Two-stage transmission harmonic reducer module, joint module and robot

Abstract

The application discloses a kind of two-stage transmission harmonic reducer module, joint module and robot, including first stage reducer, second stage reducer and fixed shaft, first stage reducer includes first wave generator, first flexible wheel, first rigid wheel and first cross roller bearing, first flexible wheel is connected with the first inner ring of first cross roller bearing, and first rigid wheel is connected with the first outer ring of first cross roller bearing;Second stage reducer includes second wave generator, second flexible wheel, second rigid wheel and second cross roller bearing, and second flexible wheel is connected to the first outer ring of first cross roller bearing and the second outer ring of second cross roller bearing respectively, and second rigid wheel is connected with the second inner ring of second cross roller bearing;The first end of fixed shaft is connected to the first inner ring of first cross roller bearing, and the second end of fixed shaft is connected to second wave generator.The application can improve the versatility and maintainability of harmonic reducer module.

Description

Technical Field

[0001] This invention relates to the field of speed reducer technology, and in particular to a two-stage transmission harmonic speed reducer module, a joint module, and a robot. Background Technology

[0002] Harmonic reducers are transmission devices that use a wave generator to induce controllable elastic deformation of a flex wheel, which then meshes with a rigid wheel to transmit motion and power. They are widely used in industrial robots, aerospace, and other fields. Current technology achieves high transmission ratios through multi-stage harmonic reducers. However, the first and second stages of existing multi-stage harmonic reducers typically share a common transmission structure (such as a flex wheel or a rigid wheel), requiring separate design and manufacturing, resulting in higher costs and limited application. Furthermore, the flex wheel is prone to fatigue damage due to prolonged deformation. Integrated multi-stage harmonic reducers either require custom-made flex wheels for replacement or complete replacement, which is inconvenient for maintenance. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a two-stage transmission harmonic reducer module, a joint module, and a robot, which can improve the versatility and maintainability of the harmonic reducer module.

[0004] On one hand, embodiments of the present invention provide a two-stage drive harmonic reducer module, comprising:

[0005] The first-stage reducer includes a first wave generator, a first flexible wheel, a first rigid wheel, and a first crossed roller bearing. The first flexible wheel is sleeved between the first wave generator and the first rigid wheel, and the external teeth of the first flexible wheel mesh with the internal teeth of the first rigid wheel. The first flexible wheel is connected to the first inner ring of the first crossed roller bearing, and the first rigid wheel is connected to the first outer ring of the first crossed roller bearing.

[0006] The second-stage reducer includes a second wave generator, a second flexible wheel, a second rigid wheel, and a second crossed roller bearing. The second flexible wheel is sleeved between the second wave generator and the second rigid wheel, and the external teeth of the second flexible wheel mesh with the internal teeth of the second rigid wheel. The second flexible wheel is connected to the first outer ring of the first crossed roller bearing and the second outer ring of the second crossed roller bearing, respectively. The second rigid wheel is connected to the second inner ring of the second crossed roller bearing.

[0007] A fixed shaft, the first end of which is connected to the first inner ring of the first crossed roller bearing, and the second end of which is connected to the second wave generator.

[0008] According to some embodiments of the present invention, the first flexible wheel is a cup-shaped short cylinder structure, and the second flexible wheel is a top hat-shaped short cylinder structure.

[0009] According to some embodiments of the present invention, the first stage reducer is provided with a first cavity, the second stage reducer is provided with a second cavity, the first cavity and the second cavity form an internal assembly cavity, and the fixed shaft is located in the internal assembly cavity.

[0010] According to some embodiments of the present invention, the fixed shaft includes a shaft body and a shaft cover. The shaft body has a hollow structure. A shaft connecting portion is provided at a first end of the shaft body. The shaft connecting portion is provided with a plurality of first connecting holes. A plurality of first snap-fit ​​portions are provided at a second end of the shaft body. The shaft cover is provided with a plurality of second connecting holes and a plurality of second snap-fit ​​portions. The shaft connecting portion is connected to the first inner ring of the first crossed roller bearing through the first connecting holes. The shaft body and the shaft cover are connected by the first snap-fit ​​portions and the second snap-fit ​​portions. The shaft cover is connected to the second wave generator through the second connecting holes.

[0011] According to some embodiments of the present invention, the first inner ring of the first crossed roller bearing is provided with a plurality of third connecting holes, the first connecting hole being adapted to the third connecting holes, and the second wave generator is provided with a plurality of fourth connecting holes, the second connecting hole being adapted to the fourth connecting holes.

[0012] According to some embodiments of the present invention, the first wave generator is provided with a first clearance hole, the first inner ring of the first crossed roller bearing is provided with a second clearance hole, the second wave generator is provided with a third clearance hole, the shaft connection portion of the shaft body is provided with a fourth clearance hole, and the middle portion of the shaft cover is provided with a fifth clearance hole. The first clearance hole, the second clearance hole, the third clearance hole, the fourth clearance hole, and the fifth clearance hole are located on the same axis and form a clearance channel.

[0013] According to some embodiments of the present invention, the width-to-diameter ratio of the first-stage reducer is 0.29, and the width-to-diameter ratio of the second-stage reducer is 0.20.

[0014] According to some embodiments of the present invention, a first flexible bearing is installed between the first wave generator and the first flexible wheel, and a second flexible bearing is installed between the second wave generator and the second flexible wheel.

[0015] On the other hand, embodiments of the present invention provide a joint module, including the above-mentioned two-stage transmission harmonic reducer module.

[0016] In another aspect, embodiments of the present invention provide a robot including the aforementioned joint module.

[0017] The embodiments of the present invention have at least the following beneficial effects:

[0018] Both the first-stage and second-stage reducers are structurally complete and independently operable harmonic reducers, connected detachably via a fixed shaft. The first-stage reducer provides single-stage reduction, while the second-stage reducer offers high transmission accuracy and allows for precise fine-tuning. The two stages can be used independently or in combination, significantly improving the versatility of the reducer module. If a stage reducer fails, the faulty unit can be replaced individually, or undamaged parts can be recovered, enhancing the maintainability of the reducer module.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is a schematic diagram of the structure of a two-stage drive harmonic reducer module according to an embodiment of the present invention;

[0022] Figure 2 for Figure 1 The diagram shown is an exploded view of the two-stage drive harmonic reducer module.

[0023] Figure 3 for Figure 1 The diagram shows a cross-sectional view of the two-stage drive harmonic reducer module.

[0024] Figure 4 for Figure 1 The diagram shows an exploded view of the fixed shaft of a two-stage harmonic reducer module.

[0025] Figure 5 for Figure 1 The diagram shown is an exploded view of the first stage reducer of the two-stage drive harmonic reducer module.

[0026] Figure 6 for Figure 1 The diagram shown is a structural schematic of the second stage reducer of the two-stage drive harmonic reducer module;

[0027] Figure 7 for Figure 1 The diagram shows an exploded view of the second stage reducer in a two-stage harmonic reducer module.

[0028] Figure label:

[0029] First stage reducer 100, first cavity 101, first wave generator 110, first clearance hole 111, first flexible wheel 120, first assembly part 121, first connecting area 1211, fifth connecting hole 1212, first transmission part 122, first rigid wheel 130, first crossed roller bearing 140, first outer ring 141, first inner ring 142, third connecting hole 1421, second clearance hole 1422, first flexible bearing 150, second stage reducer 200, second cavity 201, second wave generator 210, fourth stage reducer 100, second cavity 201, second wave generator 210, fourth wave generator 210, second wave generator 210, first ... Connecting hole 211, third clearance hole 212, second flexible wheel 220, second assembly part 221, second connecting area 2211, second transmission part 222, second rigid wheel 230, second crossed roller bearing 240, second outer ring 241, second inner ring 242, second flexible bearing 250, fixed shaft 300, shaft body 310, shaft connecting part 311, first connecting hole 312, first snap-fit ​​part 313, fourth clearance hole 314, shaft cover 320, second connecting hole 321, second snap-fit ​​part 322, fifth clearance hole 323. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of this invention, it should be understood that the orientation descriptions, such as axial, radial, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0032] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, and "above," "below," "within," etc. are understood to include the stated number. If "first," "second," etc. are used in the description, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0033] In the description of this invention, unless otherwise explicitly defined, terms such as "set", "install", and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0034] Currently, multi-stage harmonic reducers in the industrial field generally adopt a highly integrated one-piece structural design, where the first and second stage reducers 200 achieve deep structural integration by sharing core transmission components such as wave generators, flexible wheels, or rigid wheels. However, such integrated solutions are usually tailor-made for specific application scenarios (such as specific models of industrial robot joints, precision turntables, or aerospace actuators), requiring entirely new customized designs and dedicated production lines. This results in poor structural compatibility, severely limiting the scope of application and making it difficult to achieve universal adaptation across platforms and models. Especially in the R&D and prototyping stages of industrial robots, the demand for multi-stage harmonic reducers in a single batch is usually extremely small. If a lot of time is invested in designing new integrated reducers and organizing small-batch prototyping for such small-batch orders, not only will the R&D and production cycle be lengthy, but the inability to achieve economies of scale will also lead to a significant increase in unit costs, severely restricting the rapid iteration, cost control, and marketization of industrial robot products. Furthermore, the core component of the harmonic reducer—the flexure—is subjected to high-frequency periodic elastic deformation during operation. Working under alternating stress for extended periods, it is highly susceptible to material fatigue, leading to cracks or fractures, and ultimately causing functional failures or even complete damage to the entire reducer. Since most components of these customized integrated multi-stage harmonic reducers (such as flexures with specific tooth profiles) are non-standard parts, they cannot be directly purchased from the market after damage. Replacement parts must be custom-made from the original manufacturer, a time-consuming and costly process with extremely poor maintenance convenience. If the entire integrated multi-stage harmonic reducer assembly is scrapped and replaced with new parts, the procurement cost is high, and the recycling value of the remaining intact parts in the damaged assembly is almost zero, resulting in significant resource waste. From a life-cycle cost perspective, its maintainability and economic efficiency are both unsatisfactory.

[0035] Therefore, this embodiment discloses a two-stage harmonic reducer module, which improves the versatility and maintainability of the harmonic reducer module based on modular and reconfigurable technical concepts. Please refer to... Figure 1 and Figure 2 The two-stage harmonic reducer module of this embodiment includes a first-stage reducer 100, a second-stage reducer 200, and a fixed shaft 300. The first-stage reducer 100 achieves single-stage reduction, the second-stage reducer 200 achieves high-precision fine-tuning, and the fixed shaft 300 serves as a connection between the first-stage reducer 100 and the second-stage reducer 200. The various components and their interactions are described in detail below:

[0036] Please refer to Figure 2 and Figure 3The first-stage reducer 100 includes a first wave generator 110, a first flexible wheel 120, a first rigid wheel 130, and a first crossed roller bearing 140. The first flexible wheel 120 is sleeved between the first wave generator 110 and the first rigid wheel 130. The first flexible wheel 120 has external teeth, and the first rigid wheel 130 has internal teeth. The external teeth of the first flexible wheel 120 mesh with the internal teeth of the first rigid wheel 130. The first flexible wheel 120 is connected to the first inner ring 142 of the first crossed roller bearing 140, and the first rigid wheel 130 is connected to the first outer ring 141 of the first crossed roller bearing 140. In this way, the first crossed roller bearing 140 provides radial support and a torque transmission path for the first flexible wheel 120 and the first rigid wheel 130, as well as withstands the overturning moment during operation.

[0037] Please continue to refer to Figure 2 and Figure 3 The second-stage reducer 200 includes a second wave generator 210, a second flexible wheel 220, a second rigid wheel 230, and a second crossed roller bearing 240. The second flexible wheel 220 is sleeved between the second wave generator 210 and the second rigid wheel 230. The second flexible wheel 220 has external teeth, and the second rigid wheel 230 has internal teeth. The external teeth of the second flexible wheel 220 mesh with the internal teeth of the second rigid wheel 230. The second flexible wheel 220 is connected to the first outer ring 141 of the first crossed roller bearing 140 and the second outer ring 241 of the second crossed roller bearing 240. The second rigid wheel 230 is connected to the second inner ring 242 of the second crossed roller bearing 240. The design principle of the second crossed roller bearing 240 is the same as that of the first crossed roller bearing 140. The high rigidity and high precision characteristics of the crossed roller bearing ensure stability and low vibration during transmission, making it suitable for high-load and high-precision applications. By designing independent first crossed roller bearings 140 and second crossed roller bearings 240, the first-stage reducer 100 and the second-stage reducer 200 can form independent complete harmonic drive units, retaining both the separability for independent use and achieving integrated design for combined use. The second flexible wheel 220 is directly connected to the first outer ring 141 of the first crossed roller bearing 140, simplifying the connection structure between the first-stage reducer 100 and the second-stage reducer 200, thereby shortening the axial assembly distance between them and facilitating miniaturization and compact design requirements. Furthermore, this connection method reduces additional flanges or adapter components, helping to reduce the complexity of the reducer module and potential failure points, thus improving overall reliability.

[0038] Please refer to Figure 2 , Figure 3 and Figure 4The first end of the fixed shaft 300 is connected to the first inner ring 142 of the first crossed roller bearing 140, and the second end of the fixed shaft 300 is connected to the second wave generator 210. In this embodiment, the first inner ring 142 of the first crossed roller bearing 140 provides rigid support for the fixed shaft 300 and the first flexible wheel 120, enabling a mechanical connection between the first flexible wheel 120 and the fixed shaft 300. The second end of the fixed shaft 300 is connected to the second wave generator 210, thus achieving a mechanical connection between the first flexible wheel 120 and the second wave generator 210 through the first inner ring 142 of the first crossed roller bearing 140 and the fixed shaft 300.

[0039] Under standard operating conditions, the first flexible wheel 120 and the second wave generator 210 are in a fixed state. The first wave generator 110 of the first-stage reducer 100 is connected to the output shaft of the drive motor to transmit the torque of the drive motor. The first wave generator 110 causes the first flexible wheel 120 to undergo controlled elastic deformation, thereby causing the first flexible wheel 120 to mesh with the first rigid wheel 130 to drive the first rigid wheel 130 to rotate at a reduced speed. Since both the first rigid wheel 130 and the first flexible wheel 120 are connected to the first outer ring 141 of the first crossed roller bearing 140, the first rigid wheel 130 transmits power to the first flexible wheel 120 through the first outer ring 141 of the first crossed roller bearing 140, so that the first flexible wheel 120 rotates synchronously with the first rigid wheel 130 as the power input of the second-stage reducer 200. The first flexible wheel 120 meshes with the second rigid wheel 230 to transmit power, thereby outputting power through the second rigid wheel 230. Because the first-stage reducer 100 has a transmission configuration of a fixed first flexible gear 120, input from the first wave generator 110, and output from the first rigid gear 130, its transmission ratio range is relatively large (75~500), enabling single-stage reduction transmission. In contrast, the second-stage reducer 200 has a transmission configuration of a fixed second wave generator 210, input from the second flexible gear 220, and output from the second rigid gear 230. Its transmission ratio range is smaller (1.002~1.015), but it offers higher transmission accuracy, making it suitable for high-precision fine-tuning transmission. By combining the first-stage reducer 100 and the second-stage reducer 200, a combination of reduction transmission and high-precision fine-tuning transmission can be achieved.

[0040] Both the first-stage reducer 100 and the second-stage reducer 200 are structurally complete and independently operable harmonic reducers, detachably connected via a fixed shaft 300. The first-stage reducer 100 achieves single-stage reduction, while the second-stage reducer 200 boasts high transmission precision, enabling high-precision fine-tuning of the transmission. The two reducers can be used independently or in combination, significantly improving the versatility of the reducer module. If one stage reducer fails during long-term operation (e.g., due to fatigue fracture of the flexspline), only the damaged reducer needs to be disassembled and replaced, while the undamaged other stage reducer can be recycled as a spare part for subsequent repairs or other combinations. This significantly reduces spare parts inventory and maintenance costs, minimizes resource waste, and enhances the maintainability of the reducer module.

[0041] For example, the first-stage reducer 100 and the second-stage reducer 200 can be standard models available on the market, without the need for customization. If the first-stage reducer 100 is damaged, it can be directly disassembled and replaced, or the entire module can be replaced, and the intact second-stage reducer 200 can be removed from the old module as an independent spare part or used in a new module. Similarly, if only the second-stage reducer 200 is damaged, it can be replaced separately, and the still intact first-stage reducer 100 can be recycled and reused. As another example, in industrial robot applications, a robot typically requires multiple joint modules (e.g., a six-axis robot requires six), or a workstation may have multiple robots of the same model. Assuming that both multi-stage harmonic reducer modules (such as module #1 and module #2) adopt the two-stage transmission harmonic reducer module of this embodiment, if the first stage reducer 100 of module #1 is damaged and the second stage reducer 200 of module #2 is also damaged at the same time, thanks to the modular design and reconfigurable structural design of the reducer module, the intact second stage reducer 200 in module #1 and the intact first stage reducer 100 in module #2 can be disassembled and combined into a new multi-stage harmonic reducer module for continued use. At this time, only one new multi-stage harmonic reducer module needs to be replaced, instead of scrapping two old modules and using two new modules, which helps to reduce maintenance costs.

[0042] Please refer to Figure 5 , Figure 6 and Figure 7 The first flexible wheel 120 has a cup-shaped short cylindrical structure, and the second flexible wheel 220 has a top hat-shaped short cylindrical structure. Please refer to... Figure 5The first flexible wheel 120 includes a first mounting portion 121 and a first transmission portion 122. The first transmission portion 122 is a thin-walled annular structure. The first end of the first transmission portion 122 is connected to the first mounting portion 121, and the second end of the first transmission portion 122 is provided with external teeth (tooth profile not shown in the figure) that mesh with the first rigid wheel 130. The first connection area 1211 connecting the first mounting portion 121 and the first crossed roller bearing 140 is located radially inside the first transmission portion 122, that is, the first connection area 1211 is closer to the center of the first flexible wheel 120 relative to the first transmission portion 122, so that the first flexible wheel 120 can be mounted on the first inner ring 142 of the first crossed roller bearing 140. Please refer to... Figure 6 and Figure 7 The second flexible wheel 220 includes a second mounting part 221 and a second transmission part 222. The second transmission part 222 is also a thin-walled annular structure. The first end of the second transmission part 222 is connected to the second mounting part 221. The second end of the second transmission part 222 is provided with external teeth (tooth profile not shown in the figure) that mesh with the second rigid wheel 230. Unlike the first flexible wheel 120, the second connection area 2211 of the second mounting part 221 of the second flexible wheel 220 and the second crossed roller bearing 240 is located on the radial outer side of the second transmission part 222. That is, the second transmission part 222 is closer to the center of the second flexible wheel 220 than the second connection area 2211, so that the second flexible wheel 220 can be installed on the first outer ring 141 of the first crossed roller bearing 140 and the second outer ring 241 of the second crossed roller bearing 240, thereby rotating synchronously with the first rigid wheel 130. It is worth mentioning that the second connecting area 2211 of the second flexible wheel 220 is provided with a thickened structure, so that there is a small gap between the second flexible wheel 220 and the first inner ring 142 of the first crossed roller bearing 140, avoiding motion interference between the two. It should be noted that in this embodiment, the outer diameter of the second mounting part 221 of the second flexible wheel 220, the outer diameter of the first crossed roller bearing 140, and the outer diameter of the second crossed roller bearing 240 are all equal.

[0043] Please refer to Figure 2 , Figure 3 and Figure 6 The first-stage reducer 100 is provided with a first cavity 101, and the second-stage reducer 200 is provided with a second cavity 201. The first cavity 101 and the second cavity 201 form an internal assembly cavity, and the fixed shaft 300 is located in the internal assembly cavity (e.g., Figure 3(As shown in the middle, marked P1). For example, the first flexible wheel 120 has a cup-shaped short cylindrical structure. The axial width of the first flexible wheel 120 is approximately equal to half the axial width of the first stage reducer 100. The assembly position between the first flexible wheel 120 and the first inner ring 142 of the first crossed roller bearing 140 is approximately in the middle of the first stage reducer 100. Thus, machining the first cavity 101 on the side of the first crossed roller bearing 140 opposite to the first flexible wheel 120 can both reduce weight and reduce the thickness of the first inner ring 142 of the first crossed roller bearing 140, so that threaded fasteners (such as screws or bolts) can be inserted between the first flexible wheel 120 and the first crossed roller bearing 140 to achieve a fixed connection between the two. The second flexible wheel 220 has a top hat-shaped short cylindrical structure. The second connecting area 2211 of the second flexible wheel 220 is connected to the axial surface of the second outer ring 241 of the second crossed roller bearing 240. The second inner ring 242 of the second crossed roller bearing 240 has a hollow ring structure. The second transmission part 222 of the second flexible wheel 220 is sleeved on the inner side of the second inner ring 242 of the second crossed roller bearing 240. The second wave generator 210 has a flat and lightweight structure. The axial width of the second wave generator 210 is smaller than the axial width of the second flexible wheel 220. The installation position of the second wave generator 210 is adapted to the position of the external teeth of the second flexible wheel 220. After assembly, a second cavity 201 of a certain depth is formed between the second wave generator 210 and the second assembly part 221 of the second flexible wheel 220. After the first-stage reducer 100 and the second-stage reducer 200 are assembled, the second assembly part 221 of the second flexible wheel 220 is connected to the first outer ring 141 of the first crossed roller bearing 140 and the second outer ring 241 of the second crossed roller bearing 240, respectively. The first cavity 101 and the second cavity 201 form an internal assembly cavity. The fixed shaft 300 is installed in the internal assembly cavity, which can effectively shorten the overall axial width of the reducer module and meet the requirements of miniaturization and compact design.

[0044] Please refer to Figure 4The fixed shaft 300 includes a shaft body 310 and a shaft cover 320. The shaft body 310 has a hollow structure. The first end of the shaft body 310 is provided with a shaft connecting part 311, which is provided with a plurality of first connecting holes 312. The second end of the shaft body 310 is provided with a plurality of first snap-fit ​​parts 313. The shaft cover 320 is provided with a plurality of second connecting holes 321 and a plurality of second snap-fit ​​parts 322. The shaft connecting part 311 is connected to the first inner ring 142 of the first crossed roller bearing 140 through the first connecting holes 312. The shaft body 310 and the shaft cover 320 are connected by the first snap-fit ​​parts 313 and the second snap-fit ​​parts 322. The shaft cover 320 is connected to the second wave generator 210 through the second connecting holes 321. For example, the shaft body 310 is a hollow cylindrical structure. The shaft connecting portion 311 is located at the first end of the shaft body 310, and the shaft connecting portion 311 is located radially inside the side wall of the shaft body 310. That is, the shaft connecting portion 311 is closer to the axis than the side wall of the shaft body 310. The second end of the shaft body 310 is machined with four notches serving as the first locking portion 313. Correspondingly, the shaft cover 320 is machined with four radial protrusions serving as the second locking portion 322. The shaft body 310 and the shaft cover 320 achieve circumferential positioning through the cooperation of the first locking portion 313 and the second locking portion 322, that is, to prevent the shaft body 310 and the shaft cover 320 from rotating relative to each other around the axis.

[0045] Please refer to Figure 5 The first inner ring 142 of the first crossed roller bearing 140 is provided with a plurality of third connecting holes 1421, and the first connecting hole 312 is adapted to the third connecting hole 1421. Please refer to... Figure 6 and Figure 7 The second wave generator 210 is provided with multiple fourth connection holes 211, and the second connection hole 321 is adapted to the fourth connection holes 211. The first flexible wheel 120 is provided with a fifth connection hole 1212. Please refer to the above. Figures 4 to 7During assembly, the first threaded fastener is inserted into the first connecting hole 312, the third connecting hole 1421, and the fifth connecting hole 1212 from the middle position of the shaft body 310 of the fixed shaft 300, thereby locking the first flexible wheel 120 and the shaft connection part 311 of the fixed shaft 300 onto the first inner ring 142 of the first crossed roller bearing 140. The shaft body 310 and the shaft cover 320 of the fixed shaft 300 are assembled through the cooperation of the first snap-fit ​​part 313 and the second snap-fit ​​part 322, thus assembling the second stage reducer 2. The second wave generator 210 is assembled with the first-stage reducer 100, and the first outer ring 141 of the first crossed roller bearing 140, the second flexible wheel 220, and the second outer ring 241 of the second crossed roller bearing 240 are locked together using a second threaded fastener, thus achieving a fixed connection between the first-stage reducer 100 and the second-stage reducer 200. Then, a third threaded fastener is inserted into the fourth connecting hole 211 and the second connecting hole 321 to connect the second wave generator 210 to the shaft cover 320 of the fixed shaft 300. In this way, the fixed shaft 300 can be hidden inside the first-stage reducer 100 and the second-stage reducer 200, eliminating the need for additional axial connection structures. This helps to shorten the overall axial width of the reducer module, resulting in a smaller width-to-diameter ratio.

[0046] The first wave generator 110 is provided with a first clearance hole 111, the first inner ring 142 of the first crossed roller bearing 140 is provided with a second clearance hole 1422, the second wave generator 210 is provided with a third clearance hole 212, the shaft connection part 311 of the shaft body 310 is provided with a fourth clearance hole 314, and the middle part of the shaft cover 320 is provided with a fifth clearance hole 323. The first clearance hole 111, the second clearance hole 1422, the third clearance hole 212, the fourth clearance hole 314 and the fifth clearance hole 323 are located on the same axis and form a clearance channel. The clearance channel can be used for wiring. Through integrated wiring design, it is beneficial to reduce interference from external cables and improve the neatness and reliability of wiring.

[0047] The width-to-diameter ratio of the first-stage reducer 100 is 0.29 (the width-to-diameter ratio is equal to the ratio of diameter to axial width), and the width-to-diameter ratio of the second-stage reducer 200 is 0.20. This means that each single-stage reducer has a relatively small width-to-diameter ratio, exhibiting a flattened structural feature. This effectively reduces the axial space occupied, making it suitable for miniaturized and compact designs where axial space is strictly limited. When the first-stage reducer 100 and the second-stage reducer 200 are combined into a two-stage harmonic reducer module as described in this embodiment, the overall width-to-diameter ratio remains within the range of 0.46 to 0.47, maintaining good compactness and not occupying excessive axial space, thus continuing to meet the miniaturization requirements of applications such as industrial robot joints.

[0048] Please refer to Figure 5 and Figure 7A first flexible bearing 150 is installed between the first wave generator 110 and the first flexible wheel 120, and a second flexible bearing 250 is installed between the second wave generator 210 and the second flexible wheel 220. The outer ring of the first flexible bearing 150 fits against the inner wall of the first flexible wheel 120, and the inner ring of the first flexible bearing 150 is connected to the cam of the first wave generator 110. This avoids direct metal-to-metal contact and sliding friction between the first wave generator 110 and the first flexible wheel 120, transforming sliding friction into rolling friction within the first flexible bearing 150. This significantly reduces friction loss, temperature rise, and wear, giving the first-stage reducer 100 a longer service life and higher transmission efficiency. The design principle of the second flexible bearing 250 is the same as that of the first flexible bearing 150, and will not be described further here.

[0049] This embodiment also provides a joint module, including the aforementioned two-stage harmonic reducer module. Details of the two-stage harmonic reducer module can be found above and will not be repeated here. Both the first-stage reducer 100 and the second-stage reducer 200 are structurally complete and independently operable harmonic reducers, detachably connected via a fixed shaft 300. The first-stage reducer 100 performs single-stage reduction, while the second-stage reducer 200 possesses high transmission accuracy, enabling high-precision fine-tuning of the transmission. The two reducers can be used independently or in combination, significantly improving the versatility of the reducer module. If one stage reducer is damaged, the faulty unit can be replaced individually or the undamaged part can be recovered, enhancing the maintainability of the reducer module.

[0050] This embodiment also provides a robot, including the aforementioned joint module. The details of the joint module are as described above and will not be repeated here. Both the first-stage reducer 100 and the second-stage reducer 200 are structurally complete and independently operable harmonic reducers, detachably connected via a fixed shaft 300. The first-stage reducer 100 performs single-stage reduction, while the second-stage reducer 200 possesses high transmission accuracy, enabling high-precision fine-tuning of the transmission. The two reducers can be used independently or in combination, significantly improving the versatility of the reducer module. If a reducer is damaged, the faulty unit can be replaced individually or the undamaged part can be recovered, enhancing the maintainability of the reducer module.

[0051] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A two-stage transmission harmonic reducer module, characterized by, Comprise: The first stage reducer (100) comprises a first wave generator (110), a first flexible gear (120), a first rigid gear (130) and a first cross-roller bearing (140), the first flexible gear (120) is sleeved between the first wave generator (110) and the first rigid gear (130), and the outer teeth of the first flexible gear (120) are in meshing connection with the inner teeth of the first rigid gear (130), the first flexible gear (120) is connected with the first inner ring (142) of the first cross-roller bearing (140), and the first rigid gear (130) is connected with the first outer ring (141) of the first cross-roller bearing (140); The second stage reducer (200) comprises a second wave generator (210), a second flexible gear (220), a second rigid gear (230) and a second cross-roller bearing (240), the second flexible gear (220) is sleeved between the second wave generator (210) and the second rigid gear (230), and the outer teeth of the second flexible gear (220) are in meshing connection with the inner teeth of the second rigid gear (230), the second flexible gear (220) is connected with the first outer ring (141) of the first cross-roller bearing (140) and the second outer ring (241) of the second cross-roller bearing (240) respectively, and the second rigid gear (230) is connected with the second inner ring (242) of the second cross-roller bearing (240); A fixed shaft (300) has a first end connected to a first inner ring (142) of the first cross-roller bearing (140) and a second end connected to the second wave generator (210); the fixed shaft (300) comprises a shaft body (310) and a shaft cover (320); the shaft body (310) is a hollow structure, the shaft body (310) is provided with a shaft connecting part (311) at the first end, the shaft connecting part (311) is provided with a plurality of first connecting holes (312), the shaft body (310) is provided with a plurality of first clamping parts (313) at the second end, the shaft cover (320) is provided with a plurality of second connecting holes (321) and a plurality of second clamping parts (322), the shaft connecting part (311) is connected to the first inner ring (142) of the first cross-roller bearing (140) through the first connecting hole (312), the shaft body (310) and the shaft cover (320) are connected through the first clamping part (313) and the second clamping part (322), and the shaft cover (320) is connected to the second wave generator (210) through the second connecting hole (321); the first inner ring (142) of the first cross-roller bearing (140) is provided with a plurality of third connecting holes (1421), the first connecting hole (312) is adapted to the third connecting hole (1421), the second wave generator (210) is provided with a plurality of fourth connecting holes (211), and the second connecting hole (321) is adapted to the fourth connecting hole (211); the first wave generator (110) is provided with a first avoidance hole (111), the first inner ring (142) of the first cross-roller bearing (140) is provided with a second avoidance hole (1422), the second wave generator (210) is provided with a third avoidance hole (212), the shaft connecting part (311) of the shaft body (310) is provided with a fourth avoidance hole (314), and the middle part of the shaft cover (320) is provided with a fifth avoidance hole (323); the first avoidance hole (111), the second avoidance hole (1422), the third avoidance hole (212), the fourth avoidance hole (314) and the fifth avoidance hole (323) are located on the same axis and form an avoidance channel.

2. The dual-stage transmission harmonic reducer module of claim 1, wherein, The first flexible gear (120) is a cup-shaped short cylinder structure, and the second flexible gear (220) is a top hat-shaped short cylinder structure.

3. Double-stage transmission harmonic reducer module according to claim 1 or 2, characterized in that The first-stage reducer (100) is provided with a first concave cavity (101), the second-stage reducer (200) is provided with a second concave cavity (201), the first concave cavity (101) and the second concave cavity (201) form an internal assembly cavity, and the fixed shaft (300) is located in the internal assembly cavity.

4. The dual-stage transmission harmonic reducer module of claim 1, wherein, The width-to-diameter ratio of the first-stage reducer (100) is 0.29, and the width-to-diameter ratio of the second-stage reducer (200) is 0.

20.

5. The dual-stage transmission harmonic reducer module of claim 1, wherein, A first flexible bearing (150) is installed between the first wave generator (110) and the first flexspline (120), and a second flexible bearing (250) is installed between the second wave generator (210) and the second flexspline (220).

6. A joint module, characterized in that A double-stage transmission harmonic reducer module as claimed in any one of claims 1 to 5.

7. A robot, characterized in that A joint module as claimed in claim 6.

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