A study of effects of tooth surface wear on time-varying mesh stiffness of external spur gear considering wear evolution process

Gear meshing surfaces are readily exposed to wear due to inadequate lubrication and long-time operation. Accumulative wear causes variations of gear tooth profile, resulting in variations of gear tooth's mesh stiffness and gear system's dynamic characteristics. This study presents an evaluation of influences of tooth surface wear (TSW) on stiffness of the gear mesh considering wear evolution process. Specifically, a wear prediction model for external spur gear (ESG) was established according to the Archard's wear equation. Considering the worn tooth profile, a modified analytical time-varying mesh stiffness (TVMS) model was derived by the potential energy method. The modified TVMS model was then applied for an ESG pair and the numerical results demonstrate that TSW may lead to significant reductions of mesh stiffness during the double tooth contact period. Furthermore, effects of TSW on TVMS were quantified and the results indicate that the mean decrease of mesh stiffness is almost proportional to the maximum tooth wear in the initial wear evolution process.