WO2025201643A1

WO2025201643A1 - Link for industrial robot, and industrial robot

Info

Publication number: WO2025201643A1
Application number: PCT/EP2024/058352
Authority: WO
Inventors: Simon Hallstadius Linge
Original assignee: ABB Schweiz AG
Current assignee: ABB Schweiz AG
Priority date: 2024-03-27
Filing date: 2024-03-27
Publication date: 2025-10-02
Anticipated expiration: 2026-09-27

Abstract

The present invention relates to a link (20) for an industrial robot (10), the link comprising: a main body (21) having a first surface section (23), the first surface section comprising an opening (35) with a circumferential surface (36); a removable cover (30) configured to close the opening, the removable cover having a head portion (31) with an exterior surface (32) and a body portion (34) extending from the head portion in an axial direction (A); a sealing arrangement (40) for sealing the removable cover relative to the opening; a connector coupling (50) having a connector part (52) arranged on the body portion and a corresponding connector part (54) arranged at, or on, the circumferential surface of the opening; and wherein the connector part is adapted for rotational engagement with the corresponding connector part to form a sealed connection between the removable cover and the first surface section.

Description

LINK FOR INDUSTRIAL ROBOT, AND INDUSTRIAL ROBOT

Technical Field

The present invention generally relates to industrial robots. In particular, the present invention relates to a link for an industrial robot, as well as an industrial robot comprising such a link.

Background

In certain processing environments, maintaining a high level of hygiene is imperative. These environments often involve handling food, beverages, or pharmaceuticals using industrial robots. Any lapse in hygiene within such environments can lead to severe consequences. Therefore, it is customary to conduct thorough cleaning of the robot and its immediate vicinity on a daily basis.

A notable challenge in maintaining such hygiene standards is the exterior design of the components making up the robot, which typically comprises one or more links and joints. Some components, such as covers, are attached by bolting, requiring several bolts to ensure a sufficient and evenly distributed sealing force. This design often results in nooks and corners where dirt, bacteria, or other unwanted materials can accumulate. Although hygienic bolts are used on flat surfaces to mitigate this issue in industrial applications, these bolts themselves are not easily cleaned. In applications where hygiene is critical, the bolts require washing down with high-pressure, high-temperature water from multiple angles, which is a challenging and time-consuming task.

Furthermore, for certain manipulator arrangements, several lids are necessary for mounting purposes. The cleaning challenges associated with bolts are exacerbated by the number of covers required, each mounted in different orientations across the manipulator. Given these challenges, there is a need to further develop the exterior design of the robot and its surfaces so as to diminish the necessity for such extensive cleaning or at least to facilitate a more efficient cleaning process.

Summary

In view of the above, it would be desirable to further enhance the hygiene and cleanliness of robots, such as industrial robots operating in environments requiring high sanitary standards, by more seamlessly integrating components, such as covers, with the robot link(s).

According to a first aspect of the present invention, there is provided a link for an industrial robot. The link comprises a main body having a first surface section. The first surface section comprises an opening with a circumferential surface. Moreover, the industrial robot comprises a removable cover configured to close the opening. The removable cover comprises a head portion with an exterior surface and a body portion extending from the head portion in the axial direction. The industrial robot further comprises a sealing arrangement for sealing the removable cover relative to the opening. Moreover, the industrial robot comprises a connector coupling having a connector part arranged on the body portion of the removable cover and a corresponding connector part arranged at, or on, the circumferential surface of the opening. Further, the connector part is adapted for rotational engagement with the corresponding connector part to form a sealed connection between the removable cover and the first surface section.

The invention is at least partly based on the insight that the challenges of maintaining hygiene and preventing contamination in industrial robots, especially in robots utilized in sensitive environments like food, beverage, and pharmaceutical processing, can be addressed by rethinking the connection and sealing mechanisms for covers for robots, such as robot links.

The configuration of the removable cover with the arrangement of connector coupling facilitates easy access for maintenance or modification, while ensuring that the structural integrity of the link is preserved. Also, the connector coupling provides a more secure and precise connection compared to other prior art covers, thus enhancing the ease of assembly and disassembly. This advantage maybe particularly beneficial for maintenance or replacement activities, as it allows for swift and efficient handling of the components without compromising safety or hygiene. Further, the configuration of the removable cover allows for a tight fit and a reliable closure, which provides protection for the internal components of the robots from external contaminants. In addition, the sealing arrangement contributes to preventing leakage and the ingress of contaminants, thereby safeguarding the durability of the link and its components.

Typically, the connector part is configured to be rotationally engaged with the corresponding connector part until an outermost radial surface region of the head portion is planar with the first surface section of the main body. This means that the surfaces are level or lie on the same plane. Such configuration provides a cleaner-friendly arrangement between the removable cover and the main body, enhancing ease of maintenance and aesthetic integration.

Thus, the exterior surface of the head portion may typically comprise the outermost radial surface region. The removable cover may also have an extension in the axial direction and an extension in a radial direction.

The exterior surface of the head portion of the removable cover may further comprise one or more tool-interacting portions configured to interact with a tool for rotating the removable cover in relation to the opening. Hereby, the removable cover is configured to be rotationally manipulated to a closed position forming the sealed connection. The arrangement of one or more tool-interacting portions allows for easy and efficient manipulation of the cover with standard tools, reducing downtime and simplifying maintenance procedures.

The one or more tool-interacting portions may be provided in the form of recesses distributed around the exterior surface. Recesses offer a secure grip for tools, minimizing the risk of slippage and damage during operation. The one or more tool-interacting portions may be provided in the form of recesses distributed around an inner radial region of the exterior surface.

Alternatively, the one or more tool-interacting portions may be provided in the form of protruding portions distributed around the exterior surface. Protruding portions can be easily engaged by various tool types, offering flexibility in maintenance operations. The one or more tool-interacting portions may be provided in the form of protruding portions distributed around the inner radial region.

The body portion may comprise an outer circumferential surface. The outer circumferential surface of the body portion may comprise the connector part and the circumferential surface of the opening may comprise the corresponding connector part. Such configuration ensures a consistent and robust mechanical connection.

The connector part may comprise a threaded portion and the corresponding connector part may comprise a corresponding threaded portion. Threaded connections provide adjustable tightness and secure attachment, allowing for customized installation according to given requirements.

Alternatively, the connector coupling may be a bayonet-type coupling, wherein one of the connector part and the corresponding connector part comprises a radial projection and the other one comprises a bayonet-type connection slot for accommodating a part of the radial projection. Bayonettype couplings offer quick and secure fastening and release, enhancing the efficiency of assembly and maintenance operations.

The sealing arrangement may be a circumferential sealing arrangement arranged around the removable cover. A circumferential seal provides improved protection against leaks, ensuring the integrity of the internal environment.

The sealing arrangement may be configured to provide a liquid-tight connection in a radial direction between the removable cover and the opening when the removable cover is rotationally engaged to the main body of the link. Ensuring a liquid-tight seal may prevent, or at least reduce the risk of fluid damage to internal components and may be particularly useful for operations in harsh environments.

The main body may further comprise a second surface section with a corresponding opening, and further having a corresponding circumferential surface. The link may comprise an additional removable cover configured to close the corresponding opening.

The main body may comprise an exterior main surface including the first surface section and an intermediate section interconnecting the first surface section and the second surface section. A unified main body design with interconnected surface sections offers enhanced structural strength and stability.

The intermediate section maybe planar with the first surface section and the second surface section. The planar alignment of these sections may facilitate a streamlined design, reducing potential catch points and simplifying the cleaning process.

According to a second aspect of the invention, there is provided an industrial robot comprising a link according to the first aspect of the invention. The second aspect of the invention may seek to solve the same problem as described for the first aspect of the invention. Thus, effects and features of the second aspect of the invention are largely analogous to those described above in connection with the first aspect of the invention.

The industrial robot typically comprises at least one joint. In some examples, the industrial robot comprises a plurality of joints. As such, the industrial robot may comprise a first joint, a second joint, wherein the link is configured to interconnect the first joint and the second joint.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.

Brief Description of the Drawings

These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing example embodiments of the invention, wherein:

Fig. 1 is a perspective view of an industrial robot according to an example;

Figs. 2 and 3 schematically illustrate an example of a component of the robot in Fig. 1 according to an example;

Figs. 4 to 5 schematically illustrate an example of a removable cover for the robot in Figs. 1 to 3;

Fig. 6 schematically illustrates another example of a removable cover for the robot in Figs. 1 to 3; and

Fig. 7 schematically illustrates another example of the removable cover for the robot in Figs. 1 to 3.

Detailed Description

In the present detailed description, various embodiments of an industrial robot are mainly described with reference to an industrial robot comprising a plurality of links. However, the described industrial robot is suitable for any type of industrial robot. For ease of reference, the industrial robot may simply be denoted as the robot. The same or similar reference numerals will be used to denote the same or similar structural features.

Turning now to Fig. 1, which schematically represents a first perspective side view of an exemplary industrial robot 10. The industrial robot 10 may for example operate in a hygienic environment to handle food, beverages or pharmaceuticals. As illustrated in Fig. i, the industrial robot io comprises a base 12. The base 12 is the foundation of the robot 10 and configured to provide stability during operation of the robot 10. The base 12 is often designed to allow for easy integration into existing production lines. Fig. 1 also denotes an exterior environment 11 outside of the industrial robot 10.

As schematically depicted in Fig. 1, the robot 10 comprises a plurality of links 20. Each one of the links 20 provides operational integration and functionality for the robot 10. The links 20 can be rotatably arranged relative to each other, as illustrated in Fig. 1. In addition, at least one of the links 20 is typically rotatably arranged to relative to the base 12. It should be noted that, while the robot 10 may in some examples only comprise a single link 20, the robot 10 typically comprises a plurality of links 20, such as a first link 20a, a second link 20a etc.

The links 20 are interconnected to each other by one or more joints 18. In Fig. 1, the robot 10 comprises a plurality of joints 18, such as a first joint 18, 18a, a second joint 18, 18b etc. For example, the first link 20, 20a is rotatably arranged relative to the second link 20, 20b via the first joint 18, 18a. Each one of the links 20 is typically also configured to be rotatable around a corresponding axis of rotation 16, as illustrated in Fig 1. It should be noted that, while the robot 10 may in some examples only comprise a single axis of rotation 16, the robot 10 typically comprises a plurality of axes of rotation 16, such as a first axis of rotation 16, a second axis of rotation 16 etc. In this manner, the links 20, joints 18 and axes of rotation 16 collectively form a manipulator arrangement, in which the links 20, joints 18 provide one or more robot arms.

Each one of the links 20 further comprises a main body 21, as illustrated in Fig. 1. Typically, the main body 21 of the link 20 extends at least between adjacent joints 18. For other links 20, the main body 21 serves as an end part of the robot 10. Thus, the main body 21 is only connected to a single joint at one end thereof. Other extensions of the main body 21 of the link 20 are also conceivable, as may be gleaned from Fig. 1. Turning again to the links 20 of the robot 10, one example of the link 20 in Fig. 1 is further illustrated in Figs. 2 and 3. As schematically illustrated in Figs. 2 and 3, the main body 21 comprises an exterior main surface 22. The exterior main surface 22 comprises at least a first surface section 23. In Figs. 2 and 3, the exterior main surface 22 further comprises a second surface section 24 and an intermediate section 25. The intermediate section 25 extends between the first surface section 23 and the second surface section 24. To this end, the main body 21 of the link 20 comprises the exterior main surface 22, which includes the first surface section 23, the second surface section 24 and the intermediate section 25 interconnecting the first surface section 23 and the second surface section 24. Moreover, in this example, as illustrated e.g. in Fig. 2, the intermediate section 25 is planar with the first surface section 23 and the second surface section 24. For other links 20, the intermediate section 25 is arranged inclined with an angle to the first surface section 23 and the second surface section 24. It should be noted that even in examples where the intermediate section 25 is planar with the first surface section 23 and the second surface section 24, each one of the first surface section 23, the second surface section 24 and the intermediate section 25 may comprise one or more curvilinear surface regions.

In order to allow for assembling and disassembling of some of the components of the robot 10, one or more of the links 20 are provided with one or more openings 35. Each one of the openings 35 is covered and closed by a corresponding removable cover 30, as e.g. illustrated in Fig. 1, in conjunction with Figs. 2 and 3. By the arrangement of the opening 35 and the corresponding removable cover 30, it becomes possible to access gearboxes and joints of the robot 10, and also to allow for interconnecting the links 20 to each other, or interconnecting one of the links 20 to the base 12. For example, one of the links 20 can be mounted to a gearbox of one joint 18 by inserting a tool device through the opening 35 covered by the removable cover 30. Alternatively, two links 20 can be rotationally mounted to each other through one or more openings 35. Moreover, the arrangement of the opening 35 and the corresponding removable cover 30 allows for accessing cables and the like. For example, through the openings 35 covered by the removable covers 30, a cable harness may be manually accessed to be routed inside of the robot 10, e.g. between the base 12 and one of the links 20.

As mentioned above, the removable cover 30 is configured to close the opening 35. The purpose of the cover 30 is to prevent contamination of the environment inside the robot 10. The removable cover 30 also provides for protecting the environment inside the robot 10 during a washdown process.

Turning again to Figs. 2 and 3, the exterior main surface 22 of the main body 21 is here an exterior continuous main surface. Moreover, the exterior main surface 22 faces the exterior environment 11 being outside of the robot 10. The exterior main surface 22 is here essentially planar. Other designs and extensions of the main body 21 may also be possible, as schematically illustrated in e.g. Fig. 1.

The closure of the removable cover 30 relative to the opening 35 will now be further described in relation to Figs. 4 to 6. Figs. 4 to 5 depict one example of the closure of the removable cover 30 relative to the opening 35, while Fig. 6 schematically illustrates another example of the closure of the removable cover 30 relative to the opening 35.

Turning initially to Fig. 4, there is depicted a disassembled state 70 of the removable cover 30 relative to the main body 21 of the link 20. In Fig. 5, there is depicted a connected state 72 of the removable cover 30 relative to the main body 21 of the link 20.

The removable cover 30 has an extension in an axial direction A and an extension in a radial direction R. The axial direction A is essentially perpendicular to the radial direction R. The removable cover 30 further has a center axis Ac, extending in the axial direction A. The removable cover 30 is configured to be rotatable about the center axis Ac. Also, the removable cover 30 has a circumferential direction C. The removable cover 30 is here substantially circular. Analogously, the opening 35 is here substantially circular. The shape of the opening 35 resembles the shape of the removable cover 30. In one example, the shape of the opening 35 is complementary to the shape of the removable cover 30. The opening 35 is an integral part of the first surface section 23. Hence, the first surface section 23 comprises the opening 35. The opening 35 defines a through hole extending through the first surface section 23.

The extension of the through hole of the opening 35 is schematically illustrated in Figs. 4 to 6. As depicted in Figs. 4 to 6, the opening 35 has a circumferential surface 36 surrounding the opening 35. The circumferential surface 36 extends in the axial direction A and in the circumferential direction C of the opening 35.

For completeness, where the link 20 comprises the second surface section 24, as shown in Figs. 2 and 3, the second surface section 24 comprises a corresponding opening 35. The corresponding opening 35 typically extends through the second surface section 24. In addition, in such example, the link 20 comprises an additional removable cover 30 configured to close the corresponding opening 35.

The removable cover 30 is configured to be rotationally displaceable in the axial direction A between the disassembled state 70, in which the removable cover 30 is separated from the main body 21, and the connected state 72, in which the removable cover 30 is sealingly connected to the main body 21. More specifically, the removable cover 30 is configured to be rotatable about its center axis Ac and moveable in the axial direction A. The removable cover 30 is configured to be moveable between the disassembled state 70 and the connected state 72 relative to the opening 35, as illustrated in Figs. 4 and 5.

The removable cover 30 can be designed in several different manners. In one example, as illustrated in Figs. 4 and 5, the removable cover 30 comprises a head portion 31. The head portion 31 here further comprises an exterior surface 32. The exterior surface 32 extends in the radial direction R of the removable cover 30.

As depicted in Figs. 4 and 5, the exterior surface 32 comprises an outermost radial surface region 33. The outermost radial surface region 33 is the outermost region of the exterior surface 32 in the radial direction R in relation to a center of the removable cover 30, as defined by the center axis Ac, which is illustrated in Figs. 4 and 5.

The head portion 31 has a substantially circular cross-section. The head portion 31 should be designed to fit within the opening 35, as illustrated in Figs. 4 and 5.

The removable cover 30 further comprises a body portion 34. The body portion 34 extends from the head portion 31 in the axial direction A of the removable cover 30. Moreover, the body portion 34 comprises an outer circumferential surface 38. The outer circumferential surface 38 extends in the circumferential direction C about the body portion 34. The outer circumferential surface 38 further extends a substantial part in the axial direction A.

The body portion 34 is rotationally insertable into the opening 35. The body portion 34 has a substantially circular cross-section. The body portion 34 is here also designed to fit within the opening 35, as illustrated in Figs. 4 and 5. In the connected state 72, the body portion 34 is arranged to fully extend into the hole of the opening 35. Typically, as illustrated in Figs. 4 and 5, the body portion 34 has a radial extension that is smaller than the radial extension of the head portion 31.

The removable cover 30 is held in the connected state 72 relative to the opening 35 by means of a connector coupling 50. The connector coupling 50 allows for a secure closure connection of the removable cover 30 to the main body 21 of the link 20. The connector coupling 50 can be designed in several different manners. Figs. 4 and 5 illustrate one example of a connector coupling 50, while another example of a connector coupling 50 is illustrated in Fig. 6.

To this end, the removable cover 30 is adapted for rotational engagement with the opening 35 by means of the connector coupling 50. The connector coupling 50 further allows for rotational insertion of the removable cover 30 into the opening 35. As such, the removable cover 30 is adapted for rotational insertion into the opening 35. When the removable cover 30 is rotational inserted into the opening 35, as depicted in Fig. 5, the removable cover 30 is disposed in the opening 35.

As illustrated in Figs. 4 and 5, the connector coupling 50 comprises a connector part 52 arranged on the body portion 34 of the removable cover 30. Thus, the connector part 52 is an integral part of the removable cover 30. In addition, the connector coupling 50 comprises a corresponding connector part 54 arranged on the circumferential surface 36 of the opening 35. Thus, the corresponding connector part 54 is an integral part of the main body 21. Accordingly, the connector coupling 50 is an integral part of the link 20.

In one example, as illustrated in Figs. 4 and 5, the circumferential surface 36 comprises the corresponding connector part 54. By way of example, an axial extension of the corresponding connector part 54 is defined by the axial extension of the circumferential surface 36. In other examples, the corresponding connector part 54 is arranged along an axial part of the circumferential surface 36. Yet, in other examples, as e.g. illustrated in Fig. 6, the corresponding connector part 54 is defined as a recess in the circumferential surface 36. As such, the corresponding connector part 54 is located at, or on, the circumferential surface 36 of the opening 35. The corresponding connector part 54 can thus be located at, or on, the circumferential surface 36 of the opening 35 in several different ways.

The connector coupling 50 is configured to permit a displacement of the removable cover 30 from the disassembled state 70 to the connected state 72 by a rotational movement of the removable cover 30 in the circumferential direction C. In Fig. 5, the configuration of the connector coupling 50 allows for a rotational engagement until the outermost radial surface region 33 of the head portion 31 is planar with the first surface section 23 of the main body 21.

The configuration of the connector coupling 50 typically allows for a rotational engagement until the outermost radial surface region 33 of the head portion 31 becomes essentially flush with the first surface section 23, indicating a planar state P in Fig. 5.

In order to provide the sealed connection between the removeable cover 30 and the opening 35, there is provided a sealing arrangement 40, which is illustrated in e.g. Figs. 4 and 5. The sealing arrangement 40 is configured to seal the removable cover 30 relative to the opening 35.

As such, by the arrangement of the connector part 52 adapted for rotational engagement with the corresponding connector part 54 in cooperation with the sealing arrangement 40, the removable cover 30 and the first surface section 23 form the sealed connection. Typically, the removable cover 30 and the first surface section 23 form the sealed connection when the outermost radial surface region 33 of the head portion 31 is planar with the first surface section 23 of the main body 21.

The sealing arrangement 40 can be provided and arranged in several different manners. In Figs. 4 and 5, the sealing arrangement 40 is a circumferential sealing arrangement arranged around the removable cover 30. For example, the sealing arrangement 40 is a circumferential sealing arrangement arranged completely circumferentially around the body portion 34 of the removable cover 30. The circumferential sealing arrangement can be provided as an annular sealing ring, such as a conventional O-ring. The material of the sealing arrangement 40 is typically of a flexible material, such as a suitable polymeric material or a rubber material.

To this end, in Figs 4 and 5, the sealing arrangement 40 is an annular sealing ring disposed on the outer circumferential surface 38 of the body portion 34, and further arranged in-between the exterior surface 32 and the connector part 52, as seen in the axial direction A of the removable cover 30.

In the connected state 72, as shown in Fig. 5, the sealing arrangement 40 provides a liquid-tight connection in the radial direction R between the removable cover 30 and the opening 35. As such, the sealing arrangement 40 is configured to provide a liquid-tight connection in the radial direction R between the removable cover 30 and the opening 35 when the removable cover 30 is rotationally engaged to the main body 21 of the link 20.

In Figs. 4 and 5, the sealing arrangement 40 is an integral part of the removable cover 30. In other examples, the sealing arrangement 40 is an integral part of the main body 21 of the link 20. For examples, the sealing arrangement 40 can be pre-attached to the opening 35. As such, the sealing arrangement 40 is an integral part of the link 20.

Turning again to the connector coupling 50 of Figs. 4 and 5. As schematically illustrated in Figs. 4 and 5, the connector coupling 50 is here a circular connector coupling. As such, the link 20 comprises a circular connector part 52 arranged on the body portion 34 of the removable cover 30 and a corresponding circular connector part 54 arranged at, or on, the circumferential surface 36 of the opening 35. Figs. 4 and 5 illustrate the circular connector coupling 50 in the form of a threaded connector coupling. For example, the connector part 52 comprises a threaded portion and the corresponding connector part 54 comprises a corresponding threaded portion.

The circular connector part 52 is adapted for rotational engagement with the corresponding circular connector part 54 until the outermost radial surface region 33 of the head portion 31 is planar with the first surface section 23 of the main body 21, whereby the removable cover 30 and the first surface section 23 form the sealed connection.

Typically, the outer circumferential surface 38 of the body portion 34 comprises the connector part 52 and the circumferential surface 36 of the opening 35 comprises the corresponding connector part 54. Accordingly, the circumferential surface 36 surrounding the opening 35 comprises the corresponding connector part 54.

Moreover, as depicted in Fig. 4, the removable cover 30 is set in the sealed connection relative to the opening 35 by means of a tool 80. The tool 80 can e.g. be a rotatable tool using vacuum for manipulating the removable cover 30 in relation to the opening 35.

In order for the removable cover 30 to engage with the tool 80, the head portion 31 of the removable cover 30 comprises one or more tool-interacting portions 60, as shown in Fig. 4. In Fig. 4, the exterior surface 32 of the head portion 31 comprises a plurality of tool-interacting portions 60. The toolinteracting portions 60 are configured to interact with the tool 80, allowing the removable cover 30 to rotate about its center axis Ac. In addition, the tool-interacting portions 60 are adapted to allow for a rotational movement of the removable cover 30 between the disassembled state 70 and the connected state 72. As such, the removable cover 30 is configured to engage with the tool 80 to facilitate the rotational movement of the removable cover 30 between the disassembled state 70 and the connected state 72.

The tool-interacting portions 60 maybe provided as recesses, as illustrated in Fig. 4, or as protruding portions, as illustrated in Fig. 7. The tool-interacting portions 60 are typically distributed around the exterior surface 32 of the main body 21 of the removable cover 30. Accordingly, in Fig. 4, the one or more tool-interacting portions 60 are provided in the form of recesses distributed around the exterior surface 32. In Fig. 7, the one or more toolinteracting portions 60 are provided in the form of protruding portions distributed around the exterior surface 32. The one or more tool-interacting portions 60 may be symmetrical or asymmetrical distributed around the center of the removable cover 30, such as around the center axis Ac.

It should be noted that the tool 80 is typically also configured to insert the removable cover 30 into the opening 35. More specifically, the tool 80 is typically configured to insert the removable cover 30 into the opening 35 until an initial engagement is obtained between the connector part 52 and the corresponding connector part 54.

In some examples, although not illustrated, the exterior surface of the head portion 31 comprises a single tool-interacting portion 60 configured to interact with the tool 80 so as to rotationally move the removable cover between the disassembled state 70 and the connected state 72.

It should also be noted that when the removable cover 30 is in the connected state 72 relative to the opening 35, the removable cover 30 is arranged to form the sealed connection with the first surface section 23 of the main body 21 of the link 20 due to the combination of the connector coupling 50 and the sealing arrangement 40. Moreover, in the connected state 72, the removable cover 30 typically provides the liquid-tight connection relative the opening 35 due to the configuration of the sealing arrangement 40.

Fig. 6 shows another example of a connector coupling 50. In Fig. 6, the connector coupling 50 is provided in the form of a bayonet-type coupling mechanism. As such, the connector coupling 50 is a bayonet-type coupling, wherein one of the connector part 52 and the corresponding connector part 54 comprises a radial projection 55 and the other one comprises a bayonettype connection slot 56 for accommodating a part of the radial projection 55. In Fig. 6, the connector part 52 of the body portion 34 comprises the radial projection 55 and the corresponding connector part 54 comprises the bayonet-type connection slot 56. As illustrated in Fig. 6, the bayonet-type connection slot 56 is disposed on the circumferential surface 36 of the opening 35. The bayonet-type connection slot 56 is adapted to accommodate the radial projection 55, or at least adapted to accommodate a part of the radial projection 55. The bayonet-type connection slot 56 comprises an entrance 57 for the radial projection 55, facilitating the insertion and removal of the removable cover 30. The bayonet-type connection slot 56 also includes a path portion 58 with an abutment surface 59. The path portion 58 typically extends from the entrance 57 in the axial direction A and further in the circumferential direction C until the abutment surface 59. In this manner, there is provided another example of a connector coupling 50 for the removable cover 30, in which the radial projection 55 of the connector part 52 is adapted for rotational engagement with the bayonet-type connection slot 56 of the corresponding connector part 54 until the outermost radial surface region 33 of the head portion 31 is planar with the first surface section 23 of the main body 21. Hereby, the removable cover 30 and the first surface section 23 form the sealed connection. It should also be readily appreciated that the opposite arrangement of the radial projection 55 and the bayonet-type connection slot 56 is possible, in which the radial projection 55 is part of the corresponding connector part 54 and the bayonet-type connection slot 56 is part of the connector part 52.

Also, in Fig. 6, the link 20 comprises the sealing arrangement 40. In this example, the sealing arrangement 40 is a circumferential sealing arrangement in the form of an annular sealing ring. The sealing arrangement 40 is part of the outer circumferential surface 38 of the body portion 34. As mentioned above in relation to Figs. 4 and 5, the sealing arrangement 40 can likewise be a separate part that is positioned on the outer circumferential surface 38 of the body portion 34. The sealing arrangement 40 is here arranged between the main body 31 and the connector port 52, ensuring the integrity of the seal. Typically, the sealing arrangement 40 should at least be arranged between the exterior surface 32 of the main body 31 and the connector port 52.

Even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. Also, it should be noted that parts of the system and method may be omitted, interchanged or arranged in various ways, the system and method yet being able to perform the functionality of the present invention.

Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A link (20) for an industrial robot (10), the link (20) comprising:

- a main body (21) having a first surface section (23), the first surface section comprising an opening (35) with a circumferential surface (36);

- a removable cover (30) configured to close the opening, the removable cover having a head portion (31) with an exterior surface (32) and a body portion (34) extending from the head portion in an axial direction (A);

- a sealing arrangement (40) for sealing the removable cover relative to the opening;

- a connector coupling (50) having a connector part (52) arranged on the body portion and a corresponding connector part (54) arranged at, or on, the circumferential surface of the opening; and wherein the connector part is adapted for rotational engagement with the corresponding connector part to form a sealed connection between the removable cover and the first surface section.

2. The link according to claim 1, wherein the connector part is configured to be rotationally engaged with the corresponding connector part until an outermost radial surface region of the head portion is planar with the first surface section of the main body.

3. The link according to claim 1 or claim 2, wherein the exterior surface of the head portion further comprises one or more tool-interacting portions (60) configured to interact with a tool (80) for rotating the removable cover in relation to the opening.

4. The link according to claim 3, wherein the one or more tool-interacting portions are provided in the form of recesses distributed around the exterior surface.

5. The link according to claim 3, wherein the one or more tool-interacting portions are provided in the form of protruding portions distributed around the exterior surface.

6. The link according to any one of the preceding claims, wherein an outer circumferential surface of the body portion comprises the connector part and the circumferential surface of the opening comprises the corresponding connector part.

7. The link according to any one of the preceding claims, wherein the connector part comprises a threaded portion and the corresponding connector part comprises a corresponding threaded portion.

8. The link according to any one of the preceding claims 1 to 6, wherein the connector coupling is a bayonet-type coupling, and wherein one of the connector part and the corresponding connector part comprises a radial projection (55) and the other one comprises a bayonet-type connection slot (56) for accommodating a part of the radial projection.

9. The link according to any one of the preceding claims, wherein the sealing arrangement is a circumferential sealing arrangement arranged around the removable cover.

10. The link according to any one of the preceding claims, wherein the sealing arrangement is configured to provide a liquid-tight connection in a radial direction between the removable cover and the opening when the removable cover is rotationally engaged to the main body of the link.

11. The link according to any one of the preceding claims, wherein the main body further comprises a second surface section (24) with a corresponding opening, and further having a corresponding circumferential surface, and wherein the link comprises an additional removable cover configured to close the corresponding opening.

12. The link according to claim 11, wherein the main body comprising an exterior main surface (22) including the first surface section and an intermediate section (25) interconnecting the first surface section and the second surface section.

13. The link according to claim 12, wherein the intermediate section is planar with the first surface section and the second surface section.

14. An industrial robot (10) comprising a link (20) according to any of the preceding claims.

15. Industrial robot according to claim 14, further comprising a first joint (18) and a second joint (18), wherein the link (20) is configured to interconnect the first joint (18) with the second joint (18).