Fluid film lubricated dynamic bearings are commonly used for high speed revolutionary equipments acting as rotating shaft support element. Among these equipments which use the bearings as support elements, office automation equipment and IT related devices are widely use the applied. Optimization of bearing parameters is effective to improve the performance of the fluid film lubricated dynamic bearings since low noise and impact-proof characteristics are essential requirements for these equipments. On the other hand, bearings for miniaturized spindles are generally made by a mass production process which will eventually requires reduction of production costs. In this paper, 2.5 inch HDD spindle motor using fluid film lubricated dynamic bearings is used ; sensitivity analysis that considered manufacturing error was conducted for optimum design. As a result, the influence of bearing characteristic values upon the occurrence of manufacturing error was clarified.
