Patent ID: 6556375
Filing Date: 2003-04-29
Classification: G11B

Abstract:
A hard disk drive comprising:a motor including: a rotor or hub having a downwardly depending flange at an outer periphery thereof, wherein said hub is journalled rotatably on a base by a bearing; said hub provided with a magnet positioned within an inner peripheral surface of the downwardly depending flange; a stator provided on the base so as to be opposed face to face with said magnet, and stator including coils; at least one magnetic disk having a standard outer diameter, said magnetic disk having a central aperture to be fitted around an outer peripheral surface of the flange provided around the hub of the motor, said magnetic disk adapted to be rotated by means of said motor, wherein said standard outer diameter is 2.5 inches (65 mm) and an inner diameter of the central aperture of a central aperture of a standard magnetic disk is 20 mm; and a disk restraining plate clamping said at least one magnetic disk to said hub; said disk restraining plate threadedly secured to said hub at a position over said magnet; wherein the inner diameter of said central aperture of said magnetic disk is larger than 20 mm which is the inner diameter of the central aperture of the standard magnetic disk standardized based on said standard outer diameter, and the outer diameter of the downwardly depending flange of said hub of the motor is enlarged to accommodate the larger inner diameter of said central aperture of said magnetic disk fitted thereon; said outer diameter of the downwardly depending flange of said hub being substantially identical with the larger inner diameter of said central aperture of said magnetic disk.