Patent ID: 8564908
Filing Date: 2013-10-22
Classification: F16C,G11B,Y10T

Abstract:
1. A disk drive device comprising: a base; a top cover fixed to the base; a rotator that rotates between the base and the top cover; a sleeve which has a plated surface and which rotates together with the rotator; a shaft assembly comprising a shaft retained in the sleeve in a freely rotatable manner relative to the sleeve, a first flange fixed to the shaft at a location facing with a first end surface of the sleeve with a clearance, and a second flange including an opposed surface facing with a second end surface of the sleeve with a clearance, one end of the shaft assembly being fixed to the base, and another end of the shaft assembly being provided to the top cover in a fixed manner; a first annular member which rotates together with the rotator and which surrounds an outer circumferential surface of the first flange; a second annular member which is provided to the second flange in a fixed manner and which surrounds at least a part of an outer circumferential surface of the sleeve; a radial dynamic pressure groove that is provided in at least one of an outer circumferential surface of the shaft and an inner circumferential surface of the sleeve; a thrust dynamic pressure groove that is provided in at least one of a surface of the first flange facing with the sleeve, the first end surface of the sleeve, a surface of the second flange facing with the sleeve, and the second end surface of the sleeve; a first capillary seal formed in a clearance between the first flange and the first annular member; a second capillary seal formed in a clearance between the second annular member and the sleeve; a lubricant filled in the radial dynamic pressure groove and the thrust dynamic pressure groove between the first capillary seal and the second capillary seal; a magnet provided to the rotator; an annular wall portion which protrudes toward the rotator in an axial direction and which is provided on the base separately from the second annular member; and a stator core which is fixed to an outer circumferential surface of the annular wall portion and which faces with the magnet in a radial direction.