JPH1175347A - Alternating current generator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the output along with reducing noise, by supplying a cooling wind having a larger quantity or faster velocity, to a first group of coil ends formed at one end area of a stator core, than a second group of coil ends provided at the other end area. SOLUTION: In the end area of the disk 72 of a Randel type pole core 7, a mixed flow fan 11 and a centrifugal fan 12 are provided for cooling. Here, both the projection area and the outer diameter of the blades of the mixed flow fan 11 are set smaller than those of the blades of the centrifugal fan 12. At the time of operation, a group of coil ends 31d is cooled by the mixed flow fan 11, and a group of coil ends 31c is cooled by the centrifugal fan 12. And the quantity of a cooling wind supplied by the mixed flow fan 11 is smaller than that of a cooling wind supplied by the centrifugal fan 12. Consequently, it becomes possible to reduce the interference sound of the group 31d of coil ends. Besides, it is possible to perform cooling efficiently even by a smaller amount of cooling wind, since the group 31d of coil ends is on the side of a pulley 20, and an ambient air temperature is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator driven by an internal combustion engine, and more particularly to an alternator for a vehicle which can be mounted on a vehicle such as a passenger car, a truck or a ship.

[0002]

2. Description of the Related Art In recent years, there has been a demand for an increase in an electric load of a safety control device and the like, and an improvement in power generation capacity has been increasingly demanded. In addition, engine noise has been increasingly reduced in recent years due to social demands for reducing noise outside the vehicle and the aim of improving productivity by improving the quietness of the vehicle interior. Fan noise is becoming annoying.

[0003] The fan noise of the AC generator is caused by the collision between the coil end and the wind by the cooling fan. The interference sound is conspicuously formed by unevenness formed on the inner peripheral portion of the coil end of the stator winding. Conventionally, in order to meet the requirements of high output or low noise as described above,
Various improvements have been proposed.

Japanese Patent Application Laid-Open No. 59-159638 discloses that a cooling fan is disposed in a frame, a coil end formed of a continuous linear conductor is formed in a flat shape, and a surface area to be exposed to cooling air is increased to improve cooling performance. It is known that the output is improved by improving the output. In addition, WO92 / 06527
In U.S. Pat. Nos. 5,739,898, a U-shaped electric conductor is inserted into a plurality of slots provided in a stator core from the same direction, and these are joined to form a stator winding. In this configuration, since the U-shaped electric conductors can be regularly arranged, it is easy to increase the space factor of the electric conductors in the slot, and it is possible to increase the output. Also, the winding operation is facilitated by inserting the U-shaped electric conductor from the same direction.

[0005]

However, in the coil end group of the stator winding in which the continuous linear conductor is wound, the interference in the circumferential direction of the winding of each phase is not eliminated structurally.
An uneven surface is formed on the inner peripheral portion. Therefore, fan noise still occurs when the cooling air collides with the uneven surface.

[0006] In WO92 / 06527,
A U-shaped electric conductor is inserted into the slot, and its end is joined by welding or the like. In the coil end where the U-shaped turn portion is arranged, the electric conductor may be bent to form a smooth cooling air passage. However, at the joint, the ends of the two electric conductors are joined. Therefore, at the coil end on the joint side, the joint becomes a wall that collides against the cooling air, and it is difficult to form a smooth ventilation path. Also,
No consideration is given to cooling corresponding to the different coil end shapes, and the requirement for fan noise reduction is not satisfied.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a vehicular alternator that has both high output and low noise requirements.

[0008]

In order to achieve the above object, a multi-phase stator winding is formed by arranging a plurality of turns of an electric conductor at one end of a stator core. A coil end group; and a second coil end group formed by arranging a plurality of joints of electric conductors at the other end of the stator core. The first coil end group includes a second coil end group. Technical means is used in which there is provided a blowing means for supplying a cooling air more or faster than the end group.

Since the ends of the two electric conductors are joined to each other at the coil end on the joint portion side, the joint portion is more likely to become a collision wall of the cooling air than the turn portion side. However, since the amount of cooling air supplied to the coil end group on the joining portion side is smaller than that of the coil end on the turn portion side or the speed of the cooling air is reduced, fan noise can be reduced.

[0010] It is preferable that the blowing means includes a first blowing fan corresponding to the first coil end group and a second blowing fan corresponding to the second coil end group. The first blower fan is provided at an axial end of the rotor corresponding to the first coil end group, and the second blower fan is provided at an axial end of the rotor facing the second coil end group. Is desirably provided.

[0011] The blower means includes a first blower fan and a second blower fan. In particular, by providing the blower fan at an axial end of the rotor corresponding to the coil end group, the first blower fan is provided.
Also, it is easy to make a difference in the amount of cooling air supplied to the second coil end group. It is desirable to use a technical means that the outer diameter of the first blower fan is larger than the outer diameter of the second blower fan. Further, it is desirable that the blade projected area of the first blower fan is larger than the blade projected area of the second blower fan. Further, it is desirable that the first blower fan is a centrifugal fan and the second blower fan is a mixed flow fan.

The amount of cooling air supplied by the blower fan increases as the outer diameter of the blower fan increases and the projected area of the blade of the blower fan increases. The centrifugal fan supplies the cooling air in the centrifugal direction, while the mixed flow fan can supply the cooling air dispersed in the centrifugal direction and the axial direction. Therefore, by using these means, it is possible to supply different amounts of cooling air to the first and second coil end groups.

It is desirable that the distance between the first blower fan and the first coil end group is shorter than the distance between the second blower fan and the second coil end group. The noise generated when cooling the stator windings is caused not only by the amount of cooling air supplied but also by the speed of the cooling air colliding with the coil end group. By making the distance between the second blower fan and the second coil end group relatively longer than the distance between the first blower fan and the first coil end group, the second coil end group in which a collision wall easily occurs. The speed of the cooling air to the air can be suppressed. Thereby, noise can also be reduced.

In order to achieve the above object, the multi-phase stator winding has a first coil end formed by arranging a plurality of turns of an electric conductor at one end of a stator core. And a second coil end group formed by arranging a plurality of joints of electric conductors at the other end of the stator core, and a first coil end group formed by the turn portions of the stator winding. And a second coil end group formed by the joints is provided with a blower for supplying cooling air in a different manner.

The first and second coil end groups have different shapes. However, by supplying the cooling air in a form corresponding to the different shape, noise due to the cooling air can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle alternator according to the present invention will be described below with reference to the embodiment shown in FIGS. The vehicular AC generator 1 includes a stator 2, a rotor 3, a frame 4 supporting the stator 2 and the rotor 3, a rectifier 5 for converting AC power to DC power, and the like.

The rotor 3 rotates integrally with the shaft 6, and includes a rundle type pole core 7, a field coil 8, slip rings 9 and 10, and a mixed flow fan 11 for cooling.
And a centrifugal fan 12 and the like. The shaft 6 is connected to a pulley 20 and is rotationally driven by a traveling engine (not shown) mounted on an automobile.
The Landel type pole core 7 is configured by combining a pair of pole cores. The pole cores are
And a plurality of claw-shaped magnetic pole portions 7 extending radially from both ends of the boss portion 71 and both ends of the boss portion 71
3. The field coil 8 is in contact with the inner surface of the claw-shaped magnetic pole 73 with an appropriate compressive force via the insulating paper 81. As the insulating paper 81, a sheet-shaped resin-impregnated sheet is used, and the field coil 8 is fixed by heat treatment, and the pole core 7 and the field coil 8 are insulated.

Disk portion 72 of Rundel-type pole core 7
Are provided with a mixed flow fan 11 and a centrifugal fan 12 for cooling, respectively. The projected area of the blade of the mixed flow fan 11 (the area of the blade projected in the rotation direction R) is set smaller than the projected area of the blade of the centrifugal fan 12. The outer diameter of the mixed flow fan 11 is set smaller than the outer diameter of the centrifugal fan 12. That is,
Mixed flow fan 11 and corresponding coil end group 31d
Is set to be longer than the distance between the centrifugal fan 12 and the corresponding coil end group 31c. The frame 4 has a cooling air discharge hole 42 at a portion facing the coil end group 31 of the stator 2 and a suction hole 41 at an axial end surface.

The stator 2 includes a stator core 32, a conductor segment 33 as an electric conductor constituting a stator winding, and an insulator 34 for electrically insulating the stator core 32 and the conductor segment 33 from each other. It is supported by the frame 4. The stator core 32 is formed by laminating thin steel plates, and has a large number of slots 35 formed on the inner peripheral surface thereof.

In the stator winding, a U-shaped conductor segment 33 made of a copper wire having a rectangular cross section shown in FIG. 3 is inserted into a slot 35, and the end of the conductor segment 33 is connected to another inserted conductor. It is constituted by joining to the end of the segment 33. A substantially identical U-shaped conductor segment 33 composed of an inner conductor 33a, an outer conductor 33b, a turn 33c, a joint 33d, and skewings 33e and 33f shown in FIG. The turn portions 33c are overlapped on the same side of the axial side surface of the iron core 32 so that the outer layer side conductor portion 33b is located on the back side of the slot and the inner layer side conductor portion 33a is located on the slot opening side as shown in FIG. Is inserted into. The conductor segments 33 are formed by bending a copper flat plate and pressing into a substantially U-shaped shape by pressing or the like. Press-fit. Thereafter, as shown in FIG. 2, the turn portion 33c and the skewing portion 33f.
After the joining portion 33d located on the side opposite to the first coil end group 31c formed by the above is bent in the circumferential direction opposite to each other, the other ends of the other conductor segments of the different layer are electrically connected to each other. They are joined by sonic welding, arc welding, brazing, or the like, and a second coil end group 31d is formed by the joining portion 33d and the oblique portion 33e. In addition,
FIG. 4 shows an example in which the conductor segment 33 has no insulating film, and the insulator 34 has an S-shape in order to insulate between electric conductors in the same slot.

As shown in FIG. 2, the stator core 32 is arranged so that one of its axial side surfaces is a turn portion 33c and the other is a joint portion 33d. Also, the conductor segment 33
The coil end skewing portions 33e and 33f are inclined in opposite directions in the outer layer and the inner layer, and are inclined in the same direction in each layer, so that a multi-phase stator winding can be arranged without interference. Then, the first coil end group 31c is formed by the turn portion 33c and the skew portion 33f, and the joint portion 33d and the skew portion 33e are formed.
Thus, a second coil end group 31d is formed. The stator 2 is supported by the frame 4 such that the second coil end group 31d is located on the pulley 20 side (front side) and the first coil end group 31c is located on the rear side. The conductor segment 33 may or may not have an insulating film.

When the vehicle alternator 1 operates, the centrifugal fan 12 rotates together with the rotor 3 and supplies air taken in from the suction hole 41 in the centrifugal direction. Then, the air is supplied to the coil end group 31c, and the coil end group 31c
And is discharged to the outside of the frame 4 through the discharge holes 42. On the other hand, the mixed flow fan 11 distributes the air taken in from the suction hole 41 in both the centrifugal direction and the axial direction.
The air distributed in the centrifugal direction is supplied to the coil end group 31d, and after cooling the coil end group 31d,
It is further discharged outside the frame 4. The air distributed in the axial direction cools the field coil 8, and then passes through the coil end group 31 c and is discharged to the outside of the frame 4 through the discharge holes 42.

The supply amount of cooling air in the centrifugal direction of the fan is
The larger the outer diameter of the fan and the larger the projected area of the fan blade, the larger the value. As described above, the outer diameter of the centrifugal fan 12 is set to be larger than the outer diameter of the mixed flow fan 11. The blade projection area of the centrifugal fan 12 is set larger than the blade projection area of the mixed flow fan 11. Therefore, the amount of cooling air supplied to the coil end group 31d by the mixed flow fan 11 is smaller than the amount of cooling air supplied to the coil end group 31c by the centrifugal fan 12.

FIG. 6 shows the turn of the conductor segment 33 as viewed from the arrow V in FIG. FIG. 7 shows the junction of the conductor segments 33 as viewed from the arrow VI in FIG. On the turn part 33c side (FIG. 6), the cooling air flows according to the inclination of the turn part 33c. However, on the side of the joint 33d (FIG. 7), the cooling air collides with the wall generated at the joint 33d of the rectangular segment. For this reason,
When the cooling air having the same air volume and the same speed is supplied, the interference sound due to the cooling air on the joint portion 33d side becomes larger than that on the turn portion 33c side.

However, as described above, the amount of cooling air supplied to the coil end group 31d is smaller than the amount of cooling air supplied to the coil end group 31c. In addition, coil end group 3
The speed of the cooling air to 1d is lower than the speed of the cooling air to the coil end group 31c. For this reason, the coil end group 31
The interference sound of d can be reduced. As shown in FIG. 5, since a gap is provided between the adjacent ridge portions 33 e of the coil end group 31, the cooling air can pass between them, and the coil end group 31 can be efficiently cooled. Can be. In general, the air temperature around the pulley 20 (front side) is lower than that at the rear side. Therefore,
The coil end group 31d can be efficiently cooled with a small amount of cooling air.

In this embodiment, the cooling fan has different shapes, outer diameters, blade projection areas, and distances from the coil ends between the front side and the rear side. However, the coil end group 31d due to the cooling air described above
In order to obtain the effect of reducing the interference sound, it is not always necessary to provide a difference in all of them. That is, by appropriately selecting some of these elements, the coil end group 3
The cooling air supply to 1d is made smaller than the cooling air supply to the coil end group 31c, or the coil end group 3
What is necessary is just to make the speed of the cooling air to 1d smaller than the speed of the cooling air to the coil end group 31c.

Further, in this embodiment, the cooling fan is provided at the axial end of the pole core 7, but the position of the cooling fan is not limited to this. To supply air into the frame 4. Thus, both coil end groups 3
By supplying the cooling air in a mode corresponding to the difference between the shapes 1c and 31d, the cooling noise can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an automotive alternator according to a first embodiment of the present invention.

FIG. 2 is an external view of a stator according to the first embodiment.

FIG. 3 is a perspective view of a conductor segment of the first embodiment.

FIG. 4 is a partial cross-sectional view of the stator according to the first embodiment.

FIG. 5 is a perspective view showing coil ends on both side surfaces of the stator according to the first embodiment.

6 is a view taken in the direction of arrow V in FIG. 5;

FIG. 7 is a view taken in the direction of the arrow VI in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Stator 3 Rotor 4 Frame 6 Shaft 7 Pole core 8 Field coil 9, 10 Slip ring 11 Mixed flow fan 12 Axial fan 31 Coil end 32 Stator core 33 Conductor segment 34 Insulator

Claims (8)

[Claims] 1. A field rotor which alternately forms NS poles along a circumferential direction of rotation, a stator core opposed to the rotor, and a multi-phase stator winding mounted on the stator core. In a vehicle alternator having a stator and a frame supporting the rotor and the stator, the multi-phase stator winding has an electric conductor at one end of the stator core. A first coil end group formed by arranging a plurality of turn portions and a second coil end group formed by arranging a plurality of joint portions of electric conductors at the other end of the stator core. An alternator for a vehicle, comprising: a blower that supplies more or faster cooling air to the first coil end group than to the second coil end group. 2. The air blower includes a first blower fan corresponding to the first coil end group and a second blower fan corresponding to the second coil end group. 2. The vehicle alternator according to 1. 3. The first blower fan is provided at an axial end of the rotor corresponding to the first coil end group, and the second blower fan corresponds to the second coil end group. 3. The vehicle alternator according to claim 2, wherein the generator is provided at an axial end of the rotor. 4. An outer diameter of said first blower fan is equal to said second fan.
The vehicle alternator according to claim 3, wherein the outside diameter of the blower fan is larger than the outside diameter of the blower fan. 5. The vehicle AC power generator according to claim 3, wherein a blade projected area of the first blower fan is larger than a blade projected area of the second blower fan. Machine. 6. The vehicle AC according to claim 3, wherein the first blower fan is a centrifugal fan, and the second blower fan is a mixed flow fan. Generator. 7. A distance between the first blower fan and the first coil end group is equal to a distance between the second blower fan and the second coil end group.
The vehicle alternator according to any one of claims 3 to 6, wherein the distance is shorter than a distance from the coil end group. 8. A field rotor which alternately forms NS poles along a circumferential direction of rotation, a stator core arranged opposite to the rotor, and a multi-phase stator winding mounted on the stator core. In a vehicle alternator having a stator and a frame supporting the rotor and the stator, the multi-phase stator winding has an electric conductor at one end of the stator core. A first coil end group formed by arranging a plurality of turn portions and a second coil end group formed by arranging a plurality of joint portions of electric conductors at the other end of the stator core. And a blower that supplies cooling air to the first coil end group formed by the turn portion of the stator winding and the second coil end group formed by the joint portion in a different manner. An alternator for a vehicle, comprising: