KR100289240B1 - Automotive Alternator - Google Patents

Abstract

It is an object of the present invention to provide a compact, high power vehicle alternator. Another object of the present invention is to provide a low noise alternator for a vehicle capable of outputting increased power during operation at low rotational speeds. The vehicle alternator 1 comprises a stator 2 having an inner circumferential surface with many slots having an open end 35. The teeth of the breaker between the slots have a flux collection protrusion 36 extending circumferentially. The magnetic flux collecting protrusions 36 are made in advance by the pressing process during the stages in which they are thin steel ends. The conductor forming the winding 33 has a diameter larger than the width of the inner openings of the slots. A portion of the conductor extends from the first side of the iron core 32 to the first slot and from the second side of the iron core 32 into a second slot away from the first slot at an electrical angle of 180 ° and It also extends from the first slot to the second side of the iron core 32 before extending from the second slot to the first side of the iron core 32. The winding 33 has a circulation of such parts forming one phase. For example, winding 33 has three phases separated by an electrical angle of 120 °.

Description

Automotive Alternator

The present invention relates to an alternator for a vehicle such as a passenger differential or truck.

In order to reduce aerodynamic resistance in driving conditions, the car body tends to be inclined nose form. There is a serious need to ensure sufficient housing for passenger boarding. In order to meet these requirements, the engine room of the vehicle has become increasingly narrow and compact in recent years, and only a limited space can be used for the space for installing the alternator. In addition, the temperature in the area near the alternator has increased. On the other hand, in order to improve fuel economy, the rotating engine speed tends to decrease gradually during idle. On the other hand, it is necessary to increase the electric load on safety control devices and the like. Therefore, the power generating capability of the alternator is greatly needed. In other words, a compact, high power automotive alternator is needed. In addition, inexpensive automotive alternators are preferred. In particular, it is desirable for the alternator to have good power generation performance when the alternator is operated at low rotational speeds.

In addition, there is a social demand that noises leaking from the vehicle must be removed. Providing a quiet passenger compartment increases product appeal. To this end, engine noise has been lowered in recent years. On the other hand, automotive alternators operating at high rotational speeds tend to produce annoying fan noise, windshield noise and magnetic noise.

In a typical automotive alternator, the largest heat source is the stator. In order to obtain the high output and high efficiency of the alternator, it is conceivable to reduce the heat loss by reducing the resistance of the winding on the stator. In particular, electrical conductors having a large cross-sectional area are used for the windings. In addition, it is conceivable to increase the ratio of the footprint of the conductor in each slot in the stator to the unoccupied area. This ratio is hereinafter referred to as the space coefficient.

In the prior art automotive alternator, the stator has an inner circumferential surface facing the rotor and in which teeth are formed. The tip of the tooth has a flux collection protrusion extending circumferentially. Thus, the open ends of the slots in the inner core of the stator are smaller in width than the inside of the slots. The thickness of the winding conductor is limited by the width of the open end of each slot. In order to increase the output of the prior art alternator while operating at low rotational speeds, a large length flux collecting protrusion is required. As the length of the flux collection protrusion increases, the open ends of the slots become narrower, requiring a thinner conductor for the winding. Thin conductors increase the resistance of the windings.

Unexamined Japanese Patent Application Laid-Open No. 63-194543 describes that the winding conductor is positioned in the slots, and these portions are made in advance in a shape having an almost rectangular cross section as shown in FIG. Some of the conductors are located in the slots as shown in Fig. 11 (a). Then, the edge of the stator around the slots is deformed into a magnetic flux collecting protrusion as shown in Fig. 11 (b).

In the prior art structure of Japanese application 63-194543, the plastic deformation to make the flux collecting protrusions lowers its magnetic properties. Thus, the flux collection effect is reduced. Therefore, it is difficult to obtain a desirable alternator output. In particular, it is difficult to provide increased alternator output during operation at low rotational speeds.

In the prior art structure of Japanese application 63-194543, the plastic deformation causes the strain of the stator to decrease the circularity of the inner circumferential surface of the stator, thereby forming an uneven air gap between the stator and the rotor. do. Uneven air gaps increase magnetic noise during operation of the prior art structures.

In view of the problems mentioned above, it is an object of the present invention to provide a compact high power automotive alternator.

Another object of the present invention is to provide a low noise alternator for a vehicle that outputs increased power during operation at low rotational speeds.

The invention of claim 1 is a rotor; A stator located outside the rotor and facing the rotor; And a frame supporting the rotor and the stator, the stator comprising an iron core and a plurality of conductors, the iron core having a plurality of slots, the conductors being the slots. Located within, the slots have openings, the openings having a width less than the width between the inner walls defining the slots, the width of the openings of the slots being less than the minimum width of the conductor.

This reduces the resistance of the conductors and reduces heat loss during power generation operation. Therefore, a high alternator output can be obtained. Since the protrusions of the corners of the stator teeth, which serve to collect the magnetic flux, are relatively long if the winding diameters are the same, the inner circumferential surface of the stator iron core can be close to a smooth cylindrical surface. Thus, it is possible to reduce the ruggedness of the inner surface of the stator iron core and also the wind noise caused by the radially outward wind caused by the LUNDEL-type pole core during the rotation of the rotor.

In the invention of claim 2, slots have two end surfaces in the axial direction of the iron core of the stator in which end surface openings are formed as inlets for the conductors. Thus, the width of the opening on the slot inner circumferential side can be set without being limited by the width of the conductor.

In the invention of claim 3, the openings in the slots are narrower than the width of the conductor receiving portion of the slots and also narrower than the minimum width of the conductors before the conductors are located in the slots. Thus, there is no need to deform the iron core tooth edges between the slots after the conductors are located in the slots.

Thereby, the protrusions of the tooth edges of the stator iron core, which serve to collect the magnetic flux, can be made into a desired shape without being formed by the molding deformation. Thus, deterioration of the magnetic properties of the material of the magnetic flux collecting protrusion can be prevented and a sufficient magnetic flux collecting effect can be obtained. Thus, the output at low speed is improved. Since there is no shape distortion of the tooth edges by the plastic deformation, the true circuit of the inner circumferential surface of the stator iron core is well maintained. Thus, the air gap between the stator and the magnetic pole can be made uniform. Thereby, it is possible to suppress magnetic noise due to nonuniformity of the air gap during power generation.

According to the invention mentioned in claim 4, the conductors can use conductors having a circular cross section larger in diameter than the width of the openings of the slots.

In the invention of claim 5, the cooling fan is installed at at least one shaft end of the rotor facing the stator. Thus, the wind is led from the cooling fan to the coil end of the stator winding protruding at the axial end of the stator iron core, whereby high cooling performance can be obtained. Thus, according to the structure of the present invention where the width of the inner circumferential openings of the slots of the stator is narrow, it is possible to cool the stator windings even if the axial groove-like wind path provided by the slots of the stator is narrow. Proper cooling wind is maintained.

In the invention of claim 6, cooling fans are provided at both shaft ends of the rotor facing the stator. Thus, cooling performance can be further increased and higher output can be achieved.

In the invention of claim 7, the distal surface of the stator in the axial direction is close to the shoulder of the air inlet periphery of the frame. Thereby, the axial end surface of the stator cooperates with the shoulder, so that the fan performance of the pole core disk portion is increased. The shoulder may use the inner wall surface of the frame. Such a structure can be used by only one of the end surfaces of the stator or by each of the two end surfaces. It is effective when used with a cooling fan. Such a structure achieves the same cooling performance that can be obtained if the wind is produced only by the cooling fan without increasing the number of processing steps and the number of parts. Thus, a higher output can be obtained. The input side means a side on which an input member for generating wind, such as a pulley, is provided.

In the invention of claim 8, the cross section of the conductors in the slots is substantially rectangular. Thus, the cross-sectional area of the conductors in the slots is increased, thereby increasing the space coefficient (ratio of the area occupied by the conductors to the area not occupied by the conductors in each slot) associated with the conductors in the slots. have. As a result, the resistance of the stator windings is reduced and higher output can be obtained. In addition, the area of the opposing surface of the conductors and the slot inner wall surface is increased and the thermal conductivity is much better. Thus, a decrease in temperature can be achieved, and thus a higher output can be obtained.

10. The invention of claim 9, wherein a plurality of conductors are accommodated in the slots and electrically insulated from each other, and the plurality of conductors are an outer layer located in a deep area of the slots and an inner side located at the opening side of the slots. Form one or more pairs of layers, and the conductors of the different layers in other slots of the slots are connected in series to form a stator winding. In the case where multiple phase windings are accommodated in the stator windings, such a structure can prevent interference between windings of different phases at the coil ends protruding at the axial end of the stator iron core. Thus, it is possible to position the conductors in the deep portions of the slots.

11. The combination of the plurality of conductor pieces and each conductor piece of the invention of claim 10, wherein one conductor portion is received in one slot as a conductor of the inner layer, the other straight portion and one end side is received in another slot as a conductor in the outer layer. And a U-shaped piece comprising a turn portion connecting the straight portions in and of a material continuous with the straight portion, wherein the U-shaped piece is a projection from a slot provided at the other end side of the straight portions. Is connected to the other of the conductor pieces. Such a structure allows multiple conductors to be located in the slots to form a stator winding even when the inner circumferential openings of the slots are narrower than the minimum width of the conductors. In addition, because the bends are provided, the stator winding can be formed while simplifying the steps of inserting the conductors into the slots and connecting the conductors.

The use of conductor pieces having such a structure makes it possible to employ the following structure. The bends of the U-shaped pieces provided in the stator iron core are arranged and aligned on one end surface of the stator iron core, and the connection between the conductors is such that the other end surface of the stator iron core is such that the connections of the conductor pieces are located only on the other end surface side. Only on the side. According to such an arrangement, winding formation is easy and productivity can be increased.

12. The stator winding of claim 11 wherein the stator winding comprises a combination of a plurality of conductor pieces, each conductor piece being a straight portion received in the slot as a conductor of the inner layer or the outer layer, and two ends of the straight portion. And a piece that is connected to another of the pieces of the conductor by protrusions from the slot provided in the. Such a structure allows multiple conductors to be located in the slots to form a stator winding even if the inner circumferential openings of the slots are narrower than the minimum width of the conductors. In addition, the shape of the conductor pieces can be simplified, so that inexpensive devices can be manufactured.

In the invention of claim 12, the conductors in the slots have a cross section having a rectangle with a long side extending along the radial direction of the stator, and each conductor has two lengthwise surfaces opposite the inner wall surface of the slot, And the conductors are arranged and received in the slots. Thus, the ratio of the opposing area between the surface of the conductors and the iron core can be increased, and the heat conduction from the conductor to the iron core can be improved.

1 is a cross-sectional view of a part of a stator of an automotive alternator according to a first embodiment of the present invention;

2 is a relationship between the output current and the rotational speed in the alternator.

3 is a cross-sectional view of an automotive alternator according to a first embodiment of the present invention.

4 is a cross-sectional view of a part of a stator of a vehicular alternator according to a second embodiment of the present invention;

5 is a perspective view of an electrical conductor piece.

6 is a perspective view of a coil end;

7 is a perspective view of an electrical conductor piece of another embodiment of the present invention.

8 is a sectional view of a stator modification.

9 is a cross-sectional view of an automotive alternator according to another embodiment of the present invention.

10 is a perspective view of a portion of the prior art winding formed above.

Figure 11 (a) is a cross-sectional view of a portion of the prior art stator in which no protrusions for collecting magnetic flux are made.

Figure 11 (b) is a cross-sectional view of a portion of the prior art stator in which protrusions for collecting magnetic flux are made.

1 to 3, an automotive alternator 1 according to a first embodiment of the present invention includes a stator 2, a rotor 3, two frames 4, and a rectifier 5. . The stator 2 serves as an armature. The rotor 3 serves to generate a magnetic field. The frame 4 supports the stator 2 and the rotor 3. The rectifier 5 is directly connected to the stator 2. The rectifier 5 converts the AC output into a DC output. The output side of the rectifier 5 is connected to a battery for generating a voltage of 12V.

The rotor 3 revolves with the shaft 6. The rotor 3 comprises a Lundel pole core 7, a cooling fan 11, a field coil 8, and slip rings 9 and 10. The shaft 6 is connected to the pulley 12 and is rotated and driven by an engine (not shown) for operating the vehicle.

Each Lundel pole core 7 comprises a boss portion 71, a disc portion 72 and eight hooked poles 73. The boss portion 71 is attached to the shaft 6. The disk portion 72 extends radially from two ends of the boss portion 71.

Portions of the frame 4 which face the coil end 31 of the stator 2 have a discharge port 43 for cooling wind. The end face of the frame 4 in the axial direction has a cooling wind inlet 41.

The stator 2 comprises an iron core 32, a winding 33 provided on the iron core 32 and an insulator 34 for providing electrical insulation between the iron core 32 and the winding 33. Winding 33 includes a conductor. As described above, the stator 2 is supported by the frame 4. The iron core 32 is multilayered. The iron core 32 comprises a stack of thin steel sheets. The iron core 32 has an inner circumferential surface formed with many slots each having an open end 35 serving as an inlet. The iron core 32 has teeth between the slots. Teeth of the iron core 32 have magnetic flux collecting protrusions 36 extending in the circumferential direction. The flux collection protrusions 36 are preformed by pressing during the stages in which they were thin steel sheets.

The wire or electrical conductor forming the winding 33 has a diameter larger than the width of the inner opening of the slots. The iron core 32 has a first side and a second side in the axial direction. A portion of the winding 33 extends into the first slot from the first side of the iron core 32, and from the second side of the iron core 32, a second slot falling from the first slot at an electrical angle of 180 °. And extend out of the first slot into the second slot before extending out of the second slot into the first slot of the iron core 32. The winding 33 has a circulation of such parts forming one phase. For example, winding 33 has three phases separated by 120 ° electrical angle. The winding 33 is wavy or wrapped.

The advantages given by the embodiments of the present invention are described. The diameter of the wire or conductor forming the winding 33 can be increased without being limited to the width of the inner opening of the slots. Thus, the resistance and heat loss of the winding 33 can be reduced. Thus, a high alternator output can be obtained.

In the prior art structure, wedges made of insulating material block the inner openings of the slots to prevent the windings from moving out of the slots. In the embodiment of the present invention, since the winding 33 does not move away from the slots, there is no need to make such a wedge. Therefore, the number and cost of parts can be reduced.

It is desirable to form the magnetic flux collecting protrusion 36 on the teeth of the iron core 32 by a process other than plastic deformation. In this case, therefore, the magnetic properties of the magnetic flux collecting protrusion 36 can be prevented from being lowered due to the plastic deformation. Thus, the magnetic flux collecting protrusion 36 can have a sufficient magnetic flux collecting effect. Therefore, the output of the alternator 1 can be remarkably improved while operating at a low rotational speed.

The space coefficient is defined corresponding to the ratio of the conductor occupied area in the slot to the total area of the slot. First, second and third alternators having the same spatial coefficients were prepared. The first alternator is a prior art alternator in which the width of the inner opening of the slots is larger than the diameter of the wire forming the winding. In the second alternator, the width of the inner openings of the slots is smaller than the diameter of the wire forming the winding, and the magnetic flux collecting protrusions have been formed with a plastic deformation. The third alternator is identical to the alternator 1 of the embodiment of the present invention. Therefore, in the third alternator, the width of the inner openings of the slots is smaller than the diameter of the wire forming the winding, and the flux collecting protrusions are formed by a process different from the plastic deformation. In FIG. 2, the dashed line shows the relationship between the output current and the rotational speed of the first alternator, that is, the prior art alternator. In Fig. 2, the dotted line shows the relationship between the output current and the rotational speed of the second alternator. In Fig. 2, the solid line shows the relationship between the output current and the rotational speed of the third alternator, that is, the alternator 1 of the embodiment of the present invention. In Fig. 2 it is shown that the alternator 1 of the embodiment of the invention outputs a relatively large current while operating at low rotational speeds.

In the embodiment of the present invention, the magnetic flux collecting protrusions 36 are free of geometric deformation caused by the plastic deformation. Therefore, the circularity of the inner circumferential surface of the iron core 32 is excellent. Therefore, it is possible to suppress an increase in magnetic noise which may be caused by the nonuniformity of the air gap between the stator 2 and the rotor 3.

The flux collection protrusion 36 can be made sufficiently long by a pressing process or other process that is different from the molding deformation. Thus, the inner circumferential surfaces of the iron core 32 can be close to the true winchoidal surface. Thus, it is possible to reduce the ruggedness of the inner circumferential surface of the iron core 32 and the wind noise caused by the centrifugal wind generated by the Lundel pole cores 7.

The prior art alternator of the external fan type is provided with an external cooling fan. In the prior art alternator of the outer fan type, the inner openings of the slots form an axial wind passage. Thus, in the prior art alternator of the external fan type, if the inner openings of the slots become narrow as in the embodiment of the present invention, the resistance to the cooling wind increases, thereby reducing the cooling performance. On the other hand, the alternator 1 of the embodiment of the present invention houses a cooling fan therein. In the alternator 1 of the embodiment of the present invention, the cooling winds introduced along the axial direction are radiated outward in the radial direction. Therefore, in the alternator 1 of the embodiment of the present invention, the inner openings of the narrowed slots have little effect on the cooling performance.

Second embodiment

The second embodiment of the present invention is similar to the first embodiment except for the design change described later.

In the first embodiment of the present invention, the conductor or wire forming the winding 33 has a circular cross section. On the other hand, in the second embodiment of the present invention, at least portions of the conductors extending into the slots have a rectangle corresponding to the shape of the slots as shown in FIG. In particular, the portions of the conductor have a cross section formed to have a flat surface extending along the inner wall surface of the slots. Therefore, the space coefficient is increased, and the sum of the cross-sectional areas of the portions of the conductors in the slots is increased. As a result, it is possible to reduce the electrical resistance of the winding and also increase the alternator output.

In the second embodiment of the present invention, the area in which the iron core 32 and the windings 33 are coupled is increased. Thus, excellent thermal conductivity can be provided between the iron core 32 and the winding 33. Therefore, the temperature of the winding 33 can be further lowered. Since the space coefficient is increased, the strength of the entire stator 2 is increased. Therefore, the magnetic noise can be lowered.

In addition, since the slot openings 35 are closed by the flat portions of the conductor, the inner surfaces of the stator iron core 32 are closer to the smooth cylindrical surface compared to the case where the stator winding 33 uses a circular wire. Can lose. Therefore, it is possible to further reduce the ruggedness of the inner surfaces of the stator iron core 32 and the wind noise generated by the radial outward wind caused by the Lundel pole core 7 during rotation.

Also in the second embodiment, the dimension of the cross section of the stator winding 33 is larger than the slot opening width. The cross section of the stator winding 33 has a rectangular shape. The width of the long sides of the stator winding is greater than the slot opening width. As shown in the figure, the width of the short side of the stator winding is preferably larger than the slot opening width.

In the first embodiment of the present invention, a continuous wire was used to make the winding 33. On the other hand, the second embodiment of the present invention uses U-type conductor pieces each having a straight portion 33a and a curved portion 33c, as shown in FIG. The conductor pieces are inserted into the slots of the iron core 32 along the axial direction so that the straight portions 33a are aligned. Then, a portion of the conductor pieces on the side of the iron core 32 away from the bend 33c are bent, and the ends 33b of the conductor pieces are connected so that the winding 33 is made on the iron core 32. do. The connection between the ends 33b of the conductor pieces is made by ultrasonic welding, arc welding, soldering, or mechanical machining. It is much easier to make the winding 33 than when continuous wire is used to make the winding 33.

Portions of the conductors are divided into an outer layer located in the deep portion of the slots and an inner layer located in the inner openings of the slots. Portions of at least a pair of such conductors are provided per slot. The inner and outer layer pieces of conductors in the different slots are connected in series. Therefore, as shown in FIG. 6, the coil ends can be prevented from interfering with each other. Thus, portions of the conductor can be easily inserted into the deep portions of the slots and also high occupancy for the slots can be achieved. In Figure 6, the number of pieces of conductor per slot corresponds to four turns, and there are two pairs of outer and inner layers. Even if the number 2 of the pairs is different, different winding phases can be prevented from interfering with each other.

In a second embodiment of the invention, the winding is made of conductor pieces. In this case, it is easy to make each conductor into a rectangular cross section and a high space coefficient can be obtained. Conductor pieces may be formed by a pressing process. Therefore, material cost and manufacturing cost can be reduced.

Another embodiment

The second embodiment of the present invention uses nearly U-type conductor pieces. As shown in FIG. 7, nearly J-type conductor pieces can be used. In this case, nearly J-shaped conductor pieces are inserted into the slots along the axial direction of the iron core 32 such that its straight portion 33h is aligned. The ends of the nearly J-shaped conductor pieces on each of the two sides of the iron core 32 are then connected to form a winding 33. Since nearly all J-shaped conductor pieces have a simpler shape, it is much easier to make. Therefore, there is a cost advantage.

In the second embodiment, the cross section of the stator winding 33 has a rectangular shape such that its long side is installed to seal the slot opening 35. As shown in FIG. 8, the stator winding 33 can only be arranged in lines of portions along the radial direction, and its short sides can close the slot openings 35. Such a longitudinal stack arrangement of rectangular cross-section conductors is such that a large proportion of the opposed area between the conductor surface and the iron core in the slots is achieved compared to the case of using the horizontal stack arrangement of the rectangular cross-section conductors shown in FIG. 4. And also improve the thermal conductivity from the conductors to the iron core. It is possible to increase the circumferential gaps between the parts of the windings without changing the axial length of the coil ends 31, ie without increasing the electrical resistance of the winding. This can be clearly seen from Fig. 6 in which the coil ends with four revolutions per slot are perspective. Therefore, the wind resistance to the cooling wind by the cooling fan 11 in the radially outward direction can be reduced, and accordingly, the flow rate of the cooling wind can be increased. Since the cooling wind flows through the coil end 31, the cooling performance can be increased and the alternator output can be further increased.

In the embodiment of the present invention shown in FIG. 7, the winding 33 has a reduced resistance and has a margin of cooling performance. Therefore, only one cooling fan provided at one end of the rotor 3 is sufficient. In this case, it is possible to reduce the number of parts and the number of manufacturing steps. Therefore, the alternator can be cheaper and smaller in size.

9 shows an alternator having only one cooling fan 11. In the alternator of FIG. 9, the end face of the rotor 3 without the cooling fan 11 is opposed adjacent to the inner wall surface of the frame (housing) 4 around the inlet 41. In this case, the inner wall surface of the frame (housing) 4 serves as a shoulder for the cooling fan 11. Therefore, the fan capability of the pole core disk portion 72 is increased. Therefore, the cooling performance comparable to the cooling performance obtainable in the structure having two cooling fans can be obtained without increasing the number of parts and the number of manufacturing steps. In addition, the output of the alternator can be further increased.

Claims (12)

Rotor; A stator located outside of the rotor and facing the rotor; And a frame for supporting the rotor and the stator; The stator includes an iron core and a plurality of electrical conductors, the iron core has a plurality of slots, the electrical conductors are located in the slots, the slots have openings, and the openings define the slots. And a width smaller than the width between the inner walls, the width of the openings of the slots being smaller than the minimum width of the conductors. 2. The vehicle alternator of claim 1, wherein the slots have two end surfaces in the axial direction of the stator iron core in which end surface openings are formed as inlets for the electrical conductors. 3. The method of claim 1, wherein the openings in the interior of the slots are narrower than the width of the conductor receptacles of the slots and are narrower than the minimum width of the conductors before the conductors are located in the slots. Vehicle alternator. 2. The vehicle alternator of claim 1, wherein the conductors have a circular cross section having a diameter greater than the width of the openings of the slots, and the conductors are provided in the slots to form a winding on the stator. 3. The vehicle alternator according to claim 1 or 2, wherein a cooling fan is provided at at least one shaft end of the rotor facing the stator. The alternator for a vehicle according to any one of claims 1 to 3, wherein cooling fans are installed at both shaft ends of the rotor facing the stator. 6. The vehicular alternator as claimed in any one of claims 1 to 5, wherein the distal surface of the rotor in the axial direction is close to the shoulder portion of the periphery of the air inlet of the frame. 8. The vehicle alternator according to any one of claims 1 to 7, wherein the cross section of the conductors in the slots has a rectangular shape. 9. The method of any one of claims 1 to 8, wherein a plurality of conductors are received in the slots while being electrically insulated from each other, and the plurality of conductors are located at the opening side with an outer layer and slots located in a deep area of the slots. And one or more pairs of inner layers located, and conductors of different layers in different slots of the slots are connected in series to form a stator winding. 10. The stator winding of claim 9, wherein the stator winding comprises a combination of a plurality of conductor pieces, each of the conductor pieces being received in one slot as a conductor in the inner layer and in another slot as a conductor in the outer layer. A U-shaped piece made of a material continuous with the other straight portions and straight portions being formed, and also having a bend connecting the straight portions at one end side, the U-shaped pieces being provided on the other end side of the straight portions. A vehicle alternator characterized in that it is connected to another of the pieces of the conductor by protrusions from the slot. 10. The stator winding of claim 9, wherein the stator winding comprises a combination of a plurality of electrical conductor pieces, each of the conductor pieces being a straight portion received in the slot as a conductor of the inner layer or the outer layer and two ends of the straight portion. And a piece that is connected to another of the pieces of the conductor by protrusions from the slot provided in the. 12. The conductor according to any one of the preceding claims, wherein the conductors in the slots have a cross section having a rectangular shape with elongated sides extending along the radial direction of the stator, and each of the conductors is in the longitudinal direction, the inner wall surface of the slot. A vehicle alternator having two surfaces facing the conductors, and the conductors arranged and received in the slots.