SE1651498A1 - An industrial robot having an exterior surface that is self-cleaning and/or self-disinfecting and a method for providingsuch a surface - Google Patents

Abstract

An industrial robot (1) having an exterior surface (10), wherein the exterior surface is configured to be self-cleaning and/or self-disinfecting. The exterior surface may be covered in a liquid film (12) during operation of the robot. The liquid film may be an anti-bacterial liquid film. Further, the exterior surface (10) of the robot may be provided with a pattern of micro pores (16), and ozonated water may be continually pumped through the micro pores (16) and thereby a liquid film (12) is created on the exterior surface (10) of the robot.(Fig. 2)

Description

1 16195SE Draft 2016-11-15 AN INDUSTRIAL ROBOT HAVING AN EXTERIOR SURFACE THAT IS SELF-CLEANINGAND/OR SELF-DISINFECTING AND A METHOD FOR PROVIDING SUCH A SURFACE Technical field of the inventionThe present invention relates to a method for providing a self-cleaning and/or self-disinfecting exterior surface on an industrial robot. The invention further relates to an industrial robot having an exterior surface that is configured to be self-cleaning and/or self-disinfecting.

Background Industrial robots designed for handling open food in the protein industry (fish, poultry,meat and dairy), so called food-grade robots, are subject to strict hygiene requirementsinvolving daily washdown with high pressure spray and powerful chemical agents. Thewashdown process accounts for one entire working shift in a food processing facility, whichseverely reduces the productivity. lt also necessitates a sealed construction for the robot in aninert material such as stainless steel.

Daily washdown creates several problems. Firstly, sophisticated joint seals arerequired to withstand high pressure spraying, and chemical treatments necessitate the use of astainless steel exterior. The former is a price driver given the fine tolerance and surface finishrequirements of suitable seals, while the latter results in cooling problems since stainless steelis a poor thermal conductor and convective cooling is ineffective within the confines of thehermetically sealed construction. A further problem is the fact that contaminants, including livebacteria that are removed from the robot, become aerosolized and can spread throughout thefacility. This, together with the fact that the washdown process puts the robot out of action forone whole shift (at least 5-6 hours) every day, calls into question the suitability of pressure washing as an appropriate cleaning method for a food-grade robot.

Summary of the invention An object of the invention is to provide an improved industrial robot suitable for use asa food-grade robot and by which at least some of the above problems are solved.

The object is achieved by an industrial robot according to appended claim 1 and themethod according to appended claim 7.

The invention proposes a new concept based on continual self-cleaning withoutspraying or chemical agents. As a by-product, this also solves the cooling problem arising fromthe use of a hermetically sealed, stainless steel robot design.

According to a first aspect of the invention, there is provided an industrial robot havingan exterior surface, wherein the exterior surface is configured to be self-cleaning and/or self- disinfecting. This has the advantage that the requirements for manual cleaning can be reduced 2 16195SE Draft 2016-11-15 and possibly even eliminated. Preferably the entire exterior surface is configured to be self-cleaning and/or self-disinfecting According to one embodiment the exterior surface may be covered in a liquid filmduring operation of the robot. By providing a liquid film, i.e. a film of a liquid, there will be aconstant Washing of the exterior surface of the robot, since the liquid film will continuously dripoff the exterior surface. Preferably the entire exterior surface is covered by a liquid film.

According to one embodiment the exterior surface may be covered in an anti-bacterialliquid film during operation of the robot. By providing the liquid film as a film of an anti-bacterialliquid will be provided for disinfection of the exterior surface of the robot.

According to another embodiment, the exterior surface of the robot may be providedwith micro pores. The micro pores Will make it possible to supply the liquid for the liquid filmfrom a source inside the robot and onto the exterior surface via the micro pores. The micropores are arranged in a pattern that is configured such that droplets of liquid that exit throughthe micro pores will form a liquid film on the exterior surface of the robot. The pattern of micropores is therefore usually relatively dense.

According to another embodiment, ozonated water may be continually pumped throughthe micro pores and thereby a liquid film is created on the exterior surface of the robot. Byproviding the liquid for the liquid film as ozonated water is obtained the advantage that nochemical agents need to be used. Ozonated water, i.e. ozone dissolved in water, has a powerfulantimicrobial effect. Furthermore, by using water is achieved a cooling effect since the watercan remove heat from inside the robot.

According to a further embodiment, the industrial robot may be covered by a doubleWall construction comprising a watertight inner wall and an outer wall comprising micro pores,and said outer wall comprising said exterior surface of the robot, wherein a space is createdbetween the inner wall and the outer wall, wherein the robot further comprises tubing that isconfigured to transport an anti-bacterial liquid into said space, out through the micro pores andonto the exterior surface, and that a pump device is provided for pumping the anti-bacterialliquid through the tubing, into said space and out through the micro pores, thereby providing theliquid film.

Preferably, the entire exterior surface of the robot is covered by the liquid film duringoperation of the robot.

According to one embodiment, the industrial robot is a food-grade robot.

According to a second aspect of the invention, there is provided a method for providinga self-cleaning and/or self-disinfecting exterior surface on an industrial robot, comprisingproviding a liquid film on the exterior surface of the robot.

According to one embodiment, the method may comprise providing the exterior surface of the robot with a pattern of micro pores and pumping a liquid through the micro pores and onto 3 16195SE Draft 2016-11-15 the exterior surface. The liquid may be continually pumped through the micro pores, at leastduring operation of the robot.According to a further embodiment, the method may comprise providing the liquid filmby means of an anti-bacterial liquid.According to yet another embodiment, the method may comprise that the liquid film isprovided by means of a liquid comprising ozonated water.To summarise, the following advantages are offered by the invention:- Reduced manual cleaning requirements since robot will largely self-clean- Reduced risk of resistant bacteria development since chemical agents are not used- Reduced risk of spreading of bacteria since there is no risk of bacteria becomingaerosolized- Cost savings since hot water is not required- Greater up-time - robot can work 24 hours per day- lncreased robot performance (faster cycles/higher payloads) due to enhanced cooling- Reduces total cost of ownership (greater up-time + less cleaning effort)Further features and advantages of the invention will also become apparent from the following detailed description of embodiments.

Brief description of the drawings The invention will now be described in more detail, with reference being made to theenclosed schematic drawings illustrating different aspects and embodiments of the invention,given as examples only, and in which: Fig. 1 shows an embodiment of an industrial robot, Fig. 2 shows a view that is an enlargement of a part of the industrial robot of Fig. 1,which part is marked A in Fig. 1, Fig. 3 shows a view that is an enlargement of a part of the industrial robot in Fig. 2,which part is marked B in Fig. 2, and Fig. 4 is a schematic diagram of an embodiment of a method.

Elements that are the same or represent corresponding or equivalent elements have been given the same reference numbers in the different figures.

Detailed description ln Fig. 1 and Fig. 2 is schematically shown an industrial robot 1 having an exteriorsurface 10, which exterior surface is configured to be self-cleaning and/or self-disinfecting. Therobot in the illustrated embodiment comprises arm links 3 and joints 5 between the arm links.

The marked area A shows part of the robot in a cut away view, which is also shown in Fig. 2, in 4 16195SE Draft 2016-11-15 an enlarged view. The industrial robot would also include a robot base structure and a robotcontroller, which are not shown in the figure.

As can be seen in the more detailed view in Fig. 2, the exterior surface 10 of the robotis covered in a liquid film 12. ln the figure, the liquid film 12 is illustrated as droplets 14. Theliquid film may be produced by means of a liquid that is anti-bacterial. ln order to obtain theliquid film 12, the exterior surface 10 of the robot may be provided with a pattern of micro pores16, through which the liquid seeps out from a liquid source internally of the robot. When theliquid seeps out through the many micro-pores 16, droplets 14 are formed and these dropletsresult in a liquid film 12 that covers the exterior surface 10 of the robot. Preferably the entireexterior surface 10 of the robot is covered by the liquid film 12, at least during operation of therobot.

The liquid film 12 is preferably produced by a liquid and preferably an anti-bacterialliquid such as ozonated water. The liquid is pumped through the micro pores 16 and thereby aliquid film is created on the exterior surface of the robot. The liquid is preferably pumpedcontinually, at least during operation of the robot.

An example of how the exterior surface 10 of the robot may be achieved and furtherdetails are more clearly shown in Fig. 2 and Fig. 3. The industrial robot 1 is covered by a doublewall construction 20 comprising a watertight inner wall 22 and an outer wall 24 comprising micropores 16. The outer wall 24 comprises said exterior surface 10 of the robot. A void space 26 iscreated between the inner wall 22 and the outer wall 24. The robot further comprises tubing 28that is configured to transport the liquid into said space 26, out through the micro pores 16 andfurther onto the exterior surface 10. The inner wall 22 is provided with connection devices 29 forconnection of the tubing 28 such that liquid can flow from the tubing and into the space 26. Apump device, not shown, may be provided for pumping the anti-bacterial liquid through thetubing 28, into said space 26 and out through the micro pores 16.

The inner wall 22 and the outer wall 24 are connected physically to one another atregular intervals by many small pillars of material. lt is envisioned that the double wallcomponents, i.e. the housings 7 for the joints 5 and arm links 3, are made in one piece using anadditive manufacturing method such as selective laser melting, in which the density of the metaldeposition can easily be varied from fully airtight to porous. This approach is already used forthe manufacture of e.g. turbine blades where internal cooling passages are required. Thedouble wall components are joined together by joint seals 30. ln the illustrated example of Figs. 1-3, is also shown how the the present invention canprovide a means of cooling the motors 32 and gearboxes 34 inside the robot 1. By mountingthese transmission components such that they make intimate contact with the inner wall 22 ofthe joint housing 7, the unwanted heat will be carried away by the flow of water through to the exterior surface 10 of the robot. ln regions directly adjacent to the hot components, the water 5 16195SE Draft 2016-11-15 will evaporate after a short time on the exterior surface 10 rather than dripping off. Byappropriate adjustment of flowrate in response to data from temperature sensors within therobot it would be possible to maintain an unbroken outer liquid film irrespective of the robotworkload. A further advantage would be that under standstill conditions, the incoming watertemperature could be deliberately increased to maintain a constant internal temperature insidethe robot. This would prevent the formation of an under pressure as the robot cools, which tendto draw in water from outside via the joint seals thus increasing the risk of bearing damage dueto corrosion and lubricant contamination. ln Fig. 4 is illustrated a schematic diagram of a method for providing a self-cleaningand/or self-disinfecting exterior surface on an industrial robot. The method comprises the step ofproviding a liquid film on the exterior surface of the robot.

According to one embodiment, the method may comprise providing the exterior surfaceof the robot with a pattern of micro pores and pumping a liquid through the micro pores and ontothe exterior surface. The liquid film may be provided by means of an anti-bacterial liquid, suchas ozonated water.

The invention shall not be considered limited to the illustrated embodiments, but can bemodified and altered in many ways, as realised by a person skilled in the art, without departing from the scope defined in the appended claims.

Claims (10)

6 16195SE Draft 2016-11-15 Patent Claims

1. An industrial robot (1) having an exterior surface (10), wherein the exterior surface is configured to be self-cleaning and/or self-disinfecting.

2. The industrial robot according to claim 1, wherein the exterior surface (10) is covered in a liquid film (12) during operation of the robot.

3. The industrial robot according to claim 2, wherein the exterior surface (10) is covered in an anti-bacterial liquid film (12) during operation of the robot.

4. The industrial robot according to any one of the preceding claims, wherein the exterior surface (10) of the robot is provided with a pattern of micro pores (16).

5. The industrial robot according to claim 4, wherein ozonated Water is continually pumpedthrough the micro pores (16) and thereby a liquid film (12) is created on the exterior surface (10) of the robot.

6. The industrial robot according to any one of the preceding claims, wherein the industrial robotis covered by a double wall construction (20) comprising a watertight inner wall (22) and anouter wall (24) comprising micro pores (16), and said outer wall comprising said exterior surface(10) of the robot, wherein a space (26) is created betvveen the inner wall (22) and the outer wall(24), wherein the robot further comprises tubing (28) that is configured to transport an anti-bacterial liquid into said space (26), out through the micro pores (16) and onto the exteriorsurface (10), and that a pump device is provided for pumping the anti-bacterial liquid throughthe tubing (28), into said space (26) and out through the micro pores (16), thereby providing theliquid film.

7. A method for providing a self-cleaning and/or self-disinfecting exterior surface (10) on anindustrial robot (1), comprising providing a liquid film (12) on the exterior surface (10) of the robot.

8. The method according to claim 7, comprising providing the exterior surface (10) of the robotwith a pattern of micro pores (16) and pumping a liquid through the micro pores and onto the exterior surface. 7 16195SE Draft 2016-11-15

9. The method according to any one of claims 7-8, comprising providing the liquid film (12) bymeans of an anti-bacterial liquid.

10. The method according to any one of claims 7-9, wherein the liquid film (12) is obtained bymeans of a liquid comprising ozonated water.