CN212690710U

CN212690710U - Internal gearing transmission mechanism

Info

Publication number: CN212690710U
Application number: CN202020176163.6U
Authority: CN
Inventors: 范正富; 陈宇昊
Original assignee: Ningbo Hansheng Transmission Technology Co ltd
Current assignee: Ningbo Hansheng Transmission Technology Co ltd
Priority date: 2019-09-12
Filing date: 2020-02-17
Publication date: 2021-03-12
Anticipated expiration: 2030-02-17
Also published as: CN112483607A

Abstract

The application discloses inner gearing drive mechanism, it includes foreign steamer and interior wheel. Be equipped with the foreign steamer internal tooth on the inward flange of foreign steamer, every foreign steamer internal tooth includes foreign steamer internal tooth addendum and foreign steamer internal tooth waist. The outer edge of the inner wheel is provided with inner wheel outer teeth, and each inner wheel outer tooth comprises an inner wheel outer tooth crest and an inner wheel outer tooth waist. The inner wheel and the outer wheel form inner meshing transmission through meshing of the outer tooth waist of the inner wheel and the inner tooth waist of the outer wheel. The outer ring internal tooth flanks and the inner ring external tooth flanks are curved surfaces having the same shape and overlapping each other, and the inner ring external teeth can mesh with the outer ring internal teeth at any time when the outer ring and the inner ring are in mesh transmission. The outer tooth waist of the inner wheel and the inner tooth waist of the outer wheel form surface contact type meshing, and the contact area of the outer tooth waist of the inner wheel and the inner tooth waist of the outer wheel gradually increases to the maximum value along with the rotation of the inner wheel and then gradually decreases. The application discloses inner gearing drive mechanism can reduce the stress concentration when interior wheel meshes with the foreign steamer, promotes the life-span of tooth.

Description

Internal gearing transmission mechanism

Technical Field

The present application relates to transmissions, and more particularly to an inter-meshing transmission.

Background

The existing internal gearing transmission mechanism mainly comprises planetary gear transmission, harmonic transmission, cycloidal pin gear transmission and the like. The planetary gear transmission mainly adopts involute gear engagement, interference can be avoided when the difference in the number of teeth between outer wheel inner teeth and inner wheel outer teeth is large, and the single-stage transmission speed ratio is small. The harmonic transmission also adopts involute gear engagement, so that one-tooth difference or two-tooth difference engagement can be realized, but a flexible gear is required to be adopted as outer teeth of an inner wheel. The problem of interference can be solved through the deformation of interior wheel external tooth, and the bearing capacity of flexbile gear is little, and shock resistance is little for the harmonic transmission is difficult to the wide use. The cycloid transmission mainly adopts a cycloid wheel as an inner wheel, one-tooth-difference internal meshing can be realized through the meshing between a cycloid contour on the cycloid wheel and a roller pin on the outer wheel, but the friction between the cycloid wheel and the roller pin can be reduced only by adopting a sliding sleeve bearing on each roller pin. The tooth-shaped meshing in all the transmissions is line contact meshing, the tooth surface contact stress is large during meshing, abrasion or tooth surface falling is easy to generate, and meanwhile, the tooth surface bearing capacity is small.

SUMMERY OF THE UTILITY MODEL

The application provides an inner gearing transmission mechanism, which comprises an outer wheel and an inner wheel. The inner edge of the outer wheel is provided with a first number of inner teeth of the outer wheel. Each the outer wheel internal tooth includes outer wheel internal tooth crest and about the outer wheel internal tooth flank of outer wheel internal tooth crest symmetry, outer wheel internal tooth flank includes meshing portion. And the outer edge of the inner wheel is provided with a second number of outer teeth of the inner wheel. Each of the inner wheel external teeth includes an inner wheel external tooth crest and an inner wheel external tooth waist symmetrical about the inner wheel external tooth crest, the inner wheel external tooth waist including a meshing portion. The first number is greater than the second number. Wherein the inner wheel is arranged in the outer wheel and rotates eccentrically relative to the outer wheel, and the inner wheel and the outer wheel form inner meshing transmission through meshing of meshing parts of outer gear tooth waists of the inner wheel and meshing parts of inner gear tooth waists of the outer wheel. Wherein the meshing portion of the outer wheel internal tooth flank and the meshing portion of the inner wheel external tooth flank are curved surfaces having the same shape and overlapping, and the outer wheel internal tooth flank and the inner wheel external tooth flank are designed such that: at any time when the outer wheel is in meshing transmission with the inner wheel, at least one inner wheel external tooth of the inner wheel external teeth can be meshed with the outer wheel internal teeth, and for each inner wheel external tooth meshed with the outer wheel internal teeth, at least one inner wheel external tooth waist and at least one outer wheel internal tooth waist can be meshed in a surface contact mode along with eccentric rotation of the inner wheel, and contact areas formed when the inner wheel external tooth waists are in contact with the outer wheel internal tooth waists can be gradually increased, and then gradually reduced and gradually separated.

The present application provides a novel tooth profile mesh, the meshing between interior wheel external tooth and the outer wheel internal tooth is the face contact meshing. The transmission principle is completely different from the traditional involute tooth profile contact meshing transmission principle, one-tooth-difference internal meshing transmission can be realized, and the single-stage transmission speed ratio is large. Because the meshing between interior wheel external tooth and the outer wheel internal tooth is the face contact meshing, consequently can make the transmission of internal gearing drive mechanism steady, the noise is low, tooth face stress is little, long-lived, shock resistance is strong.

Other features, advantages, and embodiments of the application may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Furthermore, it is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation without limiting the scope of the application as claimed. However, the detailed description and the specific examples merely indicate preferred embodiments of the application. Various changes and modifications within the spirit and scope of the application will become apparent to those skilled in the art from this detailed description.

Drawings

The features and advantages of the present application may be better understood by reading the following detailed description with reference to the drawings, in which like characters represent like parts throughout the drawings, wherein:

FIG. 1A is a schematic illustration in partial cutaway of an internal gearing mechanism according to an embodiment of the present application;

FIG. 1B is an axial cross-sectional schematic view of the internal gearing mechanism shown in FIG. 1A;

FIG. 2 is a schematic view of the engagement of the outer wheel with the inner wheel shown in FIG. 1A;

FIG. 3 is a schematic structural view of the outer wheel shown in FIG. 2;

FIG. 4 is a schematic structural view of the inner wheel shown in FIG. 2;

FIG. 5A is a schematic view showing the outer wheel internal teeth and inner wheel external teeth in an unmeshed state;

5B-5D are schematic views showing the outer wheel internal teeth and inner wheel external teeth in a partially meshed state during entry into mesh;

FIG. 5E is a schematic view showing inner wheel external teeth fully meshed with outer wheel internal teeth;

FIGS. 5F-5H are schematic views showing the inner wheel external teeth partially meshing with the outer wheel internal teeth during disengagement;

FIG. 5I is a schematic view showing the outer wheel internal teeth and the inner wheel external teeth in an unmeshed state;

FIG. 6A is an enlarged view of a first specific example of the outer wheel and the inner wheel shown in FIG. 2;

FIG. 6B is a schematic view of the outer wheel shown in FIG. 6A;

FIG. 6C is a schematic view of the inner wheel shown in FIG. 6A;

FIG. 6D is an enlarged view of the meshing section in a radial section of the outer wheel in the first specific product example shown in FIG. 6A;

FIG. 7A is an enlarged view of a second specific product example of the outer wheel and the inner wheel shown in FIG. 2;

FIG. 7B is a schematic view of the outer wheel shown in FIG. 7A;

FIG. 7C is a schematic view of the inner wheel shown in FIG. 7A;

FIG. 7D is an enlarged view of the meshing section in radial section of the outer wheel in the second specific product example shown in FIG. 7A;

FIG. 8A is an enlarged view of a third specific example of the outer wheel and the inner wheel shown in FIG. 2;

FIG. 8B is a schematic view of the outer wheel shown in FIG. 8A;

FIG. 8C is a schematic view of the inner wheel shown in FIG. 8A;

FIG. 8D is an enlarged view of the meshing section in a radial section of the outer wheel in the third specific product example shown in FIG. 8A;

FIG. 9A is an enlarged view of a fourth specific product example of the outer wheel and the inner wheel shown in FIG. 2;

FIG. 9B is a schematic view of the outer wheel shown in FIG. 9A;

FIG. 9C is a schematic view of the inner wheel shown in FIG. 9A;

fig. 9D is an enlarged view of an engaging section in a radial section of the outer wheel in the fourth concrete example shown in fig. 9A.

Detailed Description

Various embodiments of the present application will now be described with reference to the accompanying drawings, which form a part hereof. It should be understood that although directional terms, such as "left", "right", "inner" and "outer", are used herein to describe various example structural portions and elements of the present application, these terms are used herein for convenience of description only and are to be determined based on example orientations shown in the accompanying drawings. Because the embodiments disclosed herein can be arranged in a variety of orientations, these directional terms are used for purposes of illustration only and are not to be construed as limiting. In the following drawings, like parts are given like reference numerals and similar parts are given like reference numerals.

Ordinal terms such as "first" and "second" are used herein only for distinguishing and identifying, and do not have any other meanings, unless otherwise specified, either by indicating a particular sequence or by indicating a particular relationship. For example, the term "first flange body" does not itself imply the presence of "second flange body", nor does the term "second flange body" itself imply the presence of "first flange body".

Fig. 1A is a partially cut-away schematic view of an internal gearing mechanism 100 according to an embodiment of the present application, and fig. 1B is an axial cross-sectional schematic view of the internal gearing mechanism 100 shown in fig. 1A, illustrating a specific structure of each component in the internal gearing mechanism 100. As shown in FIGS. 1A-1B, the internal gear transmission 100 includes an outer wheel 102, a planet carrier 101, four inner wheels 121,122,123,124 arranged side by side, and an eccentric shaft 112. The planet carrier 101, the four inner discs 121,122,123,124 arranged side by side and the eccentric shaft 112 are all arranged inside the outer wheel 102.

In particular, the eccentric shaft 112 is a hollow shaft having a central axis X. Four eccentric portions 132,134,136,138 are provided on the outer circumference of the eccentric shaft 112. Wherein the

eccentric portions

132 and 138 are one set of eccentric sections having the same eccentric direction, the

eccentric portions

134 and 136 are the other set of eccentric sections having the same eccentric direction, and the eccentric directions of the two sets of eccentric sections are different by 180 °. The four inner wheels 121,122,123 and 124 are respectively sleeved on the four eccentric parts 132,134,136 and 138 of the eccentric shaft 112 to form four inner wheels which are arranged in parallel, so that the four inner wheels 121,122,123 and 124 can generate translation relative to the central axis X.

The outer edges of the four inner disks 121,122,123,124 are provided with inner wheel external teeth which mesh with outer wheel internal teeth provided on the inner edge of the outer wheel 102. When the eccentric shaft 112 drives the four inner wheels 121,122,123 and 124 to translate and the outer wheel 102 is fixed, the outer teeth of the inner wheels are meshed with the inner teeth of the outer wheel 102, so that the inner wheels 121,122,123 and 124 rotate while translating. In this way, the inner wheels 121,122,123,124 are able to perform eccentric rotations (i.e., rotations while translating). In other words, when the inner wheels 121,122,123,124 are eccentrically rotated, central axes (not shown) of the inner wheels 121,122,123,124 can be rotated about the central axis X.

The carrier 101 includes a first flange body 104, a second flange body 106, a connecting member 109, and a transmission member 108. Four inner discs 121,122,123,124 are supported by the planet carrier 101 and clamped in the planet carrier 101. The first flange body 104 and the second flange body 106 are disposed on both sides of the inner wheels 121,122,123,124, respectively. The first flange body 104 and the second flange body 106 are rigidly connected together by a connecting member 109 to retain the four inner discs 121,122,123,124 between the first flange body 104 and the second flange body 106. The transmission member 108 extends through the holes in the four inner disks 121,122,123,124 and connects the first flange body 104 and the second flange body 106. The transmission member 108 is capable of transmitting the movement of the inner wheels 121,122,123,124 to the first and

second flange bodies

104, 106, thereby causing the first and

second flange bodies

104, 106 to rotate. It should be noted that, since the first flange body 104 and the second flange body 106 are mounted on the outer wheel 102 through bearings, the transmission member 108 drives the first flange body 104 and the second flange body 106 to rotate around the central axis X, without causing the first flange body 104 and the second flange body 106 to translate.

The internal gearing transmission mechanism 100 of the present application can achieve the purpose of speed reduction or speed increase. When it is desired to achieve deceleration, the four inner wheels 121,122,123,124 move at high speed, while the outer wheel 102 or the planet carrier 101 moves at low speed. When the outer wheel 102 is used as a torque output member (i.e., connected with a driven member), the carrier 101 must be fixed. When the carrier 101 serves as a torque output member, the outer wheel 102 must be fixed. When the speed increase is needed, the outer wheel 102 or the planet carrier 101 moves at a low speed, and the four inner wheels 121,122,123 and 124 move at a high speed as torque output components. For convenience of description, the four inner wheels 121,122,123,124 are moved at a high speed, the outer wheel 102 is stationary, and the carrier 101 is moved at a low speed as a torque output member, and the power transmission relationship is as follows:

the eccentric shaft 112 in the internal gear transmission 100 is connected to a drive mechanism (not shown). The driving mechanism drives the eccentric shaft 112 to rotate. Because the outer wheel 102 is fixed, and because of the meshing relationship between the inner teeth of the outer wheel 102 and the outer teeth of the inner wheels 121,122,123,124, the rotation of the eccentric shaft 112 can drive the inner wheels 121,122,123,124 sleeved thereon to translate and rotate. The transmission member 108 transmits the rotation and torque of the inner wheels 121,122,123,124 to the first flange body 104 and the second flange body 106, and drives the first flange body 104 and the second flange body 106 to rotate. The first and

second flange bodies

104 and 106 are connected with a driven device (not shown) to realize speed change and torque output.

Since the four inner wheels 121,122,123,124 are similar in structure, the following describes the structural relationship between the outer teeth of the inner wheel 121 and the inner teeth of the outer wheel 102, taking the inner wheel 121 as an example:

fig. 2 is a schematic view showing the engagement between the outer wheel 102 and the inner wheel 121 shown in fig. 1A. As shown in fig. 2, the outer wheel 102 has a central axis O. The central axis O is arranged coaxially with the central axis X of the eccentric shaft 112. The inner wheel 121 is eccentrically arranged in the outer wheel 102. Specifically, the inner wheel 121 has a central axis N1. The center axis N1 is arranged in parallel with the center axis O of the outer wheel 102 and at a distance e. Wherein the eccentricity e is greater than zero (see the enlarged view of the dashed box a). A first number of outer wheel inner teeth 300 are provided on the inner edge of the outer wheel 102. A second number of inner wheel external teeth 400 are provided on the outer edge of the inner wheel 121. Wherein the first number is greater than the second number.

Fig. 3 is a schematic structural view of the outer wheel 102 shown in fig. 2. As shown in fig. 3, outer wheel 102 is a spur gear. A first number of outer wheel inner teeth 300 are disposed around the inner edge of outer wheel 102. The structure of each of the outer teeth 300 is the same. Adjacent two outer wheel inner teeth 300 are connected to each other by an outer wheel inner tooth bottom 322.

Each outer wheel inner teeth 300 includes an outer wheel inner teeth tip 302 and two outer wheel inner teeth flanks 314, 316. In a radial cross section of the outer wheel 102, the outer wheel internal tooth crest 302 is a smooth curve or straight line. The two outer wheel inner tooth flanks 314,316 are located on either side of the outer wheel inner tooth tip 302 and are symmetrically disposed about the outer wheel inner tooth tip 302 and are identical and identical. Specifically, the outer-wheel inner-tooth waist 314 is located on the left side of the outer-wheel inner-tooth crest 302, and the outer-wheel inner-tooth waist 316 is located on the right side of the outer-wheel inner-tooth crest 302.

For the left outer wheel inner tooth flank 314, the outer wheel inner tooth flank 314 is made up of a mesh section 336 (i.e., a mesh portion 336), a transition section 332, and a transition section 334. Wherein the meshing section 336 is capable of making surface contact with the inner wheel external teeth 400 during meshing. The transition section 332 is used to connect the meshing section 336 with the outer wheel inner tooth bottom 322. The transition section 334 is used to connect the meshing section 336 to the outer wheel and inner tooth crest 302. In a radial cross section of the outer wheel 102, the

transition sections

332 and 334 are a smooth curve or straight line, the meshing section 336 is a smooth curve, and the direction of the curve of the meshing section 336 is convex outward toward the teeth. In other words, the curved direction of the engagement section 336 is convex toward the center axis O of the outer wheel 102. The outer wheel inner tooth waists 314 are configured such that when the outer wheel 102 is engaged with the inner wheel 121, the

transition sections

332 and 334 are not in contact with the inner wheel 121.

Similarly, for the outer wheel inner tooth flank 316 on the right, the outer wheel inner tooth flank 316 is made up of a mesh section 346 (i.e., mesh 346), a transition section 342, and a transition section 344. Wherein the meshing section 346 is capable of making surface contact with the inner wheel external teeth 400 during meshing. The transition section 342 is used to connect the meshing section 346 to the outer wheel inner tooth bottom 322. The transition section 344 is used to connect the meshing section 346 to the outer and inner gear addendum 302. In a radial cross section of the outer wheel 102, the

transition sections

342 and 344 are a smooth curve or straight line, the meshing section 346 is a smooth curve, and the direction of the curve of the meshing section 346 is convex outward toward the teeth. In other words, the curved direction of the engagement section 346 is convex toward the center axis O of the outer wheel 102. The outer wheel inner tooth waists 316 are configured such that when the outer wheel 102 is engaged with the inner wheel 121, the

transition sections

342 and 344 are not in contact with the inner wheel 121.

A recess 355 is formed between adjacent outer wheel internal teeth 300 and outer wheel internal teeth 300 for receiving inner wheel external teeth 400. More specifically, the concave portion 355 is formed between the outer ring internal tooth flank 316 and the outer ring internal tooth flank 322 of the outer ring internal tooth 300 and the outer ring internal tooth flank 314 of the adjacent outer ring internal tooth 300. The outer wheel inner tooth flank 316 and the outer wheel inner tooth flank 314 on both sides of the recess 355 are symmetrical with respect to the outer wheel inner tooth center line X. The outer wheel inner tooth centerline X of each recess 355 passes through the center axis O of the outer wheel 102 and the midpoint of the outer wheel inner tooth bottom 322 forming the recess 355. The meshing relationship of the outer wheel internal teeth 300 and the inner wheel external teeth 400 will be described in detail below.

Fig. 4 is a schematic structural view of the inner wheel 121 shown in fig. 2. As shown in fig. 4, the inner wheel 121 is also a spur gear. A second number of inner wheel outer teeth 400 are disposed around the outer edge of the inner wheel 121. The structure of each inner wheel outer tooth 400 is the same. Adjacent two inner wheel outer teeth 400 are interconnected by an inner wheel outer teeth bottom 422.

Each inner wheel outer teeth 400 includes an inner wheel outer teeth tip 402 and two inner wheel

outer teeth waists

414, 416. On the radial section of the inner wheel 121, the outer tooth crest 402 of the inner wheel is a smooth curved surface or a straight line. The two inner wheel outer tooth flanks 414,416 are located on either side of the inner wheel outer tooth crest 402 and are symmetrically disposed about the inner wheel outer tooth crest 402 and are identical and identical symmetrically. Specifically, inner wheel outer tooth flank 414 is located to the left of inner wheel outer tooth crest 402, and inner wheel outer tooth flank 416 is located to the right of inner wheel outer tooth crest 402.

For the inner wheel outer cog belt 414 on the left, the inner wheel outer cog belt 414 is made up of a meshing section 436 (i.e., meshing portion 436), a transition section 432, and a transition section 434. Wherein the meshing section 436 is capable of making surface contact with the outer wheel internal teeth 300 during meshing. The transition section 432 is used to connect the meshing section 436 with the inner wheel outer tooth bottom 422. The transition section 434 is used to connect the meshing section 436 with the inner wheel external teeth crests 402. In a radial cross section of the outer wheel 102, the

transition sections

432 and 434 are a smooth curve or straight line, the meshing section 436 is a smooth curve, and the curve direction of the meshing section 436 is recessed toward the inside of the teeth. In other words, the curved direction of the engagement section 436 is recessed toward the central axis N1 of the inner wheel 121. The curved surface shape of the engagement section 436 is identical to and overlaps the curved surface shape of the engagement section 346. In other words, the curved shape of engagement section 436 and the curved shape of engagement section 346 can be complementary. The inner wheel outer cog belt 414 is configured such that when the outer wheel 102 is engaged with the inner wheel 121, the

transition sections

432 and 434 are not in contact with the outer wheel 102.

Similarly, for the right inner wheel outer tooth flank 416, the inner wheel outer tooth flank 416 is comprised of a meshing section 446 (i.e., meshing portion 446), a transition section 442, and a transition section 444. Wherein the meshing section 446 is capable of making surface contact with the outer wheel internal teeth 300 during meshing. The transition section 442 is used to connect the meshing section 446 with the inner wheel outer tooth bottom 422. The transition section 444 is used to connect the meshing section 446 with the inner wheel external teeth crests 402. In a radial cross section of the outer wheel 102, the

transition sections

442 and 444 are a smooth curve or straight line, the meshing section 446 is a smooth curve, and the curve direction of the meshing section 446 is recessed toward the inside of the teeth. In other words, the curvilinear direction of the engagement section 446 is concave toward the central axis N1 of the inner wheel 121. The curved surface shape of the engagement section 446 is identical to and overlaps the curved surface shape of the engagement section 336. In other words, the curved shape of the engagement section 446 and the curved shape of the engagement section 336 can be complementary. The inner wheel outer cog belt 416 is configured such that when the outer wheel 102 is engaged with the inner wheel 121, the transition segment 442 and the transition segment 444 are not in contact with the outer wheel 102. Wherein the inner wheel outer tooth flank 414 and the inner wheel outer tooth flank 416 of each inner wheel outer tooth 400 are symmetrical about the inner wheel outer tooth centerline Y. The inner race outer tooth center line Y passes through the center axis N1 of the inner race 121 and the midpoint of the inner race outer tooth crest 402.

It should be noted that the meshing section 336, the meshing section 346, the meshing section 436, and the meshing section 446 of the present application are not involute curves in a radial cross section of the outer wheel 102.

The engagement state of the outer wheel 102 and the inner wheel 121 will be described below with reference to fig. 2 to 4. Specifically, when the inner wheel 121 moves relative to the outer wheel 102, that is, the inner wheel 121 rotates eccentrically (translates and rotates) in the outer wheel 102, the meshing state of the inner wheel external teeth 400 of the inner wheel 121 with the outer wheel internal teeth 300 of the outer wheel 102 includes a partially meshing state and a fully meshing state. The outer ring inner teeth 400 of any one of the inner rings 121 are in a completely meshed state when the outer ring inner teeth center line X and the inner ring outer teeth center line Y overlap. And the inner wheel outer teeth 400 are in a partially engaged state before and after the fully engaged state. The change from the unengaged state (or disengaged state), to the partially engaged state, to the fully engaged state, and to the partially engaged state to the unengaged state (i.e., disengaged state) for the inner wheel outer teeth 400 of any one of the inner wheels 121 will be described in detail in fig. 5A-5I.

In the present application, at least one of the inner ring external teeth 400 meshes with the outer ring internal teeth 300 at any one time between the outer ring 102 and the inner ring 121. As an example, the outer wheel 102 and the inner wheel 121 are designed to: at any one time, only one inner ring outer teeth 400 are engaged with the outer ring inner teeth 300, and the other inner ring outer teeth 400 are not engaged with the outer ring inner teeth 300. As another example, the outer wheel 102 and the inner wheel 121 are designed to: at any one time, three adjacent inner ring outer teeth 400 are engaged with the outer ring inner teeth 300, and the other inner ring outer teeth 400 are not engaged with the outer ring inner teeth 300.

Fig. 5A to 5I are views illustrating the engagement and disengagement process of the inner wheel external teeth 400 of the inner wheel 121 and the outer wheel internal teeth 300 from the non-engaged state (or disengaged state), to the partially engaged state, to the fully engaged state, and to the partially engaged state to the non-engaged state (or disengaged state). During the meshing process shown in fig. 5A-5I, inner wheel external teeth 400 and outer wheel internal teeth 300 are brought into relative motion. In this embodiment, the outer wheel inner teeth 300 remain stationary and the inner wheel rotates eccentrically (i.e., translates in a clockwise direction while rotating in a counter-clockwise direction) within the outer wheel 102 in a clockwise direction (as indicated by the arrow in fig. 5A). It will be understood by those skilled in the art that fig. 5A-5I are intended to depict the process of the inner wheel outer teeth 400 of the inner wheel 121 progressively contacting the outer wheel inner teeth 300, progressively increasing contact portions, fully meshing, then progressively decreasing contact portions until separation, as can be observed during relatively high speed rotation of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 using high speed photographic techniques. It should be noted that this process is a continuous process, and in this specification, for convenience of description, the contact portion of this dynamically continuous process is specifically described by being divided into different time periods. As will be understood by those skilled in the art, fig. 5A-5I are cross-sectional views of the inner wheel external teeth 400 and the outer wheel internal teeth 300 in the radial direction. The line contact of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is indicated by schematic point contact in a cross-sectional view in the radial direction, and the surface contact of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is indicated by schematic line contact in a cross-sectional view in the radial direction.

Fig. 5A shows a schematic view of the outer wheel internal teeth 300 and the inner wheel external teeth 400 in an unengaged state (i.e., disengaged or separated from each other). As can be seen in fig. 5A, the outer wheel internal teeth 300 are not in contact with the inner wheel external teeth 400. More specifically, neither the meshing section 436 of the inner wheel outer tooth flank 414 nor the meshing section 446 of the inner wheel outer tooth flank 416 is in contact with the meshing section 346 of the outer wheel inner tooth flank 316 and the meshing section 336 of the outer wheel inner tooth flank 314.

Fig. 5B-5D are schematic views showing the outer wheel internal teeth 300 and the inner wheel external teeth 400 in a partially meshed state during entering into meshing engagement. In the case of the inner wheel external teeth waist 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal teeth waist 316 on the left side of the outer wheel internal teeth 300, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction in the process from the state shown in fig. 5A to the state shown in fig. 5B, the distance between the meshing section 436 and the meshing section 346 gradually decreases compared to the state shown in fig. 5A, but the inner wheel external teeth waist 414 is not yet in contact with the outer wheel internal teeth waist 316 on the left side of the outer wheel internal teeth 300.

In the course of the state shown in fig. 5A to the state shown in fig. 5B, the meshing section 446 gradually approaches the meshing section 336 with respect to the inner wheel external teeth tooth waist 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal teeth tooth waist 314 on the right side of the outer wheel internal teeth 300 until the meshing section 446 starts to form a contact portion with the meshing section 336 as shown in fig. 5B. The contact portion may be a line contact or a surface contact. More specifically, the contact portion is formed by contact between the top of the engagement section 446 and the upper portion of the engagement section 336. The projection of the contact portion on its radial cross section is shown as a contact point (or contact point) a.

In the case of the inner wheel external tooth flank 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 316 on the left side of the outer wheel internal teeth 300, the distance between the meshing section 436 and the meshing section 346 continues to gradually decrease in the process from the state shown in fig. 5B to the state shown in fig. 5C, but the meshing section 436 is not yet in contact with the meshing section 346. The engagement section 436 in the state shown in fig. 5C is closer to the engagement section 346 than in the state shown in fig. 5B.

In the course from the state shown in fig. 5B to the state shown in fig. 5C, the contact area of the contact portion between the meshing section 446 and the meshing section 336 gradually increases for the inner wheel external tooth flank 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right side of the outer wheel internal teeth 300. In the state shown in fig. 5C, the projection of the contact portion of the engagement section 446 and the engagement section 336 on the radial section thereof is a line segment B-C. More specifically, in the process from fig. 5B to 5C, the contact portion between the engagement section 446 and the engagement section 336 gradually increases, and may be an increase in contact area, or may be changed from line contact to surface contact. And this surface contact is not caused by the forced deformation between the gears, but is achieved by the engagement section 446 and the engagement section 336 being configured with curved surfaces that are identical in shape and that coincide. During the process that the contact portion (or area) of the engagement section 446 with the engagement section 336 is gradually increased, the inner wheel outer teeth 400 are moved upward with respect to the outer wheel inner teeth 300, so that the engagement section 446 is moved upward with respect to the engagement section 336. At this point, the contact point (or point of contact) B is located generally at the top of the engagement section 446 and above the engagement section 336, but is located closer to the outer wheel inner tooth bottom 322 than the previous contact point (or point of contact) a shown in fig. 5B on the engagement section 336.

As for the inner wheel external teeth waist 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal teeth waist 316 on the left side of the outer wheel internal teeth 300, in the process from the state shown in fig. 5C to the state shown in fig. 5D, the meshing section 436 gradually approaches the meshing section 346 so that in the state shown in fig. 5D, the meshing section 436 and the meshing section 346 start to form a contact portion. More specifically, the contact is formed by contact at or about the top of the engagement section 436 with the upper portion of the engagement section 346. The projection of the contact portion on its radial cross section is shown as a contact point (or contact point) a.

In the course from the state shown in fig. 5C to the state shown in fig. 5D, the contact area of the contact portion between the meshing section 446 and the meshing section 336 continues to increase gradually for the inner wheel external tooth flank 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right side of the outer wheel internal teeth 300. In the state shown in fig. 5D, the projection of the contact surface of the engagement section 446 with the engagement section 336 on the radial section thereof is a line segment D-E. More specifically, in the process from fig. 5C to 5D, the contact area of the contact portion of the meshing section 446 with the meshing section 336 continues to gradually increase, and the inner wheel outer teeth 400 continue to move upward relative to the outer wheel inner teeth 300, so that the meshing section 446 moves upward relative to the meshing section 336. At this point, the contact point (or point) D is located generally at the top of the engagement section 446 and above the engagement section 336, but is located closer to the outer wheel inner tooth bottom 322 than the previous contact point (or point) B shown in fig. 5C on the engagement section 336.

Fig. 5E shows a schematic view of the inner wheel outer teeth 400 in a fully meshed state with the outer wheel inner teeth 300. As for the inner wheel outer tooth flank 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner tooth flank 316 on the left side of the outer wheel inner teeth 300, in the process from fig. 5D to 5E, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the contact area of the contact portion between the meshing section 436 and the meshing section 346 gradually increases. In the state shown in fig. 5E, the projection of the contact portion of the engagement section 436 with the engagement section 346 on the radial section thereof is a line segment b-c. The engagement section 436 now coincides with the engagement section 346. More specifically, in the process from the state shown in fig. 5D to the state shown in fig. 5E, the contact portion between the engagement section 436 and the engagement section 346 gradually increases, and may be an increase in contact surface or a change from line contact to surface contact. And this surface contact is not caused by the forced deformation between the gears, but is achieved by the engagement section 436 and the engagement section 346 being configured with curved surfaces that are identical in shape and that coincide. During eccentric rotation of the inner wheel outer teeth 400 with respect to the outer wheel inner teeth 300, the meshing section 436 moves upward with respect to the meshing section 346 until the contact point b is located at the top of the meshing

sections

436 and 346 and the contact point c is located at the bottom of the meshing

sections

436 and 346. At this time, the engagement section 436 coincides with (engages with) the engagement section 346.

In the course of the state shown in fig. 5D to the state shown in fig. 5E, the contact area of the contact portion between the meshing section 446 and the meshing section 336 continues to increase gradually for the inner wheel external tooth flank 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right side of the outer wheel internal teeth 300. In the state shown in fig. 5E, the projection of the contact portion of the engagement section 446 and the engagement section 336 on the radial section thereof is a line segment F-G. At this point, the engagement section 446 coincides with the engagement section 336. More specifically, during the process from the state shown in fig. 5D to the state shown in fig. 5E, the inner wheel outer teeth 400 continue to move upward relative to the outer wheel inner teeth 300 until the contact point (or contact point) F is located at the top of the meshing section 446 and the meshing section 336 and the contact point (or contact point) G is located at the bottom of the meshing section 446 and the meshing section 336. At this time, the engaging section 446 coincides with (engages with) the engaging section 336.

Thus, in the state shown in fig. 5E, when the meshing section 436 and the meshing section 346 coincide (mesh) together and the meshing section 446 and the meshing section 336 coincide (mesh) together, the outer wheel internal teeth center line X and the inner wheel external teeth center line Y coincide, and the inner wheel external teeth 400 and the outer wheel internal teeth 300 are in the completely meshed state.

Fig. 5F-5H show schematic views of inner wheel external teeth 400 partially meshed with outer wheel internal teeth 300 during disengagement. As for the inner wheel outer tooth flank 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner tooth flank 316 on the left side of the outer wheel inner teeth 300, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction in the process shown in fig. 5E to 5F, the meshing section 436 starts to be disengaged from the lower portion of the meshing section 346, so that the contact area of the contact portion between the inner wheel outer tooth flank 414 and the outer wheel inner tooth flank 316 gradually decreases. In the state shown in fig. 5F, the projection of the contact portion of the engagement section 436 with the engagement section 346 on the radial section thereof is a line segment d-e. More specifically, in the process shown in fig. 5E to 5F, the inner wheel outer teeth 400 move downward relative to the outer wheel inner teeth 300, thereby causing the meshing section 436 to move downward relative to the meshing section 346. At this time, the contact point (or contact point) d is located approximately at the upper portion of the meshing section 436 and the meshing section 346, but its position on the meshing section 346 is farther from the outer ring inner tooth bottom 322 than the previous contact point (or contact point) b shown in fig. 5E. The contact location (or point) E is located approximately midway between the meshing

sections

436 and 346, closer to the outer wheel inner tooth bottom 322 than the previous contact location (or point) c shown in fig. 5E.

As for the inner wheel external tooth flank 416 on the right of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right of the outer wheel internal teeth 300, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction in the process shown in fig. 5E to 5F, the meshing section 336 starts to be disengaged from the lower portion of the meshing section 446, so that the contact area of the contact portion between the meshing section 336 and the meshing section 446 gradually decreases. In the state shown in fig. 5F, the projection of the contact portion of the engagement section 336 with the engagement section 446 on a radial section thereof is a line segment H-I. More specifically, in the process shown in fig. 5E to 5F, the inner wheel outer teeth 400 move downward relative to the outer wheel inner teeth 300, thereby causing the meshing section 446 to move downward relative to the meshing section 336. At this time, the contact point (or contact point) H is located approximately at the upper portion of the meshing section 336 and the meshing section 446, but its position on the meshing section 446 is farther from the outer wheel inner tooth bottom 322 than the previous contact point (or contact G) shown in fig. 5E. The contact point I is located generally below the meshing

sections

336 and 446, closer to the outer wheel inner tooth bottom 322 than the previous contact point G shown in fig. 5E.

It should also be noted that as the inner wheel continues to rotate eccentrically in the clockwise direction within the outer wheel 102, the degree of disengagement between the engagement section 436 and the engagement section 346 is greater than the degree of disengagement between the engagement section 336 and the engagement section 446. In other words, the contact area of the contact between the engagement section 436 and the engagement section 346 is smaller than the contact area between the engagement section 336 and the engagement section 446. That is, the contact point (or contact point) e is closer to the outer ring internal tooth bottom 322 than the contact point (or contact point) I.

As for the inner wheel external teeth waist 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal teeth waist 316 on the left side of the outer wheel internal teeth 300, as the inner wheel continues to eccentrically rotate in the outer wheel 102 in the clockwise direction during the process from the state shown in fig. 5F to the state shown in fig. 5G, the meshing section 436 continues to be disengaged from the lower portion of the meshing section 346, so that the contact area of the contact portion between the meshing section 436 and the meshing section 346 gradually decreases until the contact portion is formed by contact substantially at the top of the meshing section 436 with the upper portion of the meshing section 346 as shown in fig. 5G. The projection of this contact portion (or contact line) on its radial cross section is shown as contact point (or contact point) f.

As for the inner wheel external tooth flank 416 on the right of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right of the outer wheel internal teeth 300, as the inner wheel continues to eccentrically rotate in the outer wheel 102 in the clockwise direction during the process from the state shown in fig. 5F to the state shown in fig. 5G, the meshing section 336 continues to be disengaged from the lower portion of the meshing section 446, so that the contact area of the contact portion between the meshing section 336 and the meshing section 446 continues to gradually decrease. In the state shown in fig. 5G, the projection of the contact portion of the engagement section 336 and the engagement section 446 on the radial section thereof is a line segment J-K. More specifically, in the process shown in fig. 5F to 5G, the inner wheel outer teeth 400 move downward relative to the outer wheel inner teeth 300, thereby causing the meshing section 446 to move downward relative to the meshing section 336. At this time, the contact point J is located approximately at the upper portion of the meshing section 336 and the meshing section 446, but its position on the meshing section 336 is farther from the outer ring inner tooth bottom 322 than the previous contact point H shown in fig. 5F. The contact point K is located generally below the meshing section 336 and the meshing section 446, but is located closer to the outer wheel inner tooth bottom 322 than the previous contact point I shown in fig. 5F on the meshing section 336.

As for the inner wheel external teeth waist 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal teeth waist 316 on the left side of the outer wheel internal teeth 300, as the inner wheel continues to eccentrically rotate in the outer wheel 102 in the clockwise direction during the process from the state shown in fig. 5G to the state shown in fig. 5H, the meshing section 436 continues to be disengaged from the lower portion of the meshing section 346 until the meshing section 436 and the meshing section 346 do not contact each other as shown in fig. 5H.

As for the inner wheel external teeth tooth waist 416 to the right of the inner wheel external teeth 400 and the outer wheel internal teeth tooth waist 314 to the right of the outer wheel internal teeth 300, as the inner wheel continues to eccentrically rotate in the outer wheel 102 in the clockwise direction in the process from the state shown in fig. 5G to the state shown in fig. 5H, the meshing section 336 continues to be disengaged from the lower portion of the meshing section 446. More specifically, the contact portion is formed by contact between the engagement section 336 and an upper portion of the engagement section 446. The projection of the contact on its radial cross section is shown as the contact location (or point) L.

Fig. 5I shows a schematic view of the outer wheel internal teeth 300 and the inner wheel external teeth 400 in an unmeshed state (i.e., disengaged from each other). As for the inner wheel external teeth tooth waist 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal teeth tooth waist 316 on the left side of the outer wheel internal teeth 300, as the inner wheel continues to eccentrically rotate in the outer wheel 102 in the clockwise direction in the process from the state shown in fig. 5H to the state shown in fig. 5I, the meshing section 436 remains out of contact with the meshing section 346, and the distance between the meshing section 436 and the meshing section 346 gradually increases. During the process from the state shown in fig. 5H to the state shown in fig. 5I, for the inner wheel external teeth waist 416 to the right of the inner wheel external teeth 400 and the outer wheel internal teeth waist 314 to the right of the outer wheel internal teeth 300, as the inner wheel continues to rotate eccentrically in the clockwise direction in the outer wheel 102, the meshing section 336 is completely disengaged (not in contact) with the meshing section 446.

Thus, as can be seen from the above-described meshing process, in the process from the start of meshing to the fully meshed state, the contact area of the contact portion of the inner wheel external tooth flank 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 316 on the left side of the outer wheel internal teeth 300 and the contact area of the contact portion of the inner wheel external tooth flank 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right side of the outer wheel internal teeth 300 gradually increase in the radial cross-sectional projection (see fig. 5A to 5E) until the fully meshed state reaches the maximum value (see fig. 5E). In the process from the fully engaged state to the disengaged state, the projection of the contact area of the contact portion of the inner wheel external tooth flank 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 316 on the left side of the outer wheel internal teeth 300 and the contact portion of the inner wheel external tooth flank 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right side of the outer wheel internal teeth 300 on the radial cross section gradually decreases from the maximum value (see fig. 5E to 5I).

Further, in the process from the start of meshing to the fully meshed state, and from the fully meshed state to the disengagement, the inner wheel external tooth flank 414 on the left side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 316 on the left side of the outer wheel internal teeth 300, and the inner wheel external tooth flank 416 on the right side of the inner wheel external teeth 400 and the outer wheel internal tooth flank 314 on the right side of the outer wheel internal teeth 300 are each configured to: the contact area at the contact portion gradually increases and then gradually decreases.

In the present application, the term "surface contact" means that, when the inner ring external teeth 400 and the outer ring internal teeth 300 are in a completely meshed state, the length of the contact line between the inner ring external tooth flank 414 and the outer ring internal tooth flank 316 is at least 1% greater than the length of the inner ring external tooth flank 414, and the length of the contact line between the inner ring external tooth flank 416 and the outer ring internal tooth flank 314 is at least 1% greater than the length of the inner ring external tooth flank 416, in a radial cross section of the inner ring external teeth 400 and the outer ring internal teeth 300. In other words, the length of the

engagement segments

436 and 446 of the inner wheel 121 is at least 1% greater than the length of the inner wheel external tooth flanks 414 and 416, respectively.

Although fig. 5A to 5I show a specific positional relationship between one inner wheel outer teeth 400 and one outer wheel inner teeth 300 from an unmeshed state to a completely shed state and to an unmeshed state, it will be understood by those skilled in the art that the inner wheel outer teeth 400 in the inner wheel 121 and the outer wheel inner teeth 300 in the outer wheel 102 can be sequentially meshed during eccentric rotation of the inner wheel 121 by 360 ° in the outer wheel 102, and any one of the inner wheel outer teeth 400 in the inner wheel 121 can be meshed with the outer wheel inner teeth 300.

In a conventional internal gear transmission, the external teeth of the inner wheel and the internal teeth of the outer wheel are usually engaged by using the cycloid and the needle roller or the involute and the involute, so that the external teeth of the inner wheel and the internal teeth of the outer wheel are engaged in a line contact manner. The contact area of the line contact engagement is very small, nearly zero. When the inner wheel outer teeth and the outer wheel inner teeth are driven, since the area of the line meshing is almost zero, the tooth surface stress generated when the inner wheel outer teeth and the outer wheel inner teeth are meshed is very large. The extreme stress causes the surface of the gear to peel off, the service life of the external teeth of the inner wheel and the internal teeth of the outer wheel is short, and the transmission of the internal-meshing transmission mechanism is not smooth enough.

In the internal gear transmission mechanism 100 of the present invention, the inner ring external teeth and the outer ring internal teeth can be surface-meshed. The contact area of the surface mesh is much larger than that of the wire mesh in the conventional internal-meshing transmission. As an example, the length of the contact line of the surface mesh of the internal gear transmission mechanism 100 of the present application is 0.1mm in the radial cross section of the internal gear external teeth and the external gear internal teeth. If the length of the contact line of the wire mesh in the conventional internal gear mechanism has a certain length, for example, 0.001mm in the calculation of stress (the tooth surface contact area cannot be set to zero in the calculation of stress, otherwise the tooth surface stress will be infinite), the line contact length of the present application will be 100 times the contact length of the wire mesh. Thus, the stress between the inner ring outer teeth and the outer ring inner teeth of the surface mesh of the present application is 0.01 times the stress between the inner ring outer teeth and the outer ring inner teeth of the conventional wire mesh. This can greatly reduce the stress between the outer teeth of the inner ring and the inner teeth of the outer ring, thereby avoiding the occurrence of wear, breakage, and the like of the gears. This also enables the heat generated by the external teeth of the inner wheel and the internal teeth of the outer wheel due to stress to be reduced, thereby making the stability of the internal gearing mechanism 100 better and the service life longer. As an example, the lubricating oil in the speed reducer manufactured by using the internal gear transmission mechanism of the present application maintains its original color after operating at 1500rpm for 1000 hours under a rated load, whereas the lubricating oil in the speed reducer is blackened after operating the speed reducer of the conventional internal gear transmission mechanism under the same operating conditions. This demonstrates that the surface contact meshing between the inner wheel external teeth and the outer wheel internal teeth of the present application, with less tooth flank stress and less heat generation and wear than the prior art using meshing transmissions between cycloids and needles or involutes and involutes.

The term "overlap" in the description of the present application that "the meshing portions of the outer ring internal tooth flanks and the meshing portions of the inner ring external tooth flanks have curved surfaces that have the same shape and overlap" includes both complete overlap (i.e., the meshing portions and the meshing portions are 100% overlapped) and substantial overlap. The difference between substantial and complete registration is: substantial registration is caused by precision errors due to manufacturing, machining, assembly, etc. Those skilled in the art will appreciate that such precision errors caused by manufacturing, machining, assembly, etc. do not affect the engagement portions and the engagement portions coming into surface contact, and that the precision errors do not affect the internal meshing transmission mechanism of the present application to achieve the technical effects described above.

Fig. 6A is an enlarged view of a first concrete example of the outer wheel 102 and the inner wheel 121 shown in fig. 2 to show a mating state of the outer wheel 102 and the inner wheel 121; FIG. 6B is a schematic view of the outer wheel 102 shown in FIG. 6A; FIG. 6C is a schematic view of the inner wheel 121 shown in FIG. 6A; fig. 6D is an enlarged view of the engaging section 336 in the radial section of the outer wheel 102 in the first concrete example shown in fig. 6A. In fig. 6A-6D, fig. 6A-6C are shown in 1: the enlarged view drawn to the scale of 30 shows a first specific example of the outer wheel 102 and the inner wheel 121 shown in fig. 2. In this first specific example, the number of teeth of the outer wheel 102 is 36 and the number of teeth of the inner wheel 121 is 35, that is, the difference in the number of teeth between the outer wheel 102 and the inner wheel 121 is 1 (i.e., one tooth difference). The eccentricity e between the outer wheel 102 and the inner wheel 121 is 2 mm. The modulus of the teeth is 2.4 mm. The tooth top height of the inner ring external teeth 400 and the outer ring internal teeth 300 is 2.4 mm. Fig. 6D plots a specific curve of the engagement segment 336 in a radial cross-section of the outer wheel 102 on a scale of 1: 1500.

Fig. 7A is an enlarged view of a second concrete example of the outer wheel 102 and the inner wheel 121 shown in fig. 2 to show a state where the outer wheel 102 and the inner wheel 121 are fitted; FIG. 7B is a schematic view of the outer wheel 102 shown in FIG. 7A; FIG. 7C is a schematic view of the inner wheel 121 shown in FIG. 7A; fig. 7D is an enlarged view of the engaging section 336 in the radial section of the outer wheel 102 in the second concrete example shown in fig. 7A. In fig. 7A-7D, fig. 7A-7C are illustrated with 1: the enlarged view drawn on the scale of 30 shows a second specific example of the outer wheel 102 and the inner wheel 121 shown in fig. 2. In this second specific example, the number of teeth of the outer wheel 102 is 60 and the number of teeth of the inner wheel 121 is 59, that is, the difference in the number of teeth between the outer wheel 102 and the inner wheel 121 is 1 (i.e., one tooth difference). The eccentricity e between the outer wheel 102 and the inner wheel 121 is 1.2 mm. The modulus of the teeth is 1.4 mm. The tooth top height of the inner ring external teeth 400 and the outer ring internal teeth 300 is 1.5 mm. Fig. 7D plots a specific curve of the meshing section 336 on a radial section of the outer wheel 102 on a scale of 1: 2400.

Fig. 8A is an enlarged view of a third concrete example of the outer wheel 102 and the inner wheel 121 shown in fig. 2 to show a fitted state of the outer wheel 102 and the inner wheel 121; FIG. 8B is a schematic view of the outer wheel 102 shown in FIG. 8A; FIG. 8C is a schematic view of the inner wheel 121 shown in FIG. 8A; fig. 8D is an enlarged view of the engaging section 336 in the radial section of the outer wheel 102 in the third concrete example shown in fig. 8A. In fig. 8A-8D, fig. 8A-8C are shown in a 1: an enlarged view on the scale of 30 shows a third specific example of the outer wheel 102 and the inner wheel 121 shown in fig. 2. In this third specific example, the number of teeth of the outer wheel 102 is 100, and the number of teeth of the inner wheel 121 is 98, that is, the difference in the number of teeth between the outer wheel 102 and the inner wheel 121 is 2 (i.e., two teeth difference). The eccentricity e between the outer wheel 102 and the inner wheel 121 is 2.0 mm. The modulus of the teeth is 2.0 mm. The tooth top height of the inner ring external teeth 400 and the outer ring internal teeth 300 is 2.0 mm. Fig. 8D plots a specific curve of the engagement segment 336 on a radial cross-section of the outer wheel 102 on a scale of 1: 3000.

Fig. 9A is an enlarged view of a fourth concrete example of the outer wheel 102 and the inner wheel 121 shown in fig. 2 to show a fitted state of the outer wheel 102 and the inner wheel 121; FIG. 9B is a schematic view of the outer wheel 102 shown in FIG. 9A; FIG. 9C is a schematic view of the inner wheel 121 shown in FIG. 9A; fig. 9D is an enlarged view of the engaging section 336 in the radial section of the outer wheel 102 in the fourth concrete example shown in fig. 9A. Fig. 9A-9C are performed at 1: the enlarged scale drawing of scale 50 shows a fourth specific example of the outer wheel 102 and the inner wheel 121 shown in fig. 2. In this fourth specific example, the number of teeth of the outer wheel 102 is 72 and the number of teeth of the inner wheel 121 is 69, that is, the difference in the number of teeth between the outer wheel 102 and the inner wheel 121 is 3 (i.e., three teeth difference). The eccentricity e between the outer wheel 102 and the inner wheel 121 is 2.3 mm. The modulus of the teeth is 1.0 mm. The tooth top height of the inner ring external teeth 400 and the outer ring internal teeth 300 is 0.6 mm. Fig. 9D plots a specific curve of the engagement section 336 in a radial cross section of the outer wheel 102 on a scale of 1: 4000.

While only certain features of the application have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the application.

Claims

1. An internal gearing transmission (100), comprising:

an outer wheel (102), a first number of outer wheel inner teeth (300) being provided on an inner edge of the outer wheel (102), each outer wheel inner tooth (300) comprising an outer wheel inner tooth crest (302) and an outer wheel inner tooth flank being symmetrical about the outer wheel inner tooth crest (302), the outer wheel inner tooth flank comprising a meshing portion; and

an inner wheel having a second number of inner wheel external teeth (400) on an outer edge thereof, each inner wheel external teeth (400) including inner wheel external teeth crests (402) and inner wheel external teeth waists symmetrical about the inner wheel external teeth crests (402), the inner wheel external teeth waists including meshing portions, the first number being greater than the second number;

wherein the inner wheel is arranged in the outer wheel (102) and rotates eccentrically relative to the outer wheel (102), and the inner wheel and the outer wheel (102) form internal meshing transmission through meshing of meshing parts of external gear tooth flanks of the inner wheel and meshing parts of internal gear tooth flanks of the outer wheel;

wherein the meshing portion of the outer wheel internal tooth flank and the meshing portion of the inner wheel external tooth flank are curved surfaces having the same shape and overlapping, and the outer wheel internal tooth flank and the inner wheel external tooth flank are designed such that: when the outer wheel (102) is in meshing transmission with the inner wheel, at least one inner wheel external tooth (400) of the inner wheel external teeth (400) can be meshed with the outer wheel internal teeth (300), and for each inner wheel external tooth (400) meshed with the outer wheel internal teeth (300), at least one inner wheel external tooth waist and the outer wheel internal tooth waist can be in surface contact type meshing with each other along with eccentric rotation of the inner wheel.

2. An internal gearing mechanism (100) as claimed in claim 1, wherein:

as the inner ring rotates eccentrically, the contact area formed when the inner ring external tooth flanks contact the outer ring internal tooth flanks changes.

3. An internal gearing mechanism (100) as claimed in claim 2, wherein:

along with the eccentric rotation of the inner wheel, the contact area formed when the outer gear tooth waist of the inner wheel is in contact with the inner gear tooth waist of the outer wheel can be gradually increased, and then the contact area is gradually reduced and gradually separated.

4. An internal gearing mechanism (100) as claimed in claim 3, wherein:

the outer wheel inner tooth flank and the inner wheel outer tooth flank are designed such that: for each of the inner wheel external teeth (400) that mesh with the outer wheel internal teeth (300), both of the inner wheel external tooth flanks of the inner wheel external teeth (400) mesh with outer wheel internal tooth flanks of the outer wheel internal teeth (300), and the meshing is a surface-contact meshing.

5. Internal gearing (100) according to claim 4, characterized in that:

the outer wheel inner tooth flank and the inner wheel outer tooth flank are designed such that: for each of the inner wheel external teeth (400) that mesh with the outer wheel internal teeth (300), a meshing portion of the inner wheel external tooth waist and a meshing portion of the outer wheel internal tooth waist have a partially meshed state and a fully meshed state;

when the meshing portion of the inner ring external tooth flank and the meshing portion of the outer ring internal tooth flank are in the partial meshing state, a part of the meshing portion of the inner ring external tooth flank can be in surface contact meshing with a part of the meshing portion of the outer ring internal tooth flank;

when the meshing portion of the inner wheel external tooth flank and the meshing portion of the outer wheel internal tooth flank are in the complete meshing state, the meshing portion of the outer wheel internal tooth flank can have the largest contact area with the meshing portion of the inner wheel external tooth flank;

wherein the inner ring external tooth flanks and the outer ring internal tooth flanks are brought into the partially meshed state when the meshing portions of the inner ring external tooth flanks and the meshing portions of the outer ring internal tooth flanks start to mesh or disengage.

6. An internal gearing mechanism (100) as claimed in claim 5, wherein:

when the meshing portion of the inner wheel external tooth flank and the meshing portion of the outer wheel internal tooth flank are meshed from the beginning to the complete meshing state, the contact area between the meshing portion of the inner wheel external tooth flank and the meshing portion of the outer wheel internal tooth flank is gradually increased;

when the meshing portion of the inner ring external tooth flank and the meshing portion of the outer ring internal tooth flank are disengaged from the fully meshed state, the contact area between the meshing portion of the inner ring external tooth flank and the meshing portion of the outer ring internal tooth flank is gradually reduced.

7. An internal gearing mechanism (100) as claimed in claim 6, wherein:

meshing parts of inner wheel external tooth tops on two sides of the inner wheel external tooth tops (402) are symmetrically arranged around an inner wheel external tooth center line (Y);

the meshing parts of the tooth waists of the outer wheel inner teeth (300) and the meshing parts of the tooth waists of the outer wheel inner teeth (300) adjacent to each other are symmetrically arranged around an outer wheel inner tooth central line (X);

when the inner wheel is meshed with the outer wheel (102) and the inner wheel external teeth center line (Y) coincides with the outer wheel internal teeth center line (X), the inner wheel external teeth (400) and the outer wheel internal teeth (300) are in the completely meshed state.

8. An internal gearing mechanism (100) as claimed in claim 6, wherein:

the outer wheel inner teeth (300) and the inner wheel outer teeth (400) are straight gears;

wherein, on the radial section of the inner wheel and the outer wheel (102), the outer wheel internal tooth waist and the inner wheel external tooth waist are continuously smooth curves, the curved direction of the meshing part of the outer wheel internal tooth waist is convex towards the outside of the teeth of the outer wheel internal teeth (300), and the curved direction of the meshing part of the inner wheel external tooth waist is concave towards the inside of the teeth of the inner wheel external teeth (400).

9. An internal gearing mechanism (100) as claimed in claim 1, wherein:

the difference between the first number and the second number is 1.

10. An internal gearing mechanism (100) as claimed in claim 7, wherein:

when the meshing portion of the inner wheel external tooth flank and the meshing portion of the outer wheel internal tooth flank are in the complete meshing state, the length of a contact line between the meshing portion of the inner wheel external tooth flank and the meshing portion of the outer wheel internal tooth flank is greater than 1% of the length of the inner wheel external tooth flank on the cross section of the outer wheel internal teeth (300) and the outer wheel external teeth (400).

11. An internal gearing mechanism (100) as claimed in claim 8, wherein:

in a radial cross section of the inner ring and the outer ring (102), a curve of a meshing portion of outer tooth flanks of the inner ring and a curve of a meshing portion of inner tooth flanks of the outer ring are not involute curves.