New type motor for tough hard disk drive

A new type fluid dynamic bearing spindle motor has been developed for use in a small hard disk drive for mobile applications. Classified as an untied type motor in its basic construction, the new motor is constructed so that it prevents oil leakage and enhances the rigidity of the hard disk drive chassis. The characteristic structural feature of the motor is a hollow rotary spindle through which a stationary shaft is installed. The stationary shaft does not interfere with spindle rotation. Since the stationary shaft is secured between the top cover and base chassis, the motor enhances hard disk drive chassis rigidity, which is an advantage that cannot be achieved by the conventional untied type motor. Although measuring small and thin, the motor has excellent rotational accuracy and shock resistance.