| 摘要 |
A spindle motor includes a rotary shaft, a stator including a coil wound on a core around the shaft, a rotor including a magnet in a yoke combined with the shaft which faces the core and the yoke, and a turn table combined with the rotor and having a groove for a ball. A ratio (Yr/Bd) of an external radius (Yr) of the yoke to a diameter (Bd) of the ball ranges from 4.6 to 4.9 in order to reduce a vibration of the turn table and the rotor. |
