Root Cause Failure Analysis of Outer Ring Fracture of Four-Row Cylindrical Roller Bearing

摘要

Four-row cylindrical roller bearings having pin-type steel cage and pronged machined solid brass cage are commonly used in the back-up roll assembly of cold rolling mills. The present article briefs about these bearings and investigates the root cause failure of such gigantic (inner ring ID = 865 mm, inner ring OD = 945 mm; outer ring ID = 1073.0 mm, outer ring OD = 1180 mm) four-row cylindrical roller bearings. In the present study, a visual examination of failed rolling surfaces has been emphasized. An analytical approach has been utilized to determine the maximum load on the roller and the outer ring raceway interface. The maximum principal normal and shear stresses have been evaluated for coefficients of friction equal to 0.001, 0.1, 0.2, and 0.3. A three-dimensional static finite element analysis has been performed to explain the cracking of the outer ring of the bearing. Condition monitoring based on oil analysis is adopted to validate the conclusions drawn from the finite element analysis of roller bearings.