JPH1198786A - Ac generator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the cooling performance, output and efficiency, to reduce the generation of heat, and to simplify the winding processes by preventing the crossing of connecting wires. SOLUTION: This generator is provided with a rotor 4 having field poles and a stator 5. In the stator 5, three-phases stator coils x, y, and z are lap- wound in a shout pitch form with a small diameter of 2π/3 on the inner surface of a stator core and the number of slots per pole per phase is 0.5 and teeth numbering three times as many as the number of slots are formed in to a ring shape. Each of the three-phases stator coils 'x', 'y' and 'z' is constituted of a plurality of coil sections (series conductors) 41, each of which is constituted of a coil side 43 placed inside a slot and a coil end placed outside the slot, and a plurality of connecting wires 42, each of which connects adjacent two coil sections 41. The coil sections 41 are wound successively into a ring shape, with the adjacent coil sections 41 sharing the same slot.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator in which an alternating current output is generated from a three-phase stator coil with rotation of a rotor having field poles, and more particularly to charging and electric power of a battery mounted on a vehicle. The present invention relates to an AC generator for a vehicle that supplies power to a device and an electric control device.

[0002]

2. Description of the Related Art In recent years, vehicle alternators have become smaller and more expensive due to an increase in the use of electric devices and electric control devices mounted on vehicles and a reduction in the space for mounting auxiliary equipment due to downsizing of an engine room. What is output is desired. Therefore, it is conceivable to improve the cooling efficiency as a means for increasing the output of the vehicle alternator.

For example, there is a conventional apparatus disclosed in Japanese Patent Application Laid-Open No. 3-226251. In this conventional device, a plurality of teeth are annularly arranged at equal angular intervals on the inner periphery of a stator core so as to have three teeth in a circumferential direction for two magnetic pole pitches of field poles. This is a vehicle alternator in which only one phase stator coil is wound around each tooth. This reduces the rate at which the stator coils of each phase overlap,
The cooling air contact exposed area around the stator coil of each phase is increased to increase the cooling performance.

A conventional apparatus disclosed in Japanese Patent Application Laid-Open No. 3-284147 is a vehicle AC generator in which the number of slots per pole and each phase is 0.5 and three-phase stator coils are concentratedly wound around teeth. Machine. As a result, the overall length of the three-phase stator coil is reduced, thereby lowering the resistance of the three-phase stator coil and suppressing the amount of heat generated. And cost reduction.

[0005]

However, in the conventional apparatus, even if the ratio of overlapping of the stator coils of each phase is reduced, the coil winding of each phase is not performed if the same coil winding method as in the related art is employed. The crossover of the coils connecting the so-called crossover wires is insufficient to prevent overlap, and the cooling air contact exposure area cannot be increased enough, and the crossover wires are lengthened to avoid crossover. Measures are required, and the shortening of the entire coil length becomes insufficient. As a result, a sufficient increase in output and efficiency cannot be expected.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to improve cooling performance and heat generation by preventing crossover of crossovers, thereby improving output, improving efficiency and facilitating the winding process. An object of the present invention is to provide an AC generator and a method for manufacturing the same.

[0007]

According to the first aspect of the present invention, the same slot is shared, and a plurality of coil sides to be wound are sequentially wound in an annular shape, so that the stator coil of each phase is formed. Since the main coil ends of the coil coils are not overlapped at the same time, and the connecting wires connecting the series conductors of the stator coil of each phase are all wound in the same direction, the connecting wires do not overlap, and the connecting wires do not overlap. Can be prevented from interfering with the coil end and hindering the winding, so that the effect of facilitating the winding with a coil length shorter than that of the conventional device can be obtained.

According to the second aspect of the present invention, the number of slots in the stator core is set to 0.5 per phase per pole, so that the stator core has the same number of field poles as the generator before the conventional device. Since the slot becomes large and the number of times of winding on the slot is reduced by half with respect to the generator before the conventional device, the winding operation becomes easy. Furthermore, even when the number of field poles is increased, the increase in the number of slots can be suppressed to half that of the generator before the conventional device. Thus, the effect that the output can be easily improved by the method can be obtained.

According to the third aspect of the present invention, each of the first stator coils of the short-wound first polyphase connection coil is connected to each of the second multi-phase connection coils similarly short-wound. Since the stator coils are wound in two layers with a shift of π / 3 radian in electrical angle, harmonic components included in the reaction magnetomotive force generated in the first and second stator coils during power generation can be canceled out and reduced. Therefore, the effect that the magnetic noise generated at the time of power generation can be significantly reduced can be obtained.

According to the third aspect of the present invention, since the first and second multi-phase connection coils are of the 2π / 3 short-coil winding type, the winding pitch is equal to the magnetic pole pitch of the field poles. The winding length of each of the first and second stator coils is shorter than that of a three-phase stator coil of a winding type, and the overlapping portion of each of the first and second stator coils is reduced. Thereby, the effect of increasing the cooling air contact exposed area around the first and second multi-phase connection coils and increasing the cooling efficiency is obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

FIGS. 1 to 5 show a first embodiment of the present invention. FIG. 1 is a diagram showing a winding structure of a three-phase stator coil, and FIG. It is a figure showing the whole alternating current generator structure.

The vehicle alternator 1 is a three-phase alternator that is disposed in front of a vehicle engine (not shown) in an engine room of the vehicle and receives rotational power to generate a three-phase alternating current. Further, the alternator charges a battery (not shown) mounted on the vehicle and supplies power to an electric device and an electric control device (neither is shown) mounted on the vehicle. The automotive alternator 1 includes a housing 2, a rotor 4 integrally rotatable with a shaft 3 rotatably supported by the housing 2, a stator 5 disposed opposite the rotor 4, and the like. ing.

The housing 2 includes a front housing 1
1, a rear housing 12 and a rear cover 13. The front housing 11 and the rear housing 12 are cases that support the stator 5 and, at the same time, are attached to a vehicle engine. Further, the front housing 11 and the rear housing 12 are joined by tightening using a fastener 14 such as a plurality of stud bolts and a plurality of nuts.

The front housing 11 and the rear housing 12 have a plurality of air inlets 15 and 16 for taking in cooling air and a plurality of air outlets 17 and 18 for discharging cooling air from the inside. It is open.
The rear cover 13 is coupled to the rear housing 12 by tightening the rear housing 12 using a fastener (not shown) such as a plurality of bolts and a plurality of nuts. The rear cover 13 has a plurality of air inlets (not shown) for taking in cooling air therein.

The rear housing 12 and the rear cover 1
3, a brush holder 19, a three-phase rectifier 20, a voltage regulator 21, and the like are accommodated. The brush holder 19 contains two brushes 22. The brush holder 19 is a box made of an electrically insulating resin in which two terminals for electrically connecting the two brushes 22 to the three-phase rectifier 20 and the voltage regulator 21 are insert-molded.

The three-phase rectifier 20 is a three-phase full-wave rectifier bridge circuit (rectifier) composed of rectifiers (diodes) 23 and 24 for rectifying an AC output generated by a three-phase stator coil described later and converting the output into a DC output. (Not shown), and a DC output terminal (not shown) for supplying a DC output to the battery. The voltage adjusting device 21 is, for example, a regulator that uses an IC regulator and controls an exciting current supplied to a rotor coil described later to adjust an output voltage of a three-phase stator coil.

The shaft 3 is rotatably supported on the inner peripheral side of the housing 2 via bearings (bearings) 25 and 26. A poly V pulley 27 is fastened and fixed between the nut with seat 28 and the bearing 25 at the tip of the shaft 3. The poly V pulley 27
It is drivingly connected to a V-belt pulley (not shown) mounted on an output shaft of a vehicle engine (drive source) via transmission means (not shown) such as a belt. The shaft 3
May be directly connected to the output shaft of the engine, or a transmission means such as one or more gear transmissions or a V-belt type continuously variable transmission may be connected between the shaft 3 and the output shaft of the engine.

The rotor 4 serves as a field, and has a rundle-type pole cores 31 and 32 facing the inner periphery of the stator 5; a rotor coil 33 wound around the pole cores 31 and 32; The rotor is composed of two slip rings 34 for supplying power to the coil 33, and cooling fans 35 and 36 for sucking cooling air into the housing 2.

The pole cores 31 and 32 are field poles according to the present invention. The pole cores 31 and 32 are rotor cores (rotor cores) having a central portion through which the shaft 3 penetrates and having 12 magnetic poles. Six claw-shaped magnetic pole pieces 31a, 32a are integrally formed on the outer peripheral side of the pole cores 31, 32, respectively. When an exciting current flows through the rotor coil 33, the pole cores 31 and 32 are magnetized, so that one of the claw-shaped magnetic pole pieces 31a becomes N-pole and all of the other claw-shaped magnetic pole pieces 32a become S-pole.

The rotor coil 33 is a field winding (field coil) that magnetizes the pole cores 31 and 32 when an exciting current flows, and is wound around the center of the pole cores 31 and 32 via a coil bobbin 37. . The coil bobbin 37 includes the pole cores 31 and 32 and the rotor coil 3.
3 is made of a resin member that electrically insulates the resin member 3 from each other.

The two slip rings 34 are connected to the shaft 3
Is fixed to the outer periphery of the rear end (the other end) by press fitting or the like. These slip rings 34 are made of an annular conductive metal (for example, a copper alloy), and supply an exciting current to the rotor coil 33 by sliding two brushes 22 on the outer peripheral surface.

The cooling fans 35 and 36 are means for cooling the heat-generating components of the vehicle alternator 1,
32 is integrally attached to the axial side wall surface by means such as welding. The cooling fan 35 has a shaft 3
An axial flow (mixed flow type) fan that generates cooling air in the axial direction and the radial direction (centrifugal direction) is used. As the cooling fan 36, a centrifugal fan that generates cooling air in the radial direction (centrifugal direction) of the shaft 3 is used.

Next, the structure of the stator 5 will be described in detail with reference to FIGS. Here, FIGS. 3 and 4 show a part of the winding state of the three-phase stator coil.
FIG. 3 is a diagram illustrating a method of winding a three-phase stator coil.

The stator 5 is a stator of the automotive alternator 1 and includes claw-shaped magnetic pole pieces 31 of the pole cores 31 and 32.
a, 32a are inserted into a plurality of slots 7 formed on the inner periphery of the stator core 6 facing the outer peripheral surface of the stator core 6, and the three-phase AC output is generated with the rotation of the pole cores 31, 32. It comprises three-phase stator coils x, y, z, etc. to be induced.

The stator core 6 is also called a stator core, a stator core, or an armature core, and is press-fitted into the inner peripheral surface of the front housing 11 to be integrated with the housing 2. The stator core 6 is a laminated core formed by laminating a number of thin plates made of a magnetic material, and the claw-shaped magnetic pole pieces 31 of the pole cores 31 and 32 are provided.
a, the magnetic flux coming out of 32a is a three-phase stator coil x,
It forms a magnetic flux path that is made to effectively intersect with y and z.

As shown in FIG. 3, slots 7 are formed in an annular shape at equal angular intervals on the inner peripheral side of the stator core 6, and T-shaped teeth (teeth) are provided between adjacent slots 7. 9 are formed. And the stator core 6
The number of slots per pole and phase is 0.5. The number of the teeth 9 is such that three teeth 9a to 9c are formed for every two magnetic pole pitches of the field poles formed by the rotor coils 33 inside the pole cores 31 and 32 facing the inner diameter side of the teeth 9, and the total number is 9 3 times teeth 9
Are formed in an annular shape.

The three-phase stator coils x, y, z are conductors made of copper wire, and the claw-shaped magnetic pole pieces 3 of the pole cores 31, 32 are formed.
The winding pitch is 2π / with respect to the magnetic pole pitch of 1a and 32a.
3 is a short-section winding type armature winding and a stator coil. The three-phase stator coils x, y, and z are Δ-connected or Y-connected. The three-phase stator coils x, y, and z are inserted into slots 7 between different teeth 9.

Then, the three-phase stator coils x, y, z
As shown in FIG. 1, FIG. 3, and FIG. 5, a plurality of coil portions (series conductors) 41 wound around each tooth 9 a plurality of times and two adjacent coils A crossover line 42 connecting the portions 41 is provided. As shown in FIG. 4, each of the plurality of coil portions 41 has a coil side 43 inserted into each slot 7,
Coil ends (coil ends) 44 and 2
Are provided with two coil sides 43 and two coil ends 44, respectively.

These three-phase stator coils x, y, z
Is wound around each of the teeth 9a to 9c by lap winding. In the slot 7, the stator coil x and the stator coil y, the stator coil y and the stator coil z, and the stator coil z and the stator coil x
Are dividedly distributed and wound.

The three-phase stator coils x, y,
The winding method of z is the 2π / 3 short section lap winding method,
The winding order of the three-phase stator coils x, y, and z is as follows. As shown in FIG. 5A, first, the first coil portion 41 of the X-phase stator coil x is wound around the teeth 9a, and then, as shown in FIG. Y
The first coil portion 41 of the phase stator coil y is wound around the teeth 9b next to the teeth 9a.

Thereafter, as shown in FIG.
After the first coil portion 41 of the phase stator coil z is wound around the tooth 9c next to the tooth 9b, the second coil portion 41 of the X-phase stator coil x is next to the tooth 9c. 5D, the X-phase stator coils x and the Y-phase stator coils 9a to 9c are arranged around the plurality of teeth 9a to 9c arranged in the circumferential direction as shown in FIG. The winding of the stator coil y and the Z-phase stator coil z is repeated.

[Operation of the first embodiment] Next, as in the present embodiment, a vehicle having a winding structure in which the winding pitch is 2π / 3 and the winding pitch is 2π / 3 with respect to the magnetic pole pitch of the pole cores 31 and 32. The operation of the AC generator 1 will be briefly described with reference to FIGS.

When the rotational power of the engine is transmitted to the poly V pulley 27 via the V belt, the shaft 3, that is, the rotor 4 rotates. When a voltage is applied to the rotor coil 33 from the outside and an exciting current flows through the rotor coil 33, the claw-shaped magnetic pole pieces 31a of the pole cores 31, 32,
32a is magnetized. That is, all of the claw-shaped magnetic pole pieces 31a of the pole core 31 become N poles, and all of the claw-shaped magnetic pole pieces 32a of the pole core 32 become S poles.

Then, a rotating magnetic field is generated in the stator core 6 of the stator 5 fixed to the outer peripheral side of the rotor 4, and an alternating current is induced in the three-phase stator coils x, y, z. The three-phase alternating current is converted into a direct current by the three-phase rectifier 20 to charge a battery and supply electric power to an electric device and an electric control device.

Further, with the rotation of the pole cores 31 and 32, the cooling fans 35 and 36 attached to both axial sides of the pole cores 31 and 32 also rotate integrally. Air inlet 15,
Cooling air is sucked in from 16, and cooling air is generated inside the vehicle alternator 1. Thus, the heat generating members such as the rotor coil 33, the three-phase rectifier 20, the voltage regulator 21, and the three-phase stator coils x, y, z, etc., which generate heat when energized, are cooled.

[Effects of the First Embodiment] As described above, the three-phase stator coils x, y, z
AC generator 1 provided with a stator 5 in which is wound in a short pitch of 2π / 3, has stator coils x, y, z of each phase.
Of the main coil ends 44 of the respective coil portions 41 are reduced.

Further, the stator coils x, y,
Since the crossovers 42 connecting the coil portions 41 of z are wound in the same direction in all three phases, the crossovers 42 do not stick (see FIG. 5), and the crossovers 42 are connected to the coil ends 44. Since it is possible to suppress the interference and prevent the coil portions 41 from being wound around the teeth 9, a coil length shorter than that of the conventional device can be easily achieved. Since the total length of the three-phase stator coils x, y, and z is reduced, the length of the copper wire required for the three-phase stator coils x, y, and z is reduced. The phase stator coils x, y, and z can be reduced in weight and cost.

In addition, since the stator core 6 having 0.5 slots per pole / phase is used, the number of windings of the stator coils x, y and z of each phase on the slot 7 is smaller than that of the conventional device. Since the number of windings of the former generator (the alternator for a vehicle provided with a stator having a slot number of 1.0 for each pole and each phase) is halved, the winding is further facilitated. The stator coils x, y,
The winding of z is easy.

According to the winding structure of the stator coils x, y and z, the ratio of the axial distance L of the coil portion 41 to the circumferential distance W of the coil portion 41 is larger than 1.0. 5 or when the number of magnetic poles of the pole cores 31 and 32 is P, the ratio of the axial distance L of the stator coils x, y, and z wound around the stator core 6 to the inner diameter D of the stator core 6 Is set to 0.1 or more and less than 4.7 / P, so that the decrease in the electromotive voltage due to the short winding can be covered by the reduction in the resistance value due to the shortening of the coil length of the coil section 41, so that the conventional device can be used. The power generation capacity can be made basically the same as that of a generator (a vehicle AC generator having a stator with a full winding that has a winding pitch equal to the magnetic pole pitch).

In addition, a gap L1 of unequal size is formed between the axial front end and the rear end of each of the coil portions 41 of the stator coils x, y, and z. Is a passage for the cooling air, and the cooling effect is increased by the larger exposed area of the cooling air for contacting the cooling air formed by the gap L1.

Further, three-phase stator coils x, y, z
The coil length in the circumferential direction of the coil portion 41 (circumferential distance W) can be shortened by winding the coil in a short pitch winding, so that the conductor length per one coil portion 41 is smaller than that of the conventional device. Since the machine is reduced from N · (W + L) to N · (β · W + L), the loss that occurs when the same load current flows is less than about 87% due to the relationship of (current I) ² · (resistance R). To decrease. Thereby, the three-phase stator coil x,
Since the amount of heat generation of y and z is reduced and the rate of temperature rise is reduced, the efficiency of the automotive alternator 1 is also improved, and the output is also increased. Here, N is the number of coil turns, and β is the ratio between the winding pitch and the magnetic pole pitch.

As described above, according to the AC generator 1 for a vehicle according to the present embodiment, the same winding can be performed with a coil having a shorter overall length than that of the conventional device, and the stator coil x,
Cooling is efficiently performed by increasing the exposed area of y, z, and furthermore, the two-phase coil portion 41 of the three-phase stator coils x, y, z is wrapped in the slot 7, and Since the winding leakage portion of the coil portion 41 is halved, the leakage reactance is halved, and a sharp rising output characteristic from low to medium to high speed is obtained. Further, the area ratio of the inner diameters of the stator coils x, y, and z to the field poles is increased, and the gap permeance is somewhat reduced to increase the magnetic flux, so that the output of the automotive alternator 1 in the low-speed rotation range is reduced. Increase.

[Second Embodiment] FIGS. 6 and 7 show a second embodiment of the present invention. FIG. 6 is a diagram showing a main part of a stator of an automotive alternator, and FIG. FIG. 3 is a diagram illustrating a winding structure of a three-phase stator coil.

On the inner periphery of the stator core 6 of this embodiment, six teeth 9 are formed at equal angular intervals for each two magnetic pole pitches of the pole cores 31 and 32 of the rotor. The three-phase stator coil (stator coil) 50 wound around each tooth 9 of the stator core 6 is a three-phase first stator coil wound by 2π / 3 short sections around each tooth 9 with respect to the magnetic pole pitch. A first connection in which Δa or Y connection is made to 51a to 51c
On the inner peripheral side of the three-phase connection coil 51 and the first three-phase connection coil 51, each tooth 9 has 2π /
Three-phase second stator coils 52a-
Second three-phase connection coil 5 in which 52c is Δ-connected or Y-connected
Consists of two.

The first stator coil 51a is wound around two adjacent teeth 9a and 9b, and then is wound around the teeth 9g and 9h which jump over the four teeth 9c to 9f following the tooth 9b. Wound. Further, the first stator coil 51b is wound around the teeth 9i and 9j which jump over the four teeth 9e to 9h after being wound around the two teeth 9c and 9d.

Further, similarly, the first stator coil 51c is wound around two teeth 9e and 9f in an overlapping manner and then jumps over the four teeth 9g to 9j.
k, wrapped around 9 l. The three-phase first stator coil 5 is sequentially repeated by repeating the above-described winding pattern.
1a to 51c are wound around each tooth 9 of the stator core 6.

The second stator coil 52a is wound with an electrical angle of π / 3 radian relative to the first stator coil 51a, that is, shifted by one tooth 9 in the winding direction. The second stator coil 52a is connected to two adjacent stator coils 52a.
After being wound around the teeth 9b and 9c
9h, 9 which jumped over 9d-9g
It is wound around i.

The second stator coils 52b, 52c
Are also shifted in the winding direction by an electrical angle of π / 3 radians with respect to the first stator coils 51b and 51c, that is, by one tooth 9, in a winding pattern similar to that of the second stator coil 52a. Each tooth 9 of the stator core 6 is sequentially wound.

As described above, the three-phase stator coil 50
According to the automotive alternator 1 incorporating the stator 5 wound in a two-layer winding, the three-phase stator coil 5
The second and fourth harmonics having large amplitudes included in the reaction magnetomotive force generated from 0 can cancel out the harmonics which have the 18th rotation fluctuation with respect to the rotation of the rotor 4, and 2π / 2 shown in the first embodiment. Compared to the case of a winding structure called three short-lap windings, the same sound level due to the generation of magnetic sound can be further reduced, and the output current of the vehicle alternator 1 is increased.
In addition, an increase in electromagnetic noise can be suppressed.

The first and second three-phase connection coils 51, 5
2 is a 2π / 3 short-section winding system, so that the winding pitch is equal to the magnetic pole pitch of the field poles. The winding length of the two stator coils 51a to 51c and 52a to 52c is short, and the first and second stator coils 51a to 51c,
The first and second three-phase connection coils 51 and 52 are reduced by reducing the overlapping portions where the 52a to 52c overlap.
And the exposed area of the cooling air contact surrounding the surface increases to increase the cooling efficiency.

[Modification] In this embodiment, the stator core 6
Although the stator 5 in which three-phase stator coils x, y, and z are wound on the inner peripheral side of the stator core is used, a stator in which two-phase stator coils are wound on the inner peripheral side of the stator core may be used. A stator wound with the above-described multi-phase stator coil may be used.

[Brief description of the drawings]

FIG. 1 is a developed view showing a winding structure of a three-phase stator coil (first embodiment).

FIG. 2 is a sectional view showing the overall structure of the vehicle alternator (first embodiment).

FIG. 3 is a schematic view showing a part of a winding state of a three-phase stator coil (first embodiment).

FIG. 4 is a developed external view showing a part of a winding state of a three-phase stator coil (first embodiment).

FIG. 5 is a process diagram showing a method of winding a three-phase stator coil (first embodiment).

FIG. 6 is a front view showing a main part of a stator of the automotive alternator (second embodiment).

FIG. 7 is a developed view showing a winding structure of a three-phase stator coil (second embodiment).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 AC generator for vehicle (AC generator) 3 Shaft 4 Rotor (rotor) 5 Stator (stator, armature) 6 Stator core 7 Slot 9 Teeth 31 Pole core (field pole) 32 Pole core (field pole) 35 Cooling fan 36 Cooling fan 41 Coil section 42 Crossover 43 Coil side 44 Coil end 51 First three-phase connection coil (first multiphase connection coil) 52 Second three-phase connection coil (second multiphase connection coil) 31a Claw-shaped magnetic pole piece 32a Claw-shaped magnetic pole pieces 51a to 51c First stator coil 52a to 52c Second stator coil x X-phase stator coil y Y-phase stator coil z Z-phase stator coil

Claims (3)

[Claims] 1. A rotor having a field pole, a stator core disposed opposite to an outer circumference of a field pole of the rotor and having a plurality of slots formed in an inner circumference, and wound around the stator core inserted into the slot. And a stator having a multi-phase stator coil, wherein the winding pitch of the multi-phase stator coil is 2π with respect to the magnetic pole pitch of the field pole.
In the alternator superimposed on a short-section winding of / 3, the one-phase stator coil of the multi-phase stator coil has a coil side inserted in the slot and an outer coil coil outside the plurality of slots. A plurality of coil portions each having a coil end and a plurality of crossover wires connecting two adjacent coil portions, wherein the coil is wound while sharing the same slot. And a method for manufacturing the same, wherein the parts are sequentially wound in an annular shape for each slot. 2. The alternator for a vehicle according to claim 1, wherein the stator core has 0.5 slots per pole and per phase. 3. The multi-phase stator coil according to claim 1, wherein said first stator coil is a multi-phase connection of a first stator coil wound in short pitch winding around teeth of said stator core with respect to a magnetic pole pitch of said field poles. A second fixed coil wound in two layers with a coil and a first stator coil of the first multi-phase connection coil shifted by an electrical angle of π / 3 radians with respect to each of the first stator coils, and wound in short teeth over the teeth of the stator core. The AC generator for a vehicle according to claim 1, wherein each of the first and second stator coils of the first multi-phase connection coil includes a second multi-phase connection coil connected in the same connection manner. Machine and its manufacturing method.