Patent ID: 7560837
Filing Date: 2009-07-14
Classification: H02K

Abstract:
1. An automotive alternator comprising: a rotary shaft; a pulley provided on said rotary shaft so as to transmit a rotating power from an engine to said rotary shaft; a stator including a stator winding; a rotor mounted on said rotary shaft and surrounded by said stator, said rotor being configured to provide a first rotating magnetic field to said stator; and a magnetic fluctuation suppressor including a magnetic body, which is made of a magnetic material and has a predetermined mass, and a magnetic source, said magnetic body being mounted on said rotary shaft such that said magnetic body is rotatable along with said rotary shaft at a rotational speed different from that of said rotary shaft, said magnetic source being fixed to said rotary shaft so as to provide said magnetic body with a second rotating magnetic field which causes said magnetic body to produce a magnetic attraction to said magnetic source by which fluctuations in rotational movement of said rotary shaft are suppressed, wherein said magnetic source of said magnetic fluctuation suppressor has the same number of magnetic poles as said rotor.