Contact Stress Study and FME Analysis of Large Size Thrust Ball Bearings

Thrust ball bearings with extremely large size and capacity, are not standardized and could not be found in catalogues. In aim to investigate possible failure causes of thrust ball bearings in heavy machinery excavators, this paper presents stress and deformations calculation supported with FME analysis in balls-raceway interfaces because of carrying whole upper construction and allow rotation movement. In this paper it was performed numerical calculations and their comparison for two, conceptually different types of large size thrust bearings. First one is classical pivot, such as load distribution in modified new bearing solution. Contact stress calculation of those bearings and FME analysis show that stress and deformation values for ball are near to the limit of static load capacity. Presented study supported by images of balls and raceways damage appearance, with or without grease as a lubricant, could be very useful in the bearing failure analysis.