| 摘要 |
PROBLEM TO BE SOLVED: To greatly improve reliability and operability by reducing a continuation period during lift-off transition and contact during this period. SOLUTION: A lower structure includes the base end of a spindle 52, a bearing sleeve 57, grooved upper and lower plates 64, 66 and a rotary flux plate 68 serving as a lower balancing member. A motor mechanism includes a circuit board 70 mounted on a housing and provided with a motor driving coil and a motor magnet 72 mounted on the upper rotary flux plate integrally formed on a bearing sleeve. With the rotation of the rotor mechanism, a thin gas film is produced in a gap of a thrust plate. the bearing surface of an upper thrust plate is levitated from the bearing surface of a lower thrust plate to cause the rotor mechanism to be changed into a stationary state and thus rotated at the maximum speed, preventing the contact of a spindle 52 or a hologon system with another portion. |
