An electromagnetic machine includes a rotor having a plurality of poles and a stator also having a plurality of poles. The poles for the rotor are divided into a first and second set of radially opposed pairs. The first set has uniform faced poles. The second set has a notched face. The stator includes...http://www.google.ca/patents/US6720686?utm_source=gb-gplus-sharePatent US6720686 - Reduced noise dynamoelectric machine
