DYNAMIC PRESSURE BEARING, SPINDLE MOTOR USING THE DYNAMIC PRESSURE BEARING, AND DISC DRIVE PROVIDED WITH THE SPINDLE MOTOR

摘要

PROBLEM TO BE SOLVED: To correspond to high-speed rotation, and to obtain excellent stability and bearing stiffness. SOLUTION: A shaft, a disc-shaped thrust plate extending outwardly in a radial direction from the outer peripheral surface of the shaft and a cylindrical sleeve opposite to the shaft and the thrust plate so as to relatively rotate, are provided. A radial air dynamic pressure bearing using air as an actuating fluid is structured between the outer peripheral surface of the shaft and the inner peripheral surface of the sleeve. A thrust oil dynamic pressure bearing using oil as an actuating fluid is structured between the flat surface of the thrust plate and the sleeve. Therefore, the thrust oil dynamic pressure bearing is made larger than the radial air dynamic pressure bearing in diameter. COPYRIGHT: (C)2004,JPO