Axial Load Effect on Contact Fatigue Life of Cylindrical Roller Bearings

Abstract

Besides primarily carrying radial load, cylindrical roller bearings with flanges or lips on both inner and outer raceways need also carry axial load in some applications. Because of the axial load, the equivalent dynamic load of the bearing will be increased and the bearing contact fatigue life will be decreased accordingly. The axial load effect on the roller bearing fatigue life had been studied by researchers in the past. Because of different assumptions used in their models, quite different predictions were made in their analysis. This work combines the methods used in the Fernlund-Synek and Brandlein models and studies general contact conditions such as partial contact along the roller length, partial loading zone of the bearing race, manufacturing tolerance and running-in effects on roller length, etc. New formulas for equivalent dynamic loads of the rotating and stationary races are derived. A fatigue limit load is also included in the life calculation to reflect the latest development in contact fatigue life analysis.