| 摘要 |
PURPOSE:To obtain a small-sized electromagnetic rotating machine, cost of which is reduced, by making the offset component of the change of magnetic field intensity generated by one of two electromagnetic coupling elements installed on the rotor side and the stator side, affecting to the other, to 1ppr. CONSTITUTION:A change by the revolution of a rotor 4 in a magnetic field generated by an FG magnet 2 is detected by a generating wire element 7a. The output signal of the generating wire element 7a generates sixty pulses pre one revolution (sixty ppr) because one hundred and twenty magnetizing inversion is executed to the pattern of the magnet 2. When the generating wire element 7a is disposed within a fan-shaped range at 45 deg. to the whole circumference of the FG magnet 2 because the magnet 2 is offset and magnetized, a rotational position signal can be formed from an offset modulation component. Accordingly, a rotary magnet exclusive for a conventional index and an element for detecting a rotational position can be omitted, thus allowing miniaturization. |
