Patent ID: 8634160
Filing Date: 2014-01-21
Classification: F16C,G11B,H02K

Abstract:
1. A disk drive device comprising: a hub having an outer circumferential wall portion configured to hold a recording disk; a base member having a cylindrical portion, whose central axis is a rotation axis of the hub, on a surface on the side of the hub; a fluid dynamic bearing configured to hold a lubricant and rotatably support the hub relative to the base member; a stator core having a ring portion fixed on an outer circumferential surface of the cylindrical portion and a plurality of salient poles extending in the radial direction from the ring portion; and a magnet fixed to an inner circumferential surface of the outer circumferential wall portion, the magnet being arranged to radially face the plurality of salient poles and provided along the circumferential direction with a plurality of magnetized poles for driving, wherein the fluid dynamic bearing has a capillary seal portion for sealing the lubricant, an opening of the cylindrical portion is provided on the outside of the capillary seal portion in the radial direction, the hub has a cylindrical hanging portion that faces the opening in the radial direction and forms a narrow gap portion with the opening, a dimension of the narrow gap portion in the radial direction is at most 0.2 mm and a dimension of the narrow gap portion in the axial direction is at least five times the dimension of the narrow gap portion in the radial direction, and the base member is formed from aluminum sheet or steel sheet.