Patent ID: 8427777
Filing Date: 2013-04-23
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 the 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 the outer circumferential surface of the cylindrical portion and a plurality of salient poles extending in the radial direction from the ring portion; a coil wound around the plurality of salient poles; a magnet fixed to the 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; and a ring-shaped attraction plate fixed to the base member, the attraction plate being arranged to face the magnet in the axial direction, and including a magnetic material, wherein a first narrow gap portion is formed between the attraction plate and the magnet, a second narrow gap portion is formed between the base member and the end surface of the outer circumferential wall portion on the side of the base member, and the outer circumferential wall portion is configured to surround the attraction plate such that the range of the outer circumferential wall portion in the axial direction overlaps with the range of the attraction plate in the axial direction.