Schaeffler (UK) has developed a custom, three-ring bearing for a paint robot hand axis system, replacing two crossed roller bearings and three geared rings, resulting in a more compact, lightweight system that is maintenance-free and easier to mount. All 15 bearings for the hand axis system were supplied by the Schaeffler Group to Atlanta, developer of the hand axis system, who in turn was under contract to automotive paint company Dürr-AG (Painting Systems).
The hand axis system, which is located at the end of the robot arm, guides the paint atomiser system. Paint robot systems now have to be able to cope with increasingly complex geometries and surfaces that are often difficult to access, so Dürr-AG required a more compact, lighter hand axis system that would also be maintenance-free and easy to mount.
Schaeffler Group engineers therefore worked closely with Atlanta to develop a custom bearing solution. The resulting three-ring bearing comprises two, four-point contact bearing raceway systems with surface-hardened raceways, externally geared bearing rings and an intermediate ring. The rolling elements are guided in cage segments.
The new three-ring bearing replaced two crossed roller bearings and three geared rings that had to be screwed together. Rather than having to mount five separate components, there is now only one. Not only does this result in increased rigidity of the system, it also significantly reduces the design envelope.
In addition to the two, three-ring bearings, each axis incorporates deep groove ball bearings, four point contact bearings, axial angled needle roller bearings and axial needle roller and cage assemblies.