DISK DRIVE

摘要

PURPOSE: To prevent the crash of ball bearing at the device having a small from factor by providing a crash preventing ring inside of a rotator around a shaft and making the ring of a size allowing only a small amount of movement of the rotator with respect to the shaft. CONSTITUTION: In a spindle driving motor, a crash preventing ring 60 is inserted to the inside 64 of the rotator 18 to be engaged with it and to support it. The ring is formed so that a slight space or interval 66 may remain between the inner diameter 68 of the ring 60 and the shaft 12. Similarly a crash ring 62 is inserted to the inner cylindrical surface 64 of the rotator 18 to support. A small space 70 is left between the ring 62 and the shaft 12. At the time of trying to rotate the rotator 18 around a point P2 and another similar point along the shaft of the shaft 12, the rings 60 and 62 are shifted toward the outer periphery of the shaft 12 substantially in the direction of a radius and the space 66 and 70 are closed to be engaged with each other as the result. Then the movement of the rotator 18 in the direction of an arrow 32 is restricted to prevent the permanent plasticity deformation of bearing assemblies 16 and 17.