DYNAMIC-PRESSURE BEARING MECHANISM, SPINDLE MOTOR, DISC DRIVING DEVICE AND METHOD OF MANUFACTURING DYNAMIC-PRESSURE BEARING MECHANISM

摘要

PROBLEM TO BE SOLVED: To provide various shapes of dynamic pressure generating groove and to improve abrasion resistance of a dynamic-pressure bearing mechanism.;SOLUTION: Laser beam is applied to a part as a hill portion 44b adjacent to the dynamic pressure generating groove 44a, of a sleeve 21 forming the dynamic pressure generating groove 44a. A part receiving irradiation, of the sleeve 21 partially receiving irradiation of laser beam is heated to a solution temperature or more to be partially dissolved. Then electrolytic processing is performed, thus the part (hill portion 44b) changed in its metal structure is hardly dissolved by electrolytic processing, and a part not changed in its metal structure, that is, not receiving the irradiation of laser beam is dissolved by electrolytic processing to form the dynamic pressure generating groove 44a at that part.;COPYRIGHT: (C)2007,JPO&INPIT