Double-steel-wheel harmonic reducer for humanoid robot and humanoid robot

Abstract

The invention relates to the technical field of harmonic reducers, and particularly discloses a double-steel-wheel harmonic reducer for a humanoid robot and the humanoid robot. The double-steel-wheel harmonic reducer comprises a steel wheel assembly, a flexible wheel assembly and a wave generator; the steel wheel assembly comprises a first steel wheel and a second steel wheel, the first steel wheel and the second steel wheel are of an annular structure, the flexible wheel assembly is arranged in annular containing cavities of the first steel wheel and the second steel wheel, a first inner tooth structure is formed on the inner side of the first steel wheel, a second inner tooth structure is formed on the inner side of the second steel wheel, and the flexible wheel assembly is of an annular structure. An outer tooth structure meshed with the first inner tooth structure and the second inner tooth structure is formed on the outer side of the flexible gear assembly, tooth number difference exists between the first inner tooth structure and / or the second inner tooth structure and the outer tooth structure, the wave generator is used in cooperation with the flexible gear assembly, and the wave generator drives the first steel wheel and / or the second steel wheel to be in meshed transmission through the flexible gear assembly. By means of the double-steel-wheel structure, miniaturization and light weight are achieved, and meanwhile the performance of the harmonic reducer is kept.

Description

Technical Field

[0001] The present invention relates to the technical field of harmonic reducers, and in particular discloses a double steel wheel harmonic reducer for humanoid robots and a humanoid robot. Background Art

[0002] Due to its advantages such as high transmission efficiency, small size, light weight, smooth transmission, and low noise, the harmonic reducer has been widely used in the field of robots, especially outstanding in collaborative robotic arms and service robots. With the continuous progress of robot technology, the performance requirements for harmonic reducers are also increasing day by day. The rapid development of industrial automation and the field of robotics has promoted the evolution of harmonic reducers towards higher performance.

[0003] Under the current technical background, the harmonic reducer industry is facing the challenges of product miniaturization and lightweighting. This trend stems from the increasing compactness of machine equipment and the need for space constraints. Miniaturization and lightweighting are not just simple size reduction and weight loss. More importantly, these goals are achieved while maintaining or improving the performance of the reducer. Such improvements help to enhance the overall efficiency and flexibility of the equipment, while reducing costs and occupied space.

[0004] In addition, with the rapid development of humanoid robot technology, higher requirements are put forward for performance indicators such as the accuracy, stiffness, and lifespan of harmonic reducers. Traditional harmonic reducers have certain limitations in meeting the complex motion requirements of humanoid robots, especially facing challenges in the balance of joint flexibility and load capacity.

[0005] When existing harmonic reducers are applied to humanoid robots, it is often difficult to simultaneously meet the requirements of high precision and high stiffness. This may lead to problems such as inaccurate positioning or excessive vibration in actual motion, affecting the overall performance and working efficiency of humanoid robots. At the same time, the structural design of traditional harmonic reducers also has deficiencies in adapting to the multi-degree-of-freedom motion of humanoid robots and is difficult to meet the needs of complex movements. Summary of the Invention

[0006] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide a double steel wheel harmonic reducer for humanoid robots with miniaturization and lightweighting.

[0007] To achieve the above object, a double steel wheel harmonic reducer for a humanoid robot according to the present invention includes a steel wheel assembly, a flexspline assembly and a wave generator; the steel wheel assembly includes a first steel wheel and a second steel wheel, the first steel wheel and the second steel wheel are of an annular structure, the flexspline assembly is placed in the annular accommodating cavity of the first steel wheel and the second steel wheel, a first internal tooth structure is formed on the inner side of the first steel wheel, a second internal tooth structure is formed on the inner side of the second steel wheel, the flexspline assembly is of an annular structure, an external tooth structure meshing with the first internal tooth structure and the second internal tooth structure is formed on the outer side of the flexspline assembly, there is a tooth number difference between the first internal tooth structure and / or the second internal tooth structure and the external tooth structure, the wave generator is used in cooperation with the flexspline assembly, and the wave generator drives the first steel wheel and / or the second steel wheel to engage and transmit through the flexspline assembly. By adopting the double steel wheel structure and the flexspline assembly, the miniaturization and light weight of the harmonic reducer are realized, and at the same time, high transmission efficiency and transmission stability are ensured. The wave generator drives the steel wheel to engage and transmit through the flexspline assembly, effectively solving the noise problem of the reducer. The overall design enables the reducer to achieve higher torque output in a smaller volume, meeting the strict requirements for the performance of the reducer in the robot field.

[0008] Further, the internal tooth structure is a needle roller, and there are multiple groups of needle rollers. The multiple groups of needle rollers are arranged circumferentially on the inner sides of the first steel wheel and the second steel wheel. Accommodating grooves for accommodating the needle rollers are provided on the inner sides of the first steel wheel and the second steel wheel, and the needle rollers are rotatably arranged on the first steel wheel and the second steel wheel through the accommodating grooves. By circumferentially arranging multiple groups of needle rollers on the inner sides of the first steel wheel and the second steel wheel, the flexspline assembly and the steel wheel assembly are meshed and transmitted through the needle rollers, converting the sliding friction of the tooth meshing between the original flexible gear and the rigid gear into rolling friction, effectively reducing wear, thereby increasing the service life of the reducer. After long-term use, high-precision speed reduction transmission can also be maintained; the needle rollers can rotate freely in the accommodating grooves but cannot be separated from the accommodating grooves, and a limiting structure can be installed on the reducer to limit the separation of the needle rollers from the accommodating grooves.

[0009] Further, the needle rollers of the first steel wheel are inclined, and the included angle between the length direction of the needle rollers of the first steel wheel and the length direction of the first steel wheel is 0.1°-6°. During the rotation of the flexspline assembly, elastic deformation will occur. The free ends on both sides of the flexspline assembly will warp due to the deformation, causing the first internal tooth structure to disengage from the external tooth structure. By inclining the needle rollers, the meshing efficiency between the external tooth structure of the flexspline assembly and the first external tooth structure of the first steel wheel is improved, thereby extending the service life of the harmonic reducer.

[0010] Furthermore, the needle rollers of the second steel wheel are inclined, and the included angle between the length direction of the needle rollers of the second steel wheel and the length direction of the second steel wheel is 174° - 179.9°. During the rotation of the flexspline assembly, elastic deformation will occur. The free ends on both sides of the flexspline assembly will warp due to the deformation, causing the first internal tooth structure to disengage from the external tooth structure. By setting the needle rollers inclined, the meshing efficiency between the external tooth structure of the flexspline assembly and the second external tooth structure of the second steel wheel is improved, thereby extending the service life of the harmonic reducer.

[0011] Furthermore, the number of teeth of the internal tooth structure of the first steel wheel is the same as that of the external tooth structure, and the difference in the number of teeth between the internal tooth structure and the external tooth structure of the second steel wheel is 2. The fact that the number of teeth of the internal tooth structure of the first steel wheel is the same as that of the external tooth structure means that there will be no difference in the number of teeth during the meshing process between the first steel wheel and the flexspline assembly, thus ensuring the stability of the transmission. The difference in the number of teeth between the internal tooth structure and the external tooth structure of the second steel wheel is 2. This specific design of the difference in the number of teeth enables the deceleration function of the harmonic reducer. Through this design, the double steel wheel harmonic reducer can achieve the expected deceleration effect while maintaining a high transmission efficiency.

[0012] Furthermore, a crossed roller bearing is provided between the first steel wheel and the second steel wheel, and the first steel wheel is rotationally connected to the second steel wheel via the crossed roller bearing. The crossed roller bearing can provide high rigidity and high load-carrying capacity in a small space, which helps to stably and accurately transmit torque. By setting the crossed roller bearing between the first steel wheel and the second steel wheel, a stable rotational connection between the two is achieved. This design not only improves the transmission efficiency and stability of the reducer but also saves space, meeting the requirements of miniaturization and lightweight of the reducer.

[0013] Furthermore, the wave generator includes a cam and a flexible bearing sleeved outside the cam. The flexspline assembly is sleeved on the flexible bearing. The cam is of an elliptical structure. The rotation of the cam drives the flexible bearing to produce elastic deformation, and the flexible bearing drives the flexspline assembly to produce elastic deformation and become elliptical. The major axis of the flexspline assembly meshes with the first steel wheel and / or the second steel wheel. The cam and the flexible bearing in the wave generator are used in combination. The elliptical structure of the cam generates a deformation force through rotation, and the flexible bearing transmits this deformation force to the flexspline assembly, causing the flexspline assembly to produce elastic deformation and become elliptical. The meshing of the major axis of the flexspline assembly with the steel wheel assembly ensures the effectiveness and stability of the transmission. Through this design, the flexspline assembly can achieve elastic deformation and mesh with the steel wheel assembly in a smaller volume, thus solving the technical problem of how to achieve elastic deformation of the flexspline assembly and mesh it with the steel wheel assembly in the harmonic reducer.

[0014] Furthermore, the radial clearance of the flexible bearing is less than 50 μm. An increase in the radial clearance results in a decrease in the number of load-bearing balls in the two load zones of the long axis of the flexible bearing, a deterioration in the bearing support performance, and an increase in the contact force. The radial clearance has a greater impact on the deformation of the ring, and the difference between the ring deformation displacement and the designed harmonic deformation amount increases with the increase of the clearance, resulting in a reduction in the transmission performance. Therefore, a smaller value of the radial clearance should be selected as much as possible during the design of the flexible bearing.

[0015] Furthermore, the first steel wheel and the second steel wheel are made of 40Cr steel. The first steel wheel and the second steel wheel are made of 40Cr steel. This material selection can improve the strength and wear resistance of the reducer, ensuring its reliability and performance stability during long-term use. By using 40Cr steel material, the reducer can maintain good performance in a high-load and high-frequency working environment, thus effectively solving the high requirements for the reducer material of humanoid robots under complex working conditions.

[0016] A humanoid robot includes the double steel wheel harmonic reducer described in any one of the above. The humanoid robot further includes a torso component, limb components, and joint components. The limb components are connected to the torso component via the joint components; the joint components include a driving motor, and the output shaft of the driving motor is connected to the double steel wheel harmonic reducer. The driving motor drives the limb components to move relative to the torso component via the double steel wheel harmonic reducer. By integrating the double steel wheel harmonic reducer, this humanoid robot enables the driving motor to efficiently drive the limb components to move relative to the torso component. The high transmission efficiency, small size, and light weight of the double steel wheel harmonic reducer make it very suitable for use in robot joints with limited space and requiring high-efficiency transmission. Through this design, the robot can maintain or improve its motion performance and flexibility while reducing its size and weight. This integration method not only improves the overall efficiency and flexibility of the robot but also reduces costs and occupied space.

[0017] Advantages of the present invention: By adopting a double steel wheel structure and a flexible gear component, this technical solution realizes the miniaturization and lightweight of the harmonic reducer, while ensuring high transmission efficiency and transmission smoothness. The wave generator drives the steel wheels to mesh and transmit power through the flexible gear component, effectively solving the noise problem of the reducer. The overall design enables the reducer to achieve higher torque output within a smaller volume, meeting the strict requirements for the performance of the reducer in the field of robotics. Description of the Drawings

[0018] Figure 1 It is an exploded schematic view of a double steel wheel harmonic reducer for a humanoid robot of the present invention;

[0019] Figure 2 It is a structural schematic view of a double steel wheel harmonic reducer for a humanoid robot of the present invention;

[0020] Figure 3 This is a schematic cross-sectional view of a double steel wheel harmonic reducer for a humanoid robot according to the present invention;

[0021] Figure 4 This is a schematic cross-sectional view of the steel wheel assembly of the present invention;

[0022] Figure 5 is Figure 1 a partial schematic view of A in

[0023] Figure 6 is Figure 4 a partial schematic view of B in

[0024] Figure 7 is Figure 4 a partial schematic view of C in

[0025] Reference numerals include:

[0026] 1, steel wheel assembly; 2, flexspline assembly; 3, wave generator; 4, first steel wheel; 5, second steel wheel; 6, first internal tooth structure; 7, second internal tooth structure; 8, external tooth structure; 9, needle roller; 10, receiving groove; 11, crossed roller bearing; 12, flexible bearing; 13, cam. Detailed implementation manners

[0027] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following describes in detail the specific implementation manners, structures, features and their effects of the present invention in combination with the accompanying drawings and preferred embodiments.

[0028] Please refer to Figures 1 to 7As shown in the figure, a double steel wheel harmonic reducer for a humanoid robot according to the present invention includes a steel wheel assembly 1, a flexspline assembly 2, and a wave generator 3. The steel wheel assembly 1 includes a first steel wheel 4 and a second steel wheel 5. The first steel wheel 4 and the second steel wheel 5 are annular structures. The flexspline assembly 2 is placed in the annular accommodating cavity of the first steel wheel 4 and the second steel wheel 5. A first internal tooth structure 6 is formed on the inner side of the first steel wheel 4, and a second internal tooth structure 7 is formed on the inner side of the second steel wheel 5. The flexspline assembly 2 is an annular structure, and an external tooth structure 8 meshing with the first internal tooth structure 6 and the second internal tooth structure 7 is formed on the outer side of the flexspline assembly 2. There is a tooth number difference between the first internal tooth structure 6 and / or the second internal tooth structure 7 and the external tooth structure 8. The wave generator 3 is used in cooperation with the flexspline assembly 2, and the wave generator 3 drives the first steel wheel 4 and / or the second steel wheel 5 to engage and transmit power through the flexspline assembly 2. By adopting the double steel wheel structure and the flexspline assembly 2, this technical solution realizes the miniaturization and light weight of the harmonic reducer, while ensuring high transmission efficiency and transmission stability. The wave generator 3 drives the steel wheels to engage and transmit power through the flexspline assembly 2, effectively solving the noise problem of the reducer. The overall design enables the reducer to achieve higher torque output within a smaller volume, meeting the strict requirements for the performance of the reducer in the robot field.

[0029] Furthermore, in the present application, it is also proposed that the internal tooth structure is a needle roller 9. There are multiple groups of needle rollers 9, and the multiple groups of needle rollers 9 are arranged circumferentially along the inner sides of the first steel wheel 4 and the second steel wheel 5. Accommodating grooves 10 for accommodating the needle rollers 9 are provided on the inner sides of the first steel wheel 4 and the second steel wheel 5, and the needle rollers 9 are rotatably arranged on the first steel wheel 4 and the second steel wheel 5 via the accommodating grooves.

[0030] By circumferentially arranging multiple groups of needle rollers 9 along the inner sides of the first steel wheel 4 and the second steel wheel 5, the flexspline assembly 2 and the steel wheel assembly 1 are engaged and transmitted through the needle rollers 9, converting the sliding friction of the tooth engagement between the original flexible gear and the rigid gear into rolling friction, effectively reducing wear, thereby increasing the service life of the reducer. After long-term use, it can also maintain high-precision speed reduction transmission. The needle rollers 9 can rotate freely in the accommodating grooves 10, but cannot be separated from the accommodating grooves 10. A limiting structure can be installed on the reducer to limit the separation of the needle rollers 9 from the accommodating grooves 10.

[0031] The structural design of the needle rollers 9 can have various implementation methods. For example, the needle rollers 9 can be made of high-strength alloy materials to ensure their durability under high loads. The design of the accommodating grooves 10 can be precisely machined according to the size of the needle rollers 9 to ensure that the needle rollers 9 can rotate freely therein without separation. The limiting structure can be in the form of a snap ring, a baffle, etc., to ensure that the needle rollers 9 do not fall off during use. In addition, the number and arrangement of the needle rollers 9 can be optimized according to specific load requirements to achieve the best transmission effect.

[0032] By adopting the needle roller 9 as the internal tooth structure, this application converts the original sliding friction into rolling friction, effectively reducing the wear of the reducer, improving the transmission efficiency and the service life of the reducer. Compared with the prior art, the technical solution of this application can maintain high-precision speed reduction transmission after long-term use, and is applicable to application scenarios with high requirements for the performance of the reducer, such as humanoid robots. Therefore, this technical solution has significant advantages in improving the stability and transmission efficiency of the harmonic reducer.

[0033] Furthermore, this application also proposes that the needle roller 9 of the first steel wheel 4 is inclined, and the included angle between the length direction of the needle roller 9 of the first steel wheel 4 and the length direction of the first steel wheel 4 is 0.1° - 6°.

[0034] In order to improve the meshing efficiency between the flexspline assembly 2 and the first steel wheel 4, this application inclines the needle roller 9 of the first steel wheel 4, so that an included angle of 0.1° - 6° is formed between the length direction of the needle roller 9 and the length direction of the first steel wheel 4. This design can effectively solve the warping problem caused by the elastic deformation of the flexspline assembly 2 during rotation, ensure the stable meshing between the first internal tooth structure 6 and the external tooth structure 8, and thus extend the service life of the harmonic reducer.

[0035] Specifically, the inclination of the needle roller 9 of the first steel wheel 4 can be achieved in various ways. For example, an inclination angle can be set in the installation hole of the needle roller 9 of the first steel wheel 4, so that the needle roller 9 automatically forms the required included angle during installation. Another implementation method is to improve the structural design of the needle roller 9 itself, so that the required inclination angle is naturally formed when it is installed on the first steel wheel 4. In addition, the overall structure of the first steel wheel 4 can also be adjusted to make the needle roller 9 installation groove on the inner side show the required inclination angle.

[0036] Furthermore, this application also proposes that the needle roller 9 of the second steel wheel 5 is inclined, and the included angle between the length direction of the needle roller 9 of the second steel wheel 5 and the length direction of the second steel wheel 5 is 174° - 179.9°. During the rotation of the flexspline assembly 2, elastic deformation will occur, and the free ends on both sides of the flexspline assembly 2 will warp due to the deformation, causing the first internal tooth structure 6 to disengage from the external tooth structure 8. This technical feature improves the meshing efficiency between the external tooth structure 8 of the flexspline assembly 2 and the second external tooth structure 8 of the second steel wheel 5 by inclining the needle roller 9, thereby extending the service life of the harmonic reducer.

[0037] Furthermore, this application also proposes that the number of teeth of the internal tooth structure of the first steel wheel 4 is the same as that of the external tooth structure 8, and the difference in the number of teeth between the internal tooth structure and the external tooth structure 8 of the second steel wheel 5 is 2.

[0038] The number of teeth of the internal tooth structure of the first steel gear 4 is the same as that of the external tooth structure 8, which means that during the meshing process of the first steel gear 4 and the flexspline assembly 2, there will be no tooth number difference, thus ensuring the stability of the transmission. The tooth number difference between the internal tooth structure and the external tooth structure 8 of the second steel gear 5 is 2. This specific tooth number difference design can achieve the speed reduction function of the harmonic reducer. Through this design, the double steel gear harmonic reducer can achieve the expected speed reduction effect while maintaining a high transmission efficiency.

[0039] Specifically, the number of teeth of the internal tooth structure of the first steel gear 4 is the same as that of the external tooth structure 8. Such a design ensures that there is no tooth number difference during the meshing process of the first steel gear 4 and the flexspline assembly 2, guaranteeing the smoothness and stability of the transmission. The tooth number difference between the internal tooth structure of the second steel gear 5 and the external tooth structure 8 is 2. This design enables the flexspline assembly 2 to generate corresponding deformations under the action of the wave generator 3, thereby achieving the speed reduction function. Through this specific tooth number difference design, it is ensured that the double steel gear harmonic reducer can achieve the expected speed reduction effect while maintaining a high transmission efficiency.

[0040] Furthermore, the present application also proposes that a crossed roller bearing 11 is provided between the first steel gear 4 and the second steel gear 5, and the first steel gear 4 is rotationally connected to the second steel gear 5 via the crossed roller bearing 11.

[0041] By providing the crossed roller bearing 11 between the first steel gear 4 and the second steel gear 5, a stable rotational connection between the two is achieved. The crossed roller bearing 11 can provide high rigidity and high load-carrying capacity in a relatively small space, which helps to stably and accurately transmit torque. This design not only improves the transmission efficiency and stability of the reducer, but also saves space and meets the requirements of miniaturization and lightweight of the reducer.

[0042] The crossed roller bearing 11 can be arranged in various ways. For example, different types of crossed roller bearings 11 can be selected, such as cylindrical roller bearings, spherical roller bearings, etc., to adapt to different load-carrying requirements and space limitations. Specifically, appropriate roller materials, such as high-strength steel or ceramic materials, can be selected according to actual needs to improve the wear resistance and service life of the bearing. In addition, the lubrication method of the crossed roller bearing 11 can also be optimized according to the actual application situation, such as using oil lubrication or grease lubrication, to ensure the stable operation of the bearing under high loads.

[0043] Furthermore, the present application also proposes that the wave generator 3 includes a cam 13 and a flexible bearing 12 sleeved outside the cam 13. The flexspline assembly 2 is sleeved on the flexible bearing 12. The cam 13 is of an elliptical structure. The rotation of the cam 13 drives the flexible bearing 12 to generate elastic deformation, and the flexible bearing 12 drives the flexspline assembly 2 to generate elastic deformation and become elliptical. The major axis of the flexspline assembly 2 meshes with the first steel gear 4 and / or the second steel gear 5.

[0044] The cam 13 and the flexible bearing 12 in the wave generator 3 are used together. The elliptical structure of the cam 13 generates a deformation force by rotating, and the flexible bearing 12 transmits this deformation force to the flexible wheel assembly 2, so that the flexible wheel assembly 2 is elastically deformed and becomes elliptical. The engagement of the long axis of the flexible wheel assembly 2 with the steel wheel assembly 1 ensures the effectiveness and stability of the transmission. Through this design, the flexible wheel assembly 2 can achieve elastic deformation and mesh with the steel wheel assembly 1 in a smaller volume, thereby solving the technical problem of how to achieve elastic deformation of the flexible wheel assembly 2 and mesh with the steel wheel assembly 1 in the harmonic reducer.

[0045] Specifically, the elliptical structure of the cam 13 generates a periodic deformation force through rotation, and this deformation force is transmitted to the flexible wheel assembly 2 through the flexible bearing 12, causing it to produce corresponding elastic deformation. After being subjected to this deformation force, the flexible wheel assembly 2 presents an elliptical shape, and the long axis part is engaged with the steel wheel assembly 1. The elastic deformation ability of the flexible wheel assembly 2 is achieved through material selection and structural design. For example, materials with high elastic modulus and optimized geometric structure design can be used to ensure the accuracy and stability of deformation.

[0046] Furthermore, the present application also proposes that the radial clearance of the flexible bearing 12 is less than 50 μm. The increase in radial clearance leads to a decrease in the number of load-bearing balls in the two load zones of the long axis of the flexible bearing 12, a deterioration in the bearing support performance, and an increase in the contact force. The radial clearance has a great influence on the deformation of the ring, and the difference between the deformation displacement of the ring and the designed harmonic deformation increases with the increase in the clearance, resulting in a decrease in the transmission performance. Therefore, a radial clearance with a smaller value should be selected as much as possible during the design of the flexible bearing 12.

[0047] Specifically, the radial clearance of the flexible bearing 12 is 30 μm.

[0048] The performance parameters of the flexible bearing 12 in this embodiment are measured, wherein the radial clearances of the flexible bearing 12 are set to 0, 20, 30, 40, and 50 μm, respectively. The influence of different radial clearances on the elastic deformation of the flexible bearing 12 structure and the change of the contact force between the steel ball and the ring are analyzed, and the deformation and mechanical properties of the flexible bearing 12 under different radial clearances are obtained. The contact force (N) between the steel ball and the outer ring of the flexible bearing 12 with different radial clearances is shown in the following table:

[0049]

[0050] The contact forces (N) between the steel ball and the odd and even bearing areas of the outer ring of the flexible bearing 12 with different radial clearances are shown in the following table:

[0051]

[0052] The differences between the outer ring node displacements of the flexible bearings 12 with different radial clearances and the design values (mm) are shown in the following table:

[0053]

[0054]

[0055] Comparing the above data, it can be seen that as the radial clearance increases, the number of supporting steel balls of the flexible bearing 12 decreases, the overall supporting performance of the bearing deteriorates, and the peak contact forces between the steel balls and the raceway in the odd and even supporting regions increase. When the clearance is 50μm, the number of steel balls in the odd and even supports decreases to 3 and 4, which increases the risk of damage to the bearing raceway to a certain extent. And the radial clearance also reduces the elastic deformation transfer ability of the flexible bearing 12, which has a greater impact on the elastic deformation of the structure. Due to the certain penetration amount in the calculation of the contact force by the impact function, under the required deformation of 0.4mm, the maximum difference between the raceway deformation displacement and the theoretical deformation at 0μm clearance is 12.34μm, and the error is less than 3%; as the radial clearance increases, the difference between the raceway deformation displacement and the theoretical deformation also gradually increases. When the clearances are 40μm and 50μm, affected by the radial clearance, the maximum differences between the raceway node displacements of the flexible bearing 12 and the theory are 65.643μm and 79.296μm respectively, and the maximum errors with the theoretical deformation amount are 16.41% and 19.824%. This is because the existence of the clearance makes the pre-deformation process first eliminate the clearance, and then the interaction between the steel balls and the raceway causes the structural elastic deformation of the outer raceway of the bearing. The existence of the radial clearance will make the internal load-bearing performance of the flexible bearing 12 deteriorate, the risk of damage increase, and the difference between the raceway deformation displacement and the theory increase, thus affecting the transmission performance of the bearing. Therefore, in the flexible bearing 12, the value of the radial clearance should be selected as small as possible, even 0 clearance.

[0056] In this embodiment, the radial clearance of the flexible bearing 12 is 30μm, which can not only ensure the transmission performance of the flexible bearing 12, but also avoid the use of high-precision machine tools and reduce the production cost.

[0057] Furthermore, the present application also proposes that the first steel wheel 4 and the second steel wheel 5 are made of 40Cr steel.

[0058] The first steel wheel 4 and the second steel wheel 5 are made of 40Cr steel. This material selection can improve the strength and wear resistance of the reducer, ensuring its reliability and performance stability during long-term use. By using 40Cr steel material, the reducer can maintain good performance in a high-load and high-frequency working environment, thus effectively solving the high requirements for the reducer material of the humanoid robot under complex working conditions.

[0059] The wear resistance performance parameters of the steel wheel assembly 1 in this embodiment are measured. Three steel wheel assemblies 1 made of different steels are selected, with the grades being 2Cr13 stainless steel, 40Cr medium carbon alloy steel, and 45 carbon steel, hereinafter simply referred to as 2Cr13, 40Cr, and 45 steel. The change rules of the hardness, friction factor, and wear area of the steel wheel assemblies 1 made of different steels are analyzed to obtain the wear resistance performance of the steel wheel assemblies 1 made of different steels. The hardness, friction factor, and wear area of the steel wheel assemblies 1 made of different steels are shown in the following table:

[0060]

[0061] Comparing the above data, the average hardness of 45 steel is 22.2 HRC, which is 29.3% lower than the hardness level of 2Cr13 and 27.0% lower than the hardness level of 40Cr. The average friction factor levels of 2Cr13, 40Cr, and 45 steel are similar. The wear areas of 40Cr, 2Cr13, and 45 steel increase in turn, being 1645, 5008, and 6535 μm 2 . The wear mechanism of 2Cr13 is adhesive wear, and those of 40Cr and 45 steel are abrasive wear. The abrasive wear mechanism of 40Cr shows better wear resistance than the adhesive wear of 2Cr13. The hardness difference between 45 steel and the friction pair GCr15 is 42.8 HRC, and severe abrasive wear appears on the surface of 45 steel, with the worst wear resistance performance.

[0062] A humanoid robot includes a double steel wheel harmonic reducer. The humanoid robot includes a torso component, limb components, and joint components. The limb components are connected to the torso component through the joint components. The joint components include a driving motor, and the output shaft of the driving motor is connected to the double steel wheel harmonic reducer. The driving motor drives the limb components to move relative to the torso component through the double steel wheel harmonic reducer.

[0063] By integrating the double steel wheel harmonic reducer, this humanoid robot enables the driving motor to efficiently drive the limb components to move relative to the torso component. The characteristics of the double steel wheel harmonic reducer, such as high transmission efficiency, small size, and light weight, make it very suitable for use in robot joints with limited space and requiring high-efficiency transmission. Through this design, the robot can reduce its size and weight while maintaining or improving its motion performance and flexibility. This integration method not only improves the overall efficiency and flexibility of the robot but also reduces costs and occupied space.

[0064] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the above-disclosed technical content without departing from the technical solution of the present invention. However, as long as it does not depart from the technical solution content of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A double steel wheel harmonic reducer for a humanoid robot, characterized in that: The invention comprises a steel wheel assembly (1), a flexible wheel assembly (2) and a wave generator (3); the steel wheel assembly (1) comprises a first steel wheel (4) and a second steel wheel (5); the first steel wheel (4) and the second steel wheel (5) are annular structures; the flexible wheel assembly (2) is arranged in an annular accommodating cavity of the first steel wheel (4) and the second steel wheel (5); a first inner tooth structure (6) is formed on the inner side of the first steel wheel (4); a second inner tooth structure (7) is formed on the inner side of the second steel wheel (5); the flexible wheel assembly (2) is an annular structure; an outer tooth structure (8) meshing with the first inner tooth structure (6) and the second inner tooth structure (7) is formed on the outer side of the flexible wheel assembly (2); the first inner tooth structure (6) and / or the second inner tooth structure (7) have a difference in the number of teeth with the outer tooth structure (8); the wave generator (3) is used in conjunction with the flexible wheel assembly (2); the wave generator (3) drives the first steel wheel (4) and / or the second steel wheel (5) to mesh and transmit via the flexible wheel assembly (2).

2. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 1, characterized in that: The inner tooth structure is a needle roller (9), and the needle roller (9) is provided in a plurality of groups. The plurality of groups of needle rollers (9) are arranged along the inner circumference of the first steel wheel (4) and the second steel wheel (5). The inner sides of the first steel wheel (4) and the second steel wheel (5) are provided with receiving grooves (10) for receiving the needle rollers (9), and the needle rollers (9) are rotatably arranged on the first steel wheel (4) and the second steel wheel (5) via the receiving grooves.

3. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 2, characterized in that: The needle roller (9) of the first steel wheel (4) is arranged tilted, and the angle between the length direction of the needle roller (9) of the first steel wheel (4) and the length direction of the first steel wheel (4) is 0.1°-6°.

4. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 3, characterized in that: The needle roller (9) of the second steel wheel (5) is arranged obliquely, and the angle between the length direction of the needle roller (9) of the second steel wheel (5) and the length direction of the second steel wheel (5) is 174°-179.9°.

5. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 1, characterized in that: The number of teeth of the inner tooth structure of the first steel wheel (4) is the same as the number of teeth of the outer tooth structure (8), and the difference in the number of teeth between the inner tooth structure and the outer tooth structure (8) of the second steel wheel (5) is 2.

6. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 1, characterized in that: A cross roller bearing (11) is provided between the first steel wheel (4) and the second steel wheel (5), and the first steel wheel (4) is rotatably connected to the second steel wheel (5) via the cross roller bearing (11).

7. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 1, characterized in that: The wave generator (3) comprises a cam (13) and a flexible bearing (12) sleeved outside the cam (13); the flexible wheel assembly (2) is sleeved on the flexible bearing (12); the cam (13) is an elliptical structure; the rotation of the cam (13) drives the flexible bearing (12) to produce elastic deformation; the flexible bearing (12) drives the flexible wheel assembly (2) to produce elastic deformation and become elliptical; the long axis of the flexible wheel assembly (2) is meshed with the first steel wheel (4) and / or the second steel wheel (5).

8. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 7, characterized in that: The radial clearance of the flexible bearing (12) is less than 50 μm.

9. The double-steel-wheel harmonic reducer for a humanoid robot according to claim 1, characterized in that: The first steel wheel (4) and the second steel wheel (5) are made of 40Cr steel.

10. A humanoid robot, characterized in that: The humanoid robot comprises the double-steel-wheel harmonic reducer as described in any one of claims 1 to 9, wherein the humanoid robot further comprises a trunk component, a limb component and a joint component, wherein the limb component is connected to the trunk component via the joint component; the joint component comprises a drive motor, wherein the output shaft of the drive motor is connected to the double-steel-wheel harmonic reducer, and the drive motor drives the limb component to move relative to the trunk component via the double-steel-wheel harmonic reducer.

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