cover 32 in the axial direction, thereby compensating for and mitigating assembly errors to a certain extent, reducing the off-center load and friction of the second bearing 35, and making the second bearing 35 operate more smoothly. In this embodiment, the spring 33 is a wave spring 33, which can provide a constant axial preload to the second bearing 35. Simultaneously, the wave spring 33 occupies a small space, providing preload and eliminating axial backlash while occupying only a small area, thus better achieving miniaturization of the joint drive device. It should be noted that the spring 33 should elastically abut against the outer ring of the second bearing 35.

[0042] Please see Figure 12 and Figure 13The second drive unit 4 includes a fixed base 41 with its two ends respectively connected to two second connecting surfaces 141, a second stator 42 fitted on the fixed base 41, a second rotor 43 movably surrounding the second stator 42, a second magnetic encoder 44 mounted on the transmission arm 12, and a second magnetic ring 45 connected to the output tooth 5. The output tooth 5 is connected to the second rotor 43 and rotatably fitted on the outer periphery of the fixed base 41, so that the second drive unit 4 is distributed with the arrangement direction of the two transmission arms 12, that is, the axial direction of the second drive unit 4 is radially distributed along the base 11. In this way, the second drive unit 4 can be installed inside the two transmission arms 12 and the first drive unit 2, thereby effectively shortening the axial dimension of the entire joint drive device. In another embodiment, the second drive unit 4 is disposed in the housing assembly 3. The second drive unit 4 includes a rotary cylinder and a gear connected to the output end of the rotary cylinder. The gear meshes with the output tooth 5 to drive the output tooth 5 to rotate.

[0043] The fixed base 41 includes a first end plate 411 connected to one of the transmission arms 12, a central shaft 412 coaxially connected to the first end plate 411 and having a smaller diameter than the first end plate 411, and a second end plate 413 detachably connected to the end of the central shaft 412 away from the first end plate 411 and connected to the other transmission arm 12. The first end plate 411 and the second end plate 413 cooperate with the second connecting structure 14 to achieve connection and fixation with the shift fork structure 1, while providing installation space for the second stator 42 and the second rotor 43 mounted on the central shaft 412, reducing the overall size of the second drive unit 4 while ensuring the power output of the output gear 5. Both the first end plate 411 and the second end plate 413 have a structure adapted to the second connecting surface 141, such as a cylindrical or polygonal prism structure. Both the first end plate 411 and the second end plate 413 have threaded grooves adapted to the connecting hole 142 for the connecting piece 15 to be screwed in. To facilitate the sequential mounting of the second stator 42, the second rotor 43, and the output gear 5 onto the central shaft 412, a second end plate 413 is detachably connected to the end of the central shaft 412 furthest from the first end plate 411. Threaded holes can be provided on both the second end plate 413 and the central shaft 412, allowing the second end plate 413 to be connected to the central shaft 412 using screws or rivets. During assembly, the second stator 42 is fitted onto the central shaft 412, and the second rotor 43 is movably positioned around the second stator 42, allowing it to rotate relative to it. The output gear 5 is fitted onto the second rotor 43.

[0044] To support the second rotor 43 and the output tooth 5, while ensuring the rotation of the output tooth 5 and the second rotor 43, each of the facing sides of the first end plate 411 and the second end plate 413 has a protruding portion 414 extending axially along the fixed base 41. The protruding portion 414 has a cylindrical structure and its diameter is smaller than the maximum diameter of the first end plate 411 and the second end plate 413. The protruding portion 414 is arranged coaxially with the central axis 412, so that a fifth annular groove is formed between the protruding portion 414 and the first end plate 411, and between the protruding portion 414 and the second end plate 413. A third bearing 46 is fitted in each of the two fifth grooves. The inner ring of the third bearing 46 is connected to the groove wall of the fifth groove to keep it stationary. In one embodiment, both ends of the second rotor 43 are respectively connected to the outer ring of the third bearing 46, and the output tooth 5 is directly fixed to the second rotor 43. In another embodiment, the second rotor 43 is spaced apart from the two second bearings 35, and the output tooth 5 is connected to the outer ring of the third bearing 46. In another embodiment, both the output tooth 5 and the second rotor 43 are connected to the outer ring of the third bearing 46. Regardless of the embodiment used, the output tooth 5 and the second rotor 43 are ultimately able to rotate relative to the output tooth 5 and the second stator 42 along the axis of the base 11, i.e., along the axial axis of the fixed base 41. It should be noted that the output tooth 5 is spaced between the transmission arm 12 and the first end face 111 to ensure that the output tooth 5 can rotate, but the gap between the output tooth 5 and the first end face 111 and the gap between the output tooth 5 and the transmission arm 12 should be as small as possible to reduce the overall volume, reduce the space ratio, and achieve miniaturization. The second magnetic encoder 44 is mounted on the transmission arm 12.

[0045] Please refer to 12 to Figure 14The output tooth 5 has a cylindrical structure with an axial dimension smaller than that of the fixed base 41. The interior of the output tooth 5 is axially connected to form a space for the second rotor 43 to pass through. On the outer wall of the output tooth 5, there are strip teeth 51 distributed circumferentially for meshing and coupling output power, and ring teeth 52 formed on one side of the outer wall for meshing and sliding output engagement. The strip teeth 51 are sequentially distributed circumferentially along the output tooth 5. When the output tooth 5 rotates circumferentially, the strip teeth 51 can drive the matching gear structure with the same function to rotate circumferentially (or in the opposite direction) along the output tooth 5 to achieve meshing. When the output tooth 5 rotates circumferentially along the base 11, that is, when the axial axis of the base 11 rotates, which is also the radial axis of the output tooth 5, the strip teeth 51 can drive the matching gear structure with the same function to rotate circumferentially along the base 11 to achieve coupling. The output tooth 5 can achieve dual-axis power output by rotating alternately or simultaneously along the circumference of the base 11 and its own circumference. The integration and / or state switching of two transmission modes can be achieved through one output tooth 5, which greatly simplifies the mechanical structure, reduces the number of parts, and is one of the key factors in realizing the miniaturization of the entire joint drive device. It also improves the system redundancy and reliability and achieves lightweighting.

[0046] The ring tooth 52, from the inside out, includes a toothed protrusion 521 and an annular tooth 522 surrounding the toothed protrusion 521. The annular tooth 522 has multiple rings. The strip tooth 51 adjacent to the ring tooth 52 gradually curves from straight to curved. The "straight" does not necessarily mean perfectly straight. When the ring tooth 52 meshes with other gear structures with the same structure, the operation of the first drive unit 2 will drive the output tooth 5 to rotate circumferentially along the base 11. At this time, the ring tooth 52 slides with the gear structure with the same structure without interfering with each other. This can be used to adjust the position of the output tooth 5 relative to other gear structures. When the second drive unit 4 is running, the ring tooth 52 can achieve the same function as the strip tooth 51 and mesh with other gear structures to drive them to rotate circumferentially along the output tooth 5. In this way, even with only one output tooth 5, it can be used for multi-axis rotation output, achieving multi-degree-of-freedom power output while ensuring a small number of parts.

[0047] Please see Figure 11 In this embodiment, in order to ensure that the wiring of the second drive unit 4 located between the two transmission arms 12 is not affected by the rotation of the shift fork structure 1, the wiring channel 6 is provided on the shift fork structure 1, so that after the second drive unit 4 is installed on the transmission arm 12, the wiring of the second drive unit 4 is arranged on the shift fork structure 1 through the wiring channel 6, so that the wiring of the second drive unit 4 can rotate with the shift fork structure 1.

[0048] The wiring channel 6 includes a first channel 61 formed within the mounting base 41 to connect to the second stator 42, a second channel 62 connecting to the space between the two transmission arms 12 and connecting to the first channel 61, and a third channel 63 formed within the base 11 and connecting to the second channel 62. The formation of the first channel 61 ensures that the wiring of the second drive unit 4 is distributed radially along the base 11, i.e., axially along the second drive unit 4, preventing the wiring of the second drive unit 4 from becoming entangled due to rotation of the corresponding structure. The second channel 62 allows the wiring of the second stator 42 and the second magnetic encoder 44 to be routed from the transmission arm 12, bypassing the space inside the transmission arm 12, preventing the wiring from interfering with the use of the output teeth 5. The third channel 63 allows all the wiring of each second drive unit 4 to converge on the base 11 for electrical connection to the circuitry.

[0049] The first channel 61 runs axially from the center of the fixed base 41 through the central shaft 412, the first end plate 411 and the second end plate 413. A branch 611 is radially opened on the protrusion 414 of the first end plate 411, which runs outward through the fixed base 41. The branch 611 connects to the first channel 61 so that the wiring on the second stator 42 enters the main body of the first channel 61 through the branch 611 and finally passes through the second channel 62 and the third channel 63. In this way, when the second rotor 43 and the output tooth 5 rotate, the wiring on the second stator 42 will not be affected at all, ensuring the safe use of the entire joint drive device.

[0050] The second channel 62 includes a first channel 621 formed on the transfer arm 12 and located in the middle of the first connecting structure 13, and a second channel 622 opened on the transfer arm 12 and connecting the first channel 621 and the second channel 62.

[0051] The first channel 621 radially penetrates the transfer arm 12 along the base 11, that is, the first channel 621 radially penetrates the avoidance surface 121 and the second connecting surface 141 of the transfer arm 12, thereby connecting the first channel 621 to the first channel 61, and the wiring of the second stator 42 can pass into the first channel 621. The first channel 621 is located at the center of each connecting hole 142 and is arranged coaxially with the first channel 61, thereby ensuring the orderly arrangement of the wiring of the second stator 42.

[0052] The second channel 622 extends radially outward from the base 11 through the clearance surface 121 of the transfer arm 12. Specifically, the second channel 622 is recessed relative to the clearance surface 121 at its central position. The second channel 622 also connects the first channel 621 and the third channel 63 axially along the base 11, allowing the wiring of the second stator 42 to be laid along the second channel 622 after passing through the first channel 621 until it enters the third channel 63. To ensure the basic strength of the transfer arm 12, the inward-facing side of the second channel 622 is closed. The outward-facing second channel 622 facilitates manual or mechanical pulling of the wiring within it, ensuring proper wiring layout while facilitating wiring installation. It should be noted that the depth of the second channel 622 should be greater than the overall width or diameter of the wiring to ensure the entire wiring is contained within it. When pulling the wiring, it should be ensured that it does not extend beyond the second channel 62. This can be achieved by straightening the wiring or by filling the second channel 62 with glue and allowing it to solidify before use.

[0053] In one embodiment, a second channel 62 is provided on one of the transmission arms 12, meaning that a first channel 621 and a second channel 622 are provided only on one transmission arm 12. In another embodiment, a first channel 621 and a second channel 622 are formed on both transmission arms 12, which are symmetrically distributed to allow the wiring to be laid out in two bundles, thus ensuring that the wiring does not extend beyond the second channel 62. A mounting groove 64 is provided on one of the transmission arms 12, intersecting and communicating with the second channel 622. The shape and size of the mounting groove 64 are adapted to the size of the second magnetic encoder 44, so that the second magnetic encoder 44 can be completely embedded in the mounting groove 64. A communicating hole 641 is provided in the mounting groove 64 radially inward along the base 11 to pass through the second connecting surface 141, thereby enabling the second magnetic encoder 44 to perform real-time closed-loop control of the operation of the second drive unit 4 and detect the real-time speed of the second rotor 43, etc. The mounting slot 64 can be opened only on the selected transmission arm 12, or it can be opened on both the transmission arm 12 and the base 11. The specific opening position is determined by factors such as the size of the second drive unit 4. The second magnetic ring 45 is fixedly fitted on the end of the output tooth 5 near the mounting slot 64 and is used in conjunction with the second magnetic encoder 44 through the connecting hole 641.

[0054] The third channel 63 includes a third channel 631 that connects the two second channels 622 respectively, and a channel opening 632 located at the center of the base 11 and extending axially through the base 11. The third channel 631 is radially opened along the base 11 and preferably extends through the outer peripheral wall of the base 11, so as to facilitate the insertion of the wiring from outside the base 11 from inside the second channel 622 into the third channel 631. The third channel 631 extends through the first connecting surface 131, and the third channel 631 may also partially extend through the first annular protrusion 113 to provide sufficient space for the third channel 631, and also to facilitate the wiring layout. In this embodiment, the two ends of the third channel 631 extending through the first connecting surface 131 extend axially along the base 11 through the second channel 622 and the mounting groove 64, thereby ensuring that the wiring of the second drive unit 4 can continue to extend from inside the second channel 622 and the mounting groove 64 into the third channel 631. The channel opening 632 is located at the center of the base 11 and its diameter or radial dimension is larger than that of the third channel 631, so that the channel opening 632 has sufficient space for the lines in the two first channels 61 to converge therein. After convergence, the lines pass through the channel opening 632 and exit axially along the base 11.

[0055] Please see Figure 3 , Figure 4 and Figure 10 The conductive slip ring 7 is coaxial with and connected to the rear cover 32. Multiple screw holes are correspondingly provided on both the conductive slip ring 7 and the rear cover 32, and screws are used to connect them. The outer diameter of the conductive slip ring 7 is consistent with the outer diameter of the housing 31 and the rear cover 32 to ensure the integrity of the joint drive unit. After the wiring in the wiring channel 6 exits through the channel opening 632, the wiring passes through the rotating part at the center of the conductive slip ring 7 to avoid tangling.

[0056] One embodiment of the joint drive device of the present invention operates as follows: First, after the third bearings 46 on the two first end plates 411 are installed, the second stator 42, the second rotor 43 and the output tooth 5 are installed in sequence. Then, the second drive unit 4 and the output tooth 5 are placed between the two second connecting surfaces 141. After the second drive unit 4 is fixed to the transmission arm 12 by the connector 15 through the connecting hole 142, the first channel 61 and the second channel 62 allow the wiring of the second drive unit 4 to be laid therein and converge into the third channel 63. Then, the first rotor 21 is mounted on the first connecting surface 131 along the axial direction of the base 11, and the abutment surface 132 restricts it. To complete the assembly of the first rotor 21, the first magnetic ring 24 and the second bearing 35 are sequentially mounted onto the first surrounding section 211. The first bearing 34 and the first stator 22 are then installed in the first groove 312 and the second groove 313. After the first magnetic encoder 23, the rear cover 32, and the conductive slip ring 7 are installed in sequence, the housing 31 and the rear cover 32 are finally connected and fixed, allowing the wiring of the second drive unit 4 to pass through the conductive slip ring 7. The wiring of the first drive unit 2 passes through the through hole on the first magnetic encoder 23, the hole structure opened on the rear cover 32 and the conductive slip ring 7, so that the second drive unit 4 and the housing assembly 3 surround the transmission arm 12, thus completing the integrated installation of the joint drive device.

[0057] Compared with the prior art, the joint drive device of the present invention, after the first drive unit 2 is installed on the first connecting structure 13, the first connecting surface 131 that runs through the first end face 111 along the axial direction allows the first drive unit 2 to be connected only part of the first connecting surface 131. The other side of the first drive unit 2 can extend and surround the transmission arm 12 to provide protection for the second drive unit 4 on the transmission arm 12. At the same time, the first drive unit 2 and the second drive unit 4 can be highly integrated to effectively reduce the size of the shift fork structure 1 and the entire joint drive device, thus miniaturizing the joint drive device. The arrangement of the wiring channel 6 allows the wiring of the second drive unit 4 located inside the first drive unit 2 to be laid out without obstruction, providing effective support for the high integration of the first drive unit 2 and the second drive unit 4.

Claims

1. A joint driving device, characterized in that, include: Output teeth, which are used to rotate and output power; A shift fork structure having a first connecting structure arranged axially and a second connecting structure arranged radially. The first driving unit is axially connected to the first connecting structure and is used to drive the shift fork structure to rotate around the axis of the axial direction. The second drive unit is radially mounted on the second connection structure and connected to the output tooth. The second drive unit is used to drive the output tooth to rotate about the radial axis. as well as A housing assembly for positioning the shift fork structure and the first drive unit therein.

2. The joint driving device as described in claim 1, characterized in that: The shift fork structure includes a base and two transmission arms connected to the base; the first connection structure has a first connection surface formed on the outer peripheral wall of the base for connecting the first drive unit to the base and an abutment surface formed on the outer peripheral wall of the base for the first drive unit to abut against it axially.

3. The joint driving device as described in claim 2, characterized in that: The base has a first end face, and the two transmission arms are symmetrically disposed on the first end face. The first connecting surface extends axially to the first end face. The first driving unit has a connecting side that is fitted onto the first connecting surface and abuts against the abutting surface, and a surrounding side that is spaced axially around the outer periphery of the two transmission arms.

4. The joint drive device as described in claim 2 or 3, characterized in that: The first drive unit includes a first rotor mounted on a first connecting surface and abutting against the abutting surface, and a first stator connected to the housing assembly. The first rotor is equipped with a first magnetic encoder and a first magnetic ring. A stepped surface is formed on the base to separate the transmission arm and the first rotor.

5. The joint driving device as described in claim 4, characterized in that: The housing assembly includes a housing rotatably mounted on the outer periphery of the first rotor and a rear cover rotatably mounted on the outer periphery of the first rotor and coaxially connected to the housing. The housing has an output port for some of the output teeth to extend out. A first bearing is provided between the housing and the first rotor to cause the first rotor to rotate relative to the housing. A second bearing is provided between the rear cover and the first rotor to cause the first rotor to rotate relative to the rear cover. A preload space is provided between the second bearing, the first rotor and the rear cover. The housing assembly also includes a spring located in the preload space and elastically abutting against the second bearing and the rear cover along the axial direction. The spring is configured as a wave spring.

6. The joint driving device as described in claim 2, characterized in that: The second connection structure includes second connection surfaces formed on opposite sides of the two transmission arms, and connection holes formed on each second connection surface for connecting the second drive unit to the second connection surface via a connector.

7. The joint driving device as described in claim 6, characterized in that: The second drive unit includes a fixed base with its two ends respectively connected to two second connecting surfaces, a second stator fitted on the fixed base, a second rotor movably surrounding the second stator, and a second magnetic encoder mounted on the transmission arm. The output teeth are connected to the second rotor and rotatably fitted on the outer periphery of the fixed base. The fixed base includes a first end plate connected to one of the transmission arms, a central shaft coaxially connected to the first end plate and having a diameter smaller than the first end plate, and a second end plate detachably connected to the end of the central shaft away from the first end plate and connected to the other transmission arm. The second stator is mounted on the central shaft. Both the first end plate and the second end plate have protrusions. A third bearing is provided between the output teeth and the protrusions to allow the third rotor and the output teeth to rotate relative to the fixed base.

8. The joint driving device as described in claim 6, characterized in that: It also includes wiring channels and conductive slip rings coaxially connected to the housing assembly; The wiring channel includes a first channel formed in the fixed base to connect to the second stator, a second channel formed on the transfer arm and connecting to the first channel, and a third channel formed in the base and connecting the second channel to the conductive slip ring.

9. The joint driving device as described in claim 8, characterized in that: The second channel includes a first channel formed on the transfer arm and located in the middle of the first connecting structure, the first channel extending radially through the transfer arm along the base to connect the first channel; The second channel also includes a second channel formed on the transfer arm and connecting the first channel and the third channel, the second channel extending radially outward through the transfer arm from the base; Both of the aforementioned transfer arms have symmetrically distributed second channels, and one of the transfer arms has an intersecting mounting groove that communicates with the second channel, the mounting groove penetrating the second connecting surface; The third channel includes a third channel that connects the two second channels respectively, and a channel opening located at the center of the base and extending axially through the base to connect the conductive slip ring.

10. The joint driving device as claimed in claim 1, characterized in that: The outer wall of the output tooth has strip teeth distributed circumferentially for meshing and coupling output power, and ring teeth formed on one side of the outer wall of the output tooth for meshing and sliding output engagement.

Images