Patent ID: 8451557

Claim:
A disk drive device, comprising: a hub on which a recording disk is to be mounted; a base rotatably supporting the hub through a bearing unit, the base having, on a hub-side surface, a projecting portion that has a cylindrical side surface, the center of which being along the rotational axis of the hub; a laminated core formed by laminating steel plates, the laminated core having a ring portion and a plurality of teeth that extend radially from the ring portion; a tubular vibration-deadening ring, one side surface of which being press-fitted into the ring portion, and another side surface of which being fixed to the cylindrical side surface of the projecting portion; coils wound around the plurality of teeth; and a magnet fixed to the hub, the magnet being magnetized for driving with a plurality of poles along the circumferential direction and arranged to radially face the plurality of teeth, wherein the one side surface of the vibration-deadening ring is pressed against the ring portion, in a direction along the rotational axis of the hub, at least at a position closer to a surface of the laminated core facing the hub than to a surface of the laminated core facing the base, and wherein the laminated core is formed so that a width, in the radial direction, of the ring portion is smaller than a width, in the circumferential direction, of a portion of the plurality of teeth, the coil being wound around the portion.