F Niksai - PhD student, School of Railways Engineering, Iran University of Science and Technology,
M.A Rezvani - Associate Professor, School of Railways Engineering, Iran University of Science and Technology

The power transmission system is a key component of the locomotive to deliver power between the engine and the wheelset so that the dynamic performance of this system can have a direct impact on the performance of the locomotive. Therefore, a proper understanding of the dynamic behavior of these systems is necessary. In order to modelthese systems dynamically, the time-variant mesh stiffness is considered as the main internal excitation in the gear dynamics, which changes with the growth of tooth failuresuch as pitting. So the dynamic properties of the power transmission system are changed. In this study, the gear mesh stiffness in power transmission systems of the locomotive is calculated and the relationship between the pitting severity and the mesh stiffness is investigated. For this purpose, the potential energy method as an analytical method based on the dynamics of gear engagement has been used. Given the complexity of geometry in the gears, the formulas required to analyze this phenomenon are analyzed analytically. A MATLAB code has been developed for calculating the time-variant mesh stiffness.

Time variant mesh stiffness, Tooth pitting failure, Modeling, Locomotive power transmission