Internal gear transmission

Abstract

The present application discloses an internal meshing transmission mechanism, which includes an outer wheel and an inner wheel. The inner edge of the outer wheel is provided with outer wheel inner teeth, and each outer wheel inner tooth includes an outer wheel inner tooth top and an outer wheel inner tooth waist. The outer edge of the inner wheel is provided with inner wheel outer teeth, and each inner wheel outer tooth includes an inner wheel outer tooth top and an inner wheel outer tooth waist. The inner wheel and the outer wheel form an internal meshing transmission through the meshing of the inner wheel outer tooth waist and the outer wheel inner tooth waist. The outer wheel inner tooth waist and the inner wheel outer tooth waist are curved surfaces with the same shape and overlap, and at any time when the outer wheel and the inner wheel are meshed, the inner wheel outer teeth can mesh with the outer wheel inner teeth. The inner wheel outer tooth waist and the outer wheel inner tooth waist form a surface contact meshing, and the contact area between the inner wheel outer tooth waist and the outer wheel inner tooth waist gradually increases to a maximum value as the inner wheel rotates, and then gradually decreases. The internal meshing transmission mechanism of the present application can reduce stress concentration when the inner wheel and the outer wheel are meshed, and improve the life of the teeth.

Description

Technical Field

[0001] The present application relates to a transmission mechanism, and more particularly to an internal meshing transmission mechanism. Background Art

[0002] The existing internal meshing transmission mechanisms mainly include planetary gear transmission, harmonic transmission and cycloidal pinwheel transmission. Among them, the planetary gear transmission mainly adopts involute gear meshing. The difference in the number of teeth between the inner teeth of the outer wheel and the outer teeth of the inner wheel can avoid interference, and the single-stage transmission speed ratio is small. Harmonic transmission also adopts involute gear meshing, which can achieve one-tooth difference or two-tooth difference meshing, but it is necessary to use a flexible wheel as the outer teeth of the inner wheel. The interference problem can only be solved by the deformation of the outer teeth of the inner wheel. The flexible wheel has a small load-bearing capacity and low impact resistance, making it difficult for harmonic transmission to be widely used. The cycloidal transmission mainly adopts the cycloidal wheel as the inner wheel. Through the meshing between the cycloidal profile on the cycloidal wheel and the needle roller on the outer wheel, a one-tooth difference internal meshing can be achieved, but each needle roller must be equipped with a sleeve bearing to reduce the friction between the cycloidal wheel and the needle roller. The tooth meshing in all the above transmissions is line contact meshing. The contact stress of the tooth surface is large during meshing, which is easy to cause wear or tooth surface shedding, and the tooth surface load-bearing capacity is small. Summary of the invention

[0003] The present application provides an internal meshing transmission mechanism, which includes an outer wheel and an inner wheel. A first number of outer wheel inner teeth are provided on the inner edge of the outer wheel. Each of the outer wheel inner teeth includes an outer wheel inner tooth top and an outer wheel inner tooth waist symmetrical with respect to the outer wheel inner tooth top, and the outer wheel inner tooth waist includes a meshing portion. A second number of inner wheel outer teeth are provided on the outer edge of the inner wheel. Each of the inner wheel outer teeth includes an inner wheel outer tooth top and an inner wheel outer tooth waist symmetrical with respect to the inner wheel outer tooth top, and the inner wheel outer tooth waist includes a meshing portion. The first number is greater than the second number. Wherein, the inner wheel is arranged inside the outer wheel and rotates eccentrically relative to the outer wheel, and the inner wheel and the outer wheel form an internal meshing transmission through the meshing of the meshing portion of the inner wheel outer tooth waist with the meshing portion of the outer wheel inner tooth waist. Among them, the meshing portion of the outer wheel inner tooth waist and the meshing portion of the inner wheel outer tooth waist are curved surfaces with the same shape and overlap, and the outer wheel inner tooth waist and the inner wheel outer tooth waist are designed as follows: at any time when the outer wheel and the inner wheel are meshingly transmitted, at least one of the inner wheel outer teeth can mesh with the outer wheel inner teeth, and for each of the inner wheel outer teeth meshing with the outer wheel inner teeth, as the inner wheel rotates eccentrically, at least one of the inner wheel outer teeth waist and the outer wheel inner teeth waist can form a surface contact meshing, and the contact area formed when the inner wheel outer teeth waist and the outer wheel inner teeth waist contact can gradually increase, then transition to gradually decrease, and gradually separate.

[0004] The present application provides a new tooth profile meshing, in which the meshing between the inner wheel outer teeth and the outer wheel inner teeth is surface contact meshing. It is completely different from the transmission principle of the traditional involute tooth profile line contact meshing, and can realize a one-tooth difference internal meshing transmission, and a single-stage transmission speed ratio is large. Since the meshing between the inner wheel outer teeth and the outer wheel inner teeth is surface contact meshing, the internal meshing transmission mechanism can achieve smooth transmission, low noise, small tooth surface stress, long service life, and strong impact resistance.

[0005] By considering the following specific embodiments, drawings and claims, other features, advantages and embodiments of the present application can be set forth or become apparent. In addition, it should be understood that the above-mentioned summary of the invention and the following specific embodiments are exemplary and are intended to provide further explanations without limiting the scope of the present application for protection. However, the specific embodiments and specific examples only indicate preferred embodiments of the present application. For those skilled in the art, various changes and modifications within the spirit and scope of the present application will become apparent through the specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The features and advantages of the present application may be better understood by reading the following detailed description with reference to the accompanying drawings, in which like reference numerals refer to like parts throughout, wherein:

[0007] Figure 1A A partially cutaway schematic diagram of an internal meshing transmission mechanism according to an embodiment of the present application;

[0008] Figure 1B for Figure 1A An axial cross-sectional schematic diagram of an internal meshing transmission mechanism is shown;

[0009] Figure 2 for Figure 1A Schematic diagram of the meshing of the outer wheel and the inner wheel shown;

[0010] Figure 3 for Figure 2 The schematic diagram of the structure of the outer wheel shown;

[0011] Figure 4 for Figure 2 The structural schematic diagram of the inner wheel shown;

[0012] Figure 5A A schematic diagram showing the outer wheel inner teeth and the inner wheel outer teeth in a non-meshing state;

[0013] Figures 5B-5D A schematic diagram showing the inner teeth of the outer wheel and the outer teeth of the inner wheel being in a partially meshed state during the process of entering into meshing;

[0014] Figure 5E A schematic diagram showing the inner wheel outer teeth and the outer wheel inner teeth in a fully meshed state;

[0015] Figure 5F-5H A schematic diagram showing the inner wheel outer teeth and the outer wheel inner teeth being in a partially meshed state during the process of disengagement;

[0016] Fig.5I A schematic diagram showing the outer wheel inner teeth and the inner wheel outer teeth in a non-meshing state;

[0017] Fig. 6A for Figure 2 An enlarged view of a first specific product example of an outer wheel and an inner wheel is shown;

[0018] Figure 6B for Figure 2 An enlarged view of a second specific product example of an outer wheel and an inner wheel is shown;

[0019] Figure 6C for Figure 2 An enlarged view of a third specific product example of the outer wheel and the inner wheel shown;

[0020] Fig.6D for Figure 2 An enlarged view of a fourth specific product example of the outer wheel and the inner wheel is shown. DETAILED DESCRIPTION

[0021] Various specific embodiments of the present application will be described below with reference to the accompanying drawings that form a part of this specification. It should be understood that although terms indicating directions are used in this application, such as "left", "right", "inside" and "outside" and other directions or orientations to describe various example structural parts and elements of the present application, these terms are used here only for the purpose of convenience of explanation and are determined based on the example orientations shown in the accompanying drawings. Since the embodiments disclosed in the present application can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. In the following drawings, the same figure numbers are used for the same parts and similar figure numbers are used for similar parts.

[0022] Ordinal numbers such as "first" and "second" used in this application are only used for distinction and identification, and do not have any other meanings. If not specifically specified, they do not indicate a specific order or have a specific association. For example, the term "first flange body" itself does not imply the existence of a "second flange body", and the term "second flange body" itself does not imply the existence of a "first flange body".

[0023] Figure 1A FIG. 1 is a partial cross-sectional schematic diagram of an internal meshing transmission mechanism 100 according to an embodiment of the present application. Figure 1B for Figure 1AThe axial cross-sectional view of the internal meshing transmission mechanism 100 is shown to illustrate the specific structure of each component in the internal meshing transmission mechanism 100. Figure 1A-1B As shown, the internal gear transmission mechanism 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 wheels 121, 122, 123, 124 arranged side by side, and the eccentric shaft 112 are all arranged inside the outer wheel 102.

[0024] Specifically, the eccentric shaft 112 is a hollow shaft with a central axis X. Four eccentric parts 132, 134, 136, 138 are arranged on the outer circumference of the eccentric shaft 112. The eccentric parts 132 and 138 are a group of eccentric segments with the same eccentric direction, and the eccentric parts 134 and 136 are another group of eccentric segments with the same eccentric direction, and the eccentric directions of the two groups of eccentric segments differ by 180°. The four inner wheels 121, 122, 123, 124 are respectively sleeved on the four eccentric parts 132, 134, 136, 138 of the eccentric shaft 112 to form four inner wheels arranged in parallel, so that the four inner wheels 121, 122, 123, 124 can generate translation relative to the central axis X.

[0025] The outer edges of the four inner wheels 121, 122, 123, 124 are provided with inner wheel outer teeth, which mesh with the outer wheel inner teeth provided on the inner edge of the outer wheel 102. When the eccentric shaft 112 drives the four inner wheels 121, 122, 123, 124 to translate and the outer wheel 102 is fixed, the inner wheel outer teeth mesh with the outer wheel inner teeth of the outer wheel 102, so that the inner wheels 121, 122, 123, 124 translate and rotate at the same time. In this way, the inner wheels 121, 122, 123, 124 can achieve eccentric rotation (that is, rotate while translating). In other words, when the inner wheels 121, 122, 123, 124 rotate eccentrically, the central axis (not shown) of the inner wheels 121, 122, 123, 124 can rotate around the central axis X.

[0026] The planet carrier 101 includes a first flange body 104, a second flange body 106, a connecting component 109 and a transmission component 108. The four inner wheels 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 arranged 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 the connecting component 109 to hold the four inner wheels 121, 122, 123, 124 between the first flange body 104 and the second flange body 106. The transmission component 108 passes through the holes on the four inner wheels 121, 122, 123, 124 and connects the first flange body 104 and the second flange body 106. The transmission component 108 can transmit the movement of the inner wheels 121, 122, 123, 124 to the first flange body 104 and the second flange body 106, so that the first flange body 104 and the second flange body 106 rotate. It should be noted that since the first flange body 104 and the second flange body 106 are installed on the outer wheel 102 through bearings, the transmission component 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 move in translation.

[0027] The internal meshing transmission mechanism 100 of the present application can achieve the purpose of deceleration or acceleration. When deceleration is required, the four inner wheels 121, 122, 123, 124 move at high speed, while the outer wheel 102 or the planetary carrier 101 moves at low speed. When the outer wheel 102 is used as a torque output component (i.e., connected to the driven component), the planetary carrier 101 must be fixed. When the planetary carrier 101 is used as a torque output component, the outer wheel 102 must be fixed. When acceleration is required, the outer wheel 102 or the planetary carrier 101 moves at low speed, and the four inner wheels 121, 122, 123, 124 move at high speed as the torque output component. For ease of description, the following description will be based on the example of the four inner wheels 121, 122, 123, 124 moving at high speed, the outer wheel 102 being fixed, and the planetary carrier 101 moving at low speed as the torque output component, and its power transmission relationship is roughly as described as follows:

[0028] The eccentric shaft 112 in the internal meshing transmission mechanism 100 is connected to a driving mechanism (not shown). The driving mechanism drives the eccentric shaft 112 to rotate. Since the outer wheel 102 is fixed and the outer teeth of the outer wheel 102 are meshed with 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 mounted thereon to translate and rotate. The transmission component 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 flange body 104 and the second flange body 106 are connected to a driven device (not shown), thereby achieving speed change and torque output.

[0029] Since the structures of the four inner wheels 121, 122, 123, and 124 are similar, the structural relationship between the inner wheel outer teeth of the inner wheel 121 and the outer wheel inner teeth of the outer wheel 102 is described below by taking the inner wheel 121 as an example:

[0030] Figure 2 for Figure 1A The schematic diagram of the meshing of the outer wheel 102 and the inner wheel 121 is shown in FIG. Figure 2 As shown, the outer wheel 102 has a center axis O. The center axis O is coaxially arranged with the center 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 center axis N1. The center axis N1 is arranged parallel to the center axis O of the outer wheel 102, and the distance is e. The eccentricity e is greater than zero (see the enlarged view of the dotted 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 outer teeth 400 are provided on the outer edge of the inner wheel 121. The first number is greater than the second number.

[0031] Figure 3 for Figure 2 The schematic diagram of the structure of the outer wheel 102 is shown in FIG. Figure 3 As shown, the outer wheel 102 is a spur gear. A first number of outer wheel inner teeth 300 are arranged around the inner edge of the outer wheel 102. The structure of each outer wheel inner tooth 300 is the same. Two adjacent outer wheel inner teeth 300 are connected to each other by the outer wheel inner tooth bottom 322.

[0032] Each outer wheel inner tooth 300 includes an outer wheel inner tooth top 302 and two outer wheel inner tooth waists 314, 316. On the radial cross section of the outer wheel 102, the outer wheel inner tooth top 302 is a smooth curve or a straight line. The two outer wheel inner tooth waists 314, 316 are respectively located on both sides of the outer wheel inner tooth top 302, and are symmetrically arranged about the outer wheel inner tooth top 302, and are completely symmetrical and identical. Specifically, the outer wheel inner tooth waist 314 is located on the left side of the outer wheel inner tooth top 302, and the outer wheel inner tooth waist 316 is located on the right side of the outer wheel inner tooth top 302.

[0033] For the outer wheel inner gear waist 314 on the left side, the outer wheel inner gear waist 314 is composed of a meshing section 336 (i.e., meshing portion 336), a transition section 332, and a transition section 334. The meshing section 336 can form a surface contact with the inner wheel outer gear 400 during the meshing process. The transition section 332 is used to connect the meshing section 336 with the outer wheel inner gear bottom 322. The transition section 334 is used to connect the meshing section 336 with the outer wheel inner gear top 302. On the radial cross section of the outer wheel 102, the transition section 332 and the transition section 334 are a smooth curve or a straight line, the meshing section 336 is a smooth curve, and the curve direction of the meshing section 336 protrudes toward the outside of the tooth. In other words, the curve direction of the meshing section 336 protrudes toward the central axis O of the outer wheel 102. The outer wheel inner teeth waist 314 is configured such that when the outer wheel 102 is meshed with the inner wheel 121 , the transition sections 332 and 334 do not contact the inner wheel 121 .

[0034] Similarly, for the outer wheel inner gear waist 316 on the right side, the outer wheel inner gear waist 316 is composed of a meshing section 346 (i.e., meshing portion 346), a transition section 342, and a transition section 344. The meshing section 346 can form a surface contact with the inner wheel outer gear 400 during the meshing process. The transition section 342 is used to connect the meshing section 346 with the outer wheel inner gear bottom 322. The transition section 344 is used to connect the meshing section 346 with the outer wheel inner gear top 302. On the radial cross section of the outer wheel 102, the transition section 342 and the transition section 344 are a smooth curve or a straight line, the meshing section 346 is a smooth curve, and the curve direction of the meshing section 346 protrudes toward the outside of the tooth. In other words, the curve direction of the meshing section 346 protrudes toward the central axis O of the outer wheel 102. The outer wheel inner teeth waist 316 is configured such that when the outer wheel 102 is meshed with the inner wheel 121 , the transition sections 342 and 344 do not contact the inner wheel 121 .

[0035] A recess 355 is formed between adjacent outer wheel inner teeth 300 for receiving the inner wheel outer teeth 400. More specifically, a recess 355 is formed between the outer wheel inner teeth waist 316 and the outer wheel inner teeth bottom 322 of the outer wheel inner teeth 300 and the outer wheel inner teeth waist 314 of the adjacent outer wheel inner teeth 300. The outer wheel inner teeth waist 316 and the outer wheel inner teeth waist 314 on both sides of the recess 355 are symmetrical about the outer wheel inner teeth center line X. The outer wheel inner teeth center line X of each recess 355 passes through the center axis O of the outer wheel 102 and the midpoint of the outer wheel inner teeth bottom 322 forming the recess 355. The meshing relationship between the outer wheel inner teeth 300 and the inner wheel outer teeth 400 will be described in detail below.

[0036] Figure 4 for Figure 2 The schematic diagram of the structure of the inner wheel 121 is shown in FIG. Figure 4 As shown, the inner wheel 121 is also a spur gear. A second number of inner wheel outer teeth 400 are arranged around the outer edge of the inner wheel 121. The structure of each inner wheel outer tooth 400 is the same. Two adjacent inner wheel outer teeth 400 are connected to each other by the inner wheel outer tooth bottom 422.

[0037] Each inner wheel outer tooth 400 includes an inner wheel outer tooth top 402 and two inner wheel outer tooth waists 414, 416. On the radial cross section of the inner wheel 121, the inner wheel outer tooth top 402 is a smooth curved surface or a straight line. The two inner wheel outer tooth waists 414, 416 are respectively located on both sides of the inner wheel outer tooth top 402, and are symmetrically arranged about the inner wheel outer tooth top 402, and are completely symmetrical and identical. Specifically, the inner wheel outer tooth waist 414 is located on the left side of the inner wheel outer tooth top 402, and the inner wheel outer tooth waist 416 is located on the right side of the inner wheel outer tooth top 402.

[0038] For the inner wheel outer tooth waist 414 on the left side, the inner wheel outer tooth waist 414 is composed of a meshing section 436 (i.e., meshing portion 436), a transition section 432 and a transition section 434. The meshing section 436 can form a surface contact with the outer wheel inner tooth 300 during the meshing process. 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 outer tooth top 402. On the radial cross section of the outer wheel 102, the transition sections 432 and 434 are a smooth curve or a straight line, the meshing section 436 is a smooth curve, and the curve direction of the meshing section 436 is concave toward the inner teeth. In other words, the curve direction of the meshing section 436 is concave toward the central axis N1 of the inner wheel 121. In addition, the curved surface shape of the meshing section 436 is the same as and coincides with the curved surface shape of the meshing section 346. In other words, the curved surface shape of the meshing section 436 is complementary to the curved surface shape of the meshing section 346. The inner wheel outer teeth waist 414 is configured such that when the outer wheel 102 meshes with the inner wheel 121, the transition section 432 and the transition section 434 do not contact the outer wheel 102.

[0039] Similarly, for the inner wheel outer tooth waist 416 on the right side, the inner wheel outer tooth waist 416 is composed of a meshing section 446 (i.e., meshing portion 446), a transition section 442, and a transition section 444. The meshing section 446 can form a surface contact with the outer wheel inner tooth 300 during the meshing process. 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 outer tooth top 402. On the radial cross section of the outer wheel 102, the transition sections 442 and 444 are a smooth curve or a straight line, the meshing section 446 is a smooth curve, and the curve direction of the meshing section 446 is concave toward the inner teeth. In other words, the curve direction of the meshing section 446 is concave toward the central axis N1 of the inner wheel 121. In addition, the curved surface shape of the meshing section 446 is the same as and coincides with the curved surface shape of the meshing section 336. In other words, the curved surface shape of the meshing section 446 can complement the curved surface shape of the meshing section 336. The inner wheel outer teeth waist 416 is configured so that when the outer wheel 102 is meshed with the inner wheel 121, the transition section 442 and the transition section 444 do not contact the outer wheel 102. The inner wheel outer teeth waist 414 and the inner wheel outer teeth waist 416 of each inner wheel outer tooth 400 are symmetrical about the inner wheel outer teeth center line Y. The inner wheel outer teeth center line Y passes through the center axis N1 of the inner wheel 121 and the midpoint of the inner wheel outer teeth top 402.

[0040] It should be noted that, on the radial cross section of the outer wheel 102 , the meshing segments 336 , 346 , 436 and 446 of the present application are not involutes.

[0041] Combine the following Figure 2-Figure 4 To describe the meshing state of the outer wheel 102 and the inner wheel 121. Specifically, when the inner wheel 121 moves relative to the outer wheel 102, that is, when the inner wheel 121 rotates eccentrically (translationally and rotationally) in the outer wheel 102, the meshing state of the inner wheel outer teeth 400 of the inner wheel 121 and the outer wheel inner teeth 300 of the outer wheel 102 includes a partial meshing state and a full meshing state. For any inner wheel outer teeth 400 of the inner wheel 121, it is in a full meshing state when the center line X of the outer wheel inner teeth coincides with the center line Y of the inner wheel outer teeth. Before and after the full meshing state, the inner wheel outer teeth 400 are in a partial meshing state. For any inner wheel outer teeth 400 of the inner wheel 121, the changes from an unmeshed state (or a disengaged state), to a partially meshed state, to a fully meshed state, and then to a partially meshed state to an unmeshed state (i.e., a disengaged state) will be described in Figures 5A-5I Described in detail.

[0042] It should also be noted that, in the present application, at any time, at least one inner wheel outer tooth 400 of the outer wheel 102 and the inner wheel 121 is meshed with the outer wheel inner tooth 300. As an example, the outer wheel 102 and the inner wheel 121 are designed such that at any time, only one inner wheel outer tooth 400 is meshed with the outer wheel inner tooth 300, and the other inner wheel outer teeth 400 are not meshed with the outer wheel inner teeth 300. As another example, the outer wheel 102 and the inner wheel 121 are designed such that at any time, three adjacent inner wheel outer teeth 400 are meshed with the outer wheel inner teeth 300, and the other inner wheel outer teeth 400 are not meshed with the outer wheel inner teeth 300.

[0043] Combine the following Figures 5A-5I The meshing and disengagement process diagram of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 of the inner wheel 121 starts from a non-meshing state (or a disengaged state), changes to a partially meshed state, changes to a fully meshed state, and then transitions to a partially meshed state to a non-meshing state (or a disengaged state). Figures 5A-5I During the meshing process shown in FIG. 1 , the inner wheel outer teeth 400 and the outer wheel inner teeth 300 form relative motion. In this embodiment, the outer wheel inner teeth 300 remain stationary, and the inner wheel moves in a clockwise direction (eg, Figure 5A The outer wheel 102 (as shown by the arrow in the middle) rotates eccentrically in the outer wheel 102 (i.e., translates in the clockwise direction and rotates in the counterclockwise direction at the same time). It should be understood by those skilled in the art that Figures 5A-5I The process of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 gradually contacting, gradually increasing the contact area, fully meshing, then gradually decreasing the contact area, and finally separating can be observed by high-speed photography during the relative high-speed rotation of the inner wheel outer teeth 400 and the outer wheel inner teeth 300. It should be noted that this process is a continuous process. In this specification, for the convenience of description, the contact part of this dynamic continuous process is divided into different time periods for specific description. People in this field can understand that Figures 5A-5I It is a cross-sectional view of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 along the radial direction. In the cross-sectional view along the radial direction, the line contact between the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is schematically represented by point contact, while in the cross-sectional view along the radial direction, the surface contact between the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is schematically represented by line contact.

[0044] Figure 5A FIG. 2 shows a schematic diagram of the outer wheel inner teeth 300 and the inner wheel outer teeth 400 being in a non-engaged state (ie, disengaged or separated from each other). Figure 5A It can be seen that the outer wheel inner teeth 300 are not in contact with the inner wheel outer teeth 400. More specifically, the meshing section 436 of the inner wheel outer teeth waist 414 and the meshing section 446 of the inner wheel outer teeth waist 416 are not in contact with the meshing section 346 of the outer wheel inner teeth waist 316 and the meshing section 336 of the outer wheel inner teeth waist 314.

[0045] Figures 5B-5D The schematic diagram shows that the outer wheel inner teeth 300 and the inner wheel outer teeth 400 are in a partially meshed state during the process of entering meshing. For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Figure 5A In the process from the state shown in FIG5B to the state shown in FIG5B, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, compared to Figure 5A In the state shown, the distance between the meshing section 436 and the meshing section 346 gradually decreases, but the inner wheel outer teeth waist 414 still does not contact the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300 .

[0046] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Figure 5A 5B, the meshing section 446 gradually approaches the meshing section 336 until the meshing section 336 is formed. Figure 5B As shown, the meshing section 446 begins to form a contact portion with the meshing section 336. The contact portion can be a line contact or a surface contact. More specifically, the contact portion is formed by contact between the top of the meshing section 446 or approximately the top of the meshing section 446 and the upper part of the meshing section 336. The projection of the contact portion on its radial cross section is shown as a contact position (or contact point) A.

[0047] For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Figure 5B In the process from the state shown in FIG5 to the state shown in FIG5C , the distance between the meshing section 436 and the meshing section 346 continues to gradually decrease, but the meshing section 436 still does not contact the meshing section 346. Figure 5B In the state shown, the engagement segment 436 in the state shown in 5C is closer to the engagement segment 346.

[0048] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Figure 5B During the process from the state shown in FIG5A to the state shown in FIG5C, the contact area of ​​the contact portion between the meshing section 446 and the meshing section 336 gradually increases. Figure 5C In the state shown in FIG. 1 , the projection of the contact portion of the meshing segment 446 and the meshing segment 336 on the radial cross section is the line segment BC. Figures 5B to 5CIn the process shown, the gradual increase in the contact portion between the meshing segment 446 and the meshing segment 336 can be an increase in the contact surface, or it can be a change from line contact to surface contact. And this surface contact is not caused by the force deformation between the gears, but is achieved by the meshing segment 446 and the meshing segment 336 being configured as surfaces with the same shape and overlapping. In the process of the gradual increase in the contact portion (or area) between the meshing segment 446 and the meshing segment 336, the inner wheel outer teeth 400 move upward relative to the outer wheel inner teeth 300, thereby causing the meshing segment 446 to move upward relative to the meshing segment 336. At this time, the contact portion (or contact point) B is roughly located at the top of the meshing segment 446 and the upper part of the meshing segment 336, but its position on the meshing segment 336 is lower than that on the meshing segment 336. Figure 5B The previous contact position (or contact point) A shown is closer to the tooth bottom 322 of the inner teeth of the outer wheel.

[0049] For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Figure 5C 5D, the meshing section 436 gradually approaches the meshing section 346 so that in the state shown in FIG. Figure 5D In the state shown, the meshing segment 436 begins to form a contact portion with the meshing segment 346. More specifically, the contact portion is formed by contact between the top of the meshing segment 436 or substantially the top of the meshing segment 346. The projection of the contact portion on its radial cross section is shown as a contact position (or contact point) a.

[0050] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Figure 5C During the process from the state shown in FIG5A to the state shown in FIG5D , the contact area of ​​the contact portion between the meshing segment 446 and the meshing segment 336 continues to gradually increase. Figure 5D In the state shown in FIG. 1 , the projection of the contact surface of the meshing segment 446 and the meshing segment 336 on the radial cross section is the line segment DE. Figures 5C to 5D In the process shown, the contact area between the meshing section 446 and the meshing section 336 continues to gradually increase, and the inner wheel outer teeth 400 continues 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 time, the contact part (or contact point) D is roughly located at the top of the meshing section 446 and the upper part of the meshing section 336, but its position on the meshing section 336 is lower than that on the meshing section 336. Figure 5C The previous contact position (or contact point) B shown is closer to the tooth bottom 322 of the inner teeth of the outer wheel.

[0051] Figure 5ESchematic diagram showing the inner wheel outer teeth 400 and the outer wheel inner teeth 300 in a fully meshed state. For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Figures 5D to 5E In the process shown in FIG. 1 , 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 segment 436 and the meshing segment 346 gradually increases. Figure 5E In the state shown, the projection of the contact portion of the meshing segment 436 and the meshing segment 346 on the radial cross section is the line segment bc. At this time, the meshing segment 436 and the meshing segment 346 overlap. More specifically, in the Figure 5D In the process from the state shown in FIG5 to the state shown in FIG5E, the contact portion between the meshing segment 436 and the meshing segment 346 gradually increases, which can be an increase in the contact surface or a change from line contact to surface contact. And this surface contact is not caused by the force deformation between the gears, but is realized by the meshing segment 436 and the meshing segment 346 being configured with the same shape and overlapping curved surfaces. During the eccentric rotation of the inner wheel outer teeth 400 relative to the outer wheel inner teeth 300, the meshing segment 436 moves upward relative to the meshing segment 346 until the contact portion (or contact point) b is located at the top of the meshing segment 436 and the meshing segment 346, and the contact portion (or contact point) c is located at the bottom of the meshing segment 436 and the meshing segment 346. At this time, the meshing segment 436 and the meshing segment 346 overlap (mesh) together.

[0052] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Figure 5D During the process from the state shown in FIG5 to the state shown in FIG5E, the contact area of ​​the contact portion between the meshing section 446 and the meshing section 336 continues to gradually increase. Figure 5E In the state shown in FIG. 1 , the projection of the contact portion of the meshing segment 446 and the meshing segment 336 on the radial cross section is a line segment FG. At this time, the meshing segment 446 overlaps with the meshing segment 336. More specifically, in the state from Figure 5D In the process from the state shown in FIG5 to the state shown in FIG5E, the inner wheel outer teeth 400 continue to move upward relative to the outer wheel inner teeth 300 until the contact part (or contact point) F is located at the top of the meshing segment 446 and the meshing segment 336, and the contact part (or contact point) G is located at the bottom of the meshing segment 446 and the meshing segment 336. At this time, the meshing segment 446 and the meshing segment 336 overlap (mesh) together.

[0053] Therefore, in Figure 5EIn the state shown, when the meshing segment 436 overlaps (meshes) with the meshing segment 346 and the meshing segment 446 overlaps (meshes) with the meshing segment 336, the center line X of the outer wheel inner teeth overlaps with the center line Y of the inner wheel outer teeth, and the inner wheel outer teeth 400 and the outer wheel inner teeth 300 are in a fully meshed state.

[0054] Figure 5F-5H The schematic diagram shows that the inner wheel outer teeth 400 and the outer wheel inner teeth 300 are in a partially meshed state during the disengagement process. Figures 5E to 5F In the process shown, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the lower portion of the meshing section 436 and the meshing section 346 begin to disengage, so that the contact area between the inner wheel outer tooth waist 414 and the outer wheel inner tooth waist 316 gradually decreases. Fig. 5F In the state shown, the projection of the contact portion of the meshing segment 436 and the meshing segment 346 on the radial cross section is the line segment de. Figures 5E to 5F In the process shown, the inner wheel outer teeth 400 move downward relative to the outer wheel inner teeth 300, so that the meshing section 436 moves downward relative to the meshing section 346. At this time, the contact part (or contact point) d is roughly located at the upper part of the meshing section 436 and the meshing section 346, but its position on the meshing section 346 is lower than that on the meshing section 346. Figure 5E The previous contact position (or contact point) b shown is further away from the outer wheel inner gear bottom 322. The contact position (or contact point) e is approximately located in the middle of the meshing section 436 and the meshing section 346. Figure 5E The previous contact position (or contact point) c shown is closer to the tooth bottom 322 of the inner teeth of the outer wheel.

[0055] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Figures 5E to 5F In the process shown, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the lower parts of the meshing sections 336 and 446 begin to disengage, so that the contact area of ​​the contact portion between the meshing sections 336 and 446 gradually decreases. Fig. 5F In the state shown, the projection of the contact portion of the meshing segment 336 and the meshing segment 446 on the radial cross section is the line segment HI. Figures 5E to 5F In the process shown, the inner wheel outer teeth 400 move downward relative to the outer wheel inner teeth 300, so that the meshing section 446 moves downward relative to the meshing section 336. At this time, the contact part (or contact point) H is roughly located at the upper part of the meshing section 336 and the meshing section 446, but its position on the meshing section 446 is lower than that on the meshing section 446. Figure 5EThe previous contact point position (or contact G) shown is further away from the outer wheel inner gear tooth bottom 322. The contact position (or contact point) I is approximately located at the lower part of the meshing section 336 and the meshing section 446, compared to Figure 5E The previous contact position (or contact point) G shown is closer to the tooth bottom 322 of the inner teeth of the outer wheel.

[0056] It should also be noted that, since the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the degree of disengagement between the meshing section 436 and the meshing section 346 is greater than the degree of disengagement between the meshing section 336 and the meshing section 446. In other words, the contact area of ​​the contact portion between the meshing section 436 and the meshing section 346 is smaller than the contact area between the meshing section 336 and the meshing section 446. In other words, the contact portion (or contact point) e is closer to the tooth bottom 322 of the inner tooth of the outer wheel than the contact portion (or contact point) I.

[0057] For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Fig. 5F In the process from the state shown in FIG5 to the state shown in FIG5G, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the meshing section 436 and the lower part of the meshing section 346 continue to disengage, so that the contact area of ​​the contact portion between the meshing section 436 and the meshing section 346 gradually decreases until the inner wheel 102 is eccentrically rotated in the outer wheel 102 in the clockwise direction. Figure 5G As shown, the contact portion is formed by the contact between the top of the meshing segment 436 and the upper part of the meshing segment 346. The projection of the contact portion (or contact line) on its radial cross section is shown as a contact position (or contact point) f.

[0058] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Fig. 5F In the process from the state shown in FIG5 to the state shown in FIG5G, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the lower part of the meshing section 336 and the meshing section 446 continue to disengage, so that the contact area of ​​the contact portion between the meshing section 336 and the meshing section 446 continues to gradually decrease. Figure 5G In the state shown in FIG. 1 , the projection of the contact portion of the meshing segment 336 and the meshing segment 446 on the radial cross section is a line segment JK. Figures 5F to 5G In the process shown, the inner wheel outer teeth 400 move downward relative to the outer wheel inner teeth 300, so that the meshing section 446 moves downward relative to the meshing section 336. At this time, the contact part (or contact point) J is roughly located at the upper part of the meshing section 336 and the meshing section 446, but its position on the meshing section 336 is lower than that on the meshing section 336. Fig. 5FThe previous contact position (or contact point) H shown is further away from the outer wheel inner gear bottom 322. The contact position (or contact point) K is roughly located at the lower part of the meshing section 336 and the meshing section 446, but its position on the meshing section 336 is lower than that on the meshing section 446. Fig. 5F The previous contact position (or contact point) I shown is closer to the tooth bottom 322 of the inner teeth of the outer wheel.

[0059] For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Figure 5G During the process from the state shown in FIG5 to the state shown in FIG5H, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the meshing section 436 and the lower part of the meshing section 346 continue to disengage until the inner wheel 102 is eccentrically rotated in the outer wheel 102 in the clockwise direction. Figure 5H As shown, the engagement segment 436 and the engagement segment 346 do not contact each other.

[0060] For the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300, Figure 5G In the process from the state shown in FIG5 to the state shown in FIG5H, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the lower part of the meshing segment 336 and the meshing segment 446 continue to disengage. More specifically, the contact portion is formed by the contact substantially located at the upper part of the meshing segment 336 and the meshing segment 446. The projection of the contact on the radial cross section thereof is shown as a contact position (or contact point) L.

[0061] Fig.5I Schematic diagram showing the outer wheel inner teeth 300 and the inner wheel outer teeth 400 in a non-engaged state (i.e., disengaged from each other). For the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, Figure 5H During the process from the state shown in FIG5 to the state shown in FIG5I, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the meshing section 436 and the meshing section 346 remain out of contact, and the distance between the meshing section 436 and the meshing section 346 gradually increases. Figure 5H In the process from the state shown in the figure to the state shown in 5I, for the inner wheel outer tooth waist 416 on the right side of the inner wheel outer tooth 400 and the outer wheel inner tooth waist 314 on the right side of the outer wheel inner tooth 300, as the inner wheel continues to rotate eccentrically in the outer wheel 102 in the clockwise direction, the meshing section 336 is completely disengaged (not in contact) from the meshing section 446.

[0062] Therefore, it can be seen from the above meshing process that from the beginning of meshing to the fully meshing state, the contact area of ​​the contact portion between the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, and the contact area of ​​the contact portion between the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300 are gradually increased in the radial cross section (see Figures 5A-5E ) until it reaches its maximum value in the fully engaged state (see Figure 5E ). In the process from the fully meshed state to the disengaged state, the contact area of ​​the contact portion between the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, and the contact area of ​​the contact portion between the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300 are projected on the radial cross section from the maximum value (see Figure 5E-5I ).

[0063] In addition, in the process from the initial engagement to the fully engaged state, and from the fully engaged state to the disengagement, the inner wheel outer teeth waist 414 on the left side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 316 on the left side of the outer wheel inner teeth 300, as well as the inner wheel outer teeth waist 416 on the right side of the inner wheel outer teeth 400 and the outer wheel inner teeth waist 314 on the right side of the outer wheel inner teeth 300 are all configured as follows: the contact area at the contact portion gradually increases and then transitions to gradually decrease.

[0064] The surface contact mentioned in the present application means that when the inner wheel outer teeth 400 and the outer wheel inner teeth 300 are in a fully meshed state, on the radial cross section of the inner wheel outer teeth 400 and the outer wheel inner teeth 300, the length of the contact line between the inner wheel outer teeth waist 414 and the outer wheel inner teeth waist 316 is at least greater than 1% of the length of the inner wheel outer teeth waist 414, and the length of the contact line between the inner wheel outer teeth waist 416 and the outer wheel inner teeth waist 314 is at least greater than 1% of the length of the inner wheel outer teeth waist 416. In other words, the lengths of the meshing sections 436 and 446 of the inner wheel 121 are at least greater than 1% of the lengths of the inner wheel outer teeth waist 414 and the inner wheel outer teeth waist 416, respectively.

[0065] Although Figures 5A-5I Only the specific positional relationship between an inner wheel outer tooth 400 and an outer wheel inner tooth 300 from a non-meshing state to a fully meshed state and then to a non-meshing state is shown, but those skilled in the art can understand that when the inner wheel 121 rotates 360° eccentrically in the outer wheel 102, the inner wheel outer teeth 400 in the inner wheel 121 and the outer wheel inner teeth 300 in the outer wheel 102 can mesh sequentially, and any inner wheel outer teeth 400 in the inner wheel 121 will have the above-mentioned meshing process when meshing with the outer wheel inner teeth 300.

[0066] In a traditional internal meshing transmission mechanism, the outer teeth of the inner wheel and the inner teeth of the outer wheel usually use the meshing between the cycloid and the needle roller or the involute and the involute, so that the outer teeth of the inner wheel and the inner teeth of the outer wheel form a line contact meshing. The contact area of ​​the line contact meshing is very small, close to zero. When the outer teeth of the inner wheel and the inner teeth of the outer wheel are transmitting, since the area of ​​the line meshing is close to zero, the tooth surface stress generated when the outer teeth of the inner wheel and the inner teeth of the outer wheel mesh is very large. The extremely large stress will cause the gear surface to peel off, the service life of the outer teeth of the inner wheel and the inner teeth of the outer wheel is short, and the transmission of the internal meshing transmission mechanism is not smooth enough.

[0067] The inner wheel outer teeth and the outer wheel inner teeth in the internal meshing transmission mechanism 100 of the present application can form a surface meshing. The contact area of ​​the surface meshing greatly exceeds the contact area of ​​the line meshing in the traditional internal meshing transmission mechanism. As an example, on the radial section of the inner wheel outer teeth and the outer wheel inner teeth, the contact line length of the surface meshing of the internal meshing transmission mechanism 100 of the present application is 0.1mm. If the contact line length of the line meshing in the traditional internal meshing transmission mechanism has a certain length, for example, it is set to 0.001mm during stress calculation (the tooth surface contact area cannot be set to zero during stress calculation, 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 line meshing. Therefore, the stress between the inner wheel outer teeth and the outer wheel inner teeth of the surface meshing of the present application is 0.01 times the stress between the inner wheel outer teeth and the outer wheel inner teeth of the traditional line meshing. This can greatly reduce the stress between the inner wheel outer teeth and the outer wheel inner teeth, thereby avoiding wear, breakage and other conditions of the gears. This can also reduce the heat generated by stress between the inner wheel outer teeth and the outer wheel inner teeth, thereby making the internal meshing transmission mechanism 100 more stable and having a longer service life. As an example, after the reducer manufactured using the internal meshing transmission mechanism of the present application runs at a speed of 1500rpm under rated load for 1000 hours, the lubricating oil in the reducer still maintains its original color, while the lubricating oil in the reducer of the traditional internal meshing transmission mechanism will turn black after running under the same operating conditions. This shows that compared with the meshing transmission between cycloid and needle roller or involute and involute in the prior art, the surface contact meshing between the inner wheel outer teeth and the outer wheel inner teeth of the present application has small tooth surface stress, and generates less heat and wear.

[0068] It should be noted that the "overlap" in the "the meshing portion of the tooth waist of the inner teeth of the outer wheel and the meshing portion of the tooth waist of the outer teeth of the inner wheel are curved surfaces with the same shape and overlap" described in the present application includes both complete overlap (that is, the meshing portions overlap 100%) and substantial overlap. The difference between substantial overlap and complete overlap is that the substantial overlap is caused by precision errors caused by manufacturing, processing, assembly, etc. Those skilled in the art will understand that such precision errors caused by manufacturing, processing, assembly, etc. will not affect the surface contact between the meshing portions, and such precision errors will not affect the internal meshing transmission mechanism of the present application to achieve the technical effects described above.

[0069] Fig. 6A for Figure 2 An enlarged view of a first specific product example of the outer wheel 102 and the inner wheel 121 is shown; Figure 6B for Figure 2 An enlarged view of a second specific product example of the outer wheel 102 and the inner wheel 121 is shown; Figure 6C for Figure 2 An enlarged view of a third specific product example of the outer wheel 102 and the inner wheel 121 is shown; Fig.6D for Figure 2 The fourth specific product example of the outer wheel 102 and the inner wheel 121 is shown in enlarged view. Among them, Figure (a) shows the matching state of the outer wheel 102 and the inner wheel 121, Figure (b) shows the outer wheel 102, Figure (c) shows the inner wheel 121, and Figure (d) shows an enlarged view of the meshing section 336 on the radial section of the outer wheel 102.

[0070] exist Fig. 6A Figures (a) to (c) show enlarged views drawn at a scale of 1:30. Figure 2 The first specific example of the outer wheel 102 and the inner wheel 121 is shown. 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 of 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 module of the teeth is 2.4 mm. The tooth top height of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is 2.4 mm. Figure (d) draws the specific curve of the meshing section 336 on the radial section of the outer wheel 102 at a scale of 1:1500.

[0071] exist Figure 6B Figures (a) to (c) show enlarged views drawn at a scale of 1:30. Figure 2The second specific example of the outer wheel 102 and the inner wheel 121 is shown. In the 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 of 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 module of the teeth is 1.4 mm. The tooth top height of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is 1.5 mm. Figure (d) draws the specific curve of the meshing section 336 on the radial section of the outer wheel 102 at a scale of 1:2400.

[0072] exist Figure 6C Figures (a) to (c) show enlarged views drawn at a scale of 1:30. Figure 2 The third specific example of the outer wheel 102 and the inner wheel 121 is shown. In the 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 of the outer wheel 102 and the inner wheel 121 is 2 (i.e., a difference of two teeth). The eccentricity e between the outer wheel 102 and the inner wheel 121 is 2.0 mm. The module of the teeth is 2.0 mm. The tooth top height of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is 2.0 mm. Figure (d) draws the specific curve of the meshing section 336 on the radial section of the outer wheel 102 at a scale of 1:3000.

[0073] exist Fig.6D Figures (a) to (c) are enlarged views drawn at a scale of 1:50 showing Figure 2 The fourth specific example of the outer wheel 102 and the inner wheel 121 is shown. In the 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 of the outer wheel 102 and the inner wheel 121 is 3 (i.e., a three-tooth difference). The eccentricity e between the outer wheel 102 and the inner wheel 121 is 2.3 mm. The module of the teeth is 1.0 mm. The tooth top height of the inner wheel outer teeth 400 and the outer wheel inner teeth 300 is 0.6 mm. Figure (d) draws the specific curve of the meshing section 336 on the radial section of the outer wheel 102 at a scale of 1:4000.

[0074] Although only some features of the present application have been illustrated and described herein, various modifications and changes may be made to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all the above modifications and changes that fall within the spirit and scope of the present application.

Claims

1. An internal meshing transmission mechanism (100), characterized in that: include: An outer wheel (102), wherein a first number of outer wheel internal teeth (300) are disposed on an inner edge of the outer wheel (102), each of the outer wheel internal teeth (300) comprising an outer wheel internal tooth top (302) and an outer wheel internal tooth waist symmetrical with respect to the outer wheel internal tooth top (302), and the outer wheel internal tooth waist comprising a meshing portion; and An inner wheel, wherein a second number of inner wheel external teeth (400) are arranged on an outer edge of the inner wheel, each of the inner wheel external teeth (400) comprises an inner wheel external tooth top (402) and an inner wheel external tooth waist symmetrical with respect to the inner wheel external tooth top (402), the inner wheel external tooth waist comprises a meshing portion, and the first number is greater than the second number; The inner wheel is arranged inside the outer wheel (102) and rotates eccentrically relative to the outer wheel (102), and the inner wheel and the outer wheel (102) form an internal meshing transmission through meshing of a meshing portion of an outer tooth waist of the inner wheel and a meshing portion of an inner tooth waist of the outer wheel; The meshing portion of the outer wheel inner teeth waist and the meshing portion of the inner wheel outer teeth waist are curved surfaces with the same shape and capable of overlapping, and the outer wheel inner teeth waist and the inner wheel outer teeth waist are designed as follows: when the outer wheel (102) is meshed with the inner wheel for transmission, at least one of the inner wheel outer teeth (400) can mesh with the outer wheel inner teeth (300), and for each of the inner wheel outer teeth (400) meshed with the outer wheel inner teeth (300), as the inner wheel rotates eccentrically, the meshing portion of at least one of the inner wheel outer teeth waist and the meshing portion of the outer wheel inner teeth waist can form a surface contact meshing, and the meshing portion of at least one of the inner wheel outer teeth waist and the meshing portion of the outer wheel inner teeth waist overlap in a fully meshed state.

2. The internal gear transmission mechanism (100) according to claim 1, characterized in that: As the inner wheel rotates eccentrically, the contact area formed when the inner wheel outer teeth waist contact the outer wheel inner teeth waist changes.

3. The internal gear transmission mechanism (100) according to claim 2, characterized in that: As the inner wheel rotates eccentrically, the contact area formed when the inner wheel outer tooth waist contacts the outer wheel inner tooth waist can gradually increase, then transition to gradually decrease, and gradually separate.

4. The internal gear transmission mechanism (100) according to claim 3, characterized in that: The outer wheel inner teeth waist and the inner wheel outer teeth waist are designed as follows: for each inner wheel outer teeth (400) meshing with the outer wheel inner teeth (300), the two inner wheel outer teeth waists of the inner wheel outer teeth (400) are meshed with the outer wheel inner teeth waist of the outer wheel inner teeth (300), and the meshing is a surface contact meshing.

5. The internal gear transmission mechanism (100) according to claim 4, characterized in that: The outer wheel inner teeth waist and the inner wheel outer teeth waist are designed such that: for each inner wheel outer tooth (400) meshing with the outer wheel inner teeth (300), the meshing portion of the inner wheel outer teeth waist and the meshing portion of the outer wheel inner teeth waist have a partial meshing state and a full meshing state; When the meshing portion of the inner wheel outer gear waist and the meshing portion of the outer wheel inner gear waist are in the partially meshing state, a portion of the meshing portion of the inner wheel outer gear waist can form a surface contact meshing with a portion of the meshing portion of the outer wheel inner gear waist; When the meshing portion of the inner wheel outer teeth waist and the meshing portion of the outer wheel inner teeth waist are in the fully meshed state, the meshing portion of the outer wheel inner teeth waist can have a maximum contact area with the meshing portion of the inner wheel outer teeth waist; Wherein, when the meshing portion of the inner wheel outer gear waist starts to mesh or disengage with the meshing portion of the outer wheel inner gear waist, the inner wheel outer gear waist and the outer wheel inner gear waist form the partial meshing state.

6. The internal gear transmission mechanism (100) according to claim 5, characterized in that: When the meshing portion of the inner wheel outer gear waist and the meshing portion of the outer wheel inner gear waist are meshed from the beginning to the complete meshing state, the contact area of ​​the meshing portion of the inner wheel outer gear waist and the meshing portion of the outer wheel inner gear waist is gradually increased; When the meshing portion of the inner wheel outer gear waist and the meshing portion of the outer wheel inner gear waist are disengaged from the fully engaged state, the contact area of ​​the meshing portion of the inner wheel outer gear waist and the meshing portion of the outer wheel inner gear waist gradually decreases.

7. The internal gear transmission mechanism (100) according to claim 6, characterized in that: The meshing parts of the inner wheel outer teeth waists on both sides of the inner wheel outer teeth tops (402) are symmetrically arranged about the inner wheel outer teeth center line (Y); The meshing portion of the outer wheel inner teeth waist of the outer wheel inner teeth (300) and the meshing portion of the outer wheel inner teeth waist of the adjacent outer wheel inner teeth (300) are symmetrically arranged about the outer wheel inner teeth center line (X); When the inner wheel is meshed with the outer wheel (102), and the center line (Y) of the inner wheel outer teeth coincides with the center line (X) of the outer wheel inner teeth, the inner wheel outer teeth (400) and the outer wheel inner teeth (300) are in the fully meshed state.

8. The internal gear transmission mechanism (100) according to claim 6, characterized in that: The outer wheel inner teeth (300) and the inner wheel outer teeth (400) are both spur gears; Wherein, on the radial cross-section of the inner wheel and the outer wheel (102), the tooth waist of the inner wheel inner teeth and the tooth waist of the inner wheel outer teeth are continuous smooth curves, and the curve direction of the meshing portion of the tooth waist of the inner wheel inner teeth is convex toward the outside of the teeth of the inner wheel inner teeth (300), and the curve direction of the meshing portion of the tooth waist of the inner wheel outer teeth is concave toward the inside of the teeth of the inner wheel outer teeth (400).

9. The internal gear transmission mechanism (100) according to claim 1, characterized in that: A difference between the first number and the second number is 1.

10. The internal gear transmission mechanism (100) according to claim 7, characterized in that: When the meshing portion of the inner wheel outer teeth waist and the meshing portion of the outer wheel inner teeth waist are in the fully meshing state, on the cross section of the outer wheel inner teeth (300) and the inner wheel outer teeth (400), the length of the contact line between the meshing portion of the inner wheel outer teeth waist and the meshing portion of the outer wheel inner teeth waist is greater than 1% of the length of the inner wheel outer teeth waist.

11. The internal gear transmission mechanism (100) according to claim 8, characterized in that: On the radial cross-section of the inner wheel and the outer wheel (102), the curve of the meshing portion of the inner wheel outer tooth waist and the meshing portion of the outer wheel inner tooth waist is not an involute.

Images