WATTHOUR METER WITH A SHIELDED MAGNETIC BEARING

摘要

A watthour meter comprises a magnetic bearing having a pair of magnets (3, 4) rotatably supporting a rotatable disc (1) and a braking device (10) having braking upper and lower magnets (10a) for applying a braking torque to the rotatable disc, and a magnetic shield (9) is disposed between the magnetic bearing and the braking device for preventing leakage flux from the braking device from interfering with the magnetic flux of the magnetic bearing.