Large induction motor anti-friction bearing selection

The majority of motor specifications utilize L/sub 10/ life as the sole selection criterion for anti-friction bearings. At times, L/sub 10/ lives in excess of 100,000 hours are specified in an attempt to prevent recurring field problems when the failures are originating from nonL/sub 10/ mechanisms. In some cases, these failures occur indirectly from overspecifying L/sub 10/ life. Some general examples of this occurence are described. A successful bearing design requires the consideration of many equally important factors, which are discussed in this article.