WO2008000992A2

WO2008000992A2 - Stator for rotary electric machine and one such machine

Info

Publication number: WO2008000992A2
Application number: PCT/FR2007/051436
Authority: WO
Inventors: Stéphane Desenclos; Dominique-Alain Ramet; Stéphane RAMET; Alain Defebvin; Rodolphe Lecornet; Philippe Mantelle
Original assignee: Valeo Equipements Electriques Moteur
Priority date: 2006-06-28
Filing date: 2007-06-14
Publication date: 2008-01-03
Also published as: FR2903245B1; WO2008000992A3; FR2903245A1

Abstract

The stator for rotary electric machine comprises a body (4) equipped with notches for mounting a stator winding (51) forming an outer coil respectively in front (5) and in back (53) of each axial extremity of the body (4), at least one of the coils (5) being fashioned to provide a first section for a grounding (500) in the body (4) of the stator (50), extended by a second outer section (501) that is compact in order to give a flared shape to its inner periphery. The rotary electric machine comprises said stator. Use: Stator for alternator, alternator-starter, or electromagnetic retarder.

Description

"Stator for rotating electric machine and rotating electrical machine having such a stator".

Field of the invention

The invention relates to a stator for a rotating electrical machine and a rotary electrical machine comprising such a stator of the type comprising a body provided with notches for mounting a stator winding forming an external bun at each axial end of the body.

State of the art

Referring to Figure 1, there is shown a rotating electrical machine of the state of the art, in this case an alternator with internal ventilation of the polyphase type for a motor vehicle engine operating in alternator mode. Of course the alternator can also be reversible and consist of an alternator-starter also operating in electric motor mode, in particular for starting the engine of the vehicle as described in document FR A 2,745,445.

When the machine operates in alternator mode, it transforms mechanical energy into electrical energy like any alternator. When the machine operates in electric motor mode, especially in starter mode to start the engine of the vehicle, it transforms electrical energy into mechanical energy.

This machine essentially comprises a housing 1 and, inside thereof, a rotor 2 integral in rotation with a central shaft 3, called a rotor shaft, and a stator 50 of annular shape, which surrounds the rotor 2 with the presence of an air gap and which comprises a body 4 in the form of a pack of sheets with notches, for example of the semi-closed type, for mounting a stator winding 51 forming a on either side of the body 4 stator 5, at each axial end thereof, an outer bun 5, 53 protruding axially.

This winding 51 comprises, for example, a set of three-phase star or delta windings, the outputs of which are connected to a rectifier bridge, partially visible at 52, comprising rectifying elements such as diodes or MOSFET transistors, especially when the machine consists of an alternator-starter.

The windings of the winding 51 are obtained using a continuous, electrically conductive wire coated with an electrically insulating layer, such as enamel, and mounted in the respective notches of the body 4 of the stator 50 via insulators. notches (not visible).

According to another variant, the winding 51 comprises two sets of three-phase windings to form a device for composite stator windings, the windings being shifted by thirty electric degrees as described for example in the documents US-A1-2002 / 0175589, and FR -A-2784248. In this case, two rectifier bridges are provided and all combinations of three-phase star and / or delta windings are possible. In a variant, the stator winding is of the pentaphase type.

In general, the alternator is of the polyphase type and the rectifier bridge or bridges make it possible in particular to rectify the alternating current produced in the windings of the stator 50 into a direct current, in particular for charging the vehicle battery. and supply the loads and electrical consumers of the on-board network of the motor vehicle.

The rotor 2, of annular shape, is made in the example shown in the form of a claw rotor, as described for example in the documents US-A1-2002 / 01 75589, comprising two pole wheels 7,8 here axially juxtaposed and each having an annular transverse flange provided at its outer periphery with claws 9.

Each claw 9 has a rooting section of transverse orientation in the plane of the flange concerned. This rooting section is extended at its outer periphery by a generally axial orientation tooth with presence of a chamfer between the tooth and the rooting section.

An annular gap exists between the outer peripheral face of the teeth of the claws 9 and the inner periphery of the body 4 of the stator 50.

The teeth are generally trapezoidal or triangular. The teeth of a pole wheel 7, 8 are directed axially towards the flange of the other pole wheel 8.7; the tooth of a wheel 7,8 penetrating the space between two adjacent teeth of the other wheel 7,8, so that the teeth of the wheels 7,8 are interleaved. For more details, see EP 051 5 259.

An excitation winding 10 is implanted axially between the flanges of the wheels 7,8. It is carried by a rotor portion 2 in the form of a cylindrical annular core coaxial with the shaft 3. The core of FIG. 1 consists of two axially distinct sections, each of which is made integral with a pole wheel 7, 8 associate. According to a variant not shown, the central core consists of a single piece and is distinct from the pole wheels 7.8, 22 which are arranged axially on either side of the core.

The winding 1 0 is thus implanted in the space delimited radially by the claws 9 of the wheels 7,8 and the central core.

The wheels 7, 8 and the core are preferably of ferromagnetic material and are coaxially traversed by the rotor shaft 3 also made of ferromagnetic material. These wheels 7, 8 are integral with the shaft 3. For this purpose, each wheel 7,8 has a central bore which passes axially through the flange and extends the bore of the part of the core concerned. The shaft 3 has knurled portions (not referenced) and is force-fitted into the aforementioned bores of the core and the wheels 7, 8 so that it cuts grooves through its knurled portions. The shaft 3 is thus integral in rotation and axially wheels, a spacer, not referenced, being interposed between the wheel 7 and a bearing 1 9 described below.

The axis of the shaft 3 constitutes the X axis of the machine.

The winding wire 1 0 is wound on a support of electrically insulating material (not shown) mounted, preferably by force, on the outer periphery of the core.

When the excitation winding 1 0 is activated, that is to say electrically powered, the wheels 7,8 and the core are magnetized and the rotor 2 becomes an inductor rotor with the formation of magnetic poles at the claws 9 wheels 7,8.

This inductor rotor 2 creates an alternating induced current in the stator 50 induced when the shaft 3 rotates.

The shaft 3 of the rotor 2 carries at its front end a movement transmission member 12, here a pulley 1 2 belonging to a device for transmitting motion via less a belt (not shown) between the alternator and the engine of the motor vehicle. This shaft carries at its rear end slip rings 1 3 connected by wire bonds (not shown) to the ends of the excitation winding 1 0 of the rotor 2.

Alternatively the pulley 12 is replaced by a gear and the transmission device is chain and / or gear.

Brushes belong to a brush holder generally represented at reference 14 and they are arranged so as to rub on the slip rings 13, in order to feed the winding

1 0 in electric current. The brush holder 14 is connected to a voltage regulator (not shown).

The casing 1 is here in two parts, namely a front bearing 16 adjacent to the pulley 12 and a rear bearing 17 carrying the brush holder 14 and most often the rectifier bridge or bridges and the voltage regulator. The bearings 16, 17 of annular shape, for example based on aluminum, are hollow in shape and each bear a central ball bearing respectively 19 and 20 for the rotational mounting of the shaft 3 of the rotor 2. The bearings are assembled together using tie rods or screws as visible for example in Figure 1 of EP 0515 259 supra.

In Figure 1 there is provided at the outer periphery of the body 4 of the stator, in the form of a sheet package, an elastic system for filtering vibrations, with a flat seal 40 at the front and at the back of the pads 41, the flexible and thermoconductive resin being interposed between the front bearing and the stator body to evacuate the heat.

In a variant, no seals are provided. In all cases the stator is fixedly carried by the casing 1, while the rotor 2 is carried centrally rotatably by the casing 1 via the bearings 19, 20.

Alternatively the housing is in three parts, the bearings 16, 17 being disposed on either side of a central portion carrying the body of the stator. The bearings are assembled to the intermediate portion for example by screwing.

The alternator also comprises means for cooling it. For this purpose, in FIG. 1, the bearings 16, 17 are perforated to allow the cooling of the alternator by air circulation and the rotor 2 carries at least at one of its axial ends a fan intended to provide this. air circulation. Here a first fan 23 is provided on the front face of the rotor 2 and a second fan 24, more powerful, on the rear face of the rotor 12. Each fan 23,24 is ring-shaped and is provided with a plurality of blades 26 and is fixed on the outer radial faces of the flanges of the wheels 7,8.

The fans are for example metallic and are obtained with their blades 26 by cutting and folding. The fans 23, 24 are for example centrifugal or helico-centrifugal type.

FIG. 1 shows by arrows the flow of air at the level of the front bearing 16, this bearing 16 comprising a plurality of air inlet orifices 60 and a plurality of outlet orifices 61 of FIG. air. The rear bearing 17 also has a plurality of air inlet and outlet ports.

In FIG. 1, the brush holder 14 and the voltage regulator, integral with the bearing 17, are capped by a cap 70, integral with the rear bearing 17, being fixed here on the latter, in known manner, by snapping onto studs 71 integral with the rear bearing. This hood 70 also has air intake orifices, not visible in FIG. 1.

This provision gives satisfaction. Nevertheless it may be desirable to further reduce the noise of the machine.

Object of the invention

The present invention aims to meet this desire. According to the invention a stator of the above-mentioned type in which at least one of its buns is shaped to present a first rooting section to the body of the stator extended by a second external section, is characterized in that the second section external is compacted to present at its inner periphery a flared shape. Thus the second outer portion is shaped at its inner periphery to have a flared shape and is denser than the first section so that the first section is more permeable for the passage of air.

A rotating electrical machine of the type indicated above is characterized in that it comprises such a stator.

Thanks to the invention the shape of the bun allows better air circulation.

More precisely, once the stator is mounted in the machine, better circulation of air is obtained between the fan, the stator and the bearing concerned. In one embodiment this is achieved without reducing the size, including the external diameter, of the fan concerned and therefore without reducing the performance of the machine.

In one embodiment the shaped bun is the front bun. Thanks to the invention, this avoids a noise level, especially hissing, annoying for the human ear at certain rotational speeds of the shaft of the rotating electrical machine.

Generally speaking, at a constant air flow rate, the passage section is increased, for example between the front bun and the front bearing, which makes it possible to reduce the speed of the air flow and thus reduce the noise generated. when the rotor shaft and front fan rotate.

This is applicable to the rear bun.

In one embodiment the second section is of frustoconical shape at its inner periphery.

This second section opens at its inner periphery facing the outlets.

This characteristic makes it possible to reduce the noise even more, the air having more facilities to circulate. According to other characteristics taken separately or in combination: the rear bun is shaped to also have a first rooting section to the body of the stator extended by a second external section compacted to present at its inner periphery a flared shape; the second section of the rear bun is frustoconical in shape at its inner periphery. ; the second section of the rear bun opens at its inner periphery facing the outlets. Thanks to the invention can increase the outer diameter of the rear fan without increasing noise through the increase of the passage section between the rear bun and the rear bearing.

Thanks to the increase of the size of the rear fan one gets a better cooling of the machine. In one embodiment, the front bun is not modified, only the rear bun is modified to present a second section according to the invention.

Brief description of the drawings

The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the following explanatory description made with reference to the accompanying drawings given solely by way of example illustrating a mode of operation. embodiments of the invention and in which:

- Figure 1 is an axial sectional view of a rotary electrical machine of the state of the art; - Figure 2 is a partial half-view in axial section of an electric machine according to the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION In the remainder of the description, similar, similar or identical elements will be designated by the same reference number.

FIG. 2 shows a part of the alternator of FIG. 1, namely the upper part of FIG. 1 and in particular the left part thereof comprising the pole wheel 7, the front end of FIG. the shaft 3, the front bun 5, a part of the body 4 of the stator 50 carried by the housing 1, the front bearing 16 of annular shape with its bearing 19, the pulley 12 and the front fan 23.

This fan 23, here metallic and centrifugal type, is fixed on the end face of the pole wheel 7, for example by spot welding or alternatively by riveting with rivets. In one embodiment the rivets are rivets obtained by extrusion from the wheel 7. It is the same with respect to the rear fan 24.

The air inlet 60 and air outlet openings 61 have an oblong shape. The orifices 60 are circumferentially oblong, while the orifices 61 are axially oblong.

More specifically, arms are present between the orifices 60, while fins are present between the orifices 62. The surface of the air inlet orifices 60, for example of generally trapezoidal shape, is smaller than the surface of the outlet orifices. 61.

The bearing 16, here based on aluminum, has a bottom 1 60, generally oriented transverse to the axis X of the shaft 3 and the alternator. This bottom 160 has centrally a cylindrical core 1 62 for mounting the outer ring of the bearing 1 9.

The core 1 62 internally defines the orifices 60 formed in the bottom 160 and is integral with the aforementioned arms. This bottom 1 60 is extended at its outer periphery by a flange 1 61 of generally annular and globally oriented shape with axial orientation relative to the axis X. The orifices 61 are formed in this flange 1 61 are of axial orientation .

More specifically, these orifices 61 have a portion that affects the flange 61 and another portion, of smaller size, which affects the outer periphery of the bottom 1 60.

The bearing 1 7 has a shape similar to that of the bearing 1 6 and is provided with air inlet orifices and outlet openings to the orifices 60, 61. The bearing 1 7 thus has a bottom 160 'of generally transverse orientation in which are made the air inlet ports 60'.

This bottom 1 60 'is extended at its outer periphery by an annular rim generally of axial orientation not shown for clarity and provided with axially oriented air outlet orifices also affecting the outer periphery of the bottom 1 60' as visible in 61 '.

For simplicity, it has been shown that part of the carrier 14 and the rotor 2 with claws 9 has not been cut. One of the diodes (not referenced) of the rectifier bridge is also seen. This diode is located at the outer periphery of the bottom 160 '.

On the other hand, there are air inlet openings 170 made in the bottom of the annular cover 70. The arrows in this figure 2 represent the flow of air generated by the fans 23, 24 when the shaft 3 rotates.

The rear fan 24 is more powerful than the front fan 23. It has been found in some applications that the alternator of Figure 1 is noisy, especially at the front and half rotation.

To eliminate these noises resulting in a hiss of ventilation at half rotational speed it is proposed to modify the front bun 5 so that it has a first rooting section 500 to the body 4 of the stator 50 extended by a second external section 501 shaped to its inner periphery to present a flared shape.

This form of the front bun allows a better air circulation between the front fan 23, the front bun 5 of the stator 50 and the front bearing 1 6, the bead being directed outwards toward the bottom 160. At a constant air flow, the section of passage between the front bun 5 and the front bearing 16 is increased, which makes it possible to reduce the speed of the air flow and the noises when the front fan 23 is rotating. In Figure 2 the second section 501 is of frustoconical shape at its inner periphery.

The inner periphery of this second section 501 opens opposite the outlet orifices 61 of the flange 161 of the bearing 16.

To better show this, the inner periphery of the second section 501 has been extended in FIG. 2 by a line 200. This line 200 passes through the adjacent outlet orifices 61.

Here the line passes through the outlet orifices 61 at the portion thereof affecting the outer periphery of the bottom 160.

The second section opens out facing portions of the outlet ports affecting the bottom 160.

In one embodiment, the rear bun 53 is identical to the rear bun of FIG.

Of course we can also conform the rear bun

53 so that it also has a first rooting section to the body of the stator extended by a second outer portion formed at its inner periphery to have a flared shape.

The flaring of the second section or sections is directed outwards towards the bottom of the nearest bearing concerned. This second section of the rear bun is in a frustoconical embodiment at its inner periphery. ;

The inner periphery of this second section of the rear bunion 53 opens opposite the outlet orifices 61 'of the rim of the rear bearing in the same manner as the section 501, the outlet orifices of the rear bearing being similar to the orifices 61. The second section of the bun 53 is in an embodiment of frustoconical shape as the second section of the front bun 5.

In this figure 2 there is shown a curved variant of the flared shape of the rear bun 53. This variant is applicable to the front bun 5. This curved shape allows greater ease of passage of air through the orifices 61.

More specifically, the internal diameter of the second section increases continuously towards the free end of the rear bun.

Of course alternatively the front bun of Figure 1 is retained and only the rear bun has the second section of the invention.

This arrangement makes it possible to increase the outside diameter of the rear fan 24 without increasing the noise by increasing the air passage section between the rear bun 53 and the rear bearing 17.

The machine's performances are thus increased thanks to a better cooling of the machine. It will be appreciated that the frustoconical shape is easier to achieve than that of the more efficient variant with a curved shape.

These shapes are obtained, according to a characteristic, by compacting the ends of the buns and son of the winding 51 of the stator 50 with the aid of pressing tools. Thus the second section is denser than the first non-compacted section.

The solution of FIG. 2 makes it possible not to modify the external periphery of the buns 5, 53 extending in axial projection on either side of the body 4. These buns comprise, in known manner, a plurality of electrically conductive wires of the made that, as previously mentioned, the winding 51 comprises several windings obtained using an electrically conductive continuous wire which is mounted in the notches of the stator body; strands of the wire belonging to different notches of the stator body being connected to the outside of the body by a connecting part belonging to one of the buns

The buns 5, 53 are modified only at their second section 501. This arrangement allows to leave intact the buns 5, 53 at their first rooting portion 500 most permeable to the passage of air so that a good cooling chignons. In addition, the stator winding 51 is not modified inside the body 2, this winding 51, as well as the slot insulators, being held and fixed in the body 4 by an impregnating varnish which is a good conductor of heat and thus making it possible to dissipate the heat by conduction to the body 4 and the bearings 1 6, 17.

By compacting the electrically conductive son of the coil 51 at the second section 501 son are brought closer to each other so that the heat is better conduction. In addition, the path of the air passes, as mentioned above, through the outlet orifices 61, 61 ', which allows the heat to be dissipated.

If need be we can in one embodiment bind the son of the second section 501, after compaction, with a good heat conductor varnish.

As is apparent from the figures and the description, the body 4 being of annular shape, the buns are annular in shape, their outer periphery being generally of cylindrical shape as in FIG. The first section 500 is therefore generally tubular. In the embodiment of FIGS. 1 and 2, the ring-shaped rotor has six claws per pole wheel and thus 1 2 poles, as in the aforementioned EP 0 515 259 and the body 4 has 36 notches for mounting the winding 51, the alternator being of the three-phase type.

With the alternator of Figure 1 there was a hissing midrange, this hiss is measurable is quantifiable on the order 1 8.

Thanks to the invention, this whistle is eliminated. Of course, in a variant, the number of poles of the claw rotor is different from 12, each pole wheel comprising, for example, 7 or 8 poles.

Similarly, the number of notches can be doubled, the claw rotor having for example 1 2 poles and the stator 72 notches. It will be noted that the first section 500, and therefore the inner axial end of the second section 501, extends generally to the axial end of the teeth 90 of the claws 9 delimited by the chamfer 91 arranged between the tooth 90 concerned and the rooting section of the claw 9 to the flange of the front polar wheel 7. Thus a large clearance exists between the inner periphery of the section 501 and the chamfers 91.

This clearance, ring-shaped, has a V-shaped section.

The outer periphery of the front fan 23 extends in this clearance, the external diameter of the fan being generally equal to the outer diameter of the teeth and lower than that of the inner diameter of the first section 500.

The same configuration is applicable to the rear bearing 1 7 and the rear fan 24, whose outer diameter can be thus slightly increased in the above manner without increasing the noise.

The best cooling thus obtained makes it possible to reduce the outside diameter of the front fan when the alternator is noisy. This decrease in diameter reduces noise.

The fan or fans 23, 24, of annular shape, extend in axial projection relative to the concerned bun being axially offset relative to the second section and in the direction of the bottom of the rear bearing. It will be appreciated that the fan 23 of FIG. 1 is unchanged in this embodiment.

It would have been possible, to reduce the noise, reduce the outer diameter of the fan 23 to the detriment of a loss of power. Thanks to the stator according to the invention the noise is reduced without changing the fan.

The noises are also reduced without changing the bearings 16, 17.

In a variant, the fins delimiting the outlet orifices 61 are inclined axially and circumferentially as described in the document FR 2869477. Naturally, the present invention is not limited to the embodiments described.

Thus in one embodiment the first section 500 is extended and the second section 501 shorter.

The first section extends at least as far as the axial end of the teeth delimited by the chamfer 91.

According to a variant not shown, the alternator can also be cooled by a heat transfer fluid, such as the cooling fluid of the engine of the vehicle, the casing 1 then being configured to include a suitable circulation channel of the heat transfer fluid. For example the front bearing 16 and the fan 23 are unchanged, while the rear bearing 17 is modified to present the fluid circulation channel, the rear fan 24 being removed.

The reverse can also be done, the rear bearing 17 and the fan 24 being unchanged, while the front bearing presents the channel, the fan 23 being eliminated.

In both cases respectively the front bun 5 and the rear bun 53 have a second outer section.

The power of the machine can be further increased by using more efficient fans with a large number of blades 26, such as fans obtained by superimposing two elementary fans each comprising a series of blades as described for example in the document FR A 2741 912. and as visible in Figure 1 (rear fan 24). The front fan 23 may also be a fan with a large number of blades, for example a fan obtained by superimposing two elementary fans such as the fan 24 of FIG. 1. This fan will not be noisy thanks to the modification of the front bun according to FIG. 'invention. According to a variant not shown, the performance of the machine, namely its power and efficiency, can be further increased by using a rotor 2 which comprises, for example as described in French patent FR-2 784 248, a number of permanent magnets interposed between two adjacent teeth claws 9 at the periphery of the rotor 2. We choose the number of these magnets so that it is equal to or less than the number of poles of the rotor and that their arrangement is symmetrical with respect to the rotor axis. For example, there are four, six or eight pairs of magnets for eight pairs of poles. Alternatively, the rotor may have salient poles, as described for example in WO 02/054566, and then comprises a plurality of excitation coils each wrapped around such a pole. In the same way the blades of the fans can be reported individually on the rotor.

Of course alternatively the engine and the alternator can be fixed.

The rotating electrical machine is alternatively an electromagnetic motor vehicle retarder comprising an alternator for electrically supplying the rotor coils of the electromagnetic retarder.

In this case the stator of the alternator is an inductor stator and the rotor of the alternator an induced rotor with the presence of a current rectifier between the rotor of the alternator and the rotor of the retarder as described for example in the document FR-

2 865 080 to which reference will be made for more details.

In this document the machine is cooled by circulation of a fluid and by circulation of air. The stator of the alternator is then provided with a bun according to the invention and the fan is in an embodiment of the centrifugal or helical centrifugal type.

As can be seen from the description and from FIG. 2, at least one of the stator bunches is shaped to present a first rooting section to the stator body extended by a second external section shaped at its inner periphery to present a flared shape, said second section being compacted for this purpose.

Thanks to the invention it does not degrade the performance of the machine from the thermal point of view. Of course, as a variant, the external diameter of the front or rear fan is greater than the external diameter of the rotor because the fan concerned is then facing the inner periphery of the second compacted section of its associated bun, said fan being in the aforementioned manner offset axially. towards the bottom of the bearing relative to the second section and therefore with respect to the first section.

Thanks to the invention, it is possible, in a prior manner, to use bearings 1 6, 1 7 of the prior art because the cylindrical and axially oriented outer circumference of the annular bunches 5, 53 is unchanged.

Claims

1. Stator for a rotating electrical machine comprising a body (4) provided with notches for mounting a stator winding (51) forming an outer bun, respectively before (5) and rear (53), at each axial end of the body ( 4), wherein at least one of the front (5) and rear (53) bunches is shaped to present a first rooting section (500) to the body (4) of the stator (50) extended by a second external section (501), characterized in that the second section (501) is compacted to present at its inner periphery a flared shape.

2. Stator according to claim 1, characterized in that the second section (501) of the bun (5, 53) is of frustoconical shape at its inner periphery.

3. Stator according to claim 1, characterized in that the stator winding (51) is electrically conductive son and in that the son of the second section (501) of the bun (5, 53) are bonded by a good conductor varnish heat.

4. Stator according to claim 1, characterized in that the first section (500) of the bun (5, 53) is more permeable to the passage of air than the second section of the bun (5, 53).

5. Rotating electrical machine comprising a housing (1) carrying a stator (50) surrounding a rotor (2), characterized in that it comprises a stator according to any one of the preceding claims.

Rotary electric machine according to claim 5, characterized in that the casing (1) comprises at least one front bearing (1 6), in that the rotor carries a front fan (23), in that the front bearing ( 16) has a plurality of air inlet (60) and outlet (61) ports, in that the front bun (5) of the stator (50) is shaped to present a first rooting section (500) to the body (4) of the stator (50) extended by a second outer section (501) compacted to have a flared shape at its inner periphery and in that the second section (501) of the front bun (5) of the stator (50) opens at its inner periphery opposite the air outlet orifices (61) of the front bearing (16).

7. A rotary electric machine according to claim 6, characterized in that it has an axis (X), in that the front bearing (16) is hollow in shape and comprises a bottom (160) generally of transverse orientation relative to to the axis (X) extended at its outer periphery by a rim (161) generally axially oriented relative to the axis (X), in that the outlet orifices (61) comprise a portion affecting the outer periphery the bottom (160) and a portion affecting the flange (161) and in that the second section (501) of the front bun (5) of the stator (50) opens at its inner periphery opposite the portion of the outlet orifices air (61) affecting the outer periphery of the bottom (160) of the front bearing (16).

Rotary electric machine according to claim 5, characterized in that the casing (1) comprises at least one rear bearing (17), in that the rotor (2) carries a rear fan (24), in that the bearing rear end (17) has a plurality of air inlet and outlet ports, in that the rear bun (53) is shaped to present a first rooting section to the body (4) of the extended stator (50). by a second outer section compacted to present at its inner periphery a flared shape and in that the second section of the rear bun (53) opens at its inner periphery facing the air outlet orifices of the rear bearing (17).

9. A rotary electric machine according to claim 5, characterized in that it consists of an alternator or alternator-starter, in that it comprises an axis (X), in that the rotor (2) is a rotor with claws (9) having a front pole wheel (7) and a rear pole wheel (8) each having a flange of transverse orientation relative to the axis (X), in that the claws (9) each comprise an axially oriented tooth (90) with respect to the axis (X), a root portion of the flange of the pole wheel (7, 8) and a chamfer (91) arranged between the axial end of a tooth (90) and the rooting portion to the flange, in that the front bun (5) has a first section (500) extended by a second section (501) compacted and that the first section of rooting (500) of the front bun (5) extends at least to the axial end of the teeth (90) of the front pole wheel (7).

1 0. A rotary electric machine according to claim 5, characterized in that it consists of an alternator or alternator-starter, in that it comprises an axis (X), in that the rotor (2) is a rotor with claws (9) having a front pole wheel (7) and a rear pole wheel (8) each having a flange of transverse orientation relative to the axis (X), in that the claws (9 ) each comprise an axially oriented tooth (90) with respect to the axis (X), a root portion of the flange of the pole wheel (7, 8) and a chamfer (91) arranged between the axial end of a tooth (90) and the rooting portion of the flange, in that the rear bun (53) has a first section extended by a second compacted section and that the first section of rooting of the rear bun (5 ) extends at least to the axial end of the teeth (90) of the rear pole wheel (8).

1 1. Rotary electric machine according to claim 9, characterized in that clearance exists between the periphery internal of the second section (501) of the front bunion (5) and the chamfers (91) of the front pole wheel (7) and in that the outer periphery of the front fan (23) extends in the clearance.

1 2. A rotary electric machine according to claim 10, characterized in that a clearance exists between the inner periphery of the second section of the rear bun (53) and the chamfers (91) of the rear pole wheel (8) and that the outer periphery of the rear fan (24) extends into the clearance.