Disk drive device and method of press-fitting with reduced hub deformation

摘要

In the brushless motor, a hub has a cylindrical separating wall in between a yoke and two magnetic recording disks. The yoke is affixed to the inner surface of the separating wall of the hub using both a press-fit and adhesion. A first convex portion and a second convex portion are formed on the inner surface of the separating wall, and the yoke is pressed against these convex portions in the case where the yoke is press-fit. The first convex portion and the second convex portion are formed in a ring shape around the rotational axis of the motor. The diameter of the first convex portion is less than the diameter of the second convex portion.