Study of orifice compensated hole-entry hybrid journal bearing considering surface roughness and flexibility effects

The present work describes a theoretical study to demonstrate the combined influence of surface roughness and bearing flexibility on the performance of an orifice compensated hole-entry hybrid journal bearing system. The average Reynold equation governing the flow of lubricant in the clearance space between rough journal and bearing surfaces and 3-dimensional elasticity equation governing the displacement field in the bearing shell have been solved simultaneously using finite element method. The influence of transverse, isotropic and longitudinal roughness patterns on the performance of orifice compensated hole-entry journal bearing configuration have been studied for the various values of surface roughness parameter (Λ), surface pattern parameter (γ) and bearing shell deformation coefficient ( D ¯ c ) . The study indicate that the reduction in the bearing characteristic parameters such as load carrying capacity, fluid-film stiffness and damping coefficients due to the bearing shell flexibility effect can be partially compensated in roughened hole-entry flexible journal bearing system by making a proper selection of roughness patterns. The results presented in the study demonstrates that for an accurate prediction of bearing characteristic data, the consideration of combined influence of surface roughness and bearing flexibility effects in the analysis may be more appropriate to use.