Lubrication failure cycle prediction of WK-35 electric shovel rotary gear considering structure-force-lubrication factors

Abstract

To predict the failure time of WK-35 electric shovel rotary gear under dry running conditions, a multi-dimensional coupling prediction method based on elastic flow lubrication-gear tooth meshing-gear system heat transfer was proposed. The friction coefficient of the tooth surface was calculated by establishing the steady-state thermoelastic flow lubrication model of the rotary gear. The oil film retention parameters were introduced to form a time-varying friction coefficient calculation method, combined with computational fluid dynamics (CFD) to simulate the steady-state temperature distribution of gear teeth and the transient temperature distribution of the gear system. Through multi-dimensional parameter transfer and coupling, the dry running time of the rotary gear is predicted. The results show that the time scale of the model is from O(10⁻⁶) s in the elastic lubrication dimension of the tooth surface to O(10⁴⁾ s in the heat transfer dimension of the gear system, and the spatial scale is from O(10⁻⁶) m to O(10¹) m, and the failure of the rotary gear is predicted to be about 2 hours under dry running conditions by coupling the structure-force-lubrication-thermal characteristics.