Patent ID: 6433457
Filing Date: 2002-08-13
Classification: H02K

Abstract:
A brushless AC generator including a stator having a stator core and an armature coil, a rotor having a shaft, a frame for supporting said stator and said rotor, a pulley fixed to an end of said shaft to be driven by a belt, a pulley-side bearing supported by said framed at a portion near said pulley and anti-pulley-side bearing supported by said frame at a portion remote from said pulley, whereinsaid rotor comprises a magnetic pole core having a plurality of circumferentially and equally disposed and alternately polarized magnetic pole pieces, a rotary yoke integrated with a group of said magnetic pole pieces that are polarized in one polarity and fixed to said rotary shaft; a stationary yoke is interposed between the other group of said pole pieces that are polarized in the other polarity and said rotary yoke and a field coil fixedly surrounded by said magnetic pole core; said anti-pulley-side bearing has a higher magnetic permeability than said pulley-side bearing.