| 摘要 |
PROBLEM TO BE SOLVED: To enhance reliability in the writing/reading of a magnetic disc by arranging a bearing at a part other than the radial extension of effective threaded part of a screw tightening hole made in the upper end face of a hub means and setting the inside diameter at the dust seal part of hub means shorter than the outside diameter of bearing thereby reducing the nonrepetitive deflection. SOLUTION: A bearing 6 is set through a bearing 5 and a spacer 17 and engaged with a hub means 8. A dust seal member 18 is secured to a fixed shaft 1A while abutting against the inner ring 6a of bearing 6 at the upper end thereof and the outside diameter thereof is located through a micro-gap (g) with respect to the hub means 8. When the bearing 6 is disposed while avoiding the radial direction of effective threaded part of a fixed threaded hole 8b made in a disc clamper 15, nonrepetitive deflection is not increased. Furthermore, when the outside diameter at the dust seal part of hub means 8 is set shorter than the outside diameter of bearing 6, rigidity of hub means is increased and stress in the bearing is substantially eliminated. |
