Joint, mechanical arm, robot and harmonic reducer device thereof

Abstract

The present invention relates to the field of robots, and provides a robot, a mechanical arm, a joint and a harmonic reducer device thereof, which includes a cup-shaped flexible wheel, a rigid wheel meshing with the flexible wheel and a wave generator, wherein the wave generator includes a sleeve for power input and a wave generator body arranged on the sleeve, an end cover, and a first stop structure and a second stop structure for stopping the sleeve, wherein the first stop structure adopts a non-bearing structure and is sleeved on the sleeve. A gap is formed between the sleeve and the end cover, and the first stop structure seals the gap, and the axial dimension of the first stop structure is smaller than the difference between the inner diameter and the outer diameter of the first stop structure. The present invention breaks through the conventional practice of abandoning the use of bearings and replacing them with a first stop structure whose axial dimension is smaller than the difference between the inner diameter and the outer diameter. When the radial dimension of the rigid wheel remains unchanged, the axial dimension of the harmonic reducer device is directly changed to meet the demand for a more miniaturized harmonic reducer device, thereby meeting the market demand.

Description

[0001] This application is a divisional application of the Chinese patent application entitled "Joints, robotic arms, robots and harmonic reducer devices thereof", patent application number 202111160367.6 and application date September 30, 2021. Technical Field

[0002] The present invention relates to the technical field of robots, and in particular to a joint, a mechanical arm, a robot and a harmonic reducer device thereof. Background Art

[0003] A robot usually includes a mechanical arm and a joint that enables the mechanical arm to rotate. A harmonic reducer is used at the joint to adjust the speed. The harmonic reducer is composed of three main components, namely a fixed rigid wheel, a flexible wheel, and a wave generator that causes the flexible wheel to deform radially. The inner wheel has an internal gear, and the flexible wheel is a thin-walled cylindrical external gear that is easily deformed. The power is transmitted through the meshing of the internal gear and the external gear. Without the action of the wave generator, the gaps between the teeth of the rigid wheel and the flexible wheel are uniform, and there is no power transmission at this time. Under the action of the wave generator, the generator installed in the flexible wheel causes the flexible wheel to deform radially and become an ellipse. At this time, on the long axis of the ellipse, the teeth are meshed along the entire working height, and on the short axis, a radial gap is formed between the tooth tops. During the rotation of the generator, the shape of the flexible wheel is always close to the ellipse, realizing the reduction transmission.

[0004] Harmonic reducers have the advantages of high load-bearing capacity, large transmission ratio, small size, smooth transmission and high transmission accuracy. They are widely used in electronics, aerospace, robotics and other industries.

[0005] The common harmonic reducer adopts a top-hat type flexible wheel, please refer to Figure 1 The flexible wheel 10 includes a cylindrical body 11 and an annular fixing platform 12 which is perpendicular to the axis of the cylindrical body 11 and folded outwards. The core of the cylindrical body 11 is provided with a central cavity (not shown) extending along the axis direction and completely passing through. The outer circumferential surface of the cylindrical body 11 is provided with an annular gear belt 13 extending along the axis direction and composed of single gear teeth distributed in an annular array. When the size of the cylindrical body 11 of the flexible wheel is determined, due to the existence of the annular fixing platform 12 folded outwards, the size of the harmonic reducer 100 cannot be further miniaturized in the space area occupied by the annular fixing platform 12.

[0006] During the years of scientific and technological research and development, researchers invented a cup-type flexible gear and applied it to harmonic reducers. Figure 2The flexible wheel 10a includes an annular rotating body 11a and an annular fixed platform 12a which is perpendicular to the axis of the annular rotating body 11a and folded inward. Since the top-hat type flexible wheel 10 is replaced by the cup-type flexible wheel 10a, the space area occupied by the outward-turned fixed platform 12 of the top-hat type flexible wheel 10 is reduced, so that the harmonic reducer 100a has a smaller size, and the joint size of the robot using such a harmonic reducer 100a is also smaller, and the entire robot appears to be particularly small.

[0007] However, as people become more and more enthusiastic about robots, there are higher requirements for miniaturization of robots, which is mainly reflected in the joints. Smaller harmonic reducers are a hot topic in the market, but over the past years, there has still not been a more miniaturized product on the market. Summary of the invention

[0008] The purpose of the embodiments of the present invention is to provide a harmonic reducer device to solve the technical problem that the size of the existing harmonic reducer device does not meet people's demand for a smaller size.

[0009] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a harmonic reducer device, which includes a cup-shaped flexible wheel, a rigid wheel meshing with the flexible wheel and a wave generator, the wave generator includes a sleeve for power input and a wave generator body arranged on the sleeve and causing the flexible wheel to undergo radial deformation under the rotation of the sleeve to change the meshing position of the flexible wheel and the rigid wheel, the harmonic reducer device also includes end covers and output bearings arranged oppositely, the harmonic reducer device also includes a first stop structure and a second stop structure for stopping the sleeve, the first stop structure adopts a non-bearing structure and is sleeved on the sleeve.

[0010] In one embodiment, a gap is formed between the sleeve and the end cover, and the first stop structure seals the gap.

[0011] In one embodiment, the axial dimension of the first stop structure is smaller than the difference between the inner diameter and the outer diameter of the first stop structure.

[0012] In one embodiment, the first stop structure and the second stop structure stop the sleeve in both axial directions.

[0013] In one embodiment, a first step is formed on the outer annular surface of the sleeve, a surrounding plate is formed on the outer side surface of the end cover, and the first stop structure is arranged between the first step and the surrounding plate.

[0014] In one embodiment, the first stop structure includes a stopper mounted on the sleeve and rotating with the rotation of the sleeve and a seal rotating relative to the stopper. The seal is fixedly connected to the end cover, the stopper abuts against the first step, and the seal abuts against the enclosure.

[0015] In one embodiment, a sealing structure is formed between the stopper and the seal, and the sealing structure includes an annular groove and a convex ring inserted into the annular groove. One of the stopper and the seal has an annular groove, and the other of the stopper and the seal has a convex ring.

[0016] In one embodiment, at least one of the stopper and the sealing member is in the form of a sheet.

[0017] In one embodiment, the first stop structure includes a stopper which is mounted on the sleeve and rotates with the rotation of the sleeve, and a seal connected to the stopper; the inner side surface of one end of the stopper abuts against the first step, and the outer side surface of one end of the seal abuts against the enclosure.

[0018] In one embodiment, the seal and the enclosure are always in contact when the seal rotates, and a sealing structure is formed at the contact between the seal and the enclosure.

[0019] In one embodiment, the stopper includes a fixed portion with a U-shaped cross-section, an extension portion extending from a side of the fixed portion close to the wave generator body away from the sleeve direction, and an inclined portion extending from a side edge of the extension portion away from the sleeve away from the sleeve and obliquely extending toward the enclosure, and the sealing member includes a stopper fixed in the fixed portion and a contact portion extending from a side of the stopper away from the sleeve and close to the enclosure toward the enclosure, and the contact portion is in contact with the enclosure.

[0020] In one embodiment, a panel is formed on the outer side of the end cover, and the first stop structure includes a connecting ring connected to a side of the panel close to the sleeve, and a sealing structure is formed between the connecting ring and the outer ring surface of the sleeve.

[0021] In one embodiment, the connecting ring forms surface contact with the outer annular surface of the sleeve, and the sealing structure is at least one annular groove provided on the contact surface between the connecting ring and the sleeve.

[0022] In one embodiment, the end cover includes a main body, a rigid wheel is fixed between the inner end surface of the main body and the outer ring of the output bearing, and a surrounding plate is connected to the outer end edge of the main body and is integrated with the main body.

[0023] In one embodiment, the second stop structure is a stop bearing, and a projection of the power output end of the wave generator and the stop bearing on the axis of the sleeve at least partially overlaps.

[0024] In one embodiment, the overlap ratio between the power output end of the wave generator and the projection of the stop bearing on the axis of the sleeve is in the range of 0.1-1.

[0025] In one embodiment, the overlap ratio of the projection of the power output end of the wave generator and the stop bearing on the axis of the sleeve is in the range of 0.5-0.9.

[0026] In one embodiment, the second stop structure is a stop bearing, the harmonic reducer device further comprises an output shaft fixedly connected to the inner ring of the output bearing, and the stop bearing is located between the output shaft and the sleeve.

[0027] In one embodiment, a mounting portion is convexly disposed on the outer ring surface of the output shaft, and the mounting portion and the cup bottom of the flexspline are fixed to the inner ring of the output bearing together.

[0028] In one embodiment, the inner annular surface of the sleeve is provided with a second step; one side of the stop bearing abuts against the second step, and the other side indirectly abuts against the bottom of the cup of the flexible wheel, and the outer ring of the stop bearing abuts against the second step.

[0029] In one embodiment, the harmonic reducer device further includes an output shaft fixedly connected to the inner ring of the output bearing and another end cover located outside the output bearing, wherein the other end cover is connected to the inner ring of the output bearing.

[0030] In one embodiment, the other end cover and the output shaft are two independent components, and a wire harness structure is provided between the other end cover and the output shaft.

[0031] In one embodiment, the output bearing is a bearing with its own oil seal.

[0032] In one embodiment, the wave generator body includes a rotating arm formed on a sleeve and rollers installed on opposite ends of the rotating arm; or, the wave generator body includes a cam formed on the sleeve and a flexible bearing connected to the cam; or, the wave generator body includes an elliptical disk formed on the sleeve and a flexible bearing connected to the elliptical disk.

[0033] The purpose of an embodiment of the present invention is to provide a joint, which includes the harmonic reducer device in the above embodiment and a drive motor for inputting power to the sleeve.

[0034] In one embodiment, the joint further includes another bearing sleeved on the sleeve and a mounting member for limiting the position of the other bearing, an accommodating space is formed between the stator and the rotor of the motor, and the other bearing is located in the accommodating space.

[0035] In one embodiment, the mounting member includes a plate body and a limiting ring connected to one side of the plate body, the limiting ring and the sleeve radially limit the other bearing, the outer ring surface of the sleeve is formed with a third step, and the third step and the plate body axially limit the other bearing.

[0036] An object of an embodiment of the present invention is to provide a robotic arm comprising the joints in the above embodiment.

[0037] An object of an embodiment of the present invention is to provide a robot, which includes the robotic arm in the above embodiment.

[0038] The beneficial effects provided by the present invention are:

[0039] The harmonic reducer device in this embodiment breaks the convention. The first stop structure does not use a bearing structure, but uses a first stop structure with an axial size smaller than that of a conventional bearing that provides an axial limit function to replace the conventional bearing, which has achieved an innovative breakthrough in reducing the axial size. Since the existing bearings need to add balls between the inner ring and the outer ring, in order to allow the balls to run safely and reliably between the inner ring and the outer ring, the axial size of the inner ring and the outer ring cannot be made very small. The present invention directly breaks the convention by abandoning the use of bearings and replacing them with a first stop structure with an axial size smaller than that of a conventional bearing. Under the condition that the radial size of the rigid wheel remains unchanged, the axial size of the harmonic reducer device is directly changed to meet the demand for a more miniaturized harmonic reducer device, thus meeting the market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 This is a cross-sectional diagram of a harmonic reducer using a top-hat type flexible wheel.

[0042] Figure 2 This is a cross-sectional diagram of a harmonic reducer using a cup-type flexible wheel.

[0043] Figure 3 A schematic diagram of the three-dimensional structure of a robot provided in an embodiment of the present invention.

[0044] Figure 4 for Figure 3 The schematic diagram of the plane structure of the robot shown.

[0045] Figure 5 for Figure 4 Schematic diagram of the assembly of one of the joints of the robot shown.

[0046] Figure 6 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the first embodiment is applied to the joint.

[0047] Figure 7 The harmonic reducer device provided by the first embodiment of the present invention is shown Figure 2 Comparison chart of the axial dimensions of harmonic reducers.

[0048] Figure 8 for Figure 5 A magnified view of a part of a joint.

[0049] Fig. 9 for Figure 8 Enlarged view of circle B.

[0050] Fig.10 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the second embodiment is applied to the joint.

[0051] Fig.11 for Fig.10 Magnified view of circle C in the joint.

[0052] Fig.12 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the third embodiment is applied to the joint.

[0053] Fig.13 for Fig.12 Magnified view of circle D in the joint.

[0054] Fig.14 The harmonic reducer device provided by the third embodiment of the present invention is shown Figure 2 Comparison chart of the axial dimensions of harmonic reducers.

[0055] Fig.15 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the fourth embodiment is applied to the joint.

[0056] Fig.16 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the fifth embodiment is applied to the joint.

[0057] Fig.17 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the sixth embodiment is applied to the joint.

[0058] Fig.18 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the seventh embodiment is applied to the joint.

[0059] Fig.19 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the eighth embodiment is applied to the joint.

[0060] Fig. 20 for Figure 5A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the ninth embodiment is applied to the joint.

[0061] Fig.21 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the tenth embodiment is applied to the joint.

[0062] Fig. 22 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the eleventh embodiment is applied to the joint.

[0063] Fig.23 for Figure 5 A schematic cross-sectional view of a joint along line AA, wherein the harmonic reducer device of the twelfth embodiment is applied to the joint.

[0064] The label details are as follows:

[0065] 10. Flexspline; 11. Cylinder; 12. Fixing table; 13. Toothed belt; 100. Harmonic reducer;

[0066] 10a, flexible wheel; 11a, rotating body; 12a, fixed platform; 100a, harmonic reducer; 20a, wave generator; 21a, sleeve; 22a, roller; 30a, first positioning bearing; 40a, second positioning bearing; 50a, first end cover; 60a, rigid wheel; 70a, roller bearing; 51a, connecting flange; 71a, outer ring of roller bearing 70a; 80a, output shaft; 52a, fixing plate; 81a, washer; 82a, radial connecting part; 83a, axial ring part; 93a, second end cover; 95a, an oil seal is arranged on the inner side of the second end cover 93a;

[0067] 200, robot; 203, base; 201, mechanical arm; 202, arm body; 204, joint; 9, motor; 100b, harmonic reducer device; 10b, flexible wheel; 60b, rigid wheel; 20b, wave generator; 21b, sleeve; 22b, wave generator body; 90b, end cover; 70b, output bearing; 30b, first stop structure; 40b, second stop structure; 40b, stop bearing; 91b, enclosure; 92b, body of end cover 90b; 61b, first fixing member; 80b, output shaft; 81b, gasket; 82b, mounting part; 93b, other end cover; 1b, harness structure; 95b, output bearing 70b is self-contained oil seal; 209, housing of brake 205; 208, limit ring; 207, plate body; 2 06, mounting member; 205, brake; 92, stator; 91, rotor; 101, another bearing; 11b, ring; 12b, cup bottom; 14b, accommodating space; 23b, first step; 24b, second step; 72b, inner ring of output bearing 70b; 31b, stopper; 32b, seal; 33b, sealing structure; 34b, annular groove; 35b, convex ring; 36b, groove wall; 37b, groove bottom; 38b, corner; 94b, connecting part; 101b, tube body; 102b, telescopic part; 103b, cable; 2b, outer periphery of mounting member 206; 94, housing of motor 9; 93, accommodating space; 95, elastic member; 27b, third step; 25b, elliptical disk; 26b, flexible bearing; 73b, accommodating groove;

[0068] 100c, harmonic reducer device; 21c, sleeve; 30c, first stop structure; 31c, stop member; 32c, seal member; 23c, first step; 91c, enclosure; 22c, wave generator body; 301c, fixing portion; 302c, extension portion; 303c, inclined portion; 320c, stop member; 321c, contact portion;

[0069] 100d, harmonic reducer device; 21d, sleeve; 30d, first stopper structure; 90d, end cover; 91d, enclosure; 92d, connecting ring; 33d, sealing structure; 34d, ring groove; 36d, groove wall surface; 37d, groove bottom surface; 38d, corner; 9d, motor; 921d, stator; 911d, rotor; 93d, accommodating space;

[0070] 100e, harmonic reducer device; 93e, the other end cover; 80e, output shaft; 70e, output bearing; 72e, inner ring of output bearing 70e; 10e, flexible wheel; 12e, cup bottom;

[0071] 100f, harmonic reducer device; 93f, the other end cover; 80f, output shaft; 70f, output bearing; 72f, inner ring of output bearing 70f; 10f, flexible wheel; 12f, cup bottom;

[0072] 100g, harmonic reducer device; 93g, the other end cover; 80g, output shaft; 70g, output bearing; 72g, inner ring of output bearing 70g; 10g, flexible wheel; 12g, cup bottom;

[0073] 100h, harmonic reducer device; 40h, second stop structure; 21h, sleeve; 20h, wave generator; 81h, washer; 82h, radial connection part; 83h, axial ring part; 10h, flexible wheel; 12h, cup bottom; 24h, second step;

[0074] 100i, harmonic reducer device; 100k, harmonic reducer device; 100m, harmonic reducer device; 100n, harmonic reducer device; 100p, harmonic reducer device; 40i, second stopper structure; 40k, second stopper structure; 93m, other end cover; 93n, other end cover; 93p, other end cover; 21i, sleeve; 21k, sleeve; 80m, output shaft; 80n, output shaft; 80p, output shaft; 20i, wave generator; 20k, wave generator; 70m, output bearing; 70 n, output bearing; 70p, output bearing; 81i, washer; 81k, washer; 72m, inner ring; 72n, inner ring; 72p, inner ring; 82i, radial connecting portion; 82k, radial connecting portion; 10m, flexible wheel; 10n, flexible wheel; 10p, flexible wheel; 83i, axial ring portion; 83k, axial ring portion; 12m, cup bottom; 12n, cup bottom; 12p, cup bottom; 10i, flexible wheel; 10k, flexible wheel; 12i, cup bottom; 12k, cup bottom; 24i, second step; 24k, second step. DETAILED DESCRIPTION

[0075] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0076] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0077] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0078] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] As people are more enthusiastic about robots, they have higher requirements for miniaturization of robots, which is mainly reflected in the joints. Smaller harmonic reducers are a hot topic in the market, but in the past few years, there has still been no more miniaturized product on the market. Please refer to Figure 2 The application of the cup-type flexible wheel 10a in the harmonic reducer achieves the purpose of reducing the size of the harmonic reducer. At the same time, when the cup-type flexible wheel 10a is used, the sleeve 21a of the wave generator 20a is respectively provided with a first locating bearing 30a and a second locating bearing 40a at the inner end and the outer end corresponding to the roller 22a, so as to realize the axial bidirectional positioning of the sleeve 21a. Figure 2 The structure of the cup-shaped flexible wheel 10a, sleeve 21a, first locating bearing 30a and second locating bearing 40a shown in the figure is the best choice at present. In the process of developing the harmonic reducer in a smaller size, the researchers have formed a fixed mindset and will not change it. Figure 2 The structural scheme of the cup-type flexible wheel 10a, the sleeve 21a, the first locating bearing 30a and the second locating bearing 40a shown in the figure is directed to other directions, for example:

[0080] 1. Improve the first end cover 50a. Can we make innovations in the size of the first end cover 50a?

[0081] 2. Improve the rigid wheel 60a. Can we make innovations in the size of the rigid wheel 60a?

[0082] 3. Can the flexible pulley 10a be improved and innovation be made in the size of the flexible pulley 10a?

[0083] 4. Improve the roller bearing 70a. Can we make innovations in the size of the roller bearing 70a?

[0084] However, after years of efforts by industry researchers, no good results have been achieved. Specifically, with respect to the first point, in addition to satisfying the fixed connection strength of the connecting flange 51a, the rigid wheel 60a and the outer ring 71a of the roller bearing 70a, the first end cover 50a must also leave space for the first positioning bearing 30a. It is difficult to make a breakthrough in this regard. With respect to the second and third points, the harmonic reducer 100a adjusts the speed by changing the meshing position of the rigid wheel 60a and the flexible wheel 10a. After a certain speed ratio is determined, the parameters of the meshing teeth of the flexible wheel 10a and the rigid wheel 60a are fixed. Due to the limitations of the existing gear processing level, it is difficult to achieve a smaller meshing ratio. The same speed ratio can be achieved by meshing the teeth, so it is difficult to reduce the volume by adjusting the radial dimensions of the flexible wheel 10a and the rigid wheel 60a. In addition, in order to achieve power transmission through the meshing of the flexible wheel 10a and the rigid wheel 60a, the structural strength of the flexible wheel 10a and the rigid wheel 60a must meet the standards, so it is also difficult to make a breakthrough in the axial dimensions of the flexible wheel 10a and the rigid wheel 60a. Regarding the fourth point, the roller bearing 70a is a direct part that transmits power to the output shaft 80a, and its structural strength also needs to meet the standards. There is no substantial breakthrough in the size of the roller bearing 70a.

[0085] Therefore, for many years, there has been no more compact product on the market. However, the applicant has spent a huge amount of R&D costs to research this technology, breaking the original structure of the cup-shaped flexible wheel 10a, sleeve 21a, first locating bearing 30a and second locating bearing 40a (such as Figure 2 As shown in FIG. 1 , a new structural solution is innovatively proposed to make the harmonic reducer 100a even smaller than the original relatively small solution. The smaller harmonic reducer 100a makes the joints using the harmonic reducer 100a even smaller, and at the same time, the robots using the joints also become even smaller.

[0086] The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments:

[0087] See also Figure 3and Figure 4 An embodiment of the present invention provides a robot 200, which includes a base 203 and a robotic arm 201 connected to the base 203. The robotic arm 201 includes at least two arm bodies 202 and joints 204 connected between the arm bodies 202. The movement of the robotic arm 201 is achieved through the joints 204.

[0088] Please also see Figure 5 and Figure 6 The joint 204 includes a motor 9 and a harmonic reducer device 100b connected to the motor 9. Figure 5 and Figure 6 A harmonic reducer device 100b provided by a first embodiment of the present invention is shown.

[0089] The harmonic reducer device 100b includes a cup-shaped flexible wheel 10b, a rigid wheel 60b meshing with the flexible wheel 10b, and a wave generator 20b. The wave generator 20b includes a sleeve 21b for power input and a wave generator body 22b disposed on the sleeve 21b and causing the flexible wheel 10b to undergo radial deformation under the rotation of the sleeve 21b to change the meshing position of the flexible wheel 10b and the rigid wheel 60b.

[0090] The harmonic reducer device 100b further includes an end cover 90b and an output bearing 70b which are arranged opposite to each other. The harmonic reducer device 100b further includes a first stop structure 30b and a second stop structure 40b which stop the sleeve 21b. The first stop structure 30b adopts a non-bearing structure and is sleeved on the sleeve 21b.

[0091] The axial dimension of the first stop structure 30b is smaller than the axial dimension of a conventional bearing providing an axial limiting function. For example, the axial dimension of the first stop structure 30b is smaller than Figure 2 The axial dimension of the first locating bearing 30a is shown.

[0092] The harmonic reducer device 100b in this embodiment breaks the convention. The first stop structure 30b does not use a bearing structure, but uses a first stop structure 30b with an axial size smaller than that of a conventional bearing that provides an axial limiting function to replace the conventional bearing, which has achieved an innovative breakthrough in reducing the axial size. Since existing bearings require balls to be added between the inner ring and the outer ring, in order to allow the balls to run safely and reliably between the inner ring and the outer ring, the axial size of the inner ring and the outer ring cannot be made very small. The present invention directly breaks the convention by abandoning the use of bearings and replacing them with a first stop structure 30b with an axial size smaller than that of conventional bearings. Under the condition that the radial size of the rigid wheel 60b remains unchanged, the axial size of the harmonic reducer device 100b is directly changed to meet the needs of a more miniaturized harmonic reducer device 100b, thus meeting the market demand. It should be noted that the conventional bearings mentioned here can be Figure 2The first locating bearing 30a is shown.

[0093] Please also see Figure 7 , Figure 7 The harmonic reducer device 100b provided by the embodiment of the present invention is shown. Figure 2 The axial dimension comparison diagram of the harmonic reducer 100a is shown in FIG. 1 . It can be seen from the figure that under the same radial dimension L of the rigid wheel 60b, the axial dimension is significantly reduced. Specifically, it can be seen from the figure that the line W is used as a reference and the element that has a limiting function on the left side of the first stop structure 30b is used as a starting point (for Figure 2 For example, the fixed plate 52a is taken as the starting point. Figure 7 For example, taking the left side of the enclosure 91b as the starting point and the cup bottom 12b of the flexible wheel 10b as the end point, the distance between the two is measured. A1 is obviously smaller than A2. The harmonic reducer device 100b provided by the embodiment of the present invention is smaller than Figure 2 The axial dimension of the harmonic reducer 100a is significantly reduced. In this embodiment, the axial dimension is reduced by 5 mm to 13 mm. Preferably, the axial dimension is reduced by 8 mm to 10 mm.

[0094] Please refer again Figure 5 and Figure 6 A gap (not shown) is formed between the sleeve 21b and the end cover 90b. The first stop structure 30b seals the gap.

[0095] In this embodiment, the first stopping structure 30b and the second stopping structure 40b stop the sleeve 21b in both axial directions.

[0096] The outer annular surface of the sleeve 21b is formed with a first step 23b. The outer side surface of the end cover 90b is formed with a shroud 91b. The first stop structure 30b is disposed between the first step 23b and the shroud 91b. The first stop structure 30b limits its bidirectional movement in the axial direction of the sleeve 21b through the first step 23b and the shroud 91b. In the present embodiment, the first step 23b is formed by reducing the diameter of the sleeve 21b at a position corresponding to the first stop structure 30b. In other embodiments, the first step 23b may be formed by increasing the diameter of the sleeve 21b on the right side of the position of the sleeve 21b corresponding to the first stop structure 30b, where the "right side" refers to the side of the first stop structure 30b close to the wave generator body 22b.

[0097] In this embodiment, the first stopper structure 30b includes a stopper 31b which is sleeved on the sleeve 21b and rotates with the rotation of the sleeve 21b, and a seal 32b which rotates relative to the stopper 31b, the seal 32b is fixedly connected to the end cover 90b, the stopper 31b abuts against the first step 23b, and the seal 32b abuts against the enclosure 91b. By replacing the bearing structure with two relatively rotating stoppers 31b and seals 32b, a smaller axial dimension can be achieved without hindering the rotation of the sleeve 21b relative to the end cover 90b.

[0098] The revolving pair between the stopper 31b and the seal 32b is formed in the overlapped portion between the outer side of the stopper 31b and the inner side of the seal 32b. It should be noted that the outer side of the stopper 31b refers to the side away from the wave generator body 22b, and the inner side of the seal 32b refers to the side close to the wave generator body 22b.

[0099] The projections of the sealing member 32b and the stopper 31b in a direction parallel to the axis of the sleeve 21b at least partially overlap, and a rotation pair of the first stopper structure 30b is formed in the overlapping portion.

[0100] The positions of the stopper 31b and the sleeve 21b are relatively fixed, so that the stopper 31b rotates with the rotation of the sleeve 21b. The sealing member 32b is fixedly connected to the end cover 90b, so that the stopper 31b can be used as a rotor and the sealing member 32b can be used as a stator.

[0101] In this embodiment, the first stop structure 30b is composed of a stopper 31b and a seal 32b. The first stop structure 30b is composed of only two parts, which is one less part than a conventional bearing in terms of the number of parts. Specifically, a conventional bearing includes an inner ring, an outer ring, and a ball disposed between the inner ring and the outer ring, and has three parts, while the first stop structure 30b in the present invention has only two parts, namely, the stopper 31b and the seal 32b. From the perspective of reducing material costs due to the reduction in parts alone, the present invention has a great breakthrough.

[0102] In this embodiment, the axial dimension of the first stop structure 30b is smaller than the difference between the inner diameter and the outer diameter of the first stop structure 30b. The harmonic reducer device 100b in this embodiment breaks the convention. The first stop structure 30b does not adopt a bearing structure, but adopts a first stop structure 30b whose axial dimension is smaller than the difference between the inner diameter and the outer diameter to replace the conventional bearing, and has made an innovative breakthrough in reducing the axial dimension. Due to the existing bearings, balls need to be added between the inner ring and the outer ring. In order to allow the balls to run safely and reliably between the inner ring and the outer ring, the axial dimensions of the inner ring and the outer ring cannot be made very small. Usually, the axial dimension of the inner ring or the outer ring is equal to the difference between the inner diameter and the outer diameter of the bearing, or the axial dimension of the inner ring or the outer ring is greater than the difference between the inner diameter and the outer diameter of the bearing. The difference between the inner diameter and the outer diameter of the bearing mentioned here refers to the diameter difference or radius difference between the inner ring and the outer ring. The present invention directly breaks through the conventional practice of abandoning the use of bearings and replaces them with a structure in which the axial dimension is smaller than the difference between the inner diameter and the outer diameter. Under the condition that the radial dimension of the rigid wheel 60b remains unchanged, the axial dimension of the harmonic reducer device 100b is directly changed to meet the demand for a more miniaturized harmonic reducer device 100b, thus catering to the market demand.

[0103] In this embodiment, a sealing structure 33b is formed between the stopper 31b and the sealing member 32b to achieve a sealing effect and prevent the lubricating oil in the inner cavity of the harmonic reducer device 100b from leaking.

[0104] In this embodiment, the sealing structure 33b includes an annular groove 34b and a convex ring 35b inserted into the annular groove 34b. One of the stopper 31b and the sealing member 32b is provided with an annular groove 34b, and the other of the stopper 31b and the sealing member 32b is provided with a convex ring 35b. The cooperation between the annular groove 34b and the convex ring 35b not only does not hinder the relative rotation between the stopper 31b and the sealing member 32b, but also provides a sealing function for the rotating pair between the stopper 31b and the sealing member 32b. The specific sealing effect is achieved by the labyrinth-like matching surface of the annular groove 34b and the convex ring 35b.

[0105] Please also see Figure 8 and Fig. 9 In this embodiment, the annular groove 34b and the convex ring 35b have at least three mating surfaces, including two groove wall surfaces 36b and a groove bottom surface 37b connecting the two groove wall surfaces 36b. A corner 38b is formed between the groove bottom surface 37b and each groove wall surface 36b. With this arrangement, even if the lubricating oil wants to flow out, it must pass through two groove wall surfaces 36b, one groove bottom surface 37b and two corners 38b. Such a long path will eventually prevent the lubricating oil from flowing out, thereby achieving the purpose of sealing and preventing leakage.

[0106] The axial dimension between the stopper 31b and the sealing member 32b is further reduced by the cooperation of the annular groove 34b and the convex ring 35b. At the same time, the stopper 31b has a certain supporting effect on the sealing member 32b through the cooperation of the annular groove 34b and the convex ring 35b. Of course, the stopper 31b also has a certain supporting effect on the end cover 90b through the sealing member 32b.

[0107] The annular groove 34b and the convex ring 35b are arranged in pairs, which can be arranged as one pair, two pairs, three pairs or more. The specific number of pairs needs to be based on the radial dimension difference between the end cover 90b and the sleeve 21b and the thickness of the convex ring 35b. The radial dimension difference between the end cover 90b and the sleeve 21b mentioned here refers to the radial distance between the end cover 90b and the sleeve 21b, specifically the radial distance between the main body 92b of the end cover 90b and the sleeve 21b. In this embodiment, the annular groove 34b and the convex ring 35b are arranged in two pairs.

[0108] At least one of the stopper 31b and the seal 32b is in a sheet shape. The sheet shape here means that the axial dimension is smaller than the difference between the inner diameter and the outer diameter. In this embodiment, the stopper 31b and the seal 32b are both in a sheet shape, the axial dimension of the stopper 31b is smaller than the difference between the inner diameter and the outer diameter of the stopper 31b, and the axial dimension of the seal 32b is smaller than the difference between the inner diameter and the outer diameter of the seal 32b. In other embodiments, one of the stopper 31b and the seal 32b can be selected to be in a sheet structure.

[0109] The end cover 90b includes a main body 92b, and a rigid wheel 60b is fixed between the inner end surface of the main body 92b and the outer ring of the output bearing 70b. The inner end surface of the main body 92b here refers to the end surface of the main body 92b close to the output bearing 70b. An annular cavity is formed between the inner end surface of the main body 92b and the outer ring of the output bearing 70b, and the rigid wheel 60b is arranged in the annular cavity and clamped between the inner end surface of the main body 92b and the outer ring of the output bearing 70b. The main body 92b, the rigid wheel 60b and the outer ring of the output bearing 70b are fixed together by a first fixing member 61b.

[0110] In this embodiment, the enclosure 91b is connected to the outer edge of the main body 92b and is integrated with the main body 92b. In other words, the enclosure 91b does not exist as a separate component, but is integrated with the main body 92b of the end cover 90b. This arrangement can reduce the number of components, reduce the additional processing costs of the enclosure 91b as a separate component, and also reduce the processing and assembly processes of the enclosure 91b as a separate component, saving the cost of the harmonic reducer device 100b to a certain extent. Please refer to Figure 2 The component that acts as the enclosure 91b is the fixing plate 52a on the outside of the first end cover 50a, and this fixing plate 52a, Figure 2 As separate parts, the number of parts has been increased invisibly, and the inventory space has been increased, the types of parts inventory control have been increased, the processing and assembly steps have been increased, and of course, the cost has also been increased.

[0111] In this embodiment, the flexible wheel 10b is cup-shaped, and includes a ring portion 11b and a cup bottom 12b connected to the ring portion 11b. The cup bottom 12b is formed by extending one end edge of the ring portion 11b inward. The cup bottom 12b is provided with a through hole (not marked) for the output shaft 80b to pass through. The outer ring surface of the ring portion 11b is provided with an external gear (not marked) for meshing with the internal gear (not marked) of the rigid wheel 60b. The ring portion 11b and the cup bottom 12b form a receiving space 14b, and the wave generator body 22b and the second stop structure 40b are located in the receiving space 14b.

[0112] The rigid wheel 60b is annular, and an internal gear is formed inside the rigid wheel 60b and meshes with the flexible wheel 10b. The flexible wheel 10b is disposed in the inner cavity of the rigid wheel 60b.

[0113] In this embodiment, the second stop structure 40b is a stop bearing 40b, and the power output end of the wave generator 20b overlaps at least partially with the projection of the stop bearing 40b on the axis of the sleeve 21b. In this way, the overall axial size of the stop bearing 40b and the power output end of the generator is reduced. Please refer to Figure 2 , Figure 2 The power output end of the wave generator 20a in the harmonic reducer 100a shown does not overlap with the projection of the second locating bearing 40a on the axis of the sleeve 21a. In the present invention, the power output end of the wave generator 20b overlaps with the projection of the stop bearing 40b on the axis of the sleeve 21b, and the size in the axis direction of the sleeve 21b is smaller. The industry's consistent design scheme for harmonic reducers is like Figure 2 As shown, the two stop bearings 30a and 40a are arranged on opposite sides of the power output end of the wave generator 20a without overlapping. However, the present invention breaks the convention and creatively improves the structural position relationship between the stop bearing 40b and the power output end of the wave generator 20b, so that the power output end of the wave generator 20b and the projection of the stop bearing 40b on the axis of the sleeve 21b at least partially overlap, further reducing the axial size of the harmonic reducer device 100b, and making further contribution to the miniaturization development of the harmonic reducer device 100b.

[0114] In this embodiment, the projection overlap ratio of the power output end of the wave generator 20b and the stop bearing 40b on the axis of the sleeve 21b is in the range of 0.1-1. Specifically, the projection overlap ratio can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9. The projection overlap ratio mentioned here refers to the cross section parallel to the axial direction of the sleeve 21b, and is defined as follows: A is the axial length of the projection overlap of the stop bearing 40b and the power output end of the wave generator 20b on the axis of the sleeve 21b; B is the axial length of the stop bearing 40b or the axial length of the power output end of the wave generator 20b; C is the projection overlap ratio; wherein, C=A / B, that is, the projection overlap ratio C is equal to the ratio of A to B.

[0115] Preferably, the overlap ratio of the projections of the power output end of the wave generator and the stop bearing on the axis of the sleeve is in the range of 0.5-0.9.

[0116] Guided by the idea of ​​making the power output end of the wave generator 20b overlap with the projection of the stop bearing 40b on the axis of the sleeve 21b, the R&D personnel continued to study and experiment, and made samples of finished products and tested them. They unexpectedly found in a large number of samples that "the overlap rate between the power output end of the wave generator and the projection of the stop bearing on the axis of the sleeve is in the range of 0.5-0.9", which not only can make a greater contribution to the axial size, but also can ensure the product reliability.

[0117] The inner ring surface of the sleeve 21b is provided with a second step 24b; one side of the stop bearing 40b abuts against the second step 24b, and the other side indirectly abuts against the cup bottom 12b of the flexible wheel 10b. The second step 24b is formed by increasing the inner diameter of the sleeve 21b at the position corresponding to the second stop structure 40b.

[0118] The harmonic reducer device 100b also includes an output shaft 80b fixedly connected to the inner ring 72b of the output bearing 70b, and the stop bearing 40b is located between the output shaft 80b and the sleeve 21b. When designing the harmonic reducer device 100b, the industry usually thinks that the stop bearing 40b is set on the periphery of the sleeve 21b, and does not think of placing the stop bearing 40b between the sleeve 21b and the output shaft 80b. The present invention proposes a new design idea, which directly sets the stop bearing 40b between the sleeve 21b and the output shaft 80b, and at the same time extends the stop bearing 40b below the power output end of the wave generator 20b, and the sleeve 21b is between the stop bearing 40b and the power output end of the wave generator 20b. The sleeve 21b and the output shaft 80b radially limit the stop bearing 40b, and no additional limiting structure is required.

[0119] The harmonic reducer device 100b further includes a washer 81b disposed between the cup bottom 12b of the flexspline 10b and the stop bearing 40b. The washer 81b is in the form of a sheet. The washer 81b and the second step 24b limit the stop bearing 40b in both axial directions, and the sleeve 21b and the output shaft 80b limit the stop bearing 40b in radial directions, thereby limiting the stop bearing 40b in both axial and radial directions.

[0120] The washer 81b is in the form of a sheet. The washer 81b and the stop bearing 40b do not overlap in the axial direction of the sleeve 21b. The washer 81b and the stop bearing 40b are sleeved side by side on the sleeve 21b. Please refer to Figure 2 , Figure 2 The washer 81a in the embodiment includes a radial connecting portion 82a and an axial ring portion 83a, and the radial connecting portion 82a is used to radially limit the stop bearing 40b. In the present invention, the washer 81b only needs to be in a simple sheet shape and does not require a radial connecting portion 82a, so the structure is simpler and the assembly is also easier.

[0121] The outer ring surface of the output shaft 80b is convexly provided with a mounting portion 82b, and the mounting portion 82b is fixed to the inner ring 72b of the output bearing 70b together with the cup bottom 12b of the flexible wheel 10b. In the axial direction of the sleeve 21b, the stopper bearing 40b, the washer 81b, the cup bottom 12b of the flexible wheel 10b, the mounting portion 82b and the inner ring 72b of the output bearing 70b are closely arranged in sequence, and no other parts are arranged in between. The inner ring 72b of the output bearing 70b is provided with a receiving groove 73b on the inner side, and the mounting portion 82b is installed in the receiving groove 73b.

[0122] The harmonic reducer device 100b further includes another end cover 93b located outside the output bearing 70b, and the other end cover 93b is connected to the inner ring 72b of the output bearing 70b. The outer side of the output bearing 70b mentioned here refers to the side of the output bearing 70b away from the rigid wheel 60b.

[0123] The other end cover 93b and the output shaft 80b are two independent parts. A wire harness structure 1b is arranged between one side of the other end cover 93b and the output shaft 80b. The other end cover 93b and the output shaft 80b are arranged as two independent parts, which can reduce the Figure 2 The inconvenience of processing and installation caused by the integral structure of the output shaft 80a and the second end cover 93a shown in the figure also reduces the cost. On the other hand, a wiring harness structure 1b can be provided between the other end cover 93b and the end of the output shaft 80b, thus achieving two goals at one stroke.

[0124] The other end cover 93b is provided with a connecting portion 94b on one side close to the output bearing 70b, and the connecting portion 94b extends into the inner ring 72b of the output bearing 70b and close to the end of the output shaft 80b. In this embodiment, the cable harness structure 1b includes a tube body 101b connected to the connecting portion 94b and an elastic telescopic portion 102b sleeved on the outside of the tube body 101b. The tube body 101b is for the cable 103b to pass through. One end of the tube body 101b extends into the output shaft 80b, and the other end is connected to the connecting portion 94b. The telescopic portion 102b is located between the tube body 101b and the connecting portion 94b.

[0125] In this embodiment, the wave generator body 22b includes an elliptical disk 25b formed on the sleeve 21b and a flexible bearing 26b connected to the elliptical disk 25b. In other embodiments, the wave generator body 22b includes a rotating arm formed on the sleeve 21b and rollers installed at opposite ends of the rotating arm; or, the wave generator body 22b includes a cam formed on the sleeve 21b and a flexible bearing 26b connected to the cam.

[0126] In this embodiment, the output bearing 70b is a bearing with its own oil seal 95b, and does not need to be Figure 2 The harmonic reducer shown needs to be provided with an oil seal 95a on the inner side of the second end cover 93a. The oil seal 95a provided on the inner side of the second end cover 93a needs to be customized, which is more costly.

[0127] In summary, the harmonic reducer device 100b of the present invention is more cost-effective than Figure 2 The harmonic reducer 100a shown in the figure reduces the power consumption by nearly 20%. The specific performance is as follows:

[0128] 1. Figure 2 The rigid wheel 60a and the flexible wheel 10a of the harmonic reducer 100a shown in the figure need to be customized, while the harmonic reducer device 100b of the present invention only needs to use the standard parts of the rigid wheel 60b and the flexible wheel 10b to meet the design requirements, thereby reducing the customization cost;

[0129] 2. Figure 2 The roller bearing 70a of the harmonic reducer 100a shown in the figure is a bearing without an oil seal, and the oil seal is customized and designed between the right end cover 93a and the roller bearing 70a, while the present invention uses an output bearing 70b with its own oil seal 95b, which does not need to be designed separately, thereby reducing the customization cost;

[0130] 3. Figure 2 In the harmonic reducer 100a shown in the figure, the component that plays the role of the enclosure 91b is the fixing plate 52a on the outside of the first end cover 50a, and this fixing plate 52a is Figure 2The existence of the enclosing plate 91b as a separate component in the end cap 90b virtually increases the number of components, requires additional inventory space, increases the types of inventory control of components, increases processing steps and assembly steps, and of course, increases costs. In the present invention, the enclosing plate 91b is connected to the outer edge of the main body 92b and is integrated with the main body 92b. The enclosing plate 91b does not exist as a separate component, but is integrated with the main body 92b of the end cap 90b. This arrangement can reduce the number of components, reduce the additional processing costs of the enclosing plate 91b as a separate component, and also reduce the processing steps and assembly steps of the enclosing plate 91b as a separate component, saving the cost of the harmonic reducer device 100b to a certain extent;

[0131] 4. Figure 2 In the harmonic reducer 100a shown, the output shaft 80a and the right end cover 93a are integrated, and the volume of the entire part is very large. The right end cover 93a and the output shaft 80a are almost perpendicular, which invisibly increases the processing difficulty and the processing cost. In the present invention, the output shaft 80b is separated from the other end cover 93b. During processing, the output shaft 80b and the other end cover 93b are processed separately. Although the number of processed parts is increased, in fact, the cost is reduced compared with the increase in processing cost caused by the processing difficulty.

[0132] The joint 204 also includes a drive motor 9 for inputting power to the sleeve 21b. The drive motor 9 is arranged on one side of the harmonic reducer device 100b. The joint 204 also includes another bearing 101 sleeved on the sleeve 21b, and the drive motor 9 includes a rotor 91 sleeved on the sleeve 21b and a stator 92 matched with the rotor 91. The other bearing 101 is located on the side of the rotor away from the wave generator 20b. The other bearing 101 is located on the side of the rotor 91 away from the other end cover 93b.

[0133] The joint 204 further comprises a mounting member 206 sleeved on the sleeve 21 b . The mounting member 206 is located on a side of the motor 9 away from the end cover 90 b and is used to limit the position of the other bearing 101 .

[0134] An accommodating space 93 is formed between the stator 92 and the rotor 91 of the motor 9, and the other bearing 101 is located in the accommodating space 93 and does not occupy the axial space of the joint 204. The mounting member 206 includes a plate body 207 and a limiting ring 208 connected to one side of the plate body 207. The limiting ring 208 and the sleeve 21b radially limit the other bearing 101. The outer ring surface of the sleeve 21b is formed with a third step 27b. The third step 27b and the plate body 207 axially limit the other bearing 101. The limiting ring 208 extends into the accommodating space 93. An elastic member 95 is provided between the other bearing 101 and the plate body 207 to play a shock absorbing role.

[0135] The joint 204 further includes a brake 205 mounted on the sleeve 21b. The brake 205 is located outside the mounting member 206. The mounting member 206 is located between the brake 205 and the motor 9. The outer peripheral portion 2b of the mounting member 206 is sandwiched between the housing 94 of the motor 9 and the housing 209 of the brake 205 to achieve the fixing of the mounting member 206.

[0136] The mounting member 206 utilizes the original gap between the existing motor and the brake to realize the installation of another bearing 101. By extending the limit ring 208 into the accommodating space 93 of the motor 9, the outer peripheral portion 2b of the mounting member 206 is connected in an offset manner between the outer casing 94 of the motor 9 and the housing 209 of the brake 205, and does not increase the axial dimension of the entire joint.

[0137] In summary, the harmonic reducer device 100b is reduced in axial dimension, and the radial dimension of the rigid wheel 60b remains unchanged, so as to meet the requirement of miniaturization of the harmonic reducer device 100b. At the same time, the joint 204 using the harmonic reducer device 100b will also be miniaturized. Furthermore, the mechanical arm 201 using such miniaturized joint will also be miniaturized. The robot 200 using such a mechanical arm is also miniaturized.

[0138] Please also see Fig.10 and Fig.11 The harmonic reducer device 100c provided in the second embodiment of the present invention is substantially the same as the harmonic reducer device 100b provided in the first embodiment, except that:

[0139] The first stop structure 30c includes a stopper 31c which is sleeved on the sleeve 21c and rotates with the rotation of the sleeve 21c, and a seal 32c connected to the stopper 31c; the inner side surface of one end of the stopper 31c abuts against the first step 23c, and the outer side surface of one end of the seal 32c abuts against the enclosure 91c, thereby realizing the first stop structure 30c being limited between the first step 23c and the enclosure 91c. The inner side surface here refers to the side close to the wave generator body 22c, and the outer side surface refers to the side away from the wave generator body 22c. The one end of the stopper 31c here refers to the end close to the sleeve 21c, and the one end of the seal 32c refers to the end close to the enclosure 91c and away from the sleeve 21c.

[0140] The first stop structure 30c is in the shape of a sheet as a whole. The overall axial dimension of the first stop structure 30c is smaller than the difference between the inner diameter and the outer diameter of the first stop structure 30c. The seal 32c rotates with the stopper 31c along with the sleeve 21c. A revolving pair is formed between the seal 32c and the enclosure 91c. When the sleeve 21c rotates, the outer edge of one end of the seal 32c contacts the enclosure 91c to form a revolving pair. The outer edge of one end of the seal 32c is always in contact with the enclosure 91c when the seal 32c rotates, and a sealing structure is formed at the contact point between the seal 32c and the enclosure 91c.

[0141] The stopper 31c is annular and includes a fixing portion 301c with a U-shaped cross section, an extension portion 302c extending from a side of the fixing portion 301c close to the wave generator body 22c away from the sleeve 21c, and an inclined portion 303c extending from a side edge of the extension portion 302c away from the sleeve 21c and away from the sleeve 21c and toward the enclosure 91c.

[0142] The sealing member 32c is annular and includes a stopper 320c fixed in the fixing portion 301c and a contact portion 321c extending obliquely from the side of the stopper 320c away from the sleeve 21c and close to the enclosure 91c toward the enclosure 91c. The included angle between the contact portion 321c and the stopper 320c is an obtuse angle.

[0143] The stopper 31c is a rigid member, and the sealing member 32c is a flexible member. When the first stopper structure 30c rotates with the sleeve 21c, the contact portion 321c and the enclosure plate 91c are always pressed and closely contacted, which not only achieves the function of limiting, but also plays a role of sealing.

[0144] Please also see Fig.12 and Fig.13 The harmonic reducer device 100d provided in the third embodiment of the present invention is substantially the same as the harmonic reducer device 100b provided in the first embodiment, except that:

[0145] The first stop structure 30d sleeved on the sleeve 21d is directly formed on the end cover 90d, and the axial stop function is no longer achieved through a separate component, thereby reducing the number of components.

[0146] In the third embodiment, the first stop structure 30d is directly formed on the enclosure 91d. The first step is no longer needed for limiting. The first stop structure 30d includes a connecting ring 92d connected to the side of the enclosure 91d close to the sleeve 21d, and the connecting ring 92d forms a surface contact with the outer ring surface of the sleeve 21d.

[0147] A sealing structure 33d is formed between the connecting ring 92d and the outer ring surface of the sleeve 21d. The sealing structure 33d is a ring groove 34d formed on the contact surface between the connecting ring 92d and the sleeve 21d. The ring groove 34d includes two groove walls 36d and a groove bottom surface 37d connecting the two groove walls 36d. A corner 38d is formed between the groove bottom surface 37d and each groove wall surface 36d. In this arrangement, even if the lubricating oil wants to flow out, it must pass through two groove walls 36d, one groove bottom surface 37d and two corners 38d. Such a long path will eventually prevent the lubricating oil from flowing out, thereby achieving the purpose of sealing and preventing leakage.

[0148] A plurality of annular grooves 34d may be provided, for example, 1, 2, 3, etc. When the axial dimension is reduced, the number of annular grooves 34d may be set according to the situation.

[0149] In this embodiment, the Figure 2 The first locating bearing 30a of the harmonic reducer 100a shown in the figure is used, and the axial dimension of the first stop structure 30d is smaller than Figure 2 The sum of the axial dimensions of the fixing plate 52a and the first locating bearing 30a of the harmonic reducer 100a shown.

[0150] In this embodiment, the connecting ring 92d can extend toward the motor 9d. It can be understood that in order to further reduce the axial dimension, the connecting ring 92d can extend into the accommodating space 93d between the stator 921d and the rotor 911d of the motor 9d.

[0151] Please also see Fig.14 , Fig.14 The harmonic reducer device 100d provided by the third embodiment of the present invention is shown. Figure 2 The axial dimensions of the harmonic reducer 100a are compared in FIG. 1 . It can be seen from the figure that, under the same radial dimensions L of the rigid wheels 60d and 60a, the axial dimensions are significantly reduced. Specifically, the line W in the figure is used as a reference, and the element that functions as a limit on the left side of the first stop structure 30d is used as a starting point (for Figure 2 For example, the fixed plate 52a is used as the starting point. Fig.14 For example, taking the left side of the first stop structure 30d as the starting point and the cup bottom 12d of the flexible wheel as the end point, measuring the distance between the two, A1 is obviously smaller than A2, and the harmonic reducer device 100d provided by the embodiment of the present invention is smaller than Figure 2 The axial dimension of the harmonic reducer 100a is significantly reduced. In this embodiment, the axial dimension is reduced by 5 mm to 13 mm. Preferably, the axial dimension is reduced by 8 mm to 10 mm.

[0152] In the first, second and third examples above, three different solutions of the first stop structure are provided. In other embodiments, the first stop structure may be other supporting structures such as a bushing.

[0153] It should be noted that in this embodiment, the concept of the stopper means blocking, and it does not necessarily have to be in contact all the time. It can serve as a stopper when it needs to be blocked in the direction of movement. In other embodiments, the stopper can have the function of sealing and / or positioning, and positioning means that the position does not move.

[0154] See also Fig.15 The harmonic reducer device 100e provided in the fourth embodiment of the present invention is substantially the same as the harmonic reducer device 100b provided in the first embodiment, except that:

[0155] The other end cover 93e is integral with the output shaft 80e. The mounting portion 82b is no longer provided on the output shaft 80e, and the inner ring 72e of the output bearing 70e does not need to be provided with the receiving groove 73b. The cup bottom 12e of the flexible wheel 10e is directly fixed to the inner ring 72e of the output bearing 70e. The mounting portion 82b is no longer provided between the cup bottom 12e of the flexible wheel 10e and the inner ring 72e of the output bearing 70e. The cup bottom 12e of the flexible wheel 10e is directly in contact with the inner ring 72e of the output bearing 70e. The fixing of the output shaft 80e and the inner ring 72e of the output bearing 70e is achieved by fixing the other end cover 93e to the inner ring 72e of the output bearing 70e.

[0156] See also Fig.16 The harmonic reducer device 100f provided in the fifth embodiment of the present invention is substantially the same as the harmonic reducer device 100c provided in the second embodiment, and the difference is the same as the difference between the harmonic reducer device 100e provided in the fourth embodiment of the present invention and the harmonic reducer device 100b provided in the first embodiment, that is, the other end cover 93f is integrated with the output shaft 80f. No mounting portion is provided on the output shaft 80f, and the inner ring 72f of the output bearing 70f does not need to be provided with a receiving groove. The cup bottom 12f of the flexible wheel 10f is directly fixed to the inner ring 72f of the output bearing 70f. No mounting portion is provided between the cup bottom 12f of the flexible wheel 10f and the inner ring 72f of the output bearing 70f. The cup bottom 12f of the flexible wheel 10f is directly in contact with the inner ring 72f of the output bearing 70f. The fixing of the output shaft 80f and the inner ring 72f of the output bearing 70f is achieved by fixing the other end cover 93f and the inner ring 72f of the output bearing 70f.

[0157] See also Fig.17The harmonic reducer device 100g provided in the sixth embodiment of the present invention is substantially the same as the harmonic reducer device 100d provided in the third embodiment, and the difference is the same as the difference between the harmonic reducer device 100e provided in the fourth embodiment of the present invention and the harmonic reducer device 100b provided in the first embodiment, that is, the other end cover 93g is integrated with the output shaft 80g. No mounting portion is provided on the output shaft 80g, and the inner ring 72g of the output bearing 70g does not need to be provided with a receiving groove. The cup bottom 12g of the flexible wheel 10g is directly fixed to the inner ring 72g of the output bearing 70g. No mounting portion is provided between the cup bottom 12g of the flexible wheel 10g and the inner ring 72g of the output bearing 70g. The cup bottom 12g of the flexible wheel 10g is directly in contact with the inner ring 72g of the output bearing 70g. The fixing of the output shaft 80g and the inner ring 72g of the output bearing 70g is achieved by fixing the other end cover 93g and the inner ring 72g of the output bearing 70g.

[0158] See also Fig.18 The harmonic reducer device 100h provided in the seventh embodiment of the present invention is substantially the same as the harmonic reducer device 100b provided in the first embodiment, except that:

[0159] The second stop structure 40h is sleeved on the periphery of the sleeve 21h. The second stop structure 40h does not overlap with the projection of the power output end of the wave generator 20h on the axis of the sleeve 21h. The washer 81h includes a radial connection portion 82h and an axial ring portion 83h extending inward from the radial connection portion 82h. The axial ring portion 83h is clamped between the second stop structure 40h and the cup bottom 12h of the flexible wheel 10h. The second step 24h is formed on the outer annular surface of the sleeve 21h. The second stop structure 40h is located between the second step 24h and the axial ring portion 83h at the axial upper limit. The second stop structure 40h is located between the radial connection portion 82h and the outer annular surface of the sleeve 21h at the radial upper limit.

[0160] See also Fig.19 The harmonic reducer device 100i provided in the eighth embodiment of the present invention is substantially the same as the harmonic reducer device 100c provided in the second embodiment, except that:

[0161] The second stop structure 40i is sleeved on the periphery of the sleeve 21i. The second stop structure 40i does not overlap with the projection of the power output end of the wave generator 20i on the axis of the sleeve 21i. The washer 81i includes a radial connection portion 82i and an axial ring portion 83i extending inward from the radial connection portion 82i. The axial ring portion 83i is clamped between the second stop structure 40i and the cup bottom 12i of the flexible wheel 10i. The second step 24i is formed on the outer annular surface of the sleeve 21i. The second stop structure 40i is located between the second step 24i and the axial ring portion 83i at the axial upper limit. The second stop structure 40i is located between the radial connection portion 82i and the outer annular surface of the sleeve 21i at the radial upper limit.

[0162] See also Fig. 20 The harmonic reducer device 100k provided in the ninth embodiment of the present invention is substantially the same as the harmonic reducer device 100d provided in the third embodiment, except that:

[0163] The second stop structure 40k is sleeved on the periphery of the sleeve 21k. The second stop structure 40k does not overlap with the projection of the power output end of the wave generator 20k on the axis of the sleeve 21k. The washer 81k includes a radial connection portion 82k and an axial ring portion 83k extending inward from the radial connection portion 82k. The axial ring portion 83k is clamped between the second stop structure 40k and the cup bottom 12k of the flexible wheel 10k. The second step 24k is formed on the outer annular surface of the sleeve 21k. The second stop structure 40k is located between the second step 24k and the axial ring portion 83k at the axial upper limit. The second stop structure 40k is located between the radial connection portion 82k and the outer annular surface of the sleeve 21k at the radial upper limit.

[0164] See also Fig.21 The harmonic reducer device 100m provided in the tenth embodiment of the present invention is substantially the same as the harmonic reducer device 100h provided in the seventh embodiment, except that:

[0165] The other end cover 93m is integral with the output shaft 80m. No mounting portion is provided on the output shaft 80m, and the inner ring 72m of the output bearing 70m does not need to be provided with a receiving groove. The cup bottom 12m of the flexible wheel 10m is directly fixed to the inner ring 72m of the output bearing 70m. No mounting portion is provided between the cup bottom 12m of the flexible wheel 10m and the inner ring 72m of the output bearing 70m. The cup bottom 12m of the flexible wheel 10m is directly in contact with the inner ring 72m of the output bearing 70m. The fixing of the output shaft 80m and the inner ring 72m of the output bearing 70m is achieved by fixing the other end cover 93m and the inner ring 72m of the output bearing 70m.

[0166] See also Fig. 22The harmonic reducer device 100n provided in the eleventh embodiment of the present invention is substantially the same as the harmonic reducer device 100i provided in the eighth embodiment, except that:

[0167] The other end cover 93n is integral with the output shaft 80n. No mounting portion is provided on the output shaft 80n, and the inner ring 72n of the output bearing 70n does not need to be provided with a receiving groove. The cup bottom 12n of the flexible wheel 10n is directly fixed to the inner ring 72n of the output bearing 70n. No mounting portion is provided between the cup bottom 12n of the flexible wheel 10n and the inner ring 72n of the output bearing 70n. The cup bottom 12n of the flexible wheel 10n is directly in contact with the inner ring 72n of the output bearing 70n. The fixing of the output shaft 80n and the inner ring 72n of the output bearing 70n is achieved by fixing the other end cover 93n and the inner ring 72n of the output bearing 70n.

[0168] See also Fig.23 The harmonic reducer device 100p provided in the twelfth embodiment of the present invention is substantially the same as the harmonic reducer device 100k provided in the ninth embodiment, except that:

[0169] The other end cover 93p is integral with the output shaft 80p. No mounting portion is provided on the output shaft 80p, and the inner ring 72p of the output bearing 70p does not need to be provided with a receiving groove. The cup bottom 12p of the flexible wheel 10p is directly fixed to the inner ring 72p of the output bearing 70p. No mounting portion is provided between the cup bottom 12p of the flexible wheel 10p and the inner ring 72p of the output bearing 70p. The cup bottom 12p of the flexible wheel 10p is in direct contact with the inner ring 72p of the output bearing 70p. The fixing of the output shaft 80p and the inner ring 72p of the output bearing 70p is achieved by fixing the other end cover 93p to the inner ring 72p of the output bearing 70p.

[0170] The twelve embodiments described above are all axially dimensioned relative to Figure 2 The harmonic reducer 100a shown is reduced in size and breaks the convention. The first stopper structure does not use a bearing structure, but uses a first stopper structure with an axial size smaller than that of a conventional bearing providing an axial limit function to replace the conventional bearing. When the radial size of the rigid wheel remains unchanged, the axial size of the harmonic reducer device is directly changed to meet the needs of a more miniaturized harmonic reducer device, thus meeting the market demand. At the same time, the cost is reduced to a greater or lesser extent.

[0171] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A harmonic reducer device, characterized in that: The harmonic reducer device includes a cup-shaped flexible wheel, a rigid wheel meshing with the flexible wheel, and a wave generator, wherein the wave generator includes a sleeve for power input and a wave generator body arranged on the sleeve, and the harmonic reducer device also includes an end cover connected to the rigid wheel, a gap is formed between the sleeve and the end cover, and the harmonic reducer device also includes a first stop structure and a second stop structure for stopping the sleeve, the first stop structure adopts a non-bearing structure and is sleeved on the sleeve, the first stop structure seals the gap, and the axial dimension of the first stop structure is smaller than the difference between the inner diameter and the outer diameter of the first stop structure.

2. The harmonic reducer device according to claim 1, characterized in that: The first stop structure includes a stopper which is sleeved on the sleeve and rotates with the rotation of the sleeve, and a sealing member which rotates relative to the stopper, and the sealing member is fixedly connected to the end cover.

3. The harmonic reducer device according to claim 2, characterized in that: The outer side surface of the end cover forms a surrounding plate, the outer annular surface of the sleeve forms a first step, the first stop structure is arranged between the first step and the surrounding plate, the stop member abuts against the first step, and the sealing member abuts against the surrounding plate.

4. The harmonic reducer device according to claim 2, characterized in that: A sealing structure is formed between the stopper and the sealing member, and the sealing structure includes an annular groove and a convex ring inserted into the annular groove. The annular groove is provided in one of the stopper and the sealing member, and the convex ring is convexly provided on the other of the stopper and the sealing member.

5. The harmonic reducer device according to claim 2, characterized in that: At least one of the stopper and the sealing member is in sheet shape.

6. The harmonic reducer device according to claim 1, characterized in that: The first stop structure includes a stopper which is sleeved on the sleeve and rotates with the rotation of the sleeve, and a sealing member connected to the stopper; a surrounding plate is formed on the outer side surface of the end cover, and the outer side surface of one end of the sealing member abuts against the surrounding plate.

7. The harmonic reducer device according to claim 6, characterized in that: A first step is formed on the outer annular surface of the sleeve, and an inner side surface of one end of the stopper abuts against the first step.

8. The harmonic reducer device according to claim 6, characterized in that: The seal is always in contact with the enclosure when the seal rotates, and a sealing structure is formed at the contact between the seal and the enclosure.

9. The harmonic reducer device according to claim 6, characterized in that: The stopper includes a fixed portion with a U-shaped cross-section, an extension portion extending from a side of the fixed portion close to the wave generator body away from the sleeve, and an inclined portion extending from a side edge of the extension portion away from the sleeve away from the sleeve and obliquely extending toward the enclosure. The sealing member includes a stopper fixed in the fixed portion and a contact portion extending obliquely toward the enclosure from a side of the stopper away from the sleeve and close to the enclosure, and the contact portion is in contact with the enclosure.

10. The harmonic reducer device according to claim 1, characterized in that: A surrounding plate is formed on the outer side surface of the end cover, and the first stop structure includes a connecting ring connected to a side of the surrounding plate close to the sleeve, and a sealing structure is formed between the connecting ring and the outer ring surface of the sleeve.

11. The harmonic reducer device according to claim 10, characterized in that: The connecting ring is in surface contact with the outer ring surface of the sleeve, and the sealing structure is at least one annular groove provided on the contact surface between the connecting ring and the sleeve.

12. The harmonic reducer device according to claim 1, characterized in that: The first stop structure and the second stop structure stop the sleeve in both axial directions.

13. The harmonic reducer device according to claim 1, characterized in that: The harmonic reducer device also includes an output bearing, which is arranged opposite to the end cover, and a surrounding plate is formed on the outer side of the end cover. The end cover includes a main body, and the rigid wheel is fixed between the inner end surface of the main body and the outer ring of the output bearing. The surrounding plate is connected to the outer end edge of the main body and is integrated with the main body.

14. The harmonic reducer device according to any one of claims 1 to 13, characterized in that: The second stop structure is a stop bearing, and the power output end of the wave generator at least partially overlaps with the projection of the stop bearing on the axis of the sleeve.

15. The harmonic reducer device according to claim 14, characterized in that: The overlap ratio of the projections of the power output end of the wave generator and the stop bearing on the axis of the sleeve is in the range of 0.1-1.

16. The harmonic reducer device according to claim 15, characterized in that: The overlap ratio of the projections of the power output end of the wave generator and the stop bearing on the axis of the sleeve is in the range of 0.5-0.

9.

17. The harmonic reducer device according to any one of claims 1 to 12, characterized in that: The second stop structure is a stop bearing, the harmonic reducer device also includes an output bearing, the output bearing is arranged opposite to the end cover, the harmonic reducer device also includes an output shaft fixedly connected to the inner ring of the output bearing, and the stop bearing is located between the output shaft and the sleeve.

18. The harmonic reducer device according to claim 17, characterized in that: The outer ring surface of the output shaft is convexly provided with a mounting portion, and the mounting portion and the cup bottom of the flexible wheel are fixed to the inner ring of the output bearing together.

19. The harmonic reducer device according to claim 17, characterized in that: The inner annular surface of the sleeve is provided with a second step; one side of the stop bearing abuts against the second step, and the other side indirectly abuts against the cup bottom of the flexible wheel, and the outer ring of the stop bearing abuts against the second step.

20. The harmonic reducer device according to any one of claims 1 to 12, characterized in that: The harmonic reducer device also includes an output bearing, which is arranged opposite to the end cover. The harmonic reducer device also includes an output shaft fixedly connected to the inner ring of the output bearing and another end cover located outside the output bearing, and the other end cover is connected to the inner ring of the output bearing.

21. The harmonic reducer device according to claim 20, characterized in that: The other end cover and the output shaft are two independent components, and a wire harness structure is arranged between the other end cover and the output shaft.

22. The harmonic reducer device according to claim 21, characterized in that: The other end cover is provided with a connecting portion protruding on a side close to the output bearing, the connecting portion extends into the inner ring of the output bearing and close to the end of the output shaft, the wiring harness structure includes a tube body connected to the connecting portion and an elastic telescopic portion sleeved on the outside of the tube body; one end of the tube body extends into the output shaft, and the other end is connected to the connecting portion; the telescopic portion is located between the tube body and the connecting portion.

23. The harmonic reducer device according to any one of claims 1 to 13, characterized in that: The wave generator body includes a rotating arm formed on the sleeve and rollers installed on opposite ends of the rotating arm; or, the wave generator body includes a cam formed on the sleeve and a flexible bearing connected to the cam; or, the wave generator body includes an elliptical disk formed on the sleeve and a flexible bearing connected to the elliptical disk.

24. The harmonic reducer device according to any one of claims 1 to 13, characterized in that: The harmonic reducer device also includes a washer arranged between the cup bottom of the flexible wheel and the second stop structure, the washer includes a radial connecting portion and an axial ring portion extending inward from the radial connecting portion, the axial ring portion is clamped between the second stop structure and the cup bottom of the flexible wheel, and the second stop structure is located between the radial connecting portion and the outer annular surface of the sleeve at a radial upper limit.

25. A joint, characterized in that: The joint includes a harmonic reducer device as described in any one of claims 1 to 24 and a drive motor for inputting power to the sleeve.

26. The joint according to claim 25, characterized in that: The joint further comprises another bearing sleeved on the sleeve and a mounting member for limiting the position of the other bearing. An accommodating space is formed between the stator and the rotor of the motor, and the other bearing is located in the accommodating space.

27. The joint according to claim 26, characterized in that: The mounting member includes a plate body and a limiting ring connected to one side of the plate body, the limiting ring and the sleeve radially limit the other bearing, the outer ring surface of the sleeve is formed with a third step, and the third step and the plate body axially limit the other bearing.

28. A robotic arm, characterized in that: The robotic arm comprises a joint as described in any one of claims 25-27.

29. A robot, characterized in that: The robot comprises the robotic arm of claim 28.

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