Fluid dynamic bearing system of spindle motor for driving e.g. compact disk (CD), has fluid dynamic bearings whose sealing gap is formed adjacent to bearing gap, so that ratio of axial length and gap width satisfies preset value

摘要

The system has a movable bearing component (12) that is rotatably mounted relative to a fixed bearing component (10) about an axis of rotation (16). A bearing gap (14) formed between the bearing surfaces of the fluid dynamic bearings (18,22,28,30), is filled with storage fluid. A sealing gap (36) for sealing an open end of the bearing gap, is formed adjacent to the bearing gap towards direction of the rotation axis, such that the ratio of axial length and the width of the sealing gap is less than 40. Independent claims are included for the following: (1) a spindle motor; and (2) a method for optimizing shock resistance of fluid dynamic bearing system.