Thermal elastohydrodynamic lubrication analysis for tilted and skewed rollers in cylindrical roller bearings

Abstract

Due to the imperfect geometry and misalignment, cylindrical roller loading may result in both the roller tilting and skewing. Roller tilting coupled with skewing is important for the working lifetime of the bearings. To investigate the effect of the roller tilting and skewing on the thermal elastohydrodynamic lubrication, a model with non-Newtonian property of the lubricant has been built and a complete numerical solution has been obtained to address the relationship between the tilted and skewed roller effect and the thermal effect. Effects of the tilting angle, the rotating speed, and the applied load are discussed. In addition, profiles of the roller ends and generatrix are modified to reduce the roller tilting coupled with the skewing effect. Results show that, the thermal effect and the uneven distribution of the lubricating performance are the most prominent when both tilting and skewing effect are considered. Larger tilting angle, and heavier applied load causes greater maximum pressure and temperature, and thinner minimum film. Higher rotating speed leads to greater maximum film temperature, although thicker film. Profile modification of the roller’s ends and generatrix may reduce the effect of roller tilting and skewing. These findings provide important insights into the lubricating design in rolling bearings.