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

Abstract

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.

KEY WORDS:

• Rolling Mill Bearing
• Analytical Approach for Analysis of Rolling Element Bearings
• Finite Element Analysis of Roller Bearing
• Outer Ring Fracture

ACKNOWLEDGMENTS

The author is grateful to Profs. Deshpande and Bose (Dept. of Mech. Eng., IIT Bombay) for providing insight in the operation of the rolling mills and fatigue fracture, to Mr. Mukesh Gupta (Castrol India Ltd) for helping in the oil analysis, and to Mr. Bhatia, Mr. Khan, and Mr. Nair (Jindal Iron and Steel) for providing related data and drawings.

Review led by Bob Errichello