Knowledge of the roller bearing temperature distributions can aid in the detection of several abnormal conditions before catastrophic failure occurs. Results from a study done for the AAR by the University of Illinois are helping railroad researchers to better understand the temperature distribution in roller bearings under normal and abnormal operating conditions. Finite element models were developed by the U of I for a Class-F tapered roller bearing to provide a method for predicting steady-state temperature distributions for normal and abnormal bearing conditions in order to understand bearing failure progression. For example, the model predicts that the heat generated due to jammed roller elements will raise the internal bearing temperatures past the thermal limits of the lubricant, and the critical area of the bearing may not be scanned by hot bearing detectors. One important motivation for doing thermal analyses of roller bearings under abnormal operating conditions is to determine the…