Electromagnet, with a permanent magnet to give a second magnetic field, has a magnet shunt with adjustable positioning to compensate for production tolerances

摘要

The electromagnet (1) has a soft magnetic housing (2) to generate an initial magnetic field, an excitation coil and a permanent magnet (7) to generate a second magnetic field. A sliding armature (4) moves centrally within the coil. The permanent magnet is mounted within the housing so that the second magnetic field in the armature overlays the first field. A magnet shunt (8), with position adjustment, forms a magnetic shunt for the permanent magnet in its vicinity. The magnet shunt is shaped to give an air gap surface (11) and an inner surface of the housing forms a shunt gap (9), adjustable through the positioning of the magnet shunt.