저널 오정렬 및 수막두께의 축방향 단계변화의 복합영향을 고려한 수직펌프용 유체동압 저널베어링의 하중지지력 변화에 관한 연구 A Study on the Change of Load Carrying Capacity of a Hydrodynamic Journal Bearing for a Vertical Pump Considering Combined Influence of Misalignment of Journal and Axial Step Change of Film Thickness
pp.652-660
Load carrying capacity(LCC) can be reduced from its design value as a result of film thickness change when a journal is misaligned and some part of bearing is unintentionally translated. In this study, the numerical solution of the incompressible Reynolds equation was obtained by using the finite difference method and mass conservation algorithm (JFO boundary condition) with periodic pressure distribution in circumferential direction to analyze the change of LCC due to journal misalignment and step change of film thickness in axial direction for a journal bearing of vertical pumps. Smallest LCC in each eccentricity ratio is obtained as two angular positions are changed – an angular position where misalignment occurs, and another angular position where the axial step takes place while the degree of misalignment is fixed at 90%. Compared with the reaction force of plain journal bearing, the LCC reduced as much as 26.7% due to geometric effects of journal bearing at the eccentricity ratio of 0.9, while the step height is no higher than 0.1 times of bearing clearance.