A high-load-bearing and high-precision harmonic flexible gear tooth profile and rigid gear tooth profile

Abstract

A high-load-bearing and high-precision harmonic flexible gear tooth profile and a rigid gear tooth profile are disclosed. The flexible gear tooth profile includes a set of arc surfaces symmetrical about a first tooth tip arc surface and a centerline of the first tooth tip arc surface. The arc surface set includes a first tooth root arc surface, a first root region transition arc surface segment A, a first root region transition arc surface segment B, a first middle region arc surface, and a first top transition arc surface. The first root region transition arc surface segment B and the first middle region arc surface form the gear meshing area. The flexible gear tooth profile is a wide-grooved tooth, and the pressure angle of the flexible gear tooth profile is 10±1°. The rigid gear tooth profile includes a set of arc surfaces symmetrical about a second tooth root arc surface and a centerline of the second tooth root arc surface. The arc surface set includes a second tooth tip arc surface, a second top region transition arc surface, a second top transition region arc surface, a second middle region arc surface, a second root arc surface, and a second root transition region arc surface. It features high precision, high load-bearing capacity, and long service life.

Description

Technical Field

[0001] This utility model belongs to the field of precision harmonic drive technology, and relates to a flexible wheel tooth profile and a rigid wheel tooth profile corresponding to the flexible wheel tooth profile. Specifically, it relates to a high load-bearing and high-precision 14-harmonic flexible wheel tooth profile and a corresponding rigid wheel tooth profile. Background Technology

[0002] A harmonic drive is a geared device that uses a harmonic generator to drive a flexible wheel to elastically deform and transmit motion. It is characterized by its small size and high load-bearing capacity. A harmonic drive consists of three core components: a harmonic generator, a flexible wheel, and a rigid wheel. When the harmonic generator rotates, it induces periodic elastic deformation of the flexible wheel, causing it to mesh with the rigid wheel and transmit motion, thus achieving a speed reduction effect.

[0003] The tooth profiles of the rigid and flexible gears in traditional harmonic reducers have evolved from the straight tooth profile used by Walt Musser to the involute tooth profile, and then to the IH tooth profile (also known as the S tooth profile) and the P tooth profile (also known as the short tooth profile). This has significantly improved the load-bearing capacity and service life of both the rigid and flexible gear tooth profiles. However, the IH tooth profile, which is widely used at present, has very high requirements for the processing technology of the flexible gear and the production process is complicated. The P tooth profile, due to its shorter tooth profile, is prone to reduced accuracy and lifespan after the harmonic reducer is loaded. Therefore, neither of these is conducive to use. Summary of the Invention

[0004] The first technical problem to be solved by this utility model is to provide a high-load-bearing and high-precision harmonic flexible gear tooth profile that addresses the above-mentioned technical situation. This profile features a scientifically sound design, high precision, and long service life.

[0005] The second technical problem to be solved by this utility model is to provide a rigid wheel tooth profile that corresponds to the aforementioned flexible wheel tooth profile, in view of the above-mentioned technical status quo.

[0006] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: a high-load-bearing and high-precision harmonic flexible gear tooth profile, characterized in that: the flexible gear tooth profile includes a group of arc surfaces symmetrical about the first tooth tip arc surface and the center line of the first tooth tip arc surface. The group of arc surfaces includes a first tooth root arc surface, a first root region transition arc surface, a first middle region arc surface, and a first top transition arc surface connected in sequence. The first root region transition arc surface includes a first root region transition arc surface segment A and a first root region transition arc surface segment B. The first root region transition arc surface segment B and the first middle region arc surface are the gear meshing area. The flexible gear tooth profile is a wide-groove tooth, and the pressure angle of the flexible gear tooth profile is 10±1°.

[0007] As an improvement, the first root arc surface and the first root region transition arc surface B segment are connected tangentially by the first root region transition arc surface A segment; the first root region transition arc surface A segment and the middle region arc surface are connected tangentially by the first root region transition arc surface B segment; the first root region transition arc surface B segment and the first top transition arc surface are connected tangentially by the first middle region arc surface; and the first middle region arc surface and the first tooth tip arc surface are connected tangentially by the first top transition arc surface.

[0008] Furthermore, the arc length of the first tooth tip arc surface is 0.0408±0.005mm, the arc length of the first tooth root arc surface is 0.0512±0.005mm, the arc length of segment A of the first root region transition arc surface is 0.0512±0.005mm, and the radius is R0.1±0.01mm; the arc length of segment B of the first root transition region arc surface is 0.0822±0.005mm, and the radius is R2.2±0.1mm; the arc length of the first middle region arc surface is 0.1207±0.005mm, and the radius is R0.345±0.05mm; and the arc length of the first top transition arc surface is 0.0254±0.005mm, and the radius is R0.052±0.01mm.

[0009] Finally, the height ratio of the first root arc surface is 28±1%, and the height ratio of the middle arc surface and the transition arc surface B segment of the first root area is 68±1%.

[0010] The technical solution adopted by this utility model to solve the second technical problem mentioned above is as follows: a high-load-bearing and high-precision harmonic rigid wheel tooth profile, characterized in that: the rigid wheel tooth profile includes a group of arc surfaces that are axially symmetrical about the second tooth root arc surface and the center line of the second tooth root arc surface. The arc surface group includes a second tooth tip arc surface, a second top area transition arc surface, a second top transition area arc surface, a second middle area arc surface, a second root arc surface, and a second root transition area arc surface connected in sequence. The second top transition area arc surface includes a second top transition area arc surface segment A and a second top transition area arc surface segment B. The second middle area arc surface and the second root arc surface are meshing surfaces that mesh with the above-mentioned flexible wheel tooth profile.

[0011] As an improvement, the second tooth tip arc surface and the second top transition area arc surface A segment are tangentially connected by the second top area transition arc surface; the second top area transition arc surface and the second top transition area arc surface B segment are tangentially connected by the second top transition area arc surface A segment; the second top transition area arc surface A segment and the second middle area arc surface are tangentially connected by the second top transition area arc surface B segment; the second top transition area arc surface B segment and the second root arc surface are tangentially connected by the second middle area arc surface; the second middle area arc surface and the second root transition arc surface are tangentially connected by the second root arc surface; and the second root arc surface and the second tooth root arc surface are tangentially connected by the second root transition arc surface.

[0012] Finally, the arc length of the second tooth tip arc surface is 0.1022±0.005mm; the arc length of the second top region transition arc surface is 0.022±0.005mm, and the radius is R0.026±0.005mm; the arc length of segment A of the second top transition region arc surface is 0.0118±0.005mm, and the radius is R0.2162±0.01mm; the arc length of segment B of the second top transition region arc surface is 0.0118±0.005mm, and the radius is R0.2162±0.01mm. 0.02mm; the arc length of the second central region arc surface is 0.0682±0.01mm, and the radius is R0.8991±0.1mm; the arc length of the second root arc surface is 0.1565±0.01mm, and the radius is R0.3462±0.005mm; the arc length of the second root transition arc surface is 0.0291±0.005mm, and the radius is R0.0343±0.005mm; the arc length of the second tooth root arc surface is 0.0099mm±0.001mm.

[0013] Compared with the prior art, the advantages of this utility model are:

[0014] 1. Advantages of the flexible gear tooth profile: The pressure angle of the flexible gear tooth profile is designed at 10°, which is much smaller than that of common flexible gear tooth profiles. This increases the gear contact ratio and reduces noise. The optimized tooth tip arc transition effectively improves the interference problem during tooth meshing. The increased tooth groove width relative to the tooth thickness and the increased R angle at the tooth root mitigate stress concentration. The root arc height accounts for 28%, greatly improving the bending fatigue strength of the flexible gear. The tooth profile is a wide-groove tooth, and the stress in the flexural gear rim will be greatly reduced as the groove width on the root circle increases, which is more conducive to the bending of the flexible gear. The arc surface in the middle area and the transition arc surface B section of the first root area are the gear meshing area, with a height ratio of 68%, which greatly improves the gear contact ratio and strength. This tooth profile can continuously contact similar tooth profiles, and the gear clearance away from the cam shaft can remain unchanged until disengagement, resulting in a high contact ratio. At the same time, the number of meshing teeth can reach 40% to 50% of the total number of teeth, greatly improving the load-bearing capacity of the flexible gear.

[0015] 2. Advantages of rigid wheel tooth profile: The design of the transition arc effectively solves the problem of interference between the rigid wheel and the flexible wheel tooth profile; the second middle arc surface and the second root arc surface are the meshing surfaces, which increases the meshing surface between the rigid wheel and the flexible wheel, thereby improving the tooth profile load-bearing capacity and overlap rate of the rigid wheel and the flexible wheel, reducing noise and increasing strength; the stress distribution of the rigid wheel to the flexible wheel is optimized, the problem of stress concentration on the flexible wheel tooth surface is improved, and the service life of the rigid wheel and the flexible wheel is increased; the rigid wheel tooth profile can be formed by the envelope method, which is simple, convenient and efficient.

[0016] This utility model has a reasonable structural design and features high precision, high load-bearing capacity, and long service life. Furthermore, the total number of meshing teeth between the rigid wheel and the flexible wheel is over 50%, ensuring no interference between the rigid and flexible wheels during movement, and the gear overlap is high during movement. Attached Figure Description

[0017] Figure 1 A curve diagram of the flexible gear tooth profile in an embodiment of this utility model;

[0018] Figure 2 A curve diagram of the tooth profile of the rigid wheel according to an embodiment of this utility model;

[0019] Figure 3 for Figure 1 A schematic diagram of the flexible structure after the elliptical array of the flexible wheel teeth is deformed according to the inner hole of the flexible wheel;

[0020] Figure 4 for Figure 2 A schematic diagram of the structure of the rigid wheel tooth profile, showing the entire circle of the rigid wheel tooth profile according to the number and tooth tip circle.

[0021] Figure 5 A schematic diagram showing the rigid wheel and the flexible wheel coinciding with their centers;

[0022] Figure 6 A schematic diagram showing the maximum meshing of a single tooth of a rigid wheel and a flexible wheel;

[0023] Figure 7 This is a schematic diagram simulating the motion trajectory of a flexible wheel. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] like Figures 1-4As shown, a high-load-bearing and high-precision 14-harmonic flexible gear tooth profile 100 includes a first tooth tip arc surface 6 and an arc surface group symmetrical about the center line of the first tooth tip arc surface 6. The arc surface group includes a first tooth root arc surface 1, first root region transition arc surfaces 2 and 3, first middle region arc surface 4, and first top transition arc surface 5 connected in sequence. The first root region transition arc surfaces 2 and 3 include a first root region transition arc surface A segment 2 and a first root region transition arc surface B segment 3 connected in sequence. The first root region transition arc surface B segment 3 and the first middle region arc surface 4 are the gear meshing area. The flexible gear tooth profile 100 is a wide-groove tooth, and the pressure angle of the flexible gear tooth profile 100 is 10±1°.

[0026] The first root arc surface 1 and the first root region transition arc surface B segment 3 are connected tangentially to each other by the first root region transition arc surface A segment 2. The first root region transition arc surface A segment 2 and the middle region arc surface 4 are connected tangentially to each other by the first root region transition arc surface B segment 3. The first root region transition arc surface B segment 3 and the first top transition arc surface 5 are connected tangentially to each other by the first middle region arc surface 4. The first middle region arc surface 4 and the first tooth tip arc surface 6 are connected tangentially to each other by the first top transition arc surface 5.

[0027] The arc length of the first tooth tip arc surface 6 is 0.0408±0.005mm, the arc length of the first tooth root arc surface 1 is 0.0512±0.005mm, the arc length of the first root transition arc surface A segment 2 is 0.0512±0.005mm, and the radius is R0.1±0.01mm; the arc length of the first root transition arc surface B segment 3 is 0.0822±0.005mm, and the radius is R2.2±0.1mm; the arc length of the first middle region arc surface 4 is 0.1207±0.005mm, and the radius is R0.345±0.05mm; the arc length of the first top transition arc surface 5 is 0.0254±0.005mm, and the radius is R0.052±0.01mm.

[0028] The height ratio of the first root arc surface 1 is 28±1%, and the height ratio of the first middle area arc surface 4 and the first root area transition arc surface B segment 3 is 68±1%.

[0029] The flexible gear tooth profile 100 of this embodiment has the following advantages:

[0030] 1. The pressure angle of this tooth profile is 10°, which is much smaller than that of common flexible gear tooth profiles. This can increase the overlap of gears and reduce noise.

[0031] 2. The tooth tip arc transition has been optimized, which greatly improves the interference problem during tooth meshing;

[0032] 3. Enlarging the width of the tooth groove relative to the tooth thickness and increasing the radius of the tooth root alleviates stress concentration.

[0033] 4. The height of the first tooth root arc surface accounts for 28%, which greatly improves the bending fatigue strength of the flexible gear.

[0034] 5. This tooth profile is a wide groove tooth. The stress in the flexure rim will be greatly reduced as the groove width on the root circle increases, which is more conducive to the bending of the flexure.

[0035] 6. The transition arc surface in the middle section and the first root section, section B, is the gear meshing area, accounting for 68% of the height, which greatly improves the overlap and strength of the gear.

[0036] 7. This tooth profile can continuously contact similar tooth profiles, and the gear clearance away from the long shaft of the cam can remain unchanged until disengagement, with a high overlap rate. At the same time, the number of meshing teeth can reach 40% to 50% of the total number of teeth, which greatly improves the load-bearing capacity of the flexible gear.

[0037] A rigid gear tooth profile 200 includes a group of arc surfaces symmetrical about a second tooth root arc surface 80 and a centerline of the second tooth root arc surface 80. The group of arc surfaces includes a second tooth tip arc surface 10, a second top region transition arc surface 20, second top transition region arc surfaces 30 and 40, a second middle region arc surface 50, a second root arc surface 60, and a second root transition region arc surface 70 connected in sequence. The second top transition region arc surfaces 30 and 40 include a second top transition region arc surface A segment 30 and a second top transition region arc surface B segment 40. The second middle region arc surface 50 and the second root arc surface 60 are meshing surfaces that mesh with the aforementioned flexible gear tooth profile 100.

[0038] The second tooth tip arc surface 10 and the second top transition area arc surface A segment 30 are tangentially connected by the second top transition area arc surface 20. The second top transition area arc surface 20 and the second top transition area arc surface B segment 40 are tangentially connected by the second top transition area arc surface A segment 30. The second top transition area arc surface A segment 30 and the second middle area arc surface 50 are tangentially connected by the second top transition area arc surface B segment 40. The second top transition area arc surface B segment 40 and the second root arc surface 60 are tangentially connected by the second middle area arc surface 05. The second middle area arc surface 50 and the second root transition arc surface 70 are tangentially connected by the second root arc surface 60. The second root arc surface 60 and the second tooth root arc surface 80 are tangentially connected by the second root transition arc surface 70.

[0039] The arc length of the second tooth tip arc surface 10 is 0.1022±0.005mm; the arc length of the second top region transition arc surface 20 is 0.022±0.005mm, and the radius is R0.026±0.005mm; the arc length of segment A 30 of the second top transition region arc surface is 0.0118±0.005mm, and the radius is R0.2162±0.01mm; the arc length of segment B 40 of the second top transition region arc surface is 0.0118±0.005mm, and the radius is R0.2162±0.01mm. 0.02mm; the arc length of the second central region arc surface 50 is 0.0682±0.01mm, and the radius is R0.8991±0.1mm; the arc length of the second root arc surface 60 is 0.1565±0.01mm, and the radius is R0.3462±0.005mm; the arc length of the second root transition arc surface 70 is 0.0291±0.005mm, and the radius is R0.0343±0.005mm; the arc length of the second tooth root arc surface 80 is 0.0099±0.001mm.

[0040] The rigid wheel tooth profile 200 of this embodiment has the following advantages:

[0041] 1. By designing the transition arc, the problem of tooth interference between the rigid wheel and the flexible wheel is effectively solved;

[0042] 2. By designing the meshing surfaces (the second central arc surface and the second root arc surface are the meshing surfaces), the meshing surface between the rigid wheel and the flexible wheel is increased, thereby improving the tooth profile load-bearing capacity and overlap rate of the rigid wheel and the flexible wheel, reducing noise and increasing strength.

[0043] 3. The stress distribution between the rigid wheel and the flexible wheel was optimized, the problem of stress concentration on the tooth surface of the flexible wheel was improved, and the service life of the rigid wheel and the flexible wheel was increased.

[0044] 4. The tooth profile of this steel wheel 200 can be formed by the enveloping method, which is simple, convenient and efficient.

[0045] The following describes the meshing of a model 14 rigid wheel and a flexible gear with a speed ratio of 100:

[0046] 1. Arrange the deformed flexible wheel into an elliptical array according to the deformation of the flexible wheel tooth profile 100 based on the inner hole of the flexible wheel, such as... Figure 3 ;

[0047] 2. Arrange the individual rigid wheel teeth 200 according to the quantity and tooth tip circle to form the complete circle of rigid wheel tooth shape, as shown in the example. Figure 4 ;

[0048] 3. By aligning the rigid wheel and the flexible wheel at their centers, it can be seen that the total ratio of meshing teeth between the rigid wheel and the flexible wheel is approximately 50%. (See [reference]). Figure 5 ;

[0049] 4. It can be seen that the tooth surface overlap rate of the rigid wheel and the flexible wheel at maximum meshing of a single tooth is over 80%. (See [reference]). Figure 6 ;

[0050] 5. Simulating the motion trajectory of the flex wheel shows that there is no interference between the flex wheel and the rigid wheel during motion, and the gear overlap is high during motion. (See [reference]). Figure 7 .

[0051] In this embodiment, the rigid gear tooth profile 200 and the flexible gear tooth profile 100 are formed using the envelope method, also known as the generating method, the producing method, or the conjugate method. This is currently one of the most commonly used methods in gear manufacturing. It is based on the principle that when a pair of gears mesh, their tooth profiles are conjugate curves. Therefore, the rigid gear and flexible gear in this embodiment are highly operable and the manufacturing process is simple.

[0052] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A high load capacity high precision harmonic flexspline tooth profile, characterized by: The flexible gear tooth profile includes a set of arc surfaces symmetrical about the first tooth tip arc surface and the centerline of the first tooth tip arc surface. The set of arc surfaces includes a first tooth root arc surface, a first root region transition arc surface, a first middle region arc surface, and a first top transition arc surface connected in sequence. The first root region transition arc surface includes a first root region transition arc surface segment A and a first root region transition arc surface segment B. The first root region transition arc surface segment B and the first middle region arc surface are the gear meshing area. The flexible gear tooth profile is a wide-grooved tooth, and the pressure angle of the flexible gear tooth profile is 10±1°.

2. The harmonic wave generator tooth profile of claim 1, wherein: The first root arc surface and the first root region transition arc surface segment B are connected tangentially to each other by the first root region transition arc surface segment A. The first root region transition arc surface segment A and the middle region arc surface are connected tangentially to each other by the first root region transition arc surface segment B. The first root region transition arc surface segment B and the first top transition arc surface are connected tangentially to each other by the first middle region arc surface. The first middle region arc surface and the first tooth tip arc surface are connected tangentially to each other by the first top transition arc surface.

3. The harmonic wave generator tooth profile of claim 2, wherein: The arc length of the first tooth tip arc surface is 0.0408±0.005mm, the arc length of the first tooth root arc surface is 0.0512±0.005mm, the arc length of segment A of the first root transition arc surface is 0.0512±0.005mm, and the radius is R0.1±0.01mm; the arc length of segment B of the first root transition arc surface is 0.0822±0.005mm, and the radius is R2.2±0.1mm; the arc length of the first middle arc surface is 0.1207±0.005mm, and the radius is R0.345±0.05mm; the arc length of the first top transition arc surface is 0.0254±0.005mm, and the radius is R0.052±0.01mm.

4. The harmonic wave generator tooth profile of claim 3, wherein: The height ratio of the first root arc surface is 28±1%, and the height ratio of the middle arc surface and the transition arc surface B segment of the first root region is 68±1%.

5. A high load capacity high precision harmonic gear tooth profile, characterized by: The rigid wheel tooth profile includes a group of arc surfaces that are axially symmetrical about the second tooth root arc surface and the centerline of the second tooth root arc surface. The group of arc surfaces includes a second tooth tip arc surface, a second top region transition arc surface, a second top transition region arc surface, a second middle region arc surface, a second root arc surface, and a second root transition region arc surface connected in sequence. The second top transition region arc surface includes a second top transition region arc surface segment A and a second top transition region arc surface segment B. The second middle region arc surface and the second root arc surface are meshing surfaces that mesh with the flexible wheel tooth profile described in claim 1.

6. The harmonic-rack tooth profile of claim 5, wherein: The second tooth tip arc surface and the second top transition area arc surface A are tangentially connected by the second top transition area arc surface. The second top transition area arc surface and the second top transition area arc surface B are tangentially connected by the second top transition area arc surface A. The second top transition area arc surface A and the second middle area arc surface are tangentially connected by the second top transition area arc surface B. The second top transition area arc surface B and the second root arc surface are tangentially connected by the second middle area arc surface. The second middle area arc surface and the second root transition arc surface are tangentially connected by the second root arc surface. The second root arc surface and the second tooth root arc surface are tangentially connected by the second root transition arc surface.

7. The harmonic-rack tooth profile of claim 6, wherein: The arc length of the second tooth tip arc surface is 0.1022±0.005mm; the arc length of the second top region transition arc surface is 0.022±0.005mm, and the radius is R0.026±0.005mm; the arc length of segment A of the second top transition region arc surface is 0.0118±0.005mm, and the radius is R0.2162±0.01mm; the arc length of segment B of the second top transition region arc surface is 0.0118±0.005mm, and the radius is R0.2162±0.01mm. 0.02mm; the arc length of the second central region arc surface is 0.0682±0.01mm, and the radius is R0.8991±0.1mm; the arc length of the second root arc surface is 0.1565±0.01mm, and the radius is R0.3462±0.005mm; the arc length of the second root transition arc surface is 0.0291±0.005mm, and the radius is R0.0343±0.005mm; the arc length of the second tooth root arc surface is 0.0099mm±0.001mm.

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