Fluid-dynamic bearing system for rotary bearing of spindle motor used in hard disk drive assembly, has bushings surrounding divided sections of tubular case surrounding rotary shaft, forming gap which is filled with bearing fluid

摘要

The system includes a shaft (2) that is surrounded by a tubular case (4), and that rotates around a rotation axis (3). A flange (9) is formed at the outer circumference of the case to divide the case into upper and lower sections (4a,4b). The upper and lower sections of the case are surrounded by upper and lower bushings (10,11). The inner diameter of the bushings and the outer diameter of the case sections formed an outer bearing gap (12) which is filled with bearing fluid and which is connected to an inner bearing gap (5). A covering (7) is arranged facing the pressure plate (6) which is arranged at the outer circumference of the tubular case. The internal bearing gap is formed between the surfaces of the shaft, case, pressure plate and covering. Radial bearing areas (13,14) and axial bearing areas (19,20) are arranged with the case, pressure plate and covering.