A numerical model with nonuniform grids for the analysis of dynamic characteristics of scratched tilting-pad bearings

Abstract

Purpose The purpose of this study is to present a numerical model for scratched tilting-pad bearings (STPBs) with nonuniform grids. In addition, the model is used to reveal the effects of the structural parameters of bearings on the dynamic characteristics of STPBs under impact loading. Design/methodology/approach By combining the Reynolds equation, the flow balance equation and the assumption of adiabatic bearings and shafts, a thermo-hydrodynamic model with nonuniform grids of scratched journal bearings was built. Describing the motion of the shaft using the Euler method and introducing the pad-tilting-angle modification equation, a dynamic model of STPBs was established. Findings The occurrence of scratches in tilting-pad bearings yields great sensitivity to impact loading. Less width-to-diameter ratio and larger clearance ratio reduce the minimum film thickness and enlarge the maximum film pressure, which may lead to bearing collision or abrasion. Moreover, STPBs with larger clearance ratios take longer to recover from impact loading. Originality/value This work is original and a valuable reference for the analysis of the dynamic characteristics of STPBs. The effects of other factors on the dynamic characteristics of STPBs can be further investigated based on this model.