CN212020825U

CN212020825U - Robot wrist

Info

Publication number: CN212020825U
Application number: CN202020318601.8U
Authority: CN
Inventors: 谭明杭; 徐必业; 陈明亚; 胡奔
Original assignee: Guangdong Topstar Technology Co Ltd
Current assignee: Guangdong Topstar Technology Co Ltd
Priority date: 2020-03-13
Filing date: 2020-03-13
Publication date: 2020-11-27
Anticipated expiration: 2030-03-13

Abstract

The utility model discloses a robot wrist, which comprises a wrist base body, a first transmission mechanism and a second transmission mechanism, wherein the first transmission mechanism and the second transmission mechanism are positioned in the wrist base body; the first transmission mechanism is provided with a first sealing element, and the first transmission mechanism is in sealing fit with the wrist substrate through the first sealing element; the second transmission mechanism is provided with a second sealing element, and the second transmission mechanism is in sealing fit with the wrist substrate through the second sealing element. The utility model discloses a robot wrist is provided with first sealing member because first drive mechanism is provided with, is provided with the second sealing member in the second drive mechanism for whole robot wrist has good sealing performance, can not produce phenomenons such as oil leakage.

Description

Robot wrist

Technical Field

The utility model relates to an automation equipment technical field especially relates to a robot wrist.

Background

At present, with the continuous development of industrial automation, the technology of the auxiliary robot has also been developed rapidly. In industrial production and manufacturing, the robot plays an extremely important role in transferring workpieces and materials, and the automatic production efficiency is greatly improved. In the prior art, the wrist part of the manipulator mostly adopts multi-stage transmission, the transmission efficiency is low, the occupied space is large, and the end load of the wrist is easy to be overlarge, so that the performance of the robot is reduced; on the other hand, the existing mechanical arm is poor in sealing performance and has oil leakage risk, and the existing mechanical arm is complex in design, high in cost and complex to disassemble and assemble.

Therefore, there is a need for a robot wrist with simple structure, easy assembly and disassembly, and sealing performance.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a simple structure, the dismouting of being convenient for and robot wrist that has sealing performance.

In order to achieve the purpose, the utility model provides a robot wrist, which comprises a wrist base body, a first transmission mechanism and a second transmission mechanism, wherein the first transmission mechanism and the second transmission mechanism are positioned in the wrist base body and are linked; the first transmission mechanism is provided with a first sealing element, and the first transmission mechanism is in sealing fit with the wrist substrate through the first sealing element; the second transmission mechanism is provided with a second sealing element, and the second transmission mechanism is in sealing fit with the wrist substrate through the second sealing element.

Compared with the prior art, the utility model provides a robot wrist, including the first drive mechanism and the second drive mechanism of linkage, power conveys the second drive mechanism by first drive mechanism, the utility model discloses a robot wrist is as the important joint of manipulator activity, simple structure, and power transmission is convenient. Because be provided with first sealing member in the first drive mechanism, be provided with the second sealing member in the second drive mechanism for whole robot wrist has good sealing performance, can not produce the phenomenon such as oil leakage.

Preferably, the first transmission mechanism comprises a first bevel gear, and the second transmission mechanism comprises a second bevel gear, the first bevel gear engaging with the second bevel gear. The power is transmitted to the second transmission mechanism from the first transmission mechanism through the meshing of the first bevel gear and the second bevel gear, the structure is simple, and the operation is convenient.

Preferably, the first transmission mechanism further includes a first transmission shaft for mounting the first bevel gear, the first bevel gear is mounted at one end of the first transmission shaft, and the first transmission shaft is operated to operate the first bevel gear. The first bevel gear is arranged on the first transmission shaft, the first bevel gear moves along with the movement of the first transmission shaft, and power is transmitted to the first bevel gear through the first transmission shaft and then transmitted to the second transmission mechanism through the first bevel gear.

Preferably, the first transmission mechanism further includes a first bearing and a first bearing seat, the first bearing seat is mounted on the wrist substrate, the first bearing is rotatably mounted outside the first bearing seat, the first bearing seat is provided with a first mounting hole for mounting the first transmission shaft, and one end of the first transmission shaft, which is far away from the first bevel gear, is mounted in the first mounting hole in a penetrating manner. The first bearing seat is fixed on the wrist base body, the first bearing is in transition fit with the first bearing seat, the first bearing is sleeved on the first bearing seat, the first transmission shaft is rotatably installed in the first bearing seat, and the first transmission shaft is fixed on the wrist base body through the first bearing seat.

Preferably, the first transmission mechanism further comprises a second bearing, the second bearing is located in the first bearing seat and is matched with the first transmission shaft. The second bearing is located in the first bearing seat, and the first transmission shaft is matched with the first bearing seat through the second bearing.

Preferably, the first sealing element comprises a first sealing ring and a first oil seal, the first sealing ring is mounted on the first bearing seat and matched with the wrist base body, the first oil seal is annular, an inner ring of the first oil seal is matched with the first transmission shaft, and an outer ring of the first oil seal is matched with the first bearing seat. Set up first sealing member in the first drive mechanism, first sealing member includes first sealing washer and first oil blanket, and first sealing washer makes and has good sealing performance between first drive mechanism and the wrist base member, and first oil blanket makes first transmission shaft and power input device have good sealing performance.

Preferably, a jackscrew hole used for installing a first jackscrew is formed in the first bevel gear, the first jackscrew is installed in the jackscrew hole to radially fix the first bevel gear and the first transmission shaft, a first locking piece is arranged at the end of the first bevel gear, and the first bevel gear is axially fixed on the first transmission shaft through the first locking piece. The first bevel gear is radially fixed with the first transmission shaft through a jackscrew, and the first bevel gear is axially positioned with the first transmission shaft through the cooperation of a screw and a locking gasket; the connection of the second bevel gear to the second transmission shaft is similar to the assembly of the first bevel gear to the first transmission shaft.

Preferably, the second bevel gear is connected with a second transmission shaft, the second transmission shaft is fixed on the wrist base body through a second bearing seat, and the second bevel gear is meshed with the first bevel gear, so that the power of the first transmission mechanism is output through the second transmission shaft. The second transmission shaft is matched with the second bearing seat through a bearing and is fixed on the wrist substrate through the second bearing seat; the second bevel gear is meshed with the first bevel gear, so that the power on the first transmission mechanism is output to a mechanical finger or other mechanisms through the second transmission shaft.

Preferably, the second sealing element comprises a second sealing ring and a second oil seal, and the second sealing ring is arranged on the second bearing seat and matched with the wrist base body; the second oil seal is annular, the inner ring of the second oil seal is matched with the second transmission shaft, and the outer ring of the second oil seal is matched with the second bearing seat. A second sealing element is arranged in the second transmission mechanism and comprises a second sealing ring and a second oil seal, the second sealing ring enables good sealing performance to be achieved between the second transmission mechanism and the wrist base body, and the second oil seal enables the second transmission shaft and the power input device to have good sealing performance.

Preferably, the second transmission mechanism further comprises a third bearing, and the third bearing is installed in the second bearing seat and is matched with the second transmission shaft. The second transmission shaft is matched with the second bearing seat through a third bearing, and the second transmission shaft is fixed on the wrist base body through the second bearing seat, so that the second bevel gear drives the second transmission shaft to move.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without any creative effort.

Fig. 1 is a schematic structural diagram of a robot wrist according to an embodiment of the present invention.

Figure 2 is a cross-sectional view of the robot wrist of figure 1.

FIG. 3 is a schematic diagram of the structure of the wrist substrate of FIG. 1.

Fig. 4 is a schematic view of the internal structure of the wrist of the robot of fig. 1 with the wrist substrate removed.

Fig. 5 is a schematic structural diagram of the first transmission mechanism in fig. 1.

Fig. 6 is an exploded view of fig. 5.

Fig. 7 is a schematic structural view of the second transmission mechanism in fig. 1.

Fig. 8 is an exploded view of fig. 7.

Description of reference numerals:

100. a robot wrist;

10. a first transmission mechanism; 11. a first bevel gear; 111. a first bevel gear body; 112. a first jackscrew; 113. a first locking member; 12. a first drive shaft; 13. a first bearing housing; 131. a first connection assembly; 14. a first bearing; 15. a second bearing; 151. a second connection assembly; 16. a first seal member; 161. a first seal ring; 162. a first oil seal; 17. a spacer assembly; 171. an inner spacer sleeve; 172. an outer spacer sleeve; 18. a gear assembly;

20. a second transmission mechanism; 21. a second bevel gear; 211. a second bevel gear body; 212. a second jackscrew; 213. a second locking member; 22. a second drive shaft; 23. a second bearing housing; 231. a third connection assembly; 24. a third bearing; 241. a fourth connection assembly; 25. a second seal member; 251. a second seal ring; 252. a second oil seal; 26. an external component; 261. a fifth connection assembly;

30. a wrist substrate; 31. a substrate connecting assembly; 32. a first cavity; 33. a second cavity.

Detailed Description

In order to explain technical contents and structural features of the present invention in detail, the following description is made with reference to the embodiments and the accompanying drawings.

Referring to fig. 1 and 2, the present invention provides a robot wrist 100, which includes a wrist base 30, and a first transmission mechanism 10 and a second transmission mechanism 20 located in the wrist base 30, wherein the first transmission mechanism 10 is linked with the second transmission mechanism 20. Specifically, the first transmission mechanism 10 is provided with a first sealing member 16, and the first transmission mechanism 10 is hermetically engaged with the wrist substrate 30 through the first sealing member 16. The second transmission mechanism 20 is provided with a second sealing element 25, and the second transmission mechanism 20 is in sealing fit with the wrist substrate 30 through the second sealing element 25.

After the technical scheme above the adoption, because the utility model provides a robot wrist 100, including the first drive mechanism 10 and the second drive mechanism 20 of linkage, power conveys second drive mechanism 20 by first drive mechanism 10, the utility model discloses a robot wrist 100 is as the important joint of manipulator activity, simple structure, and power conveying is convenient. And the first sealing element 16 is arranged in the first transmission mechanism 10, and the second sealing element 25 is arranged in the second transmission mechanism 20, so that the whole robot wrist 100 has good sealing performance, and oil leakage is avoided.

Referring to fig. 2 and 4 to 6, in some alternative embodiments, the first transmission mechanism 10 includes a first bevel gear 11, the second transmission mechanism 20 includes a second bevel gear 21, and the first bevel gear 11 is engaged with the second bevel gear 21. The power is transmitted from the first transmission mechanism 10 to the second transmission mechanism 20 through the meshing of the first bevel gear 11 and the second bevel gear 21, the structure is simple, and the operation is convenient. It will be appreciated that in the first transmission 10, the gear assembly 18 is externally connected with a power device, the gear assembly 18 transmits power to the first transmission shaft 12, the first transmission shaft 12 drives the first bevel gear 11, and the first bevel gear 11 is engaged with the second bevel gear 21, so that power is transmitted from the first transmission 10 to the second transmission 20.

Referring to fig. 2 and 4 to 6, in some alternative embodiments, the first transmission mechanism 10 further includes a first transmission shaft 12 for mounting the first bevel gear 11, the first bevel gear 11 is mounted at one end of the first transmission shaft 12, and the first transmission shaft 12 drives the first bevel gear 11 to move.

Referring to fig. 2 and 6, in the present embodiment, the first bevel gear 11 is mounted on the first transmission shaft 12, the first bevel gear 11 includes a first bevel gear body 111, a first screw hole for mounting the first screw 112 is formed on the first bevel gear body 111, and the first screw 112 is mounted in the first screw hole to radially fix the first bevel gear 11 and the first transmission shaft 12. In addition, the end of the first bevel gear 11 is fixed to the first transmission shaft 12 through the first locking member 113 to axially fix the first bevel gear 11 and the first transmission shaft 12, so that the first bevel gear 11 is respectively fixed to the first transmission shaft 12 in the radial direction and the axial direction, and the structure is stable and does not swing. The first locking member 113 may be a screw used in conjunction with a washer, or may be a cylindrical fastening glue instead of the screw and the washer. The first bevel gear 11 is fixed to the first transmission shaft 12 and operates in accordance with the operation of the first transmission shaft 12, and power is transmitted from the first transmission shaft 12 to the first bevel gear 11 and transmitted to the second transmission mechanism 20 as the first bevel gear 11 engages with the second bevel gear 21.

Referring to fig. 2 and 4 to 6, in some alternative embodiments, the first transmission mechanism 10 further includes a first bearing 14 and a first bearing seat 13, the first bearing seat 13 is mounted on the wrist base 30 through a first connecting component 131, the first bearing 14 is rotatably sleeved on the outer periphery of the first bearing seat 13, and the first bearing 14 is in transition fit with the first bearing seat 13. Specifically, a first mounting hole for mounting the first transmission shaft 12 is formed in the first bearing seat 13, and one end of the first transmission shaft 12, which is far away from the first bevel gear 11, penetrates through the first mounting hole. It can be understood that the first bearing seat 13 is fixed to the wrist base 30 through the first connecting component 131, the first bearing 14 is in transition fit with the first bearing seat 13, the first bearing 14 is mounted on the first bearing seat 13 in a sleeved manner, the first transmission shaft 12 is rotatably mounted in the first bearing seat 13, and the first transmission shaft 12 is fixed to the wrist base 30 through the first bearing seat 13.

Referring to fig. 2 and 4 to 6, in some alternative embodiments, the first transmission mechanism 10 further includes a second bearing 15, and the second bearing 15 is located in the first bearing seat 13 and is engaged with the first transmission shaft 12. It will be appreciated that a second bearing 15 is also provided between the first bearing block 13 and the first drive shaft 12, i.e. the second bearing 15 is located within the first bearing block 13, and the first drive shaft 12 is engaged with the first bearing block 13 via the second bearing 15. The first bearing housing 13 is provided at an end near the first bevel gear 11 with a second coupling assembly 151 for fixing the second bearing 15, and the second bearing 15 is mounted in the first bearing housing 13 by the second coupling assembly 151. In this embodiment, the number of the second bearings 15 is two, two second bearings 15 are both installed in the first bearing seat 13, the spacer assembly 17 is disposed between the two second bearings 15, the spacer assembly 17 includes an inner spacer 171 and an outer spacer 172, the inner spacer 171 is installed on the first transmission shaft 12, and the outer spacer 172 is sleeved outside the inner spacer 171. A spacer assembly 17 is arranged in the middle of the oppositely arranged bearings, so that the play and the pre-pressure between the bearings can be adjusted, and the function of protecting the bearings is achieved.

Referring to fig. 2 and 4 to 6, the first sealing element 16 includes a first sealing ring 161 and a first oil seal 162, and the first sealing ring 161 is mounted on the first bearing seat 13 and is engaged with the wrist substrate 30, so that the first bearing seat 13 and the wrist substrate 30 have good sealing effect. The first oil seal 162 is annular, an inner ring of the first oil seal 162 is matched with the first transmission shaft 12, and an outer ring of the first oil seal 162 is matched with the first bearing seat 13. It is understood that the first sealing member 16 is disposed in the first transmission mechanism 10, the first sealing member 16 includes a first sealing ring 161 and a first oil seal 162, the first sealing ring 161 provides good sealing performance between the first transmission mechanism 10 and the wrist substrate 30, and the first oil seal 162 provides good sealing performance between the first transmission shaft 12 and the power input device to prevent the penetration of lubricating oil.

Referring to fig. 2, 4, 7 and 8, in some alternative embodiments, the second bevel gear 21 is connected to a second transmission shaft 22, and the second transmission shaft 22 is fixed to the wrist base 30 through a second bearing seat 23. The second bearing seat 23 is fixed to the wrist base 30 by a third connecting component 231, and engages with the first bevel gear 11 by the second bevel gear 21, so as to output the power of the first transmission mechanism 10 from the second transmission shaft 22. It will be appreciated that the second drive shaft 22 cooperates with the second bearing block 23 via the third bearing 24, and that the second drive shaft 22 is secured to the wrist base 30 via the second bearing block 23. Since the second bevel gear 21 is engaged with the first bevel gear 11, the power of the first transmission mechanism 10 can be output to a mechanical finger or other mechanism through the second transmission shaft 22.

Referring to fig. 2 and 8, in the present embodiment, the second bevel gear 21 is mounted on the second transmission shaft 22, the second bevel gear 21 includes a second bevel gear body 211, a second screw hole for mounting the second screw 212 is formed on the second bevel gear body 211, and the second screw 212 is mounted on the screw hole to radially fix the second bevel gear 21 and the second transmission shaft 22. In addition, the end of the second bevel gear 21 is fixed to the second transmission shaft 22 through the second locking member 213 to axially fix the second bevel gear 21 and the second transmission shaft 22, so that the second bevel gear 21 is respectively fixed to the second transmission shaft 22 in the radial direction and the axial direction, and the structure is stable and does not swing. The second locking member 213 may be a screw used in combination with a washer, or a cylindrical fastening glue may be used instead of the screw and the washer. The second bevel gear 21 is fixed to the second transmission shaft 22 and operates in accordance with the operation of the second transmission shaft 22, and power is transmitted from the first transmission shaft 12 to the first bevel gear 11, and the first bevel gear 11 engages with the second bevel gear 21, so that power can be transmitted to the second transmission mechanism 20.

Referring to fig. 3, in some alternative embodiments, the wrist substrate 30 includes a substrate connecting component 31 connected to other mechanisms, a first cavity 32 for mounting the first transmission mechanism 10, and a second cavity 33 for mounting the second transmission mechanism 20, and the wrist substrate 30 is tightly and stably fitted with the first transmission mechanism 10 and the second transmission mechanism 20.

Referring to fig. 2, 4, 7 and 8, in some alternative embodiments, the second seal 25 includes a second seal ring 251 and a second oil seal 252. Specifically, the second seal ring 251 is mounted on the second bearing seat 23 to cooperate with the wrist base 30; and the second oil seal 252 is annular, the inner ring of the second oil seal 252 is matched with the second transmission shaft 22, and the outer ring of the second oil seal 252 is matched with the second bearing seat 23. It will be appreciated that a second seal 25 is provided in the second transmission mechanism 20, the second seal 25 comprises a second seal ring 251 and a second oil seal 252, the second seal ring 251 provides good sealing performance between the second transmission mechanism 20 and the wrist substrate 30, and the second oil seal 252 provides good sealing performance between the second transmission shaft 22 and the power input device.

Referring to fig. 2, 4, 7 and 8, in some alternative embodiments, the second transmission mechanism 20 further includes a third bearing 24, specifically, the third bearing 24 is installed in the second bearing seat 23 through a fourth connecting assembly 241, and the third bearing 24 is matched with the second transmission shaft 22. It will be appreciated that the second transmission shaft 22 cooperates with the second bearing housing 23 via a third bearing 24, i.e. a third bearing 24 is arranged between the second transmission shaft 22 and the wrist base 30, and the third bearing 24 is mounted in the second bearing housing 23 via a fourth connecting assembly 241. The second transmission shaft 22 is fixed to the wrist substrate 30 through a second bearing seat 23, so that the second bevel gear 21 drives the second transmission shaft 22 to move. In the present embodiment, the number of the third bearings 24 is two, and two third bearings 24 are installed in the second bearing housing 23.

Referring to fig. 7 and 8, in some alternative embodiments, the second transmission mechanism 20 further includes an external connection component 26, the external connection component 26 is mounted on the second bearing seat 23 through a fifth connection component 261, and the external connection component 26 may be connected to a mechanical finger or other mechanism.

Referring to fig. 1 and 2, in the first transmission mechanism 10, first, the first bearing 14 is in transition fit with the first bearing seat 13, and the first bearing 14 is installed outside the first bearing seat 13. Next, the first second bearing 15, the inner spacer 171, the outer spacer 172, and the second bearing 15 are sequentially installed in the first bearing housing 13. Then, the first transmission shaft 12 is matched with the components in the first bearing seat 13, and then the first bevel gear 11 is installed, the first bevel gear 11 is radially fixed with the first transmission shaft 12 through the first jackscrew 112, and the first bevel gear 11 is axially fixed with the first transmission shaft 12 through the first locking piece 113. The rotation of the first transmission shaft 12 drives the first bevel gear 11 to rotate as power input. Then, a first oil seal 162 is arranged at one end of the first transmission shaft 12 far away from the first bevel gear 11, the outer ring of the first oil seal 162 is matched with the first bearing seat 13, and the inner ring of the first oil seal 162 is matched with the first transmission shaft 12 for sealing. Finally, the first transmission mechanism 10 is fixed to the wrist base 30 by the first connecting member 131, i.e., the fixing screw, thereby completing the assembly of the power input module, i.e., the first transmission mechanism 10.

Referring to fig. 1 and 2, in the second transmission mechanism 20, first, the outer ring of the second oil seal 252 is in transition fit with the second bearing seat 23, and the second oil seal 252 is installed in the second bearing seat 23; then two third bearings 24 are installed in the second bearing support 23; the second drive shaft 22 is then mounted in two third bearings 24; and a second bevel gear 21 is arranged at the end part of the second transmission shaft 22, the second bevel gear 21 is radially fixed with the second transmission shaft 22 through a second jackscrew 212, and the second bevel gear 21 is axially fixed with the second transmission shaft 22 through a second locking piece 213. The second bevel gear 21 is engaged with the first bevel gear 11, the rotation of the first bevel gear 11 drives the second bevel gear 21 to rotate, and further drives the second transmission shaft 22 to rotate, and finally the second transmission mechanism 20 is fixed on the wrist substrate 30 through the third connecting assembly 231, so as to complete the assembly of the power output module, i.e. the second transmission mechanism 20.

Compared with the prior art, the utility model provides a robot wrist 100, including the first drive mechanism 10 and the second drive mechanism 20 of linkage, power is conveyed second drive mechanism 20 by first drive mechanism 10, the utility model discloses a robot wrist 100 is as the important joint of manipulator activity, simple structure, easy dismounting, and power conveying is convenient. And the first sealing element 16 is arranged in the first transmission mechanism 10, and the second sealing element 25 is arranged in the second transmission mechanism 20, so that the whole robot wrist 100 has good sealing performance, and oil leakage is avoided.

The above disclosure is only a preferred embodiment of the present invention, and the scope of the claims of the present invention should not be limited thereby, and all the equivalent changes made in the claims of the present invention are intended to be covered by the present invention.

Claims

1. A robot wrist is characterized by comprising a wrist base body, a first transmission mechanism and a second transmission mechanism, wherein the first transmission mechanism and the second transmission mechanism are positioned in the wrist base body and are linked; the first transmission mechanism is provided with a first sealing element, and the first transmission mechanism is in sealing fit with the wrist base body through the first sealing element; the second transmission mechanism is provided with a second sealing element, and the second transmission mechanism is in sealing fit with the wrist base body through the second sealing element.

2. A robot wrist according to claim 1, characterised in that the first transmission comprises a first bevel gear and the second transmission comprises a second bevel gear, the first bevel gear engaging the second bevel gear.

3. A robot wrist according to claim 2, characterised in that the first transmission mechanism further comprises a first transmission shaft for mounting the first bevel gear, the first bevel gear being mounted at one end of the first transmission shaft, whereby the first transmission shaft is actuated to actuate the first bevel gear.

4. A robot wrist according to claim 3, wherein the first transmission mechanism further includes a first bearing and a first bearing seat, the first bearing seat is mounted on the wrist base, the first bearing is rotatably mounted outside the first bearing seat, the first bearing seat is provided with a first mounting hole for mounting the first transmission shaft, and one end of the first transmission shaft, which is far away from the first bevel gear, is mounted in the first mounting hole in a penetrating manner.

5. A robot wrist according to claim 4, characterised in that the first transmission mechanism further comprises a second bearing located within the first bearing block and cooperating with the first transmission shaft.

6. A robot wrist according to claim 4, wherein the first seal comprises a first seal ring mounted on the first bearing seat to engage with the wrist base, and a first oil seal in the form of a ring, an inner race of the first oil seal engaging with the first drive shaft, and an outer race of the first oil seal engaging with the first bearing seat.

7. A robot wrist according to claim 3, wherein the first bevel gear is provided with a jack screw hole for mounting a first jack screw, the first jack screw is mounted in the jack screw hole to radially fix the first bevel gear and the first transmission shaft, a first locking member is provided at an end of the first bevel gear, and the first bevel gear is axially fixed to the first transmission shaft by the first locking member.

8. A robot wrist according to claim 2, characterized in that a second transmission shaft is connected to the second bevel gear, the second transmission shaft is fixed to the wrist base through a second bearing seat, and the second bevel gear is engaged with the first bevel gear to output the power of the first transmission mechanism through the second transmission shaft.

9. A robot wrist according to claim 8, wherein the second seal comprises a second seal ring and a second oil seal, the second seal ring being mounted on the second bearing block in engagement with the wrist base; the second oil seal is annular, the inner ring of the second oil seal is matched with the second transmission shaft, and the outer ring of the second oil seal is matched with the second bearing seat.

10. A robot wrist according to claim 8, characterised in that the second transmission mechanism further comprises a third bearing mounted in the second bearing housing and cooperating with the second transmission shaft.