| 摘要 |
PURPOSE:To attain the miniaturization, electric power saving and high performance by forming a stator coil by a superconductive material, by providing a means to detect a back electromotive force to occur in a stator coil as a position signal and providing a supporting means to support a fixed part with a magnetic repulsive force at a motor for rotating and driving directly combined to the rotating body structure to mount a head. CONSTITUTION:The flat stator of a motor is provided between the magnetic pole surface of a stator magnet 5 and a rotation yoke 13, and a stator coil 7 composed of a superconductive material and a floating force generating coil 12 composed of the superconductive material in the same way are laminated. After activation, when the number of rotations arrives at a prescribed value of above, the motor detects the back electromotive force of the stator coil 7, and thus, is switched to a direct current brushless motor driving system to control and feed a coil current to the stator coil 7. By the rotation magnetic field from magnets 5, 18 and 18', a shorting induced current flows and thus, the repulsive force occurs and floats at the magnets 5, 18 and 18'. Consequently, in the steady rotation condition, a rotating part is completely in the non-contact condition for the fixed part both in a thrust direction and in a journal direction and in a low friction supporting condition. |
