Spindle motor unit having hydrodynamic bearing

摘要

A spindle motor unit having a hydrodynamic bearing that retains a necessary amount of lubricant in the thrust bearing even when rotating and stopping operations are frequently repeated, and ensures reliability of the bearing, and allows correct recording and reproducing operations is obtained by reducing the clearance formed between the inner diameter surfaces 11d and 11e of base 11 and the outer diameter surface of flange 13.