| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a speed detector of a system different from the one in the conventional case. <P>SOLUTION: A speed detector comprises: a rotational axis; a permanent magnet fixed to the rotational axis; first and second rotational iron cores which are fixed to the rotational axis, excited to mutually different polarities by the permanent magnet and whose shapes are the same; a fixed iron core including a cylinder part which surrounds the first and second rotational iron cores, a support part projected from the inside of the cylinder part, and an opposite part provided at the tip of the support part to face the first and second rotational iron cores; and a coil wound round the surroundings of the support part. The opposite part has a plurality of fixed teeth, the first rotational iron core has a plurality of first rotational teeth, and the second rotational iron core has a plurality of second rotational teeth. Pitches of the fixed teeth, the first rotational teeth, and the second rotational teeth are the same, and the first and second rotational teeth are shifted by a half pitch. <P>COPYRIGHT: (C)2013,JPO&INPIT |
