ROTARY SOLENOID

PURPOSE:To simplify the structure of a rotary solenoid so as to reduce the cost of the solenoid and make the solenoid compacter by constituting the solenoid in such a way that, when a coil is energized so that the polarities of a permanent magnet and yoke can become the same, the magnet is rotated to the positions of opposite poles of the yoke in the direction opposite to the direction in which the coil is not energized. CONSTITUTION:A permanent magnet 3 is connected with a shaft 1 so that the magnet 3 can be rotated when the shaft 1 rotates. A fixed magnetic pole is composed of a yoke 2 and coil 4 and constitutes a magnetic circuit. A rotating permanent magnet 3 is maintained at such a rotational position where the magnetic poles of the magnet 3 come into contact with both poles of the yoke 2. When the coil 4 is not energized, a strong coercive force is generated by the magnetic force of the magnet 3 and the magnet 3 is fixed to the yoke 2 at the rotational position. When the coil 4 is energized so that the polarity of the magnet 3 can become the same as that of the yoke 2, a repulsive force is generated and the magnet 3 starts to rotate. After starting rotation, attracting forces act between the poles of the magnetic 3 and opposite poles of the yoke 2 and a strong rotational force is obtained.