Abstract: It is an object of this invention to provide an alternator for a vehicle in which all electric conductors forming bridge portions are sufficiently exposed to cooling winds so that the cooling performance is remarkably improved. It is another object of this invention to provide an alternator for a vehicle which is excellent in cooling performance, insulating characteristic, and heat resisting property. An alternator for a vehicle includes a stator. The stator includes an iron core 22, an electric conductor 21, and an insulator 23. The electric conductor 21 forms a winding on the iron core 22. The insulator 23 provides electric insulation between the electric conductor 21 and the iron core 22. The stator is supported by a housing. The dimension of openings of slots in the iron core 22 is smaller than the distance between inner side surfaces of the slots. The electric conductor 21 has accommodated portions accommodated in the slots, and bridge portions connecting the accommodated portions.

Abstract: It is an object of this invention to provide a compact high-power alternator for a vehicle. An alternator for a vehicle includes a stator serving as an armature, and a rotor serving to generate a magnetic field. The rotor includes a pole core having a cylindrical portion, a yoke portion, and a claw-like magnetic pole portion. The stator includes a stator iron core, an armature coil, and an insulator. A ratio L1/L2 of an axial-direction length L1 of the stator iron core to an axial-direction length L2 of the pole core is in a range of 0.7 to 1.0.

Abstract: An alternator for a vehicle includes a stator, a rotor and a pair of cooling fans fixed on opposite sides of the rotor. The stator winding is composed of a conductor group disposed in the stator core and a pair of annular coil-end groups extending from the conductor group to be disposed on opposite sides of said stator core. Each of the coil-end groups has a plurality of coil ends which has a pair of inclined portion, and each one of the inclined portion disposed at the outermost circumference of the coil-end groups inclines to guide the cooling air spirally in an axial direction.

Abstract: The present invention provides a compact, efficient and noiseless alternator for an automotive vehicle which employs a double-layer coil arrangement in a slot for eliminating coil end interference as well as improving the space factor. An automotive alternator comprises a Lundel-type core rotor with 16 poles, and a stator with toothed portions of 96 poles spaced by slots. U-shaped conductor segments are installed in the slots. One portion of the conductor is accommodated in an outer layer portion of a predetermined slot, while the other portion is accommodated in an inner layer portion of a slot phase shifted by an electric angle of 180.degree.. In this manner, all of the slots are separated into the inner and outer layers to accommodate a plurality of conductor segments. These conductor segments are connected only at one side of the stator to form a total of twelve wavy winding coils.

Abstract: A stator winding has a plurality of conductor members forming coil ends, and each of the conductor members of the coil ends is hardened and heat treated to have hardness which changes along the length of conductor members. Therefore, the stiffness of the coil ends changes and resonant vibration of the stator can be reduced.

Abstract: A stator winding is composed of a first and second of three-phase windings. Each of them has three separate Y-connected or .DELTA.-connected coils which are wound on the teeth of the stator core at a 2 .pi./3 short pitch. The second three-phase winding is shifted from the first winding by .pi./3 radian in the electric angle which is one tooth pitch.

Abstract: An alternator for a vehicle includes a stator having a stator core, a stator winding having a first coil-end group and a second coil-end group on the opposite ends of the stator core The alternator further includes a rectifier disposed near the first coil-end group and an air drive unit for cooling the first and second coil-end groups. Because the first coil-end group has a larger surface to be cooled than the second coil-end group, temperature of both coil end groups is controlled so that they become equal.

Abstract: In a stator of an alternator for a vehicle including a stator core and a multi-phase stator winding, the stator winding is composed of a plurality of conductor segments having a pair of conductor members connected with one another to form a first coil-end group disposed on one axial end of the stator core so that first U-turn portions of the conductor segments are surrounded by second U-turn portions of the conductor segments and a second coil-end group disposed on the other axial end of said stator core so that ends of said conductor segments are connected to form lap windings.

Abstract: An alternator for a vehicle includes a fan for supplying cooling air along an inner circumference of coil-end groups disposed opposite ends of a stator in an axial direction. Each of the coil-end groups is composed of a plurality inner coil-end portions disposed at an inner circumference of the coil-end groups to extend from an end of the stator core and outer coil-end portions disposed at an outer circumference of the coil-end groups to extend from an end of the stator core. The inner coil-end portion extends in a direction between the axial direction and rotating direction of the rotor.

Abstract: An alternator for a vehicle which maintains or improves the cooling performance and which reduces the fan noise caused by the interference between the cooling winds and the stator windings. An armature coil provided on a stator of the alternator includes an X-phase coil group, a Y-phase coil group, and a Z-phase coil group. Coil end groups are sets of coil ends forming bridge wires between slots. The coil end groups have stationary blade shapes which form passages for the cooling winds directed from a cooling fan on a rotor toward outlets in a frame. The sound of the interference between the cooling winds and the coil end groups is reduced while the cooling performance is enhanced.

Abstract: The coil-end portions of an armature winding are disposed around cooling fans and closely, and outer coil ends of the coil-end portions are disposed to be close to alternator frames via insulating layers. The coil ends are spaced apart from one another except the base portions, and the resistance of cooling air draft inside the coil-end portions is lower than that around the coil-end portions so that the cooling air mainly passes through the inside of the coil-end portions.

Abstract: An alternator disposed in the engine compartment of a vehicle is composed of a rotor having magnetic poles and a field coil, a cooling fan member, a stator disposed around the rotor and having a stator core and a multi-phase stator winding. The multi-phase stator winding has a plurality of conductor segments each having a U-turn portion to form a first coil-end group and a pair of joint portions to form a second coil-end group. The first coil-end group is disposed where temperature is higher than the other end, and the second coil-end group is disposed on the other end. The cooling fan member sends less cooling air to the second coil-end group than the first coil-end group.

Abstract: It is an object of this invention to provide an alternator for a vehicle in which all electric conductors forming bridge portions are sufficiently exposed to cooling winds so that the cooling performance is remarkably improved. It is another object of this invention to provide an alternator for a vehicle which is excellent in cooling performance, insulating characteristic, and heat resisting property. An alternator for a vehicle includes a stator. The stator includes an iron core 22, an electric conductor 21, and an insulator 23. The electric conductor 21 forms a winding on the iron core 22. The insulator 23 provides electric insulation between the electric conductor 21 and the iron core 22. The stator is supported by a housing. The dimension of openings of slots in the iron core 22 is smaller than the distance between inner side surfaces of the slots. The electric conductor 21 has accommodated portions accommodated in the slots, and bridge portions connecting the accommodated portions.

Abstract: The present invention prevents the degradation of the power generating efficiency of an alternating current generator by preventing the expansion of an air gap formed between pole cores and a stator core, achieves low-noise operation by preventing generation of high-frequency impact magnetic noise, and makes it possible to relieve strains applied on a magnet holder. The present invention utilizes sixteen magnets, each of which fits between two of sixteen claw-like magnetic poles formed on the outer periphery of Lundell-type pole cores, which rotates integrally with a shaft. The magnets are caught and stopped by a magnet holder which has been formed by interconnecting zig-zagging segments and has elasticity as a whole. Here, the permanent magnets are held by the magnet holder so that the magnet holder does not protrude towards the rotor side from the outer peripheral face of the Lundell-type pole cores and the contacting faces of the magnet holder contact the outer faces of the permanent magnets.

Abstract: In a rotor of an AC generator for a vehicle, a coil bobbin, around which rotor coil is wound, includes a bobbin body having a first through hole at a winding drum portion and is made of hard resin. A first hole member is kept at the first through hole and is made of good thermal conductivity rubber. An outer peripheral layer is formed integrally with the first hole member and is made of good thermal conductivity rubber covering the outer peripheral surface of the winding drum portion. An improved rotor of an AC generator for a vehicle is provided, in which a regular winding property of the rotor coil is improved and at the same time, heat of the rotor coil can be more effectively radiated to the rotor core side so that generator output can be improved.

Abstract: The present invention prevents the degradation of the power generating efficiency of an alternating current generator by preventing the expansion of an air gap formed between pole cores and a stator core, achieves low-noise operation by preventing generation of high-frequency impact magnetic noise, and makes it possible to relieve strains applied on a magnet holder. The present invention utilizes sixteen magnets, each of which fits between two of sixteen claw-like magnetic poles formed on the outer periphery of Lundell-type pole cores, which rotates integrally with a shaft. The magnets are caught and stopped by a magnet holder which has been formed by interconnecting zig-zagging segments and has elasticity as a whole. Here, the permanent magnets are held by the magnet holder so that the magnet holder does not protrude towards the rotor side from the outer peripheral face of the Lundell-type pole cores and the contacting faces of the magnet holder contact the outer faces of the permanent magnets.

Abstract: In an on-vehicle alternator, both the magnetic flux variation frequency and maximum flux density are decreased sufficiently to thereby decrease the internal iron loss and thereby realize an increase in the current generation efficiency. The on-vehicle alternator comprises a rotor wherein magnetic pole cores that are polarized by a rotor coil to alternately different polarities are circumferentially disposed on the outer periphery thereof at prescribed equi-angular intervals. A permanent magnet which is embedded within a resin-made retainer body is provided between the magnetic pole cores and has side faces, as viewed circumferentially, which are polarized respectively to the same polarities as those of adjacent respective magnetic pole cores to thereby vary the magnetic flux quantity directed toward stator coils so as to exhibit a circumferential gentle curve.

Abstract: Rectifying elements that constitute a full-wave rectifier of an on-vehicle alternator are constituted by Schottky barrier diodes. The Schottky barrier diode has on one hand the drawback that rectifying characteristics thereof deteriorate due to the heat generation resulting from large avalanche breakdown current that is produced due to surge voltage, with the result that leakage current that occurs when reverse voltage is applied increases. However, according to the present invention, since the surge voltage is absorbed by a voltage regulation diode connected in parallel with the Schottky barrier diode, the voltage regulation diode is broken down when surge voltage has been applied. Accordingly, it does not happen that reverse voltage that exceeds the breakdown voltage of the voltage regulation diode is applied to the Schottky barrier diode. Therefore, it does not happen that the current due to surge voltage exceeding the breakdown voltage thereof flows in the Schottky barrier diode.

Abstract: An alternator includes MOSFETs used as rectifiers which are sealed by a sealing member (for example, a molded epoxy resin) together with heat radiating fins and an external input/output terminal plate. The sealing member can evenly dissipate stress even if the radiating fins, terminal plate, and the like vibrate with different phases. Since the rectifying elements are reliably secured even when subjected to great vibrations, damage to the MOSFETs can be suppressed. The MOSFETs are never exposed to atmospheric air since the MOSFETs are sealed by the sealing member. Therefore, the alternator can improve the MOSFETs' resistance against adverse operational conditions.