The invention relates to a permanent
magnetism mechanism, which comprises an upper case body and a lower case body, wherein, a movable core is arranged between the upper case body and the lower case body; the upper part of the movable core is provided with three upper guide levers. Both sides of the upper guide lever positioned at the middle are provided with a
tripping spring and a
tripping spring adjusting screw. The upper part of the upper guide lever is provided with an insulator and a contact spring. The position where the lower part of the movable core corresponds to the upper guide lever is provided with a hand trip gear, and both sides of the movable core are provided with a closing coil and a permanent
magnet. The invention has the advantages that
linear drive is realized on a three step switch tube and the synchronicity and the
operability of the three step action are more reliable; the adjustment of the speed of a trip also can be realized; the structure is simple; the cost is low. The invention can be widely used for a breaker and a
contactor of a mine feed
system, and the environment of the mine feed
system is vile, and the mine feed
system has high requirement for the reliability. Because the invention only adopts one closing coil, the space of the closing coil is increased. The number of turns of the closing coil can be increased on the premise that the coil
diameter is the same or greater than the
diameter of the primary coil. The invention can realize frequent
electrification for a long time and can not be burnt under the condition that
ampere-turn is invariable or the
ampere-turn is properly enhanced.