DYNAMIC PRESSURE BEARING DEVICE AND MOTOR EQUIPPED WITH THE DEVICE, AND DISK DEVICE USING THE MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a dynamic pressure bearing device which hardly generates chipping of a nitrided layer formed by nitriding treatment and prevents the occurrence of burning and the deterioration over a long term, a motor equipped with the device, and a disk device using the motor. SOLUTION: In a dynamic pressure bearing device equipped with a shaft member and sleeve member relatively rotating, the shaft member is made of austenitic stainless steel. The outer peripheral surface has a nitrided layer. The nitride in the nitrided layer consists predominantly of chromium. COPYRIGHT: (C)2007,JPO&INPIT