JP3428045B2 - AC generator for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator used in an alternator for charging a battery mounted on a vehicle.

[0002]

2. Description of the Related Art In recent years, a vehicle AC generator is desired to have a small size and a high output due to an increase in an electric load mounted on a vehicle and a narrowing of a mounting space for auxiliary machinery accompanying the downsizing of an engine room. ing. Therefore, it is conceivable to improve the cooling efficiency as one means for increasing the output of the vehicle alternator. As such a vehicle AC generator, there is a technique disclosed in, for example, Japanese Patent Laid-Open No. 3-226251. As shown in FIGS. 6 to 8, this technique has three teeth 101 to 103 in the circumferential direction for every two magnetic pole pitches of the rotor 100, and each of the teeth 101 to 103 has a three-phase stator coil. The stator core 10 is provided with the stator 107 in which only one of the phases 104 to 106 is wound.
By reducing the overlap margin in which the respective phases of the three-phase stator coils 104 to 106 housed in the eight slots 109 overlap with each other, the contact exposure area with the cooling air blown by the cooling fan (not shown) is reduced. The cooling efficiency of the three-phase stator coils 104 to 106 is increased (hereinafter referred to as a conventional technique).
Is proposed.

[0003]

However, in the prior art, the slot 109 of the stator core 108 has a semi-closed slot shape, and therefore the three-phase stator coil 10 is used.
It is necessary to insert each of the phases 4 to 106 in order from the back of the slot 109, and there is a problem that a great number of man-hours are required for winding the three-phase stator coils 104 to 106. In addition, since the radial overlap of each phase of the three-phase stator coils 104 to 106 inevitably occurs, the exposed area of each phase of the three-phase stator coils 104 to 106 decreases, and the three-phase stator coils 104 to 106 There is a problem that the cooling efficiency of 106 is lowered. Such a three-phase stator coil
Variations in heat dissipation and cooling are due to variations in resistance.
However, this causes variations in output, which is not desirable. Also in the core
The gap in the slot and each phase at the coil end
Overlapping of coils, presence or absence of each phase coil at coil end
Etc. leads to uneven shape of the inner surface of the stator
However, it is disadvantageous in terms of heat dissipation and noise. The present invention is polyphase
Improving cooling of the stator coil and suppressing noise
With the goal. The present invention has a uniform stator coil shape.
The purpose is to achieve The present invention further provides productivity
To improve.

[0004]

The present invention employs the following technical means in order to achieve the above object. In a vehicular alternator comprising a rotor, a stator arranged radially outside of the rotor, and a fan provided in the rotor for generating cooling air flowing radially outward, the stator comprises a plurality of slots. A core formed of a plurality of teeth, and a stator coil having a plurality of concentrated winding coils wound around a corresponding one of the plurality of teeth, each of the plurality of concentrated winding coils , They are arranged at the same radial position so as to be adjacent to each other on the circumference, and the adjacent concentrated winding coils are arranged so as to substantially fill the slots between the wound teeth. And the concentrated winding coil is the slot
Has a coil end portion that extends axially from
The coil end portion is radially outside the rotor and the fan.
A substantially continuous cylindrical inner surface facing and facing these
A technical means called a vehicle alternator characterized by forming a surface is adopted. The teeth of the multiple has three teeth per 2 pole pitch of said rotor,
It is possible to employ a technical means in which one of the concentrated winding coils is wound around only one of the three teeth. It is possible to employ a technical means that each of the plurality of teeth has a columnar portion around which the concentrated winding coil is wound, and an enlarged portion formed at the tip of the columnar portion on the radially inner side. It is possible to employ a technical means that the enlarged portion is formed in a T shape after the concentrated winding coil is mounted.

[0005]

In the present invention, the concentrated winding coils are adjacent to each other on the circumference.
Since they are arranged at the same radial position,
Each of the concentrated winding coils is exposed in the radial direction,
There is no unevenness such as not being exposed. Moreover, the slot
Since the concentrated winding coil is arranged to substantially fill the
There is no excessive gap between the concentrated winding coils. This allows
Improved cooling of the data coil and reduced noise are achieved.
It Further, it is possible to easily attach a plurality of concentrated winding coils.
Especially the shape of multiple concentrated winding coils that make up the stator coil
Since there is no unevenness in the shape, uniform cooling and noise reduction can be achieved.
It will be possible. Inside a cylindrical shape with a series of concentrated winding coils
Uniform and smooth coil end by forming the side surface
The shape of the rotor and fan.
The noise generated by the cooling air sent back is suppressed. Concentrated winding
One of the coils has three tees for every two pole pitches of the rotor.
According to the configuration that is wound only on one of the
2π / 3 short-pitch winding having the effect of reducing winding resistance by shortening
The line is obtained. Enlarged part at the radial inner tip
With this configuration, the concentrated winding coil is prevented from falling off or coming off.
It A structure in which the enlarged portion is formed after the concentrated winding coil is mounted
According to the above, productivity can be improved.

[0006]

EXAMPLES [Structure of Examples] Next, a vehicle AC generator of the present invention will be described based on an example shown in FIGS. 1 to 5. FIG. 1 is a diagram showing a stator of an automobile AC generator, and FIG. 2 is a diagram showing an entire structure of the automobile AC generator. The automotive alternator 1 is a so-called alternator and includes a rotor 2, a drive frame 3, a rear frame 4, a stator 5, and the like. The rotor 2 is a portion that acts as a field and rotates integrally with the shaft 6. The rotor 2 includes pole cores (magnetic poles) 7, 8,
The field coil 9 and the slip ring 10 are included.

A V-ribbed pulley 11 for transmitting the rotational power of the engine to the shaft 6 is provided at one end of the shaft 6.
Is attached. The V-ribbed pulley 11 is connected to the output shaft of the engine via a connecting means such as a belt. When the field coil 9 is wound around the center of the pole cores 7 and 8 and an exciting current flows through the field coil 9, all the claw-shaped portions 12 of the pole core 7 become N poles and all the claw-shaped portions 13 of the pole core 8 are S poles. become. Further, cooling fans 14 and 15 for sucking cooling air into the drive frame 3 and the rear frame 4 are integrally attached to the respective end surfaces of the pole cores 7 and 8. The cooling fan 14 is an axial flow fan that generates cooling air in the axial direction and the radial direction (centrifugal direction) of the shaft 6, and the cooling fan 15 is the cooling air in the radial direction (centrifugal direction) of the shaft 6. A centrifugal fan is used to generate the. Slip ring 1
Two 0 are attached to the other end of the shaft 6,
The brushes 16 slide on the outer circumference of each slip ring 10.

The drive frame 3 and the rear frame 4 are
The rotor 2 and the stator 5 are supported, and at the same time, they are attached to the engine, and a large number of holes 17 and 18 for ventilation of cooling air sucked by the cooling fans 14 and 15 are opened. The drive frame 3 and the rear frame 4 are directly joined by a plurality of stud bolts 19 and nuts 20. The rotor 2 is rotatably supported on the inner circumferences of the drive frame 3 and the rear frame 4 via bearings 21 and 22.

The rear frame 4 has brushes 16,
The rectifier 23, the output terminal, etc. are attached. Then, the rectifier 23, the brush holder 24, the IC regulator 25 and the like are attached to the rear side of the rear frame 4 by means of screws or the like. The rectifier 23 is a collection of a plurality of diodes (not shown) and converts (rectifies) an alternating current into a direct current. The rectifier 23 is electrically connected to an electric load and a battery mounted on the vehicle. The brush holder 24 stores and holds the brush 16. The IC regulator 25 controls the exciting current by turning on and off a switching element such as a transistor inserted between the field coil 9 and the ground to make the output voltage of the automotive alternator 1 constant.

Next, details of the structure of the stator 5 will be described with reference to FIGS. The stator 5 is a so-called 2 /
3π short-section concentrated winding stator with pole cores 7 and 8
The stator core 26 is arranged to face the outer circumference of the rotor, and the three-phase stator coils 27 to 29 induce a three-phase AC output as the rotor 2 rotates. Stator core 26
Is integrated by being press-fitted into the inner circumferences of the drive frame 3 and the rear frame 4, so that the heat generated in the stator 5 is transferred to the drive frame 3 and the rear frame 4 to improve the cooling performance.

The stator core 26 is formed by laminating a plurality of thin plates made of a magnetic material, and comprises the pole core 7 of the rotor 2,
The magnetic flux from 8 forms a magnetic flux path made so as to effectively intersect the three-phase stator coils 27 to 29. On the inner peripheral side of the stator core 26, as shown in FIG. 1, a large number of three teeth 30 to 32 are formed at equal intervals in the circumferential direction with respect to the two magnetic pole pitches of the pole cores 7 and 8 of the rotor 2. The slots 33 formed between the adjacent teeth 30 to 32 are formed so as to have an open slot shape (shown by a solid line in FIG. 3) when the three-phase stator coils 27 to 29 are wound. After winding the phase stator coils 27 to 29, the stator coils 27 to 29 are formed to have a semi-closed slot shape (shown by a chain double-dashed line in FIG. 3).

The teeth 30 are formed every two pieces.
Among the three-phase stator coils 27 to 29, only one-phase stator coil 27 is wound around. Further, only the one-phase stator coil 28 of the three-phase stator coils 27 to 29 is wound around the teeth 31 formed every two pieces. Further, only the one-phase stator coil 29 of the three-phase stator coils 27 to 29 is wound around the teeth 32 formed every two pieces. The three-phase stator coils 27 to 29 are connected by Y connection or Δ connection.

Next, the three-phase stator coils 27-2
The winding method of No. 9 will be briefly described with reference to FIGS. The tips of the teeth 30 to 32 are key-shaped when the three-phase stator coils 27 to 29 are wound, as shown in FIG. As shown in FIG. 4, the stator coil 27 is heavily wound around the tooth 30 of the stator core 26, and then the adjacent teeth 31 and 32 are placed and wound around the next tooth 30. . Similarly, the winding of the stator coil 27 is repeated only around the teeth 30 of the stator core 26,
The stator coil 27 is attached to the stator core 26.

Further, as shown in FIG. 4, the stator coil 28 starts to be wound from the teeth 31 of the stator core 26, and like the stator coil 27, the teeth 32 and 30.
The stator coil 28 is assembled to the stator core 26 by repeating the winding of the stator coil 28. Further, as shown in FIG. 4, the stator coil 29 has the stator core 2
The stator coil 29 is assembled to the stator core 26 by starting winding from the tooth 32 of No. 6 and repeating the winding with the teeth 30 and 31 like the stator coil 27.

Since the tips of the teeth 30 to 32 of the stator core 26 do not spread when the three-phase stator coils 27 to 29 are wound, that is, the slot 33 does not have a semi-closed slot shape, the configuration of FIG. As shown in FIG. 3, the boundary lines between the three-phase stator coils 27 to 29 are wound around each of the teeth 30 to 32 so as to extend in the radial direction of the stator core 26. The phases 27 to 29 do not overlap each other in the radial direction. Then, after the winding of the three-phase stator coils 27 to 29 is completed, the tips of the teeth 30 to 32 are expanded in the circumferential direction to form the teeth 30 to 32 in a T shape, thereby reducing the magnetic flux of the stator 5. Is being prevented.

Therefore, the three-phase stator coil 2 is previously prepared.
Before assembling each phase 7 to 29 to the stator core 26,
It is wound so as to be in the winding state shown in FIG. 3 (hold coil state), and each phase of the three-phase stator coils 27 to 29 wound in this way is opened at the same time. By inserting into the stator core 33, the three phases of the three-phase stator coils 27 to 29 are simultaneously formed.
6 can be easily assembled, so that the three-phase stator coil 27
It is possible to remarkably reduce the number of assembling steps for winding 29 to 29. In addition, a gap S having a uniform size is formed between the front coil ends 34 to 36 and the rear coil ends (not shown) of the three-phase stator coils 27 to 29. By forming these gaps S, a large number of gaps S serve as ventilation passages for passing cooling air, and the cooling efficiency of the three-phase stator coils 27 to 29 is improved.

[Operation of the Embodiment] Next, the operation of the automotive AC generator 1 will be briefly described with reference to FIGS. 1 to 5. When the rotational power of the engine is transmitted to the V-ribbed pulley 11 via the belt, the rotor 2, that is, the shaft 6 rotates. Then, when a voltage is applied to the field coil 9 from the outside and an exciting current flows through the field coil 9, the pole cores 7 and 8 are excited. As a result, all the claw-shaped portions 12 of the pole core 7 become the N pole and all the claw-shaped portions 13 of the pole core 8 become the S pole. Then, the stator core 26 of the stator 5 that rotates relative to the rotor 2
A rotating magnetic field is generated in the direction of the arrow shown in FIG. 1, and an alternating current is induced in the three-phase stator coils 27 to 29. This three-phase alternating current is converted into a direct current by the rectifier 23 to charge the battery and supply electric power to the electric load of the vehicle.

Further, as the pole cores 7 and 8 rotate, the cooling fans 14 and 15 attached to the end faces of the pole cores 7 and 8 also rotate, so that they are formed in the drive frame 3 and the rear frame 4. Ventilation hole 1
Cooling air is sucked from 7, 18 to generate cooling air in the automobile AC generator 1 in the direction of the arrow shown in FIG. 2, and the field coil 9, the rectifier 23, and the three-phase stator coil 2 are generated.
The heat generating members such as 7 to 29 are cooled.

[Effects of the Embodiment] As described above, in this embodiment, the winding structure of the three-phase stator coils 27 to 29 is such that the boundary line between each phase of the three-phase stator coils 27 to 29 is the stator core. Since it is wound around each of the plurality of teeth 30 to 32 so as to extend in the radial direction of 26, there is no radial overlap between the respective phases of the three-phase stator coils 27 to 29. Therefore, the three-phase stator coil 27
Since each phase of ~ 29 can be uniformly cooled, the cooling efficiency of the three-phase stator coils 27-29 can be remarkably improved. Further, as is clear from comparison between FIG. 5 and FIG. 8, the gap S formed at the front coil ends 34 to 36 and the rear coil ends of the three-phase stator coils 27 to 29.
Is increased and the passage of cooling air is improved. This increases the overall cooling air volume, so that the field coils 9 other than the three-phase stator coils 27 to 29,
It is also possible to improve the cooling efficiency of the heat generating members such as the rectifier 23 and the three-phase stator coils 27 to 29.

Since only one phase of the three-phase stator coils 27-29 is wound around each of the plurality of teeth 30-32, the three-phase stator coils 27-29 are wound. The coil length of each phase can be shortened. As a result, the three-phase stator coils 27 to 29
Since the coil resistance value of each phase is reduced, the heat generation amount of each phase of the three-phase stator coils 27 to 29 can be reduced. Further, when winding the three-phase stator coils 27 to 29, it is possible to simultaneously assemble the three-phase stator coils 27 to 29 into the stator core 26, so that the three-phase stator coils 27 to 29 are wound. It is possible to significantly reduce the number of assembling steps.

[Modification] In the present embodiment, the present invention is applied to the three-phase stator coils 27 to 29, but it may be applied to a two-phase stator coil or four-phase or more stator coils. In this embodiment, the teeth 30 of the stator core 26 are
Three 32 are provided at equal intervals for the two magnetic pole pitches of the pole cores 7 and 8, but the present invention is not limited to this example. In this embodiment, the present invention is used for a normal alternator, but the present invention may be used for a vehicle AC generator such as a brushless alternator or an alternator with a vacuum pump.

[0022]

According to the structure of the present invention , each phase of the three-phase stator coil can be cooled substantially uniformly, and noise can be reduced. Also, the concentrated winding coil is actually
By forming a qualitatively continuous cylindrical inner surface, it can be
Can provide one smooth coil end shape,
Caused by cooling air sent by rotor and fan
Noise can be suppressed. According to the configuration of the present invention,
2π with the effect of reducing winding resistance by shortening the coil length
/ 3 short-pitch winding can be obtained. Also, concentrated winding coil
Can be prevented from falling off. Also, improve productivity
be able to.

[Brief description of drawings]

FIG. 1 is a front view showing a main part of an automotive alternator using the present invention.

FIG. 2 is a cross-sectional view showing the overall structure of the automobile AC generator of FIG.

3 is a schematic view showing a winding state of a stator coil of the automobile AC generator of FIG. 1. FIG.

FIG. 4 is a schematic development view showing a winding state of a stator coil of the automobile AC generator of FIG.

5 is a schematic diagram showing a front coil end of a stator coil of the automobile AC generator of FIG. 1. FIG.

FIG. 6 is a sectional view showing a main part of a conventional technique.

FIG. 7 is a schematic view showing a winding state of a conventional stator coil.

FIG. 8 is a schematic development view showing a winding state of the stator coil shown in FIG.

[Explanation of symbols]

1 Car AC generator (alternator) 2 rotor 5 Stator 7 pole core 8 pole core 14 Cooling fan 15 Cooling fan 17 Ventilation holes 18 Ventilation holes 26 Stator core 27 Stator coil 28 Stator coil 29 Stator coil 30 Teeth 31 Teeth 32 Teeth 33 slots

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Claims (4)

(57) [Claims] 1. An automotive alternator comprising a rotor, a stator arranged radially outside the rotor, and a fan provided in the rotor for generating cooling air flowing radially outward, wherein the stator is A core having a plurality of slots and a plurality of teeth, and a stator coil having a plurality of concentrated winding coils wound around a corresponding one of the plurality of teeth. Each of the wound coils is arranged at the same radial position such that they are adjacent to each other on the circumference, and the adjacent concentrated wound coils substantially define the slots between the wound teeth. filled are arranged, the concentrated winding coils, extend out axially from the slot
Has a coil end portion, and the coil end portion is
Located on the outer side of the rotor and the fan in the radial direction
An alternating current generator for a vehicle, which is characterized by forming a substantially continuous cylindrical inner surface facing the vehicle. 2. A plurality of the teeth are two of the rotor.
The concentrated winding coil has three teeth per magnetic pole pitch.
The vehicle alternator according to claim 1, wherein one of the wheels is wound around only one of the three teeth . 3. A plurality of the teeth are the concentrated winding carp.
The columnar part around which the roll is wound and the inside in the radial direction of the columnar part
The vehicle alternator according to claim 1 or 2, further comprising an enlarged portion formed at a tip . 4. The concentrated winding coil is mounted on the enlarged portion.
Vehicle AC generator according to claim 3, wherein a T-shaped der Rukoto formed after wearing.