Cooling arrangement of alternator

摘要

An alternator (1) disposed in the engine compartment of a vehicle is composed of a rotor (3) having magnetic poles (73) and a field coil (8), a cooling fan member (11, 12), a stator (2) disposed around the rotor (3) and having a stator core (32) and a multi-phase stator winding (21). The multi-phase stator winding (2) has a plurality of conductor segments (33) each having a U-turn portion (33c) to form a first coil-end group (31c) and a pair of joint portions (33d) to form a second coil-end group (31d). The first coil-end group (31c) is disposed where temperature is higher than the other end, and the second coil-end group (31d) is disposed on the other end. The cooling fan member (11, 12) sends cooling air to the second coil-end group (31d) less than the first coil-end group (31c).