In an engineering milestone that is expected to offer significant cost savings to mining companies throughout the world, Schaeffler has developed the world's first sealed 241/1250 spherical roller bearing. Featuring an outside diameter of nearly two meters, the ultra-large 241/1250 bearing was specifically designed for the highest-capacity High Pressure Grinding Roll Crushers (HPGRs) used by the mining industry. Previously only available in an open configuration (i.e., without seals), Schaeffler's new sealed version of this massive roll support bearing is designed to prevent the crushing materials from contaminating its internal components.
Schaeffler developed the sealed 241/1250 bearing to help the mining industry cut costs and boost efficiency. Until now, miners have typically been forced to inject high quantities of grease into the bearings to prevent contamination. While necessary, this practice wastes resources and significantly increases a mine's preventive maintenance expenditures. By introducing a sealed bearing for this challenging application, Schaeffler's innovation promises to also increase mining productivity.
The bearing's sheer mass – as evidenced by a total weight of approximately eight metric tons, including rolling elements that weigh 60 kg each – presented an engineering challenge that very few companies are able to master, even before the complex sealing arrangement is factored in. The outside diameter of the molded seal, which features unique design elements that were first developed for marine applications, measures approximately 1.4 meters.
The state-of-the-art sealing properties are provided by metal shields installed on both of the bearing's side faces, each of which features an optimized polymer seal that prevents the ingress of crushing material. According to Schaeffler Industry Manager for Raw Materials Mike White, "The new sealed version of our high performance 241/1250 bearing is expected to offer significantly longer operating life, while substantially reducing the cost of preventative maintenance to the end user. Schaeffler is committed to helping our mining partners produce more while consuming fewer resources. We are very proud to be the first bearing manufacturer to offer this design improvement to the mining industry."
The new sealed 241/1250 spherical roller bearing, which is being produced at Schaeffler's manufacturing plant in Brasov, Romania, is expected to be commissioned into service in early 2017.