Herfat A.

Emerson-Copeland Corporation, 1675 West Campbell Road, Sidney, OH 45365, USA, and Adj Professor, University of Cincinnati, OH Phone: (937) 493-2898, Fax: (937) 493-2366 USA, atherfat@copeland-corp.comRe: T08Hydrodynamic interaction between a rotating shaft (journal) and its associated bearing is an indication of the load capability assessment of this system. Shaft deflection and roughness of the bearing surfaces are the significant causes in limiting the load capacities of journal bearings. The shaft deflection limits the load capacity of full journal bearings to magnitudes less than the value estimated by hydrodynamic theory. The higher the load on the shaft, the larger the journal misalignment resulted from shaft deformation, and the more obvious effect on lubrication performance of journal bearing. Structural dynamic analysis of machine or system presents the mode shapes, including the constraint modes and frequencies of the components as well as the natural frequencies and mode shapes of the complete machine or system. The flexible shaft mode shapes predict the possibilities of the edge loading or direct contact between journal-bearing and shaft. The objectives for this analysis presented in this paper are: 1) To estimate the stress generated on the bearing housing and transferred to machine casing or shell due to unbalance excitation on the rotor and/or bearing-housing misalignments during manufacturing. 2) The load capacity of the bearing with flexible shaft can be predicted to a rational order of magnitude. 3) The analysis results also show obvious changes at distribution and value of oil film pressure, oil film thickness and oil temperature of journal bearing due to journal misalignment.