Wave generator, harmonic reducer and industrial robot

Abstract

The invention discloses a wave generator, a harmonic reducer and an industrial robot, and relates to the field of harmonic reducers. The wave generator comprises a cam, an outer ring, a retainer and a plurality of rolling bodies, the rolling bodies are arranged between a first roller path of an annular part and a second roller path of the outer ring, the positions of the rolling bodies are limited through the retainer, and friction force generated when the cam rotates can be reduced. The cam comprises the annular part fixedly connected to the base part, and the first raceway is machined after the annular part is fixed to the base part, so that the problem that the first raceway is distorted due to the fact that the base part and the annular part need to be in interference fit is solved, the geometric accuracy and the form and position accuracy of the first raceway are guaranteed, and the operation stability of the wave generator is improved. And meanwhile, the problem that the annular part is easy to break and lose efficacy under the repeated action of alternating bending stress can be solved, so that the strength of the annular part is improved, and the service life of the wave generator is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of harmonic reducers, and in particular to a wave generator, a harmonic reducer and an industrial robot. Background Art

[0002] The wave generator of the harmonic reducer includes a cam and a flexible bearing. The interference fit between the cam and the inner ring of the flexible bearing can easily lead to distortion of the raceway of the inner ring, reduce the geometric accuracy and position accuracy, and affect the stability of the flexible bearing. When the harmonic reducer is working, the inner ring of the flexible bearing may break and fail under the repeated action of alternating bending stress. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a wave generator, which can improve the problem of raceway distortion and fracture failure caused by interference fitting by fixedly connecting a cam and an inner ring of a flexible bearing.

[0004] The present invention also provides a harmonic reducer having the wave generator and an industrial robot using the harmonic reducer.

[0005] The wave generator according to the first aspect of the present invention comprises:

[0006] A cam, comprising a base and an annular portion, wherein the annular portion is arranged around the base and fixedly connected to the base, and an outer peripheral wall of the annular portion is provided with a first raceway, and a surface hardness of the first raceway is greater than a surface hardness of the base;

[0007] An outer ring is arranged around the cam, and a second raceway is arranged on a side of the outer ring facing the first raceway;

[0008] A retainer, disposed between the annular portion and the outer ring;

[0009] A plurality of rolling bodies are mounted on the retaining frame and movably connected between the first raceway and the second raceway.

[0010] The wave generator according to the embodiment of the present invention has at least the following beneficial effects:

[0011] By arranging a plurality of rolling bodies between the first raceway of the annular part and the second raceway of the outer ring, and limiting the position of the rolling bodies by a retaining frame, the friction force when the cam rotates can be reduced. Since the cam includes an annular part fixedly connected to the base, and the first raceway is processed after the annular part is fixed to the base, there is no problem of distortion of the first raceway caused by interference fit between the base and the annular part, thereby ensuring the geometric accuracy and shape and position accuracy of the first raceway and improving the stability of the wave generator. At the same time, it can improve the problem of fracture and failure of the annular part caused by repeated action of alternating bending stress, thereby improving the strength of the annular part and improving the service life of the wave generator. The surface hardness of the first raceway is greater than the surface hardness of the base, which can improve the load-bearing capacity and wear resistance of the first raceway, thereby improving the service life and performance of the first raceway.

[0012] According to some embodiments of the present invention, the annular portion is formed on the base portion, and the material hardness of the annular portion is greater than the material hardness of the base portion.

[0013] According to some embodiments of the present invention, the annular portion and the base are integrally formed parts made of the same material, a hardness layer is formed on the surface of the first raceway, the hardness layer is formed by a heat treatment process, and the hardness of the hardness layer is greater than the surface hardness of the base.

[0014] According to some embodiments of the present invention, the annular portion and the base are integrally formed parts made of the same material, a hardness layer is formed on the surface of the first raceway, the hardness layer is formed by embedding metal, and the hardness of the hardness layer is greater than the surface hardness of the base.

[0015] According to some embodiments of the present invention, along the radial direction of the cam, the maximum depth of the first raceway is smaller than the thickness of the annular portion.

[0016] According to some embodiments of the present invention, the maximum depth of the first raceway is H1, and the thickness of the annular portion is H2, satisfying H2-H1≥1 mm.

[0017] According to some embodiments of the present invention, the hardness of the first raceway is X, satisfying: 56HRC≤X≤68HRC; and / or the hardness of the second raceway is Y, satisfying: 56HRC≤Y≤68HRC.

[0018] According to some embodiments of the present invention, the base is made of one of ductile iron and alloy steel; and / or the annular portion is made of one of bearing steel and alloy steel.

[0019] A harmonic reducer according to an embodiment of the second aspect of the present invention comprises the wave generator described in the above embodiment.

[0020] The harmonic reducer according to the embodiment of the present invention has at least the following beneficial effects:

[0021] By arranging a plurality of rolling bodies between the first raceway of the annular part and the second raceway of the outer ring, and limiting the position of the rolling bodies by a retaining frame, the friction force when the cam rotates can be reduced. Since the cam includes an annular part fixedly connected to the base, and the first raceway is processed after the annular part is fixed to the base, there is no problem of distortion of the first raceway caused by interference fit between the base and the annular part, thereby ensuring the geometric accuracy and shape and position accuracy of the first raceway and improving the stability of the wave generator. At the same time, it can improve the problem of fracture and failure of the annular part caused by repeated action of alternating bending stress, thereby improving the strength of the annular part and improving the service life of the wave generator. The surface hardness of the first raceway is greater than the surface hardness of the base, which can improve the load-bearing capacity and wear resistance of the first raceway, thereby improving the service life and performance of the first raceway.

[0022] An industrial robot according to an embodiment of the third aspect of the present invention comprises the harmonic reducer described in the embodiment of the second aspect.

[0023] The industrial robot according to the embodiment of the present invention has at least the following beneficial effects:

[0024] By adopting the harmonic reducer of the embodiment of the second aspect of the present invention, the harmonic reducer is arranged at the rotating joint of the industrial robot, and the input speed is reduced and transmitted to the output shaft, so as to realize the precise position and speed control of the joint of the industrial robot. The harmonic reducer can convert the high-speed and low-torque motor output into a low-speed and high-torque output to meet the movement requirements of the robot. The harmonic reducer has a compact structure and a small size, and can achieve high torque output while maintaining a small weight, so that the industrial robot can move smoothly, reduce the maintenance frequency of the industrial robot, reduce the use cost, and improve the reliability of the industrial robot.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 is a structural schematic diagram of a harmonic reducer according to an embodiment of the present invention;

[0028] Figure 2 is an exploded view of a harmonic reducer according to an embodiment of the present invention;

[0029] Figure 3 A wave generator according to an embodiment of the present invention;

[0030] Figure 4 yes Figure 3 Sectional view at AA in the middle;

[0031] Figure 5 yes Figure 3 A cross-sectional view of the rolling element hidden in the wave generator;

[0032] Figure 6 It is a schematic structural diagram of a wave generator according to another embodiment of the present invention.

[0033] Reference numerals:

[0034] Harmonic reducer 1000;

[0035] Wave generator 100; cam 110; base 111; annular portion 112; first raceway 113; outer ring 120; second raceway 121; rolling element 130; cage 140;

[0036] Ganglun 200;

[0037] Flexspline 300. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0042] A harmonic gear reducer is a reducer composed of a fixed internal gear rigid wheel, a flexible wheel, and a wave generator that causes radial deformation of the flexible wheel. The flexible wheel is sleeved on the outside of the wave generator, and the rigid wheel is sleeved on the outside of the flexible wheel. The wave generator drives the flexible wheel to deform radially and rotate, causing the flexible wheel to produce elastic deformation, and transmits power and motion through the relative staggered teeth between the rigid wheel and the flexible wheel. Due to the inherent characteristics of the harmonic reducer, the meshing area of ​​the flexible wheel and the rigid wheel is large, which makes its load-bearing capacity relatively high, making the harmonic reducer widely used in electronics, aerospace, industrial robots and other fields. The application scenarios of harmonic reducers tend to be small equipment. At present, harmonic reducers are developing towards high speed, high rigidity, and long life. The wave generator includes a cam and a flexible bearing. The interference fit of the cam and the inner ring of the flexible bearing can easily cause the raceway of the inner ring to be distorted, and the geometric accuracy and shape and position accuracy are reduced, affecting the stability of the flexible bearing. And when the harmonic reducer is working, the inner ring of the flexible bearing may break and fail under the repeated action of alternating bending stress.

[0043] Based on this, the present invention provides a wave generator, which can improve the problems of distortion of the raceway of the inner ring and easy fracture and failure of the inner ring by making the cam and the inner ring of the flexible bearing into an integrated structure.

[0044] The following is a description with reference to the accompanying drawings:

[0045] Reference Figure 1 and Figure 2 As shown, a wave generator 100 according to an embodiment of the present invention is used in a harmonic reducer 1000. Figure 3 , Figure 4 and Figure 5 As shown, the wave generator 100 of the embodiment of the present invention includes a cam 110, an outer ring 120, a retainer 140 and a plurality of rolling elements 130. The cam 110 includes a base 111 and an annular portion 112. The annular portion 112 is arranged around the base 111 and fixedly connected to the base 111. The outer peripheral wall of the annular portion 112 is provided with a first raceway 113. The first raceway 113 is arranged around the annular portion 112, and the surface hardness of the first raceway 113 is greater than the hardness of the base 111. The outer ring 120 surrounds the cam 110 and is arranged at intervals. The outer ring 120 is provided with a second raceway 121 on the side facing the first raceway 113. The retainer 140 is arranged between the annular portion 112 and the outer ring 120. The plurality of rolling elements 130 are mounted on the retainer 140 and are movably connected to the first raceway 113 and the second raceway 121. The cage 140 serves to separate adjacent rolling elements 130, preventing adjacent rolling elements 130 from contacting each other, thereby ensuring that the rolling elements 130 move along a predetermined position. The rolling elements 130 serve to reduce the friction between the outer ring 120 and the annular portion 112, effectively reducing the wear of the raceway, and increasing the service life of the wave generator 100.

[0046] It is understandable that, since the cam 110 includes an annular portion 112 fixedly connected to the base 111, and the first raceway 113 is processed after the annular portion 112 is fixed to the base 111, there is no problem of distortion of the first raceway 113 caused by the interference fit between the base 111 and the annular portion 112, thereby ensuring the geometric accuracy and shape and position accuracy of the first raceway 113 and improving the stability of the operation of the wave generator 100. At the same time, it can improve the problem that the annular portion 112 is prone to fracture and failure under the repeated action of alternating bending stress, thereby improving the strength of the annular portion 112 and improving the service life of the wave generator 100. The surface hardness of the first raceway 113 is greater than the hardness of the base 111, which can improve the load-bearing capacity and wear resistance of the first raceway 113, thereby improving the service life and performance of the first raceway 113.

[0047] It should be noted that in order to make the surface hardness of the first raceway 113 greater than the surface hardness of the base 111, it can be achieved in a variety of ways, for example, through the following three embodiments:

[0048] In the first embodiment of the present invention, the annular portion 112 is formed on the base 111, and the material hardness of the annular portion 112 is greater than the material hardness of the base 111. For example, the annular portion 112 and the base 111 are made of different materials to obtain different hardnesses. When the annular portion 112 and the base 111 are made of different materials, for example, the base 111 is made of ductile iron and the annular portion 112 is made of bearing steel; or the base 111 is made of ductile iron and the annular portion 112 is made of alloy steel; or the base 111 is made of alloy steel and the annular portion 112 is made of bearing steel. Two different materials are integrally formed by casting. The base 111 can be cast first, and then a metal solution of another material is poured on the outer peripheral wall of the base 111 to form the annular portion 112, thereby casting a blank of the cam 110, which is then processed later. Other methods may include stacking, powder metallurgy, centrifugal casting and other process methods. By controlling the conditions of the molding process, the strength of the two different materials at the connection point can be adjusted to ensure that the two materials will not separate, thereby improving the stability of the connection.

[0049] Among them, ductile iron has high tensile strength, good toughness, strong wear resistance, impact resistance, low cost, etc., and is not prone to fracture, fatigue, brittle failure and other problems. Bearing steel has the advantages of high hardness, high strength and wear resistance, adapts to high temperature and high speed working conditions, and has good fatigue resistance and thermal deformation resistance. Alloy steel has high strength, good heat treatment performance and corrosion resistance. It can work under various temperature and stress conditions and has a high life and durability. Therefore, according to the actual situation, the appropriate materials are selected for combination, and the materials used are reasonably planned to reduce the production cost while meeting the performance requirements of the wave generator 100.

[0050] Reference Figure 6 As shown, in the second embodiment of the present invention, the annular portion 112 and the base portion 111 are integrally formed parts made of the same material, and a hardness layer is formed on the surface of the first raceway 113, and the hardness layer is formed by adopting different heat treatment methods. For example, the annular portion 112 and the base portion 111 are both made of alloy steel, and the hardness of the first raceway 113 can be improved by high-frequency heat treatment on the first raceway 113. For example, by heating the surface of the first raceway 113 to above the critical temperature and then rapidly cooling it, the surface structure of the first raceway 113 can be made denser, so that the first raceway 113 forms a hardness layer. Increasing the hardness of the first raceway 113 can enhance the resistance of the first raceway 113 to load and wear. High-frequency heat treatment can also improve the fatigue resistance of the first raceway 113. By adjusting the heat treatment parameters, internal stress can be eliminated, and the tensile strength and deformation resistance of the material can be improved, thereby extending the service life of the first raceway 113, making it have higher strength, toughness and wear resistance, and improving the overall performance. The first raceway 113 is processed after the annular portion 112 is fixed to the base 111. Therefore, there is no problem of distortion of the first raceway 113 caused by interference fit between the base 111 and the annular portion 112. The geometric accuracy and shape and position accuracy of the first raceway 113 are guaranteed, and the stability of the operation of the wave generator 100 is improved.

[0051] In other embodiments, in addition to high-frequency heat treatment, carbonitriding, tempering and the like can also be used. Compared with the high-frequency heat treatment method and the carbonitriding method, the first raceway 113 is processed after carbonitriding, and it is difficult to process after hardening. If the first raceway 113 is processed and then carbonitriding is performed, deformation is easily caused due to the irregularity of the raceway. The high-frequency heat treatment only strengthens the surface of the annular portion 112 to a certain depth, and the internal structure and performance of the annular portion 112 are basically maintained before the treatment. Because it is local heating, it can significantly reduce the deformation caused by quenching and reduce energy consumption.

[0052] Reference Figure 6 As shown, when the annular portion 112 and the base 111 are an integrally molded part made of the same material, in order to improve the hardness of the first raceway 113, in the third embodiment of the present invention, a metal with higher hardness can be embedded in the first raceway 113 to form a hardness layer, thereby improving the hardness of the first raceway 113. The appropriate method is selected according to the actual situation.

[0053] Reference Figure 5As shown, in the embodiment of the present invention, along the radial direction of the cam 110, the maximum depth of the first raceway 113 is less than the thickness of the annular portion 112, that is, the first raceway 113 is completely arranged on the annular portion 112 and cannot exceed the thickness of the annular portion 112. For example, the maximum depth of the first raceway 113 is H1, and the thickness of the annular portion 112 is H2, satisfying: H2-H1≥1mm. For example, the difference between H2 and H1 can be 1.5mm, 2mm, 2.5mm, 3mm, etc. It can ensure that the materials constituting the first raceway 113 are consistent, so as to avoid the situation where the performance of different parts of the first raceway 113 is different due to the inconsistency of the two materials. Assuming that the maximum depth of the first raceway 113 exceeds the thickness of the annular portion 112, the performance of each part of the first raceway 113 is different due to the inconsistency of the materials constituting the first raceway 113. When the rolling element 130 runs on the first raceway 113, it is easy for the first raceway 113 to have greater wear at the connection between the two materials, thereby reducing the strength and wear resistance of the first raceway 113 and also reducing the service life. Therefore, the maximum depth of the first raceway 113 is less than the thickness of the annular portion 112, so that the materials constituting the first raceway 113 are consistent, which can improve the wear resistance and service life of the first raceway 113.

[0054] In an embodiment of the present invention, the hardness of the first raceway 113 is X, satisfying: 56HRC≤X≤68HRC; the hardness of the second raceway 121 is Y, satisfying: 56HRC≤Y≤68HRC. It should be noted that Rockwell hardness is an indicator for determining the hardness value based on the depth of plastic deformation of the indentation, with 0.002 mm as a hardness unit. Using different indenters and different test forces in the Rockwell hardness test will produce different combinations, corresponding to different scales of Rockwell hardness. There are three commonly used scales, and their applications cover almost all commonly used metal materials. HRA is the hardness obtained by using a 60Kg load and a diamond cone indenter, and is used for materials with higher hardness. For example, steel sheets and cemented carbides. HRB is the hardness obtained by using a 100Kg load and a hardened steel ball with a diameter of 1.5875mm, and is used for materials with lower hardness. For example, mild steel, non-ferrous metals, annealed steel, etc. HRC is the hardness obtained by using a 150Kg load and a diamond cone indenter, and is used for materials with higher hardness. For example, hardened steel, cast iron, etc.

[0055] It is understandable that, assuming that the hardness of the first raceway 113 is less than 56HRC, the strength of the first raceway 113 is insufficient, which is easy to aggravate wear and reduce the life of the first raceway 113. Assuming that the hardness of the first raceway 113 is greater than 68HRC, it is difficult to process, the cost is high, and the brittleness increases, and the impact resistance decreases. Therefore, a reasonable design of the hardness of the first raceway 113 can improve the strength of the first raceway 113 while controlling the cost within a reasonable range. Assuming that the hardness of the second raceway 121 is less than 56HRC, it is easy to cause the strength of the second raceway 121 to be insufficient, aggravate wear, and reduce the life of the second raceway 121. Assuming that the hardness of the second raceway 121 is greater than 68HRC, it is difficult to process, the cost is high, and the brittleness increases, and the impact resistance decreases. Therefore, a reasonable design of the hardness of the second raceway 121 can improve the strength of the second raceway 121 while controlling the cost within a reasonable range.

[0056] In an embodiment of the present invention, the rolling element 130 may be a ball, and the circular rolling contact of the ball is on the first raceway 113 and the second raceway 121, bearing and transmitting axial and radial loads. The spherical shape of the ball can make the wave generator 100 evenly distributed in multiple directions, so that the wave generator 100 has a higher load-bearing capacity. At the same time, the rolling contact between the ball and the first raceway 113 and the second raceway 121 can reduce friction, and has lower energy loss than sliding friction. The use of rolling friction can reduce heat generation, reduce energy loss, and improve the working efficiency and running stability of the wave generator 100. And due to the characteristics of rolling contact, the use of balls as rolling elements 130 can reduce vibration and noise compared to other types of rolling elements 130. The gap between the ball and the raceway can reduce impact and vibration, making the operation of the wave generator 100 more stable, thereby reducing noise generation. In another embodiment of the present invention, the rolling element 130 can also be a roller, and a suitable rolling element 130 is selected according to actual conditions, and the present invention is no longer specifically limited here.

[0057] A harmonic reducer 1000 according to an embodiment of the present invention includes the wave generator 100 of the above embodiment. The harmonic reducer 1000 also includes a rigid wheel 200 and a flexible wheel 300. The outer ring 120 of the wave generator 100 and the inner wall of the flexible wheel 300 are clearance-matched, and the outer teeth of the flexible wheel 300 are meshed with the inner teeth of the rigid wheel 200. When the cam 110 rotates, the flexible wheel 300 can repeatedly deform so that the outer teeth are meshed with different inner teeth, thereby driving the flexible wheel 300 and the rigid wheel 200 to move relative to each other.

[0058] The harmonic reducer 1000 of the embodiment of the present invention adopts the wave generator 100 of the above embodiment, and by arranging a plurality of rolling elements 130 between the first raceway 113 of the annular portion 112 and the second raceway 121 of the outer ring 120, and limiting the position of the rolling elements 130 by the retainer 140, the friction force when the cam 110 rotates can be reduced. Since the cam 110 includes an annular portion 112 fixedly connected to the base 111, and the first raceway 113 is processed after the annular portion 112 is fixed to the base 111, there is no problem of distortion of the first raceway 113 caused by interference fitting between the base 111 and the annular portion 112, the geometric accuracy and shape and position accuracy of the first raceway 113 are guaranteed, and the stability of the operation of the wave generator 100 is improved. At the same time, the problem that the annular portion 112 is easily broken and failed under the repeated action of alternating bending stress can be improved, thereby improving the strength of the annular portion 112 and the service life of the wave generator 100. The surface hardness of the first raceway 113 is greater than the hardness of the base 111 , which can improve the load-bearing capacity and wear resistance of the first raceway 113 , thereby improving the service life and performance of the first raceway 113 .

[0059] Since the harmonic reducer 1000 adopts all the technical solutions of the wave generator 100 of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be repeated here.

[0060] An industrial robot according to an embodiment of the present invention includes the harmonic reducer 1000 of the above embodiment. The industrial robot may be a handling robot, a welding robot, an assembly robot, a processing robot, a spraying robot, a cleaning robot, a collaborative robot, etc. The harmonic reducer 1000 is usually arranged at the rotating joint of the industrial robot. The harmonic reducer 1000 achieves precise position and speed control of the joint of the industrial robot by reducing the input speed and transmitting it to the output shaft. The harmonic reducer 1000 can convert the output of the motor with high speed and low torque into the output with low speed and high torque to meet the motion requirements of the robot. The harmonic reducer 1000 also has extremely high transmission accuracy and repeatability, and can generally achieve precise motion control. The positioning and motion accuracy of the industrial robot are very important, especially in applications requiring high precision, such as assembly, welding, precision machining, etc. Compared with other transmission devices, the harmonic reducer 1000 has a compact structure and a small size, and can achieve high torque output while maintaining a small weight. This is particularly important for industrial robots, allowing industrial robots to achieve highly flexible movement in a limited space.

[0061] The industrial robot of the embodiment of the present invention adopts the harmonic reducer 1000 of the above embodiment, and by arranging the plurality of rolling elements 130 of the wave generator 100 of the harmonic reducer 1000 between the first raceway 113 of the annular portion 112 and the second raceway 121 of the outer ring 120, and limiting the position of the rolling elements 130 by the retaining frame 140, the friction force when the cam 110 rotates can be reduced. Since the cam 110 includes an annular portion 112 fixedly connected to the base 111, and the first raceway 113 is processed after the annular portion 112 is fixed to the base 111, there is no problem of distortion of the first raceway 113 caused by interference fitting between the base 111 and the annular portion 112, the geometric accuracy and shape and position accuracy of the first raceway 113 are guaranteed, and the stability of the operation of the wave generator 100 is improved. At the same time, the problem that the annular portion 112 is easily broken and failed under the repeated action of alternating bending stress can be improved, thereby improving the strength of the annular portion 112 and improving the service life of the wave generator 100. The surface hardness of the first raceway 113 is greater than the hardness of the base 111 , which can improve the load-bearing capacity and wear resistance of the first raceway 113 , thereby improving the service life and performance of the first raceway 113 .

[0062] Since the industrial robot adopts all the technical solutions of the harmonic reducer 1000 of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment, which will not be repeated here.

[0063] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A wave generator, characterized in that include: A cam, comprising a base and an annular portion, wherein the annular portion is arranged around the base and fixedly connected to the base, and an outer peripheral wall of the annular portion is provided with a first raceway, and a surface hardness of the first raceway is greater than a surface hardness of the base; An outer ring is arranged around the cam, and a second raceway is arranged on a side of the outer ring facing the first raceway; A retainer, disposed between the annular portion and the outer ring; A plurality of rolling bodies are mounted on the retaining frame and movably connected between the first raceway and the second raceway.

2. The wave generator according to claim 1, characterized in that The annular portion is formed on the base portion, and the material hardness of the annular portion is greater than the material hardness of the base portion.

3. The wave generator according to claim 1, characterized in that The annular portion and the base portion are integrally formed parts made of the same material. A hardness layer is formed on the surface of the first raceway. The hardness layer is formed by a heat treatment process. The hardness of the hardness layer is greater than the surface hardness of the base portion.

4. The wave generator according to claim 1, characterized in that The annular portion and the base portion are integrally formed parts made of the same material. A hardness layer is formed on the surface of the first raceway. The hardness layer is formed by embedding metal. The hardness of the hardness layer is greater than the surface hardness of the base portion.

5. The wave generator according to claim 1, characterized in that In a radial direction of the cam, a maximum depth of the first raceway is smaller than a thickness of the annular portion.

6. The wave generator according to claim 5, characterized in that The maximum depth of the first raceway is H1, and the thickness of the annular portion is H2, satisfying H2-H1≥1 mm.

7. The wave generator according to claim 1, characterized in that The hardness of the first raceway is X, satisfying: 56HRC≤X≤68HRC; and / or the hardness of the second raceway is Y, satisfying: 56HRC≤Y≤68HRC.

8. The wave generator according to claim 1, characterized in that The base is made of ductile iron or alloy steel; and / or the annular portion is made of bearing steel or alloy steel.

9. Harmonic reducer, characterized in that: Comprising a wave generator as claimed in any one of claims 1 to 8.

10. An industrial robot, characterized in that Comprising a harmonic reducer as claimed in claim 9.

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