Patent ID: 7625122
Filing Date: 2009-12-01
Classification: F16C

Abstract:
1. A fluid dynamic bearing assembly comprising: a bearing member axially defining an inner bearing hole therein extending along an axial direction of the bearing member; a spindle shaft rotatably received in the bearing hole with a bearing clearance formed between an inner periphery of the bearing member and an outer periphery of the spindle shaft; lubricant filled in the bearing clearance; at least one of the inner periphery and the outer periphery forming a bearing surface with channels formed therein; wherein the bearing surface comprises first and second groove regions, and the channels comprises first and second sets of channels alternatingly arranged along a circumferential direction of the first region, and third and fourth sets of channels alternatingly arranged along a circumferential direction of the second region, the channels of each set being parallel to each other while inclined to an axis of the fluid dynamic bearing in an unfurled view of the bearing surface, the first and second sets of channels deviating from the axis of the fluid dynamic bearing with different angles, and the third and fourth sets of channels deviating from the axis of the fluid dynamic bearing with different angles, a length of each first channel being larger than that of each second channel, and a length of each third channel being larger than that of each fourth channel, the channels forming a plurality of outer communication ends at opposite sides of the bearing surface in the axial direction of the bearing member.