Dynamic pressure bearing apparatus for hard disk drive and polygonal mirror drive such as for photocopiers or laser printers

摘要

The bearing apparatus has a shaft or axle (2). It has a second component (3) with an insert opening (3a) through which the shaft extends. A bearing gap (G) of predetermined size is formed between an inner surface of the opening and an outer circumference of the shaft. The gap is filled with a fluid and allows rotation of the shaft relative to the second component. In either or both of the inner surface of the opening and the outer circumference of the shaft are distributed small pits and bumps, so that the surface is not smooth. The average roughness is between 0.1 and 1 micrometers. The shaft and the second component rotate relative to each other such that a radial dynamic pressure is generated in the bearing gap around the shaft. Independent claims also cover drives incorporating such a bearing and a method of manufacture.