Patent attributes
The vehicle-use alternator includes a cooling fan rotating in one with a rotating shaft thereof to generate cooling air diffusing substantially in a radial direction of the rotating shaft, to thereby cool a stator thereof. A housing thereof rotatably supporting the rotating shaft and housing the rotor is provided with a plurality of supporting members circumferentially spaced on a periphery thereof to which the stator is secured, and a plurality of ribs formed on the periphery which are circumferentially arranged between the supporting members so as to form a plurality of cooling air discharge windows circumferentially arranged on the periphery. The ribs are inclined towards a downstream side with respect to a rotational direction of the rotor, and shaped that their inclination angles towards the downstream side between two adjacent ones of the supporting members reduce with increasing distance from a closer one of the two adjacent ones of the supporting members.