Flexible gear and harmonic reducer

Abstract

The application provides a flexible gear and a harmonic reducer. The flexible gear comprises a flexible gear cylinder and a flexible gear tooth. The circumferential surface of the flexible gear cylinder comprises a non-tooth area and a tooth area distributed in the axial direction. The flexible gear tooth is formed in the tooth area. A groove is arranged in the non-tooth area. The groove extends at least in the axial direction of the flexible gear cylinder. The groove can store lubricating grease and can drain the lubricating grease to the tooth area. In this way, the flexible gear provided by the application is applied to the harmonic reducer. The flexible gear and the rigid gear are assembled and matched. The groove can form a capillary effect on the lubricating grease, that is, the lubricating grease can be stored in the groove, the ability of the flexible gear to store lubricating grease on the surface is improved, meanwhile, the groove has a certain extension span in the axial direction of the flexible gear cylinder, and the lubricating grease can also be drained to the flexible gear tooth in the tooth area, thereby solving the problem of insufficient or dry lubricating grease in the tooth engagement between the flexible gear and the rigid gear.

Description

Technical Field

[0001] This application relates to the field of harmonic reducer technology, specifically to a flexible wheel and a harmonic reducer. Background Technology

[0002] Harmonic reducers are mainly composed of a rigid wheel, a flexible wheel, and a wave generator. They are gear transmission structures that rely on the wave generator to cause the flexible wheel to produce controllable elastic deformation and mesh with the rigid wheel to transmit motion and power.

[0003] During the meshing process of the rigid and flexible gears, the grease inside the harmonic reducer is crucial to the meshing efficiency. Insufficient grease will cause premature wear of the teeth of both the rigid and flexible gears, and may even lead to breakage and failure. However, in related technologies, traditional harmonic reducers often suffer from insufficient grease or grease drying out during tooth meshing. Summary of the Invention

[0004] In view of this, this application provides a flexible gear and a harmonic reducer to solve the problem of insufficient grease or dry grease in the tooth meshing of the prior art harmonic reducer.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A flexible wheel includes a flexible wheel cylinder and flexible wheel teeth;

[0007] The peripheral surface of the flexible wheel cylinder includes a non-toothed area and a toothed area distributed along the axial direction, and the flexible wheel teeth are formed in the toothed area;

[0008] The non-toothed area is provided with grooves that extend at least in the axial direction of the flexible cylinder. The grooves can store grease and guide the grease to the toothed area.

[0009] Optionally, the grooves are mesh-like; and / or, the grooves cover the non-toothed area.

[0010] Optionally, the grooves include a first twill and a second twill, wherein the first twill and the second twill are distributed in an alternating pattern;

[0011] Both the first and second twill lines extend along the axial and circumferential directions of the flexible wheel cylinder, and on a projection plane parallel to the axis of the flexible wheel cylinder, the first and second twill lines have a non-right angle between them.

[0012] Optionally, the acute angle between the first twill and the second twill is θ, where 20°≤θ≤40°.

[0013] Optionally, the acute angle between the first twill and the axis of the flexible wheel cylinder is α, where 60°≤α≤80°;

[0014] The acute angle between the second twill and the axis of the flexible wheel cylinder is β, where 60°≤β≤80°.

[0015] Optionally, in the axial direction of the flexible cylinder, the distance between two adjacent first oblique lines is H1, and the distance between two adjacent second oblique lines is H2, where H1=H2.

[0016] Optionally, in the tooth region, the wall thickness of the flexible cylinder corresponding to the root of the flexible tooth is D;

[0017] The flexible wheel also includes a cap edge that is transitionally connected to the end of the flexible wheel cylinder. In the non-toothed area, the flexible wheel cylinder includes a first section, a second section, a third section, and a fourth section distributed sequentially. The first section is close to the toothed area, and the fourth section is close to the transition angle of the cap edge. The wall thickness of the first section is D1, the wall thickness of the second section is D2, the wall thickness of the third section is D3, and the wall thickness of the fourth section is D4.

[0018] Where: D≥D4, D1=D2>D3>D4.

[0019] Optionally, the grooves are distributed in the first segment, the second segment, and the third segment, with the grooves in the first segment having an opening depth of d1, the grooves in the second segment having an opening depth of d2, and the grooves in the third segment having an opening depth of d3, where D4 > d1 = d2 > d3.

[0020] Optionally, d2 = d1 = a × D1, 0.3 ≤ a ≤ 0.35;

[0021] d3 = b × D3, 0.2 ≤ b ≤ 0.25.

[0022] A harmonic reducer includes a wave generator, a rigid wheel, and a flexible wheel as described above, wherein the wave generator is fitted inside the flexible wheel, and the flexible wheel is fitted inside the rigid wheel and meshes with the teeth of the rigid wheel.

[0023] The flexible gear provided in this application is applied to a harmonic reducer. The flexible gear includes a flexible gear cylinder and flexible gear teeth. The peripheral surface of the flexible gear cylinder includes a non-tooth region and a tooth region distributed along the axial direction, and the flexible gear teeth are formed in the tooth region. Grooves are provided in the non-tooth region, and the grooves extend at least in the axial direction of the flexible gear cylinder. The grooves can store grease and guide the grease to the tooth region. With this configuration, when the flexible gear provided in this application is applied to a harmonic reducer, the flexible gear and the rigid gear are assembled and matched. The grooves can form a capillary effect on the lubricating grease, that is, the lubricating grease can be stored in the grooves, improving the surface of the flexible gear's ability to store lubricating grease. At the same time, the grooves have a certain extension span in the axial direction of the flexible gear cylinder, which can also guide the lubricating grease to the flexible gear teeth in the tooth region, thereby solving the problem of insufficient grease meshing or grease drying between the flexible gear and the rigid gear. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is an isometric view of the flexible wheel provided in an embodiment of this application.

[0026] Figure 2 A side view of a flexible wheel provided in an embodiment of this application.

[0027] Figure 3 A front view of the flexible wheel provided in an embodiment of this application.

[0028] Figure 4 for Figure 3 Sectional view at point CC.

[0029] Figure 5 for Figure 4 Detailed view of point A in the middle.

[0030] Figure 6 This is an assembly diagram of the harmonic reducer provided in an embodiment of this application.

[0031] exist Figures 1-6 middle:

[0032] 1. Flexible wheel; 2. Rigid wheel; 3. Cam; 4. Flexible bearing; 5. Crossed roller bearing; 6. Rear cover; 7. Front cover; 8. Deep groove ball bearing; 9. Oil seal;

[0033] 11. Flexible gear cylinder; 12. Flexible gear teeth; 13. Brim;

[0034] 111. Non-dental area; 112. Dental area;

[0035] 1100, Groove; 1101, First Twill; 1102, Second Twill. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] In its production practice, the applicant discovered that during the operation of the harmonic reducer, when the rigid gear 2 and the flexible gear 1 mesh, the proportion of lubricating grease involved in lubrication varies depending on the operating conditions. During normal use, the harmonic reducer throws the lubricating grease to various internal locations. Due to the structural limitations of the flexible gear 1, its surface cannot store sufficient lubricating grease, and the grease generally flows to the bottom of the cap of the flexible gear 1, failing to return to the teeth, thus affecting the usability of the lubricating grease.

[0038] like Figures 1-5 As shown, this application provides a flexible gear 1 for use in a harmonic reducer. The flexible gear 1 includes a flexible gear cylinder 11 and flexible gear teeth 12. The peripheral surface of the flexible gear cylinder 11 includes a non-tooth region 111 and a tooth region 112 continuously distributed along the axial direction. The flexible gear teeth 12 are formed in the tooth region 112, and are generally integrally formed on the flexible gear cylinder 11. Grooves 1100 are provided in the non-tooth region 111. The grooves 1100 extend at least in the axial direction of the flexible gear cylinder 11. The grooves 1100 can store grease and guide grease to the tooth region 112. The grooves 1100 are recessed relative to the surface of the flexible gear cylinder 11, that is, the grooves 1100 are formed by a partial material loss in the flexible gear cylinder 11.

[0039] With this configuration, the flexible wheel 1 provided in this application is applied to the harmonic reducer. The flexible wheel 1 and the rigid wheel 2 are assembled and matched. The groove 1100 can form a capillary effect on the lubricating grease, that is, the lubricating grease can be stored in the groove 1100, which improves the surface of the flexible wheel 1's ability to store lubricating grease. At the same time, the groove 1100 has a certain extension span in the axial direction of the flexible wheel cylinder 11, which can also guide the lubricating grease to the flexible wheel teeth 12 in the tooth area 112. This solves the problem of insufficient grease or grease drying between the teeth of the flexible wheel 1 and the rigid wheel 2, avoids premature wear of the teeth of the harmonic reducer, and effectively solves the problem of insufficient lubrication affecting the meshing efficiency of the harmonic reducer. This is conducive to more efficient operation of the harmonic reducer and improves the service life of the harmonic reducer.

[0040] This application abandons the conventional design approach in the field of improving the lubrication between the flexible gear 1 and the rigid gear 2 by modifying the teeth of the flexible gear 12 or the rigid gear 2. Through long-term product development and improvement practices, the influence of various flexible gear 1 designs on the lubrication of the harmonic reducer has been investigated, resulting in a structural improvement design for the non-tooth region 111 of the flexible gear cylinder 11—a completely different design solution from the past. Through this breakthrough design in detail, the lubrication during meshing of the flexible gear 1 and the rigid gear 2 is improved, thereby enhancing the performance of the harmonic reducer. This entirely different design approach has achieved outstanding technical results.

[0041] It should be noted that the flexible wheel 1 provided in this application can be any cylindrical flexible wheel 1 that already exists in the prior art, and can be, but is not limited to, cup-shaped, cap-shaped, and straight cylindrical types, etc.

[0042] Regarding the distribution pattern of the grooves 1100, in some optional embodiments, the grooves 1100 are distributed in a mesh pattern in the non-tooth region 111. This arrangement, provided the structural strength allows, not only increases the space available for storing lubricating grease but also provides more possibilities for grease flow, helping to further ensure that the lubricating grease can be guided to the tooth region 112, and further improving the uniform and sufficient lubrication of the teeth.

[0043] Of course, in addition to the above methods, it is also possible in some cases for the groove 1100 to be constructed as a straight line extending along the axial direction and having multiple parallel lines.

[0044] Regarding the distribution pattern of the grooves 1100, in some optional embodiments, the grooves 1100 cover the non-tooth region 111, that is, the grooves 1100 extend to the position of the non-tooth region 111 near the tooth region 112. With this arrangement, provided the structural strength allows, the grooves 1100 are distributed as fully as possible in the non-tooth region 111, which not only increases the space for storing lubricating grease but also increases the possibilities for the flow of lubricating grease, helping to further ensure that the lubricating grease can be guided to the tooth region 112, and further improving the sufficient lubrication of the teeth by the lubricating grease.

[0045] Of course, in addition to the above methods, it is also feasible to distribute the grooves 1100 locally in the non-tooth area 111 in some cases.

[0046] In some specific embodiments, the groove 1100 includes a first twill 1101 and a second twill 1102, each having multiple first twill 1101 and second twill 1102, which are distributed intersectingly. Both the first twill 1101 and second twill 1102 extend along the axial and circumferential directions of the flexible wheel cylinder 11, and on a projection plane parallel to the axis of the flexible wheel cylinder 11, the first twill 1101 and second twill 1102 form a non-right-angled angle. That is, the groove 1100 is constructed in a diamond-shaped mesh pattern.

[0047] With this configuration, the grooves 1100 with the above-mentioned double oblique cross design not only increase the space for storing lubricating grease on the surface of the flexible gear cylinder 11, but also facilitate the formation of a return flow of lubricating grease on the surface of the flexible gear 1. By increasing the storage capacity and fluidity of lubricating grease, the feasibility of lubricating grease returning to the tooth area 112 is further improved, thereby optimizing the lubrication conditions of the teeth of the harmonic reducer and making the meshing of the rigid gear 2 and the flexible gear 1 smoother.

[0048] In some other specific embodiments, the acute angle between the first twill 1101 and the second twill 1102 is θ, where 20° ≤ θ ≤ 40°. For example, the acute angle between the first twill 1101 and the second twill 1102 is preferably set to 29°. Through experimentation and verification, this setting, when the angle between the first twill 1101 and the second twill 1102 is designed within the above range, achieves the best effect among the exploratory values.

[0049] In some other specific embodiments, the acute angle between the first twill 1101 and the axis of the flexible wheel 11 is α, 60°≤α≤80°; the acute angle between the second twill 1102 and the axis of the flexible wheel 11 is β, 60°≤β≤80°. For example, the acute angle between the first twill 1101 and the axis of the flexible wheel 11 is preferably designed to be 75°, and the acute angle between the second twill 1102 and the axis of the flexible wheel 11 is preferably designed to be 75°. With this configuration, after testing and verification, when the angles between the first twill 1101 and the second twill 1102 and the axis of the flexible wheel 11 are designed within the above range, this achieves the best effect among the values ​​that can be explored.

[0050] In some other specific embodiments, the distance between two adjacent first oblique lines 1101 along the axial direction of the flexible gear cylinder 11 is H1, and the distance between two adjacent second oblique lines 1102 is H2, where H1=H2. This ensures that the axial distances between adjacent first oblique lines 1101 and adjacent second oblique lines 1102 are equal, and the distribution of the first oblique lines 1101 and second oblique lines 1102 on the flexible gear cylinder 11 is highly symmetrical. When the flexible gear 1 is applied to a harmonic reducer, it helps to distribute the force on the flexible gear 1 more evenly, thus optimizing the performance of the harmonic reducer under various operating conditions.

[0051] In some other specific embodiments, in the tooth region 112, the wall thickness of the flexible wheel cylinder 11 corresponding to the tooth root of the flexible wheel tooth 12 is D; the flexible wheel also includes a cap 13 that is transitionally connected to the end of the flexible wheel cylinder 11, that is, the flexible wheel is a cap-shaped flexible wheel. In the non-tooth region 111, the flexible wheel cylinder 11 includes a first segment, a second segment, a third segment and a fourth segment distributed in sequence. The first segment is close to the tooth region 112, and the fourth segment is close to the transition angle of the cap 13 (that is, the R angle shown in Figure 5). Figures 1-5 The flexure 1 is exemplarily shown as a cap shape, with the wall thickness of the first segment being D1, the second segment D2, the third segment D3, and the fourth segment D4; where D ≥ D4, and D1 = D2 > D3 > D4. The wall thickness of the flexure cylinder 11 is also the difference between its radial outer diameter and inner diameter. It should be noted that there are transitional connections between adjacent segments where the wall thickness changes. Thus, in the non-tooth region 111, the wall thickness of the flexure cylinder 11 gradually thins from the side closest to the tooth region 112 to the other side, with the thinnest part having a wall thickness of D4.

[0052] Furthermore, in some specific embodiments, the grooves 1100 are distributed in the first, second, and third sections. The groove depth 1100 in the first section is d1, the groove depth 1100 in the second section is d2, and the groove depth 1100 in the third section is d3, where D4 > d1 = d2 > d3. This configuration ensures that the flexible wheel 1 has sufficient strength to participate in the normal operation of the harmonic reducer while constructing the grooves 1100, and the groove depth is adaptively and gradually adjusted, thus improving the feasibility of the solution.

[0053] Furthermore, based on the above embodiments, in some specific embodiments, d2=d1=a×D1, 0.3≤a≤0.35; d3=b×D3, 0.2≤b≤0.25. With this setting, the groove depth 1100 in the non-tooth region 111 of the flexible wheel 1 is designed as a linear function relationship with the wall thickness of the flexible wheel 1. By varying the values ​​of a and b, the groove depth 1100 is obtained, which is sufficient to ensure the strength and performance of the flexible wheel 1. Through testing and verification, the flexible wheel 1 designed according to the above proportional range ensures that after the flexible wheel 1 is assembled into the harmonic reducer, the harmonic reducer exhibits excellent performance and lubrication under various operating conditions during operation.

[0054] Based on the aforementioned flexible wheel 1, this application embodiment also provides a harmonic reducer, such as... Figure 6 As shown, the harmonic reducer includes a wave generator, a rigid wheel 2, and the aforementioned flexible wheel 1. The wave generator is fitted inside the flexible wheel 1, and the flexible wheel 1 is fitted inside the rigid wheel 2 and meshes with the rigid wheel 2. Since the harmonic reducer has the aforementioned flexible wheel 1, the beneficial effects brought by the flexible wheel 1 are described above and will not be repeated here.

[0055] It should be noted that after the flexible wheel 1 is assembled, due to the effect of the wave generator, the flexible wheel 1 is elliptical, while the flexible wheel 1 is perfectly round in its natural split state.

[0056] In some specific embodiments, the wave generator includes an elliptical cam 3 and a flexible bearing 4, the flexible bearing 4 being fitted over the elliptical cam 3. Exemplarily, the wave generator is connected to a motor shaft as an input.

[0057] In the assembly of the harmonic reducer, the cooperation of components such as crossed roller bearing 5, deep groove ball bearing 8, and skeleton oil seal 9 is also required. This part is a conventional adaptive design in the prior art. For example, the outer ring of the crossed roller bearing 5 is connected to the flexure 1 and the rear cover 6 as the fixed end, and the inner ring of the crossed roller bearing 5 is connected to the rigid wheel 2 and the front cover 7 as the output end.

[0058] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0059] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0060] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0061] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0062] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0063] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A flexible wheel, characterized in that, It includes a flexible wheel cylinder (11), a flexible wheel tooth (12), and a cap (13), wherein the cap (13) is transitionally connected to the end of the flexible wheel cylinder (11); The peripheral surface of the flexible cylinder (11) includes a non-toothed area (111) and a toothed area (112) distributed along the axial direction, and the flexible teeth (12) are formed in the toothed area (112). The non-toothed area (111) is provided with grooves (1100) and the toothed area (112) is not provided with grooves (1100). The grooves (1100) include a first oblique groove (1101) and a second oblique groove (1102), and the first oblique groove (1101) and the second oblique groove (1102) are intersectingly distributed. The first twill (1101) and the second twill (1102) both extend along the axial and circumferential directions of the flexible cylinder (11), and on the projection plane parallel to the axis of the flexible cylinder (11), the first twill (1101) and the second twill (1102) have a non-right angle between them. The groove (1100) can store grease and guide grease to the tooth area (112). In the tooth region (112), the wall thickness of the flexible cylinder (11) corresponding to the tooth root of the flexible tooth (12) is D; In the non-tooth region (111), the flexible cylinder (11) includes a first section, a second section, a third section and a fourth section distributed in sequence. The first section is close to the tooth region (112), and the fourth section is close to the transition angle of the cap edge (13). The wall thickness of the first section is D1, the wall thickness of the second section is D2, the wall thickness of the third section is D3, and the wall thickness of the fourth section is D4, wherein: D≥D4, D1=D2>D3>D4; The grooves (1100) are distributed in the first segment, the second segment and the third segment. The grooves (1100) in the first segment have an opening depth of d1, the grooves (1100) in the second segment have an opening depth of d2, and the grooves (1100) in the third segment have an opening depth of d3, where D4 > d1 = d2 > d3.

2. The flexible wheel according to claim 1, characterized in that, The acute angle between the first twill (1101) and the second twill (1102) is θ, where 20°≤θ≤40°.

3. The flexible wheel according to claim 1, characterized in that, The acute angle between the first twill (1101) and the axis of the flexible cylinder (11) is α, 60°≤α≤80°; The acute angle between the second twill (1102) and the axis of the flexible cylinder (11) is β, 60°≤β≤80°.

4. The flexible wheel according to any one of claims 1-3, characterized in that, In the axial direction of the flexible cylinder (11), the distance between two adjacent first diagonal lines (1101) is H1, and the distance between two adjacent second diagonal lines (1102) is H2, where H1=H2.

5. The flexible wheel according to claim 1, characterized in that, d2=d1=a×D1, 0.3≤a≤0.35; d3 = b × D3, 0.2 ≤ b ≤ 0.

25.

6. A harmonic reducer, characterized in that, It includes a wave generator, a rigid wheel (2), and a flexible wheel (1) as described in any one of claims 1-5, wherein the wave generator is fitted inside the flexible wheel (1), and the flexible wheel (1) is fitted inside the rigid wheel (2) and meshes with the rigid wheel (2).

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