A hygienically designed rotary bearing in the iglidur PRT series
enables cleaning without disassembly for hygiene-intensive industries

Hygienic design slewing ring bearings have typically been in short supply when
it comes to the food industry.. Manufacturers of machinery for
hygiene-sensitive areas have therefore often had to design additional
protection covers. But now igus is reshuffling the cards – with a hygienic-type
iglidur PRT slewing ring bearing that enables fast and residue-free cleaning.
Therefore these slewing ring bearings can remain permanently installed in an
application with food contact, avoiding the need to develop a separate cover.

Manufacturers of special machines
for hygienic areas in the food, medical and pharmaceutical industries are
familiar with the problem: 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.”

New design means easy
cleaning in the application

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-degree 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 Rob. “Full disassembly is not necessary for cleaning
– users can simply rinse the bearing with detergents and thus reliably remove
all residues.”

igus manufactures new slewing ring bearing on demand as a special component

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 Rob. “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.