Alternator for an automotive vehicle

An alternator for an automotive vehicle, comprising:

• a field rotor with N and S poles formed alternately in a circumferential direction, a stator disposed around said rotor in a confronting relationship, a frame supporting said rotor and said stator, and a rectifying AC power obtained from said stator in DC power, wherein
• said stator comprises a laminated stator core formed with a plurality of slots, and a plurality of conductor segments are accommodated in said slots;
• said conductor segments comprise a plurality of U-shaped segments, each having two straight portions accommodated in different slots spaced at an interval corresponding to a N-and-S magnetic pole pitch of said field rotor;
• said plurality of U-shaped segments have turn portions each serving as a coil end protruding in an axial direction from one end face of said stator core, said turn portions being mutually spaced so as to form a first coil end group;
• said plurality of slots comprises a plurality of slot groups, each slot group of one phase consisting of a plurality of slots spaced at predetermined intervals corresponding to the magnetic pole pitch of said field rotor, a first slot set being constituted by slot groups of multiple phases, and a second slot set being phase shifted from said first slot set by a predetermined electric angle,
• a first winding comprises said plurality of conductor segments accommodated in said slot groups included in said first slot set and a second winding comprises said plurality of conductor segments accommodated in said slot groups included in said second slot set, and said first winding of multi-phase and said second winding of multi-phase are combined so as to generate a summed up output and are accommodated in said slot groups to be disposed a substantially equal distance in the radial direction from the center of the stator core,
• said plurality of U-shaped segments have end portions protruding in an opposite axial direction from the other end face of said stator core, said end portions are connected according to a predetermined connecting pattern so as to constitute coil ends of a winding, and said coil ends are mutually spaced so as to form a second coil end group;
• said field rotor comprises a Lundel-type core having a plurality of hooked magnetic poles serving as said N and S poles, and
• two ventilation passages are provided at both axial ends of said field rotor, one ventilation passage extending in a radial direction so as to allow air to flow across said first coil end group, and the other ventilation passage extending in a radial direction so as to allow air to flow across said second coil end group.

An alternator for an automotive vehicle, comprising:

• a field rotor with N and S poles formed alternately in a circumferential direction, a stator including a stator core disposed in a confronting relationship with said rotor and a multi-phase stator winding associated with said stator core, and a frame supporting said rotor and said stator, wherein
• said stator has a plurality of slots for accommodating said multi-phase stator winding,
• said plurality of slots comprises a plurality of slot groups, each slot group of one phase consisting of a plurality of slots spaced at predetermined intervals corresponding to the magnetic pole pitch of said field rotor, a first slot set being constituted by slot groups of multiple phases, and a second slot set being phase shifted from said first slot set by a predetermined electric angle,
• said multi-phase stator winding comprises a plurality of conductor segments,
• said plurality of conductor segments constitute at least one pair, and are inserted in said slots so as to constitute an inner layer and an outer layer arranged in a depth direction of each said slot, and said conductor segments are insulated from each other in each said slot,
• said plurality of conductor segments are partly disposed out of said slots external from an end face of said stator core and form a plurality of coil ends of serially connecting different layers disposed in different ones of said slots spaced at an interval corresponding to a magnetic pole pitch of said field,
• said multi-phase stator winding comprises a first winding of said plurality of conductor segments accommodated in said slot groups included in said first slot set and a second winding of said plurality of conductor segments accommodated in said slot groups included in said second slot set, and said first winding of multi-phase and said second winding of multi-phase are combined so as to generate a summed-up output, and
• said coil ends provide a substantially identical heat radiation surface for each winding of each slot group.