Industrial Robot And Method For Moving A Robot Arm In A Clean Room

Abstract

An industrial robot includes a robot control configured to execute a robot program and a robot arm having a plurality of links connected by joints. The joints are configured to automatically adjust the links relative to one another according to the robot program, wherein at least one of the joints is configured as a rotary joint that connects a first link of the plurality of links to an adjacent second link for rotation relative to one another. The first link comprises a shaft sealing ring that has a sealing lip formed from a PTFE material, and the second link has a shaft portion with a running surface formed from a PTFE material, on which the shaft sealing ring bears with its sealing lip in a sealing manner. A method for moving the robot arm in a clean room is also disclosed.

Claims

1-10. (canceled)

11. An industrial robot comprising: a robot control configured to execute a robot program; a robot arm with a plurality of links connected by joints, the joints configured for automatic mutual adjustment of the links according to the robot program; at least one of the joints configured as a rotary joint connecting a first link of the plurality of links to an adjacent second link for relative rotation of the first and second links; the first link comprising a shaft seal which includes a sealing lip made from a PTFE material; and the second link comprising a shaft section which includes a tread made from a PTFE material; the sealing lip of the shaft seal contacting the tread in a sealing fashion.

12. The industrial robot of claim 11, wherein the second link comprises a shaft section including a tread made from a POM-PTFE copolymer material.

13. The industrial robot of claim 11, wherein the tread is formed by an external jacket wall of a tread ring which is fastened on the shaft section of the second link.

14. The industrial robot of claim 13, wherein the tread ring is fastened on the shaft section of the second link by bonding.

15. The industrial robot of claim 14, wherein the tread ring is fastened on the shaft section by thermal bonding.

16. The industrial robot of claim 13, wherein the tread ring is fastened on the shaft section of the second link by compression.

17. The industrial robot of claim 16, wherein the compression comprises shrink-wrapping the tread ring on the shaft section.

18. The industrial robot of claim 11, wherein the tread is produced by coating the shaft section of the second link with PTFE-material, thereby forming a PTFE-layer on the shaft section.

19. The industrial robot of claim 18, wherein the tread is produced by powder coating, the shaft section of the second link.

20. The industrial robot of claim 19, wherein the powder coating comprises a PTFE-powder or a PTFE-powder mixture.

21. The industrial robot of claim 11, wherein the sealing lip of the shaft seal and the tread are made from the same PTFE-material.

22. The industrial robot of claim 11, wherein the sealing lip of the shaft seal does not include a tension spring.

23. The industrial robot of claim 11, wherein the shaft seal is a membrane shaft seal.

24. A method for moving a robot arm of an industrial robot arranged in a cleanroom, the method comprising: obtaining a robot, the robot including: a robot control configured to execute a robot program, a robot arm with a plurality of links connected by joints, the joints configured for automatic mutual adjustment of the links according to the robot program, at least one of the joints configured as a rotary joint connecting a first link of the plurality of links to an adjacent second link for relative rotation of the first and second links, the first link comprising a shaft seal which includes a sealing lip made from a PTFE material, and the second link comprising a shaft section which includes a tread made from a PTFE material, the sealing lip of the shaft seal contacting the tread in a sealing fashion; and actuating with the robot control the automatic movement of at least one rotary joint of the robot arm at a maximum angular velocity, whereby the sealing lip of the shaft seal moves with a relative velocity in reference to the tread which is less than 1 meter per second.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various exemplary embodiments of the invention are shown in the attached schematic illustrations as examples. Concrete features of these exemplary embodiments can represent general characteristics of the invention regardless of in what concrete context they are mentioned, perhaps even individually or in combinations when analyzed.

[0032] FIG. 1 is a perspective view of an industrial robot comprising a robot arm and a robot control,

[0033] FIG. 2 is a cross-sectional detail through an exemplary rotary joint of the robot arm according to FIG. 1, which comprises an inventive shaft seal with a sealing lip made from a PTFE-material and a tread ring separated from the shaft section made from a POM-PTFE copolymer material, and

[0034] FIG. 3 is a cross-sectional detail through an exemplary rotary joint of the robot arm according to FIG. 1, which comprises an inventive shaft seal with a sealing lip made from a PTFE-material and a tread in the form of a coating comprising PTFE-material.

DETAILED DESCRIPTION

[0035] FIG. 1 shows an industrial robot 1, which comprises a robot arm 2 and a robot control 10. In the case of the present exemplary embodiment, the robot arms 2 comprises several links G1 to G7, arranged behind each other and connected via joints L1 to L6.

[0036] The robot control 10 of the industrial robot 1 is configured and/or implemented to perform a robot program, by which the joints L1 to L6 of the robot arm 2 according to the robot program can be adjusted and/or moved rotationally in an automated fashion or in a manual operation. For this purpose the robot control 10 is connected to the controllable electric drives M1 to M6, which are embodied to adjust the joints L1 to L6 of the industrial robot 1.

[0037] In case of the present exemplary embodiment the links G1 to G7 represent a frame 3 and a carousel 4 supported rotationally about an axis A1 extending vertically in reference to the frame 3. Additional links of the robot arm 2 are a link arm 5, a boom arm 6, and a robot hand 7, preferably comprising several axes, with a fastening device configured as a flange 8 for fastening a tool 11. The link arm 5 is pivotally supported at the lower end, i.e. at the joint L2 of the link arm 5, which can also be called a pivot bearing head, on the carousel 4 about a preferably horizontal rotary axis A2.

[0038] At the upper end of the link arm 5, at the first joint L3 of the link arm 5, another also preferably horizontal axis A3 of the boom arm 6 is supported pivotally. It carries at the end the robot hand 7 with its preferably three axes of rotation A4, A5, and A6. The joints L1 to L6 can generally be driven by respectively one of the electric drives M1 to M6, controlled by programs of the robot control 10. In general, here a transmission 12 may be provided between each of the links G1 to G7 and the respectively corresponding electric drive M1 to M6.

[0039] FIG. 1 shows here an industrial robot 1 comprising a robot control 10, which is configured to execute a robot program, as well as comprising a robot arm 2 with several links G1-G7, which are connected via joints L1-L6, configured for an automatic mutual adjustment of the links G1-G7 according to the robot program, with at least one of the joints being configured as a rotary joint L1-L6, which connects a first link 14 of several links G1-G7 to an adjacent second link 15 of the plurality of links G1-G7 for rotating them in reference to each other.

[0040] In FIG. 2 a rotary joint of the robot arm 2 is shown according to FIG. 1, which at a first link 14 of the robot arm 2 comprises an inventive shaft seal 12 with a sealing lip 13 made from a PTFE-material and at a shaft section 16 a second link 15 comprises a separate tread ring 17a made from a POM-PTFE copolymer material.

[0041] The first link 14 comprises therefore a shaft seal 12, which comprises a sealing lip 13 made from a PTFE-material, with the second link 15 comprising a shaft section 16, which comprises a tread 17 made from a PTFE-material at which the shaft seal 12 contacts with a sealing lip 13 in a sealing fashion.

[0042] The first link 14 is formed by a first housing part of the robot arm 2. This first housing part comprises a seat 19 for the shaft seal 12. The shaft seal 12 can in this way be pushed onto the seat 19 and for example fixed axially and radially between an O-ring 20 and a circlip 21. The tread ring 17a is fastened on a stop 22 of the shaft section 16. The shaft section 16 is connected fixed to the second link 15. The second link 15 is here formed by a second housing part of the robot arm 2.

[0043] In case of the present exemplary embodiment of FIG. 2 the tread ring 17a and thus also the tread 17 are made from a POM-PTFE copolymer material.

[0044] The tread 17 is here formed by an external jacket wall of the tread ring 17a. The tread ring 17a is fastened on the shaft section 16 of the second link 15.

[0045] The tread ring 17a can for example be fastened by bonding, particularly thermal bonding or press-fitting, particularly shrink-wrapping, on the shaft section 16.

[0046] In case of the present exemplary embodiment of FIG. 2 the sealing lip 13 of the shaft seal 12 is a sealing lip 13 without a tension spring, particularly a membrane shaft seal.

[0047] In case of the present exemplary embodiment of FIG. 2 the sealing lip 13 is configured as a single sealing lip. In case of the present exemplary embodiment of FIG. 2 the sealing lip 13 may however also be configured like the embodiment described hereinafter according to FIG. 3 as a double gasket.

[0048] In the embodiment shown in FIG. 2, in which the first link 14 of the robot arm 2 comprises the shaft seal 12 with a sealing lip 13 made from a PTFE-material and the second link 15 at the shaft section 16 the separate tread ring 17a made from a POM-PTFE copolymer material, the industrial robot 1 can be controlled via its robot control 10 for moving robot arms 2 arranged in a cleanroom 18 (FIG. 1) such that an automatic movement of at least one rotary joint occurs maximally at an angular velocity at which the sealing lip 13 of the shaft seal 12 moves with a relative velocity in reference to the tread 17, which is slower than 1 meter per second (1 m/s).

[0049] FIG. 3 shows a rotary joint of the robot arm according to FIG. 1, which comprises an inventive shaft seal 12 with a sealing lip 13 made from a PTFE-material and a tread 17 in the form of a coating 17b made from PTFE-material.

[0050] In this alternative embodiment as well the first link 14 comprises a shaft seal 12, which comprises a sealing lip 13 made from a PTFE-material, with the second link 15 comprising a shaft section 16, which shows a tread 17 made from a PTFE-material, which is configured as a coating, i.e. PTFE-layer 17b, at which the shaft seal 12 contacts with its sealing lip 13 in a sealing fashion.

[0051] The first link 14 is also formed in this embodiment by a first housing part of the robot arm 2. This first housing part comprises a seat 19 for the shaft seal 12. The shaft seal 12 can be pushed onto the seat 19 such, and for example be fixed between an O-ring 20 and a circlip 21 axially and radially by a clamping ring 23, which is screwed at the face via screws 24 to the first link. The coating, i.e. the PTFE-layer 17b, is applied on a surface section 25 of the shaft section 16. The shaft section 16 is connected via additional screws 26 in a fixed, but detachable fashion to the second link 15. The second link 15 is here formed by a second housing part of the robot arm 2.

[0052] In case of the present exemplary embodiment of FIG. 3 the sealing lip 13 is configured as a double gasket. In case of the present exemplary embodiment of FIG. 3 the sealing lip 13 can however also be configured as a single sealing lip like in the embodiment according to FIG. 2.

[0053] The tread 17 is produced according to FIG. 3 by coating, particularly powder coating of the shaft section 16 of the second link 15 with a PTFE-material, particularly a PTFE-powder or a PTFE-powder mixture. To this extent the tread 17 is formed by a PTFE-layer 17b applied on the shaft section 16.

[0054] In case of the exemplary embodiment of FIG. 3 the sealing lip 13, and/or the double sealing lip of the shaft seal 12 and the tread 17 and/or the coating 17b are made from the same PTFE-material.

[0055] In case of the present exemplary embodiment of FIG. 3 the sealing lip 13 of the shaft seal 12 is also a sealing lip 13 without a tension spring, particularly a diaphragm shaft seal. In the embodiment shown in FIG. 3 the rotary joint of the robot arm 2 is a sealing lip 13 made from a PTFE-material and a tread 17 in the form of a coating 17b made from PTFE-material, the industrial robot 1 can be controlled via its robot control unit 10 for moving the robot arm 2 arranged in a cleanroom 18 (FIG. 1) such that any automatic movement of at least one rotary joint occurs maximally at an angular velocity at which the sealing lip 13 of the shaft seal 12 moves with a relative velocity in reference to the tread 17 which is below 1 meter per second (1 m/s).

[0056] While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.