| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a dynamic pressure bearing arrangement aiming to reduce the wear during use time. <P>SOLUTION: Measure of an outer diameter d and an effective bearing span Y are defined so that a value P/(d×Y) which divides a receiving gross weight P wherein the gross weight of a rotating member including a disk to be mounted on a hub 11 is set as P [N], by a product (d×Y) of an outer diameter measures d [mm] of an axis section 2a and an effective bearing span Y [mm] of radial bearing sections R1 and R2 becomes≥0.02 and≤0.12. Here, the effective bearing span Y indicates a distance in an axial direction from a mid position in the axial direction (position in the circumference direction line X1) of an upper side smoothing section A5 to a mid position in the axial direction (position in the circumference direction line X2) of a lower side smoothing section B5. Also a sleeve section 8 which forms the radial bearing sections R1, R2 between an axis section 2a is formed with sintered metal, and this sleeve section 8 is formed with materials powder involving Fe powder≥60 wt.% and≤80 wt.%. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
