Speed reducer for humanoid robot and manufacturing method thereof

Abstract

The embodiment of the invention provides a speed reducer for a humanoid robot and a manufacturing method thereof, and relates to the technical field of speed reducers. The speed reducer for the humanoid robot comprises a crossed roller bearing, a steel wheel, a flexible wheel, a flexible bearing, a wave generator cam, a coupler and a positioning pin, the crossed roller bearing is fixedly connected with the steel wheel through an interior angle bolt, a framework oil seal assembly is installed on the crossed roller bearing to provide sealing, and the flexible wheel is arranged in the steel wheel in a sleeved mode. A flexible bearing is installed in the flexible gear, a wave generator cam is arranged in the flexible bearing, and a coupler is installed on one side of the wave generator cam. Through the optimized connection design of the crossed roller bearing and the steel wheel and precise matching of the positioning pin, the copper gasket, the waveform gasket and the clamping spring, the rotating precision, the bearing capacity and the rigidity are remarkably improved, meanwhile, the structural stability and the modular assembly performance are enhanced, and the universal joint is particularly suitable for a humanoid robot joint driving system under the complex working condition.

Description

Technical Field

[0001] The present application relates to the technical field of reducer technology, and in particular, to a reducer for a humanoid robot and a method for manufacturing the same. Background Art

[0002] In the field of humanoid robots, reducers, as core transmission components, are widely used in joint drive systems. Their performance directly affects the overall motion accuracy, response speed, and service life of the entire robot. Currently, commonly used harmonic reducers typically include key components such as a flexspline, a steel wheel, a flexible bearing, and a wave generator. They offer significant advantages in high-precision transmission. However, traditional structures still have many shortcomings in practical applications.

[0003] First, regarding the transmission structure, existing reducers mostly use conventional bearing supports, which have limited rotational accuracy and load-bearing capacity, making them difficult to meet the complex operating conditions of humanoid robots, such as frequent starts and stops and high load fluctuations in joints. Furthermore, the connection between the wave generator and the coupling is relatively simple and lacks an effective preload adjustment mechanism, resulting in an inability to compensate for assembly clearance, affecting transmission rigidity and backlash control accuracy, and thus reducing the positioning accuracy of the entire machine.

[0004] Secondly, in terms of seal structure design, traditional skeleton oil seals often use a single lip structure, and the lip lacks sufficient mechanical support. This lip is prone to deformation such as curling and shrinking during long-term operation, causing seal failure, affecting the lubrication environment within the reducer, and even causing system failure. Furthermore, the oil seal's overall structural strength is low, and its ability to resist side loads and protection level are insufficient, making it difficult to adapt to the highly dynamic and high-cleanliness working environment of humanoid robots. Summary of the Invention

[0005] To achieve the above-mentioned objectives, on the one hand, the present invention provides a reducer for a humanoid robot, comprising a crossed roller bearing, a steel wheel, a flexible wheel, a flexible bearing, a wave generator cam, a coupling and a locating pin, wherein the crossed roller bearing is fixedly connected to the steel wheel by an internal angle bolt, and the skeleton oil seal assembly is installed on the crossed roller bearing to provide sealing, a flexible wheel is sleeved inside the steel wheel, a flexible bearing is installed inside the flexible wheel, a wave generator cam is provided inside the flexible bearing, a coupling is installed on one side of the wave generator cam, the wave generator cam and the interior of the coupling are fixedly connected by a locating pin, the locating pin passes through the flange, and the flange is fixed to the crossed roller bearing by an internal angle bolt.

[0006] Furthermore, a copper gasket and a corrugated gasket are sequentially sleeved on the outer side of the locating pin, wherein the copper gasket is located on the side close to the wave generator cam, and the corrugated gasket is attached to the surface of the wave generator cam for adjusting the preload force. A slot is opened at a specific position of the locating pin, and a retaining spring is embedded in the slot to limit the position of the copper gasket and prevent it from moving axially along the locating pin.

[0007] Furthermore, the skeleton oil seal assembly includes an inner skeleton, an outer sealing layer is provided on the outer side of the inner skeleton, and an inner lip and an outer lip are respectively provided on both sides of the outer sealing layer.

[0008] Furthermore, an elastic support is installed between the outer lip and the inner lip, and a plurality of elastic supports are provided and annularly distributed in the installation groove provided in the outer sealing layer.

[0009] Furthermore, a plurality of support rings are distributed in an annular manner on both sides of the inner skeleton, and one end of the support rings on both sides is connected to the edge of the inner lip and the outer lip respectively.

[0010] Furthermore, the outer sealing layer is made of high-temperature resistant fluororubber material, and the inner skeleton is made of stainless steel material.

[0011] Furthermore, in another aspect, the present invention also provides a method for manufacturing a reducer, including the reducer for a humanoid robot described in any one of the above, comprising the following steps:

[0012] S1. The inner and outer rings of the crossed roller bearings are processed through precision turning and heat treatment processes. Precision-ground rollers are evenly arranged between the inner and outer rings. The crossed roller bearings are fixed to the steel wheel with internal angle bolts, and the skeleton oil seal assembly is installed on the crossed roller bearings.

[0013] S2, Flexspline uses high-precision CNC machine tools to cut and shape the metal material, and heat treats it to improve its hardness and wear resistance, and then sets it inside the steel wheel;

[0014] S3. Install a flexible bearing inside the flexible wheel and ensure interference fit through cold press fitting. A wave generator cam is set inside the flexible bearing to form a harmonic transmission pair.

[0015] S4. Install a coupling on one side of the wave generator cam, and circumferentially position and securely connect the wave generator cam and the coupling using positioning pins;

[0016] S5. Install the copper gasket and corrugated gasket on the locating pin in sequence, and insert the retaining spring into the groove on the locating pin to limit the axial displacement of the copper gasket. Fix the flange to the cross roller bearing with the internal angle bolts to complete the overall assembly of the reducer.

[0017] Furthermore, the assembly steps of the skeleton oil seal assembly include:

[0018] The inner frame is made of high-strength stainless steel material through stamping and machining;

[0019] An outer sealing layer formed of high-temperature resistant fluororubber material is coated on the outside of the inner frame through a vulcanization process;

[0020] An inner lip and an outer lip are formed on both sides of the outer sealing layer by a mold to form a double sealing structure;

[0021] A plurality of elastic supports are arranged in an annular manner between the outer lip and the inner lip, and the elastic supports are then installed in the installation grooves provided in the outer sealing layer.

[0022] Furthermore, in the further assembly process of the skeleton oil seal assembly, the following steps are further included:

[0023] Multiple support rings are distributed in an annular manner on both sides of the inner frame by welding;

[0024] One end of the support ring is integrally connected to the edges of the inner lip and the outer lip through a vulcanization process.

[0025] Furthermore, the corrugated gasket is made of a high-elasticity alloy steel material and is formed into a wavy elastic structure through a stamping process.

[0026] 1. The beneficial effects of this application are as follows: The structural design of a fixed connection between a crossed roller bearing and a steel wheel improves the rotational accuracy and load-bearing capacity of the overall transmission system. The wave generator cam and coupling are circumferentially positioned using locating pins. Combined with copper washers, corrugated washers, and a retaining spring structure, effective compensation for assembly clearance and precise adjustment of preload are achieved, thereby enhancing the rigidity and backlash control capabilities of the harmonic drive system. Furthermore, the flange is fixed to the crossed roller bearing via internal angle bolts, further enhancing the structural stability and modular assembly performance. This ensures that the reducer meets lightweight requirements while also offering higher reliability and maintainability, making it suitable for humanoid robot joint drive systems operating under complex working conditions.

[0027] 2. The beneficial effects of the present application are as follows: the skeleton oil seal assembly adopts a composite structure that combines an inner skeleton made of high-strength stainless steel with an outer sealing layer composed of high-temperature resistant fluororubber material, which significantly improves the durability and deformation resistance of the oil seal while ensuring the sealing performance. By setting a double lip structure (inner lip and outer lip) and coordinating with annularly distributed elastic supports, the fitting stability of the sealing interface is effectively enhanced to prevent the entry of external dust and leakage of internal grease. At the same time, support rings are provided on both sides of the oil seal and are integrally connected to the lip edge through a vulcanization process, which not only improves the overall mechanical strength of the oil seal assembly, but also enhances its radial load-bearing capacity under eccentric load or vibration environments, thereby extending the service life of the reducer and improving the overall protection level. It is particularly suitable for humanoid robot application scenarios with high dynamic response and high cleanliness requirements.

[0028] 3. The beneficial effects of this application are as follows: the elastic supports are installed in an annular manner within the mounting grooves defined by the outer sealing layer, providing uniform and continuous radial support for the inner and outer lips, effectively preventing curling or shrinkage of the lips that may occur during long-term use. The support rings are integrally connected to the edges of the inner and outer lips through a vulcanization process or welding, which not only increases the mechanical strength of the lips but also further enhances their ability to withstand external pressure and vibration. This dual support mechanism ensures that the lips maintain a good fit even under extreme operating conditions, avoiding seal failure due to deformation. Therefore, this design greatly extends the service life of the skeleton oil seal assembly and improves the overall reliability and maintenance cycle of the reducer.

[0029] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 is a schematic diagram of the overall structure according to an embodiment of the present application;

[0032] Figure 2 is an exploded schematic diagram of the overall structure according to an embodiment of the present application;

[0033] Figure 3 is a schematic top view of the flexible pulley and other structures according to an embodiment of the present application;

[0034] Figure 4 According to the embodiment of the present application Figure 3 AA cross-sectional view;

[0035] Figure 5 According to the embodiment of this application Figure 4 Schematic diagram of the structure at A;

[0036] Figure 6 is a schematic structural diagram of a skeleton oil seal assembly according to an embodiment of the present application;

[0037] Figure 7 This is an exploded schematic diagram of the skeleton oil seal assembly structure according to an embodiment of the present application;

[0038] Figure 8 is a schematic diagram of the structure of the outer sealing layer according to an embodiment of the present application;

[0039] Figure 9 It is a flow chart of the overall structure according to an embodiment of the present application.

[0040] icon:

[0041] 1. Crossed roller bearing; 2. Skeleton oil seal assembly; 21. Inner skeleton; 22. Outer sealing layer; 23. Inner lip; 24. Outer lip; 25. Mounting groove; 26. Elastic support; 27. Support ring; 3. Locating pin; 31. Slot; 4. Flange; 5. Coupling; 6. Wave generator cam; 7. Copper gasket; 8. Circlip; 9. Wave gasket; 10. Flexible bearing; 11. Flexspline; 12. Steel wheel. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0043] The following describes a speed reducer for a humanoid robot and a method for manufacturing the same according to embodiments of the present application with reference to the accompanying drawings.

[0044] like Figures 1-9 As shown, the reducer for a humanoid robot according to an embodiment of the present application includes a cross-roller bearing 1, a steel wheel 12, a flexible wheel 11, a flexible bearing 10, a wave generator cam 6, a coupling 5 and a locating pin 3, wherein the cross-roller bearing 1 is fixedly connected to the steel wheel 12 by an internal angle bolt. This structure not only improves the connection rigidity between the bearing and the steel wheel 12, but also enhances the rotation accuracy and load-bearing capacity of the overall transmission system, and is particularly suitable for working scenarios in which humanoid robots frequently start and stop and have high dynamic response.

[0045] The skeleton oil seal assembly 2, mounted on the cross-roller bearing 1, seals the reducer's interior, preventing grease leakage and the ingress of foreign matter, thereby increasing the reducer's service life and reliability. A flexible spline 11 is nestled within the steel wheel 12. A flexible bearing 10 is mounted within the flexible spline 11, and a wave generator cam 6 is housed within the flexible bearing 10, forming the core structure of the harmonic drive. A coupling 5 is mounted on one side of the wave generator cam 6, which is circumferentially positioned and securely connected to the coupling via a locating pin 3, ensuring stable and synchronized power transmission.

[0046] Furthermore, the flange 4 is fixed to the cross roller bearing 1 by means of internal angle bolts and is penetrated by the locating pin 3. This structure not only improves the coaxiality of the overall assembly, but also enhances the modular design feature of the reducer, facilitating disassembly, maintenance and mass production.

[0047] The outer side of the locating pin 3 is successively sleeved with a copper gasket 7 and a corrugated gasket 9, wherein the copper gasket 7 is located on the side close to the wave generator cam 6, and the corrugated gasket 9 is attached to the surface of the wave generator cam 6. The two work together to effectively absorb assembly stress, compensate for the tiny gap between components, and provide a certain elastic preload through the corrugated gasket 9, thereby improving the rigidity of the transmission system and the backlash control accuracy.

[0048] Furthermore, a retaining groove 31 is defined at a specific location on the locating pin 3, into which a retaining spring 8 is inserted. This restricts the axial movement of the copper washer 7, preventing it from shifting or falling off during operation, thereby ensuring the stability and reliability of the entire preload adjustment mechanism. This design not only improves the reducer's overall performance but also significantly enhances its adaptability to complex operating conditions, making it particularly suitable for use in service humanoid robots, where precision and longevity are paramount.

[0049] like Figures 5 to 8 As shown, the skeleton oil seal assembly 2 includes an inner skeleton 21 made of high-strength stainless steel material, and the outer side of the inner skeleton 21 is covered with an outer sealing layer 22. The outer sealing layer 22 is preferably made of high-temperature resistant fluororubber material, which has excellent heat resistance, oil resistance and aging resistance, and can maintain a good sealing effect for a long time under complex working conditions.

[0050] An inner lip 23 and an outer lip 24 are respectively provided on both sides of the outer sealing layer 22, which together constitute a double sealing structure, which can effectively prevent the leakage of grease inside the reducer and prevent external dust and impurities from entering, thereby improving the service life and operating stability of the reducer.

[0051] Furthermore, a plurality of elastic supports 26 are provided between the outer lip 24 and the inner lip 23. The elastic supports 26 are distributed in a ring shape and embedded in the mounting groove 25 opened in the outer sealing layer 22. The elastic supports 26 can provide continuous and uniform radial support force for the inner lip 23 and the outer lip 24, effectively preventing the lips from deforming such as curling and shrinking during use, thereby ensuring that the sealing interface always maintains a good fit and improving the sealing reliability.

[0052] In addition, a plurality of support rings 27 distributed along the circumferential direction are provided on both sides of the inner skeleton 21. One end of the support ring 27 is respectively connected to the edge of the inner lip 23 and the outer lip 24 to form an integrated structure. The support ring 27 not only enhances the mechanical strength of the lip part, but also improves its ability to resist external interference such as unbalanced load and vibration.

[0053] The elastic support 26 can be made of spring steel or stainless steel.

[0054] On the other hand, the present invention also provides a method for manufacturing a reducer for a humanoid robot, the operating steps of which are as follows:

[0055] S1. The inner and outer rings of the cross roller bearing 1 are processed by precision turning and heat treatment, and precision-ground rollers are evenly arranged between the inner and outer rings. The cross roller bearing 1 is fixed to the steel wheel 12 with internal angle bolts, and the skeleton oil seal assembly 2 is installed on the cross roller bearing 1;

[0056] The assembly steps of the skeleton oil seal assembly 2 include:

[0057] The inner frame 21 is made of high-strength stainless steel material by stamping and machining;

[0058] The outer side of the inner frame 21 is coated with an outer sealing layer 22 made of high temperature resistant fluororubber material through a vulcanization process;

[0059] An inner lip 23 and an outer lip 24 are formed on both sides of the outer sealing layer 22 by a mold to form a double sealing structure;

[0060] A plurality of elastic supports 26 are arranged in an annular manner between the outer lip 24 and the inner lip 23 , and the elastic supports 26 are then installed in the installation grooves 25 provided in the outer sealing layer 22 .

[0061] Furthermore, the further assembly process of the skeleton oil seal assembly 2 also includes:

[0062] Multiple support rings 27 are distributed in an annular manner on both sides of the inner frame 21 by welding;

[0063] One end of the support ring 27 is integrally connected to the edges of the inner lip 23 and the outer lip 24 through a vulcanization process.

[0064] S2, the flexible wheel 11 uses a high-precision CNC machine tool to cut and shape the metal material, and improves the hardness and wear resistance through heat treatment, and then it is sleeved inside the steel wheel 12;

[0065] S3. Install the flexible bearing 10 in the flexible wheel 11 and ensure interference fit by cold press fitting. Set the wave generator cam 6 inside the flexible bearing 10 to form a harmonic transmission pair;

[0066] S4. Install the coupling 5 on one side of the wave generator cam 6, and circumferentially position and securely connect the wave generator cam 6 and the coupling 5 through the positioning pin 3;

[0067] S5. Install the copper gasket 7 and the corrugated gasket 9 on the locating pin 3 in sequence, and insert the retaining spring 8 into the slot 31 on the locating pin 3 to limit the axial displacement of the copper gasket 7. Fix the flange 4 to the cross roller bearing 1 with the internal angle bolts to complete the overall assembly of the reducer.

[0068] The corrugated gasket 9 is made of a highly elastic alloy steel material and is formed into a corrugated elastic structure through a stamping process.

[0069] The above are merely examples of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may be subject to various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0070] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A reducer for a humanoid robot, characterized in that: The invention comprises a cross roller bearing (1), a steel wheel (12), a flexible wheel (11), a flexible bearing (10), a wave generator cam (6), a coupling (5) and a positioning pin (3). The cross roller bearing (1) is fixedly connected to the steel wheel (12) by an inner angle bolt. The skeleton oil seal assembly (2) is installed on the cross roller bearing (1) to provide sealing. The steel wheel (12) is provided with a flexible wheel (11). The flexible bearing (10) is installed in the flexible wheel (11). The wave generator cam (6) is provided in the flexible bearing (10). The coupling (5) is installed on one side of the wave generator cam (6). The wave generator cam (6) and the coupling (5) are fixedly connected by a positioning pin (3). The positioning pin (3) passes through a flange (4). The flange (4) is fixed to the cross roller bearing (1) by an inner angle bolt.

2. The reducer for a humanoid robot according to claim 1, characterized in that: The outer side of the positioning pin (3) is sequentially sleeved with a copper washer (7) and a corrugated washer (9), wherein the copper washer (7) is located on a side close to the wave generator cam (6), and the corrugated washer (9) is attached to the surface of the wave generator cam (6) and is used to adjust the preload force. A slot (31) is provided at a specific position of the positioning pin (3), and a retaining spring (8) is embedded in the slot (31) to limit the position of the copper washer (7) and prevent it from moving axially along the positioning pin (3).

3. The reducer for a humanoid robot according to claim 1, characterized in that: The skeleton oil seal assembly (2) comprises an inner skeleton (21), an outer sealing layer (22) is provided on the outer side of the inner skeleton (21), and inner lips (23) and outer lips (24) are respectively provided on both sides of the outer sealing layer (22).

4. The speed reducer for a humanoid robot according to claim 3, characterized in that: An elastic support (26) is installed between the outer lip (24) and the inner lip (23). The elastic support (26) is provided in plurality and is annularly distributed in the installation groove (25) provided in the outer sealing layer (22).

5. The speed reducer for a humanoid robot according to claim 4, characterized in that: A plurality of support rings (27) are distributed in an annular manner on both sides of the inner skeleton (21), and one end of the support rings (27) on both sides is connected to the edge of the inner lip (23) and the outer lip (24) respectively.

6. The speed reducer for a humanoid robot according to claim 5, characterized in that: The outer sealing layer (22) is made of high-temperature resistant fluororubber material, and the inner skeleton (21) is made of stainless steel material.

7. A method for manufacturing a reducer, comprising the reducer for a humanoid robot according to any one of claims 1 to 6, characterized in that: The steps include: S1, the inner ring and outer ring of the cross roller bearing (1) are processed by precision turning and heat treatment process, and the rollers that have been precisely ground are evenly arranged between the inner and outer rings. The cross roller bearing (1) is fixedly connected to the steel wheel (12) by internal angle bolts, and the skeleton oil seal assembly (2) is installed at the cross roller bearing (1); S2, the flexible wheel (11) is cut and formed by a high-precision CNC machine tool, and the hardness and wear resistance are improved by heat treatment, and then it is sleeved inside the steel wheel (12); S3, installing a flexible bearing (10) in the flexible wheel (11), and ensuring interference fit by cold press fitting, and setting a wave generator cam (6) inside the flexible bearing (10) to form a harmonic transmission pair; S4. Install the coupling (5) on one side of the wave generator cam (6), and circumferentially position and securely connect the wave generator cam (6) and the coupling (5) using the positioning pin (3); S5. The copper gasket (7) and the corrugated gasket (9) are sequentially mounted on the positioning pin (3), and the circlip (8) is embedded in the groove (31) on the positioning pin (3) to limit the axial displacement of the copper gasket (7). The flange (4) is fixed to the cross roller bearing (1) by internal angle bolts, thereby completing the overall assembly of the reducer.

8. The method for manufacturing a reducer according to claim 7, wherein: The assembly steps of the skeleton oil seal assembly (2) include: The inner frame (21) is made of high-strength stainless steel material by stamping and machining; An outer sealing layer (22) formed of a high-temperature resistant fluororubber material is coated on the outer side of the inner skeleton (21) through a vulcanization process; An inner lip (23) and an outer lip (24) are respectively formed on both sides of the outer sealing layer (22) by a mold to form a double sealing structure; A plurality of elastic supports (26) are arranged in a ring shape between the outer lip (24) and the inner lip (23), and the elastic supports (26) are then installed in the installation groove (25) opened in the outer sealing layer (22).

9. The method for manufacturing a reducer according to claim 8, wherein: The further assembly process of the skeleton oil seal assembly (2) further includes: A plurality of support rings (27) are distributed in an annular manner on both sides of the inner frame (21) by welding; One end of the support ring (27) is integrally connected to the edges of the inner lip (23) and the outer lip (24) through a vulcanization process.

10. The method for manufacturing a reducer according to claim 7, wherein: The corrugated gasket (9) is made of a high-elasticity alloy steel material and is formed into a corrugated elastic structure through a stamping process.

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