Bi-directional misalignment effects on transient tribo-dynamics of offset-halves journal bearings subjected to step loading

This paper focuses on the nonlinear behaviors of offset-halves journal bearings (OHJBs), particularly under dynamic loading and journal misalignment. A new tribo-dynamic model is given to perform transient thermoelastohydrodynamic analysis in the crucial yet understudied domain of this novel structure. Bearing characteristics are compared among bi-directional misalignment, single-direction misalignment as well as alignment. The results demonstrate that the influence of bi-directional misalignment exerts dominance. Moreover, the evolution mechanisms of bi-directional misalignment and step loading on the time-varying stiffness and damping are evaluated. In addition, parametric analyses are done to emphasize key factors in the bearing design, including the horizontal offset and radial clearance, for better transient lubrication performance. This study enriches the structural optimum for dynamically loaded journal bearings.