Patent ID: 7633196

Claim:
A vehicle-use alternator comprising: a rotating shaft driven by a vehicle engine; a rotor having a field winding wound therearound and rotating in one with said rotating shaft; a stator having a stator winding wound therearound and fixed outwardly of said rotor; a cooling fan rotating in one with said rotating shaft to generate cooling air diffusing substantially in a radial direction of said rotating shaft, to thereby cool said stator; and a housing rotatably supporting said rotating shaft and housing said rotor, said housing being provided with a plurality of supporting members circumferentially spaced on a periphery thereof to which said stator is secured, and a plurality of ribs formed on said periphery which are circumferentially arranged between said supporting members so as to form a plurality of cooling air discharge windows circumferentially arranged on said periphery, said cooling air being discharged through said plurality of cooling air discharge windows; wherein said ribs are inclined with respect to a radial direction of said rotating shaft, and shaped such that inclination angles of said ribs located between two adjacent ones of said supporting members reduce with increasing distance from each one of said two adjacent ones of said supporting members.