| 摘要 |
<p>PURPOSE:To obtain a rotary cylinder provided with a mounting fact which does not damage the periphery of the central circle of a magnetic disk in a spindle mechanism and to obtain its inspection method. CONSTITUTION:A rotary cylinder 6 is formed of SUS 400-base stainless steel as a blank, it is constituted of an upper-part cylinder 6a provided with an inside diameter phid which is a little larger than the diameter of the central hole in a disk 1 and with a thickness (t) of about 1mm, and a ring mounting fact 6a at a prescribed angle of inclination deltatheta within a range of about 1 to 3 deg. so as to correspond to the inch size of the disk 1 is formed with high accuracy on its upper edge by a diamond polishing operation. A ring-shaped intersection line 1d in which the bottom face 1c of the disk is crossed with a chamfer 1b formed at the edge part of the central hole is brought into line contact with the ring mounting face 6b, the disk 1 is mounted and clamped by a clamp utensil. In an inspection method the ring mounting face 66 is irradiated with the parallel light, its reflected light is projected on a screen installed at a proper distance, and the diameter of a doughnut-shaped image is measured, and it is inspected whether the angle of inclination deltatheta of the ring mounting face is at a prescribed uniform value or not over the whole region of the circumference.</p> |
