| 摘要 |
PURPOSE:To generate such a pressure distribution state that prevents perfectly the intrusion of grease, dust, etc. into a magnetic disk device having a magnetic disk turning mechanism part, by forming an eccentric circular contour to the center of a rotating body for the form of a non-rotating part which encloses the body of the exposed side to the outer air. CONSTITUTION:A non-rotating part 5 containing a base plate, etc. forms a contour which is exposed outside a magnetic disk device to a rotor 4 which contains an attachment part, a shaft part, a rotor part or a pulley part, etc. of a magnetic disk 1. The center O' of the part 5 is set at a position where the eccentricity is generated by a distance l to the center O of the rotating body 4. An air path 6 linking the outer air and the inside of the magnetic disk device is provided at the longest area of the gap formed by the body 4 and the part 5 in the direction of the diameter. When the rotor 4 turns, a relation P1<P2 is produced for the pressure at the gap between the rotor 4 and the part 5. At the same time, the eccentric distance l or the path resistance generated by a change of the sectional area of the path 6 is set so as to satisfy a relation P3<P2 for the pressures P3 and P2 of the path 6 at the inside of the magnetic disk device. |
