Composite bearing, harmonic driving device and automatic working device

Abstract

The utility model discloses a composite bearing, harmonic drive device and automatic working device, the composite bearing comprises a roller pin, a cross roller, a bearing inner ring and a bearing outer ring which are coaxially arranged, the bearing outer ring is sleeved on the outer side of the bearing inner ring, and the roller pin and the cross roller are respectively arranged between the bearing inner ring and the bearing outer ring in a surrounding mode. And the roller pins and the crossed rollers are arranged in series along the axial direction. According to the composite bearing, the roller pin and the crossed roller are combined for use, so that the composite bearing has good radial load bearing capacity, meanwhile, the roller pin and the crossed roller are uniformly fixed through the bearing inner ring and the bearing outer ring, radial run-out is avoided, the bending moment resistance of the composite bearing is improved, and then the service life of the composite bearing is prolonged. The harmonic driving device manufactured by using the composite bearing has good bending moment resistance. Furthermore, the automatic working device using the composite bearing or the harmonic driving device has good bending moment resistance, high-speed stamping can be achieved, and the environment adaptability of the automatic working device is improved.

Description

Technical Field

[0001] This utility model relates to the field of bearings, and in particular to a composite bearing, a harmonic drive device, and an automatic working device. Background Technology

[0002] Traditional harmonic drive devices often use a single type of bearing, which is insufficient to simultaneously meet the load-bearing requirements of high radial load, axial load, and overturning moment. While crossed roller bearings have high rigidity, sliding friction between the rollers can easily lead to temperature rise; needle roller bearings have strong radial load capacity but insufficient axial stiffness. Placing needle roller bearings and crossed roller bearings separately inside the reducer would increase the reducer's length, failing to meet the requirements of compact equipment and imposing extremely high precision requirements on the machined parts. Since neither type of bearing has radial runout, over-precision machining can easily cause the reducer to seize up. Utility Model Content

[0003] The technical problem to be solved by this utility model embodiment is to provide a composite bearing, a harmonic drive device, and an automatic working device that can improve the equipment's environmental adaptability.

[0004] To solve the above-mentioned technical problems, this utility model provides a composite bearing, characterized in that the composite bearing includes coaxially arranged needle rollers, crossed rollers, an inner bearing ring, and an outer bearing ring, the outer bearing ring being sleeved on the outside of the inner bearing ring, the needle rollers and the crossed rollers being respectively arranged around the inner bearing ring and the outer bearing ring, and the needle rollers and the crossed rollers being arranged in series along the axial direction.

[0005] In one feasible implementation, the inner ring of the bearing has cross roller inner raceways and needle roller inner raceways spaced axially on its outer circumferential sidewall, and the outer ring of the bearing has cross roller outer raceways and needle roller outer raceways spaced axially on its inner circumferential sidewall. The outer ring of the bearing is fitted over the outer side of the inner ring of the bearing. The cross roller inner raceways and cross roller outer raceways are joined together to form cross roller raceways, and the needle roller inner raceways and needle roller outer raceways are joined together to form needle roller raceways. Several cylindrical rollers are rotatably embedded in the cross roller raceways, and two adjacent cylindrical rollers are arranged in a cross-shaped configuration. Needles are rotatably embedded in the needle roller raceways.

[0006] Accordingly, this utility model also provides a harmonic drive device, including the composite bearing as described in any of the foregoing descriptions.

[0007] In one feasible implementation, the harmonic drive device further includes, from the inside out, a wave generating component, a flexible wheel, a steel wheel, and a housing assembly, wherein the flexible wheel meshes with the steel wheel, the wave generating component is used to drive the flexible wheel to rotate and thus drive the steel wheel to rotate, and the composite bearing is disposed between the flexible wheel and the housing assembly.

[0008] In one feasible implementation, the wave generating assembly includes a first bearing and a cam, the cam being disposed within the flexure, the first bearing being disposed between the cam and the flexure, and the composite bearing being disposed on the outer side of the flexure at a position corresponding to the first bearing.

[0009] In one feasible implementation, the wave generating assembly further includes a second bearing, which is disposed on the same side of the flexure as the first bearing, and is located at a position corresponding to the meshing of the flexure and the steel wheel.

[0010] In one feasible implementation, the harmonic drive device further includes a motor connected to the wave generating component for driving the wave generating component to rotate.

[0011] Accordingly, this utility model also provides an automatic working device, including the composite bearing or the harmonic drive device as described above.

[0012] In one feasible implementation, the automatic working device further includes a main body and four drive wheels, each of which is connected to the main body via the harmonic drive device.

[0013] In one feasible implementation, the automatic working device further includes a connecting rod, through which the two drive wheels in front of the automatic working device along the running direction are connected.

[0014] Implementing this utility model has the following beneficial effects:

[0015] This application provides a composite bearing, a harmonic drive device, a robot joint, and a four-wheel drive vehicle. The composite bearing, by combining needle rollers and crossed rollers, possesses excellent radial load-bearing capacity. Simultaneously, the needle rollers and crossed rollers are uniformly fixed by the inner and outer rings of the bearing, preventing radial runout and improving the bending moment resistance of the composite bearing. Consequently, the harmonic drive device made using this composite bearing exhibits excellent bending moment resistance. Furthermore, the automated working device using this composite bearing or harmonic drive device demonstrates excellent bending moment resistance, enabling high-speed stepping and improving the environmental adaptability of the automated working device.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application, and do not constitute an undue limitation of this application.

[0018] Figure 1 This is a partial cross-sectional view of the composite bearing shown in some embodiments of this utility model;

[0019] Figure 2 This is an overall cross-sectional view of the harmonic drive device shown in some embodiments of this utility model;

[0020] Figure 3 This is an exploded view of a harmonic drive device shown in some embodiments of this utility model;

[0021] Figure 4 This is a schematic diagram of the overall structure of the automatic working device shown in some embodiments of this utility model.

[0022] The reference numerals in the figure:

[0023] 100-Harmonic Drive Device

[0024] 10-Composite bearing, 11-Needle roller, 12-Crossed roller, 13-Bearing inner ring, 14-Bearing outer ring.

[0025] 21-First bearing, 22-Cam, 23-Second bearing, 24-Third bearing, 30-Flexible wheel, 40-Steel wheel, 50-Housing assembly, 60-Motor

[0026] 1000 - Automatic working device, 200 - Main body, 300 - Drive wheel, 400 - Connecting rod. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0028] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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 this utility model.

[0029] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0030] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0031] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] Please refer to Figure 1 This application provides a composite bearing 10. The composite bearing 10 includes coaxially arranged needle rollers 11, crossed rollers 12, an inner bearing ring 13, and an outer bearing ring 14. The outer bearing ring 14 is sleeved on the outside of the inner bearing ring 13. The needle rollers 11 and the crossed rollers 12 are respectively arranged around the inner bearing ring 13 and the outer bearing ring 14, and the needle rollers 11 and the crossed rollers 12 are arranged in series along the axial direction.

[0033] The composite bearing 10 provided in this application combines the advantages of both needle roller bearings 11 and crossed roller bearings 12 by using needle rollers 11 and crossed rollers 12 together. The needle roller bearing 11 is characterized by a large radial load. There is a certain gap between the needle rollers 11 and the crossed rollers 12. When the reducer experiences radial impact, the impact force is transmitted to the bearing through the output shaft and converted into a bending moment, which is then converted into a radial static load of the bearing. The large radial force that the needle rollers 11 can withstand, as well as the distance between the needle rollers 11 and the crossed rollers 12, will form a lever arm, thereby increasing the bending moment resistance of the entire bearing and improving the bending moment resistance performance of the reducer. However, if the needle roller bearing 11 and the crossed roller bearing 12 are placed separately inside the reducer, it will increase the length of the reducer and require extremely high precision in the machining parts. Neither of them has radial runout, which can easily lead to the reducer jamming due to over-precision.

[0034] In one feasible implementation, the inner ring 13 of the bearing has cross roller inner raceways 12 and needle roller inner raceways spaced axially on its outer circumferential outer wall. The outer ring 14 of the bearing has cross roller outer raceways 12 and needle roller outer raceways spaced axially on its inner circumferential inner wall. The outer ring 14 is fitted over the outer side of the inner ring 13. The cross roller inner raceways and cross roller outer raceways are joined together to form the cross roller 12 raceway. The needle roller inner raceways and needle roller outer raceways are joined together to form the needle roller 11 raceway. A plurality of cylindrical rollers are rotatably embedded in the cross roller 12 raceways. Adjacent cylindrical rollers are arranged in a cross-shaped configuration, and the needle rollers 11 are rotatably embedded in the needle roller 11 raceways. The cross-shaped arrangement of cylindrical rollers forms a stable mesh support, specifically designed to handle complex overturning moments and bidirectional axial forces, much like a cable-stayed bridge structure, achieving torque balance through force decomposition and transmission. Densely arranged slender needle rollers 11 form a high-density support surface, focused on absorbing radial impact loads, similar to the buffering effect of a spring array, making it particularly suitable for withstanding high-frequency vibrations or instantaneous impacts. The two-section design avoids the overload risk of a single bearing while achieving intelligent load distribution. This structural design allows the needle rollers 11 and cross rollers 12 to be stably fixed between the inner ring 13 and the outer ring 14 of the bearing, facilitating machining and installation. The separate raceway design creates independent lubrication environments for the two bearing sections: the cross roller 12 area can use high-viscosity grease lubrication to enhance boundary lubrication, while the needle roller 11 area uses more fluid oil lubrication for rapid heat dissipation, like customizing a maintenance plan for different moving parts, reducing overall temperature rise and extending service life. The separate machining and splicing positioning design of the inner and outer ring raceways makes it easier to control local geometric accuracy (such as roundness and straightness) compared to a monolithic raceway. Even if there are micron-level deviations in a single raceway segment, they can be adjusted through selective assembly, similar to precise alignment in a jigsaw puzzle, reducing the cost of ultra-precision machining. Furthermore, the crossed roller 12 raceway and the needle roller 11 raceway can be machined in steps: first, the complex curved surface of the crossed roller 12 raceway is completed with a high-precision grinding machine, and then the needle roller 11 raceway is machined with a special tool, avoiding the tool interference problem in traditional composite raceway machining. It's like drawing a fine brush painting in stages, improving the yield rate.

[0035] In one feasible implementation, the inner raceway of the crossed roller 12 and the inner raceway of the needle roller 11, as well as the outer raceway of the crossed roller 12 and the outer raceway of the needle roller 11, can also be formed on the raceway component, which is then fixedly connected and assembled with the bearing to form a composite bearing 10. That is to say, it is not limited to the raceways being formed on the inner ring 13 and the outer ring 14 of the bearing.

[0036] Accordingly, please refer to Figure 2 and Figure 3This application also provides a harmonic drive device 100, which includes the aforementioned composite bearing 10. Thus, the harmonic drive device 100 of this application, by using the aforementioned composite bearing 10, possesses all the advantages of the composite bearing 10.

[0037] In one feasible implementation, the harmonic drive device 100 further includes, from the inside out, a wave generating assembly, a flexible wheel 30, a steel wheel 40, and a housing assembly 50. The flexible wheel 30 meshes with the steel wheel 40, and the wave generating assembly drives the flexible wheel 30 to rotate, thereby causing the steel wheel 40 to rotate. The composite bearing 10 is disposed between the flexible wheel 30 and the housing assembly 50. The housing assembly 50 is formed by assembling several independent sub-housings, which facilitates the assembly of the harmonic drive device 100 and also facilitates its rotation.

[0038] In one feasible implementation, the wave generating assembly includes a first bearing 21 and a cam 22. The cam 22 is disposed inside the flexure 30, and the first bearing 21 is disposed between the cam 22 and the flexure 30. The composite bearing 10 is disposed on the outside of the flexure 30 at a position corresponding to the first bearing 21.

[0039] In one feasible implementation, the first bearing 21 is a deep groove ball bearing. Deep groove ball bearings have a simple design and a low coefficient of friction, which helps improve the working efficiency of the harmonic drive device 100 and reduce energy loss. Deep groove ball bearings can support high rotational speeds, which is crucial for maintaining the stability and reliability of the harmonic drive device 100 during high-speed operation. Deep groove ball bearings provide high rotational accuracy, which is essential for ensuring the precise positioning of the output shaft of the harmonic drive device 100. The design of deep groove ball bearings makes them easy to install and disassemble, simplifying the assembly process of the harmonic drive device 100 and facilitating subsequent maintenance. Although deep groove ball bearings are primarily suitable for bearing radial loads, they can also withstand a certain amount of axial loads. This means they can, to some extent, accommodate forces in different directions that may occur during the operation of the harmonic drive device 100.

[0040] In one feasible implementation, the wave generating assembly further includes a second bearing 23, which is disposed on the same side of the flexible wheel 30 as the first bearing 21, and is located at the position corresponding to the meshing of the flexible wheel 30 and the steel wheel 40. Thus, by providing the second bearing 23, the reliability of the wave generating assembly in driving the flexible wheel 30 to rotate the steel wheel 40 can be further improved.

[0041] Furthermore, the second bearing 23 can also be a deep groove ball bearing. The advantages of choosing a deep groove ball bearing for the second bearing 23 will not be elaborated here. Furthermore, both the first bearing 21 and the second bearing 23 can be deep groove ball bearings. This can improve the consistency of the harmonic drive device 100, facilitate assembly, and improve the operational reliability and efficiency of the harmonic drive device 100.

[0042] In one feasible implementation, the harmonic drive device 100 further includes a motor 60 connected to the wave generating component for driving the wave generating component to rotate.

[0043] In one feasible implementation, the harmonic drive device 100 further includes a third bearing 24 disposed between the motor 60 and the cam 22.

[0044] Furthermore, the motor 60 is a frameless motor 60. The frameless motor 60 has a compact structure, thus saving space and reducing the overall system size. The frameless motor 60 can directly contact other parts of the machine, which allows for more efficient heat dissipation, avoiding overheating problems and potentially extending the motor 60's lifespan. By integrating the motor 60 into the machine's structure, the mechanical rigidity and stability of the entire system can be increased, which is particularly important for high-precision positioning and harmonic reducer applications. Combined with the high precision and large reduction ratio characteristics unique to harmonic drives, using the frameless motor 60 can further optimize the overall system performance, achieving higher efficiency, accuracy, and reliability.

[0045] In one feasible embodiment, the steel wheel 40 includes an outer ring and an inner hollow shaft coaxially arranged. The outer ring and the bottom of the inner hollow shaft are fixedly connected by a flange. The outer ring has a toothed groove corresponding to the flexible wheel 30. The cam 22 is sleeved on the outside of the inner hollow shaft. The first bearing 21, the second bearing 23, the third bearing 24, and the motor 60 are sleeved on the cam 22. The flexible wheel 30 is sleeved on the cam 22 through the second bearing 23 and the third bearing 24. The outer ring of the steel wheel 40 is sleeved on the flexible wheel 30, and the outer teeth of the flexible wheel 30 mesh with the inner teeth of the outer ring of the steel wheel 40. The composite bearing 10 is disposed between the flexible wheel 30 and the housing assembly 50.

[0046] Furthermore, the cam 22 has a flange, the motor 60 is fixed on the flange, and the second bearing 23 and the third bearing 24 are fixed below the flange.

[0047] In one feasible implementation, the harmonic drive device 100 further includes a Hall element electrically connected to the motor 60.

[0048] Accordingly, this application also provides an automatic working device 1000. The automatic working device 1000 includes any of the aforementioned composite bearing 10 or any of the aforementioned harmonic drive device 100. The automatic working device 1000 can be a robot, such as a robotic arm or a bionic robot, and the composite bearing 10 or harmonic drive device 100 can be applied to the robot's joints or other structures. The automatic working device 1000 can also be a mobile robot, such as a wheeled robot like an automatic four-wheel drive vehicle, and the composite bearing 10 or harmonic drive device 100 can be applied to drive the drive wheels of the four-wheel drive vehicle. Specific definitions and applications of robots are not elaborated here. The automatic working device 1000 provided in this application has all the advantages of the aforementioned composite bearing 10 or harmonic drive device 100, which will not be elaborated here.

[0049] In one feasible implementation, the automatic working device 1000 is as follows: Figure 4 The illustrated automatic four-wheel drive vehicle includes an automatic working device 1000 comprising four harmonic drive units 100, a main body 200, and four drive wheels 300. Each drive wheel 300 is connected to the main body 200 via a harmonic drive unit 100. Specifically, the harmonic drive unit 100 is connected to the drive wheel 300 via a flange portion of a steel wheel 40. This significantly improves the bending moment load resistance by utilizing the impact resistance of the harmonic drive units 100, solving the problem of the automatic four-wheel drive vehicle's inability to climb stairs at high speeds and increasing the vehicle's environmental adaptability.

[0050] In one feasible implementation, such as Figure 4 As shown, the automatic working device 1000, i.e., the automatic four-wheel drive vehicle, also includes a connecting rod 400. The two drive wheels 300 at the front along the running direction of the automatic working device 1000 are connected through the connecting rod 400. This solves the problem of the vehicle deviating from its original trajectory due to uneven road surfaces, depressions, gaps, etc. Specifically, the harmonic drive device 100 is connected to the connecting rod 400, and the connecting rod 400 is connected to the main body 200. The harmonic drive device 100 and the drive wheels 300 are fixed together as a wheel set. When the road surface is uneven, the wheel set floats up and down, and is supported on the main body 200. The two wheel sets at the front of the vehicle, i.e., at the front along the running direction of the automatic working device 1000, are hinged, while the two rear wheel sets are supported separately, forming a three-point support structure for the entire vehicle, making it more stable.

[0051] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A composite bearing, characterized in that, The composite bearing includes coaxially arranged needle rollers, crossed rollers, an inner bearing ring, and an outer bearing ring. The outer bearing ring is sleeved on the outside of the inner bearing ring. The needle rollers and crossed rollers are respectively arranged around the inner and outer bearing rings, and the needle rollers and crossed rollers are connected in series along the axial direction.

2. The composite bearing according to claim 1, characterized in that, The inner ring of the bearing has cross roller inner raceways and needle roller inner raceways spaced along its axial direction on its outer circumferential outer sidewall. The outer ring of the bearing has cross roller outer raceways and needle roller outer raceways spaced along its axial direction on its inner circumferential inner sidewall. The outer ring of the bearing is fitted outside the inner ring of the bearing. The cross roller inner raceways and cross roller outer raceways face each other to form cross roller raceways, and the needle roller inner raceways and needle roller outer raceways face each other to form needle roller raceways. Several cylindrical rollers are rotatably embedded in the cross roller raceways, and two adjacent cylindrical rollers are arranged in a cross shape. Needles are rotatably embedded in the needle roller raceways.

3. A harmonic drive device, characterized in that, Including the composite bearing as described in any one of claims 1 to 2.

4. The harmonic drive device according to claim 3, characterized in that, The harmonic drive device further includes, from the inside out, a wave generating component, a flexible wheel, a steel wheel, and a housing component. The flexible wheel meshes with the steel wheel, the wave generating component drives the flexible wheel to rotate and thus drives the steel wheel to rotate, and the composite bearing is disposed between the flexible wheel and the housing component.

5. The harmonic drive device according to claim 4, characterized in that, The wave generating assembly includes a first bearing and a cam. The cam is disposed inside the flexible wheel, and the first bearing is disposed between the cam and the flexible wheel. The composite bearing is disposed on the outer side of the flexible wheel at a position corresponding to the first bearing.

6. The harmonic drive device according to claim 5, characterized in that, The wave generating assembly further includes a second bearing, which is disposed on the same side of the flexible wheel as the first bearing, and the second bearing is disposed at a position corresponding to the meshing of the flexible wheel and the steel wheel.

7. The harmonic drive device according to claim 4, characterized in that, The harmonic drive device also includes a motor, which is connected to the wave generating component and is used to drive the wave generating component to rotate.

8. An automatic working device, characterized in that, Includes the harmonic drive device as described in any one of claims 3 to 7.

9. The automatic working device according to claim 8, characterized in that, The automatic working device also includes The main body and four drive wheels, each of which is connected to the main body via the harmonic drive device.

10. The automatic working device according to claim 9, characterized in that, The automatic working device also includes a connecting rod, through which the two drive wheels in front of the automatic working device along the running direction are connected.

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