| 摘要 |
PURPOSE:To improve the jitter of FG output voltage, by a method wherein a disc-formed yoke is bonded to a disc-formed permanent magnet to be put together, and wherein the neutral zone is met with the neutral zone of a magnetizer and a plurality of poles are magnetized at the same time. CONSTITUTION:A direct drive servo-motor is formed with a motor spindle 1, a cup-formed yoke 3, a disc-formed permanent magnet 4 provided for a plurality of poles in the direction of thickness, FG substrate 5, a motor driving coil 6, a motor yoke 9 and the like. Then, the neutral zone width of a magnet is made to coincide with the disc-formed yoke 13, and radial grooves 13-13h are provided with the center for a rotor, and the yoke 13 is fixed to the effective pole face of the disc-formed magnet 4 with bonding agent 14. The neutral zone 13i and magnetic pole pitch 13j are formed with etching or the like, and the accuracy is improved. The neutral zone is made to coincide with with the neutral zone of a magnetizer and a plurality of poles are magnetized with the magnetizer at the same time. |
