Planetary reducer, joint module and robot
By combining a progressively decreasing reduction ratio design with limiting components and crossed roller bearings, the problems of insufficient strength and increased size caused by the increase in reduction ratio in planetary reducers are solved, thus realizing a planetary reducer with high output torque and miniaturization.
Patent Information
- Application Number
- CN202511347794.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2025-11-14
AI Technical Summary
In the prior art, the first stage planetary gear reduction mechanism of the planetary reducer has a small output torque, which requires an increase in the reduction ratio, resulting in insufficient strength of the remaining stages of the planetary gear reduction mechanism and an increase in the overall size.
The design adopts a progressively decreasing reduction ratio. The reduction ratio of the first-stage planetary gear reduction mechanism is greater than or equal to 6, while the reduction ratios of other stages are less than 6. By sharing the same gear ring among multiple-stage planetary gear reduction mechanisms, redundant gear ring structures are reduced. Combined with the design of limiting components and crossed roller bearings, the tooth width of the gear pair is not increased to compensate for material strength.
It achieves high output torque and miniaturized design of planetary reducers, avoids the problem of insufficient material strength, and reduces the axial and radial dimensions of planetary reducers.
Smart Images
Figure CN120946754A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of robotics, and in particular to planetary reducers, joint modules, and robots. Background Technology
[0002] In the design of robot joint modules, the planetary reducer, as a core transmission component, has a significant impact on the overall compactness of the joint module due to its axial dimension.
[0003] However, in related technologies, because the output torque of the first-stage planetary gear reducer is relatively small, it is necessary to increase the reduction ratio of each stage of the planetary gear reducer to improve the overall reduction ratio of the planetary reducer and thus increase its overall output torque. However, increasing the reduction ratio of the remaining stages of the planetary gear reducer may lead to insufficient strength in the sun gear and planet gears. In this case, it is usually necessary to compensate for the strength by increasing the tooth width, which results in an increase in the size of the remaining stages of the planetary gear reducer, thus increasing the overall size of the planetary reducer. Summary of the Invention
[0004] This section provides a general overview of this disclosure, rather than a full disclosure of the entire scope or all features of this disclosure.
[0005] The purpose of this disclosure is to provide a planetary reducer with high output torque and miniaturization, a joint module, and a robot.
[0006] To achieve the above objectives, according to one aspect of this disclosure, a planetary reducer is provided, comprising: case; The gear ring is fixedly installed inside the housing; The planetary gear reduction mechanism assembly includes a multi-stage planetary gear reduction mechanism, each stage of which includes a sun gear and multiple planet gears, and the planet gears mesh with the ring gear. Among them, from the first-stage planetary gear reduction mechanism to the last-stage planetary gear reduction mechanism, the reduction ratio of each stage of the planetary gear reduction mechanism decreases step by step.
[0007] Optionally, in some embodiments, the reduction ratio of the first-stage planetary gear reducer is greater than or equal to 6, and the reduction ratios of all other stages of the planetary gear reducer are less than 6.
[0008] Optionally, in some embodiments, the reduction ratio of the first-stage planetary gear reducer is greater than or equal to 6 and less than or equal to 10, and the reduction ratios of the other stages of the planetary gear reducer are greater than or equal to 2 and less than 6.
[0009] Optionally, in some embodiments, the number of planetary gears in the first-stage planetary gear reduction mechanism is 3, and the number of planetary gears in the other stages of the planetary gear reduction mechanism is greater than or equal to 4.
[0010] Optionally, in some embodiments, along the axial direction of the planetary reducer, a plurality of first grooves are formed on the inner peripheral wall of the housing, and a plurality of second grooves are formed on the outer peripheral wall of the gear ring, with the first grooves and the second grooves corresponding one to one; In the radial direction of the planetary reducer, the first groove and the corresponding second groove define a first limiting hole. The first limiting member is inserted into the first limiting hole and forms an interference fit with the inner peripheral wall of the first limiting hole.
[0011] Optionally, in some embodiments, along the axial direction of the planetary reducer, a plurality of third grooves are provided on the planet carrier of the preceding stage planetary gear reducer, and a plurality of fourth grooves are provided on the sun gear of the following stage planetary gear reducer, with the third grooves corresponding to the fourth grooves one by one. In the radial direction of the planetary reducer, the third groove and the corresponding fourth groove define a second limiting hole. The second limiting member is inserted into the second limiting hole and forms an interference fit with the inner peripheral wall of the second limiting hole.
[0012] Optionally, in some embodiments, the planetary reducer further includes a crossed roller bearing, which is disposed radially between the housing and the planet carrier of the final stage planetary gear reduction mechanism. The first end of the inner peripheral wall of the housing is provided with a first flange extending radially inward, which abuts against the first surface of the crossed roller bearing; the second end of the outer peripheral wall of the planetary carrier of the final stage planetary gear reduction mechanism is provided with a second flange extending radially outward, which abuts against the second surface of the crossed roller bearing.
[0013] Alternatively, in some embodiments, the third end of the gear ring abuts against the second surface.
[0014] According to another aspect of this disclosure, a joint module is provided, which includes the planetary reducer in any of the foregoing embodiments.
[0015] According to another aspect of this disclosure, a robot is provided, which includes the joint module in any of the foregoing embodiments.
[0016] According to the above technical solution, while increasing the output torque of the planetary reducer, the other stages of the planetary gear reduction mechanism do not need to compensate for the material strength by increasing the tooth width of the gear pair, thus realizing the miniaturization design of the planetary reducer. Attached Figure Description
[0017] The features and advantages of embodiments of the present disclosure will become more readily understood from the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show detail of specific parts.
[0018] Figure 1 This is a schematic diagram of a planetary reducer provided for an embodiment of the present disclosure.
[0019] Figure 2 for Figure 1 An exploded view of the planetary decelerator is provided.
[0020] Figure 3 for Figure 1 A schematic diagram of the planetary gear reduction mechanism assembly in the provided planetary reducer.
[0021] Figure 4 for Figure 1 A cross-sectional view of the planetary reducer is provided.
[0022] Figure 5 for Figure 1 A schematic diagram of the gear ring in the provided planetary reducer.
[0023] Figure 6 for Figure 1 The provided diagram shows the assembly of the housing and gear ring in the planetary reducer.
[0024] Figure 7 for Figure 1 A schematic diagram of the first planetary carrier of the first-stage planetary gear reduction mechanism in the provided planetary reducer.
[0025] Figure 8 for Figure 1 A schematic diagram of the second sun gear planet carrier in the second-stage planetary gear reduction mechanism of the provided planetary reducer.
[0026] Figure 9 for Figure 7 The first planetary support provided and Figure 8 The provided assembly diagram of the second sun gear.
[0027] In the diagram: 10: Housing; 101: First groove; 102: First end; 1021: First flange; 20: Gear ring; 201: Second groove; 202: Third end; 30: Planetary gear reduction mechanism assembly; 301: Planetary gear reduction mechanism; 3011: Sun gear; 30111: Fourth groove; 3012: Planetary gear; 3013: Planet carrier; 30131: Third groove; 30132: Second end; 301321: Second flange; 40: First limiting hole; 50: First limiting member; 60: Second limiting hole; 70: Second limiting member; 80: Crossed roller bearing; 801: First surface; 802: Second surface. Detailed Implementation
[0028] The present disclosure will now be described in detail with reference to the accompanying drawings and exemplary embodiments. It should be noted that the following detailed description of the present disclosure is for illustrative purposes only and is not intended to limit the scope of the disclosure.
[0029] It should be noted that, for clarity, not all features of a particular embodiment are described or shown in the specification and drawings. Furthermore, to avoid unnecessary details obscuring the technical solutions of interest in this disclosure, only the device structures and parts closely related to the technical solutions of this disclosure are described and shown in the specification and drawings, while other details that are not closely related to the technical content of this disclosure and are known to those skilled in the art are omitted.
[0030] Furthermore, in the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0031] Before elaborating on the technical solution of this disclosure, it should be noted that this disclosure only uses a planetary reducer including a two-stage planetary gear reduction mechanism as an example to illustrate the technical solution. However, the planetary reducer provided in this disclosure is not limited to including only a two-stage planetary gear reduction mechanism.
[0032] Please refer to Figures 1 to 4This disclosure illustrates a planetary gear reducer 1, which includes a housing 10, a ring gear 20, and a planetary gear reduction mechanism assembly 30. Typically, the ring gear 20 is fixedly disposed within the housing 10. The planetary gear reduction mechanism assembly 30 includes a multi-stage planetary gear reduction mechanism 301, each stage of which includes a sun gear 3011, multiple planet gears 3012, and a planet carrier 3013. Furthermore, each planet gear 3012 in each stage of the planetary gear reduction mechanism 301 meshes with the ring gear 20.
[0033] Taking the planetary gear reduction mechanism assembly 30, which includes two-stage planetary gear reduction mechanisms 301, as an example, the two-stage planetary gear reduction mechanisms 301 are a first-stage planetary gear reduction mechanism 301A and a second-stage planetary gear reduction mechanism 301B. The first-stage planetary gear reduction mechanism 301A includes a first sun gear 3011A, multiple first planet gears 3012A, and a first planet carrier 3013A. The second-stage planetary gear reduction mechanism 301B includes a second sun gear 3011B, multiple second planet gears 3012B, and a second planet carrier 3013B. Furthermore, both the first planet gears 3012A and the second planet gears 3012B mesh with the gear ring 20.
[0034] It should be noted that the first sun gear 3011A in the first-stage planetary gear reduction mechanism 301A is usually connected to the output shaft of the motor in the joint module (not shown in the figure).
[0035] In this disclosure, the multi-stage planetary gear reduction mechanism 301 in the planetary reducer 1 shares the same gear ring 20. This design can reduce the number of gear rings 20 in the planetary reducer 1, eliminate redundant gear ring structures, and significantly reduce the axial dimension of the planetary reducer 1.
[0036] It should be noted that "axial dimension of planetary reducer 1" refers to the assembly length along the axial direction of planetary reducer 1.
[0037] Furthermore, the output torque of planetary reducer 1 can be expressed using the following formula (1): (1) Among them, T out T represents the output torque of planetary reducer 1. in Indicates the input torque of planetary reducer 1; i t The total reduction ratio of planetary reducer 1 can be expressed by the following formula (2): (2) Among them, i k This indicates the reduction ratio of the k-th stage planetary gear reduction mechanism 301 in planetary reducer 1; n indicates the total number of planetary gear reduction mechanisms in planetary reducer 1.
[0038] Based on equations (1) and (2) above, it can be seen that in planetary reducer 1, when at least two stages of planetary gear reduction mechanism 301 are integrated, the total reduction ratio of planetary reducer 1 can be significantly improved through the geometric cumulative effect of reduction ratio, thereby increasing the output torque of planetary reducer 1.
[0039] Furthermore, from the first-stage planetary gear reduction mechanism to the last-stage planetary gear reduction mechanism, the reduction ratio of each stage of the planetary gear reduction mechanism 301 decreases progressively.
[0040] The first-stage planetary gear reducer has the highest reduction ratio, converting high input speed and low input torque into low output speed and high output torque. When the output torque of the first-stage planetary gear reducer is high, the material strength requirements for its gear pairs (sun gear and planet gears) are usually high. In other words, when the material strength of the gear pairs in the first-stage planetary gear reducer is high, using a high reduction ratio design can eliminate the problem of redundant material strength in the gear pairs of the first-stage planetary gear reducer, thereby avoiding material waste.
[0041] It should be understood that the output torque of each stage of the planetary gear reduction mechanism is the product of its input torque and the corresponding reduction ratio. The reduction ratio of each stage of the planetary gear reduction mechanism 301 decreases progressively, which is equivalent to a gradual decrease in the amplification factor of the input torque of each stage of the planetary gear reduction mechanism 301. Although the second-stage planetary gear reduction mechanism has a high input torque, the subsequent stages of the planetary gear reduction mechanism provide a smaller amplification factor for their respective input torques. Moreover, the increased number of planetary gears in the subsequent stages of the planetary gear reduction mechanism increases the corresponding load-bearing capacity. Therefore, the subsequent stages of the planetary gear reduction mechanism avoid the problem of insufficient material strength of the gear pairs caused by bearing large input torques. Thus, it is not necessary to compensate for the material strength by increasing the tooth width of the gear pairs, and consequently, the axial dimension of the planetary reducer 1 will not expand. This is beneficial for designing a small-volume planetary reducer 1 and realizing the miniaturization design of the planetary reducer 1.
[0042] According to the above technical solution, while increasing the output torque of planetary reducer 1, the other planetary gear reduction mechanisms do not need to compensate for material strength by increasing the tooth width of the gear pair, thus realizing the miniaturization design of planetary reducer 1.
[0043] In some embodiments of this disclosure, the reduction ratio of the first-stage planetary gear reducer is greater than or equal to 6, and the reduction ratios of all other stages of the planetary gear reducer are less than 6.
[0044] In the first-stage planetary gear reducer, the reduction ratio of 6 or higher amplifies the input torque by at least 6 times, significantly increasing the output torque. Therefore, subsequent stages of the planetary gear reducer can achieve the target output torque with higher efficiency using only smaller reduction ratios, while maximizing material strength utilization. In some examples, the reduction ratio of the first-stage planetary gear reducer is greater than or equal to 6 and less than or equal to 10, while the reduction ratios of the remaining stages are greater than or equal to 2 and less than 6.
[0045] In some embodiments of this disclosure, the first-stage planetary gear reduction mechanism has 3 planetary gears, and the other stages of the planetary gear reduction mechanism have 4 or more planetary gears.
[0046] In the first-stage planetary gear reduction mechanism, the symmetrical arrangement of three planetary gears can distribute high output torque to three load points while reducing the load on the corresponding planet carrier, thereby reducing the risk of deformation of the gear ring 20. With the same tooth width, the more planetary gears there are, the stronger the load-bearing capacity of the corresponding planetary gear reduction mechanism. Therefore, when the reduction ratio of the remaining stages of the planetary gear reduction mechanism is small, the number of planetary gears in the remaining stages is set to be greater than or equal to four.
[0047] In some embodiments of this disclosure, reference continues to be made to Figure 2 Along the axial direction of the planetary reducer 1, a plurality of first grooves 101 are formed on the inner peripheral wall of the housing 10, as shown in the figure. Figure 5 The outer peripheral wall of the gear ring 20 is provided with a plurality of second grooves 201, and the first groove 101 corresponds one-to-one with the second groove 201; Please refer to Figure 6 In the radial direction of the planetary reducer 1, the first groove 101 and the corresponding second groove 201 define a first limiting hole 40. Combined with... Figure 2 The first limiting member 50 is inserted into the first limiting hole 40 and forms an interference fit with the inner peripheral wall of the first limiting hole 40.
[0048] In this configuration, the interference preload provides radial support to the gear ring 20. This eliminates the assembly clearance between the gear ring 20 and the housing 10, and restricts the radial movement of the gear ring 20 along the planetary reducer 1 and its rotation relative to the housing 10. Thus, while ensuring the coaxiality of the gear ring 20 and the housing 10, it also prevents an increase in the thickness of the gear ring 20 due to assembly issues, thereby helping to reduce the radial dimension of the planetary reducer 1.
[0049] It should be understood that "radial dimension of planetary reducer 1" refers to the assembly length along the radial direction of planetary reducer 1.
[0050] In some embodiments of this disclosure, please refer to Figure 7 Along the axial direction of the planetary reducer, multiple third grooves 30131 are provided on the planet carrier 3013 of the previous stage planetary gear reduction mechanism, as shown in the reference. Figure 8 The sun gear 3011 of the next stage planetary gear reduction mechanism has multiple fourth grooves 30111, and the third groove 30131 corresponds to the fourth groove 30111 one by one. Among them, reference Figure 9 In the radial direction of the planetary reducer 1, the third groove 30131 and the corresponding fourth groove 30111 define a second limiting hole 60. (Combined with...) Figure 3 The second limiting member 70 is inserted into the second limiting hole 60 and forms an interference fit with the inner peripheral wall of the second limiting hole 60.
[0051] Taking the planetary gear reduction mechanism assembly 30, which includes two-stage planetary gear reduction mechanisms 301, as an example, multiple third grooves 30131 are formed on the first planet carrier 3013A of the first-stage planetary gear reduction mechanism 301-1, and multiple fourth grooves 30111 are formed on the second sun gear 3011B of the second-stage planetary gear reduction mechanism 301-2. A second limiting member 70 is inserted into a second limiting hole 60 formed by the third grooves 30131 and the corresponding fourth grooves 30111, and forms an interference fit with the inner peripheral wall of the second limiting hole 60. In this case, relative rotation between the first planet carrier 3013A of the first-stage planetary gear reduction mechanism 301-1 and the second sun gear 3011B of the second-stage planetary gear reduction mechanism 301-2 can be restricted. Thus, compared to the spline connection method in related technologies, the connection method provided in this disclosure, while ensuring coaxiality, is simpler to manufacture and has lower manufacturing costs.
[0052] In some embodiments of this disclosure, reference continues to be made to Figure 2 The planetary reducer 1 also includes a crossed roller bearing 80, which is disposed between the housing 10 and the planet carrier 3013 of the final stage planetary gear reduction mechanism along the radial direction of the planetary reducer 1. The first end 102 of the inner peripheral wall of the housing 10 is provided with a first flange 1021 extending radially inward, which abuts against the first surface 801 of the crossed roller bearing 80; the second end 30132 of the outer peripheral wall of the planet carrier 3013 of the final stage planetary gear reduction mechanism is provided with a second flange 301321 extending radially outward, which abuts against the second surface 802 of the crossed roller bearing 80.
[0053] In this configuration, the first flange 1021 abuts against the first surface 801 of the crossed roller bearing 80, and the second flange 301321 abuts against the second surface 802 of the crossed roller bearing 80. This prevents the crossed roller bearing 80 from moving radially along the planetary reducer 1. Furthermore, it avoids the need for additional fittings to secure the crossed roller bearing 80, thus helping to reduce the radial dimension of the planetary reducer 1.
[0054] In the axial direction of the planetary reducer 1, in order to avoid increasing the size, in some embodiments, the third end 202 of the gear ring 20 abuts against the second surface 802.
[0055] In the axial direction of the planetary reducer 1, the cross roller bearing 80 is supported by the gear ring 20, which reduces the installation size of the cross roller bearing 80 in this axial direction and helps to reduce the axial dimension of the planetary reducer 1.
[0056] In addition, this disclosure also provides a joint module, which includes the planetary reducer 1 in any of the foregoing technical solutions.
[0057] Finally, this disclosure also provides a robot that includes the joint module in any of the foregoing technical solutions.
[0058] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the specific embodiments described and shown herein. Various changes to the exemplary embodiments can be made by those skilled in the art without departing from the scope defined by the claims of this disclosure.
[0059] The features mentioned and / or shown in the foregoing description of exemplary embodiments of this disclosure may be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. Such combinations or substitutions should also be considered as including within the scope of protection of this disclosure.
Claims
1. A planetary reducer, characterized in that, The planetary reducer includes: Shell (10); A gear ring (20) is fixedly disposed inside the housing (10); The planetary gear reduction mechanism assembly (30) includes a multi-stage planetary gear reduction mechanism (301), each stage of the planetary gear reduction mechanism (301) includes a sun gear (3011) and a plurality of planet gears (3012), and the planet gears (3012) mesh with the gear ring (20); Among them, from the first stage planetary gear reduction mechanism to the last stage planetary gear reduction mechanism, the reduction ratio of each stage planetary gear reduction mechanism decreases progressively.
2. The planetary reducer according to claim 1, characterized in that, The reduction ratio of the first-stage planetary gear reduction mechanism is greater than or equal to 6, and the reduction ratio of the planetary gear reduction mechanisms in all other stages is less than 6.
3. The planetary reducer according to claim 2, characterized in that, The reduction ratio of the first-stage planetary gear reduction mechanism is greater than or equal to 6 and less than or equal to 10, and the reduction ratio of the other stages of the planetary gear reduction mechanism is greater than or equal to 2 and less than 6.
4. The planetary reducer according to claim 2 or 3, characterized in that, The first-stage planetary gear reduction mechanism has 3 planetary gears, and the other stages of the planetary gear reduction mechanism have 4 or more planetary gears.
5. The planetary reducer according to any one of claims 1 to 3, characterized in that, Along the axial direction of the planetary reducer, a plurality of first grooves (101) are provided on the inner peripheral wall of the housing (10), and a plurality of second grooves (201) are provided on the outer peripheral wall of the gear ring (20), with the first grooves (101) and the second grooves (201) corresponding one to one; In the radial direction of the planetary reducer, the first groove (101) and the corresponding second groove (201) define a first limiting hole (40), and the first limiting member (50) is inserted into the first limiting hole (40) and forms an interference fit with the inner peripheral wall of the first limiting hole (40).
6. The planetary reducer according to any one of claims 1 to 3, characterized in that, Along the axial direction of the planetary reducer, the planet carrier of the previous stage planetary gear reduction mechanism is provided with a plurality of third grooves (30131), and the sun gear of the next stage planetary gear reduction mechanism is provided with a plurality of fourth grooves (30111). The third grooves (30131) and the fourth grooves (30111) correspond one-to-one. In the radial direction of the planetary reducer, the third groove (30131) and the corresponding fourth groove (30111) define a second limiting hole (60), and the second limiting member (70) is inserted into the second limiting hole (60) and forms an interference fit with the inner peripheral wall of the second limiting hole (60).
7. The planetary reducer according to any one of claims 1 to 3, characterized in that, It also includes a crossed roller bearing (80) arranged radially along the planetary reducer between the housing (10) and the planet carrier of the final stage planetary gear reduction mechanism; The first end (102) of the inner peripheral wall of the housing (10) is provided with a first flange (1021) extending inward along the radial direction, and the first flange (1021) abuts against the first surface (801) of the crossed roller bearing (80); the second end (30132) of the outer peripheral wall of the planetary carrier of the final stage planetary gear reduction mechanism is provided with a second flange (301321) extending outward along the radial direction, and the second flange (301321) abuts against the second surface (802) of the crossed roller bearing (80).
8. The planetary reducer according to claim 7, characterized in that, The third end (202) of the gear ring (20) abuts against the second surface (802).
9. A joint module, characterized in that, The joint module includes the planetary reducer as described in any one of claims 1 to 8.
10. A robot, characterized in that, The robot includes the joint module according to claim 9.