Study on the stiffness and fatigue life of tapered roller bearings with roller diameter error

Abstract

Geometric imperfection is a common problem in manufacturing of rolling element bearings. In particular, roller geometric errors frequently occur because a large number of rollers with relatively small size are engaged in a bearing. However, computational tools for rolling bearing characteristics take into account ideal bearings without any geometric error. In this study, the stiffness and fatigue life of tapered roller bearings were investigated with consideration for the effects of roller diameter errors possibly induced during manufacturing process. To this end, a general model for tapered roller bearings having rollers with diameter error (or defective rollers) was developed that can reflect the time-varying stiffness due to the roller error effects. The effects of the number of defective rollers, error magnitude, and position of defective rollers on the stiffness and fatigue life were investigated. Computational results showed that even small roller diameter errors appreciably alter the tapered roller bearings internal load distributions and therefore the stiffness and fatigue life of tapered roller bearings.