A Study on the Heat Generation and Cage Dynamics of Roller Bearings for Turbo Engines

The cylindrical roller bearings in a turbo engine can be exposed to skid damage due to insufficient radial load during high-speed rotation, potentially leading to bearing failure before reaching their fatigue life. However, determining skid conditions in the engine assembly is challenging because additional structures and sensors for cage speed measurement are difficult to attach. From a bearing temperature management perspective excessive slip of rollers and cages during skid conditions can lead to friction losses, an understanding of the relationship between bearing heat generation and cage dynamics is also needed. In this study, the dynamic behavior of cylindrical roller bearing was analyzed, and an approximate model for heat generation based on this analysis was established to unveil the trends in heat generation with respect to cage speed and slip ratio. The heat generation model was divided into structural contact friction losses and fluid resistance-related losses, with the former closely related to the cage slip ratio and the latter associated with cage rotation speed. Finally, the predictive performance of the proposed heat generation model in this study was validated by comparing it with the heat generated in roller bearing experimental data. The results of this study will enable the prediction of cage dynamics based on heat generation quantity and it will be useful in assessing the potential for skid damage.