Patent ID: 7059772
Filing Date: 2006-06-13
Classification: F16C,G11B

Abstract:
1. A hydrodynamic bearing in a spindle motor having a rotation axis, comprising: a shaft; a sleeve relatively rotated with respect to said shaft; a bearing portion including a micro gap formed between said shaft and said sleeve, a lubricating oil retained as a working fluid in said micro gap, and a dynamic pressure generating groove formed on at least one side of an outer peripheral surface of said shaft and an inner peripheral surface of said sleeve in said micro gap, for generating a dynamic pressure so as to support a rotation of said shaft or said sleeve; a capillary seal portion adjoining said bearing portion, the capillary seal portion comprising: a first capillary seal portion adjoining said bearing portion, and having a first radial gap between an outer surface of said shaft and an first inner peripheral surface of said sleeve, said first radial gap at least widening the further along said rotation axis the radial dimension of said gap is from said bearing portion; and a second capillary seal portion adjoining said first capillary seal portion, and having a second radial gap between an outer surface of said shaft and an second inner peripheral surface of said sleeve, said second radial gap at least widening the further along said rotation axis the radial dimension of said gap is from said bearing portion; wherein