Disk drive device with improved centering holding function

1. A disc drive device having a plastic turntable mounted on a shaft of a spindle motor, wherein this turntable has a disc hole engagement projection provided with a ring-shaped projection and a plurality of centering portions which extend from this ring-shaped projection outwardly in a diametrical direction and have guide surfaces from which an edge of a disc hole easily slides off, a disc carrying portion formed connected to an outer circumference side of this disc hole engagement projection and receiving one surface of the disc, through holes formed defined between adjoining centering portions, and flexible cantilever beams extending in the through holes from the ring-shaped projection outward in the diametrical direction and having front end portions resiliently contacting a hole wall of the disc hole, two or more flexible cantilever beams being arranged in each through hole.

2. A disc drive device as set forth in claim 1 , wherein a ring-shaped back yoke and a ring-shaped chucking magnet are fit in a ring-shaped recess formed inside the ring-shaped projection; on a bottom surface of the ring-shaped recess, a plurality of plug projections rise up; these plug projections are fitted in stepped stopper holes formed in a ring-shaped plate of the ring-shaped back yoke whereby the front end portions of the plug projections increase in diameters in the step portions of the stepped stopper holes.

3. A disc drive device as set forth in claim 1 , wherein the two or more flexible cantilever beams being arranged in each through hole are spaced apart from each other.