DYNAMIC PRESSURE BEARING AND SPINDLE MOTOR WITH THE SAME, AND DISK DRIVING DEVICE USING THE SPINDLE MOTOR

摘要

PROBLEM TO BE SOLVED: To discharge bubbles collected between a thrust bearing part and a radial bearing part. SOLUTION: The thrust bearing part is provided with a pump-in type spiral groove as a dynamic pressure generating groove, and the radial bearing part is provided with a herringbone groove line, which is formed into an unbalance shape in the axial direction, as a dynamic pressure generating groove. Oil is continuously held between the thrust bearing part and the radial bearing part. At least one spiral groove of the spiral grooves provided in the thrust bearing part is formed to be extended inward in the radial direction in comparison with other spiral grooves. COPYRIGHT: (C)2004,JPO