Electromagnetic actuator permanent magnet

摘要

An electromagnetic actuator has a stator core, an armature and a coil. The stator core is formed as a seamless cylindrical tube having a thin wall as a magnetic restrictor. The thin wall has a thickness sufficient to maintain a mechanical strength of the stator core. A permanent magnet is located on an outside of the thin wall to generate a magnetic flux passing through the thin wall in the same direction as a magnetic flux generated by the coil. The thin wall is magnetically saturated with the magnetic flux generated by the permanent magnet. When the coil is energized, a magnetic flux generated by the coil gets around the saturated thin wall and passes through the armature.