Patent Number: 7,784,168

Title: Magnet protection mechanism for magnet body in rotor and magnet protection method

Abstract: A magnet covering member made of a soft steel plate covers an outer surface of a magnetized permanent magnet placed in a rotor core of a rotor. The magnet covering member is detached from the permanent magnet when the rotor is incorporated into a stator of an alternator during an alternator assembling process. Because of a soft magnetic characteristic of the magnet covering member, an outer magnetic field generated by the permanent magnet placed between adjacent claw poles of the rotor core makes a magnetic short-circuit, and a magnetic attracting phenomenon caused by such a magnetic field is thereby reduced. The soft magnetic characteristic of the magnet covering member also serves to support the rotor.

Inventors: Ooiwa; Tooru (Toyota, JP)

Assignee: Denso Corporation

International Classification: H02K 15/10 (20060101)

Expiration Date: 8/31/12018