PERFORMANCE OF SLOT-ENTRY HYBRID JOURNAL BEARING CONSIDERING THERMAL EFFECTS

Abstract

With the worldwide tendency towards limit design, the assumptions of isothermal or (adiabatic temperature), conditions are becoming increasing unacceptable for bearing design. High bearing temperature is undesirable for two reasons, i.e. The location of maximum temperature and maximum pressure almost coincides possibly leading to combined Mechanical and Thermal failure of the journal bearing. The viscosity of the mineral oil is temperature dependent, and even a modest increase in lubricant temperature will lead to significant decrease in viscosity and most importantly in fluid film thickness. A scan of literature related to recessed and non-recessed journal bearing reveals that in most of the studies thermal effects have not been included in the analysis. Thermal consideration in the analysis of slot-Entry I lybrid Journal Bearing is expected alters the bearing performance characteristics. As there in no exact expression for the. viscosity in terms of both the temperature and pressure, because of continuing heat transfer from the bearing and increase in fluid temperature, will change the viscosity. Therefore, it is difficult to solve the governing, Reynolds equation with modified viscosity and input flow to the bearing as a constraint, together with the energy and conduction equations, also with the irregular boundary conditions. A Finite Element Method has been used to solve the simultaneous solution of the above-mentioned equations. The computed results indicate that inclusion of thermal effects in the analysis change the bearing performance characteristics significantly