Robot joint module

Abstract

The invention provides a robot joint module in the technical field of robot manufacturing. The robot joint module comprises a motor assembly, a harmonic speed reducer assembly and an encoder assembly. The double-rigid-gear harmonic speed reducer and the outer rotor motor are adopted, the motor is embedded into a flexible gear of the harmonic speed reducer, the axial length of the joint module is effectively shortened, and the radial size is reduced; the motor rotor is elliptical and is in contact with the inner ring of the flexible bearing, and the outer ring of the flexible bearing is in contact with the inner ring of the flexible gear of the harmonic speed reducer, so that the motor rotor shell and the flexible bearing jointly serve as a harmonic generator, and meanwhile, the motor stator shell and the harmonic speed reducer shell are integrally designed, so that the number of parts is reduced; the rotor end cover, the rotor rotating shaft, the output flange and the output shaft are all integrally designed into hollow shafts, and the output hollow shaft of the output flange is arranged in the rotor hollow shaft, so that cables can be arranged in the module. The integrated design of motor parts and harmonic reducer parts has the cost advantage in the aspects of manufacturing and maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of robot manufacturing, and in particular to a robot joint module. Background Art

[0002] With the increase in labor costs and the rapid development of science and technology, robotics has been widely used in factories and service industries. As the core component of robots, joint modules play a vital role in improving the robot's motion performance.

[0003] At present, the design trend of robot joint modules is moving towards miniaturization, and at the same time, the wiring problem needs to be solved to optimize robot control. Traditional robots usually use external wiring, which is not only messy, but may also cause safety issues. Therefore, the market is in urgent need of more compact joint modules. For the increasing number of robot applications in production lines and life scenarios, especially robots that need to collaborate or move with humans, there are strict requirements on the size and weight of joint modules, so it is particularly important to reduce the volume and mass of joint modules. Traditional robot joint modules are increasingly difficult to meet these miniaturized application requirements.

[0004] However, the existing robot joint modules usually use planetary reducers as core components and integrate motors, encoders and other components. This design integrates the main components in an axial stack, resulting in a longer axial length of the module. In addition, due to the large radial size of the planetary reducer, the volume of the entire module is also correspondingly larger. Moreover, the cables of the planetary reducer joint module need to be routed outside the module, which not only takes up more space on the entire machine, but also poses a safety hazard.

[0005] In addition, there is also a top-hat type harmonic reducer (also called a hat-type harmonic reducer) as the basis, and its flexible wheel is in the shape of a top-hat. In this design, the input shaft and the output shaft are connected to the harmonic reducer, while the motor, brake, encoder and drive plate are axially mounted on the input shaft and the output shaft. The input shaft and the output shaft are usually designed as coaxial hollow cylindrical shafts, and the hollow part is used to arrange the line. The input shaft is located on the outside of the output shaft, and the output shaft is longer than the input shaft so that the encoder can be installed to realize the feedback of the input shaft and the output shaft speed. However, the internal space of the harmonic reducer is not fully utilized except for passing through the input shaft and the output shaft. Other components are connected to the harmonic reducer axially, which also makes the axial length of the joint module longer and fails to effectively reduce the overall volume of the module. Summary of the invention

[0006] The present invention provides a robot joint module with lower cost and higher integration than the existing robot joint module, adopts a double rigid wheel harmonic reducer and an outer rotor motor, and an elliptical motor rotor housing, so that the motor rotor housing and the flexible bearing act as a harmonic generator together, and the rotor end cover and the rotor shaft, the output flange and the output shaft are all integrated into a hollow shaft, and the output hollow shaft of the output flange can be built into the hollow shaft of the rotor. The motor parts and the harmonic reducer parts of the present invention are all integrated and designed, so that it has cost advantages in both manufacturing and maintenance.

[0007] To achieve the above-mentioned purpose, the present invention adopts the following technical solution: a robot joint module, including three parts: a motor assembly, a harmonic reducer assembly and an encoder assembly.

[0008] The motor assembly is an independent module, which consists of a flange base, a stator core, a winding, a second bearing, a third bearing, a magnetic steel, a rotor housing, a rotor end cover, a second oil seal and a shaft retaining ring. The upper and lower end faces of the second oil seal are respectively fitted with the inner end face of the flange base and the end face of the rotor housing. The outer ring of the rotor housing is set to an elliptical shape. The flange base is provided with a wire outlet hole for the cable to pass through and connect to the external drive PCBA.

[0009] A harmonic reducer assembly includes: a stationary rigid wheel, an output rigid wheel, a first bearing, a flexible wheel, a flexible bearing, a first screw, and an output flange. The inner side of the roller of the flexible bearing is interference-fitted with the elliptical outer ring of the rotor housing, and the outer side of the roller is in contact with the inner ring of the flexible wheel; a certain number of teeth are evenly distributed on the outer ring of the flexible wheel, which match the same number of teeth on the inner ring of the stationary rigid wheel. The outer ring of the stationary rigid wheel is interference-fitted with the inner ring of the flange base and fixedly connected. The first bearing is installed in the flange base, and its outer ring is fixedly connected with the inner ring of the flange base. The output rigid wheel is fixed to the output flange by the first screw, and the outer ring of the output rigid wheel is coaxially matched with the inner ring of the output flange; the output rigid wheel and the output flange are placed in the flange base, and the end face of the output flange is in contact with the end face of the first bearing; the inner ring of the first bearing is matched with the outer ring of the output rigid wheel and fixedly connected.

[0010] Encoder assembly: It includes the fourth bearing, encoder main gear, encoder cover, encoder magnet, second screw, fifth bearing, encoder sub-gear, encoder housing, magnetic induction chip, PCBA and third screw, and is an independent module. The encoder sub-gear has the same number of teeth as the encoder main gear, and they mesh with each other for driving. The inner hole of the encoder sub-gear has a built-in high-performance two-pole encoder magnet, which rotates with the encoder sub-gear and carries the speed and position information of the motor rotor. The magnetic induction chip is welded on the PCBA.

[0011] The motor rotor end cover is provided with a hollow shaft, the output flange is provided with an output flange hollow shaft, the encoder main gear is provided with a hollow hole, and the output flange hollow shaft passes through the hollow shaft of the motor rotor end cover and the hollow hole of the encoder main gear.

[0012] The stopper of the encoder main gear and the stopper of the hollow shaft of the rotor end cover of the motor assembly are concave-convex matching structures.

[0013] A first oil seal is provided on the hollow shaft of the output flange, and its inner ring is interference fit with the outer ring of the hollow shaft of the output flange; the upper and lower end faces of the first oil seal are respectively fitted with the outer end face of the rotor end cover and the inner end face of the output flange.

[0014] The entire encoder assembly is fixed to the flange base by a third screw, and the inner ring of the stopper of the encoder housing and the outer ring of the stopper of the flange base are coaxially matched with each other; the inner end face of the stopper of the encoder housing fits with the end face of the stopper of the flange base.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) Double rigid-wheel harmonic reducer and external rotor motor, the motor is embedded inside the flexible wheel of the harmonic reducer, effectively shortening the axial length of the joint module and reducing the radial size;

[0017] (2) The motor rotor is designed to be elliptical in shape and in contact with the inner ring of the flexible bearing, while the outer ring of the flexible bearing is in contact with the inner ring of the harmonic reducer flexible wheel. The motor rotor housing and the flexible bearing can act as a harmonic generator together. When the motor rotor rotates, the roller of the flexible bearing produces periodic radial deformation, which in turn drives the flexible wheel to produce periodic deformation, driving the rigid wheel with a different number of teeth from the flexible wheel to rotate. The output rigid wheel is connected to the output flange by screws, thereby achieving the output of torque and speed;

[0018] (3) The motor stator housing and the harmonic reducer housing adopt an integrated design, which reduces the number of parts, simplifies the assembly process, and reduces the module size;

[0019] (4) The rotor end cover and the rotor shaft are integrated into a hollow shaft, and the output flange and the output shaft are also integrated into a hollow shaft. The output hollow shaft of the output flange is built into the hollow shaft of the rotor. This design allows cables to be arranged inside the module, which facilitates the cable routing between the joint module and other modules of the robot, and improves the overall space utilization and aesthetics.

[0020] In summary, a robot joint module of the present invention reduces the number of parts, simplifies the assembly process, reduces the complexity and cost of the device, and also reduces the failure rate of the equipment and improves the reliability of the equipment. Secondly, the motor parts and harmonic reducer parts of the robot joint module of the present invention are all designed in an integrated manner, so that it has cost advantages in both manufacturing and maintenance. The compact structure and the design of the hollow shaft not only simplify the number of parts and optimize the device structure, but also improve the overall space utilization and aesthetics. Therefore, the present invention has a broad market demand, especially in scenes with complex functions, high space requirements, and strong aesthetics, such as household service robots, market service robots and other industries, and has huge application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 A cross-sectional view of a robot joint module of the present invention;

[0023] Figure 2 This is a view of a motor component of a robot joint module of the present invention;

[0024] Figure 3 This is a view of a flexible bearing assembly of a robot joint module of the present invention;

[0025] Figure 4 This is a view of a stationary rigid wheel of a robot joint module of the present invention;

[0026] Figure 5 This is a view of an output rigid wheel of a robot joint module of the present invention;

[0027] Figure 6 This is a flexible wheel view of a robot joint module of the present invention;

[0028] Figure 7 This is a view of an output flange of a robot joint module of the present invention;

[0029] Figure 8 This is a view of a motor oil seal of a robot joint module of the present invention;

[0030] Fig. 9 This is a view of an output oil seal of a robot joint module of the present invention;

[0031] Fig.10 This is a view of the encoder main gear of a robot joint module of the present invention;

[0032] Fig.11This is a view of an encoder sub-gear of a robot joint module of the present invention;

[0033] Fig.12 This is a view of an encoder component of a robot joint module of the present invention;

[0034] Fig.13 This is a view of the rotor shell of a robot joint module of the present invention.

[0035] The above drawings include the following reference numerals:

[0036] 1. Flange base; 2. Stationary rigid wheel; 3. Output rigid wheel; 4. First bearing; 5. Flexible wheel; 6. Flexible bearing; 7. First screw; 8. Output flange; 9. Rotor end cover; 10. Second bearing; 11. First oil seal; 12. Stator core; 13. Winding; 14. Magnetic steel; 15. Rotor housing; 16. Second oil seal; 17. Third bearing; 18. Shaft retaining ring; 19. Fourth bearing; 21. Encoder main gear; 22. Encoder cover; 23. Encoder magnet; 24. Second screw; 25. Fifth bearing; 26. Encoder sub-gear; 27. Encoder housing; 28. Magnetic induction chip; 29. ​​PCBA; 30. Third screw;

[0037] 101, first end face of flange base; 103, first inner ring of flange base; 104, second end face of flange base; 105, second inner ring of flange base; 108, outer ring of flange base stopper; 109, end face of flange base stopper; 110, wire outlet hole of flange base; 201, outer ring of stationary rigid wheel; 202, inner ring teeth of stationary rigid wheel; 301, outer ring of output rigid wheel; 501, inner ring of flexible wheel; 503, outer ring teeth of flexible wheel; 602, flexible bearing roller; 6021, outer side of flexible bearing roller; 6022, inner side of flexible bearing roller; 804, output Inner end face of flange; 805, hollow shaft of output flange; 806, inner ring of output flange; 807, end face of output flange; 902, outer end face of rotor end cover; 903, hollow shaft of motor rotor end cover; 904, stopper of hollow shaft of rotor end cover; 1101, inner ring of oil seal; 1501, outer ring of rotor housing; 1502, end face of rotor housing; 2101, stopper of encoder main gear; 2102, hollow hole of encoder main gear; 2602, inner hole of encoder sub-gear; 2701, inner ring of encoder housing stopper; 2702, inner end face of encoder housing stopper. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and the embodiments in this application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that, unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which this application belongs. The terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. The terms "disposed", "connected", "connected", "through" and "through" used in this specification and claims should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a communication between two elements. When the terms "comprising" and / or "including" are used in this specification and claims, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof. The present invention relates to orientation descriptions, such as the orientation or positional relationship indicated by up, down, front, back, left, right, horizontal, vertical, etc., which is based on the orientation or positional relationship shown in the drawings, is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or described herein.

[0040] As attached Figure 1 To Attachment Fig.13 As shown, a robot joint module includes: a motor assembly, a harmonic reducer assembly and an encoder assembly.

[0041] The motor assembly is an independent module, including: flange base 1, stator core 12, winding 13, second bearing 10, third bearing 17, magnetic steel 14, rotor housing 15, rotor end cover 9, second oil seal 16 and shaft retaining ring 18. The upper and lower end faces of the second oil seal 16 are respectively fitted with the first end face 101 of the flange base and the end face 1502 of the rotor housing 15 to achieve a sealing effect, prevent the lubricating grease of the harmonic reducer from penetrating into the motor, and avoid motor failure. The outer ring 1501 of the rotor housing 15 is set to an elliptical shape; the flange base 1 is provided with a wire outlet hole 110, which can be used for cables to pass through and connect to the external drive PCBA.

[0042] Harmonic reducer assembly: includes a stationary rigid wheel 2, an output rigid wheel 3, a first bearing 4, a flexible wheel 5, a flexible bearing 6, a first screw 7, and an output flange 8. The inner side 6022 of the flexible bearing roller 602 is interference fit with the elliptical outer ring 1501 of the rotor housing 15, and the outer side 6021 of the flexible bearing roller 602 is in contact with the inner ring 501 of the flexible wheel 5. A certain number of teeth 503 are evenly distributed on the outer ring of the flexible wheel 5, which match the same number of teeth 202 on the inner ring of the stationary rigid wheel 2. Since the number of teeth of the flexible wheel 5 and the stationary rigid wheel 2 is the same, when the flexible wheel 5 is deformed radially periodically, the stationary rigid wheel 2 will not rotate relative to the flexible wheel 5. The outer ring 201 of the stationary rigid wheel 2 is interference fit and fixedly connected with the first inner ring 103 of the flange base, for example, they can be fixedly connected by pins to prevent the stationary rigid wheel 2 from moving radially when subjected to force; the first bearing 4 is installed in the flange base 1, and its outer ring is fixedly connected with the second inner ring 105 of the flange base, for example, by strong fixing glue, to ensure that the end face of the first bearing 4 fits with the second end face 104 of the flange base to prevent the first bearing 4 from moving radially and axially. The output rigid wheel 3 is connected and fixed with the output flange 8 by the first screw 7, and the outer ring 301 of the output rigid wheel 3 is precisely matched with the inner ring 806 of the output flange 8 to ensure coaxiality. The output rigid wheel 3 and the output flange 8 are placed in the flange base 1 equipped with the first bearing 4, the flexible wheel 5, the flexible bearing 6 and the motor assembly. The end face 807 of the output flange 8 is fitted with the end face of the first bearing 4 to achieve axial positioning. The inner ring of the first bearing 4 is matched and fixedly connected with the outer ring 301 of the output rigid wheel 3, for example, by using a strong fixing glue to prevent the output rigid wheel 3 and the output flange 8 from radial and axial movement. This design allows the motor rotor housing 15 and the flexible bearing 6 to act as a harmonic generator together. When the motor rotor rotates, the elliptical outer ring 1501 of the rotor housing 15 forces the flexible bearing 6 to produce periodic radial deformation, thereby driving the flexible wheel 5 to produce periodic deformation. The stationary rigid wheel 2 with the same number of teeth as the flexible wheel 5 does not produce relative rotation, while the output rigid wheel 3 with two more teeth than the flexible wheel 5 only rotates and moves by two teeth in the circumferential direction when the flexible wheel 5 undergoes a full circle of radial deformation, thereby achieving the output of torque and speed.

[0043] The encoder assembly includes: a fourth bearing 19, an encoder main gear 21, an encoder cover 22, an encoder magnet 23, a second screw 24, a fifth bearing 25, an encoder sub-gear 26, an encoder housing 27, a magnetic induction chip 28, a PCBA 29 and a third screw 30. The encoder sub-gear 26 has the same number of teeth as the encoder main gear 21, and they are meshed and driven with each other, so the rotation speed of the encoder sub-gear 26 is the same as that of the encoder main gear 21, that is, the same as the rotation speed of the motor rotor. The inner hole 2602 of the encoder sub-gear 26 is built with a high-performance two-pole encoder magnet 23, and the magnet 23 rotates with the encoder sub-gear 26, carrying the speed and position information of the motor rotor. The magnetic induction chip 28 is welded on the PCBA 29, and the speed and position information of the motor rotor are obtained by collecting the N / S magnetic pole position and change speed of the encoder magnet 23, and the information is transmitted to the drive controller as a feedback signal to realize the control of the motor speed and torque.

[0044] Furthermore, the motor rotor end cover 9 is provided with a hollow shaft 903, the output flange 8 is provided with an output flange hollow shaft 805, the encoder main gear 21 is provided with a hollow hole 2102, and the output flange hollow shaft 805 passes through the hollow shaft 903 of the motor rotor end cover 9 and the hollow hole 2102 of the encoder main gear 21. This design allows cables to be arranged inside the module, facilitates the cable routing between the joint module and other modules of the robot, and improves the overall space utilization and aesthetics.

[0045] Furthermore, the stop 2101 of the encoder main gear 21 and the hollow shaft stop 904 of the motor assembly rotor end cover 9 are concave-convex matching structures, so that the drive encoder main gear 21 rotates at the same speed when the motor rotates.

[0046] Furthermore, the output flange hollow shaft 805 is provided with the first oil seal 11, whose inner ring 1101 is interference fit with the outer ring of the output flange hollow shaft 805, and the upper and lower end faces of the first oil seal 11 are respectively fitted with the outer end face 902 of the rotor end cover 9 and the inner end face 804 of the output flange 8, so as to achieve a sealing effect and prevent the lubricating grease of the harmonic reducer from entering the hollow shaft 903 of the motor rotor end cover 9 and flowing out to the outside of the joint module.

[0047] In some embodiments of the present invention, the entire encoder assembly can be fixed to the flange base 1 by the third screw 30, and the stop inner ring 2701 of the encoder housing 27 cooperates with the stop outer ring 108 of the flange base 1 to ensure the coaxiality of the encoder main gear 21 and the motor assembly, and realize smooth rotation and accurate transmission of the motor rotor position and speed information. The stop inner end face 2702 of the encoder housing 27 fits with the stop end face 109 of the flange base 1, which plays an axial positioning and limiting role, and facilitates the rapid installation of the encoder assembly.

[0048] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. At the same time, for ordinary technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A robot joint module, characterized in that: include: Motor assembly, harmonic reducer assembly and encoder assembly; The motor assembly is an independent module, including: a flange base, a stator core, a winding, a second bearing, a third bearing, a magnetic steel, a rotor housing, a rotor end cover, a second oil seal and a shaft retaining ring; the upper and lower end faces of the second oil seal are respectively fitted with the inner end face of the flange base and the end face of the rotor housing, the outer ring of the rotor housing is set to an elliptical shape, and the flange base is provided with a wire outlet hole for the cable to pass through and connect to the external drive PCBA; A harmonic reducer assembly, comprising: a stationary rigid wheel, an output rigid wheel, a first bearing, a flexible wheel, a flexible bearing, a first screw, and an output flange; the inner side of the roller of the flexible bearing is interference-fitted with the elliptical outer ring of the rotor housing, and the outer side of the roller is in contact with the inner ring of the flexible wheel; a certain number of teeth are evenly distributed on the outer ring of the flexible wheel, which match the same number of teeth on the inner ring of the stationary rigid wheel; the outer ring of the stationary rigid wheel is interference-fitted with the inner ring of the flange base and fixedly connected; the first bearing is installed in the flange base, and its outer ring is fixedly connected to the inner ring of the flange base, the output rigid wheel is connected and fixed to the output flange by the first screw, and the outer ring of the output rigid wheel is coaxially matched with the inner ring of the first bearing; the output rigid wheel and the output flange are placed in the flange base, and the end face of the output flange fits with the end face of the first bearing; The encoder assembly, an independent module, includes a fourth bearing, an encoder main gear, an encoder cover, an encoder magnet, a second screw, a bearing, an encoder sub-gear, an encoder housing, a magnetic induction chip, a PCBA and a third screw; the encoder sub-gear has the same number of teeth as the encoder main gear and is meshed and driven with each other; a high-performance two-pole encoder magnet is built into the inner hole of the encoder sub-gear, and the encoder magnet rotates with the encoder sub-gear and carries the speed and position information of the motor rotor; the magnetic induction chip is welded on the PCBA.

2. A robot joint module according to claim 1, characterized in that: The motor rotor end cover is provided with a hollow shaft, the output flange is provided with an output flange hollow shaft, the encoder main gear is provided with a hollow hole, and the output flange hollow shaft passes through the motor rotor end cover hollow shaft and the encoder main gear hollow hole.

3. A robot joint module according to claim 2, characterized in that: The stopper of the encoder main gear and the stopper of the hollow shaft of the rotor end cover of the motor assembly are concave-convex matching structures.

4. A robot joint module according to claim 2, characterized in that: A first oil seal is provided on the hollow shaft of the output flange, and its inner ring is interference fit with the outer ring of the hollow shaft of the output flange; the upper and lower end faces of the first oil seal are respectively fitted with the outer end face of the rotor end cover and the inner end face of the output flange.

5. The encoder assembly of a robot joint module according to claim 1, characterized in that: The entire encoder assembly is fixed to the flange base by a third screw, and the inner ring of the stopper of the encoder housing and the outer ring of the stopper of the flange base are coaxially matched with each other; the inner end face of the stopper of the encoder housing is fitted with the end face of the stopper of the flange base; the upper and lower end faces of the second oil seal are respectively fitted with the inner end face of the flange base and the end face of the rotor housing.

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