EP1508193A1

EP1508193A1 - Alternator equipped with stator having twisted inputs

Info

Publication number: EP1508193A1
Application number: EP03755189A
Authority: EP
Inventors: Denis Even; Pierre Faverolle; Jean-Luc Tarrago
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2002-05-28
Filing date: 2003-05-23
Publication date: 2005-02-23
Also published as: WO2003100945A1; MXPA04011782A; FR2840464A1; JP2005528075A; JP4374081B2; US7170210B2; US20060001326A1; FR2840464B1

Abstract

The invention concerns an alternator, in particular for motor vehicle, comprising a stator (13) provided with a cylindrical body (14) bearing several phases (P), each phase comprising an input (E1 to E3) and an output, and electrically conductive interconnected elements (50) connecting the phase inputs to the phase output, the inputs (E1 to E3) consisting of rods having at least one longitudinal flat surface (21), each input including a first segment (25) passing through the body (14) of the stator (13) and a second end segment (26) extending from an axial side of said body (14), the second segments (26) of the inputs (E1 to E3) being electrically interconnected to form a neutral point (53). The invention is characterized in that the inputs (E1 to E3) are twisted, the flat surface (21) of each input (E1 to E3) extending along the first segment (25) in a radial plane, and extending along the second end segment (26) either to form a cylindrical portion coaxial with the body (14) of the stator (13), or in a plane tangential to a cylinder coaxial with the body (14) of the stator (13).

Description

"Alternator fitted with a stator with twisted inputs".

Technical field of the invention

The invention generally relates to alternators, in particular for motor vehicles.

More specifically, the invention relates to an alternator, in particular for a motor vehicle, comprising a stator provided with a cylindrical body carrying several phases, each phase comprising on the one hand an input and an output located at least partially outside the body of the stator, and on the other hand electrically conductive elements passing through the body of the stator to form two opposite axial sides thereof of the first and second buns, the conductive elements being electrically connected together to form at least one connecting winding the phase inputs to the phase outputs, the inputs consisting of bars having at least one longitudinal flat face extending along at least part of the bar, each input comprising a first segment passing through the body of the stator and a second end segment extending on an axial side of this body, the second segments of the inlets being located in the same c axial side of the stator body and being electrically interconnected to form a neutral point.

State of the art

Devices of this type are known from the prior art, in particular by French patent application 0116658, which will be published under the number FR-A- 2 818 822, in the name of VALEO which reveals an alternator whose neutral point can be achieved by arranging the phase inputs in different ways. The entrances are bars of rectangular section, thus presenting relatively wide opposite longitudinal flat faces called flat and relatively narrow opposite longitudinal flat faces called edges.

The stator body includes narrow radial notches, and the entry bars are engaged in these notches so that the flats of the first segments each extend in a substantially radial plane.

The inputs are shaped so that their second segments are in the form of portions of coaxial cylinders with the body of the rotor. The flats constitute the axial faces of these cylinder portions, and the edges the inner and outer radial faces. The second segments are therefore obtained by folding the first segments laterally, that is to say on the side of one or the other of the dishes.

The inputs are in contact with each other or with the neutral bar by the flats of their second segments. The neutral bar and the second segments of the inputs are therefore stacked axially.

This arrangement has the defect that it is very difficult to weld the inputs to each other or to the neutral bar after folding the electrically conductive elements, since there is not enough space available to introduce the welding head axially.

Patent documents EP 1 143 596 and US 5,998,903 disclose alternators comprising stators whose three inputs are joined at a neutral point. A first entry comprises a second axial end segment, the flats of this second segment extending in radial planes. The second segments of the other two inputs have, as in French patent application 01 16658, the shape of portions of cylinders coaxial with the body of the rotor. The flat constitute the axial faces of these cylinder portions, and the edges the inner and outer radial faces. These cylinder portions each extend by an axial orientation part, these axial parts being pressed by a plate on the two opposite plates of the second segment of the first entry.

This arrangement makes it possible to weld the inlets with one another after folding the pins, but has the drawback of increasing the axial size of the bun carrying the inlets.

Subject of the invention

In this context, the purpose of the present invention is to overcome the above-mentioned defects, and to propose several arrangements making it possible to weld the entries after bending the pins, without having to systematically resort to parts of axial orientation.

To this end, the device of the invention, moreover conforms to the generic definition given in the preamble above, is essentially characterized in that the entrances are twisted, the flat face of each entrance extending along of the first segment in a generally radial plane, and extending along the second end segment either to form a portion of cylinder coaxial with the body of the stator, or in a plane tangential to a cylinder coaxial with the body of the stator.

Thanks to the twist of the invention it is possible to easily and economically weld the entries after folding of the electrically conductive elements and this with a bun of reduced axial size.

To reduce the number of parts, in a possible embodiment of the invention, the second segments of the inputs are identical. Advantageously, the second segments of the inputs are electrically connected by a neutral bar of circumferential orientation, the second segments of the inputs being fixed to this neutral bar by their respective flat faces.

Preferably, the second segments of the inputs are of circumferential orientation, their respective flat faces forming portions of cylinders coaxial with the body of the stator. For example, the second segments of the inputs extend in an axial direction, their respective flat faces extending in planes tangent to the neutral bar.

Advantageously, a first entry comprises a second relatively long segment of circumferential orientation, two other entries comprising second segments of the same length relatively shorter than the length of the second segment of the first entry, the flat face of the second segment of the first entry. forming a portion of cylinder coaxial with the body of the stator, the second segments of the other two inlets being fixed by their respective flat faces on the flat face of the second segment of the first inlet.

Preferably, the second segments of the other two inputs are of circumferential orientation and extend in the same direction, clockwise or counterclockwise, their respective flat faces forming portions of cylinders coaxial with the body of the stator.

For example, the second segments of the other two inputs are of circumferential orientation, and extend in opposite directions, clockwise for one and counterclockwise for the other, their respective flat faces forming portions of coaxial cylinders at stator body. Advantageously, two inputs are joined by their respective second segments to constitute the two branches of a pin, these respective second segments being of circumferential orientation, the respective flat faces of these two second segments being arranged in the extension one of the 'other and forming a cylinder portion coaxial with the stator body, a third inlet being fixed by the flat face of its second segment to said portion of cylinder.

Preferably, the inputs are located at different angular positions around the axis of the rotor body, the two inputs joined together in a pin shape are consecutive following the periphery of the stator body.

For example, the inputs are located at different angular positions around the axis of the rotor body, the two inputs joined in a pin shape are not consecutive following the periphery of the stator body.

Advantageously, the second segment of the third entry is of circumferential orientation, its flat face forming a portion of cylinder coaxial with the body of the stator. Preferably, the second segment of the third entry extends in an axial direction, its flat face extending in a plane tangent to the second segments joined by the two entries forming a pin.

For example, the second segments of the inputs are of circumferential orientation and all extend in parallel over at least part of their length.

Advantageously, the second segments of the inputs all extend in the same direction, clockwise or counterclockwise. Preferably, the respective second segments of at least two entries extend in opposite directions, clockwise for one and counterclockwise for the other. For example, at least one of the inputs comprises an axial segment extending its second segment in a direction opposite to the body of the stator.

Advantageously, the second segments of the inputs are located at an axial end of the first or of the second bun.

Brief description of the figures

Other characteristics and advantages of the invention will emerge clearly from the description given below, by way of indication and in no way limiting, with reference to the appended figures, among which:

FIG. 1 is a view in axial half-section of an alternator according to the invention,

- Figure 2a is a top view of a part of the body of a stator of Figure 1 according to a first embodiment of the invention, Figure 2b being a sectional view of a half stator body according to the arrows Ilb of FIG. 2a, and FIG. 2c a side view along the arrow Ile of FIG. 2a, - FIG. 3 is a view similar to FIG. 2b, for a variant of the first embodiment of the invention ,

FIGS. 4a and 4b are views similar to views 2a and 2b, for another variant of the first embodiment of the invention,

FIG. 5 is a view similar to FIG. 2b, for yet another variant of the first embodiment of the invention, FIGS. 6a and 6b are views similar to views 2a and 2b, for yet another variant of the first embodiment of the invention,

FIG. 7 is a partial view similar to FIG. 2a, for yet another variant of the first embodiment of the invention,

- Figures 8a and 8b are views similar to views 2a and 2b, for a second embodiment of the invention, - Figure 9 is a view similar to Figure 8b, for a variant of the second embodiment of l invention,

FIGS. 10a and 10b are views similar to views 2a and 2b, for a third embodiment of the invention,

FIGS. 11a and 11b are views similar to views 10a and 10b, for a variant of the third embodiment of the invention,

FIGS. 12a, 12b and 12c are views similar to views 2a, 2b and 2c, for a fourth embodiment of the invention,

- Figure 13 is a view similar to Figure 12b, for a variant of the fourth embodiment of the invention, and - Figures 14a and 14b are views similar to views 12a and 12b, for another variant of the fourth mode for carrying out the invention.

In the figures, identical or similar elements will be given the same reference signs.

Description of preferred embodiments of the invention

Figure 1 shows a polyphase rotary electrical machine in the form of an alternator compact with internal ventilation of the three-phase type for motor vehicle with internal combustion engine.

The alternator comprises, going from left to right of FIG. 1, that is to say from front to back, a drive pulley 1 secured, here by means of a nut, of the front end of a shaft 2, the rear end of which carries slip rings (not referenced) belonging to a manifold 3. The axis of the shaft 2 constitutes the axis of rotation of the machine.

Centrally, the shaft 2 supports the rotor 4 with an excitation winding 5, the ends of which are connected by wire connections to the collector 3. The rotor 4 is here a claw rotor and therefore has two pole wheels front and rear 6, 7 each carrying a front fan 8 and rear 9 respectively for, in a given axial size, increasing the power of the alternator and reducing noise thereof. Each wheel 6, 7 is fixed on the shaft 2 provided with knurled portions for this purpose as visible in FIG. 1. Each wheel has a flange perpendicular to the axis of the shaft 2. The excitation winding 5 is installed axially between the flanges of the two wheels 6, 7 shaped to form a cylindrical core for mounting the winding 5. At the outer periphery of the flanges are made of material teeth extending axially. The teeth have a trapezoidal shape and are laterally provided with chamfers. The teeth of one of the wheels are directed towards the other wheel while being angularly offset with respect to the teeth of this other wheel. There is thus nesting of the teeth so that in an alternative embodiment of the permanent magnets are interposed between the two to further increase the power of the machine. For example, profiled grooves are provided in the edges lateral of the teeth to receive the permanent magnets as described in document FR-A-2,748,248. When the winding 5 is activated the rotor 4 is magnetized and pairs of magnetic poles are thus defined, each pole wheel then comprising respectively P / 2 North poles and P / 2 South poles. For more details, see document EP-A-0 515 259; the teeth of the pole wheels having laterally, at their rooting zone at the flange of the pole wheel concerned, each at least one anti-noise chamfer to further reduce the noises, in particular magnetic, of the alternator. Advantageously, each tooth has, relative to an axis of axial symmetry, two anti-noise chamfers. The alternator is therefore less noisy. The fans 8, 9 comprise a first series of blades or blades, which form ventilation channels between them. Advantageously, two series of blades of different length are provided as described in document FR-A-2 811 156. Thus at least one blade of the second series of blades is interposed between two consecutive longer blades of the first series of blades. This arrangement makes it possible to reduce the noises of the alternator while improving the ventilation thereof. The blades are produced by cutting and folding a fixed flange, for example by welding or any other means such as crimping, on the pole wheel 6, 7 concerned. Each wheel has, as mentioned above, axial teeth directed towards the other wheel, with nesting of teeth from one wheel to another for the formation of magnetic poles when the winding 5 is activated by means of the collector rings of the collector 3, each in contact with a brush (not referenced) carried by a brush holder 10 also serving as a support for a voltage regulator (not visible) electrically connected to the brushes to regulate the tension of the winding 5. The regulator is connected to a current rectifying device 11, such as a diode bridge (two of which are visible in FIG. 1), itself connected to the outputs of the phases provided with windings, which the stator 13 of the alternator. The bridge is here of the type described in document EP-A-0 743 738 to which reference will be made for more details. This bridge therefore comprises a positive heat sink on which the positive diodes are mounted, a negative heat sink, on which the negative diodes are mounted, and a connector. Here the negative sink is formed by the flange of the rear bearing 16 of the alternator described below. As a variant, the bridge is of the type described therein in document FR 01 09 482 filed on 07/16/2001. In this case the positive dissipator includes cooling fins, which extend in the radial direction of the alternator; the negative diodes carried by the rear bearing being cooled by convection and conduction. This type of bridge is well suited to the high power alternator according to the invention. The stator 13, forming an armature, surrounds the rotor 4 and has a body 14 internally provided with axial notches 141 for the passage of the wires or pins which comprise the windings. In known manner, the body 14 here consists of a packet of sheets each having notches. These radially oblong notches form grooves when the sheets are aligned and open at the internal periphery of the body 14, in a known manner being semi-closed. The body 14 surrounds the rotor 4 with the presence of a radial air gap between the internal periphery of the body 14 and the external periphery of the rotor 4.

The windings are arranged to form buns 12, 12 'extending, on the one hand, projecting axial on either side of the body 14; and, on the other hand, radially above the fans 8, 9.

These fans 8, 9 extend in the vicinity respectively of a front bearing 15 and a rear bearing 16. The bearings 15, 16 are metallic, being here based on aluminum. These bearings comprise, in known manner, lugs for fixing the alternator to a fixed part of the motor vehicle and electrical connection of the alternator to ground. The bearings 15, 16 are perforated for internal ventilation of the alternator via the fans 8, 9 when the fan assembly 8, 9 - rotor 4 - shaft 2 is rotated by the pulley 1 connected to the engine of the motor vehicle by a transmission device comprising at least one belt engaged with the pulley 1. This ventilation makes it possible to cool the windings of the buns 12, 12 ′ and the winding 5, as well as the brush holder 10 with its tension regulator and the straightening device 11. The arrows followed by the cooling fluid, here air, are shown by arrows in FIG. 1 through the various openings of the bearings 15, 16 and inside the machine. Each bearing thus has a hollow shape and has a flange, here of transverse orientation, having air inlet openings and at the outer periphery of the flange an annular rim of axial orientation provided with air outlet openings located above the buns 12, 12 '.

This device 11, the brush holder, as well as an openwork protective cover (not referenced) and preferably made of plastic, are mounted for fixing by the rear bearing 16 so that the rear fan 9 is more powerful than the front fan 8. In known manner, the bearings 15, 16 are interconnected, here using screws or alternatively by tie rods not visible, to form a casing or support intended to be mounted on a fixed part of the vehicle. This support carries the body 14.

The bearings 15, 16 each carry centrally, by virtue of their flange, a ball bearing 17, 18 for rotationally supporting the front and rear ends of the shaft 2 passing through the bearings to carry the pulley 1 and the collector rings 3. The air inlet openings are delimited by a cylindrical core of axial orientation forming a mounting housing for the ball bearing concerned

The blades of the fans 8, 9 extend radially above the housings presented by the bearings 15, 16 for mounting the bearings 17 and 18, which are thus ventilated. As a variant, the alternator is cooled by a coolant, such as the cooling water of the internal combustion engine of the motor vehicle; the rear bearing comprising channels as described for example in document DE-A-100 19 914 to which reference will be made for more details. The stator is in this case mounted using buffers made of elastic material, for example elastomer, on the casing to filter vibrations and reduce noise. The same is true in FIG. 1, the buffers with a cross-section in the form of a square being not referenced.

These pads intervene between the free ends of the peripheral part in the form of a rim of axial orientation of the bearings and the axial ends facing the body 14. These pads constitute elastic damping means with radial and axial action for mechanical decoupling of the body 14 of the stator relative to the casing constituted by the bearings 15, 16. As a variant, the elastic damping means operate at the level of the notches 141 between the edges of these and the elements electrically conductive, described below, mounted therein as described in document FR 99 16369 filed on 12/23/1999 and published under number FR-A-2 803 126. As a variant of the elastically deformable heat-conductive resin is interposed radially between the external periphery of the body 14 and the internal periphery of one of the bearings, such as the front bearing, as described in the document FR 00 13527 filed on 06/10/2000. In this case the winding 5 of the rotor 4 can be formed from a conductive element wound and coated with a bonding layer, for example of the thermosetting type, as described in document FR-A-2 809 546. The winding 5 gives off more heat which is dissipated by the thermally conductive resin. As a variant, the body 14 is mounted directly on the bearings.

As a variant, the rotor has salient poles as described in document FR 01 00122 filed on 01/05/2001; permanent magnets being received in housings made in the sheet pack that the rotor comprises. These housings are open towards the external periphery of the rotor and axially closed by magnetic parts intended to come into abutment against the magnets.

In FIGS. 2 to 14, the alternator is at least of the three-phase type and comprises at least three phases with, for each of them, an input El to E12 and an output SI to S3 respectively. The outputs, in known manner, are connected to the rectifying device 11 of the electric current knowing that the phases of the stator 13 produce an alternating current when the rotor is excited and is driven in rotation by the vehicle engine via the pulley 1. For this reason it is necessary to rectify the alternating current to supply direct current to the electric consumers of the vehicle and to recharge the battery of this one. The phases are mounted in a star or Y so that in a known manner the inputs are connected to a neutral point.

The alternator can also be hexaphase and therefore comprise, in addition to the first series of three phases, a second series of three phases with, for each of them, an input and an output respectively. These outputs are connected in aforementioned manner to the rectifying device 11, as described for example in the aforementioned document EP-A-0 743 738; the connector of the device 11 comprising lugs for fixing the outputs belonging to a network of electrically conductive pads. The outputs are fixed to the tabs, for example by crimping or welding. In all cases, the alternator comprises a stator 13 provided with a cylindrical body 14 carrying several phases. The body 14 includes notches 141 passing through it parallel to its axis; these notches 141 opening onto an inner face of the body 14 and being regularly distributed along the inner periphery of the body 14.

As specified above, the stator comprises at least three phases in the embodiments of the invention described here. Each phase comprises on the one hand an input E1 to E12 and an output S1 to S3 located at least partially outside the body 14 of the stator 13, and on the other hand electrically conductive elements 50 passing through the body 14 of the stator 13 to form two opposite axial sides thereof first and second buns 12 and 12 '.

The conductive elements 50 are electrically connected together to form at least one winding connecting the phase inputs E1 to E12 to the phase outputs. There is generally one winding per phase. These electrically conductive elements 50 are pins comprising two straight and parallel axial branches 51 and a head 52 having the form of a hanger and connected by two ends opposite the two axial branches 51.

The axial branches 51 of the same conductive element are engaged in notches 141 different from the body 14 of the stator 13, one branch 51 being located towards the outside of the body 14 and the other located towards the inside of the body 14. By moreover, each axial branch 51 is extended on the side opposite to the head 52 by a connection part 511 which is welded to a connection part belonging to the axial branch of another pin 50. Here the branches 51 have in section a shape rectangular. Thus, when the alternator is of the three-phase type, two axial branches 51 are provided by notch 141 as visible in FIG. 5 of document FR-A- 2 818 821. As a variant, as visible in FIG. 9 of document FR-A- 2 818 821, four branches 51 are provided per notch 141, the phases being mounted in a star or Y as in FIG. 7 of this document. The branches 51 are advantageously mounted with radial superposition in each notch 141, here of oblong shape and of radial orientation. The curved heads 52 of the pins 50 all project from the same axial side of the body 14 of the stator 13 and form the first bun 12. They are all parallel to each other and each have in their center an axial vertex 521 situated on the side opposite the body 14. These axial vertices 521 form a circle around the axis of the body 14 and constitute the axial end of the first bun 12.

The connection parts 511 of the pins 50 all project from the axial side of the body 14 of the stator 13 opposite the first bun 12 and form the second bun 12 '.

The inputs E1 to E12 consist of bars having at least one longitudinal flat face 21 to 24 extending along at least a part of the bar, and generally over its whole. The inputs El to E12 and the outputs SI to S3 advantageously have the same section as the bars 51 and are therefore here of rectangular section. More specifically, the inputs E1 to E12 are generally bars of rectangular section, and therefore have two relatively wide opposite flat faces 21 to 24, called flat, and two narrow opposite faces 21 'to 24', called edges, relatively narrower than the flat faces 21 to 24.

Each entry El to E12 includes a first segment

25 passing through the body 14 of the stator 13 and a second end segment 26 to 40 extending on an axial side of this body 14; the second segments 26 to 40 of the inputs E1 to E12 being located on the same axial side of the body 14 of the stator 13 and being electrically connected together to form a neutral point 53.

Each input E1 to E12 also includes a third segment 45 connecting the first and second segments, and a fourth segment 46 extending the first segment 25 on the side opposite to the third segment 45. This fourth segment 46 projects from the axial side of the body 14 of the stator 13 opposite the neutral point 53 and is welded to an electrically conductive element 50 of the phase associated with said input.

According to the invention, the inputs E1 to E12 are twisted, at least one flat face 21 to 24 of each input, generally both, extending along the first segment 25 in a radial plane, and extending along the second end segment 26 to 40 either for forming a portion of cylinder coaxial with the body 14 of the stator 13, or in a plane tangential to a cylinder coaxial with the body 14 of the stator 13.

In the first case, the second segments are of circumferential orientation. In the second case, the second segments are of axial orientation.

The second segments 26 to 40 of the inputs E1 to E12 are in both cases located at an axial end of the first or second bun 12 or 12 '. In the embodiments shown in FIGS. 2 to 14, these second segments 21 to 24 extend more precisely along the circle drawn by the vertices 521 of the curved heads 52.

The change of orientation of the flat faces 21 to 24 is carried out gradually along the third segment 45 of each entry, which connects the first segment 25 to the second segment.

Note that the first segment 25 of the inputs

E1 to E12 is exactly parallel to the axial branches 51 of the conductive elements 50, and that the third segment 45 is substantially parallel to a curved head half 52.

In a first embodiment of the invention shown in Figures 2 to 7, at least two of the second segments 26 of the inputs El to E3 are identical.

In a first alternative embodiment shown in FIGS. 2a to 2c, the second segments 26 of the three inputs El to E3 are of circumferential orientation and extend in the same direction, which is the clockwise direction in FIG. 2a. The second segments 26 of the inputs E1 and E2 have substantially the same circumferential length greater than that of the second segment 26 of the input E3.

The input E2 is arranged between the inputs El and E3 following the circumference of the body 14, the inputs El and E2 being separated by the same angular offset as the inputs E2 and E3.

The second segment of the input El is located slightly more outside the body 14 than the second segment of the input E2, which is itself located slightly more outside the body 14 than the second segment of 1 'input E3.

If the front and end part 261 and 262 are called the parts of the second segment 26 situated respectively relatively close to and opposite the third segment 45, it will be noted in FIG. 2a that the end part 262 of the second segment 26 of the input El is pressed along the front part 261 of the second segment 26 of the input E2. Likewise, the end part 262 of the second segment 26 of the input E2 is pressed along the front part 261 of the second segment 26 of the input E3. The second segments of the inputs El and E3 do not meet.

The second segments of the inputs E1 to E3 are pressed against each other by their respective relatively wide flat faces 21.

The second segment 26 of the input El is welded by a free end 263 to the second segment 26 of the input E2, at a relatively central point therein.

The second segment 26 of the input E2 is welded by its free end 263 to the free end 263 of the second segment 26 of the input E3.

Thus, the second segment 26 of the input E3 does not extend clockwise beyond the point of welding with the input E2.

In the second variant, the second segment 26 of the input E3 extends clockwise beyond the welding point with the input E2 as visible in FIG. 3. In yet a third alternative embodiment, shown in FIG. 3, the second segment 26 of the inlet E2 extends beyond the weld point with the inlet E2 also by an axial segment 56 on the side opposite to the third segment 45 , this axial segment 56 extending in a direction opposite to the body 14 of the stator 13. In these three variants, three inputs and two welds are used. As a variant, three welds and an additional neutral bar are used to reduce the circumferential length of the inputs.

Thus, in a fourth alternative embodiment, represented in FIGS. 4a and 4b, the second segments 27 of the inputs El to E3 are electrically connected by a neutral bar 54 of circumferential orientation, the second segments 27 of the inputs being fixed on this bar neutral by their respective flat faces 21.

This neutral bar 54 has a rectangular section identical to the section of the inputs El to E3, and therefore also includes two opposite flat faces 21.

The neutral bar 54 is arranged so that its flat faces 21 form portions of cylinder coaxial with the body 14.

The second segments 27 of the inputs El to E3 are also of circumferential orientation, their respective flat faces 21 forming portions of cylinder coaxial with the body of the stator, the second segments 27 of the three inputs El to E3 being pressed along the flat face 21 of the most radially inner neutral bar 54.

These second segments 27 are welded by free ends 271 to the neutral bar 54. The second segments 27 of the inputs El to E3 are here circumferentially of the same length, therefore identical. The same is true in Figures 4 to 7.

The second segments 27 are arranged in the extension of each other, parallel to the neutral bar 54, but do not touch. The neutral bar 54 practically does not protrude on each side of the three second aligned segments 27.

The inputs El, E2 and E3 are regularly spaced around the axis of the body 14. As a variant, at least one of the second segments 27 is circumferentially of different length.

A fifth alternative embodiment is shown in FIG. 5. It is identical to the fourth alternative embodiment in all points, with the exception of the neutral bar 54, which is extended at one of its ends 541 by a segment of axial orientation 56 extending in a direction opposite to the body 14 of the stator 13. A sixth alternative embodiment is shown in FIGS. 6a and 6b. It is identical to the fifth embodiment except that the second segments 27 of the inputs El to E3 extend in an axial and non-circumferential direction, their respective flat faces 21 extending in planes tangent to the neutral bar 54. The circumferential lengths of the inputs are therefore reduced.

The second segments 27 of the inputs E1 to E3 can be fixed by their respective flat faces on the flat face 21 of the neutral bar 54 located radially the most inside the body 14, as in FIG. 6a or the most outside of the body 14, as in FIG. 7. This first embodiment is therefore particularly simple since the three inlets are of the same type because they extend in the same circumferential direction, at least two being identical, except in the variants where one of the inlets is extended by an axial segment . It is thus possible to limit the number of different coins put into play, which is practical and economical.

A second embodiment of the invention is shown in FIGS. 8 and 9. In this mode, two welds are used and a first entry of great circumferential length. Thus a first entry E4 comprises a second segment 28 relatively long in circumferential orientation, two other entries E5 and E6 comprising second segments 29 of the same length relatively shorter than the length of the second segment 28 of the first entry E4.

The two flat faces 22 of the second segment 28 of the first inlet E4 form portions of coaxial cylinders with the body 14 of the stator 13, the second segments

29 of the two other inputs E5 and E6 being fixed by their respective flat faces 22 on one of the two flat faces 22 of the second segment 28 of the first input E4.

The other inputs E5 and E6 are arranged on the same side of the first input E4 following the circumference of the body 14, the second segment 28 of the first input E4 extending in the direction of these inputs E5 and E6.

In the first alternative embodiment, represented in FIGS. 8a and 8b, the second segments 30 and 31 of the two other inputs, E5 and E6 respectively, are of circumferential orientation and extend in opposite directions, clockwise for one and counterclockwise for the other by following the periphery of the body 14 of the stator 13 The respective flat faces 22 of the second segments 30 and 31 of the two other inputs E5 and E6 form portions of coaxial cylinders with the body 14 of the stator 13. These flat faces 22 extend parallel to one of the two flat faces 22 of the second segment 28 of the first input E4, over their entire length or at least by an end portion 221, and are pressed against said flat face 22 of the second segment 28. The second segments 30 and 31 of the other two inputs E5 and E6 are welded by respective free ends 301 and 311 on the second segment 28 of the first input E4.

An alternative embodiment, not shown, is identical to the first except that the second segments 30 and 31 belonging respectively to the inputs E5 and E6 extend in the same direction. This direction can be indifferently identical to the direction in which the second segment 28 of the first input E4 extends or opposite to it. Their respective flat faces 22 form portions of cylinder coaxial with this body 14.

A third variant is identical to the first or the second variant, but the second segment 28 of the first inlet E4 is extended by an axial segment 56 extending in a direction opposite to the body 14 from the end of the second segment 28 opposite the third segment 45. It is shown in Figure 9. Of course it is possible to reduce the number of welds and simplify the entries.

Thus in a third embodiment of the invention, shown in FIGS. 10 and 11, two of the inputs, E7 and E8, are joined by their second respective segments 32 and 33 to constitute the two branches of a pin 55.

These respective second segments 32 and 33 are of circumferential orientation, and extend in opposite directions, one clockwise and the other counterclockwise following the circumference of the body 14. Their respective flat faces 23 are arranged in the extension of each other. These flat faces 23 together form a continuous portion of cylinder coaxial with the body 14 of the stator 13 so that the inputs E7 and E8 are simplified.

A third inlet E9 is fixed by the flat face 23 of its second segment 34/35 to said cylinder portion formed by the flat faces 23 of the second segments 32 and 33 of the inputs E7 and E8.

In a first alternative embodiment, represented in FIGS. 10a and 10b, the inputs E7 to E9 are located at different angular positions around the axis of the body 14 of the rotor 13, the two inputs E7 and E8 joined in a pin shape being consecutive following the periphery of the stator body. The input E9 is here of greater circumferential length than that of the inputs E7, E8 combined,

The second segment 34 of the third inlet E9 is of circumferential orientation, its opposite flat faces 23 forming portions of cylinders coaxial with the body 14 of the stator 13.

This second segment 34 comprises an end portion 341 which extends parallel to the second joined segments 32 and 33 of the inputs E7 and E8 and is pressed by one of the two flat faces 23 on one of the two opposite flat faces 23 of the second joined segments 32 and 33. The end part 341 of the second segment 34 is welded at a point on the second joined segments 32 and 33, for example by a free end 342.

A second alternative embodiment is shown in Figures 11a and 11b. It is identical to the first variant, except for the following points.

It will first be noted that the two inputs E7 and E8 joined in a pin are not consecutive by following the periphery of the body 14 of the stator 13. The third input E9 is interposed between the inputs E7 and E8.

It will also be noted that the second segment 35 of the third input E9 extends in an axial direction, one of its opposite flat faces 23 extending in a plane tangent to the second segments 32 and 33 joined together of the two inputs E7 and E8 forming a pin.

This second segment 35 is welded at a point on the second joined segments 32 and 33, for example by a free end 351. A third variant is identical to the first or the second variant, but the second segment 34/35 of the third entry E9 is extended by an axial segment 56 extending in a direction opposite to the body 14 from the end of the second segment 34/35 opposite to the third segment 45.

It should be noted that the characteristics of the first and second variants can be combined without departing from the invention. It is thus possible to associate inputs E7 and E8 consecutive with a third input E9 whose second segment is of axial orientation. Likewise, non-consecutive inputs E7 and E8 can be associated with a third input E9, the second segment of which is of circumferential orientation.

In a fourth embodiment of the invention illustrated in FIGS. 12 to 14, the second segments 36 to 40 of the inputs E10 to E12 are of circumferential orientation and all extend in parallel over at least part of their length. In this embodiment there is only one welding point for the three inputs.

In a first alternative embodiment shown in FIGS. 12a, 12b and 12c, the second segments 36 to 38 belonging respectively to the inputs E10 to E12 all extend in the same direction, for example clockwise, following the circumference of the body 14 of the stator 13 shown in FIG. 12a.

The inputs E10 to E12 are located at different angular positions around the axis of the body 14, E10 preceding Eli, which itself precedes E12 when the circumference of the body 14 is followed in FIG. 12a clockwise.

The length of the second segment 36 is greater than that of the second segment 37, which is itself greater than that of the second segment 38, the respective free ends 361, 371 and 381 of these three segments arriving at the same point.

The respective flat faces 24 of the second segments 36 to 38 form portions of coaxial cylinders with the body 14 of the stator 13. The second segment 38 of the input E12 is pressed over its entire length, by one of its flat faces 24, on a flat faces 24 of the second segment 37 of the entrance Eli.

Likewise, the second segment 37 of the input Eli is pressed over its entire length, by its flat face 24 opposite to the second segment 38, on one of the flat faces 24 of the second segment 36 of the input E10.

The free ends 361 to 381 of the second segments 36 to 38 are welded together. In a second alternative embodiment, represented in FIGS. 14a and 14b, the respective second segments of at least two of the ElO inputs to E12 extend in opposite directions, for example clockwise for the second segments 36 and 39 of the ElO inputs and Eli and anti-clockwise for the second segment 40 of the input E12, following the circumference of the body 14 shown in FIG. 14a.

The inputs ElO to E12 are located at different angular positions around the axis of the body 14, ElO preceding Eli, which itself precedes E12 when the circumference of the body 14 is followed in FIG. 14a.

The length of the second segment 36 of the ElO input is greater than that of the second segment 39 of the Eli input. The respective free ends 361, 391 and 401 of the three segments 36, 39 and 40 arrive at the same point.

The respective flat faces 24 of the second segments 36, 39 and 40 form portions of coaxial cylinders with the body 14 of the stator 13.

The second segment 39 of the Eli input is pressed over its entire length, by one of its flat faces 24, on one of the flat faces 24 of the second segment 36 of the ElO input. On the other hand, the second segment 40 of the input E12 is pressed only by the face 24 of its free end 401, on the flat face 24 of the second segment 36 of the input ElO opposite the second segment 39.

The free ends 361, 391 and 401 of the second segments 36, 39 and 40 are welded together.

A third alternative embodiment is identical in all respects to the first or second alternative embodiment, except that the second segment 36 of the ElO input is extended by an axial segment 56 extending in one direction opposite to the body 14 from the end of the second segment 36 opposite the third segment 45. An exemplary embodiment of this third variant is shown in FIG. 13. It will therefore be understood that the various embodiments of the invention described here -above allow easy welding of the second segments of the three inputs one on the other, the welding head being positioned radially relative to the stator body. Indeed, the flat faces, here relatively wide, that is to say the flat ones, of the second segments always extend in planes perpendicular to a radial direction relative to the cylindrical body of the stator.

The invention has been described in its application to a three-phase stator, but can be applied to a stator comprising six or even phases.

Entrances may have non-rectangular sections, provided that each entrance has at least one flat longitudinal face. It will be noted that the neutral point is formed by making a small number of welds, from 1 to 3 depending on the embodiments and variants.

In the illustrated figures there are actually provided four conductive elements by axial notches 141 and two series of three-phase winding offset by an electrical angle of 30 ° as visible for example in Figures 3 and 4 of document FR-A- 2 819 117 filed 10/19/2001. The heads of the pins connect the axial branches as for example in FIGS. 7, 15 and 16 of this document to which reference will be made for more details. In the notches the conductors the first segments 25 are in contact by their relatively wide flat faces with the generally radial edges of the notches. In variants the notches 141 are inclined so that in all cases the flat face of each entry extends along the first segment in a generally radial plane. In variants, notches are not provided as described for example in document US-A-5,097,167 to which reference will be made for more details. Insulating plates and resin elements are thus provided at the ends of the buns. The first segments 25 pass through the body of the stator in all cases.

Claims

1. Alternator, in particular for a motor vehicle, comprising a stator (13) provided with a body

(14) cylindrical carrying several phases (P), each phase comprising on the one hand an inlet (El to E12) and an outlet (SI to S3) located at least partially outside the body (14) of the stator ( 13), and on the other hand electrically conductive elements (50) passing through the body (14) of the stator (13) to form two opposite axial sides thereof of the first and second buns (12, 12 '), the conductive elements (50) being electrically connected together to form at least one winding connecting the phase inputs to the phase outputs, the inputs (El to E12) being made up of bars having at least one longitudinal flat face (21 to 24) s 'extending along at least part of the bar, each inlet comprising a first segment (25) passing through the body (14) of the stator (13) and a second end segment (26 to 40) extending from an axial side of this body (14), the second segments (26 to 40) of the inlets (El to E12) being located ues on the same axial side of the body (14) of the stator (13) and being electrically connected together to form a neutral point (53), characterized in that the inputs (El to E12) are twisted, the flat face ( 21 to 24) of each entry (El to E12) extending along the first segment

(25) in a generally radial plane, and extending along the second end segment (26 to 40) either to form a portion of cylinder coaxial with the body (14) of the stator (13), or in a tangential plane to a cylinder coaxial with the body (14) of the stator (13).

2. Alternator according to claim 1, characterized in that the second segments (26, 27) of the inputs (El, E2, E3) are identical.

3. Alternator according to claim 2, characterized in that the second segments (27) of the inputs (El, E2, E3) are electrically connected by a neutral bar (54) of circumferential orientation, the second segments (27) of the inputs (El, E2, E3) being fixed on this neutral bar (54) by their respective flat faces (21).

4. Alternator according to claim 3, characterized in that the second segments (27) of the inputs (El, E2, E3) are of circumferential orientation, their respective flat faces (21) forming portions of cylinders coaxial with the body (14 ) of the stator (13).

5. Alternator according to claim 3, characterized in that the second segments (27) of the inputs (El, E2, E3) extend in an axial direction, their respective flat faces (21) extending in planes tangent to the neutral bar (54).

6. Alternator according to claim 1, characterized in that a first input (E4) comprises a second segment (28) relatively long in circumferential orientation, two other inputs (E5, E6) comprising second segments (30, 31) of the same length relatively shorter than the length of the second segment (28) of the first inlet (E4), the flat face (22) of the second segment (28) of the first inlet (E4) forming a portion of cylinder coaxial with the body

(14) of the stator (13), the second segments (30, 31) of the two other inputs (E5, E6) being fixed by their respective flat faces (22) on the flat face (22) of the second segment (28) of the first entry (E4).

7. An alternator according to claim 6, characterized in that the second segments of the two other inputs (E5, E6) are of circumferential orientation and extend in the same direction, clockwise or counterclockwise, their flat faces (22) respective forming portions of coaxial cylinders to the body (14) of the stator (13).

8. An alternator according to claim 6, characterized in that the second segments (30, 31) of the other two inputs (E5, E6) are of circumferential orientation, and extend in opposite directions, clockwise for one and counterclockwise for the other, their respective flat faces (22) forming portions of cylinders coaxial with the body (14) of the stator (13).

9. Alternator according to Claim 1, characterized in that two inputs (E7, E8) are joined by their respective second segments (32, 33) to constitute the two branches of a pin (55), these second segments (32, 33) respective being of circumferential orientation, the respective flat faces (23) of these two second segments (32, 33) being arranged in the extension of one another and forming a portion of cylinder coaxial with the body (14) of the stator (13), a third inlet (E9) being fixed by the flat face (23) of its second segment (34, 35) to said portion of cylinder.

10. An alternator according to claim 9, characterized in that the inputs (E7, E8, E9) are located at different angular positions around the axis of the body (14) of the rotor (13), the two inputs (E7, E8) joined as a pin being consecutive following the periphery of the body (14) of the stator (13).

11. Alternator according to claim 9, characterized in that the inputs (E7, E8, E9) are located at different angular positions around the axis of the body (14) of the rotor (13), the two inlets (E7, E8) joined in a pin shape are not consecutive following the periphery of the body (14) of the stator ( 13).

12. Alternator according to any one of claims 9 to 11, characterized in that the second segment (34) of the third inlet (E9) is of circumferential orientation, its flat face (23) forming a portion of cylinder coaxial with body (14) of the stator (13).

13. An alternator according to claim 9, characterized in that the second segment (35) of the third inlet (E9) extends in an axial direction, its flat face (23) extending in a plane tangent to the second joined segments (32, 33) of the two inputs (E7, E8) forming a pin.

14. An alternator according to claim 1, characterized in that the second segments (36 to 40) of the inputs (ElO, Eli, E12) are of circumferential orientation and all extend in parallel over at least part of their length.

15. An alternator according to claim 14, characterized in that the second segments (36, 37, 38) of the inputs (ElO, Eli, E12) all extend in the same direction, clockwise or counterclockwise.

16. Alternator according to Claim 14, characterized in that the respective second segments (39, 40) of at least two inputs (Eli, E12) extend in opposite directions, clockwise for one and counterclockwise for the other.

17. Alternator according to claim 1, characterized in that at least one of the inputs (El to E12) comprises an axial segment (56) extending its second segment (26 to 40) in a direction opposite to the body (14) of the stator (13).

18. Alternator according to any one of claims 1 to 17, characterized in that the second segments (26 to 40) of the inputs (El to E12) are located at an axial end of the first or of the second bun

(12, 12 ').