| 摘要 |
PURPOSE:To provide a disk rotating device capable of polishing the whole of both surfaces of a disk such as a magnetic disk and stably rotating the disk without generating side-runout. CONSTITUTION:A split chuck 14 is connected to the tip of a rotary shaft 4, and this split chuck 14 is divided into six sector chuck segments 15 whose center angle is sixty degrees with a slit formed form the disk section 14a to the middle of a cylindrical section 14b, and each abutting section of each chuck segment 15 comprises abutting faces 15a and 15a and a bottom face 15b. The abutting faces 15a and 15a are formed so as to make angle theta accurately correspond with the taper angle theta of a chamfer C. When the chuck segments 15 are opened, these abutting faces 15a and 15a abut on the chamfer C of a disk D, and the bottom face 15b is made to keep a state of non-contact with the disk D. Therefore, in rotating, the chuck 14 can hold and fix the disk D so as not to move in the thickness direction of the disk D. |
