Concurrent impact of chipping and pitting damages in a locomotive power transmission system.

The reliability of power transmission systems in locomotives directly impacts trains' availability and running safety. The failure of gears, like pitting and chipping on teeth, is a common failure that can affect vehicle dynamics and reduce the system's safety and reliability. Based on the frequent visual inspections, the simultaneous occurrence of pitting and chipping on gear teeth are observed. It is the purpose of this research to investigate these defects and their possible coincidence. The dynamic response of the gear system to the presence of the pitting and chipping damages on one tooth, individually and concurrently, is theoretically and experimentally evaluated and compared. The dynamic interaction between the gear system and other elements, such as the traction motor and wheelset, is based on the operational conditions. The time-variant mesh stiffness is considered the primary internal excitation in the dynamics of the gear system. An analytical method based on the potential energy is used. The defects' coincidence effect on the dynamic response in time and frequency domains is studied. To measure the severity of the defects, some statistical parameters for different failure cases are calculated and compared. As a result, the parameters that exhibit the most sensitivity to the corresponding failure are introduced. [ABSTRACT FROM AUTHOR]