Patent ID: 6455972
Filing Date: 2002-09-24
Classification: H02K

Abstract:
An alternator comprising:a rotor for formning north-seeking (N) and south-seeking (S) poles about a rotational circumference; a stator comprising: a stator core disposed facing said rotor; and a polyphase stator winding installed in said stator core; and a bracket supporting said rotor and said stator, wherein said stator core comprises a laminated iron core two axial end surfaces and a plurality of slots extending in an axial direction at a predetermined pitch in a circumferential direction, said polyphase stator winding comprises a number of winding sub-portions each formed of a long strand of wire which is wound so as to alternately occupy an inner layer and an outer layer in a radial direction within said slots at intervals of a predetermined number of slots, said strand of wire folding back outside said slots at axial end surfaces of said stator core to form turn portions extending from said axial directions, and said number of winding sub-portions being constructed with at least one winding assembly formed by simultaneously bending and folding a plurality of said strands of wires, wherein said winding assembly is constructed by arranging at one slot pitch offset the same number of wire-strand pairs as said predetermined number of slots, each of said wire-strand pairs being constructed by arranging two strands of wire so that straight portions alternately overlap at a predetermined pitch, each of said strands of wire being formed into a pattern in which said straight portions are connected by turn portions so as to be arranged at a pitch of said predetermined number of slots and adjacent straight portions are offset so as to alternately occupy said inner layer and said outer layer in said radial direction, and by extending each end portion of said strands of wire on both sides of both ends of said winding assembly and arranging the same number of pairs of said overlapping straight portions as the number of said slots at said one slot pitch, said turn portions align in said circumferential direction to constitute coil end groups extending from each of said axial end surfaces of said stator core, and said turn portions constituting said coil end groups extending from each of said axial end surfaces of said stator core are formed in the generally identical shape in a circumferential direction.