Permanent magnet for e.g. electric motor has magnet main structure comprising permanent-magnetic core and two permanent-magnetic cases that are made of different permanent magnetic materials

摘要

The permanent magnet (1) has a magnet main structure comprising a soft-magnetic tubular socket (3) that is provided with air gap (5) for receiving an electrical winding (7). The magnet main structure is provided with a permanent-magnetic core (9) and two permanent-magnetic cases (11,13) that are made of different permanent magnetic materials. The core is made of rare earth permanent magnet material such as Neodymium-iron-boron alloy, and permanent-magnetic cases are made of aluminum nickel cobalt alloy.