| 摘要 |
PURPOSE: To eliminate the probability that lubricant on a rotary shaft is stuck to a disk and to miniaturize a motor without lowering the magnetic performance of the motor by fitting the disk to an axial part of a spindle hub to which the rotary shaft is fixed. CONSTITUTION: A member fitting to the central hole 1a of the disk 1 is not the rotary shaft 3, but is the axial part 8b of the spindle hub 8 fixed to the rotary shaft 3. Thus, although the internal diameter of the central hole 1a of the disk 1 is controlled by a standard, the axial part 8b may be designed so as to match with the standard, and since a fitting relation between the rotary shaft 3 and the central hole 1a is eliminated, the outside diameter of the rotary shaft 3 can be designed freely. Thus, when the outside diameter of the rotary shaft 3 is reduced than conventional one, when the outside diameter of the axial part 8b to which the central hole 1a of the disk 1 the spindle hub 8 is fitted is assumed to be B, and the outside diameter of the rotary shaft A, it is made A<B. |
