Harmonic speed reduction module for humanoid robot dexterous hand joint

Abstract

The utility model provides a harmonic speed reduction module for a dexterous hand joint of a humanoid robot, and relates to the technical field of humanoid finger joints, the harmonic speed reduction module comprises an axial magnetic flux motor and a double-rigid-wheel harmonic speed reducer, the axial magnetic flux motor comprises a motor shell, an input shaft, a permanent magnet rotor and two PCB stators; the double-rigid-gear harmonic speed reducer comprises a wave generator, a flexible bearing, a flexible gear, a first rigid gear, a second rigid gear and a supporting bearing, the input shaft is fixedly connected with the wave generator, the first rigid gear serves as an inner ring of the supporting bearing and is detachably and fixedly connected with the motor shell, and a connecting plate is arranged between the first rigid gear and the motor shell; the rigid gear II is positioned on one side of the rigid gear I far away from the motor shell as a support bearing outer ring; the flexible bearings comprise two first flexible bearings which are arranged in parallel in the axial direction of the input shaft, and a limiting protrusion located between outer rings of the two first bearings is arranged in the middle of the inner wall of the flexible gear; an end cover is arranged on the side, away from the first rigid wheel, of the second rigid wheel. The axial length of the joint module is shortened, and meanwhile the load capacity and the transmission precision of the joint module are improved.

Description

Technical Field

[0001] This utility model relates to the field of humanoid finger joint technology, and in particular to a harmonic deceleration module for the dexterous hand joint of a humanoid robot. Background Technology

[0002] As an end effector, the dexterous hand of a humanoid robot needs to have a degree of freedom and load-bearing capacity close to that of a human hand. Meanwhile, with the development of humanoid robots, the requirements for lightweight and miniaturized reduction modules for dexterous hand joints are becoming increasingly stringent. Currently, reduction modules for dexterous hand joints typically employ a direct-drive harmonic reducer. The output axes of both the motor and the harmonic reducer are perpendicular to the joint's rotation axis. The rotation is achieved by the bevel gears mounted on the output shaft of the harmonic reducer and the joint's rotation axis, which work together to reverse the direction of the rotation, thus driving the finger joints to rotate and bend.

[0003] However, in actual use, the motor and harmonic reducer are installed within the finger segments of the dexterous hand. The limited installation space places extremely high demands on the performance of the motor and harmonic reducer. In this situation, to ensure the performance of the motor and harmonic reducer, the dexterous hand has to be much larger than a real human hand, affecting its realism. Furthermore, the overall joint module has a relatively weak load-bearing capacity, and the transmission accuracy is limited by the machining precision of the reversing gears, failing to meet higher usage requirements. Utility Model Content

[0004] The purpose of this invention is to provide a harmonic reduction module for the dexterous hand joint of a humanoid robot. By using an axial flux motor and a double rigid wheel harmonic reducer directly connected axially, the output axis of the motor is the rotation axis of the dexterous hand joint. This effectively shortens the axial length of the entire joint module, while the double rigid wheel harmonic reducer directly bears the load and output accuracy, effectively improving the load capacity and transmission accuracy of the entire joint module, and meeting the requirements of lightweight, miniaturized and aesthetically pleasing dexterous hand joint modules.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0006] A harmonic deceleration module for a humanoid robot's dexterous hand joint includes an axial flux motor and a double rigid wheel harmonic reducer coaxially arranged at the joint. The axial flux motor includes a motor housing and an input shaft, a permanent magnet rotor, and two PCB stators installed inside the motor housing. The permanent magnet rotor and the two PCB stators are all coaxially arranged with the input shaft, and the two PCB stators are respectively located on both sides of the permanent magnet rotor.

[0007] The dual-rigid-wheel harmonic reducer includes a wave generator, a flexible bearing, a flex wheel, a first rigid wheel, a second rigid wheel, and a support bearing, all coaxially arranged with the input shaft. The input shaft is fixedly connected to the wave generator. The flexible bearing is disposed between the wave generator and the flex wheel, and the flex wheel meshes with the first and second rigid wheels by a difference in the number of teeth. The support bearing is disposed between the first and second rigid wheels. The first rigid wheel serves as the inner ring of the support bearing and is detachably and fixedly connected to the motor housing. A connecting plate is provided between the first rigid wheel and the motor housing, and the second rigid wheel serves as the outer ring of the support bearing, located on the side of the first rigid wheel away from the motor housing. The flexible bearing includes two first flexible bearings arranged side by side along the input shaft axis. A limiting protrusion is provided in the middle of the inner wall of the flex wheel, located between and abutting against the outer rings of the two first bearings.

[0008] The rigid wheel two is provided with an end cap on the side away from the rigid wheel one. The end cap is detachably and fixedly connected to the rigid wheel two. The motor housing and the rigid wheel two serve as the fixed end and output end of the joint, respectively.

[0009] By adopting the above technical solution, the radial thickness of the axial flux motor is significantly reduced compared to the radial flux motor commonly used in existing technologies. The axial flux motor and the dual rigid wheel harmonic reducer are coaxially and directly connected. The motor housing and the second rigid wheel serve as the fixed end and output end of the joint, respectively. The input shaft axis is the rotation axis of the joint, eliminating the need for other reversing transmission structures. The dual rigid wheel harmonic reducer directly bears the load, effectively improving the load capacity and transmission accuracy of the entire joint module. In the dual rigid wheel harmonic reducer, the axial limit of the flexible wheel is achieved directly by utilizing the cooperation between the outer rings of the two first flexible bearings and the upper limit protrusion of the flexible wheel, eliminating the need for other additional structures for axial limit of the flexible wheel and shortening the axial length of the dual rigid wheel harmonic reducer. The inner and outer rings of the first and second rigid wheels are integrated with the support axial design, effectively reducing the outer diameter and volume of the entire dual rigid wheel harmonic reducer, further meeting the miniaturization and lightweight requirements of the joint module. Alternatively, the thickness of the first and second rigid wheels can be appropriately increased within the limited space to improve the load-bearing capacity of the dual rigid wheel harmonic reducer and meet higher usage requirements.

[0010] Furthermore, the flexible bearing also includes a second flexible bearing disposed between the limiting protrusion and the wave generator, the second flexible bearing being smaller than two first flexible bearings.

[0011] By adopting the above technical solution, the second flexible bearing and the two first flexible bearings work together to make reasonable use of the space between the limiting protrusion and the wave generator, thereby further improving the transmission accuracy and service life of the double rigid wheel harmonic reducer.

[0012] Furthermore, bearings are respectively provided at both ends of the outer wall of the input shaft and between the motor housing and the connecting plate. Limiting steps that cooperate with the outer rings of the corresponding bearings are respectively provided on the motor housing and the connecting plate. Limiting protrusions that cooperate with the inner rings of the two bearings are respectively provided on the input shaft.

[0013] By adopting the above technical solution, the input shaft passes through the inner hole of the wave generator and is fixedly connected to it. The mounting bearings at both ends of the input shaft support the input shaft, and the inner and outer rings of the mounting bearings are limited by the limiting steps and limiting convex rings to avoid deformation or displacement caused by the lengthening of the input shaft, thus ensuring the overall stability of the input shaft installation and operation.

[0014] Furthermore, the motor housing, connecting plate, first rigid wheel, second rigid wheel, and end cover constitute a spherical structure with a planar end cover. The outer diameters of the PCB stator near the dual rigid wheel harmonic reducer, the permanent magnet rotor, and the PCB stator away from the dual rigid wheel harmonic reducer decrease sequentially.

[0015] By adopting the above technical solution, the entire joint module is designed with a near-spherical structure, ensuring that the entire joint module more closely resembles the shape of human hand finger joints and improving the aesthetics of the entire dexterous hand. The dual-rigid-wheel harmonic reducer places relatively high performance requirements on the axial flux motor. The outer diameters of the PCB stator (closer to the dual-rigid-wheel harmonic reducer), the permanent magnet rotor, and the PCB stator (further away from the dual-rigid-wheel harmonic reducer) decrease sequentially. This ensures that the axial flux motor fits the overall near-spherical structure of the joint module while making reasonable use of its internal space to maximize the capacity of the axial flux motor.

[0016] Furthermore, the support bearing is a four-point ball bearing or a cross-roller bearing, and it is arranged in two rows side by side along the input shaft axis.

[0017] By adopting the above technical solution, since the entire joint module is set as a spherical structure, the wall thickness at the location where the support bearing is installed on the rigid wheel is relatively thin, which will result in a smaller and weaker support bearing. Therefore, in this case, the support bearings are arranged in two rows side by side to ensure the performance of the support bearings.

[0018] Furthermore, the motor housing and the outer wall of the rigid wheel are each provided with an outwardly extending mounting lug, and the two mounting lugs are respectively located on both sides of the input shaft.

[0019] By adopting the above technical solution, the motor housing and rigid wheel, i.e., the fixed end and output end of the joint module, are connected to the finger segments of the dexterous hand by using mounting lugs, thereby reducing the overall volume of the joint module while ensuring the connection effect.

[0020] Furthermore, the wave generator has a clearance groove at the end away from the axial flux motor, an encoder is embedded in the clearance groove, and a reading head corresponding to the encoder is installed on the side of the end cover near the encoder.

[0021] By adopting the above technical solution, the encoder is embedded in the clearance slot of the wave generator. The clearance slot is set to allow the reading head to make room for internal installation. The encoder and axial flux motor make reasonable use of the space of the entire joint module, thereby maximizing the capacity and minimizing the size of the joint module and ensuring the compact structure of the joint module.

[0022] In summary, this utility model has the following beneficial effects:

[0023] 1. This utility model adopts a direct connection between an axial flux motor and a double rigid wheel harmonic reducer. The input shaft axis is the rotation axis of the joint module. The axial length of the axial flux motor is greatly shortened. The double rigid wheel harmonic reducer directly uses the cooperation of two first flexible bearings and the upper limit protrusion of the flexible wheel to axially limit the flexible wheel, eliminating the need for an additional axial limiting structure for the flexible wheel. While reducing the axial length of the entire joint module, the double rigid wheel harmonic reducer directly bears the load and output accuracy, effectively improving the load capacity and transmission accuracy of the entire joint module. At the same time, it meets the requirements for lightweight and miniaturized use of the joint module, making the dexterous hand closer to the size of a human hand.

[0024] 2. In this utility model, the motor housing, connecting plate, rigid wheel one, rigid wheel two, and end cover constitute a spherical structure with a flat end cover surface. By setting the entire joint module as a spherical structure, the entire joint module can be made closer to the shape of human hand finger joints, thus improving the aesthetics of the entire dexterous hand.

[0025] 3. In this utility model, rigid wheel one and rigid wheel two directly serve as the inner and outer rings of the support bearing and are integrated with the support bearing. At the same time, the support bearing can be arranged in two rows in parallel to avoid the support bearing being too small due to the thin wall thickness of rigid wheel two, which would affect its performance. While ensuring the overall capacity, the outer diameter and volume of the entire double rigid wheel harmonic reducer are effectively reduced, further meeting the miniaturization and lightweight requirements of the joint module. Alternatively, the thickness of rigid wheel one and rigid wheel two can be appropriately increased in the limited space to improve the load-bearing capacity of the double rigid wheel harmonic reducer and meet higher usage requirements. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a harmonic deceleration module for a humanoid robot's dexterous hand joint in Embodiment 1;

[0027] Figure 2 This is a schematic diagram of the overall structure of a harmonic deceleration module for a humanoid robot's dexterous hand joint in Embodiment 2.

[0028] In the diagram, 1. Axial flux motor; 11. Motor housing; 12. Input shaft; 13. Permanent magnet rotor; 14. PCB stator; 15. Mounting bearing; 16. Limiting step; 17. Limiting protrusion; 18. Connecting plate; 2. Double rigid wheel harmonic reducer; 3. Wave generator; 31. Relief groove; 32. Encoder; 4. First flexible bearing; 41. Second flexible bearing; 5. Flexible wheel; 51. Limiting protrusion; 6. Rigid wheel one; 7. Rigid wheel two; 71. Mounting lug; 8. Support bearing; 9. End cover; 91. Reading head. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0030] Example 1:

[0031] A harmonic deceleration module for the dexterous hand joints of a humanoid robot, such as Figure 1 As shown, the device includes an axial flux motor 1 and a double rigid wheel harmonic reducer 2, which are coaxially arranged at the joint. The axial flux motor 1 includes a motor housing 11 and an input shaft 12, a permanent magnet rotor 13, and two PCB stators 14 installed in the motor housing 11. The permanent magnet rotor 13 and the two PCB stators 14 are coaxially arranged with the input shaft 12, and the two PCB stators 14 are located on both sides of the permanent magnet rotor 13.

[0032] like Figure 1 As shown, the basic structure and working principle of the dual rigid wheel harmonic reducer 2 are similar to those of existing technologies. It includes a wave generator 3, flexible bearings, a flexible wheel 5, a first rigid wheel 6, a second rigid wheel 7, and a support bearing 8. The wave generator 3 is coaxially mounted with the input shaft 12 and is fixedly connected to the input shaft 12 using a method similar to glue. The flexible bearing is positioned between the wave generator 3 and the flexible wheel 5. The flexible wheel 5 meshes with the first rigid wheel 6 and the second rigid wheel 7 by a difference in the number of teeth. The flexible bearing includes two first flexible bearings 4 arranged parallel to each other along the axial direction of the input shaft 12. A limiting protrusion 51 is located in the middle of the inner wall of the flexible wheel 5, positioned between and abutting against the outer rings of the two first flexible bearings. The axial movement of the flexible wheel 5 is achieved by the cooperation of the outer rings of the two first flexible bearings 4 and the limiting protrusion 51.

[0033] like Figure 1As shown, the support bearing 8 is disposed between the first rigid wheel 6 and the second rigid wheel 7. The first rigid wheel 6 serves as the inner ring of the support bearing 8 and is detachably and fixedly connected to the motor housing 11. A connecting plate 18 is provided between the first rigid wheel 6 and the motor housing 11 and is detachably and fixedly connected to it to facilitate the installation of internal components of the axial flux motor 1. The second rigid wheel 7 serves as the outer ring of the support bearing 8 and is located on the side of the first rigid wheel 6 away from the motor housing 11. An end cover 9 is provided on the side of the second rigid wheel 7 away from the first rigid wheel 6. The end cover 9 is detachably and fixedly connected to the second rigid wheel 7. The motor housing 11 and the second rigid wheel 7 serve as the fixed end and output end of the joint, respectively.

[0034] like Figure 1 As shown, the support bearing 8 is a four-point ball bearing or a cross-roller bearing. The first rigid wheel 6 and the second rigid wheel 7 are integrated with the support axis as the inner and outer rings of the support bearing 8, effectively reducing the outer diameter and volume of the entire dual rigid wheel harmonic reducer 2. This further meets the miniaturization and lightweight requirements of the joint module. Alternatively, within a limited space, the thickness of the first rigid wheel 6 and the second rigid wheel 7 can be appropriately increased to improve the load-bearing capacity of the dual rigid wheel harmonic reducer 2 and meet higher usage requirements.

[0035] like Figure 1 As shown, this utility model employs an axial flux motor 1, which significantly shortens the axial length compared to the radial flux motors used in the prior art. Furthermore, the axial flux motor 1 features a dual-stator, single-rotor structure, with two PCB stators 14 located on either side of the permanent magnet rotor 13. This allows for higher output power and torque within the same volume, meaning its axial thickness can be reduced while still meeting usage requirements. Simultaneously, the axial flux motor 1 exhibits excellent heat dissipation performance, eliminating the need for additional heat dissipation structures and further reducing its axial thickness. This facilitates direct connection between the axial flux motor 1 and the dual-rigid-wheel harmonic reducer 2, allowing the joint module to rotate around the input shaft 12. The dual-rigid-wheel harmonic reducer 2 directly bears the load, effectively improving the load capacity and transmission accuracy of the entire joint module.

[0036] like Figure 1 As shown, in this embodiment, mounting bearings 15 are respectively provided at both ends of the outer wall of the input shaft 12 and between the motor housing 11 and the connecting plate 18. Limiting steps 16 that mate with the outer rings of the corresponding mounting bearings 15 are provided on the motor housing 11 and the connecting plate 18. Limiting protrusions 17 that mate with the inner rings of the two mounting bearings 15 are provided on the input shaft 12. The mounting bearings 15 at both ends of the input shaft 12 support the input shaft 12, and the limiting steps 16 and limiting protrusions 17 limit the inner and outer rings of the mounting bearings 15, preventing deformation or displacement of the input shaft 12, especially due to its increased length, and ensuring the overall stability of the input shaft 12 during installation and operation.

[0037] like Figure 1As shown, to make the entire dexterous hand joint module more closely resemble a human finger joint and improve its aesthetics, in this embodiment, the motor housing 11, connecting plate 18, rigid wheel one 6, rigid wheel two 7, and end cover 9 constitute a near-spherical structure with the end cover 9 being planar; that is, the entire joint module has a near-spherical structure. In this case, the outer diameters of the PCB stator 14 near the dual rigid wheel harmonic reducer 2, the permanent magnet rotor 13, and the PCB stator 14 away from the dual rigid wheel harmonic reducer 2 decrease sequentially. This ensures that the axial flux motor 1 is compatible with the overall near-spherical structure of the joint module, rationally utilizing its internal space to maximize the capacity of the axial flux motor 1 and meet the usage requirements of the dual rigid wheel harmonic reducer 2.

[0038] like Figure 1 As shown, in order to facilitate the connection between the fixed end and the output end and the finger segments of the dexterous hand, an outwardly extending mounting lug 71 is provided on the outer wall of the motor housing 11 and the outer wall of the second rigid wheel 7, respectively, and located on both sides of the input shaft 12. The mounting lug 71 is used to connect the motor housing 11 and the second rigid wheel 7 to the outside, thereby reducing the overall volume of the joint module while ensuring the connection effect.

[0039] In addition, such as Figure 1 As shown, a clearance groove 31 is provided at the end of the wave generator 3 away from the axial flux motor 1. An encoder 32 is embedded in the clearance groove 31. A reading head 91 corresponding to the encoder 32 is installed on the side of the end cover 9 near the encoder 32. By embedding the encoder 32 in the clearance groove 31 of the wave generator 3, the clearance groove 31 is configured to allow internal installation space for the reading head 91. The encoder 32 and the axial flux motor 1 make reasonable use of the space of the entire joint module, maximizing the capacity and minimizing the size of the joint module, and ensuring the structural compactness of the joint module.

[0040] Example 2:

[0041] A harmonic deceleration module for the dexterous hand joints of a humanoid robot, such as Figure 1 and Figure 2 As shown, the difference from Embodiment 1 is that the flexible bearing also includes a second flexible bearing 41 disposed between the limiting protrusion 51 and the wave generator 3. The second flexible bearing 41 is smaller than two first flexible bearings 4. The second flexible bearing 41 and the two first flexible bearings 4 work together to make reasonable use of the space between the limiting protrusion 51 and the wave generator 3, further improving the transmission accuracy and service life of the double rigid wheel harmonic reducer 2.

[0042] In addition, such as Figure 2As shown, the support bearings 8 are arranged in two rows along the input shaft 12. This avoids the situation where the wall thickness at the location where the support bearings 8 are installed on the rigid wheel 7 is too thin, causing the support bearings 8 to be too small. A single row of support bearings 8 cannot meet the usage requirements. By setting the support bearings 8 in two rows in parallel, their performance is improved and higher usage requirements are met.

[0043] The foregoing description illustrates and describes preferred embodiments of the present invention. As previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A harmonic reduction module for a humanoid robot dexterous hand joint, characterized by: The application relates to a joint comprising an axial flux motor (1) and a double rigid wheel harmonic reducer (2), wherein the axial flux motor (1) comprises a motor shell (11) and an input shaft (12), a permanent magnet rotor (13) and two PCB stators (14) which are coaxially arranged in the motor shell (11), and the permanent magnet rotor (13) and the two PCB stators (14) are coaxially arranged with the input shaft (12), and the two PCB stators (14) are respectively arranged on the two sides of the permanent magnet rotor (13). The double rigid wheel harmonic reducer (2) comprises a wave generator (3), a flexible bearing, a flexible wheel (5), a rigid wheel one (6), a rigid wheel two (7) and a support bearing (8) which are coaxially arranged with the input shaft (12), the input shaft (12) is fixedly connected with the wave generator (3), the flexible bearing is arranged between the wave generator (3) and the flexible wheel (5), the flexible wheel (5) is engaged with the rigid wheel one (6) and the rigid wheel two (7) with different tooth numbers, the support bearing (8) is arranged between the rigid wheel one (6) and the rigid wheel two (7), the rigid wheel one (6) serves as an inner ring of the support bearing (8) and is detachably fixedly connected with the motor shell (11), a connecting plate (18) which is detachably fixedly connected with the rigid wheel one (6) and the motor shell (11) is arranged between the rigid wheel one (6) and the motor shell (11), the rigid wheel two (7) serves as an outer ring of the support bearing (8) and is arranged on the side of the rigid wheel one (6) which is away from the motor shell (11), the flexible bearing comprises two first flexible bearings (4) which are arranged in parallel along the axial direction of the input shaft (12), and a limiting protrusion (51) is arranged in the middle of the inner wall of the flexible wheel (5) and located between the outer rings of the two first bearings and abuts against the outer rings. An end cover (9) is arranged on the side of the rigid wheel two (7) which is away from the rigid wheel one (6), the end cover (9) is detachably fixedly connected with the rigid wheel two (7), and the motor shell (11) and the rigid wheel two (7) serve as a fixed end and an output end of the joint respectively.

2. The harmonic reduction module for the joint of a humanoid robot dexterous hand according to claim 1, characterized in that: The flexible bearing further comprises a second flexible bearing (41) which is arranged between the limiting protrusion (51) and the wave generator (3), and the second flexible bearing (41) is smaller than the two first flexible bearings (4).

3. The harmonic reduction module for the joint of a humanoid robot dexterous hand according to claim 1, characterized in that: Mounting bearings (15) are arranged between the two ends of the outer wall of the input shaft (12) and the motor shell (11) and the connecting plate (18) respectively, limiting steps (16) which are matched with the outer rings of the corresponding mounting bearings (15) are arranged on the motor shell (11) and the connecting plate (18) respectively, and limiting convex rings (17) which are matched with the inner rings of the two mounting bearings (15) are arranged on the input shaft (12).

4. The harmonic reduction module for the joint of a humanoid robot dexterous hand according to claim 1, characterized in that: The motor shell (11), the connecting plate (18), the rigid wheel one (6), the rigid wheel two (7) and the end cover (9) form a spherical structure, the outer diameters of the PCB stator (14) close to the double rigid wheel harmonic reducer (2), the permanent magnet rotor (13) and the PCB stator (14) far away from the double rigid wheel harmonic reducer (2) gradually decrease in sequence.

5. The harmonic reduction module for the joint of a humanoid robot dexterous hand according to claim 4, characterized in that: The support bearing (8) is a four-point ball bearing or a cross roller bearing, and two rows of the support bearing (8) are arranged in parallel along the axial direction of the input shaft (12).

6. The harmonic reduction module for the joint of a humanoid robot dexterous hand according to claim 1 or 4, characterized in that: The motor housing (11) and the outer wall of the second rigid wheel (7) are respectively provided with an outwardly extending mounting lug (71), and the two mounting lugs (71) are respectively located on the two sides of the input shaft (12).

7. The harmonic reduction module for the joint of a humanoid robot dexterous hand according to claim 1, characterized in that: The wave generator (3) is provided with a let-out slot (31) away from one end of the axial flux motor (1), an encoder (32) is embedded in the let-out slot (31), and a reading head (91) corresponding to the encoder (32) is mounted on the side of the end cover (9) close to the encoder (32).

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