Theoretical analysis of surface roughness effect on hydrodynamic performance for bearings type 5220

Abstract

In this research, we studied the effect of surface roughness for bearings of inner ring and cylindrical rotor type 5220, on the hydrodynamic lubrication in performance convergence area by analyzing the effect of surface roughness on the oil film thickness around the bearing, then influence on generated pressure by rotating shaft. Matlab. R2013b program with finite differences method of five nodes grid used to solve Reynolds equation numerically. the results appear that when the roughness of bearing surfaces is 18.2 µm (high finishing surfaces bearings), this will be decreasing 49% from the oil film thickness between surfaces, which cause increasing total pressure from (65.74 M. Pas.) (in rough surfaces) to (748.3 M. Pas.) which enhancing the ability of bearing to rising load of rotor shaft in the limited speed reach to (18.78 K.N.).