Thermal and viscoelastic coupled influences analysis on mixed lubrication in dynamic journal bearings

Abstract

The interaction of temperature variations and viscoelastic deformation is critical in dynamically loaded journal bearings, especially under fluctuating heavy load conditions. Previous studies have not fully explored the coupling of these two factors. Addressing this gap, this research introduces a novel transient mixed lubrication model that simultaneously considers thermal and viscoelastic effects. This model reveals intricate dynamics influencing the lubrication performance of journal bearings. The findings show that the combined impact of thermal and viscoelastic factors significantly alters the amplitude and phase of lubrication performance parameters. Notably, thermal effects tend to decrease oil film pressure while increasing asperity contact pressure, whereas viscoelastic effects enhance the oil film pressure peak and adjust its phase, concurrently reducing asperity contact pressure. Moreover, varying the eccentric speed profoundly influences the interplay between bearing thermal and viscoelastic effects. This study contributes to a deeper understanding of mixed lubrication in journal bearings and provides technical support for more accurate and predictive reliability improvement in complex mechanical systems.