Harmonic reducer, mechanical arm and robot

Abstract

A harmonic reducer, a mechanical arm and a robot, the harmonic reducer comprising a circular spline, a flexspline and a wave generator, wherein the wave generator comprises a cam and a flexible bearing; a bearing outer ring is provided on an outer peripheral wall of at least one side of the cam, and the cam is rotationally connected to the bearing outer ring; and an outer peripheral wall of the bearing outer ring is connected to an inner peripheral wall of the circular spline. In the present invention, the bearing outer ring is arranged on an outer peripheral wall of at least one end of the cam, and the cam serves as a bearing inner ring, such that parts and components are reduced; and under the same bearing capacity, the bearing outer ring limits the flexspline and the flexible bearing, a sealing ring is omitted, and no additional connecting component or fixing component needs to be used for fixing the flexspline, thereby simplifying the process and reducing the volume and the weight of the harmonic reducer. The harmonic reducer in the present invention can be directly connected to an electric motor, and no additional bearing is needed, which reduces the axial length when the harmonic reducer is connected to the electric motor, and does not reduce the power of the electric motor, thereby further achieving the aim of miniaturization, and thus the cost is reduced and promotion is facilitated.

Description

Harmonic reducer, robotic arm and robot

[0001] Cross-references

[0002] This application is based on the Chinese patent application with application number 202310689596X and application date June 12, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present invention belongs to the technical field of transmission reduction technology, and in particular relates to a harmonic reducer, a mechanical arm and a robot. Background Art

[0004] A harmonic reducer is a new, high-precision transmission reduction device consisting of three basic components: a wave generator, a flexspline, and a steel pulley. The wave generator creates controllable elastic deformation in the flexspline, which then meshes with the steel pulley to transmit motion and power. This type of reducer offers high torque, a high transmission ratio, light weight, and a compact size. It is widely used in robotics, particularly in collaborative robotic arms, service robots, and other robotics sub-sectors.

[0005] The wave generator is a rod-shaped component with rollers mounted at both ends, forming rolling bearings that press against the inner wall of the flexspline. The flexspline is a thin-walled gear capable of significant elastic deformation, with an inner diameter slightly smaller than the wave generator's long axis. The wave generator is the component that causes the flexspline to undergo controllable elastic deformation. When the wave generator is installed in the flexspline, its cross-section changes from circular to elliptical. The teeth near the ends of its long axis fully engage with the steel wheel, while the teeth near the ends of its short axis completely disengage. The teeth in other sections of the circumference are in a transitional state between engagement and disengagement. As the wave generator rotates continuously in the direction shown, the deformation of the flexspline continuously changes, causing the meshing state between the flexspline and the steel wheel to continuously change, from engagement, engagement, disengagement, disengagement, and reengagement, repeating a cycle. This results in the flexspline slowly rotating relative to the steel wheel in the direction opposite to the wave generator H. During operation, the steel wheel is fixed, and the motor drives the wave generator. The flexspline acts as the driven wheel, outputting rotation and driving the load. During the transmission process, the number of deformation cycles at a point on the flexspline per one revolution of the wave generator is called the wave number, represented by n. The most commonly used types are double-wave and triple-wave. Double-wave transmissions offer low flexspline stress, a simpler structure, and the ability to achieve a large transmission ratio. Therefore, they are the most widely used.

[0006] In the existing technology, the motor is connected to the harmonic reducer through a bearing, and the motor provides power to the harmonic reducer. In the transmission system composed of the motor, bearings and harmonic reducer, the motor, bearings and harmonic reducer are discrete components. Therefore, the integration level is not high and the overall size after connection is too large. At present, miniaturization and integration are an important development direction in the field of robotic arms and even robots. How to further improve the miniaturization and high integration of key components such as harmonic reducers is a key problem facing the development of the industry.

[0007] Summary of the Invention

[0008] (1) Purpose of the invention

[0009] The object of the present invention is to provide a harmonic reducer, a robotic arm and a robot in which a bearing is integrated into the harmonic reducer to further reduce the number of parts, the overall volume, the weight and the complexity of the system.

[0010] (2) Technical solution

[0011] In order to solve the above problems, the present invention provides a harmonic reducer, comprising: a steel wheel, a flexible wheel and a wave generator;

[0012] The steel wheel, the flexible wheel and the wave generator are all annular structures, and the steel wheel, the flexible wheel and the wave generator are assembled in sequence from the outside to the inside;

[0013] The inner peripheral wall of the steel wheel is provided with steel wheel internal teeth, and the outer peripheral wall of the flexible wheel is provided with flexible wheel external teeth meshing with the inner teeth of the steel wheel;

[0014] The wave generator includes a cam and a flexible bearing, wherein the flexible bearing is arranged between the flexible wheel and the cam;

[0015] The outer peripheral wall of at least one side of the cam is provided with a bearing outer ring, the cam is rotatably connected to the bearing outer ring, the outer peripheral wall of the bearing outer ring is connected to the inner peripheral wall of the steel wheel, and one end of the flexible wheel and one end of the flexible bearing are in contact with the bearing outer ring.

[0016] In another aspect of the present invention, preferably, balls are provided between the cam and the bearing outer ring, so that the cam and the bearing outer ring are rotationally connected via the balls.

[0017] In another aspect of the present invention, preferably, the outer ring on one side of the cam in rolling connection with the outer ring of the bearing is provided with a cam annular groove, which is a mounting groove for the ball.

[0018] In another aspect of the present invention, preferably, a bearing mounting position is provided at the connection between the steel wheel and the bearing outer ring.

[0019] In another aspect of the present invention, preferably, the wave generator includes at least two flexible bearings.

[0020] In another aspect of the present invention, preferably, the steel wheel is provided with threaded holes on the end surface and the outer ring.

[0021] In another aspect of the present invention, preferably, the steel wheel includes a first steel wheel and a second steel wheel, the steel wheel internal teeth include a first steel wheel internal teeth and a second steel wheel internal teeth, the first steel wheel inner circumferential wall is provided with the first steel wheel internal teeth, and the second steel wheel inner circumferential wall is provided with the second steel wheel internal teeth. When the number of teeth of the flexible spline external teeth is fixed, by changing the tooth ratio of the first steel wheel internal teeth and the second steel wheel internal teeth, the first steel wheel can be used as an input steel wheel or an output steel wheel, and correspondingly, the second steel wheel can be used as an output steel wheel or an input steel wheel.

[0022] In another aspect of the present invention, preferably, one end of the first steel wheel is provided with a ring-shaped steel wheel boss extending in an annular manner, and the outer peripheral wall of the steel wheel boss is provided with a first V-shaped ring groove; the inner ring of the second steel wheel is provided with a first steel wheel part and a second steel wheel part, and the inner diameter of the first steel wheel part is larger than the inner diameter of the second steel wheel part; the inner peripheral wall of the first steel wheel part of the second steel wheel is provided with a second V-shaped ring groove, which cooperates with the first V-shaped ring groove to form a rectangular ring groove; and also includes a roller, which is arranged in the rectangular ring groove.

[0023] In another aspect of the present invention, preferably, a robotic arm comprises one or more joints, wherein the joints comprise a harmonic reducer as described above.

[0024] In another aspect of the present invention, preferably, a robot comprises the robotic arm as described above. (3) Beneficial effects

[0025] The above technical solution of the present invention has the following beneficial technical effects:

[0026] The present invention provides a bearing outer ring on the outer peripheral wall of at least one side of the cam, and uses the cam as a bearing inner ring. This reduces independent bearing components without increasing the volume of the harmonic reducer. The bearing outer ring and the cam form a bearing structure, which increases the rigidity of the bearing and the high integration of the overall structure, making the harmonic reducer a completely independent individual and increasing the stability and rigidity of the structure. The flexible wheel and the flexible bearing abut against the bearing outer ring, which can limit the flexible wheel and the flexible bearing, reduce the axial movement of the flexible wheel, and improve the stability of the flexible wheel. This integrated design improves the sealing of the structure, reduces the number of sealing rings, and does not require additional structures to seal the grease in the reducer in subsequent use, thereby simplifying the process. The bearing outer ring limits the flexible wheel, eliminating the need for additional connecting components and fixing components to fix the flexible wheel, further simplifying the process and reducing the volume and weight of the harmonic reducer. The harmonic reducer of the present invention can be directly connected to the motor without the need for additional bearings as connecting components, reducing the axial length of the harmonic reducer when connected to the motor, further achieving the purpose of miniaturization, and at the same time reducing the difficulty of coaxiality adjustment of multiple component connections, reducing costs, and facilitating promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a cross-sectional view of a harmonic reducer according to an embodiment of the present invention;

[0028] FIG2 is a schematic diagram of the robot structure according to an embodiment of the present invention;

[0029] FIG3 is a schematic structural diagram of a dual-arm robot according to an embodiment of the present invention;

[0030] FIG4 is a schematic structural diagram of a composite robot according to an embodiment of the present invention;

[0031] FIG5 is an exploded view of the overall structure of an embodiment of the present invention;

[0032] Figure markings: 1: steel wheel, 2: flexible wheel, 3: wave generator, 4: harmonic reducer, 5: robotic arm, 1-1: first steel wheel, 1-2: second steel wheel, 1-3: steel wheel inner teeth, 1-4: bearing mounting position, 1-5: roller, 2-1: flexible wheel outer teeth, 3-1: cam, 3-2: flexible bearing, 3-3: bearing outer ring, 3-4: ball, 1-1-1: steel wheel boss, 1-2-1: first part of steel wheel, 1-2-2: second part of steel wheel, 1-3-1: first steel wheel inner teeth, 1-3-2: second steel wheel inner teeth, 3-1-1: cam boss, 3-1-2: cam annular groove. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0034] The accompanying drawings illustrate schematic diagrams of layer structures according to embodiments of the present invention. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes, relative sizes, and positional relationships of the various regions and layers shown in the figures are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions based on actual needs.

[0035] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the terms "first", "second" and "third" are only used for descriptive purposes and should not be understood as indicating or implying relative importance.

[0037] Example 1

[0038] A harmonic reducer, FIG1 shows a cross-sectional view of a harmonic reducer according to an embodiment of the present invention, and FIG5 shows an exploded view of the overall structure of an embodiment of the present invention, as shown in FIG1 and FIG5, comprising: a steel wheel 1, a flexible wheel 2 and a wave generator 3; the steel wheel 1, the flexible wheel 2 and the wave generator 3 are all annular structures, and the steel wheel 1, the flexible wheel 2 and the wave generator 3 are sequentially assembled from the outside to the inside; the flexible wheel 2 is arranged in the annular receiving cavity of the steel wheel 1, and the wave generator 3 is arranged in the annular receiving cavity of the flexible wheel 2. The specific spacing between the steel wheel 1, the flexible wheel 2 and the wave generator 3 is not limited here. Optionally, in this embodiment, the steel wheel 1, the flexible wheel 2 and the wave generator 3 are tightly fitted.

[0039] The specific structure of the steel wheel 1 is not limited here. Optionally, in this embodiment, the steel wheel 1 includes a first steel wheel 1-1 and a second steel wheel 1-2. The first steel wheel 1-1 and the second steel wheel 1-2 are annular structures. The first steel wheel 1-1 and the second steel wheel 1-2 form an annular receiving cavity. The radial relationship between the first steel wheel 1-1 and the second steel wheel 1-2 is not limited here, nor is the axial relationship between the two. Optionally, the first steel wheel 1-1 and the second steel wheel 1-2 have the same radial length, and the first steel wheel 1-1 and the second steel wheel 1-2 have the same axial length. The connection structure between the first steel wheel 1-1 and the second steel wheel 1-2 may be a cross roller bearing structure. In this embodiment, the connection structure is optionally provided with a ring-shaped steel wheel boss 1-1-1 at one end of the first steel wheel 1-1. The overall size ratio between the steel wheel boss 1-1-1 and the first steel wheel 1-1 is not limited here. Optionally, the steel wheel boss 1-1-1 may be provided at a position biased toward the outer ring of the first steel wheel 1-1, or at a position biased toward the inner ring of the first steel wheel 1-1, or may extend along the center line of the cross section of the first steel wheel 1-1. The outer peripheral wall of the steel wheel boss 1-1-1 is provided with a first V-shaped ring groove, and the positional relationship between the first V-shaped ring groove and the steel wheel boss 1-1-1 is not limited here, nor is the specific shape of the first V-shaped ring groove limited; the inner ring of the second steel wheel 1-2 includes the first steel wheel part 1-2-1 and the second steel wheel part 1-2-2, and the size ratio relationship between the first steel wheel part 1-2-1 and the second steel wheel part 1-2-2 is not limited here, and the inner periphery of the first steel wheel part 1-2-1 is provided with a second V-shaped ring groove, which cooperates with the first V-shaped ring groove to form a rectangular ring groove. Optionally, in this embodiment, the first steel wheel part 1-2-1 and the steel wheel boss 1-1-1 have the same axial length, and the two can fit tightly together, and also include a roller 1-5, which is arranged in the rectangular ring groove formed by the first V-shaped ring groove and the second V-shaped ring groove. Optionally , the roller 1-5 is a cylindrical structure made of metal material, and is cross-mounted in a rectangular annular groove formed by the first steel wheel 1-1 and the second steel wheel 1-2; optionally, in this embodiment, the first steel wheel 1-1 is provided with an entry and exit position for the roller 1-5, and a roller stopper is provided. After the roller 1-5 is installed, the roller stopper is placed at the entry and exit position of the roller and fixedly connected to the first steel wheel 1-1, and the connection here can be made by using mounting screws; this embodiment realizes axial and radial load-bearing and power transmission between the input steel wheel and the output steel wheel; compared with the traditional design, it reduces the number of structural parts, reduces the structural thickness, and reduces the weight of the bearing wall, so that the harmonic reducer is lighter and the structure is simpler; the diameter of the harmonic reducer of this structure is the diameter of the steel wheel, the structure is simple, and the purpose of small size of the harmonic reducer is achieved;The first steel wheel 1-1 and the second steel wheel 1-2 are connected by rollers 1-5. The first steel wheel 1-1 serves as the outer ring of the roller bearing, and the second steel wheel 1-2 serves as the inner ring of the roller bearing. Thus, the first steel wheel 1-1, the second steel wheel 1-2, and the rollers 1-5 form an integrated roller bearing and steel wheel structure. The first steel wheel 1-1 and the second steel wheel 1-2 are connected to form an input steel wheel or an output steel wheel.

[0040] When the first steel wheel 1-1 is fixed, the power is output through the second steel wheel 1-2 in cooperation with the roller 1-5; when the second steel wheel 1-2 is fixed, the power is output through the first steel wheel 1-1 in cooperation with the roller 1-5. The materials of the first and second steel wheels 1-1, 1-2 are not limited here, and they can be made of metal materials, and further, they can be made of self-lubricating materials. In this embodiment, the first and second steel wheels 1-1, 1-2 can be optionally provided with threaded holes uniformly machined on their end faces and outer rings along the circumference, which serve as mounting holes for the input and output steel wheels. End-face mounting or radial mounting can be selected according to actual use requirements. In actual use, standard screws are used to achieve fixed installation of the harmonic reducer.

[0041] The specific structure of the flexible wheel 2 is not limited here. Optionally, the flexible wheel 2 can be a cylindrical structure, a bucket structure, etc. In this embodiment, optionally, the flexible wheel 2 is a cylindrical structure. The flexible wheel 2 adopts a cylindrical hollow structure to release the internal space to the greatest extent, providing operating space for internal wiring and installation; the material of the flexible wheel 3 is not limited here. Optionally, the flexible wheel 3 is made of metal material. The wall thickness of the flexible wheel is not limited here. It can be a structure with a whole thickness or a structure with one end thicker and the other end thinner. Optionally, in this embodiment, the flexible wheel 2 is a structure with uniform wall thickness. The structure with uniform wall thickness will not produce stress concentration. Under the same load conditions, the size of the harmonic reducer is reduced.

[0042] The inner circumferential wall of the steel wheel 1 is provided with steel wheel inner teeth 1-3, and the outer circumferential wall of the flexible wheel 2 is provided with flexible wheel outer teeth 2-1 meshing with the steel wheel inner teeth 1-3; the axial length relationship between the flexible wheel outer teeth 2-1 and the outer circumferential wall of the flexible wheel 2 is not limited here. Optionally, the length of the flexible wheel outer teeth 2-1 can be the same as the axial length of the outer circumferential wall of the flexible wheel 2, or the length of the flexible wheel transmission teeth can be less than the axial length of the outer circumferential wall of the flexible wheel. When the length of the flexible wheel outer teeth 2-1 is less than the axial length of the outer circumferential wall of the flexible wheel 2, it can be set at one end biased towards the flexible wheel, or at the center of the flexible wheel 2. Optionally, in this embodiment, the length of the flexible wheel outer teeth 2-1 is the same as the axial length of the outer circumferential wall of the flexible wheel 2.

[0043] The relationship between the inner teeth 1-3 of the steel wheel and the steel wheel 1 is not limited here. In this embodiment, the steel wheel 1 includes a first steel wheel 1-1 and a second steel wheel 1-2. The inner teeth 1-3 of the steel wheel can be set solely on the inner circumferential wall of the first steel wheel 1-1 or solely on the inner circumferential wall of the second steel wheel 1-2, or can be set on the inner circumferential walls of the first steel wheel 1-1 and the second steel wheel 1-2 at the same time. When the inner teeth 1-3 of the steel wheel are set solely on the inner circumferential wall of the first steel wheel 1-1 or the second steel wheel 1-2, the length of the inner teeth 1-3 of the steel wheel can be the same as the corresponding axial length of the steel wheel, or it can be less than the corresponding axial length of the steel wheel. At this time, the number of teeth of the outer teeth 2-1 of the flexible spline meshing with the inner teeth 1-3 of the steel wheel is not the same as the number of teeth of the inner teeth. Similarly, the harmonic reducer achieves the reduction ratio through the tooth difference between the external teeth 2-1 of the flexible spline and the internal teeth 1-3 of the steel wheel. The smaller the tooth difference, the greater the reduction ratio. The number of the internal teeth 1-3 of the steel wheel 1 is greater than the number of the external teeth 2-1 of the flexible spline. Because the wave generator 3 is an elliptical structure, the gear teeth between the major axis and the minor axis of the wave generator 3 are in a semi-meshing state of gradually entering engagement in different sections along the circumference of the flexible spline 2 and the steel wheel 1, which is called meshing in, and in a semi-meshing state of gradually exiting engagement, which is called meshing out. The wave generator 3 rotates continuously, so that the four movements of meshing in, meshing in, meshing out and disengaging continuously change their original working states. This movement is brought about by the tooth difference, that is, the flexible spline 2 and the steel wheel 1 form a staggered tooth movement.

[0044] When the inner teeth 1-3 of the steel wheel are simultaneously provided on the inner circumferential walls of the first steel wheel 1-1 and the second steel wheel 1-2, the inner teeth 1-3 of the steel wheel include the first inner teeth 1-3-1 and the second inner teeth 1-3-2 of the steel wheel. The inner circumferential wall of the first steel wheel 1-1 is provided with the first inner teeth 1-3-1, and the inner circumferential wall of the second steel wheel 1-2 is provided with the second inner teeth 1-3-2. When the number of teeth of the flexible spline external teeth 2-1 is fixed, the first steel wheel 1-1 is used as an input steel wheel or an output steel wheel by changing the gear ratio of the first inner teeth 1-3-1 and the second inner teeth 1-3-2. Steel wheel, correspondingly, the second steel wheel 1-2 serves as the output steel wheel or the input steel wheel. The relationship between the first steel wheel 1-1 and the first steel wheel inner teeth 1-3-1 is not limited here. Optionally, the length of the first steel wheel inner teeth 1-3-1 is the same as the axial length of the inner circumferential wall of the first steel wheel 1-1, or it can be less than the axial length of the inner circumferential wall of the first steel wheel 1-1. When the length of the first steel wheel inner teeth 1-3-1 is less than the axial length of the inner circumferential wall of the first steel wheel 1-1, it can be arranged at one end of the inner circumferential wall of the first steel wheel 1-1, or it can be arranged at the center position of the inner circumferential wall of the first steel wheel 1-1. The relationship between the second steel wheel 1-2 and the second steel wheel inner teeth 1-3-2 is not limited here. Optionally, the length of the second steel wheel inner teeth 1-3-2 is the same as the axial length of the inner circumferential wall of the second steel wheel 1-2, or it can be less than the axial length of the inner circumferential wall of the second steel wheel 1-2. When the length of the second steel wheel inner teeth 1-3-2 is less than the axial length of the inner circumferential wall of the second steel wheel 1-2, it can be arranged at one end of the inner circumferential wall of the second steel wheel 1-2, or it can be arranged at the center position of the inner circumferential wall of the second steel wheel 1-2. When the number of teeth of the flexible spline outer teeth 2-1 is fixed, optionally, the number of teeth of the first steel wheel inner teeth 1-3-1 can be greater than the number of teeth of the second steel wheel inner teeth 1-3-2, and the number of teeth of the second steel wheel inner teeth 1-3-2 can be the same as the number of teeth of the flexible spline outer teeth 2-1. Alternatively, the number of teeth of the first steel wheel inner teeth 1-3-1 can be less than the number of teeth of the second steel wheel inner teeth 1-3-2, and the number of teeth of the first steel wheel inner teeth 1-3-1 can be the same as the number of teeth of the flexible spline outer teeth 2-1. When the inner teeth part with the same number of teeth as the flexible spline outer teeth 2-1 can fix the flexible spline to prevent the flexible spline from moving during movement.

[0045] The specific structure of the flexible spline outer teeth 2-1 and the steel wheel inner teeth 1-3 is not limited here. Optionally, both are involute gears or circular arc gears; further, optionally, the contact heights of the flexible spline outer teeth 2-1 and the steel wheel inner teeth 1-3 are the same.

[0046] The wave generator 3 includes a cam 3-1 and a flexible bearing 3-2, and the flexible bearing is arranged between the flexible wheel and the cam; the flexible bearing 3-2 is arranged in the annular receiving cavity of the flexible wheel 2, and the cam 3-1 is arranged in the annular receiving cavity of the flexible bearing 3-2. The specific spacing between the flexible wheel 2, the flexible bearing 3-2 and the cam 3-1 is not limited here. Optionally, in this embodiment, the flexible wheel 2, the flexible bearing 3-2 and the cam 3-1 are tightly fitted, and the materials of the cam 3-1 and the flexible bearing 3-2 are not limited here. Optionally, the cam 3-1 and the flexible bearing 3-2 are made of metal materials, and the wall thickness of the cam 3-1 is not limited here. In this embodiment, the cam 3-1 is an annular structure processed from metal material, and the outer wall is an elliptical structure. When external power is input, the power is converted into deformation of the flexible bearing 3-2, and the flexible wheel 2 is deformed accordingly, thereby realizing power transmission. The flexible bearing 3-2 consists of a flexible bearing inner ring, a flexible bearing outer ring and a flexible bearing ball roller. Driven by the cam 3-1, the flexible bearing inner ring is deformed, and then the flexible bearing outer ring is deformed through the flexible bearing ball roller, and finally the flexible wheel 2 connected to the flexible bearing outer ring is deformed to realize power transmission.

[0047] The outer peripheral wall of at least one side of the cam 3-1 is provided with a bearing outer ring 3-3. The cam 3-1 is rotatably connected to the bearing outer ring 3-3. The outer peripheral wall of the bearing outer ring 3-3 is connected to the inner peripheral wall of the steel wheel 1. One end of the flexible wheel 2 and one end of the flexible bearing 3-2 abut against the bearing outer ring 3-3. The specific content of the abutment is not limited here. Optionally, the abutment can be direct abutment with the bearing outer ring 3-3 or indirect abutment through a component such as a gasket. The specific content of the rotatable connection between the cam 3-1 and the bearing outer ring 3-3 is also not limited here. Optionally, the rotation between the two can also be achieved through ball bearings, gears, etc. The bearing generally includes a bearing outer ring 3-3 and a bearing inner ring. The bearing outer ring 3-3 is arranged on the outer peripheral wall of the cam 3-1, which means that the cam 3-1 is used as the bearing inner ring, reducing one bearing inner ring and reducing the overall weight of the transmission system composed of the motor, bearings and harmonic reducer. When the bearing inner ring is not reduced, the overall volume of the harmonic reducer may become larger. The volume increase here may be radial or axial, which is not conducive to miniaturization. Therefore, the cam 3-1 is also used as the bearing inner ring, which is easy to achieve overall miniaturization of the overall transmission system and can also reduce the weight of the overall transmission system.

[0048] The connection method between the outer peripheral wall of the bearing outer ring 3-3 and the inner peripheral wall of the steel wheel 1 is not limited here. Optionally, it can be clamped, screwed, welded, or the bearing outer ring 3-3 and the steel wheel 1 are integrally formed. In this embodiment, the outer peripheral wall of the bearing outer ring 3-3 and the inner peripheral wall of one end of the steel wheel 1 are optionally connected by threads; the radial length relationship between the bearing outer ring 3-3 and the cam 3-1 is not limited here, nor is it limited whether the end face of the bearing outer ring 3-3 away from the flexible wheel 2 is flush with the end face on the same side of the cam 3-1 or the steel wheel 1. Optionally, this In the embodiment, the end face of the bearing outer ring 3-3 away from the flexible wheel 2 is flush with the end face on the same side of the cam 3-1 or the steel wheel 1. This arrangement can reduce the axial size of one bearing when the motor is connected to the harmonic reducer. Under the same load-bearing capacity, the power of the motor will not be reduced, thereby achieving the purpose of overall miniaturization. At the same time, one end of the flexible wheel 2 and one end of the flexible bearing 3-2 are in contact with the bearing outer ring 3-3, which can achieve the purpose of limiting the flexible wheel and the flexible bearing, and can omit the use of a sealing ring, simplifying the process and reducing costs.

[0049] In one embodiment of the present invention, further, as shown in FIG5 , a bearing outer ring 3-3 is also provided at the other end of the cam 3-1, and the outer peripheral wall of the bearing outer ring 3-3 is connected to the inner peripheral wall of the steel wheel 1, and the other end of the flexible wheel 2 and the other end of the flexible bearing 3-2 are in contact with the bearing outer ring 3-3. Optionally, the bearing outer rings 3-3 at both ends of the cam 3-1 can be structures of the same size or structures of different sizes. Optionally, in this embodiment, the axial dimensions of the bearing outer rings 3-3 at both ends are the same, which can facilitate mold making and simplify the process. The connection method of the outer peripheral wall of the bearing outer ring 3-3 at the other end and the inner peripheral wall of the steel wheel 1 is not limited here. Optionally, it can be snap-fitted, screwed, welded, or the bearing outer ring 3-3 at the other end can be integrally formed with the steel wheel 1. Here, when bearing outer rings 3-3 are provided at both ends of the cam 3-1, only the bearing outer ring 3-3 at one end can be integrally formed with the steel wheel 1. When both ends are integrally formed, the installation of the harmonic reducer cannot be completed. In this embodiment, optional The outer ring of the bearing outer ring 3-3 at the other end is connected to the inner ring of one end of the steel wheel 1 by a threaded connection. The radial length relationship between the bearing outer ring 3-3 and the cam 3-1 is not limited here, nor is it limited whether the end face of the bearing outer ring 3-3 at the other end away from the flexible wheel 2 is flush with the end face on the same side of the cam 3-1 or the steel wheel 1. Optionally, in this embodiment, the end face of the bearing outer ring 3-3 at the other end away from the flexible wheel 2 is flush with the end face on the same side of the cam 3-1 or the steel wheel 1. The ends of the flexible wheel 2 and the flexible bearing 3-2 are respectively abutted against the two bearing outer rings 3-3, achieving the purpose of limiting the ends of the flexible wheel and the flexible bearing, and also serving as a seal, which can omit the use of sealing rings on both sides, reducing costs. It can also reduce the axial length of the flange and screws required to connect the flexible wheel and the steel wheel in the harmonic reducer, achieving the purpose of further miniaturization under the same load capacity without reducing the power of the motor, and also reducing the weight of the harmonic reducer.

[0050] In one embodiment of the present invention, at least two flexible bearings 3-2 are further provided between the bearing outer rings 3-3 at both ends. The flexible bearings 3-2 are provided in the flexspline 2 to support the flexspline 2. In this embodiment, two flexible bearings 3-2 are optionally provided to fully support the flexspline, thereby reducing wear on the flexspline and extending its service life.

[0051] In one embodiment of the present invention, further, a ball 3-4 is provided between the cam 3-1 and the bearing outer ring 3-3, so that the cam and the bearing outer ring are rotatably connected through the ball 3-4, and the outer ring on one side of the cam 3-1 and the bearing outer ring is rollingly connected is provided with a cam annular groove 3-1-2, which is a mounting groove for the ball 3-4; the cam annular groove 3-1-2 can limit the ball 3-4, and can prevent the ball 3-4 and the bearing outer ring 3-3 from moving during movement. Further, optionally, a retainer is also included, and the retainer is provided between the cam boss 3-1-1 and the bearing outer ring 3-3. The retainer is evenly provided with multiple mounting positions with the ball 3-4, which can divide and limit the ball 3-4.

[0052] In one embodiment of the present invention, further, a cam boss 3-1-1 is provided on one side of the cam 3-1 which is rollingly connected to the bearing outer ring, and a cam annular groove 3-1-2 is provided on the outer ring of the cam boss 3-1-1. The specific relationship between the cam boss 3-1-1 and the bearing outer ring 3-3 is not limited here. The length of the cam boss 3-1-1 may be the same as the axial length of the bearing outer ring 3-3, or the length of the cam boss 3-1-1 may be greater than the axial length of the bearing outer ring 3-3, or the length of the cam boss 3-1-1 may be less than the axial length of the bearing outer ring 3-3. In this embodiment, optionally, the length of the cam boss 3-1-1 is the same as the axial length of the bearing outer ring 3-3, which can well support the bearing outer ring 3-3 and extend the service life of the harmonic reducer. The cam boss can limit the position of the bearing outer ring on the cam to prevent axial movement.

[0053] In one embodiment of the present invention, further, a bearing mounting position 1-4 is provided at the connection between the steel wheel 1 and the bearing outer ring 3-3. The specific structure of the bearing mounting position 1-4 is not limited here. Optionally, it can be a groove or a protrusion, regular or irregular, and can be a structure that matches the bearing outer ring 3-3 or a structure that does not match the bearing outer ring 3-3. Optionally, in this embodiment, the bearing mounting position 1-4 is set to an L-shaped annular groove structure that matches the bearing outer ring 3-3, such as a cam 3-1 with both ends provided. A bearing outer ring 3-3 is provided. It is not limited here whether the bearing mounting positions 1-4 at both ends have the same structure. Optionally, in this embodiment, the bearing mounting positions 1-4 have the same structure; the same structure is set at both ends to facilitate process design and production. The function of the bearing mounting positions 1-4 also includes limiting the bearing outer ring to prevent the bearing outer ring from moving during movement, and by utilizing the bearing mounting position part, a larger installation space can be left for the bearing outer ring, which facilitates the installation of the bearing outer ring and reduces the diameter of the harmonic reducer so that the diameter of the harmonic reducer is not affected by the bearing outer ring.

[0054] In one embodiment of the present invention, at least one end of the cam 3-1 is further extended, and the extended portion of the cam 3-1 is integrated with the motor shaft to form an integrated structure of the motor shaft and the cam 3-1, thereby further reducing the number of structural parts and the overall axial length of the harmonic reducer and the motor, reducing costs, and reducing the difficulty of coaxiality adjustment of multiple component connections.

[0055] This embodiment provides a bearing outer ring on the outer peripheral wall of at least one end of the cam, and uses the cam as the bearing inner ring, thereby reducing parts, and a bearing mounting position for the bearing outer ring is provided on the steel wheel, so that the bearing outer ring does not affect the radial size of the harmonic reducer, and the weight of the harmonic reducer is reduced under the same load-bearing capacity; when bearing outer rings are provided at both ends of the cam, the flexible wheel and the flexible bearing can be limited in many places, even between the two bearing outer rings, which can reduce the sealing ring and simplify the process. The flexible wheel adopts a cylindrical flexible wheel with uniform wall thickness, which not only does not generate stress points, but also prolongs the service life of the flexible wheel. The life of the harmonic reducer can be extended, and the hollow space of the harmonic reducer can be released to the maximum extent, providing the possibility for internal wiring; when the outer ring of the bearing is provided at both ends of the cam, the two flexible bearings can fully support the flexible wheel, further extending the service life of the flexible wheel; the outer ring of the bearing limits the flexible wheel, and there is no need to use additional connecting components and fixing components to fix the flexible wheel, further simplifying the process and reducing the volume and weight of the harmonic reducer; and the inner teeth of the steel wheel are divided into two parts, one part has the same number of teeth as the outer teeth of the flexible wheel, which plays the role of fixing the flexible wheel and preventing the flexible wheel from moving, and the other part has a different number of teeth from the outer teeth of the flexible wheel, which plays a transmission role. The harmonic reducer of this embodiment can be directly connected to the motor without the need for additional bearings, which reduces the axial length of the harmonic reducer when connected to the motor, and does not reduce the power of the motor, further achieving the purpose of miniaturization, reducing costs, and facilitating promotion.

[0056] Example 2

[0057] A robotic arm, FIG2 shows a schematic diagram of the robotic arm structure of an embodiment of the present invention; as shown in FIG2 , it includes one or more joints, and the joints include a harmonic reducer 4 as described in any one of the above embodiments.

[0058] Example 3

[0059] A robot, FIG3 shows a schematic structural diagram of a dual-arm robot according to an embodiment of the present invention; FIG4 shows a schematic structural diagram of a composite robot according to an embodiment of the present invention; as shown in FIG3 and FIG4, includes a robotic arm 5 as any one of the above embodiments.

[0060] In this embodiment, a harmonic reducer with integrated bearings is used, and the motor and the harmonic reducer are installed at the joints of the robot. The joints are smaller in size and lighter in weight. Under the same load-bearing capacity, the power of the motor will not be reduced, thereby achieving the purpose of miniaturization of the robot joints.

[0061] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

[0062] While the above description does not provide detailed technical details regarding patterning and etching of each layer, those skilled in the art will appreciate that various conventional methods can be used to form layers, regions, and the like in desired shapes. Furthermore, those skilled in the art may devise methods that differ from those described above to achieve the same structure.

Claims

1. A harmonic reducer, characterized in that: include: A steel wheel (1), a flexible wheel (2) and a wave generator (3); The steel wheel (1), the flexible wheel (2) and the wave generator (3) are all annular structures, and the steel wheel (1), the flexible wheel (2) and the wave generator (3) are assembled in sequence from the outside to the inside; The inner peripheral wall of the steel wheel (1) is provided with steel wheel internal teeth (1-3), and the outer peripheral wall of the flexible wheel (2) is provided with flexible wheel external teeth (2-1) meshing with the steel wheel internal teeth (1-3); The wave generator (3) comprises a cam (3-1) and a flexible bearing (3-2), wherein the flexible bearing is arranged between the flexible wheel and the cam; A bearing outer ring (3-3) is provided on the outer peripheral wall of at least one side of the cam (3-1); the cam (3-1) is rotatably connected to the bearing outer ring (3-3); the outer peripheral wall of the bearing outer ring (3-3) is connected to the inner peripheral wall of the steel wheel (1); one end of the flexible wheel (2) and one end of the flexible bearing (3-2) are in contact with the bearing outer ring (3-3).

2. The harmonic reducer according to claim 1, characterized in that: A ball (3-4) is arranged between the cam (3-1) and the bearing outer ring (3-3), so that the cam (3-1) and the bearing outer ring (3-3) are rotatably connected via the ball (3-4).

3. The harmonic reducer according to claim 2, characterized in that: The outer ring of one side of the cam (3-1) that is rollingly connected to the bearing outer ring (3-3) is provided with a cam annular groove (3-1-2) which is a mounting groove for the ball (3-4).

4. The harmonic reducer according to claim 1, characterized in that: A bearing mounting position (1-4) is provided at the connection between the steel wheel (1) and the bearing outer ring (3-3).

5. The harmonic reducer according to claim 1, characterized in that: The wave generator (3) comprises at least two flexible bearings (3-2).

6. The harmonic reducer according to claim 1, characterized in that: The steel wheel (1) is provided with threaded holes on the end surface and the outer ring.

7. The harmonic reducer according to claim 1, characterized in that: The steel wheel (1) comprises a first steel wheel (1-1) and a second steel wheel (1-2); the steel wheel internal teeth (1-3) comprise first steel wheel internal teeth (1-3-1) and second steel wheel internal teeth (1-3-2); the first steel wheel (1-1) is provided with the first steel wheel internal teeth (1-3-1) on its inner circumferential wall, and the second steel wheel (1-2) is provided with the second steel wheel internal teeth (1-3-2) on its inner circumferential wall; when the number of teeth of the flexible wheel external teeth is fixed, by changing the tooth number ratio of the first steel wheel internal teeth (1-3-1) and the second steel wheel internal teeth (1-3-2), the first steel wheel (1-1) is used as an input steel wheel or an output steel wheel, and correspondingly, the second steel wheel (1-2) is used as an output steel wheel or an input steel wheel.

8. The harmonic reducer according to claim 7, characterized in that: One end of the first steel wheel (1-1) is provided with a ring-shaped extending steel wheel boss (1-1-1), and the outer peripheral wall of the steel wheel boss (1-1-1) is provided with a first V-shaped annular groove; the inner ring of the second steel wheel (1-2) is provided with a first steel wheel part (1-2-1) and a second steel wheel part (1-2-2), and the inner diameter of the first steel wheel part (1-2-1) is larger than the inner diameter of the second steel wheel part (1-2-2); the inner peripheral wall of the first steel wheel part (1-2-1) of the second steel wheel (1-2) is provided with a second V-shaped annular groove, which cooperates with the first V-shaped annular groove to form a rectangular annular groove; and also includes a roller (1-5), and the roller (1-5) is arranged in the rectangular annular groove.

9. A robotic arm, characterized in that: It comprises one or more joints, wherein the joints include a harmonic reducer (4) according to any one of claims 1 to 8.

10. A robot, characterized in that: Comprising a robotic arm (5) as claimed in claim 9.

Images