Patent ID: 6724116
Filing Date: 2004-04-20
Classification: H02K

Abstract:
A rotor assembly for an alternator comprising:a shaft defining an axis of rotation; a first pole piece mounted onto said shaft and having an outer periphery; a second pole piece mounted onto said shaft coaxial with said first pole piece, said second pole piece including an outer periphery; an excitation winding positioned between said first and second pole pieces; a plurality of first pole fingers circumferentially spaced about said periphery of said first pole piece and extending axially from said periphery generally parallel to said axis of rotation; a plurality of second pole fingers circumferentially spaced about said periphery of said second pole piece and extending axially from said periphery generally parallel to said axis of rotation; a plurality of permanent magnets positioned on said periphery of said first and second pole pieces and being located between adjacent ones of said fingers, said permanent magnets each including a through hole formed therein; a plurality of fasteners, one of said fasteners extending through said through hole of one of said permanent magnets and engaging one of said first and second pole pieces to secure said permanent magnets thereon; and a plurality of plates, one of said plates being positioned on a top surface of each of said permanent magnets and secured thereto by said fasteners, said plates covering only a portion of said top surface of said permanent magnets.