Noiseless alternator for motor vehicle - has ferromagnetic shunt plates reducing flux variation in front of stator slots

摘要

The alternator has a magnetic shunt arranged so that the reluctance of the magnetic circuit is very much greater when the rotor's excitation poles are opposite the stator slots than when opposite the stator's armature. The magnetic shunt consists of a ferromagnetic plate between the projections of the stator slots and the insulating collar that separates the projections. Alternatively, the shunt may comprise the slot projections themselves. The variation in the magnetic flux cutting the poles in front of the slots is thus limited and the acoustic noise reduced accordingly.