Joint sealing structure and joint module

Abstract

The utility model discloses a joint sealing structure and a joint module. The joint sealing structure comprises a first labyrinth sealing unit and a second labyrinth sealing unit, wherein the first labyrinth sealing unit is arranged between the first end of a wave generator of the harmonic speed reducer and a motor shell, and the second labyrinth sealing unit is arranged between the second end of the wave generator and a flexible gear assembly of the harmonic speed reducer. The joint sealing structure and the joint module can improve sealing performance, solve the problem of oil leakage caused by air pressure difference inside and outside the speed reducer, and are simple and compact in structure.

Description

Technical Field

[0001] The utility model relates to the technical field of robots, in particular to a joint sealing structure and a joint module. Background Art

[0002] As the application of robots increases, collaborative robots, as automated labor that works in collaboration with humans, have entered more light industrial production. The movement of each degree of freedom of the collaborative robot is generated by the joint module at each joint, and the joint module is an integrated structure that integrates core components such as motor components, encoders, reducers and brakes. The joint module usually uses a harmonic reducer as the motion actuator, and transmits power to the output part after the harmonic reducer reduces the speed. In order to ensure the normal operation of the harmonic reducer, appropriate lubricating grease is applied inside the harmonic reducer to achieve the purpose of lubrication and heat dissipation.

[0003] In order to prevent the lubricating grease in the harmonic reducer from being thrown out and causing the amount of grease in the harmonic reducer to decrease, in the previous technology, an oil seal is set at both ends of the camshaft of the harmonic reducer to prevent the grease inside the harmonic reducer from flowing out to the frameless motor, brake and driver, thereby affecting the appearance and stability of the whole machine. The seals at both ends of the camshaft use O-type oil seals as dynamic seals, which are very easy to damage. The oil seal is large in size, which makes the overall axial length of the joint longer, and has special requirements for the matching workpiece material and processing accuracy, which cannot meet the needs of the refined design of the collaborative robot joint. With the use of oil seals, the reducer is prone to internal temperature rise during high-load and high-speed operation, resulting in the internal cavity air pressure being higher than the external air pressure, and the oil seal fails, resulting in less grease leakage. When using oil seals, standard oil seals cannot meet the tolerance requirements, and special customization of the oil seal inner diameter tolerance is required, which is costly. In addition, the oil seals always have friction resistance on the input and output shafts, especially the motor input shaft, sacrificing part of the motor's output torque and affecting the starting torque of the reducer. At the same time, during continuous operation, the friction between the oil seal and the input shaft and output shaft generates heat, which will also affect the stability and life of the joint module, and the joints need frequent maintenance and replacement of oil seals. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a joint sealing structure and a joint module.

[0005] In order to solve the above technical problems, a technical solution adopted by the utility model is: providing a joint sealing structure, including a first labyrinth sealing unit arranged between the first end of the wave generator of the harmonic reducer and the motor housing, and a second labyrinth sealing unit arranged between the second end of the wave generator and the flexible wheel assembly of the harmonic reducer.

[0006] Furthermore, the first labyrinth seal unit includes a first sealing ring groove arranged at a position on the first end of the motor housing facing the wave generator, the first sealing ring groove is recessed from the first end surface of the motor housing in a direction away from the wave generator, and the opening of the first sealing ring groove faces the wave generator; the first labyrinth seal unit also includes a first sealing convex ring arranged at a position on the first end of the wave generator facing the first sealing ring groove, and the first sealing convex ring is inserted into the first sealing ring groove along the axial direction of the wave generator.

[0007] Furthermore, a first convex ring is provided at a position of the first end of the motor housing directly opposite to the wave generator, and the first convex ring is formed by protruding toward the wave generator. A first through hole is formed in the first convex ring and penetrates along its axial direction to communicate with the inner cavity of the motor housing, and the first sealing ring groove is provided on the first end face of the first convex ring facing the wave generator.

[0008] Furthermore, the first sealing convex ring is arranged on the first end surface of the camshaft of the wave generator, and the first end surface of the camshaft is provided with a second convex ring extending into the first through hole, and the second convex ring is located inside the first sealing convex ring and is coaxially arranged therewith.

[0009] Furthermore, a flexible bearing is provided on the outer periphery of the camshaft, and the first sealing protrusion ring is defined as a bearing retaining ring provided on the first end surface of the camshaft.

[0010] Furthermore, the second labyrinth sealing unit includes a second sealing ring groove arranged at the second end of the camshaft of the wave generator, and the second sealing ring groove is recessed from the second end surface of the wave generator toward the first end; the second labyrinth sealing unit also includes a second sealing convex ring arranged at a position on the flexible wheel assembly facing the second sealing ring groove, and the second sealing convex ring is inserted into the second sealing ring groove along the axial direction of the wave generator.

[0011] Furthermore, the flexible wheel assembly includes a flexible wheel, a flexible wheel oil stop cover is arranged inside the flexible wheel, and the flexible wheel oil stop cover is connected to the end of the flexible wheel away from the wave generator through the flexible wheel pressure plate; the flexible wheel oil stop cover is provided with a second through hole on a side surface of the flexible wheel oil stop cover facing the wave generator, and the second sealing convex ring surrounds the outer periphery of the second through hole and is coaxially arranged with the second through hole.

[0012] Furthermore, the periphery of the second through hole protrudes toward the camshaft to form a fourth convex ring, and the fourth convex ring is located inside the second sealing convex ring and is coaxially arranged therewith; the fourth convex ring is assembled in the inner groove wall of the second sealing ring groove, and the second sealing convex ring is assembled in the first sealing ring groove, and a fourth sealing ring groove is formed between the fourth convex ring and the second sealing convex ring, and the fourth sealing ring groove is used for the inner groove wall of the second sealing ring groove to be inserted therein.

[0013] Furthermore, the harmonic reducer is fixed to the first end of the motor housing through a reducer flange, and a first sealing gasket is arranged between the first end of the motor housing and the reducer flange; a second sealing gasket is arranged between the reducer flange and the steel wheel of the harmonic reducer; a third sealing gasket is arranged between the outer ring of the cross roller bearing of the harmonic reducer and a torque sensor flange; a fourth sealing gasket is arranged between the torque sensor flange and the torque sensor; a fifth sealing gasket is arranged between the flexible wheel pressure plate of the flexible wheel assembly and the end of the flexible wheel away from the wave generator; a sixth sealing gasket is arranged between the flexible wheel oil stop cover of the flexible wheel assembly and the flexible wheel pressure plate; and an oil seal is arranged between the outer ring and the inner ring of the cross roller bearing.

[0014] In order to solve the above technical problems, another technical solution adopted by the present invention is: providing a joint module, including the joint sealing structure.

[0015] The joint sealing structure and joint module of the utility model realize dynamic sealing at both ends of the wave generator through labyrinth sealing units. The labyrinth sealing structure with concave and convex matching can effectively reduce the length of the joint module, solve the problems of increased overall length of the joint module, complex installation, and oil seal failure caused by high internal and external air pressure due to temperature increase caused by dynamic sealing through oil seals in the prior art, increase the grease sealing effect, and solve the problem of increased friction resistance between the input and output shafts due to oil seal tolerance in the prior art, thereby affecting the output torque. The labyrinth sealing structure of the present application can improve the output efficiency of the motor and the transmission efficiency of the reducer, reduce the friction resistance of the reducer and the motor, replace the traditional oil seal design, change the supporting assembly relationship between the camshaft of the wave generator and the motor housing and the flexible wheel, and make full use of the internal space of the reducer to design a labyrinth structure. Improve the sealing of the joint module, overcome the oil leakage problem caused by the pressure difference between the inside and outside of the reducer, and have a simple and compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 It is an assembly schematic diagram of an implementation scheme of a joint sealing structure of the utility model.

[0018] Figure 2 yes Figure 1 Section view along the AA direction.

[0019] Figure 3 yes Figure 1 Cross-sectional view of the motor housing in the AA direction.

[0020] Figure 4 yes Figure 2 Enlarged view of part A in the figure.

[0021] Figure 5 yes Figure 2 Enlarged view of part B in the middle.

[0022] The accompanying drawings in the specification are numeraled as follows:

[0023] Motor housing 100; inner cavity 110; first through hole 120; first convex ring 130; third convex ring 140; first O-ring 141; harmonic reducer 200; steel wheel 210; cross roller bearing 220; oil seal 221; inner ring 222; outer ring 223; third O-ring 223a; wave generator 230; camshaft 231; flexible bearing 232; stop block 233; bearing retaining ring 234; second convex ring 235 ; Flexspline assembly 240; Flexspline 241; Flexspline pressure plate 242; fifth O-ring 242a; outer ring wall 2421; sixth O-ring 2421a; Flexspline oil stop cover 243; cover plate 2431; outer cover wall 2432; second through hole 2433; fourth convex ring 2434; reducer flange 250; second O-ring 251; torque sensor flange 260; fourth O-ring 261; torque sensor 270;

[0024] First sealing ring groove 310; inner groove wall 311; second sealing ring groove 320; second sealing convex ring 330; fourth sealing ring groove 340; DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] The present application discloses a joint module and a joint sealing structure. The joint module includes a motor housing 100, a motor assembly (not shown) arranged in the motor housing 100, a driver, a brake, an encoder, a harmonic reducer 200, etc.

[0029] See also Figure 1 , Figure 2 and Figure 3 , showing the assembly state of the motor housing 100, the harmonic reducer 200 and the joint sealing structure of the joint module. For the convenience of description, the end of the motor housing 100 close to the harmonic reducer 200 is called the first end of the motor housing 100, and the end away from the harmonic reducer 200 is called the second end of the motor housing 100; the end of the harmonic reducer 200 close to the motor housing 100 is called the first end of the harmonic reducer 200 and its parts (such as the steel wheel 210, the cross roller bearing 220, the wave generator 230, the flexible wheel assembly 240, the reducer flange 250, the torque sensor flange 260, the torque sensor 270, etc.), and the end away from the motor housing 100 is called the second end of the harmonic reducer 200 and its parts. The harmonic reducer 200 is coaxially arranged at the first end of the motor housing 100 through a reducer flange 250 , and the first end of the harmonic reducer 200 is opposite to the first end of the motor housing 100 , and the second end of the harmonic reducer 200 is opposite to the second end of the motor housing 100 .

[0030] The motor housing 100 is provided with an inner cavity 110 for installing the motor assembly. The first end of the motor housing 100 protrudes toward the harmonic reducer 200 to form a first boss. The first boss is coaxially arranged with the motor housing 100, and a first through hole 120 is provided on the first boss along its axial direction. The first through hole 120 makes the first boss become a first convex ring 130, and the first convex ring 130 is arranged toward the wave generator 230 of the harmonic reducer 200. When the motor assembly is installed in the inner cavity 110, the power shaft of the motor assembly passes through the first through hole 120 and is connected to the first end of the harmonic reducer 200.

[0031] In order to facilitate the assembly of the reducer flange 250, the harmonic reducer 200 is installed on the first end of the motor housing 100 through the reducer flange 250. A third convex ring 140 is also provided on the first end face of the motor housing 100. The second end face of the third convex ring 140 is integrally connected with the first end face of the motor housing 100. The first end face of the third convex ring 140 faces the harmonic reducer 200. The first end face of the third convex ring 140 is further away from the harmonic reducer 200, and the first end face of the first convex ring 130 is closer to the harmonic reducer 200. A first sealing gasket is provided between the first end of the motor housing 100 and the reducer flange 250. Specifically, a first sealing groove (ring groove) is provided on the outer peripheral surface of the third convex ring 140, and the first sealing gasket is embedded in the first sealing groove. The first sealing gasket is a first O-ring 141 adapted to the first sealing groove. The first O-ring 141 is sealingly matched with the outer peripheral surface of the third convex ring 140 and the inner peripheral surface of the reducer flange 250, thereby realizing static sealing between the reducer flange 250 and the third convex ring 140.

[0032] The harmonic reducer 200 can be any harmonic reducer on the market. In this embodiment, the harmonic reducer 200 includes a steel wheel 210, a cross roller bearing 220, a wave generator 230 and a flexible wheel assembly 240. A torque sensor flange 260 is installed at the second end of the harmonic reducer 200, and a torque sensor 270 is installed at the second end of the torque sensor flange 260.

[0033] The first end of the steel wheel 210 is connected to the second end of the reducer flange 250 so as to be installed on the first end of the motor housing 100 through the reducer flange 250. A second sealing groove (ring groove) is provided on the second end surface of the reducer flange 250 at a position facing the steel wheel 210, and a second sealing gasket is embedded in the second sealing groove. The second sealing gasket is a second O-type sealing ring 251 matched with the second sealing groove. The second O-type sealing ring 251 is sealed and matched between the reducer flange 250 and the steel wheel 210, thereby realizing static sealing between the reducer flange 250 and the steel wheel 210.

[0034] The second end of the steel wheel 210 is connected to the first end of the inner ring 222 of the cross roller bearing 220. An oil seal 221 is provided between the inner ring 222 and the outer ring of the cross roller bearing 220 to achieve dynamic sealing, and the oil seal 221 is close to the direction of the motor housing 100. The second end of the outer ring 223 of the cross roller bearing 220 is connected to the first end of the torque sensor flange 260. A third sealing groove is provided at the second end of the outer ring 223 of the cross roller bearing 220. A third sealing gasket is embedded in the third sealing groove. The third sealing gasket is a third O-ring 223a adapted to the third sealing groove. The third O-ring 223a is sealed and matched between the outer ring 223 of the cross roller bearing 220 and the torque sensor flange 260, thereby achieving static sealing between the outer ring 223 of the cross roller bearing 220 and the torque sensor flange 260. The second end of the torque sensor flange 260 is connected to the outer ring of the torque sensor 270, and a fourth sealing groove (annular groove) is provided at a position of the second end face of the torque sensor flange 260 close to the inner ring of the torque sensor 270, and a fourth sealing gasket is embedded in the fourth sealing groove. The fourth sealing gasket is a fourth O-ring 261 adapted to the fourth sealing groove, and the fourth O-ring 261 is sealed and fitted between the torque sensor flange 260 and the torque sensor 270, thereby realizing static sealing between the torque sensor flange 260 and the torque sensor 270.

[0035] The flexible wheel assembly 240 is arranged on the inner periphery of the cross roller bearing 220, and the flexible wheel assembly 240 includes a flexible wheel 241, a flexible wheel pressure plate 242 and a flexible wheel oil stop cover 243. The first end (open end) of the flexible wheel 241 faces the motor housing 100, and the second end (small end) of the flexible wheel 241 is connected to the inner ring of the torque sensor 270. The flexible wheel pressure plate 242 is arranged in the flexible wheel 241 and pressed against the second end of the flexible wheel 241. The flexible wheel pressure plate 242 is connected to the second end of the flexible wheel 241 and the inner ring of the torque sensor 270 by bolts. A fifth sealing groove (annular groove) is provided on the second end face of the flexible wheel pressure plate 242, in which a fifth sealing gasket is embedded. The fifth sealing gasket is a fifth O-ring 242a matched with the fifth sealing groove. The fifth O-ring 242a is sealingly fitted between the flexible wheel pressure plate 242 and the flexible wheel 241 to achieve a static seal between the flexible wheel pressure plate 242 and the flexible wheel 241, thereby used to seal dust entering the flexible wheel 241 from the inner ring of the torque sensor 270 and prevent grease in the flexible wheel 241 from leaking out.

[0036] See also Figure 4 and Figure 5 The outer peripheral edge of the flexible impeller pressure plate 242 extends toward the motor housing 100 to form an outer annular wall 2421, and the first end of the outer annular wall 2421 is covered by the flexible impeller oil stop cover 243. The flexible impeller oil stop cover 243 includes a cover plate 2431 and an outer cover wall 2432 extending from the outer peripheral edge of the cover plate 2431 toward the flexible impeller pressure plate 242, and the outer cover wall 2432 covers the outer periphery of the outer annular wall 2421. The cover plate 2431 is connected to the first end of the outer annular wall 2421 to cover the first end of the flexible impeller pressure plate 242, so that the flexible impeller oil stop cover 243 is connected to the second end of the flexible impeller 241 through the flexible impeller pressure plate 242. A sixth sealing groove (ring groove) is provided on the outer peripheral surface of the outer ring wall 2421, and a sixth sealing gasket is embedded in the sixth sealing groove. The sixth sealing gasket is a sixth O-ring 2421a adapted to the sixth sealing groove, and the sixth O-ring 2421a is sealed and matched between the flexible impeller pressure plate 242 and the flexible impeller oil stop cover 243, thereby realizing a static seal between the flexible impeller pressure plate 242 and the flexible impeller oil stop cover 243. The flexible impeller oil stop cover 243 is provided with a through second through hole 2433 on one side facing the wave generator 230, and a fourth convex ring 2434 is formed on the periphery of the second through hole 2433 protruding toward the direction of the wave generator 230, and the fourth convex ring 2434 surrounds the outer periphery of the second through hole 2433 and is coaxially arranged with the second through hole 2433.

[0037] The wave generator 230 is arranged at a position near the first end of the inner circumference of the flexible wheel 241. The wave generator 230 includes a camshaft 231 with an annular structure. A flexible bearing 232 is arranged on the outer circumference of the camshaft 231. The outer ring of the flexible bearing 232 is tightly abutted or connected to the inner circumferential wall of the first end of the flexible wheel 241. A stop block 233 for stopping the second end of the flexible bearing 232 is arranged at a position on the camshaft 231 corresponding to the second end of the flexible bearing 232. The stop block 233 is used to prevent the flexible bearing 232 from shifting toward the second end. A bearing retaining ring 234 is arranged at the first end of the camshaft 231 for stopping the first end of the flexible bearing 232. The bearing retaining ring 234 is used to prevent the flexible bearing 232 from shifting toward the first end. The first end of the camshaft 231 is also provided with a second convex ring 235 extending into the first through hole 120 of the motor housing 100. The second convex ring 235 is located on the inner periphery of the bearing retaining ring 234 and is coaxially arranged therewith. The second convex ring 235 and the bearing retaining ring 234 both protrude from the first end face of the camshaft 231 in the direction of the motor housing 100, so that the second convex ring 235 and the bearing retaining ring 234 form a third sealing ring groove 350 with an opening facing the direction of the motor housing 100. The third sealing ring groove 350 and the first sealing ring groove 310 described below are both used to collect grease flowing out of the reducer inner cavity and return the grease to the reducer inner cavity. Since there is air circulation here, the internal temperature of the reducer rises when it works for a long time, and the internal and external pressure difference is stabilized to prevent grease from overflowing. At the same time, there is a certain heat dissipation effect. The labyrinth design is adopted to make full use of the internal space of the reducer and effectively shorten the length of the joint.

[0038] The joint sealing structure includes a first labyrinth sealing unit disposed between a first end of a wave generator 230 of the harmonic reducer 200 and the motor housing 100 , and a second labyrinth sealing unit disposed between a second end of the wave generator 230 and a flexible wheel assembly 240 of the harmonic reducer 200 .

[0039] Please continue to see Figure 3 and Figure 5The first labyrinth seal unit includes a first sealing ring groove 310 disposed at a position on the first end of the motor housing 100 facing the wave generator 230, the first sealing ring groove 310 is recessed from the first end face of the motor housing 100 in a direction away from the wave generator 230, and the opening of the first sealing ring groove 310 faces the wave generator 230. Specifically, the first sealing ring groove 310 is disposed at the first end face of the first convex ring 130, and is recessed from the first end face of the first convex ring 130 in a direction toward the second end of the motor housing 100. The inner groove wall 311 of the first sealing ring groove 310 protrudes from the outer peripheral edge of the first through hole 120 in the direction of the wave generator 230. The first labyrinth seal unit also includes a first sealing convex ring (i.e., a bearing retaining ring 234) disposed at a position on the first end of the wave generator 230 facing the first sealing ring groove 310, and the first sealing convex ring is inserted into the first sealing ring groove 310 along the axial direction of the wave generator 230. In the embodiment shown, the bearing retaining ring 234 at the first end of the camshaft 231 is arranged opposite to the first sealing ring groove 310, so the bearing retaining ring 234 is regarded as the first sealing convex ring, so that both the stop effect on the flexible bearing 232 and the labyrinth sealing effect are achieved, which reduces the structural complexity and saves the manufacturing cost. The first sealing convex ring is coaxially arranged on the outer periphery of the second convex ring 235. After the first labyrinth sealing unit is assembled, the second convex ring 235 at the first end of the camshaft 231 extends into the inner groove wall 311 of the first sealing ring groove 310, and the inner groove wall 311 of the first sealing ring groove 310 extends between the second convex ring 235 and the first sealing convex ring (bearing retaining ring 234), and the first sealing convex ring (bearing retaining ring 234) extends into the first sealing ring groove 310, thereby forming a labyrinth sealing structure.

[0040] The second labyrinth seal unit includes a second sealing ring groove 320 disposed at the second end of the cam shaft 231 of the wave generator 230, and the second sealing ring groove 320 is recessed from the second end surface of the cam shaft 231 toward the first end. The second labyrinth seal unit also includes a second sealing convex ring 330 disposed at a position on the flexible wheel assembly 240 facing the second sealing ring groove 320, and the second sealing convex ring 330 is inserted into the second sealing ring groove 320 along the axial direction of the wave generator 230. Specifically, the second sealing convex ring 330 is arranged on the cover plate 2431 of the flexible wheel oil stop cover 243 at a position directly facing the second sealing ring groove 320. The second sealing convex ring 330 is arranged around the outside of the fourth convex ring 2434 and is arranged coaxially therewith, so that the second sealing convex ring 330 and the fourth convex ring 2434 together form a fourth sealing ring groove 340 with an opening facing the direction of the motor housing 100, and the fourth sealing ring groove 340 is used for the inner groove wall of the second sealing ring groove 320 to be inserted therein. The fourth sealing ring groove 340 and the second sealing ring groove 320 are both used to collect grease flowing out of the inner cavity of the reducer, and at the same time, the grease is returned to the inner cavity of the reducer. Since there is air circulation here, the internal temperature of the reducer rises when it works for a long time, and the internal and external pressure difference is stabilized to prevent grease from overflowing. At the same time, there is a certain heat dissipation effect. The labyrinth design is adopted to make full use of the internal space of the reducer and effectively shorten the length of the joint. After the second labyrinth sealing unit is assembled, the fourth convex ring 2434 is assembled in the inner groove wall of the second sealing ring groove 320, the inner groove wall of the second sealing ring groove 320 extends into the fourth sealing ring groove 340 (i.e., between the second sealing convex ring 330 and the fourth convex ring 2434), and the second sealing convex ring 330 is assembled in the first sealing ring groove 310, thereby forming a labyrinth sealing structure.

[0041] The utility model discloses a joint sealing structure and a joint module, which realizes dynamic sealing at both ends of the wave generator through a labyrinth sealing unit. The labyrinth sealing structure with concave and convex matching can effectively reduce the length of the joint module, solve the problems of increased overall length of the joint module, complex installation, and oil seal failure caused by the large internal and external air pressure caused by the temperature increase caused by the dynamic sealing through the oil seal in the previous technology, increase the grease sealing effect, and solve the problem of increased friction resistance between the input and output shafts due to the oil seal tolerance in the previous technology, thereby affecting the output torque. The labyrinth sealing structure of the present application can improve the output efficiency of the motor and the transmission efficiency of the reducer, reduce the friction resistance of the reducer and the motor, replace the traditional oil seal design, change the supporting assembly relationship between the camshaft of the wave generator and the motor housing and the flexible wheel, and make full use of the internal space of the reducer to design a labyrinth structure. Improve the sealing performance of the joint module, overcome the oil leakage problem caused by the internal and external air pressure difference of the reducer, and have a simple and compact structure and low manufacturing cost.

[0042] The above embodiments only express the preferred implementation of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A joint sealing structure, characterized in that: The invention comprises a first labyrinth seal unit arranged between a first end of a wave generator of a harmonic reducer and a motor housing, and a second labyrinth seal unit arranged between a second end of the wave generator and a flexible wheel assembly of the harmonic reducer.

2. The joint sealing structure according to claim 1, characterized in that: The first labyrinth seal unit includes a first sealing ring groove arranged at a position on the first end of the motor housing facing the wave generator, the first sealing ring groove is recessed from the first end surface of the motor housing in a direction away from the wave generator, and the opening of the first sealing ring groove faces the wave generator; the first labyrinth seal unit also includes a first sealing convex ring arranged at a position on the first end of the wave generator facing the first sealing ring groove, and the first sealing convex ring is inserted into the first sealing ring groove along the axial direction of the wave generator.

3. The joint sealing structure according to claim 2, characterized in that: A first convex ring is provided at a position of the first end of the motor housing directly opposite to the wave generator. The first convex ring is formed by protruding toward the wave generator. A first through hole is formed in the first convex ring and penetrates along its axial direction to communicate with the inner cavity of the motor housing. The first sealing ring groove is provided on the first end face of the first convex ring facing the wave generator.

4. The joint sealing structure according to claim 3, characterized in that: The first sealing convex ring is arranged on the first end surface of the camshaft of the wave generator, and the first end surface of the camshaft is provided with a second convex ring extending into the first through hole, and the second convex ring is located inside the first sealing convex ring and is coaxially arranged therewith.

5. The joint sealing structure according to claim 4, characterized in that: A flexible bearing is disposed on the outer periphery of the camshaft, and the first sealing protrusion ring is defined as a bearing retaining ring disposed on the first end surface of the camshaft.

6. The joint sealing structure according to claim 2, characterized in that: The second labyrinth sealing unit includes a second sealing ring groove arranged at the second end of the camshaft of the wave generator, and the second sealing ring groove is recessed from the second end surface of the wave generator toward the first end; the second labyrinth sealing unit also includes a second sealing convex ring arranged at a position on the flexible wheel assembly facing the second sealing ring groove, and the second sealing convex ring is inserted into the second sealing ring groove along the axial direction of the wave generator.

7. The joint sealing structure according to claim 6, characterized in that: The flexible wheel assembly includes a flexible wheel, a flexible wheel oil stop cover is arranged inside the flexible wheel, and the flexible wheel oil stop cover is connected to the end of the flexible wheel away from the wave generator through the flexible wheel pressure plate; the flexible wheel oil stop cover is provided with a second through hole on a side surface facing the wave generator, and the second sealing convex ring surrounds the outer periphery of the second through hole and is coaxially arranged with the second through hole.

8. The joint sealing structure according to claim 7, characterized in that: The periphery of the second through hole protrudes toward the camshaft to form a fourth convex ring, and the fourth convex ring is located inside the second sealing convex ring and is coaxially arranged therewith; the fourth convex ring is assembled in the inner groove wall of the second sealing ring groove, and the second sealing convex ring is assembled in the first sealing ring groove, and a fourth sealing ring groove is formed between the fourth convex ring and the second sealing convex ring, and the fourth sealing ring groove is used for the inner groove wall of the second sealing ring groove to be inserted therein.

9. The joint sealing structure according to any one of claims 1 to 8, characterized in that: The harmonic reducer is fixed to the first end of the motor housing through a reducer flange, and a first sealing gasket is arranged between the first end of the motor housing and the reducer flange; a second sealing gasket is arranged between the reducer flange and the steel wheel of the harmonic reducer; a third sealing gasket is arranged between the outer ring of the cross roller bearing of the harmonic reducer and a torque sensor flange; a fourth sealing gasket is arranged between the torque sensor flange and the torque sensor; a fifth sealing gasket is arranged between the flexible wheel pressure plate of the flexible wheel assembly and the end of the flexible wheel away from the wave generator; a sixth sealing gasket is arranged between the flexible wheel oil stop cover of the flexible wheel assembly and the flexible wheel pressure plate; and an oil seal is arranged between the outer ring and the inner ring of the cross roller bearing.

10. A joint module, characterized in that: Comprising the joint sealing structure according to any one of claims 1 to 9.

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