Patent ID: 7764463
Filing Date: 2010-07-27
Classification: F16C,G11B,Y10T

Abstract:
1. A fluid dynamic bearing comprising: a shaft component; and a bearing sleeve component, said bearing sleeve component and said shaft component being rotatably supported with respect to each other; wherein at least one of said components is made of steel comprising by weight C: 0.6-1.20%; Si: 1.0% or less; Mn: 1.0% or less; Cr: 10.5-18.0%; Mo: 1.0% or less; S: 0.03% or less; and Fe, and wherein said at least one of said components further comprises a fluid dynamic bearing surface having a plurality of electrochemically machined hydrodynamic pressure generating grooves with raised substantially straight top ridge portions remaining between said grooves, wherein a profile view of said fluid dynamic bearing surface comprises substantially straight top ridge portions, a substantially straight sloped side portion, and a bottom portion.