SHAFT MEMBER FOR FLUID BEARING DEVICE AND METHOD OF PRODUCING THE SAME

摘要

A shaft member for a dynamic pressure bearing device is provided at low cost, where, in the bearing device, pressure balance in thrust bearing gaps formed on both sides in the axial direction of a flange section is retrieved in early stage. Both forming of a shaft blank (10) that integrally has a shaft section (11) and a flange section (12) and forming of a through-hole (19) in the flange section (12) of the shaft blank (10) so as to open at both end surfaces (12a, 12b) of the flange section (12) are performed in a common forging process. As a result, a through-hole (29) is formed, avoiding the bearing gaps (W1, W2) provided in both end surfaces of the flange section (22) of a shaft member (2) as a finished produce, so as to open more on the inner diameter side than the bearing gaps (W1, W2).