Plastic spherical bearings used for student challenge on miniature railway

A team of undergraduate mechanical and electrical engineers from the University of Huddersfield competed in the Institution of Mechanical Engineers’ Railway Challenge, at the Stapleford Miniature Railway, near Melton Mowbray, Leicestershire.

Up against teams of students, apprentices and graduates from other UK universities and industry, the HudRail team had to design and build a miniature (10¼” gauge) railway locomotive. The train then had to compete in a number of track-based and presentation challenges including: energy storage; traction; ride comfort; noise; maintainability; and energy efficiency.

Thanks to the igus Young Engineers Support (YES) programme, which includes access to free product donations for students involved in design competitions and projects, the HudRail team was able to source one of the fundamental components for its entry – bearings.

“The Igus plastic spherical bearings used on the locomotive’s traction rod were of great help, providing us with specific advantages that would not have been possible to match with conventional metal-based bearings,” explains Ryan Robinson from the HudRail team.

The use of pivoting bearings is often associated with heavyweight materials, difficult installation and high costs. Most will require regular maintenance and are not usually corrosion resistant. Roller or plain bearings can malfunction prematurely due to high edge loads, or because they need to be readjusted, reamed or refitted in order to compensate for alignment errors.

Igus spherical bearings are not affected by these issues: made of the innovative Iglidur material they are easy to fit, cost-effective, lightweight and robust. They can be used in harsh environments, because the tribopolymer material is self-lubricating. The bearings also come with self-aligning features that offer many design advantages and help simplify assembly.

“One of the key benefits that stood out for us was that the igus bearings were resistant to dirt, dust and corrosion,” says Ryan Robinson. “Another advantage was that they were particularly good at vibration damping. Our locomotive was the most powerful one at the competition, but with that power also came the issue of vibration. After researching the market for bearings that could withstand this level of vibration, we determined the igus spherical bearings to have superior vibration damping properties.”

These qualities are of particular value on the underside of the locomotive. The working environment of a train is often a harsh one; finding a bearing capable of withstanding a constant bombardment of dirt and dust is essential and contributed to the success of the locomotive.