Robots have changed enormously since their first tentative steps into manufacturing. As the range of applications for these flexible tools has continued to expand, the design and configuration of robot arms continues to evolve to ensure that they are able to operate within the harshest environments, whilst still retaining the highest levels of reliability.
Today, robots are widely used in many different areas ranging from the highest class of cleanroom to extreme environments such as those found in foundries, welding, painting or adhesive dispensing applications. Sometimes it is necessary to expand the working envelope of a robot, and the most common solution is to mount the robot to a 7th axis linear track.
It goes without saying therefore, that these tracks must also be able to withstand the same rigours as the robot. In this article Güdel UK’s Will Bourn explains how the design characteristics of the company’s TrackMotion products enable them to withstand the most challenging operating conditions.
Güdel is dedicated to rack and pinon based linear motion, initially building gantry robots, but recently becoming more and more specialised in auxiliary linear motion for robots. The company’s TrackMotion linear axes range covers both floor mounted and overhead applications, and even extends to slides for the very largest new articulated robots with lifting capacities of up to 2.3 tonnes. With such a diverse range of products it goes without saying that in certain cases these tracks find themselves operating in particularly harsh environments.
As the linear track effectively becomes an integral part of the robot, operating as a 7th axis, it is essential that the linear track is able to match the performance and reliability of the robot irrespective of the environment within which it is operating. The design of Güdel’s TrackMotion range offers the highest levels of protection for the rolling elements when compared to the more traditional approach of a profiled guide-way.
It is essential that the linear track is able to match the performance and reliability of the robot, irrespective of the application
In a conventional linear bearing rail, the roller bearings move directly on the guide-way surface, and if these areas are left unprotected, dirt and debris can easily be pulled into the rollers causing premature failures to occur.
Güdel’s TrackMotion products all use cam follower bearings, which roll upon a flat, hardened tool-steel guide-way surface, so the actual bearing rollers are contained within the cam follower and are hence fully protected. Brass guideway scrapers mounted on the roller housing clean foreign materials from the guide-way surface as the robot carriage moves along. Even glued-on debris such as dried paint, weld spatter or adhesives are effectively removed in this way.
The rack itself is mounted on its side together with an overhead shield that prevents debris falling onto it. Also, as it is hardened it is resistant to mechanical damage from any debris that may get through.
Will Bourn explains: “By addressing the protection of the slide mechanism at the basic concept level, we very rarely have to consider extra shielding on our tracks. This saves cost and complexity, and also makes Güdel tracks much more durable and easier to access for any maintenance work.”
Güdel manufactures all of their own racks, guide rails, rollers and gearboxes which are all used not only across the range of robot tracks, but also in the company’s overhead gantry systems. This widespread use of a common component set means that the reliability and durability of the complete component set is assured, in whichever environment the slide is used. The capability to accommodate ATEX certification for potentially explosive atmospheres, and other changes which allow the tracks to be installed in a cold-room at minus 40° are also available.
These design principles are at the heart of the reasons why many of the world’s leading robot integrators turn to Güdel when they need to enhance the working range of their 6 axis robot systems.