CN115289197B

CN115289197B - Joint, mechanical arm, robot and harmonic reducer device thereof

Info

Publication number: CN115289197B
Application number: CN202210887684.6A
Authority: CN
Inventors: 王重彬; 胡万权; 叶伟智; 刘主福; 刘培超
Original assignee: Shenzhen Yuejiang Technology Co Ltd
Current assignee: Shenzhen Yuejiang Technology Co Ltd
Priority date: 2021-09-30
Filing date: 2022-07-26
Publication date: 2024-05-31
Anticipated expiration: 2042-07-26
Also published as: WO2023051714A1; CN115199725B; CN113847404A; CN115199725A; CN115199724A; CN115289197A

Abstract

The invention relates to the field of robots, and provides a robot, a mechanical arm, a joint and a harmonic reducer device thereof, which comprises a cup-shaped flexible wheel, a rigid wheel meshed with the flexible wheel and a wave generator, wherein the wave generator comprises a sleeve for power input, a wave generator main body which is arranged on the sleeve and enables the flexible wheel to radially deform under the rotation of the sleeve so as to change the meshing position of the flexible wheel and the rigid wheel, an end cover and an output bearing which are oppositely arranged, and a first stop structure and a second stop structure for stopping the sleeve, wherein the projection of the power output end of the wave generator and the projection of the second stop structure on the axis of the sleeve are at least partially overlapped. The invention breaks through the conventional projection of the power output end of the wave generator and the second stop structure on the axis of the sleeve at least partially overlapped, and under the condition that the radial dimension of the rigid wheel is unchanged, the axial dimension of the harmonic speed reducer device is directly changed, so that the demand of more miniaturization of the harmonic speed reducer device is met, and the market demand is met.

Description

Joint, mechanical arm, robot and harmonic reducer device thereof

The present application claims priority from chinese patent application filed at the chinese patent office at 2021, 09 and 30, with application number 202111164470.8, entitled "joint, robotic arm, robot and harmonic reducer device thereof", the entire contents of which are incorporated herein by reference.

Technical Field

The invention relates to the technical field of robots, in particular to a joint, a mechanical arm, a robot and a harmonic reducer device thereof.

Background

Robots typically include a robotic arm, a joint that turns the arm, where a harmonic reducer is used to regulate the speed. The harmonic reducer consists of three main components, namely a fixed rigid gear, a flexible gear and a wave generator for radially deforming the flexible gear. The inner wheel is provided with an inner gear, the flexible wheel is a thin-walled cylindrical outer gear which is easy to deform, power is transmitted through the meshing of the inner gear and the outer gear, the gaps between the teeth of the rigid wheel and the teeth of the flexible wheel are uniform under the action of a no-wave generator, no deceleration power is transmitted at the moment, the flexible wheel is radially deformed into an oval shape by the generator arranged in the flexible wheel under the action of the wave generator, at the moment, on the major axis of the oval shape, the teeth are meshed along the whole working height, and on the minor axis, the radial gaps are formed between the tooth tops, and the shape of the flexible wheel is always close to the oval shape in the rotating process of the generator, so that deceleration transmission is realized.

The harmonic reducer has the advantages of high bearing capacity, large transmission ratio, small volume, stable transmission and high transmission precision, and is widely applied to industries such as electronics, aerospace, robots and the like.

As shown in fig. 1, the common harmonic reducer adopts a top hat type flexspline, the flexspline 10 includes a cylindrical body 11 and an annular fixing table 12 perpendicular to the axis of the cylindrical body 11 and turned outwards, a central cavity (not shown) extending along the axis direction and penetrating completely is formed in the core of the cylindrical body 11, and an annular gear tooth belt 13 extending along the axis direction and distributed in an annular array by a single gear tooth is arranged on the outer circumferential surface of the cylindrical body 11. In the case of sizing the flexible gear cylinder 11, the presence of the outwardly folded annular stationary table 12 tends to prevent the size of the harmonic reducer 100 from further miniaturizing in the space occupied by the annular stationary table 12.

In the technological development process for many years, scientific researchers have invented a cup-shaped flexible gear and applied it to a harmonic reducer, please refer to fig. 2, the flexible gear 10a includes an annular revolving body 11a and an annular fixed table 12a perpendicular to the axis of the annular revolving body 11a and turned inwards, because the top-hat-shaped flexible gear 10 is replaced by the cup-shaped flexible gear 10a, the space area occupied by the turned-out fixed table 12 of the top-hat-shaped flexible gear 10 is reduced, the harmonic reducer 100a has smaller size, and the robot joint size applying such a harmonic reducer 100a is smaller, so that the whole robot appears to be extremely small.

However, with the enthusiasm of people for robots, the requirements for miniaturization of robots are higher, the miniaturization is mainly reflected in joint positions, and smaller harmonic reducers are hot spots in the market, but no more miniaturized products are yet appeared in the market in the past years.

Disclosure of Invention

The embodiment of the invention aims to provide a harmonic reducer device, which aims to solve the technical problem that the size of the traditional harmonic reducer device does not meet the demand of people for miniaturization.

In order to achieve the above purpose, the invention adopts the following technical scheme: the utility model provides a harmonic reducer device, includes cupular flexspline, with flexspline engaged with rigid gear and ripples generator, ripples generator include power input's sleeve and set up in on the sleeve and make flexspline radial deformation is in order to change flexspline with the ripples generator main part of rigid gear engaged position, harmonic reducer device still includes relative end cover and the output bearing that sets up, harmonic reducer device still includes to the sleeve carries out first backstop structure and second backstop structure of backstop, ripples generator's power output with the projection of second backstop structure on the telescopic axis at least partially overlaps.

In one embodiment, the projected overlap ratio of the power output end of the wave generator and the second stop structure on the axis of the sleeve ranges from 0.1 to 1.

In one embodiment, the projected overlap of the power output end of the wave generator and the second stop structure on the axis of the sleeve ranges from 0.5 to 0.9.

In one embodiment, the second stop structure is a stop bearing.

In one embodiment, the harmonic reducer device further comprises an output shaft fixedly connected with the inner race of the output bearing, and the second stop structure is located between the output shaft and the sleeve.

In one embodiment, the first stop structure is a non-bearing structure and is sleeved on the sleeve.

In one embodiment, a gap is formed between the sleeve and the end cap, and the first stop structure seals the gap.

In one embodiment, the axial dimension of the first stop structure is less than the difference between the inner and outer diameters of the first stop structure.

In one embodiment, the first stop structure and the second stop structure axially bi-directionally stop the sleeve.

In one embodiment, the outer annular surface of the sleeve forms a first step, the outer side surface of the end cap forms a shroud, and the first stop structure is disposed between the first step and the shroud.

In one embodiment, the first stop structure comprises a stop piece sleeved on the sleeve and rotating along with the rotation of the sleeve and a sealing piece rotating relative to the stop piece, the sealing piece is fixedly connected with the end cover, the stop piece abuts against the first step, and the sealing piece abuts against the coaming.

In one embodiment, a sealing structure is formed between the stop piece and the sealing piece, the sealing structure comprises a ring groove and a convex ring inserted into the ring groove, one of the stop piece and the sealing piece is provided with the ring groove, and the other one of the stop piece and the sealing piece is provided with the convex ring in a convex manner.

In one embodiment, at least one of the stopper and the seal is sheet-shaped.

In one embodiment, the first stopping structure comprises a stopping piece sleeved on the sleeve and rotating along with the rotation of the sleeve and a sealing piece connected with the stopping piece; one end inner side surface of the stop piece is propped against the first step, and one end outer side surface of the sealing piece is propped against the coaming.

In one embodiment, the seal is in constant contact with the shroud as the seal rotates, forming a seal at the contact between the seal and the shroud.

In one embodiment, the stopper includes a fixing portion having a U-shaped cross section, an extending portion extending from a side of the fixing portion, which is close to the wave generator main body, away from the sleeve direction, and an inclined portion extending from a side edge of the extending portion, which is away from the sleeve, away from the sleeve direction and toward the shroud obliquely, and the sealing member includes a stopper portion fixed in the fixing portion and a contact portion extending from a side of the stopper portion, which is away from the sleeve and is close to the shroud, toward the shroud obliquely, and the contact portion contacts the shroud.

In one embodiment, the outer side of the end cap is formed with a shroud, the first stop structure comprises a connecting ring connected to one side of the shroud adjacent to the sleeve, and a sealing structure is formed between the connecting ring and the outer annular surface of the sleeve.

In one embodiment, the connecting ring is in surface contact with the outer annular surface of the sleeve, and the sealing structure is at least one annular groove formed on the contact surface between the connecting ring and the sleeve.

In one embodiment, the end cap comprises a body, the rigid wheel being secured between an inner end face of the body and an outer race of the output bearing, the shroud being connected to an outer end edge of the body and being integral with the body.

In one embodiment, the outer ring surface of the output shaft is convexly provided with a mounting part, and the mounting part and the cup bottom of the flexible gear are fixed on the inner ring of the output bearing together.

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

In one embodiment, the harmonic reducer device further comprises an output shaft fixedly connected with the inner ring of the output bearing and another end cover positioned outside the output bearing, wherein the other end cover is connected with the inner ring of the output bearing.

In one embodiment, 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.

In one embodiment, the output bearing is a self-contained oil-sealed bearing.

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

An object of an embodiment of the present invention is to further provide a joint, which includes the harmonic reducer device in the above embodiment and a driving motor for inputting power to the sleeve.

In one embodiment, the joint further comprises another bearing sleeved on the sleeve and a mounting piece used for limiting the other bearing, a containing space is formed between the stator and the rotor of the motor, and the other bearing is located in the containing space.

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, a third step is formed on an outer ring surface of the sleeve, and the third step and the plate body axially limit the other bearing.

The embodiment of the invention aims to provide a mechanical arm which comprises the joint in the embodiment.

The embodiment of the invention aims to provide a robot which comprises the mechanical arm in the embodiment.

The beneficial effects provided by the invention are as follows:

the harmonic reducer device in the embodiment breaks through the convention, creatively improves the structural position relation between the second stop structure and the power output end of the wave generator, enables the power output end of the wave generator and the projection of the second stop structure on the axis of the sleeve to be at least partially overlapped, reduces the axial size of the harmonic reducer device, and contributes to the miniaturization development of the harmonic reducer device. Under the condition that the radial dimension of the rigid wheel is unchanged, the axial dimension of the harmonic speed reducer device is directly changed, so that the demand of more miniaturization of the harmonic speed reducer device is met, and the market demand is met.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic cross-sectional view of a harmonic reducer using a top hat flex gear.

Fig. 2 is a schematic cross-sectional view of a harmonic reducer using a cup-type flexspline.

Fig. 3 is a schematic perspective view of a robot according to an embodiment of the present invention.

Fig. 4 is a schematic plan view of the robot shown in fig. 3.

Fig. 5 is an assembled schematic view of one of the joints of the robot shown in fig. 4.

Fig. 6 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein the harmonic reducer device of the first embodiment is applied to the joint.

Fig. 7 shows a comparison of the harmonic reducer device provided by the first embodiment of the present invention with the harmonic reducer of fig. 2 in axial dimension.

Fig. 8 is an enlarged view of a portion of the joint of fig. 5.

Fig. 9 is an enlarged view at circle B of fig. 8.

Fig. 10 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a harmonic reducer device of a second embodiment is applied to the joint.

Fig. 11 is an enlarged view of the joint of fig. 10 at circle C.

Fig. 12 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a third embodiment of a harmonic reducer assembly is applied to the joint.

Fig. 13 is an enlarged view of the joint of fig. 12 at circle D.

Fig. 14 shows a comparison of the harmonic reducer device provided by the third embodiment of the present invention with the harmonic reducer of fig. 2 in axial dimension.

Fig. 15 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a fourth embodiment of a harmonic reducer device is applied to the joint.

Fig. 16 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a fifth embodiment harmonic reducer device is applied to the joint.

Fig. 17 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a sixth embodiment of the harmonic reducer device is applied to the joint.

Fig. 18 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a seventh embodiment of the harmonic reducer arrangement is applied to the joint.

Fig. 19 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein the eighth embodiment of the harmonic reducer assembly is applied to the joint.

Fig. 20 is a schematic cross-sectional view of the joint of fig. 5 taken along line A-A, wherein a harmonic reducer device of the ninth embodiment is applied to the joint.

The reference numerals are as follows:

10. a flexible wheel; 11. a cylinder; 12. a fixed table; 13. a toothed belt; 100. a harmonic reducer;

10a, a flexible wheel; 11a, a revolving body; 12a, a fixed table; 100a, a harmonic reducer; 20a, a wave generator; 21a, a sleeve; 22a, rollers; 30a, a first positioning bearing; 40a, a second positioning bearing; 50a, a first end cap; 60a, rigid wheels; 70a, roller bearings; 51a, a connection flange; 71a, an outer ring of the roller bearing 70 a; 80a, an output shaft; 52a, a fixing plate; 81a, washers; 82a, radial connections; 83a, an axial ring portion; 93a, a second end cap; 95a, the inner side of the second end cover 93a is provided with an oil seal;

200. A robot; 203. a base; 201. a mechanical arm; 202. an arm body; 204. a joint; 9. a motor; 100b, a harmonic reducer device; 10b, a flexible wheel; 60b, rigid wheels; 20b, a wave generator; 21b, a sleeve; 22b, a wave generator body; 90b, end caps; 70b, an output bearing; 30b, a first stop structure; 40b, a second stop structure; 40b, stop bearings; 91b, coaming; 92b, a body of end cap 90 b; 61b, a first fixing member; 80b, an output shaft; 81b, washers; 82b, a mounting portion; 93b, another end cap; 1b, a wire harness structure; 95b, the output bearing 70b is self-contained oil seal; 209. a housing of the brake 205; 208. a limiting ring; 207. a plate body; 206. a mounting member; 205. a brake; 92. a stator; 91. a rotor; 101. another bearing; 11b, a ring portion; 12b, bottom of cup; 14b, an accommodation space; 23b, a first step; 24b, a second step; 72b, an inner race of the output bearing 70 b; 31b, a stopper; 32b, a seal; 33b, a sealing structure; 34b, ring grooves; 35b, a convex ring; 36b, groove wall surfaces; 37b, groove bottom surface; 38b, corner; 94b, a connection; 101b, a tube body; 102b, a telescopic part; 103b, a cable; 2b, an outer peripheral portion of the mount 206; 94. a housing of the motor 9; 93. an accommodating space; 95. an elastic member; 27b, a third step; 25b, an oval plate; 26b, flexible bearings; 73b, a receiving groove;

100c, a harmonic reducer device; 21c, a sleeve; 30c, a first stop structure; 31c, a stopper; 32c, a seal; 23c, a first step; 91c, coaming; 22c, a wave generator body; 301c, a fixing part; 302c, an extension; 303c, an inclined portion; 320c, a stop; 321c, contact portions;

100d, a harmonic reducer device; 21d, a sleeve; 30d, a first stop structure; 90d, end covers; 91d, coaming; 92d, a connecting ring; 33d, a sealing structure; 34d, ring grooves; 36d, groove wall surfaces; 37d, groove bottom surface; 38d, corner; 9d, a motor; 92d, a stator; 91d, a rotor; 93d, an accommodating space;

100e, harmonic reducer device; 93e, another end cap; 80e, an output shaft; 70e, an output bearing; 72e, an inner race of the output bearing 70 e; 10e, a flexible wheel; 12e, bottom of cup;

100f, a harmonic reducer device; 93f, another end cap; 80f, an output shaft; 70f, an output bearing; 72f, an inner race of the output bearing 70 f; 10f, a flexible wheel; 12f, the bottom of the cup;

100g, harmonic reducer device; 93g, another end cap; 80g, output shaft; 70g, output bearings; 72g, an inner race of the output bearing 70 g; 10g, a flexible wheel; 12g, bottom of cup;

100h, a harmonic reducer device; 30h, a first stop structure; 91h, coaming; 23h, a first step; 95h, an elastic piece; 9h, a motor; 92h, a stator; 94h, a rotor; 93h, an accommodating space;

100i, a harmonic reducer device; 93i, another end cap; 80i, an output shaft; 70i, output bearings; 72i, an inner race of the output bearing 70 i; 10i, a flexible wheel; 12i, bottom of cup;

100k, harmonic reducer means; 30k, a first stop structure; 91b, coaming; 90k, end caps; 910k, a protruding ring portion; 9k, a motor; 92k, stator; 91k, rotor; 98k, an accommodating space; 920k, check ring; 23k, first step; 21k, sleeve; 80k, output shaft; 40k, a second stop structure; 40k, seals; 34k, ring grooves; 24k, a second step; 10k, a flexible wheel; 12k, bottom of cup; 101k, another bearing; 22k, wave generator body.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In the description of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In addition, in the present invention, in each technical aspect in the claims, if "second" appears first in the aspect, it does not mean that "first" must appear in the technical aspect. The terms "first" and "second" are used for descriptive purposes only, and elements called the same name are distinguished by "first" and "second", e.g., first step, second step, where "first" and "second" merely distinguish the structures of steps.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

With the enthusiasm of people for robots, the requirements for miniaturization of robots are higher, the miniaturization is mainly reflected in joint parts, smaller harmonic reducers are hot spots in the market, but a product with more miniaturization still does not appear in the market for many years. Referring to fig. 2 again, the application of the cup-shaped flexspline 10a in the harmonic reducer achieves the purpose of reducing the size of the harmonic reducer, meanwhile, while the application of the cup-shaped flexspline 10a, the sleeve 21a of the wave generator 20a is respectively provided with the first positioning bearing 30a and the second positioning bearing 40a corresponding to the inner end and the outer end of the roller 22a, so as to realize the positioning of the sleeve 21a in the axial directions, the structural scheme of the cup-shaped flexspline 10a, the sleeve 21a, the first positioning bearing 30a and the second positioning bearing 40a shown in fig. 2 is a preferred scheme, and in the research and development process towards the miniaturization of the harmonic reducer, a researcher already generates a fixed thinking, and does not change the structural scheme of the cup-shaped flexspline 10a, the sleeve 21a, the first positioning bearing 30a and the second positioning bearing 40a shown in fig. 2, but strives towards other directions, for example:

1. improvements to the first end cap 50a can not be innovative in terms of the size of the first end cap 50 a;

2. the improvement of the rigid wheel 60a can not create innovations in terms of the size of the rigid wheel 60 a;

3. The improvement of the flexible gear 10a can not create innovation in the size of the flexible gear 10 a;

4. improvements to the roller bearing 70a can not be innovative in terms of the size of the roller bearing 70a, and so forth.

However, there has been no good result in many years of effort by the industry developer. Specifically, for point 1, the first end cap 50a, in addition to satisfying the fixed connection strength of the connection flange 51a, the rigid wheel 60a, and the outer ring 71a of the roller bearing 70a, also has to leave a receiving space for the first positioning bearing 30a, which is difficult to break through in this respect; for the 2 nd and 3 rd points, the harmonic reducer 100a realizes the adjustment of the rotation speed through the change of the meshing position of the rigid gear 60a and the flexible gear 10a, after a certain rotation speed ratio is determined, the parameters of the meshing teeth of the flexible gear 10a and the rigid gear 60a are fixed, the parameters are limited by the existing gear processing level, and the same rotation speed ratio is difficult to realize through smaller meshing teeth, so the purpose of reducing the volume is difficult to realize through adjusting the radial dimensions of the flexible gear 10a and the rigid gear 60a, in addition, the power transmission is realized through the meshing of the flexible gear 10a and the rigid gear 60a, and the structural strength of the flexible gear 10a and the rigid gear 60a needs to reach the standard, so the breakthrough from the axial dimensions of the flexible gear 10a and the rigid gear 60a is difficult; at point 4, the roller bearing 70a is a direct part for transmitting power to the output shaft 80a, and the structural strength thereof needs to be satisfied, and no substantial breakthrough is made in the size of the roller bearing 70 a.

So for many years, no more miniaturized product appears on the market. However, the applicant has consumed great research and development costs to perform the technical research, breaks through the original structural schemes (as shown in fig. 2) of the cup-shaped flexspline 10a, the sleeve 21a, the first positioning bearing 30a and the second positioning bearing 40a, innovatively proposes a brand-new structural scheme, and enables the harmonic reducer 100a to be more miniaturized on the basis of the original smaller scheme. In the further miniaturization of the harmonic reducer 100a, the joint to which this harmonic reducer 100a is applied is also further miniaturized, and at the same time, the robot to which this joint is applied is also further miniaturized.

The following describes in more detail the specific implementation of the present invention in connection with specific embodiments:

Referring to fig. 3 and 4, an embodiment of the present invention provides a robot 200, which includes a base 203 and a mechanical arm 201 connected to the base 203, wherein the mechanical arm 201 includes at least two arm bodies 202 and a joint 204 connected between the arm bodies 202, and the movement of the mechanical arm 201 is realized through the joint 204.

Referring to fig. 5 and 6, the joint 204 includes a motor 9 and a harmonic reducer device 100b coupled to the motor 9. Fig. 5 and 6 show a harmonic reducer device 100b provided in a first embodiment of the present invention.

The harmonic reducer device 100b includes a cup-shaped flexspline 10b, a rigid spline 60b engaged with the flexspline 10b, and a wave generator 20b. The wave generator 20b includes a sleeve 21b for power input and a wave generator body 22b provided on the sleeve 21b and radially deforming the flexspline 10b by rotation of the sleeve 21b to change the meshing position of the flexspline 10b with the rigid spline 60 b.

The harmonic reducer device 100b also includes an oppositely disposed end cap 90b and output bearing 70b. The harmonic reducer device 100b further comprises a first stop structure 30b and a second stop structure 40b that stop the sleeve 21 b. The first stop structure 30b is a non-bearing structure and is sleeved on the sleeve 21 b.

The axial dimension of the first stop structure 30b is smaller than that of a conventional bearing providing an axial stop function, for example, the axial dimension of the first stop structure 30b is smaller than that of the first positioning bearing 30a shown in fig. 2.

The harmonic reducer device 100b in this embodiment breaks through the convention, and the first stopper structure 30b does not adopt a bearing structure, but adopts a first stopper structure 30b smaller than the axial dimension of the conventional bearing providing the axial limit function, instead of the conventional bearing, which makes an innovative break through in the reduction of the axial dimension. Because the balls are needed to be added between the inner ring and the outer ring of the existing bearing, in order to ensure that the balls can safely and reliably run between the inner ring and the outer ring, the axial dimension of the inner ring and the outer ring cannot be made small, and the invention directly breaks through the use of the conventional bearing, and changes the first stop structure 30b with the axial dimension smaller than that of the conventional bearing, under the condition that the radial dimension of the rigid wheel 60b is unchanged, the axial dimension of the harmonic reducer device 100b is directly changed, so that the requirement of more miniaturization of the harmonic reducer device 100b is met, and the market requirement is met. It should be noted that the conventional bearing may be the first positioning bearing 30a shown in fig. 2.

Referring to fig. 7, fig. 7 shows a comparison of the axial dimension of the harmonic reducer device 100b provided by the embodiment of the present invention and the axial dimension of the harmonic reducer 100a of fig. 2, it can be seen from the figure that, with the same radial dimension L of the rigid gear 60b, the axial dimension is significantly reduced, specifically, the axial dimension of the harmonic reducer device 100b provided by the embodiment of the present invention is significantly reduced compared with the axial dimension of the harmonic reducer 100a of fig. 2, based on the line W, by taking the element that has the limiting function on the left side of the first stop structure 30b as the starting point (in fig. 2, starting point is the fixing plate 52a, in fig. 7, starting point is the left side of the shroud 91b itself), and the cup bottom 12b of the flexspline 10b as the ending point. In this embodiment, a specific reduction of 5mm-13mm is achieved. Preferably 8mm-10mm is reduced.

Referring again to fig. 5 and 6, a gap (not shown) is formed between the sleeve 21b and the end cap 90 b. The first stopper structure 30b seals the slit.

In the present embodiment, the first stopper structure 30b and the second stopper structure 40b perform axial bidirectional stopper on the sleeve 21 b.

The outer circumferential surface of the sleeve 21b is formed with a first step 23b. The outside surface of the end cap 90b is formed with a shroud 91b. The first stopper structure 30b is provided between the first step 23b and the shroud 91b. The first stopper structure 30b restricts its bi-directional movement in the axial direction of the sleeve 21b by 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 stopper structure 30b by the sleeve 21 b. In other embodiments, the first step 23b may be formed by increasing the diameter of the sleeve 21b on the right side of the sleeve 21b at a position corresponding to the first stopper structure 30b, where "right side" refers to the side of the first stopper structure 30b near the wave generator body 22 b.

In this embodiment, the first stopping structure 30b includes a stopping member 31b sleeved on the sleeve 21b and rotating along with the rotation of the sleeve 21b, and a sealing member 32b rotating relative to the stopping member 31b, wherein the sealing member 32b is fixedly connected with the end cover 90b, the stopping member 31b abuts against the first step 23b, and the sealing member 32b abuts against the enclosing plate 91 b. By replacing the bearing arrangement with two relatively rotating stops 31b and seals 32b, a smaller axial dimension can be achieved without interfering with the rotation of the sleeve 21b relative to the end cap 90 b.

A revolute pair between the stopper 31b and the seal 32b is formed at a portion overlapping between the outside of the stopper 31b and the inside of the seal 32 b. Here, the outside of the stopper 31b means a side away from the wave generator main body 22b, and the inside of the seal 32b means a side close to the wave generator main body 22 b.

The projections of the seal 32b and the stop 31b in a direction parallel to the axis of the sleeve 21b at least partially overlap. A revolute pair of the first stopper structure 30b is formed at the overlapped portion.

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 21 b. The seal 32b is fixedly connected to the end cap 90b such that the stopper 31b serves as a rotor and the seal 32b serves as a stator.

In the present embodiment, the first stopper structure 30b is composed of the stopper 31b and the seal 32b, and the first stopper structure 30b is composed of only two parts, which is one less part in terms of the number of parts than the conventional bearing, specifically, the conventional bearing is composed of an inner ring, an outer ring, and balls disposed between the inner ring and the outer ring, and three parts, whereas the first stopper structure 30b in the present invention is composed of only two parts, namely, the stopper 31b and the seal 32b. The invention has great breakthrough in material cost reduction caused by part reduction.

In the present embodiment, the axial dimension of the first stopper structure 30b is smaller than the difference between the inner diameter and the outer diameter of the first stopper structure 30 b. The harmonic reducer device 100b in this embodiment breaks through the convention, the first stop structure 30b does not adopt a bearing structure, but adopts the first stop structure 30b with an axial dimension smaller than the difference between the inner diameter and the outer diameter instead of the conventional bearing, and an innovative break through in the reduction of the axial dimension is achieved. Because the balls are required to be added between the inner ring and the outer ring of the existing bearing, in order to ensure that the balls run safely and reliably between the inner ring and the outer ring, the axial dimension of the inner ring and the outer ring cannot be made small, and the axial dimension of the inner ring or the outer ring is generally equal to or larger than the difference between the inner diameter and the outer diameter of the bearing, and the difference between the inner diameter and the outer diameter of the bearing refers to the diameter difference or the radius difference between the inner ring and the outer ring. The invention directly breaks through the use of the conventional abandoned bearing, and changes the structure that the axial dimension is smaller than the difference between the inner diameter and the outer diameter, and under the condition that the radial dimension of the rigid wheel 60b is unchanged, the requirement of more miniaturization of the harmonic reducer device 100b is met by directly changing the axial dimension of the harmonic reducer device 100b, thereby meeting the market requirement.

In the present embodiment, a seal structure 33b is formed between the stopper 31b and the seal 32b, so as to achieve a sealing effect and prevent leakage of lubricating oil from the inner cavity of the harmonic reducer device 100 b.

In the present embodiment, the sealing structure 33b includes a ring groove 34b and a convex ring 35b inserted into the ring groove 34b, one of the stopper 31b and the sealing member 32b is provided with the ring groove 34b, and the other of the stopper 31b and the sealing member 32b is provided with the convex ring 35b. By the engagement of the annular groove 34b with the convex ring 35b, not only does the relative rotation between the stopper 31b and the seal 32b not be hindered, but also the pair of rotation between the stopper 31b and the seal 32b provides a sealing function. The specific sealing effect is achieved by the labyrinth mating surfaces of the ring groove 34b and the convex ring 35b.

Referring to fig. 8 and 9, in the present embodiment, at least three matching surfaces of the ring groove 34b and the convex ring 35b include two groove wall surfaces 36b and a groove bottom surface 37b connecting the two groove wall surfaces 36 b. A corner 38b is formed between the groove bottom surface 37b and each groove wall surface 36 b. The arrangement is such that even if the lubricant were to flow out, it would have to pass through the two groove wall surfaces 36b, one groove bottom surface 37b and the two corners 38b, and this lengthy path would eventually prevent the lubricant from flowing out, achieving the purpose of sealing and leakage prevention.

The axial dimension between the stopper 31b and the seal 32b is further reduced by the mating arrangement of the annular groove 34b and the collar 35 b. Meanwhile, the stopper 31b has a certain supporting effect on the seal 32b by the cooperation of the annular groove 34b and the convex ring 35b, and of course, the stopper 31b also has a certain supporting effect on the end cover 90b by the seal 32 b.

The annular groove 34b and the convex ring 35b are provided in pairs, and may be provided in one pair, two pairs, three or more pairs, or the like. The number of pairs is specifically set according to the radial dimension difference between the end cap 90b and the sleeve 21b, and the thickness of the convex ring 35b, where the radial dimension difference between the end cap 90b and the sleeve 21b refers to the radial distance between the end cap 90b and the sleeve 21b, and specifically the radial distance between the body 92b of the end cap 90b and the sleeve 21 b. In the present embodiment, the ring groove 34b and the convex ring 35b are provided in two pairs.

At least one of the stopper 31b and the seal 32b is in a sheet shape. As used herein, sheet-like means having an axial dimension less than the difference between the inner and outer diameters. In the present embodiment, the stopper 31b and the seal 32b are both sheet-shaped, 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 32 b. In other embodiments, one of the stopper 31b and the seal 32b may be selected to be provided in a sheet-like structure.

The end cap 90b includes a main body 92b, and the 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 as referred to herein is the end surface of the main body 92b that is adjacent to the output bearing 70b. An annular cavity is formed between the inner end surface of the main body 92b and the outer race of the output bearing 70b, and the rigid wheel 60b is disposed within the annular cavity and sandwiched between the inner end surface of the main body 92b and the outer race of the output bearing 70b. The main body 92b, the rigid wheel 60b and the outer race of the output bearing 70b are fixed together by the first fixing piece 61 b.

In the present embodiment, the shroud 91b is attached to the outer end edge of the main body 92b and is integral with the main body 92 b. That is, the shroud 91b does not exist as a separate component but is integral with the main body 92b of the end cover 90b, and thus the number of components can be reduced, the additional processing cost of the shroud 91b as a separate component can be reduced, and the processing and assembly steps for the shroud 91b as a separate component can be reduced, which saves the cost of the harmonic reducer device 100b to some extent. Referring again to fig. 2, the component serving as the shroud 91b is a fixed plate 52a on the outside of the first end cap 50a, and the fixed plate 52a, which is shown as a separate component in fig. 2, adds virtually to the number of components, also requires increased inventory space, increases inventory management types of components, and increases manufacturing and assembly processes, and of course, increases costs.

In this embodiment, the flexspline 10b is cup-shaped and includes a ring portion 11b and a cup bottom portion 12b connected to the ring portion 11 b. The cup bottom 12b is formed by an end edge of the ring portion 11b extending inward. The cup bottom 12b is provided with a through hole (not shown) for the output shaft 80b to pass through. The outer circumferential surface of the ring portion 11b is provided with an external gear (not shown) for meshing with an internal gear (not shown) of the rigid gear 60 b. The ring portion 11b and the cup bottom portion 12b are formed with an accommodation space 14b, and the wave generator main body 22b and the second stopper structure 40b are located in the accommodation space 14b.

The rigid gear 60b is ring-shaped, has an internal gear formed on the inner side thereof, and meshes with the flexible gear 10 b. The flexspline 10b is disposed in the cavity of the rigid spline 60 b.

In the present embodiment, the second stop structure 40b is a stop bearing 40b, and the power output end of the wave generator 20b at least partially overlaps with the projection of the stop bearing 40b on the axis of the sleeve 21 b. So configured, the overall axial dimensions of the stop bearing 40b and the power output of the wave generator 20b are reduced, and referring again to fig. 2, the power output of the wave generator 20a in the harmonic reducer 100a shown in fig. 2 is completely free from overlap with the projection of the second positioning bearing 40a on the axis of the sleeve 21 a. In the present invention, the power output end of the wave generator 20b overlaps with the projection of the stopper bearing 40b on the axis of the sleeve 21b, and the dimension in the axial direction of the sleeve 21b is smaller. While the consistent design of the industry in a harmonic reducer is that two stop bearings 30a, 40a are arranged on opposite sides of the power output end of the wave generator 20a as shown in fig. 2, and there is no overlap, the invention breaks the convention, creatively improves the structural position relationship between the stop bearing 40b and the power output end of the wave generator 20b, so that the projections of the power output end of the wave generator 20b and the stop bearing 40b on the axis of the sleeve 21b at least partially overlap, further reduces the axial dimension of the harmonic reducer device 100b, and further contributes to the miniaturization development of the harmonic reducer device 100 b.

In the present embodiment, the projection overlap ratio of the power output end of the wave generator 20b and the stopper bearing 40b on the axis of the sleeve 21b is in the range of 0.1-1. Specifically, the projection overlap ratio may be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9. The projection overlap ratio referred to herein means that, on a cross section parallel to the axial direction of the sleeve 21b, it is defined that: the axial length of the stop bearing 40b which coincides with the projection of the power output end of the wave generator 20b on the axis of the sleeve 21 b; b 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; where c=a/B, i.e. the projection overlap ratio C is equal to the ratio of a to B.

Preferably, the projection overlap ratio of the power output end of the wave generator and the stop bearing on the axis of the sleeve ranges from 0.5 to 0.9.

Under the guidance of the idea of overlapping the power output end of the wave generator 20b with the projection of the stop bearing 40b on the axis of the sleeve 21b, research and testing are continuously conducted, and finished products are designed, and tests, and it is unexpectedly found in a large number of samples that "the overlapping ratio of the power output end of the wave generator with the projection of the stop bearing on the axis of the sleeve ranges from 0.5 to 0.9", not only can make a larger contribution in the axial dimension, but also can be well ensured in the reliability of the product.

The inner annular 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 flexspline 10 b. The second step 24b is formed by increasing the inner diameter of the sleeve 21b at a position corresponding to the second stopper structure 40b by the sleeve 21 b.

The harmonic reducer device 100b further includes an output shaft 80b fixedly coupled to the inner race 72b of the output bearing 70b, with the stop bearing 40b positioned between the output shaft 80b and the sleeve 21b. In designing the harmonic reducer device 100b, the inertia thinking is that the stop bearing 40b is arranged at the periphery of the sleeve 21b, and the stop bearing 40b is not thought to be arranged between the sleeve 21b and the output shaft 80b, but the invention provides a brand new design thought, namely, the stop bearing 40b is directly arranged between the sleeve 21b and the output shaft 80b, and meanwhile, the stop bearing 40b extends below the power output end of the wave generator 20b, and the sleeve 21b is arranged between the stop bearing 40b and the power output end of the wave generator 20 b. The sleeve 21b and the output shaft 80b radially limit the stop bearing 40b without additional limiting structures.

The harmonic reducer device 100b further includes a washer 81b disposed between the cup bottom 12b of the flexspline 10b and the stop bearing 40 b. The gasket 81b has a sheet shape. The washer 81b and the second step 24b axially bi-directionally limit the stopper bearing 40b, and the sleeve 21b and the output shaft 80b radially limit the stopper bearing 40b, whereby the stopper bearing 40b is limited in both the axial direction and the radial direction.

The washer 81b is in a sheet shape, the washer 81b and the stopper bearing 40b do not overlap in the axial direction of the sleeve 21b, and the washer 81b and the stopper bearing 40b are fitted on the sleeve 21b side by side. Referring again to fig. 2, the washer 81a in fig. 2 includes a radial connection portion 82a and an axial ring portion 83a, and the radial connection portion 82a is used to radially limit the stop bearing 40b, so that in the present invention, the washer 81b only needs to be simple and sheet-shaped, and the radial connection portion 82a is not needed, so that the structure is simpler and the assembly is easy.

The outer ring surface of the output shaft 80b is 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 portion 12b of the flexspline 10 b. In the axial direction of the sleeve 21b, the stopper bearing 40b, the washer 81b, the cup bottom 12b of the flexspline 10b, the mounting portion 82b, and the inner ring 72b of the output bearing 70b are arranged in close order, and no other component is provided therebetween. 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 mounted in the receiving groove 73 b.

The harmonic reducer device 100b further includes another end cap 93b located outside of the output bearing 70b, the other end cap 93b being connected to the inner race 72b of the output bearing 70 b. The outer side of the output bearing 70b as referred to herein refers to the side of the output bearing 70b facing away from the rigid wheel 60 b.

The other end cap 93b is two separate pieces from the output shaft 80 b. A harness structure 1b is provided between one side of the other end cap 93b and the output shaft 80 b. The other end cover 93b and the output shaft 80b are provided as two independent components, on one hand, the inconvenience of processing and installation caused by the integral structure of the output shaft 80a and the second end cover 93a shown in fig. 2 is reduced, and meanwhile, the cost is also reduced, and on the other hand, a wire harness structure 1b can be arranged between the other end cover 93b and the end part of the output shaft 80b, so that two purposes are achieved.

The other end cap 93b is provided with a connecting portion 94b protruding on a side close to the output bearing 70b, and the connecting portion 94b extends into the inner race 72b of the output bearing 70b and is close to the end of the output shaft 80 b. In the present embodiment, the wire harness structure 1b includes a tube body 101b connected to the inside of the connection portion 94b and an elastic expansion portion 102b sleeved outside the tube body 101 b. The tube 101b is provided for the cable 103b to pass through. One end of the pipe body 101b extends into the output shaft 80b, and the other end is connected to the connection portion 94 b. The expansion and contraction portion 102b is located between the pipe body 101b and the connection portion 94 b.

In the present embodiment, the wave generator main body 22b includes an elliptical disk 25b formed on the sleeve 21b and a flexible bearing 26b connected to the elliptical disk 25 b. In other embodiments, the wave generator body 22b includes a rotating arm formed on the sleeve 21b and rollers mounted 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.

In this embodiment, the output bearing 70b is a bearing with an oil seal 95b, and the harmonic reducer as shown in fig. 2 does not need to be provided with the oil seal 95a on the inner side of the second end cover 93a, and the oil seal 95a provided on the inner side of the second end cover 93a needs to be customized, which is relatively high in cost.

In summary, the harmonic reducer device 100b of the present invention is reduced in cost by approximately 20% from the harmonic reducer device 100a shown in fig. 2. The concrete steps are as follows:

1. The rigid gear 60a and the flexible gear 10a of the harmonic reducer 100a shown in fig. 2 need to be customized, while the harmonic reducer device 100b of the invention can meet the design requirement by only adopting standard components of the rigid gear 60b and the flexible gear 10b, thereby reducing the customization cost;

2. The roller bearing 70a of the harmonic reducer 100a shown in fig. 2 adopts a bearing without an oil seal, the oil seal is customized and designed between the right end cover 93a and the roller bearing 70a, and the invention adopts an output bearing 70b with an oil seal 95b, so that additional design is not needed, and the customization cost is reduced;

3. The harmonic reducer 100a shown in fig. 2, the member functioning as the shroud 91b is the fixed plate 52a on the outside of the first end cap 50a, and this fixed plate 52a, which is present as a separate member in fig. 2, adds virtually to the number of parts, also requires an increase in the stock space, increases the sort of stock control of the parts, and also increases the processing and assembly steps, and of course, increases the cost, while the shroud 91b is attached to the outer end edge of the main body 92b and is integral with the main body 92 b. The shroud 91b does not exist as a separate component but is integral with the main body 92b of the end cap 90b, so that the number of components can be reduced, the additional processing cost of the shroud 91b as a separate component is reduced, the processing procedure and the assembly procedure of the shroud 91b as a separate component are also reduced, and the cost of the harmonic reducer device 100b is saved to a certain extent;

4. While the harmonic reducer 100a shown in fig. 2 has the output shaft 80a integrally formed with the right end cap 93a, the entire part volume is large, the right end cap 93a is almost perpendicular to the output shaft 80a, and the processing cost is virtually increased in terms of processing difficulty, whereas the output shaft 80b is separated from the other end cap 93b, and the output shaft 80b is processed separately from the other end cap 93b in the processing, although the number of the processing parts is increased, the processing cost is actually increased compared with the processing difficulty, and the cost is actually reduced.

The joint 204 further includes a drive motor 9 that performs power input to the sleeve 21 b. The drive motor 9 is provided on one side of the harmonic reducer device 100 b. The joint 204 further comprises another bearing 101 sleeved on the sleeve 21b, and the driving motor 9 comprises 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 remote from the wave generator 20 b. The other bearing 101 is located on the side of the rotor 91 remote from the other end cap 93 b.

The joint 204 further includes a mounting member 206 that fits over the sleeve 21 b. The mounting 206 is located on the side of the motor 9 remote from the end cap 90b and serves to limit the other bearing 101.

A receiving 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 receiving space 93 and does not occupy the axial space of the knuckle 204. The mounting member 206 includes a plate 207 and a retainer ring 208 coupled to one side of the plate 207. The stop ring 208 and sleeve 21b radially stop the other bearing 101. The outer circumferential surface of the sleeve 21b is formed with a third step 27b. The third step 27b and the plate 207 axially limit the other bearing 101. The limiting ring 208 extends into the accommodating space 93. An elastic member 95 is arranged between the other bearing 101 and the plate 207 to play a role in shock absorption.

The joint 204 further includes a brake 205 mounted to the sleeve 21 b. The stopper 205 is located outside the mount 206. The mount 206 is located between the brake 205 and the motor 9. The outer peripheral portion 2b of the attachment 206 is interposed between the housing 94 of the motor 9 and the housing 209 of the brake 205, and the attachment 206 is fixed.

The mounting member 206 utilizes the existing gap between the motor and the brake to mount the other bearing 101, and the outer peripheral portion 2b of the mounting member 206 is connected in a staggered manner between the housing 94 of the motor 9 and the housing 209 of the brake 205 by extending the stop collar 208 into the accommodating space 93 of the motor 9, so that the axial dimension of the entire joint is not increased.

In summary, the harmonic reducer device 100b is reduced in axial dimension, and the requirement for further miniaturization of the harmonic reducer device 100b is achieved without changing the radial dimension of the rigid wheel 60b, and at the same time, the joint 204 to which the harmonic reducer device 100b is applied is also further miniaturized. Further, the robot arm 201 to which such a miniaturized joint is applied is also miniaturized. The robot 200 to which such a robot arm is applied is also more miniaturized.

Referring to fig. 10 and 11, a harmonic reducer device 100c according to a second embodiment of the present invention is substantially the same as the harmonic reducer device 100b according to the first embodiment, except that:

The first stopping structure 30c comprises a stopping piece 31c sleeved on the sleeve 21c and rotating along with the rotation of the sleeve 21c, and a sealing piece 32c connected with the stopping piece 31 c; one end inner side surface of the stop piece 31c abuts against the first step 23c, and one end outer side surface of the sealing piece 32c abuts against the coaming 91c, so that limiting of the first stop structure 30c between the first step 23c and the coaming 91c is achieved. The inner side surface here means a side closer to the wave generator main body 22c, and the outer side surface means a side farther from the wave generator main body 22 c. The end of the stopper 31c is referred to herein as the end close to the sleeve 21c, and the end of the seal 32c is referred to as the end close to the shroud 91c and away from the sleeve 21 c.

The first stopper structure 30c is entirely sheet-shaped. The overall axial dimension of the first stop structure 30c is less than the difference between the inner and outer diameters of the first stop structure 30 c. The seal 32c rotates together with the stopper 31c along with the sleeve 21 c. A revolute pair is formed between the seal 32c and the shroud 91c, and when the sleeve 21c rotates, one end outer edge of the seal 32c contacts the shroud 91c to form a revolute pair. The outer edge of one end of the seal 32c is always in contact with the shroud 91c when the seal 32c rotates, and a seal structure is formed at the contact between the seal 32c and the shroud 91 c.

The stopper 31c is annular. The stopper 31c includes a fixing portion 301c having a U-shaped cross section, an extending portion 302c extending from a side of the fixing portion 301c close to the wave generator main body 22c away from the sleeve 21c direction, and an inclined portion 303c extending obliquely from a side edge of the extending portion 302c away from the sleeve 21c direction and toward the shroud 91 c.

The seal 32c is annular. The seal 32c includes a stopper 320c fixed in the fixing portion 301c and a contact portion 321c extending obliquely toward the shroud 91c from a side of the stopper 320c facing away from the sleeve 21c and close to the shroud 91 c. The contact portion 321c forms an obtuse angle with the stop portion 320 c.

The stopper 31c is a rigid member, and the seal 32c is a flexible member. When the first stop structure 30c rotates along with the sleeve 21c, the contact portion 321c and the coaming 91c are always in tight contact in a pressing mode, so that the limiting effect is achieved, and the sealing effect is also achieved.

Referring to fig. 12 and 13, a harmonic reducer device 100d according to a third embodiment of the present invention is substantially the same as the harmonic reducer device 100b according to the first embodiment, except that:

the first stopping structure 30d sleeved on the sleeve 21d is directly formed on the end cover 90d, so that an axial stopping function is not realized through separate parts, and the number of parts is reduced.

In the third embodiment, the first stopper structure 30d is formed directly on the shroud 91 d. The first step is no longer needed for stopping. The first stopper structure 30d includes a connection ring 92d connected to a side of the shroud 91d near the sleeve 21d, the connection ring 92d being in surface contact with an outer circumferential surface of the sleeve 21 d.

A seal structure 33d is formed between the connection ring 92d and the outer annular surface of the sleeve 21 d. The sealing structure 33d is provided with a ring groove 34d on the contact surface between the connecting ring 92d and the sleeve 21 d. The ring groove 34d includes two groove wall surfaces 36d and a groove bottom surface 37d connecting the two groove wall surfaces 36 d. A corner 38d is formed between the groove bottom surface 37d and each groove wall surface 36 d. The arrangement is such that even if the lubricant were to flow out, it would have to pass through the two groove wall surfaces 36d, one groove bottom surface 37d and the two corners 38d, and this lengthy path would eventually prevent the lubricant from flowing out, achieving the purpose of sealing and leakage prevention.

The annular grooves 34d may be provided in plural, for example, 1,2,3, etc., and in the case of downsizing the axial direction, the number of the annular grooves 34d may be set according to circumstances.

In the present embodiment, the use of the first positioning bearing 30a of the harmonic reducer 100a shown in fig. 2 is eliminated, and the dimension of the first stopper structure 30d in the axial direction is smaller than the sum of the axial dimensions of the fixed plate 52a and the first positioning bearing 30a of the harmonic reducer 100a shown in fig. 2.

In this embodiment, the connection ring 92d may extend toward the motor 9 d. It will be appreciated that, in order to reduce the axial dimensions even further, the connection ring 92d may extend into the accommodation space 93d between the stator 92d and the rotor 91d of the electric motor 9 d.

Referring to fig. 14, fig. 14 shows a comparison between the harmonic reducer device 100d provided by the third embodiment of the present invention and the harmonic reducer 100a of fig. 2 in the axial dimension, it can be seen that, with the same radial dimension L of the rigid wheels 60d, 60a, the axial dimension is significantly reduced, specifically, the axial dimension of the harmonic reducer device 100d provided by the embodiment of the present invention is significantly reduced compared with the axial dimension of the harmonic reducer 100a of fig. 2, based on the line W, starting from the element that serves as a limit function for the left side of the first stop structure 30d (starting from the fixed plate 52a in fig. 2, starting from the left side of the first stop structure 30d in fig. 14), and ending from the cup bottom 12d of the flexspline. In this embodiment, a specific reduction of 5mm-13mm is achieved. Preferably 8mm-10mm is reduced.

In the first, second and third examples, three different solutions of the first stop structure are provided, and in other embodiments, the first stop structure may be another support structure such as a sleeve.

In the present embodiment, the concept of the stopper means blocking, and the stopper does not necessarily have to be in contact all the time, and may function as a stopper when the stopper is required to be blocked in the moving direction. In other embodiments, the stop may function as a seal and/or a detent, meaning a detent.

Referring to fig. 15, a harmonic reducer device 100e according to a fourth embodiment of the present invention is substantially the same as the harmonic reducer device 100b according to the first embodiment, and is different from the first embodiment in that:

the other end cap 93e is integral with the output shaft 80 e. The mounting portion 82b is not provided on the output shaft 80e, and the receiving groove 73b is not required for the inner race 72e of the output bearing 70 e. The cup bottom 12e of the flexspline 10e is directly secured to the inner race 72e of the output bearing 70 e. The mounting portion 82b is no longer provided between the cup bottom 12e of the flexspline 10e and the inner race 72e of the output bearing 70 e. The cup bottom 12e of the flexspline 10e is in direct contact with the inner race 72e of the output bearing 70 e. The fixation of the output shaft 80e to the inner ring 72e of the output bearing 70e is achieved by fixation of the other end cap 93e to the inner ring 72e of the output bearing 70 e.

Referring to fig. 16, a harmonic reducer device 100f according to a fifth embodiment of the present invention is substantially the same as the harmonic reducer device 100c according to the second embodiment, except that a harmonic reducer device 100e according to a fourth embodiment of the present invention is the same as the harmonic reducer device 100b according to the first embodiment, i.e. the other end cap 93f is integral with the output shaft 80 f. The output shaft 80f is not provided with a mounting portion, and the inner ring 72f of the output bearing 70f is not provided with a receiving groove. The cup bottom 12f of the flexspline 10f is directly fixed with the inner race 72f of the output bearing 70 f. No mounting portion is provided between the cup bottom 12f of the flexspline 10f and the inner ring 72f of the output bearing 70 f. The cup bottom 12f of the flexspline 10f is in direct contact with the inner race 72f of the output bearing 70 f. The fixation of the output shaft 80f to the inner race 72f of the output bearing 70f is achieved by the fixation of the other end cap 93f to the inner race 72f of the output bearing 70 f.

Referring to fig. 17, a harmonic reducer device 100g according to a sixth embodiment of the present invention is substantially the same as the harmonic reducer device 100d according to the third embodiment, except that a harmonic reducer device 100e according to a fourth embodiment of the present invention is the same as the harmonic reducer device 100b according to the first embodiment, that is, the other end cap 93g is integral with the output shaft 80 g. The output shaft 80g is not provided with a mounting portion, and the inner ring 72g of the output bearing 70g is not provided with a receiving groove. The cup bottom 12g of the flexspline 10g is directly fixed with the inner race 72g of the output bearing 70 g. No mounting portion is provided between the cup bottom 12g of the flexspline 10g and the inner ring 72g of the output bearing 70 g. The cup bottom 12g of the flexspline 10g is in direct contact with the inner race 72g of the output bearing 70 g. The fixation of the output shaft 80g to the inner ring 72g of the output bearing 70g is achieved by the fixation of the other end cap 93g to the inner ring 72g of the output bearing 70 g.

In the first to sixth embodiments described above, at least 2 contributing to the reduction of the axial dimension of the harmonic reducer device, specifically:

1. The first stopper structure adopts the first stopper structures 30b, 30c, 30d described in the above embodiments instead of the bearing structure, and the axial dimension thereof is made smaller than that of the conventional bearing by the structural design of the first stopper structures 30b, 30c, 30 d.

2. The power take-off of the wave generator at least partially overlaps the projection of the second stop structure on the axis of the sleeve.

It will be appreciated that in other embodiments, the harmonic reducer arrangement is considered to be modified at point 2, but not at point 1, as is the case with the bearing arrangement. Specifically, reference may be made to the seventh embodiment, the eighth embodiment and the ninth embodiment in the following description.

Referring to fig. 18, a seventh embodiment of the present invention provides a harmonic reducer device 100h substantially identical to the harmonic reducer device 100b provided in the first embodiment, except that:

Unlike the first embodiment, there is no need to provide another bearing 101 between the brake 205 and the motor 9, and of course there is no need to provide a mount 206, but the first stopper structure 30h adopts a bearing structure. Specifically, a stopper bearing 30h is provided between the shroud 91h and the first step 23 h.

Further, an elastic member 95h is provided between the stopper bearing 30h and the shroud 91h, and functions as a damper.

Further, the shroud 91h extends into a receiving space 93h formed between the stator 92h and the rotor 94h of the motor 9 h. To reduce the axial dimension even further.

Referring to fig. 19, an eighth embodiment of the present invention provides a harmonic reducer device 100i substantially identical to the harmonic reducer device 100h provided by the seventh embodiment, except that:

The other end cap 93i is integral with the output shaft 80 i. The output shaft 80i is not provided with a mounting portion, and the inner ring 72i of the output bearing 70i is not provided with a receiving groove. The cup bottom 12i of the flexspline 10i is directly fixed with the inner race 72i of the output bearing 70 i. No mounting portion is provided between the cup bottom 12i of the flexspline 10i and the inner ring 72i of the output bearing 70 i. The cup bottom 12i of the flexspline 10i is in direct contact with the inner race 72i of the output bearing 70 i. The fixation of the output shaft 80i to the inner ring 72i of the output bearing 70i is achieved by the fixation of the other end cap 93i to the inner ring 72i of the output bearing 70 i.

Referring to fig. 20, a ninth embodiment of the present invention provides a harmonic reducer device 100k substantially identical to the harmonic reducer device 100b provided in the first embodiment, except that:

the first stopper structure 30k adopts a bearing structure, and the shroud 91b of the first embodiment is not provided; the end cap 90k protrudes through a protruding ring portion 910k into the accommodation space 98k formed between the stator 92k and the rotor 91k of the motor 9 k.

The first stop structure 30k is located within the raised ring portion 910 k. A retainer ring 920k is provided between the first stopper structure 30k and the rotor 91k of the motor 9 k. The first stopper structure 30k is located between the first step 23k and the retainer ring 920k at the upper limit of the sleeve 21k in the axial direction. The first stop structure 30k is located between the raised ring portion 910k and the output shaft 80k at the upper limit of the sleeve 21k in the radial direction.

The first stop structure 30k extends between the stator 92k and the rotor 91 k. The second stop structure 40k replaces the bearing with a seal 40k. The seal 40k is interposed between the inner annular surface of the sleeve 21k and the output shaft 80 k. The seal 40k is in surface contact with the output shaft 80 k. A sealing structure is formed at the contact surface. The seal structure includes at least one ring groove 34k open on the contact surface of the seal 40k. In the present embodiment, the number of the ring grooves 34k is plural, and a labyrinth seal structure is formed on the contact surface.

One side of the seal 40k abuts against the second step 24k and the other side indirectly or directly abuts against the cup bottom 12k of the flexspline 10 k. A gasket (not shown) may be provided between the seal 40k and the cup bottom 12k of the flexspline 10k so that the other side of the seal 40k abuts the cup bottom 12k of the flexspline 10k through the gasket.

The first stop structure 30k and the further bearing 101k are both located on the same side of the wave generator body 22 k.

In the ninth embodiment, the output shaft 80k is provided separately from the other end cap 93k as in the first embodiment, and in other embodiments, the output shaft 80k and the other end cap 93k may be integral as in the fourth embodiment.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, or alternatives falling within the spirit and principles of the invention.

Claims

1. A harmonic reducer device, characterized by: the harmonic reducer device comprises a cup-shaped flexible gear, a rigid gear meshed with the flexible gear and a wave generator, the flexible gear comprises a ring part and a cup bottom connected with the ring part, the cup bottom is formed by extending inwards from one end edge of the ring part, the wave generator comprises a sleeve for power input and a wave generator main body which is arranged on the sleeve and enables the flexible gear to radially deform under the rotation of the sleeve so as to change the meshing position of the flexible gear and the rigid gear, the harmonic reducer device also comprises an end cover and an output bearing which are oppositely arranged, the harmonic reducer device also comprises a first stop structure and a second stop structure, the first stop structure and the second stop structure are used for stopping the sleeve, and the projection of a power output end of the wave generator and the second stop structure on the axis of the sleeve is at least partially overlapped; the outer ring surface of the sleeve is provided with a first step, the outer side surface of the end cover is provided with a coaming, the first stop structure is arranged between the first step and the coaming, the sleeve is also sleeved with a motor, the motor comprises a rotor sleeved on the sleeve and a stator matched with the rotor, a containing space is formed between the stator and the rotor, the coaming stretches into the containing space of the motor, and the first stop structure is arranged between the coaming and the sleeve; the first stop structure comprises a stop piece sleeved on the sleeve and rotating along with the rotation of the sleeve and a sealing piece connected with the stop piece; one end inner side surface of the stop piece is propped against the first step, and one end outer side surface of the sealing piece is propped against the coaming; the sealing element is always contacted with the coaming when the sealing element rotates, and a sealing structure is formed at the contact position between the sealing element and the coaming; the sealing element comprises a stop part fixed in the fixing part and a contact part, wherein the stop part is fixed in the fixing part, the contact part is formed by the stop part, the contact part is away from the sleeve and is close to one side of the coaming, the contact part extends towards the coaming in an inclined mode, and the contact part is in contact with the coaming.

2. A harmonic reducer apparatus as claimed in claim 1, wherein: the projection overlapping ratio of the power output end of the wave generator and the second stop structure on the axis of the sleeve ranges from 0.1 to 1.

3. A harmonic reducer apparatus as claimed in claim 1, wherein: the projection overlap ratio of the power output end of the wave generator and the second stop structure on the axis of the sleeve ranges from 0.5 to 0.9.

4. A harmonic reducer apparatus as claimed in claim 1, wherein: and the second stop structure is a stop bearing.

5. A harmonic reducer apparatus as claimed in claim 1, wherein: the harmonic reducer device further comprises an output shaft fixedly connected with the inner ring of the output bearing, and the second stop structure is located between the output shaft and the sleeve.

6. A harmonic reducer apparatus as claimed in claim 1, wherein: a gap is formed between the sleeve and the end cover, and the first stop structure seals the gap.

7. A harmonic reducer apparatus as claimed in claim 1, wherein: the axial dimension of the first stop structure is less than the difference between the inner and outer diameters of the first stop structure.

8. A harmonic reducer apparatus as claimed in claim 1, wherein: the first stop structure and the second stop structure perform axial bidirectional stop on the sleeve.

9. A harmonic reducer unit as claimed in any one of claims 1 to 8, wherein: the rigid wheel is fixed between the inner end surface of the main body and the outer ring of the output bearing, and the coaming is connected to the outer end edge of the main body and is integrated with the main body.

10. The harmonic reducer apparatus of claim 5 wherein: the outer ring surface of the output shaft is convexly provided with a mounting part, and the mounting part and the cup bottom of the flexible gear are fixed on the inner ring of the output bearing together.

11. The harmonic reducer apparatus of claim 4 wherein: the inner annular surface of the sleeve is provided with a second step; one side of the stop bearing is propped against the second step, the other side of the stop bearing is indirectly propped against the cup bottom of the flexible gear, and the outer ring of the stop bearing is propped against the second step.

12. A harmonic reducer device as claimed in any one of claims 1 to 8, 10 to 11, wherein: the harmonic reducer device also comprises an output shaft fixedly connected with the inner ring of the output bearing and another end cover positioned at the outer side of the output bearing, and the other end cover is connected with the inner ring of the output bearing.

13. The harmonic reducer apparatus of claim 12 wherein: 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.

14. A harmonic reducer device as claimed in any one of claims 1 to 8, 10 to 11, wherein: the output bearing is a bearing with an oil seal.

15. A harmonic reducer device as claimed in any one of claims 1 to 8, 10 to 11, wherein: the wave generator body includes a rotary arm formed on the sleeve and rollers mounted at opposite ends of the rotary arm; or the wave generator body comprises a cam formed on the sleeve and a flexible bearing connected to the cam; or the wave generator body comprises an elliptical disk formed on the sleeve and a flexible bearing connected to the elliptical disk.

16. A joint, characterized in that: the joint comprising a harmonic reducer device according to any one of claims 1-15 and a drive motor for power input to the sleeve.

17. The joint of claim 16, wherein: the joint also comprises another bearing sleeved on the sleeve and a mounting piece used for limiting the other bearing, a containing space is formed between the stator and the rotor of the motor, and the other bearing is positioned in the containing space.

18. The joint of claim 17, wherein: the mounting piece comprises a plate body and a limiting ring connected to one side of the plate body, the limiting ring and the sleeve are used for radially limiting the other bearing, a third step is formed on the outer ring surface of the sleeve, and the third step and the plate body are used for axially limiting the other bearing.

19. A mechanical arm, characterized in that: the robotic arm comprising a joint according to any one of claims 16-18.

20. A robot, characterized in that: the robot comprising the mechanical arm of claim 19.