Dusty environments can pose a challenge for overhead conveyors used in industry and logistics. When particles settle on conventional metal bearings, deposits can reduce smooth operation and, in severe cases, cause failure. To address this issue, igus has launched a new hybrid ball bearing from its xiros series.

Made from stainless steel and high-performance plastic, the bearing enables lubrication-free and dirt-resistant operation while supporting loads of up to 39 kg.

In industry and logistics, goods and workpieces need to be transported between production and storage areas quickly while using minimal space. Overhead conveyor technology is commonly used for this purpose.

“Design engineers are currently endeavouring to make these systems more efficient as users are increasingly less accepting of downtime and breakdowns. Even short interruptions can cause high costs and delays,” said Marcus Semsroth, Head of Business Unit xiros Polymer Ball Bearings at igus.

One way to improve efficiency is by replacing the ball bearings used by trolleys moving on aluminium profiles.

“For this purpose, we have launched a new hybrid ball bearing from the xiros series. It makes overhead conveyors more fail-safe and requires less maintenance,” Semsroth added.

In most overhead conveyors, carriages move on standard metal ball bearings. These are degreased and filled with low-friction oil to reduce friction. However, the low-viscosity oil can leak through the seals and attract particles, particularly in dusty environments such as the textile industry.

The resulting deposits can affect smooth operation and, in the worst case, lead to failures.

“To get to grips with this problem, we have designed the new hybrid ball bearings in such a way that they work without lubrication,” explained Semsroth.

The use of high-performance plastic xirodur B180 enables low-friction dry operation, reducing susceptibility to dirt and eliminating the need for maintenance. The outer race also runs with low friction on aluminium profiles. Steel bearings generally require an additional plastic outer and are therefore more complex and expensive.

“In the past, many design engineers of overhead conveyors expressed the wish to switch from steel ball bearings to plastic variants from igus. In many cases, however, this was not possible as the load capacity of solid plastic bearings is too low,” Semsroth said.

To address this limitation, the inner race, the most critical component of the hybrid bearing where the highest surface pressure occurs, is made of stainless steel. The load balls are also made of stainless steel, but from a different alloy.

The cage is made from iglidur J3, a high-performance polymer containing additives designed to improve strength and sliding properties. This combination enables the hybrid bearing to support loads of up to 39 kg.

“Although metal ball bearings with a load capacity of 80 to 100kg are stronger, the new hybrid ball bearing is suitable for a wide range of applications in industry and logistics, for example in furniture construction or packaging systems.”

The ball bearings are available in three variants with inner diameters of 8 mm, 10 mm and 12 mm. A version with a spherical outer race is also available to enable smooth operation in aluminium profiles.