Cam, wave generator and harmonic reducer

Abstract

The present application provides a cam, a wave generator and a harmonic reducer. The outer contour line of the cam includes a first curve, a second curve, a third curve and a fourth curve connected in sequence. When the outer contour line is placed in a plane rectangular coordinate system, the center of the cam is point O. The first curve is located in the first quadrant. The second curve is symmetric with the first curve about the Y-axis. The third curve is symmetric with the second curve about the X-axis. The fourth curve is symmetric with the first curve about the X-axis. The first curve satisfies the equation: #imgabs0#; x is the abscissa and f(x) is the ordinate; p1-p 10 Each satisfies a certain value range. With such a setting, the problem of how to improve the performance of the harmonic reducer in terms of load capacity and service life in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the technical field of harmonic reducers, and in particular to a cam, a wave generator and a harmonic reducer. Background Art

[0002] The harmonic reducer is a gear transmission structure that relies on a wave generator equipped with a flexible bearing to make the flexible wheel produce controllable elastic deformation and mesh with the rigid wheel to transmit motion and power. The wave generator consists of a cam and a flexible bearing.

[0003] With the development of the industry, the requirements for harmonic reducers are gradually increasing. How to improve the performance of harmonic reducers in terms of load-bearing capacity and service life is still a direction that technical personnel in this field continue to study. Summary of the invention

[0004] In view of this, the present application provides a cam, a wave generator and a harmonic reducer to solve the problem in the prior art of how to improve the performance of the harmonic reducer in terms of load-bearing capacity and service life.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] A cam, wherein the outer contour line of the cam comprises a first curve, a second curve, a third curve and a fourth curve connected in sequence, the outer contour line is placed in a plane rectangular coordinate system, the center of the cam is point O, the first curve is located in a first quadrant, the second curve and the first curve are symmetrical about the Y axis, the third curve and the second curve are symmetrical about the X axis, the fourth curve and the first curve are symmetrical about the X axis, and the first curve satisfies the equation:

[0007] ; x is the horizontal coordinate, f(x) is the vertical coordinate;

[0008] p1 satisfies -9.267e-9≤p1≤-1.028e-7;

[0009] p2 satisfies 9.54e-8≤p2≤1.039e-6;

[0010] p3 satisfies -4.404e-6≤p3≤0.000411;

[0011] p4 satisfies -0.009594≤p4≤0.01013;

[0012] p5 satisfies -0.1367≤p5≤0.1313;

[0013] p6 satisfies -1.062≤p6≤1.093;

[0014] p7 satisfies -4.943≤p7≤4.852;

[0015] p8 satisfies -11.19≤p8≤11.26;

[0016] p9 satisfies -10.1≤p9≤10.05;

[0017] p 10 Satisfying 20.39≤p 10 ≤25.3.

[0018] Optional, p1 is -5.05e-9, p2 is 4.262e-7, p3 is -1.471e-5, p4 is 0.0002666, p5 is -0.002715, p6 is 0.01539, p7 is -0.04237, p8 is 0.0373, p9 is 0, p 10 The value is 22.85.

[0019] Optionally, a connection point between the first curve and the fourth curve, and a connection point between the second curve and the third curve are both set as transition curves, and a radius of the transition curve is R, 5mm≤R≤30mm.

[0020] Optionally, the value of R is 20 mm.

[0021] A wave generator comprises a flexible bearing and any one of the above cams, wherein the flexible bearing is sleeved on the cam.

[0022] A harmonic reducer comprises a rigid wheel, a flexible wheel and the above-mentioned wave generator.

[0023] The cam provided in the present application has an outer contour line including a first curve, a second curve, a third curve and a fourth curve connected in sequence. The outer contour line is placed in a plane rectangular coordinate system, the center of the cam is point O, the first curve is located in the first quadrant, the second curve and the first curve are symmetrical about the Y axis, the third curve and the second curve are symmetrical about the X axis, the fourth curve and the first curve are symmetrical about the X axis, and the first curve satisfies the equation:

[0024] ; x is the horizontal coordinate, f(x) is the vertical coordinate; p1 satisfies -9.267e-9≤p1≤-1.028e-7; p2 satisfies 9.54e-8≤p2≤1.039e-6; p3 satisfies -4.404e-6≤p3≤0.000411; p4 satisfies -0.009594≤p4≤0.01013; p5 satisfies -0.1367≤p5≤0.1313; p6 satisfies -1.062≤p6≤1.093; p7 satisfies -4.943≤p7≤4.852; p8 satisfies -11.19≤p8≤11.26; p9 satisfies -10.1≤p9≤10.05; p 10 Satisfying 20.39≤p 10 ≤25.3.

[0025] With such a setting, the applicant obtained the above-mentioned high-order polynomial equation after many explorations and data fitting, and used it as the design basis for the cam outer contour line. The cam designed and shaped according to the outer contour line was applied to the harmonic reducer after experiments and verification. It can effectively reduce the stress on the flexible wheel and the flexible bearing in the harmonic reducer, improve the use environment of the flexible wheel and the flexible bearing, and enhance the load-bearing capacity and service life of the harmonic reducer, so that the harmonic reducer has better performance, which solves the problem of how to improve the performance of the harmonic reducer in terms of load-bearing capacity and service life in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0027] Figure 1 A schematic diagram of the cam outer contour line provided in an embodiment of the present application.

[0028] Figure 2 A comparison diagram of the cam outer contour line provided in the embodiment of the present application and the cam outer contour line in the prior art.

[0029] Figure 3 for Figure 2 Detailed view in the first quadrant.

[0030] exist Figure 1-Figure 3 middle:

[0031] 1. The first curve; 2. The second curve; 3. The third curve; 4. The fourth curve. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] In the harmonic reducer in the related art, the flexible bearing is composed of a flexible bearing outer ring, a flexible bearing inner ring and balls, the flexible bearing and the cam form a wave generator, and the rigid wheel and the flexible wheel are tooth-meshed.

[0034] The applicant found that the cam, as a power component of the harmonic reducer, has a very important influence on the performance of the harmonic reducer in terms of its outer contour design and size parameters. The contour of a conventional cam is usually designed to be elliptical. The applicant found that the cam with an elliptical contour has a low contribution to improving the stress of the flexible wheel and the flexible bearing, improving the load-bearing capacity and service life of the harmonic reducer, and the cam itself still has a high design improvement space.

[0035] like Figure 1-Figure 3 As shown, an embodiment of the present application provides a cam, the outer contour line of the cam includes a first curve 1, a second curve 2, a third curve 3 and a fourth curve 4 connected in sequence, the outer contour line is placed in a plane rectangular coordinate system, the center of the cam is the coordinate origin (that is, point O in the figure), the first curve 1 is located in the first quadrant, the second curve 2 and the first curve 1 are symmetrical about the Y axis, the third curve 3 and the second curve 2 are symmetrical about the X axis, the fourth curve 4 and the first curve 1 are symmetrical about the X axis, and the first curve 1 satisfies the equation:

[0036] ; x is the horizontal coordinate, f(x) is the vertical coordinate; p1-p 10 Each of them satisfies a certain range of values. Specifically, p1 satisfies -9.267e-9≤p1≤-1.028e-7; p2 satisfies 9.54e-8≤p2≤1.039e-6; p3 satisfies -4.404e-6≤p3≤0.000411; p4 satisfies -0.009594≤p4≤0.01013; p5 satisfies -0.1367≤p5≤0.1313; p6 satisfies -1.062≤p6≤1.093; p7 satisfies -4.943≤p7≤4.852; p8 satisfies -11.19≤p8≤11.26; p9 satisfies -10.1≤p9≤10.05; p 10 Satisfying 20.39≤p 10 ≤25.3. It should be noted that the e in the equation represents the expression of exponent in scientific notation.

[0037] With such a setting, the applicant obtained the above-mentioned high-order polynomial equation after many explorations and data fitting, and used it as the design basis for the cam outer contour line. The cam designed and shaped according to the outer contour line was applied to the harmonic reducer after experiments and verification. It can effectively reduce the stress on the flexible wheel and the flexible bearing in the harmonic reducer, improve the use environment of the flexible wheel and the flexible bearing, and enhance the load-bearing capacity and service life of the harmonic reducer, so that the harmonic reducer has better performance, which solves the problem of how to improve the performance of the harmonic reducer in terms of load-bearing capacity and service life in the prior art.

[0038] This application abandons the inherent design ideas for cams in this field. In the long-term product development and improvement practice, various cam outer contour modification designs are studied to explore the impact on the performance of the harmonic reducer, and the modification curve obtained by using the above-mentioned high-order polynomial equation is obtained. This is a completely different cam design scheme from the past. Through breakthrough designs in details, after the cam is assembled to the harmonic reducer, the performance of the harmonic reducer in many aspects is improved, and outstanding technical effects are achieved through completely different design ideas.

[0039] For example, in a specific embodiment, taking the Sugikawa 25# series harmonic reducer as an example, p1 is -5.05e-9, p2 is 4.262e-7, p3 is -1.471e-5, p4 is 0.0002666, p5 is -0.002715, p6 is 0.01539, p7 is -0.04237, p8 is 0.0373, p9 is 0, and p 10 The value is 22.85, that is, the equation of the first curve 1 of the outer contour line is:

[0040]

[0041] It should be noted that Sugikawa's 25# series harmonic reducers specifically include models such as 25-50, 25-80, 25-100, and 25-120, among which "25" is the specification code, representing that the harmonic gear pitch circle diameter parameter is 63.5mm, and "50", "80", "100", and "120" are reduction ratios.

[0042] Such setting can achieve the best effect among the values ​​that can be explored for this series of harmonic reducers.

[0043] This application also provides a comparison diagram of the cam outer contour lines of the harmonic reducer of the prior art and the harmonic reducer provided in this application under the same model, please refer to Figure 2 and Figure 3 , wherein the solid line is the outer contour line of the cam provided by the present application, and the dotted line is the elliptical cam of the prior art. Figure 3It can be seen that in area A close to the major axis of the cam, the outer contour line of the cam provided by the present application is on the outside, and in area B close to the minor axis, the outer contour line of the cam provided by the present application is on the inside.

[0044] Such an arrangement can increase the curvature of the contact surface between the cam and the wave generator, so that more balls can share the load, further reducing noise and vibration, and improving the load-bearing capacity and service life of the harmonic reducer.

[0045] Although the cam outer contour line of the present application is no longer an ellipse in a strict sense, the major axis and the minor axis can still be distinguished. In combination with the plane rectangular coordinate system, the X-axis direction is the minor axis direction, and the Y-axis direction is the major axis direction.

[0046] In some preferred embodiments, the connection between the first curve 1 and the fourth curve 4, as well as the connection between the second curve 2 and the third curve 3, are all set as transition curves, and the radius of the transition curve is R, 5mm≤R≤30mm. It can also be said that there is a transition fillet modification at the short axis of the cam. In this way, the cam is further modified in the direction of the short axis, and has a rounded transition design. After testing and verification, it can further optimize and improve the performance in reducing the stress on the flexible wheel and the flexible bearing in the harmonic reducer, improving the use environment of the flexible wheel and the flexible bearing, and improving the load-bearing capacity and service life of the harmonic reducer.

[0047] For example, R is 20 mm. Among the values ​​that can be explored, this setting can achieve the best effect.

[0048] It should be noted that the adjustment of many parameters in the equation of the first curve 1 can bring about different degrees of optimized performance. The applicant has obtained the above-mentioned parameter design ranges through a large number of comparative tests, so that a cam with better performance can be obtained within the explorable range.

[0049] Based on the above cam, the embodiment of the present application further provides a wave generator, which includes a flexible bearing and the above cam, and the flexible bearing is sleeved on the cam. Since the wave generator has the above cam, the beneficial effects of the wave generator brought by the cam can be seen in the above content, which will not be repeated here.

[0050] Based on the above-mentioned wave generator, the embodiment of the present application further provides a harmonic reducer, which includes a rigid wheel, a flexible wheel and the above-mentioned wave generator, wherein the wave generator is sleeved inside the flexible wheel, the flexible wheel is sleeved inside the rigid wheel, and the flexible wheel and the rigid wheel are meshed with teeth. Since the harmonic reducer has the above-mentioned wave generator, the beneficial effects of the harmonic reducer brought by the wave generator can be found in the above content, which will not be repeated here.

[0051] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0052] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0053] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0054] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0055] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0056] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A cam, characterized in that: The outer contour line of the cam comprises a first curve (1), a second curve (2), a third curve (3) and a fourth curve (4) connected in sequence. The outer contour line is placed in a plane rectangular coordinate system, the center of the cam is point O, the first curve (1) is located in the first quadrant, the second curve (2) and the first curve (1) are symmetrical about the Y axis, the third curve (3) and the second curve (2) are symmetrical about the X axis, the fourth curve (4) and the first curve (1) are symmetrical about the X axis, and the first curve (1) satisfies the equation: ; x is the horizontal coordinate, f(x) is the vertical coordinate; p1 satisfies -9.267e-9≤p1≤-1.028e-7; p2 satisfies 9.54e-8≤p2≤1.039e-6; p3 satisfies -4.404e-6≤p3≤0.000411; p4 satisfies -0.009594≤p4≤0.01013; p5 satisfies -0.1367≤p5≤0.1313; p6 satisfies -1.062≤p6≤1.093; p7 satisfies -4.943≤p7≤4.852; p8 satisfies -11.19≤p8≤11.26; p9 satisfies -10.1≤p9≤10.05; p 10 Satisfying 20.39≤p 10 ≤25.3; Here, e represents exponential expression in scientific notation.

2. The cam according to claim 1, characterized in that: p1 is -5.05e-9, p2 is 4.262e-7, p3 is -1.471e-5, p4 is 0.0002666, p5 is -0.002715, p6 is 0.01539, p7 is -0.04237, p8 is 0.0373, p9 is 0, p 10 The value is 22.

85.

3. The cam according to claim 1, characterized in that: The connection point between the first curve (1) and the fourth curve (4), and the connection point between the second curve (2) and the third curve (3) are both set as transition curves, and the radius of the transition curve is R, 5mm≤R≤30mm.

4. The cam according to claim 3, characterized in that: The value of R is 20mm.

5. A wave generator, characterized in that: It comprises a flexible bearing and a cam as claimed in any one of claims 1 to 4, wherein the flexible bearing is sleeved on the cam.

6. A harmonic reducer, characterized in that: It comprises a rigid wheel, a flexible wheel and the wave generator as claimed in claim 5.

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