Maintenance-free, economical alternative to classic cast housing bearings

Nature can provide engineering with great inspiration; for instance, the shape of the new igubal pillow block bearings from Igus is based on the design of a tree. Flattened radii ensure maximum strength against mechanical stresses, like a tree’s base. Thanks to this bionic shape, these lubrication- and maintenance-free high-performance plastic housings are said to be a real alternative to classic cast housing bearings.

Whether used to deflect rollers for conveyor belts in a cement factory or in tilting mechanisms of trailers on the farm, Igus argues that cast housing bearings with metal ball bearings ultimately reach their limits in dusty, wet and dirty environments. Heavy contamination and a lack of lubrication are responsible for 80% of premature bearing failures in these applications. And there is a constant risk of corrosion to metal.

Igus says these are all strong reasons to replace the ball bearings with lubricant-free bearing inserts made of high-performance plastic. Its igubal polymer pillow block bearings, available in standard sizes of 20, 25 and 30mm, allow fast, one-to-one replacement. Also available are two- and four-hole flange stops in sizes 20, 30 and 40mm.

Igus engineers are pursuing two strategies to ensure that the plastic pillow block bearings are sufficiently robust in industrial applications. Firstly, they use fibres and fillers that strengthen the igubal plastic in such a way that it can withstand high surface pressures and edge loads even under continuous loads. Secondly, the design engineers are guided by a model from nature: the tree root connection, which can be found between the branches and trunk or where the tree trunk is firmly rooted in the ground. This design is seen as particularly efficient and robust. The designers have optimised the shape of the housing supports (collars) and removed the constant radii that distribute the forces more evenly, making the igubal housing bearings highly resilient.

Thanks to their chemical resistance, corrosion-free property and insensitivity to dirt, the bearing inserts made of the material tribopolymer iglidur J already achieve a much higher lifetime than legacy metallic bearings in numerous customer applications. In addition, having no lubricants reduces maintenance and cleaning effort, and improves environmental protection. There are no lubricants at any point in the system that could leak into the environment or the product.