Slewing ring bearing for food contact

It is a familiar issue: slewing ring bearings for rotating components, for example in a bottle filling plant, are rarely available on the market in hygienic, food-contact compliant designs. Classic bearing designs present bacteria with a lot of 'attack surface' and are usually not easy to clean thoroughly, sometimes requiring more development work for a hygienic cover, which means more time and costs.

“We wanted to offer a simpler solution and have therefore developed a hygienic version of our iglidur PRT slewing ring bearing,” says Rob Dumayne, drytech director at igus UK. “It is made of stainless steel and FDA-compliant wear resistant polymer and is designed in such a way that it can be cleaned without residue and, importantly, without having to be removed from the machine. This eliminates the need for additional protective covers.”

During the design and manufacture of the new bearing, igus engineers were guided by the European Hygienic Engineering and Design Group (EHEDG) guidelines – an association of research institutes, public health institutions, food processors and suppliers for food production. The goal is to offer bacteria as little attack surface as possible, employing several innovate design features. There are no 90˚ corners, welds and edges; all components of the slewing ring bearing are rounded. All levels have a gradient of at least three degrees, so that water runs off completely and does not collect. Wherever metal meets metal, FDA-compliant seals are installed, preventing dead spaces where screws connect.

“Thanks to these special design features, so-called clean-in-place cleaning is possible,” says Dumayne. “Full disassembly is not necessary for cleaning – users can simply rinse the bearing with detergents and thus reliably remove all residues.”

The hygienic design version of the PRT slewing ring bearing came from a market research study.

“The food and packaging industry is developing rapidly and more and more specialist machines are in demand,” says Dumayne. “In most cases manufacturers need special or customised components. We therefore offer them the opportunity to produce this new bearing in hygienic design to match their individual needs.”

Here, too, users benefit from the usual advantages of igus products: The stainless steel rings move on sliding elements made of iglidur, a high-performance plastic in which solid lubricants are integrated. These enable low-friction, dry running and protect the environment, with no need for oil or lubricant. The slewing rings are delivered ready for installation and, thanks to the self-lubricating effect, work maintenance-free for years.

www.igus.co.uk