Improved Rolling Element Bearing Thermal and Life Prediction with Validation

ABSTRACT: To provide improved life prediction estimates for rolling element bearings used in gas turbines and general rotating machinery, an update to the lubricant traction, heat generation, and life calculation methodology currently incorporated in a commercial-of-the-shelf (COTS) analysis program is proposed. Existing analysis tools are based on correlations and algorithms that have not been updated in more than two decades and are not capable of accurately predicting the life of bearings using new materials such as Pyrowear 675, M50 NiL, and ceramic rolling elements. In this Phase I project, updates to traction, heat generation, and fatigue life calculations in the COTS program SHABERTH are proposed. Starting from a comprehensive review of recent technical literature, new algorithms and characterizations will be incorporated into a single bearing version of SHABERTH. The updated code will be tested against both published bearing life data and proprietary information provided from a gas turbine company. Results from the comparisons will determine the best methods to improve life prediction accuracy. The Phase I project will also create a prototype graphical user interface for a modern, fully integrated, platform independent rolling element bearing analysis tool based on the fundamental SHABERTH methodology enhanced by the new life prediction techniques. BENEFIT: Essentially all detailed rolling element bearing analysis programs are based on work that is several decades old and targeted for use on mainframe computers. A modern, updated, and user friendly microcomputer based analysis tool that can accurately predict fatigue life would have widespread application in both military and commercial rotating machinery.