Patent ID: 8482881
Filing Date: 2013-07-09
Classification: F16C,G11B,Y10T

Abstract:
1. A disk drive device comprising: a base; a top cover fixed to the base; a hub that rotates between the base and the top cover; a sleeve that rotates together with the hub; 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 hub 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 in such a way that the clearance becomes widespread toward an open end; a second capillary seal formed in a clearance between the second annular member and the sleeve in such a way that the clearance becomes widespread toward an open end; 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 hub in a fixed manner; an annular wall portion which protrudes toward the hub 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, the clearance between the second annular member and the sleeve being opened from the second flange side toward the first flange side.