Effect of roller profile on cylindrical roller bearing life prediction - Part II comparison of roller profiles

Four roller profiles used in cylindrical roller bearing design and manufact ure were analyzed using both a closed form solution and finite element anal ysis (FEA)for stress and life. The analyzed roller profiles were flat, end tapered, aerospace, and fully crowned and loaded against a flat raceway. Fo ur rolling-element bearing life models were chosen for this analysis: those of Weibull; Lundberg and Palmgren; loannides and Harris; and Zaretsky. The flat roller profile without edge loading has the longest predicted life. H owever, edge loading ran reduce life by as much as 98 percent. The end-tape red profile produced the highest lives, but not significantly higher than t hose produced by the aerospace profile. The fully crowned profile produced the lowest lives. Except for the flat roller profile, the predicted lives w ith the FEA method exceed those with the closed form solution. The fatigue limit proposed by loannides and Harris equates to one-half the value of a c ompressive residual stress that may exist in a rolling bearing steel.