No lubrication plastic bearings for earthmoving machines

Injection-moulded plain bearings have been developed for earthmoving machines for lubrication-free operation even while working at maximum load capacity performance.

Produced by global polymer specialist, igus, the new bearings are a stronger and more cost-effective alternative to steel bearings for the agricultural and construction machinery industry. Using its patented iglidur materials, the Q3E plain bearing, the company has for the first time managed to manufacture heavy-duty bearings made of two layers of high-performance plastic using a cost-effective injection-moulding process.

If an excavator moves hundreds of kilograms of sand, enormous loads act on the bucket’s bearing points. So far, igus has primarily used igutex-series plain bearings to handle this. The bearings are made of different materials and manufactured in a winding process. Integrated solid lubricants ensure low-friction dry operation. The outer layer provides enormous strength.

“We have now succeeded in implementing a multi-layer structure using the injection-moulding process, that is both stronger and more cost effective than alternatives,” says igus South Africa managing director, Ian Hewat. The result was the iglidur Q3E series. “The new technology enables us to mass-produce multi-component heavy-duty bearings using very cost-effective injection moulding.”

Igus bearing specialist, Juan-Eric Davidtz says The new iglidur Q3E series is the result of intensive cooperation between igus material development and the specialists from igus’ in-house tool making. While developing iglidur Q3E, our goal was to implement a multi-part structure similar to the igutex series with iglidur Q3 high-performance plastic for a tribologically optimised core and a strongly reinforced polymer for a mechanically high-strength shell.”

Heavy-duty applications normally require bearings made of metal or fibre composite bushings, for example in construction and agricultural machinery. To reduce costs, the plain bearings made of iglidur Q3E are used as their maximum dynamic surface pressure is 75MPa. This means that it can

cover many heavy-duty applications. The decisive advantage is that the plain bearings require no lubricating grease. Microscopic solid lubricants are integrated into the polymer of the inner layer and released gradually over the bearing’s service life.

“Construction and agricultural machinery maintenance are two areas where lubricating the bearing points is one of the most time-consuming tasks,” says Juan-Eric. “By switching to iglidur Q3E or igutex, users can reduce maintenance costs and extend machine service life. Neglecting lubrication for classic metal bearings is a frequent cause of expensive damage to shafts and plain bearings.”