Abstract: An AC generator for a vehicle includes front and rear bearings held by a housing, a stator disposed in the housing, a rotor having a rotation shaft rotatably supported by the front and rear bearings, and a multiple-helical wave washer disposed to apply a pre-load to at least one of outer rings of the front and rear bearings. The housing includes a front frame that has a front bearing box for holding the front bearing, and a rear frame that has a rear bearing box for holding the rear bearing, and the stator is disposed between the front frame and the rear frame. In addition, the multiple-helical wave washer can contact the outer ring of the rear bearing and a side wall of the rear bearing box. Accordingly, creep resistance of the rear bearing is improved within an allowable pre-load range.

Abstract: An AC generator for a vehicle includes front and rear bearings held by a housing, a stator disposed in the housing, a rotor having a rotation shaft rotatably supported by the front and rear bearings, and a multiple-helical wave washer disposed to apply a pre-load to at least one of outer rings of the front and rear bearings. The housing includes a front frame that has a front bearing box for holding the front bearing, and a rear frame that has a rear bearing box for holding the rear bearing, and the stator is disposed between the front frame and the rear frame. In addition, the multiple-helical wave washer can contact the outer ring of the rear bearing and a side wall of the rear bearing box. Accordingly, creep resistance of the rear bearing is improved within an allowable pre-load range.

Abstract: A vehicle AC generator includes a rotor, a stator, a frame supporting the rotor and the stator, a rear cover having an air intake window, a rectifying unit including a pair of cooling fins and a plurality rectifier elements, a brush unit including a pair of brushes and a brush-holder, a connector case having a terminal for transmitting and receiving electric signals and an IC regulator. The pair of cooling fins has a common cutout section forming an accommodation space between the frame and rear cover, and the connector case is disposed in the accommodation space so as to form a cooling air passage connecting the air intake window around the connector case. The IC regulator is disposed in the cooling air passage to face the rear cover so that the heatsink is disposed opposite the air intake window. Therefore, the IC regulator is cooled effectively and direct heat radiation on the IC regulator from the cooling fins and the brush holder is prevented.

Abstract: A cooling fin is fixed to a frame and mounts a plurality of rectifying elements. The cooling fin is configured into a circular ring shape separated at a cutout section. A brush holder, a connector casing and an IC regulator are disposed in this cutout section. A circumferential gap of the cutout section is smaller than three times a circumferential width of the brush container.

Abstract: A vehicle AC generator includes a rotor, a stator, a frame supporting the rotor and the stator, a rear cover having an air intake window, a rectifying unit including a pair of cooling fins and a plurality rectifier elements, a brush unit including a pair of brushes and a brush-holder, a connector case having a terminal for transmitting and receiving electric signals and an IC regulator. The pair of cooling fins has a common cutout section forming an accommodation space between the frame and rear cover, and the connector case is disposed in the accommodation space so as to form a cooling air passage connecting the air intake window around the connector case. The IC regulator is disposed in the cooling air passage to face the rear cover so that the heatsink is disposed opposite the air intake window. Therefore, the IC regulator is cooled effectively and direct heat radiation on the IC regulator from the cooling fins and the brush holder is prevented.

Abstract: A vehicle AC generator includes a pair of front and rear frames fastened by a plurality of stud bolts at peripheral portions thereof, a stator having a multi-phase armature winding supported by the pair of frames, a rotor disposed radially inside the stator, a rectifier unit having a positive cooling fin holding a plurality of positive diodes, a connection member, and a negative cooling fin holding a plurality of negative diodes. The positive cooling fin is fastened by the plurality of stud bolts together with the pair of frames separate from the negative cooling fin, and the connection member is disposed between the positive cooling fin and the negative cooling fin. The connection member has a circuit for electrically connecting the armature winding and the rectifier unit, which is covered by an insulation member.

Abstract: A larger-diameter fin is provided adjacent to a frame, while a smaller-diameter fin is provided adjacent to a protecting cover. The larger-diameter fin and the smaller-diameter fin are arranged parallel to each other in an axial direction with an intervening clearance so that their rectifying elements are disposed at opposite directions each other. The larger-diameter fin is offset outward in a radial direction. The smaller-diameter fin is offset inward in the radial direction. The protecting cover has an axial opening which introduces external air directly to the positive rectifying element. Furthermore, a radial ventilation passage is formed between the larger-diameter fin and the frame so as to pass the central position of the negative rectifying element. An opening, introducing external air directly, is formed at a radial-outer end of the radial ventilation passage.

Abstract: A cooling fin is fixed to a frame and mounts a plurality of rectifying elements. The cooling fin is configured into a circular ring shape separated at a cutout section. A brush holder, a connector casing and an IC regulator are disposed in this cutout section. A circumferential gap of the cutout section is smaller than three times a circumferential width of the brush container.

Abstract: A rectifier arrangement of an alternator for a vehicle includes a frame and a cover for a rectifier. The rectifier arrangement is composed of a plus-potential cooling-fin disposed in a space between the cover and the frame at a portion close to the cover in parallel therewith, a minus-potential cooling-fin disposed in the space in parallel with the plus-potential cooling-fin, a fastening member fixed to the frame and extending through mounting holes of the plus-potential and minus-potential cooling fins, a cylindrical bushing made of thermosetting resin disposed in a space formed by the cover, plus-potential cooling-fin and fastening member.

Abstract: A larger-diameter fin is provided adjacent to a frame, while a smaller-diameter fin is provided adjacent to a protecting cover. The larger-diameter fin and the smaller-diameter fin are arranged parallel to each other in an axial direction with an intervening clearance so that their rectifying elements are disposed at opposite directions each other. The larger-diameter fin is offset outward in a radial direction. The smaller-diameter fin is offset inward in the radial direction. The protecting cover has an axial opening which introduces external air directly to the positive rectifying element. Furthermore, a radial ventilation passage is formed between the larger-diameter fin and the frame so as to pass the central position of the negative rectifying element. An opening, introducing external air directly, is formed at a radial-outer end of the radial ventilation passage.