TURNTABLE OF SPINDLE MOTOR

摘要

PROBLEM TO BE SOLVED: To prevent a disk from detaching by providing a bottomed annular groove in the central part, fitting a disk attracting ring magnet into it and providing a mechanical means for pressing the ring magnet. SOLUTION: A rotary shaft 2 is fixed by force fitting a holding part 4 into a turntable 3 or the like. A placing surface 5 for a medium such as a disk is provided in the outer peripheral part of the turntable 3. A hub 6 is fitted into the central hole of the disk or the like. A bottomed annular groove 7 is provided in the outer periphery of the holding part 4. A side surface annular groove 9 which is provided in the upper part of the bottomed annular groove 7 is provided in a position a little higher than the upper surface of the ring magnet 8. A spring washer 10 is engaged with inward facing projections in the side surface annular groove 9 and pressed by spring force, and plural number of inward facing projections are provided toward the center. The ring magnet 8 is pressed by engaging the projections of the spring washer 10 with the side surface annular groove 9 which is provided in the side surface of the bottomed annular groove 7.