Influences of tooth spalling or local breakage on time-varying mesh stiffness of helical gears

Time-varying mesh stiffness (TVMS) provides important information about the health condition of geared systems. Tooth faults, like crack, pitting, spalling and breakage, will change the TVMS. This work aims to reveal the influences of tooth spalling and local breakage on the TVMS of helical gears. Firstly, an analytical model is developed to incorporate the faults by combining slicing method, discrete integral method and potential energy method. Then, parametric study is conducted. Finally, conclusions are arrived and the results indicate that length, width and location of these defects are very important parameters that need to be considered for calculating TVMS of helical gears. This study provides a theoretical basis for fault diagnosis of helical geared transmissions.