deceleration device

Abstract

Embodiments of the present disclosure provide a speed reduction device. The speed reduction device comprises: an input gear shaft coupled to an output end of a power device; a planetary reduction assembly comprising a planetary gear assembly coupled to the input gear shaft and a carrier coupled to the planetary gear assembly and adapted to transmit rotation of the input gear shaft to the carrier after a first stage of speed reduction; and a harmonic reduction assembly comprising a harmonic generator fixedly coupled to the carrier, a flexspline coupled to the harmonic generator, and a rigid wheel engaged with the flexspline, the rigid wheel being coupled to an external component such that the rigid wheel drives the external component to rotate at an output speed after a second stage of speed reduction. In this way, the speed reduction device is compact in structure and has a large speed reduction ratio capability.

Description

Technical Field

[0001] The exemplary embodiments disclosed herein generally relate to the field of robotics, and particularly to a deceleration device for a robot. Background Technology

[0002] Speed ​​reducers are typically located between the power unit and the load, serving to match the rotational speed and torque. As a core component of a robot, the speed reducer needs to withstand a certain load when the robot performs a task and amplify the relatively small torque output from the power unit proportionally to provide sufficient torque for the robot's joints to drive the load. Therefore, speed reducer design plays a crucial role in the robot's transmission system. Summary of the Invention

[0003] In a first aspect of this disclosure, a speed reduction device is provided. The speed reduction device includes: an input gear shaft coupled to the output end of a power unit; a planetary speed reduction assembly including a planetary gear assembly coupled to the input gear shaft and a planet carrier coupled to the planetary gear assembly, and adapted to transmit the rotation of the input gear shaft to the planet carrier after a first-stage speed reduction; and a harmonic speed reduction assembly including a harmonic generator fixedly coupled to the planet carrier, a flexible gear coupled to the harmonic generator, and a rigid gear meshing with the flexible gear, the rigid gear being coupled to an external component such that the rigid gear drives the external component to rotate at an output speed after a second-stage speed reduction.

[0004] In some embodiments, the planetary gear assembly includes: a plurality of first gears equidistantly arranged in the circumferential direction of the input gear shaft for meshing with the input gear shaft; and a plurality of second gears coaxially arranged on one side of the plurality of first gears in the axial direction and rotating with the first gears, wherein the outer diameter of each of the plurality of second gears is smaller than the outer diameter of the corresponding first gear and the module is different from the module of the corresponding first gear, and wherein the planetary reduction assembly further includes: an internal gear ring arranged on the outer side of the planet carrier in the radial direction and meshing with the plurality of second gears.

[0005] In some embodiments, the internal gear ring includes: an internal gear ring body portion having a hollow cylindrical structure; an internal gear ring flange portion extending radially outward from an end of the internal gear ring body portion away from the planet carrier in the axial direction; a flange portion extending radially inward from an end of the internal gear ring body portion near the planet carrier in the axial direction; and a coupling portion formed on the radially inner side of the flange portion and protruding from the flange portion in the axial direction to couple to a side of the harmonic reduction assembly near the planetary reduction assembly in the axial direction, and the inner circumferential surface of the coupling portion has internal teeth that mesh with a plurality of second gears.

[0006] In some embodiments, the planetary reduction assembly further includes: a plurality of drive shafts, each of the plurality of drive shafts passing through a corresponding second gear and a first gear in an axial direction, and each drive shaft being coupled to a harmonic generator at one end in the axial direction and to a planet carrier at the other end.

[0007] In some embodiments, the planetary carrier includes a first hollow region and a plurality of first coupling structures arranged around the first hollow region.

[0008] In some embodiments, the harmonic generator includes an elliptical body, the elliptical body including a first hollow region and a plurality of second coupling structures uniformly arranged around the first hollow region, the plurality of second coupling structures being arranged to align with a plurality of first coupling structures of the planetary carrier to couple the harmonic generator to the planetary carrier.

[0009] In some embodiments, the harmonic deceleration assembly further includes a thin-walled bearing coupled radially between the harmonic generator and the flexure.

[0010] In some embodiments, the flex wheel includes: a flex wheel gear body portion coupled to a thin-walled bearing; a flex wheel flange portion extending radially outward from one end of the flex wheel gear body portion in the axial direction and disposed on the side of the inner gear flange portion close to the harmonic generator in the axial direction; and a first external tooth formed on the outer peripheral surface of the flex wheel gear body portion in the radial direction.

[0011] In some embodiments, the rigid wheel includes: a first internal tooth that meshes with a first external tooth, and the number of teeth of the first internal tooth is greater than the number of teeth of the first external tooth.

[0012] In some embodiments, the speed reduction device further includes a crossed roller bearing coupled radially between the flexure flange of the rigid wheel and the flexure wheel to allow the rigid wheel to rotate relative to the flexure wheel.

[0013] In some embodiments, the speed reduction device further includes: a first transmission bearing coupled radially to the input gear shaft and the planetary carrier; and a second transmission bearing coupled radially to the input gear shaft and the harmonic generator.

[0014] In some embodiments, the speed reduction device further includes a first bushing and a second bushing, respectively disposed at both ends of the drive shaft in the axial direction.

[0015] It should be understood that the content described in this content section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0016] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0017] Figure 1 A cross-sectional view of a speed reduction device according to an embodiment of the present disclosure is shown;

[0018] Figure 2 An exploded perspective view of a speed reduction device according to an embodiment of the present disclosure is shown; and

[0019] Figure 3 A top view of a deceleration device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0020] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0021] It should be noted that the headings of any section / subsection provided herein are not limiting. Various embodiments are described throughout this document, and embodiments of any type may be included under any section / subsection. Furthermore, embodiments described in any section / subsection may be combined in any way with any other embodiments described in the same section / subsection and / or different sections / subsections.

[0022] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". Other explicit and implicit definitions may also be included below. The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0023] As mentioned earlier, reducer design plays a crucial role in robot transmission systems. Conventional planetary reducers have small single-stage reduction ratios. Increasing the reduction ratio requires multiple stages of gears connected in series, resulting in a lengthy structure that is inconvenient for robot integration. Conventional harmonic reducers, while compact in structure, require high-precision machining to achieve the tooth number difference between the flexible and rigid gears. However, existing machining tools face technical difficulties and cost limitations in manufacturing gears with high tooth number differences. This means that to achieve a larger reduction ratio, the outer diameter of the reducer needs to be increased. Consequently, the reducer's size and weight increase, failing to meet the requirements of lightweight robot design.

[0024] To address, or at least partially address, the aforementioned problems or other potential issues of conventional speed reduction devices, embodiments of this disclosure provide a speed reduction device. According to the embodiments of this disclosure, a two-stage speed reduction is achieved through the design of planetary and harmonic speed reduction components, resulting in a compact structure, flat volume, high torque density, and a reduction ratio exceeding 1000. Furthermore, due to its flat and compact structure, the reducer meets the heavy-load requirements of the robot without occupying excessive space, thus allowing for more flexible internal robot design. Furthermore, the reducer also features a hollow structure design, facilitating the routing of robot electrical wiring harnesses through the hollow structure and avoiding the need for large-angle bends when routing electrical wiring harnesses outside the reducer, thereby improving the reliability of the robot's electrical wiring harness layout.

[0025] The following will combine Figures 1 to 3 The following describes an example structure of the speed reduction device. According to embodiments of this disclosure, the speed reduction device generally includes at least an input gear shaft 1, a planetary reduction assembly, and a harmonic reduction assembly. The input gear shaft 1 is coupled to the output end of a power unit for transmitting power from the power unit to the planetary reduction assembly and the harmonic reduction assembly. The input gear shaft 1 includes a hollow structure along its axial direction, thereby allowing electrical wiring harnesses to pass through the hollow structure and avoiding large-angle bending problems that would occur when the electrical wiring harness is routed outside the speed reduction device.

[0026] The planetary reduction assembly includes a planetary gear assembly 2 and a planet carrier 3 to form a single-stage reduction structure. The planetary gear assembly 2 is coupled to the input gear shaft 1. The gear on the input gear shaft 1 serves as the sun gear of the planetary reduction device, transmitting power from the power unit to the planetary gear assembly 2, causing the planetary gear assembly 2 to rotate around the sun gear. The planet carrier 3 is coupled to and supports the planetary gear assembly 2. Driven by the planetary gear assembly 2, the planet carrier 3 can rotate around the input gear shaft 1. In this way, by transmitting the rotation of the input gear shaft 1 to the planet carrier 3 after a single-stage reduction, the rotational speed of the planet carrier 3 relative to the input gear shaft 1 is reduced.

[0027] The harmonic reduction assembly includes a harmonic generator 4, a flexible gear 5, and a rigid gear 6 to form a two-stage reduction structure. The harmonic generator 4 is fixedly coupled to the planetary carrier 3, and the rotation of the planetary carrier 3 drives the harmonic generator 4 to rotate. In some embodiments, the harmonic generator 4 may be elliptical and have a major axis and a minor axis.

[0028] The flexible wheel 5 is capable of elastic deformation and is coupled to the harmonic generator 4. Under the action of the harmonic generator 4, the flexible wheel 5 can generate periodic elastic deformation. The flexible wheel 5 can mesh with the rigid wheel 6, and as the harmonic generator 4 rotates, the elastic deformation of the flexible wheel 5 continuously changes, causing the meshing position of the flexible wheel 5 and the rigid wheel 6 to change periodically, forming a continuous simple harmonic waveform motion. In some embodiments, the rigid wheel 6 can be a fixed end, and the flexible wheel 5 can be an output end. In other embodiments, the flexible wheel 5 can be a fixed end, and the rigid wheel 6 can be an output end. There is a difference in the number of teeth between the flexible wheel 5 and the rigid wheel 6, which significantly reduces the rotational speed of the rigid wheel 6 relative to the flexible wheel 5, thereby achieving further deceleration.

[0029] The rigid wheel 6 can be coupled to external components. The rotation of the harmonic generator 4 drives the flexible wheel 5 to rotate, and simultaneously, the flexible wheel 5 meshes with the rigid wheel 6, so that the rigid wheel 6 drives the external components to rotate at the output speed after two-stage reduction, thereby further reducing the speed of the external components relative to the speed of the planetary carrier 3. In this way, the planetary reduction assembly and the harmonic reducer assembly are combined, achieving a larger reduction ratio through multi-stage reduction while maintaining a compact structure.

[0030] In some embodiments, the planetary gear assembly 2 may include a plurality of first gears 21 and a plurality of second gears 22. The plurality of first gears 21 are evenly distributed around the circumference of the input gear shaft 1 and are coaxially fixedly arranged with their corresponding second gears 22, thereby forming a double-gear structure. This double-gear structure allows the two gears to achieve multi-stage transmission within a smaller space, achieving a large transmission ratio while maintaining the compactness of the entire reduction device. Simultaneously, this double-gear structure reduces the torque requirement of the input gear shaft 1, allowing the input gear shaft 1 to have a hollow structure, thus facilitating the passage of electrical wiring harnesses through the hollow structure.

[0031] Under the power input from the input gear shaft 1, multiple first gears 21 simultaneously mesh with the input gear shaft 1, and multiple second gears 22 rotate around the input gear shaft 1 along with the multiple first gears 21. In this way, the multiple first gears 21 and the multiple second gears 22 constitute a planetary gear assembly rotating around the sun gear. In some embodiments, the outer diameter of each second gear 22 may be different from the outer diameter of the corresponding first gear 21, and the module of each second gear may be different from the module of the corresponding first gear 21. For example, the outer diameter of each second gear 22 may be smaller than the outer diameter of the corresponding first gear 21, thereby achieving different transmission ratios.

[0032] In some embodiments, the planetary reduction assembly may further include multiple drive shafts 7. Each drive shaft 7 passes axially through a corresponding second gear 22 and first gear 21, allowing the second gear 22 and first gear 21 to rotate about the axis of the drive shaft 7. Both ends of each drive shaft 7 are coupled to the harmonic generator 4 and the planet carrier 3, respectively. In this way, the drive shaft 7 not only enables the first gear 21 and second gear 22 to rotate about themselves, but also drives the planet carrier 3 and the harmonic generator 4 to rotate about the input gear shaft 1.

[0033] In some embodiments, the planetary reduction assembly may further include an internal gear ring 23. The internal gear ring 23 is arranged on the outer side of the planet carrier 3 in the radial direction and meshes with a plurality of second gears 22. In some embodiments, the internal gear ring 4 may be kept fixed so that the plurality of second gears 22 rotate on the inner circumferential surface of the internal gear ring. In this way, driven by the input gear shaft, the plurality of second gears 22 not only rotate around the drive shaft 7, but also revolve together with the drive shaft 7 around the axis of the input gear shaft 1 on the inner circumferential surface of the internal gear ring 4, thereby causing the drive shaft 7 to rotate the planet carrier 7 around the input gear shaft 1. In this way, the rotation of the input gear shaft 1 is transmitted to the planet carrier 3 to achieve first-stage reduction.

[0034] In some embodiments, the internal gear ring 23 may include an internal gear ring body portion 231, an internal gear ring flange portion 232, a flange portion 233, and a coupling portion 234. The internal gear ring body portion 231 has a hollow cylindrical structure, so that components such as the planet carrier 3, the planet gear assembly 2, and the gear input shaft 1 are at least partially arranged within the hollow cylindrical structure.

[0035] The internal gear ring flange 232 extends radially outward from one end of the cylindrical internal gear ring body 231. As a support and fixing structure, the internal gear ring flange 232 is positioned axially away from the planet carrier 3. The flange 233 extends radially inward from the other end of the cylindrical internal gear ring body 231 and is located axially closer to the planet carrier 3. In this manner, the internal gear ring flange 231 and flange 233 not only provide support and fixation but also enhance the structural stability of the entire internal gear ring, enabling it to remain stable under high loads and complex operating conditions, reducing deformation and wear, thereby improving the overall reliability of the reducer.

[0036] The coupling portion 234 is radially inner to the flange portion 233 and protrudes axially from the flange portion 233 to couple the harmonic generator 4 to the planetary carrier 3. In some embodiments, the coupling portion 234 is clearance-fitted with the harmonic generator 4 in the axial direction. In some alternative or additional embodiments, the coupling portion 234 is clearance-fitted with the harmonic generator 4 in the radial direction. In this way, the clearance fit maintains a certain space between the harmonic generator 4 and the planetary carrier 3, reducing direct contact and thus reducing friction.

[0037] The inner circumferential surface of the coupling part 234 has internal teeth. Multiple second gears 22 mesh with these internal teeth. Driven by the first gear 21, the multiple second gears 22 not only rotate around the drive shaft 7, but also drive the drive shaft 7 to revolve around the axis of the input gear shaft 1 on the inner circumferential surface of the internal gear ring 4. This causes the drive shaft 7 to rotate the planetary carrier 3 around the input gear shaft 1. In this way, through the meshing of the internal gear ring 23 with the planetary gear assembly, the rotational motion of the input gear shaft 1 is converted into the rotational and revolving motion of the planetary gear assembly, thereby driving the planetary carrier 3 to rotate to achieve first-stage speed reduction.

[0038] In some embodiments, the planetary carrier 3 may include a first hollow region. The input gear shaft 1 passes through the first hollow region and is coupled to the harmonic generator 4. The planetary carrier 3 may also include a plurality of first coupling structures. The plurality of first coupling structures are evenly arranged around the first hollow region, thereby coupling the planetary carrier 3 to the harmonic generator 4.

[0039] In some embodiments, the harmonic generator 4 may include an elliptical body. The elliptical body includes a second hollow region to facilitate the passage of electrical wiring harnesses. The electrical wiring harness passes through the hollow structure of the input gear shaft 1, through the second hollow region of the elliptical body, and exits. In this way, the hollow structure design of the reduction gear makes full use of the internal space of the reduction gear, avoids the problem of large-angle bending of the electrical wiring harness when it is routed outside the reduction gear, and improves the reliability of the overall robot electrical wiring harness layout.

[0040] In some embodiments, the elliptical body may further include a plurality of second coupling structures uniformly arranged around the second hollow region. The plurality of second coupling structures are aligned with a plurality of first coupling structures of the planetary carrier 3 to couple the harmonic generator 4 to the planetary carrier 3. In some embodiments, the first and second coupling structures may include connectors. For example, the connector may include bolts. After passing through the first and second coupling structures, the bolts secure the harmonic generator 4 and the planetary carrier 3 together. In some alternative or additional embodiments, the first and second coupling structures may further include engaging structures. For example, the engaging structure may include protrusions or grooves. The first and second coupling structures are positioned by the engagement of protrusions and grooves, achieving a fixed connection between the harmonic generator 4 and the planetary carrier 3.

[0041] In some embodiments, the harmonic deceleration assembly may further include a thin-walled bearing 8. The thin-walled bearing 8 includes an inner bearing ring and an outer bearing ring. In the radial direction, the inner bearing ring is coupled to the outer periphery of an elliptical body. The shape of the inner bearing ring is supported by the elliptical body, forming an elliptical shape. As the elliptical body rotates, the outer bearing ring undergoes periodic elliptical deformation under the action of the elliptical body. In the radial direction, the outer bearing ring is coupled to a flexible wheel 5, causing the flexible wheel 5 to undergo periodic elliptical deformation. In this way, the thin-walled bearing 8 is coupled to the harmonic generator 4 via its inner ring and to the flexible wheel 5 via its outer ring, thereby transmitting the rotational motion of the harmonic generator 4 to the flexible wheel 5 to achieve power transmission.

[0042] In some embodiments, the flexible gear 5 may include a flexible gear ring body, a flexible gear flange, and a first external tooth. The flexible gear ring body is coupled to the outer ring of the thin-walled bearing 8. The flexible gear ring body can undergo elastic deformation, and as the elliptical body rotates, the flexible gear ring body can produce periodic elliptical deformation. The flexible gear flange extends radially outward from one end of the flexible gear ring body in the axial direction and is coupled to the inner gear ring flange. That is, the flexible gear 5 is fixed to the inner gear ring 4 as a fixed end, and the rigid gear 6 is rotatable relative to the flexible gear 5 as an output end. The outer circumferential surface of the flexible gear ring body in the radial direction has a first external tooth for meshing with the first internal tooth of the rigid gear 6, which will be mentioned later.

[0043] In some embodiments, the rigid wheel 6 may include a first internal tooth. The first internal tooth is formed on the inner circumferential surface of the rigid wheel 6 and meshes with a first external tooth, thereby enabling the flexible wheel 5 to rotate relative to the rigid wheel 6. When the harmonic generator 4 rotates, the flexible wheel 5 undergoes periodic elastic deformation under the action of the harmonic generator 4. In the direction of the major axis of the elliptical body of the harmonic generator 4, the flexible wheel 5 meshes with the rigid wheel 6, and in the direction of the minor axis of the elliptical body, the flexible wheel 5 disengages from the rigid wheel 6. The meshing position of the flexible wheel 5 and the rigid wheel 6, from engagement, engagement, disengagement to disengagement, forms a continuous simple harmonic waveform motion.

[0044] In some embodiments, the number of teeth on the first internal gear can be greater than the number of teeth on the first external gear; that is, the number of teeth on the flexible gear 5 is less than the number of teeth on the rigid gear 6, and there is a difference in the number of teeth between the flexible gear 5 and the rigid gear 6. For example, the number of teeth on the first internal gear can be 1 to 3 more than the number of teeth on the first external gear (i.e., the difference in the number of teeth is 1 to 3). Since the flexible gear 5 has 1 to 3 fewer teeth than the rigid gear 6, when the flexible gear 5 is fixed, for every revolution of the harmonic generator 4, the relative motion of the flexible gear 5 with respect to the rigid gear 6 is 1 to 3 teeth, causing the rigid gear 6 to rotate 1 to 3 teeth. In this way, the difference in the number of teeth makes the output speed of the rigid gear 6 significantly lower than the input speed of the harmonic generator 4, thereby achieving a high reduction ratio.

[0045] In some embodiments, the first-stage reduction ratio of the gear reduction assembly can reach 10, and the second-stage reduction ratio of the harmonic reduction assembly can reach 80 to 160. Therefore, the total reduction ratio of the reduction device can reach 800 to 1600, thus achieving the transmission requirement of high reduction ratio.

[0046] In some embodiments, the reduction gear may further include a crossed roller bearing 9. The crossed roller bearing 9 is radially coupled between the rigid wheel 6 and the flexure flange of the flexible wheel 5 to allow the rigid wheel 6 to rotate relative to the flexure 5. Specifically, the crossed roller bearing 9 includes an inner ring and an outer ring. The inner ring is coupled to the rigid wheel 6, and the outer ring is coupled to the flexure flange of the flexible wheel 5. In this manner, the rollers inside the crossed roller bearing are arranged at 90-degree intervals, resulting in a compact structure capable of simultaneously withstanding loads in multiple directions, and providing high rotational accuracy and stiffness within a small space. Therefore, arranging the crossed roller bearing between the flexure 5 and the rigid wheel 6 saves space while significantly improving the system's load capacity, accuracy, and stability.

[0047] In some embodiments, the reduction gear may further include a first transmission bearing and a second transmission bearing. The first and second transmission bearings are respectively arranged on the outer periphery of the input gear shaft 1. The first transmission bearing is arranged between the input gear shaft 1 and the planetary carrier 3, and the second transmission bearing is arranged between the input gear shaft 1 and the harmonic generator 4. In this manner, the transmission bearings can withstand radial and axial loads, ensuring stable operation of the input gear shaft 1, planetary carrier 3, and harmonic generator 4 under high load conditions, while also reducing friction and improving transmission accuracy.

[0048] In some embodiments, the reduction gear may further include a first bushing and a second bushing. The first bushing and the second bushing are respectively arranged at both ends of the drive shaft 7 in the axial direction. In some embodiments, the first bushing and the second bushing are generally U-shaped and each includes a connecting portion and a support portion extending radially outward from one end of the connecting portion.

[0049] The connecting part of the first bushing is fitted onto the end of the drive shaft 7 near the harmonic generator 4, and is located between the drive shaft 7 and the harmonic generator 4. The connecting part of the second bushing is fitted onto the end of the drive shaft 7 near the planet carrier 3, and is located between the drive shaft 7 and the planet carrier 3. In this way, the transmission friction between the two ends of the drive shaft 7 and the harmonic generator 4 and the planet carrier 3 can be reduced.

[0050] The support portion of the first bushing is arranged between the second gear 22 and the harmonic generator 4, and the support portion of the second bushing is arranged between the first gear 21 and the planet carrier 3. In this way, the transmission friction between the planetary gear assembly and the harmonic generator 4 and the planet carrier 3 can be reduced.

[0051] In some embodiments, there is a certain gap between the drive shaft 7 and the second bushing in the axial direction. In this way, the thermal expansion generated between the drive shaft 7 and the second bushing during transmission can be compensated, preventing damage to the drive shaft due to expansion, and also reducing wear between the drive shaft 7 and the second bushing.

[0052] Various implementations of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed implementations. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described implementations. The terminology used herein is chosen to best explain the principles, practical applications, or improvements to technology in the market, or to enable others skilled in the art to understand the various implementations disclosed herein.

Claims

1. A speed reduction device, comprising: Input gear shaft (1) is coupled to the output end of the power unit; The planetary reduction assembly includes a planetary gear assembly (2) coupled to the input gear shaft (1) and a planet carrier (3) coupled to the planetary gear assembly (2), and is adapted to transmit the rotation of the input gear shaft (1) to the planet carrier (3) after a first-stage reduction. as well as The harmonic deceleration assembly includes a harmonic generator (4) fixedly coupled to the planetary carrier (3), a flexible wheel (5) coupled to the harmonic generator (4), and a rigid wheel (6) meshing with the flexible wheel (5). The rigid wheel (6) is coupled to an external component so that the rigid wheel (6) drives the external component to rotate at the output speed after two-stage deceleration.

2. The reduction gear according to claim 1, wherein the planetary gear assembly (2) comprises: Multiple first gears (21) are arranged at equal intervals in the circumferential direction of the input gear shaft (1) to mesh with the input gear shaft (1); as well as A plurality of second gears (22) are coaxially arranged on one side of the plurality of first gears (21) in the axial direction and rotate together with the plurality of first gears (21). The outer diameter of each of the plurality of second gears (22) is smaller than the outer diameter of the corresponding first gear (21), and the module is different from the module of the corresponding first gear (21). The planetary deceleration assembly further includes: An internal gear ring (23) is arranged on the outer side of the planet carrier (3) in the radial direction and meshes with the plurality of second gears (22).

3. The speed reduction device according to claim 2, wherein the internal gear ring (23) comprises: The internal gear ring body (231) has a hollow cylindrical structure; The internal gear ring flange (232) extends radially outward from one end of the internal gear ring body (231) away from the planet carrier (3) in the axial direction; The flange portion (233) extends radially inward from one end of the internal gear ring body portion (231) near the planet carrier (3) in the axial direction; as well as A coupling portion (234) is formed radially inside the flange portion (233) and protrudes axially from the flange portion (233) to couple to the side of the harmonic deceleration assembly close to the planetary deceleration assembly in the axial direction, and the inner circumferential surface of the coupling portion (234) has internal teeth that mesh with the plurality of second gears (22).

4. The deceleration device according to claim 2, wherein the planetary deceleration assembly further comprises: Multiple drive shafts (7), each of the multiple drive shafts (7) passes through the corresponding second gear (22) and first gear (21) in the axial direction, and each drive shaft (7) is coupled to the harmonic generator (4) at one end in the axial direction and to the planet carrier (3) at the other end.

5. The deceleration device according to any one of claims 1-4, wherein the planetary carrier (3) includes a first hollow region and a plurality of first coupling structures arranged around the first hollow region.

6. The deceleration device according to claim 5, wherein the harmonic generator (4) comprises an elliptical body, the elliptical body comprising a first hollow region and a plurality of second coupling structures uniformly arranged around the first hollow region, the plurality of second coupling structures being arranged to align with the plurality of first coupling structures of the planetary carrier (3) to couple the harmonic generator (4) to the planetary carrier (3).

7. The deceleration device according to any one of claims 1-4 and 6, wherein the harmonic deceleration assembly further comprises: A thin-walled bearing (8) is coupled radially between the harmonic generator (4) and the flexible wheel (5).

8. The speed reduction device according to claim 3, wherein the flexure (5) comprises: The flexible gear ring body is coupled to the thin-walled bearing (8); The flexible gear flange extends radially outward from one end of the flexible gear ring body in the axial direction and is arranged on the side of the internal gear ring flange that is close to the harmonic generator (4) in the axial direction. as well as The first external tooth is formed on the outer circumferential surface of the flexible gear ring body in the radial direction.

9. The speed reduction device according to claim 8, wherein the rigid wheel (6) comprises: The first internal tooth meshes with the first external tooth, and the number of teeth in the first internal tooth is greater than the number of teeth in the first external tooth.

10. The speed reduction device according to any one of claims 1-4, 6, 8 and 9, further comprising: A crossed roller bearing (9) is coupled in the radial direction between the rigid wheel (6) and the flexible wheel (5) between the flexible wheel flanges to allow the rigid wheel (6) to rotate relative to the flexible wheel (5).

11. The speed reduction device according to any one of claims 1-4, 6, 8 and 9, further comprising: The first transmission bearing is coupled radially between the input gear shaft (1) and the planetary carrier (3); as well as The second transmission bearing is coupled radially between the input gear shaft (1) and the harmonic generator (4).

12. The speed reduction device according to any one of claims 1-4, 6, 8 and 9, further comprising: The first bushing and the second bushing are respectively arranged at both ends of the drive shaft (7) in the axial direction.

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