The Importance of Vehicle Gear Tooth Meshing Stiffness in Gear Tooth Damage Quantification

The early detection of incipient failure in a mechanical system is of great practical importance as it permits scheduled inspections without costly shutdowns and indicates the urgency and locations for repair before a system incurs catastrophic failure. However, in this work a new technique for processing vibration data to quantify the level of damage, cracks only, in a gear system. The technique consists of a nonlinear numerical optimization. The optimization uses a dynamic model of the gear mesh used in vehicle gearbox and forms an estimate of both time-varying and frequency-varying mesh stiffness that best corresponds to the given set of vibration data. The procedure developed in this study can be applied as a part of either an onboard machine health monitoring system or a health diagnostic system used in the regular maintenance. As the developed methodology is based on the analysis of gearbox vibration under normal operating conditions, no shutdown or special modification of operating parameters is required during the diagnosis process. The process of quantifying the damage of gear teeth requires a set of measured vibration data and a model of the gear mesh dynamics. The results demonstrate the utility of the procedure as a part of an overall health monitoring system.