FR3054741A1 - ROTATING ELECTRIC MACHINE PROVIDED WITH A STATOR WITH A PIPE WINDING - Google Patents

Abstract

A rotating electrical machine comprising: a rotor rotating about an axis a stator surrounding said rotor, the space between the rotor and the stator defining an air gap of the machine, the stator including notches (103), each of the notches comprises locations (108, 109) for receiving pins, wherein for each notch (103), said locations (108, 109) are aligned such that only one said low location (108) is contiguous with the air gap and at least one other high location (109) is not contiguous with the air gap, said top and bottom locations (108, 109) each receiving a pin arm with an insertion set. It is expected that the notch (103) is trapezoidal so that the insertion play of the at least one top location (109) of the notch is greater than the insertion set of the bottom location (108). of the notch.

Description

Holder (s): VALEO ELECTRIC EQUIPEMENTS MOTOR Simplified joint-stock company.

Extension request (s)

Agent (s): VALEO EQUIPEMENTS ELECTRIQUES MOTOR Simplified joint-stock company.

ROTATING ELECTRICAL MACHINE PROVIDED WITH A STATOR WITH A SPINDLE COIL.

FR 3 054 741 - A1 (5 /) Rotating electric machine comprising:

-a rotor rotating around an axis

a stator surrounding said rotor, the space between the rotor and the stator defining an air gap of the machine, the stator comprising notches (103), each of the notches comprises locations (108, 109) for receiving pins, in which for each notch (103), said locations (108, 109) are aligned so that only one location called bottom location (108) is contiguous to the air gap and at least one other location said top (109) is not contiguous of the air gap, said top and bottom locations (108, 109) each receiving a pin branch with an insertion clearance.

It is provided that the notch (103) is trapezoidal so that the insertion clearance of the at least one high location (109) of the notch is greater than the insertion clearance of the low location (108) of the notch.

ROTATING ELECTRICAL MACHINE PROVIDED WITH A STATOR WITH A PIN PACKAGE

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a rotary electrical machine provided with a stator with a pin winding, the electrical machine being able to operate, for example, reversibly in motor mode and in alternator mode.

TECHNOLOGICAL BACKGROUND

In known manner, rotary electrical machines comprise two coaxial parts, namely a rotor and a stator surrounding the rotor body.

In known manner, rotary electrical machines comprise two coaxial parts, namely a rotor and a stator surrounding the rotor.

Referring to Figure 1, there is shown an example of such a rotary electrical machine referenced 100, in the case of an alternator with internal ventilation of the polyphase type for a motor vehicle with thermal 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 internal combustion engine of the vehicle as described in document FR A 2 745 445 for propelling the motor vehicle.

When the machine 100 operates in alternator mode it transforms mechanical energy into electrical energy like any alternator. When the machine operates in electric motor mode, in particular in starter mode to start the vehicle thermal engine, it transforms electrical energy into mechanical energy.

This machine 100 essentially comprises a casing 1 and, inside of it, a rotor 2 integral in rotation with a central shaft 3, called the rotor shaft, and a stator 50 of annular shape, which surrounds the rotor 2 with the presence of an air gap 110 and which comprises a body 4 in the form of a pack of sheets provided with notches, for example of the semi-closed type, for mounting a stator winding 5 forming on either side another of the stator body 4 50, at each axial end thereof, a front bun 51 and a rear bun 53 which are axially projecting.

In other words, the rotating electric machine includes:

-a rotor 2 rotating around an axis X

a stator 50 surrounding said rotor 2, the space between the rotor 2 and the stator 50 defining an air gap 110 of the machine and the notches of the stator 50 are for example open on the side of the air gap.

This coil 5 comprises for example a set of three-phase star or triangle windings, the outputs of which are connected to a rectifier bridge, partially visible at 52, comprising rectifier elements such as diodes or transistors of the MOSFET type, in particular when the machine consists of an alternator-starter.

For example, the windings of the winding 5 are obtained using a continuous wire, electrically conductive, coated with an electrically insulating layer, such as enamel, and mounted in the relevant notches of the body 4 of the stator 50 via notch insulators (not visible).

It can also be provided that the winding 5 includes pins also called conductor or u-pin segment in English terms well known to those skilled in the art.

According to a variant, the winding 5 comprises two sets of three-phase windings to form a device for composite stator windings, the windings being offset by thirty electrical degrees as described for example in documents US-A1-2002 / 0175589, and FR -A-2,784,248. In this case two rectifier bridges are provided and all combinations of three-phase star and / or triangle windings are possible. As a variant, the stator winding is of the five-phase type.

In general, the alternator is of the polyphase type and the rectifier bridge (s) make it possible in particular to rectify the alternating current produced in the windings of the stator 50 with direct current in particular for charging the battery of the motor vehicle and supplying the loads and the electrical consumers in the on-board vehicle network.

The rotor 2, of annular shape, is produced in the example shown in the form of a claw rotor, as described for example in documents US-A1 -2002/01 75589, comprising two pole wheels 7,8 here axially juxtaposed and each having a transverse annular 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 the presence of a chamfer between the tooth and the rooting section.

An annular air gap 110 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 in shape. 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 into the space existing between two adjacent teeth of the other wheel 8, 7 so that the teeth of the wheels 7, 8 are nested. For more details, see document EP 051 5 259.

An excitation winding 10 is installed axially between the flanges of the wheels 7, 8. It is carried by a rotor part 2 in the form of an annular cylindrical core coaxial with the shaft 3. The core of FIG. 1 is constituted of two axially distinct sections, each of which is produced integrally with an associated polar wheel 7,8. According to a variant not shown, the central core consists of a single piece and it is distinct from the pole wheels 7, 8 which are arranged axially on either side of the core.

The winding 10 is therefore located in the space radially delimited by the claws 9 of the wheels 7,8 and the central core.

The wheels 7, 8 and the core are preferably made of ferromagnetic material and are traversed coaxially 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 of the wheels 7, 8 so that it cuts grooves through its knurled portions. The shaft 3 is thus integral in rotation and axially with the wheels, a spacer, not referenced, being interposed between the wheel 7 and a bearing 19 described below.

The axis of the shaft 3 constitutes the axis X of the machine. The winding wire 10 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 10 is activated, that is to say electrically powered, the wheels 7, 8 and the core are magnetized and the rotor 2 becomes an induction rotor with the formation of magnetic poles at the claws 9 of the wheels 7, 8.

This inductor rotor 2 creates an alternating induced current in the stator 50 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 12 belonging to a movement transmission device by means of at least one belt (not shown) between the alternator and the engine of the motor vehicle. This shaft carries at its rear end slip rings connected by wire connections (not shown) at the ends of the excitation winding 10 of the rotor 2.

As a variant, 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 by the reference 14 and they are arranged so as to rub on the slip rings 13, in order to supply the winding 10 with electric current. The brush holder 14 is connected to a voltage regulator (not shown).

The casing 1 in which the rotor 2 and the stator 50 are placed here is in two parts, namely a front flange 16 adjacent to the pulley 12 and a rear flange 17 carrying the brush holder 14 and most often the bridge (s) rectifiers and voltage regulator. The annular flanges 16, 17, for example based on aluminum, are hollow in shape and each carry a central ball bearing 19 and 20 respectively for the rotational mounting of the shaft 3 of the rotor 2. The flanges are assembled together using tie rods or screws as visible for example in Figure 1 of the aforementioned document EP 0515 259. In other words, the casing 1 of the machine 100 comprises the front flange 16 also called the front bearing and the rear flange 17 also the rear bearing.

As illustrated in FIG. 1, it is possible to provide, at the external periphery of the body 4 of the stator, in the form of a sheet bundle, an elastic system for filtering vibrations, with a flat seal at the front 40 and at the rear of the pads 41, flexible and thermally conductive resin being interposed between the front flange and the stator body to dissipate the heat.

As 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 in rotation by the casing 1 via the bearings 19, 20.

As a variant, the casing is in three parts, the flanges 16, 17 being arranged on either side of a central part carrying the stator body. The flanges are assembled to the intermediate part, for example by screwing.

The alternator also includes means for cooling it. To this end, in FIG. 1, the flanges 16, 17 are perforated to allow cooling of the alternator by air circulation and the rotor 2 carries at least at one of its axial ends a fan intended to ensure this air circulation. Here a first fan 23 is provided on the front end face of the rotor 2 and a second fan 24, on the rear face of the rotor 12. Each fan 23, 24 is of annular shape 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 of the centrifugal or helico-centrifugal type.

With reference to FIG. 1, the air is sucked in through openings 60 of the front flange surrounding the pulley 12 at the front of the flange, then is mainly ejected centrifugally by the blades 26 and passes into the space between the front bun 51 and the front flange 16 to cool the front bun and finally exit through openings 61 on the external radial periphery of the front flange. The rear flange 17 also has a plurality of air inlet and outlet ports.

In FIG. 1, the brush holder 14 and the tension regulator, integral with the flange 17, are capped by a cover 70, integral with the rear flange 17 while being fixed here on the latter by snapping onto studs 71 integral with the flange back. This cover 70 also has air intake orifices, not visible in FIG. 1.

Figures 2 to 7 show in more detail the stator 50 comprising the winding 5 when the winding comprises pins.

As can be seen in FIG. 2, the stator 50 comprises a stator body 4 and a coil 5 formed of pins of which only 2 are illustrated here, namely the two pins 101 and 102 which are found in a notch 103. More specifically, each of the two pins 101 and 102 comprises two pin branches 101 a and 101 b on the one hand and 102a and 102b on the other hand and in the notch 103 there is a branch of each of these two pins 101b and 102a.

Figure 3 illustrates in more detail the notch 103 of the stator 50 before the introduction of the pins. This notch 103 is delimited by two teeth 106 located on either side of the notch 103 and includes a notch opening 107 located on the side of the air gap 110 of the electric machine 100. The notch opening 107 is necessary to avoid any short circuit between the two adjacent teeth 106.

The notch 103 includes locations 108 and 109 for receiving pins 101 and 102. The locations 108, 109 are aligned for example radially so that only one location called bottom location 108 is contiguous with the air gap 110 and at least one other said top location 109 is not contiguous with the air gap 110. The top and bottom locations 108, 109 are each intended to receive a pin branch.

The notch 103 comprises two substantially radial direction edges 105a and 105b as well as two substantially ortho radial direction edges 105c and 105d, the edge 105d being located on the side of the notch opening 107. It is intended that the two edges 105a and 105b are parallel. This is called a notch with parallel edges.

Figure 4 illustrates in more detail the notch 103 of the stator 50, it differs from Figure 3 in that the notch is now provided with the two pin branches 101b and 102a, the branch 101b being received in the location 108 and the branch 102a being received in the location 109. The pin branches 102a and 101b have a section whose two sides which are substantially radially oriented are parallel. We then speak of a branch of pins with parallel sides.

Furthermore, with reference to FIG. 2, it appears that for the pin 101, the other branch 101a is in a high location 109 while for the pin 102, the other branch 102b is in a low location.

In other words, for each pin 101, 102 having a branch received in a low location, its other branch is received in a high location of another notch.

The stator 50 comprises an insulator 104 which covers the edges of at least one notch. In this case the insulator 104 covers here two radial edges 105a and 105b as well as two ortho radial edges 105c and 105d of the notch, the edge 105d being situated on the side of the notch opening 107.

In addition, as can be seen in Figure 4, it can be an insulator 104 in the form of S which is recognizable in that it extends between the two branches 101b and 102a in the notch. Alternatively, another type of O-shaped insulation could be provided.

However, when inserting the pins into the stator body 4, it may happen that the insertion is problematic. By problematic insertion is meant an insertion according to which there is a collision between the pin branch and the insulator which can cause a tearing off or an axial displacement of the insulator, an impossibility of fitting the pin branches , or an injury of the branches of pins or of the insulator, the injury of the branches of pins being able to cause a removal of an electrically insulating enamel from said branches. This is problematic because the insulator on the one hand and the email of the pin on the other hand are intended to prevent any electrical contact between the stator body and the pins. Thus, their injury can cause a short circuit of the stator which makes the entire electric machine unusable.

To avoid this, provision can be made, as illustrated in FIG. 4, for each of the two branches to be received in its respective location with a clearance for inserting the notch 103.

The insertion clearance for the notch 103 corresponds to half of the difference between a distance 111 between the two radial edges 105a and 105b after they are covered with the insulation 104 and a width in section 112 of the branches d received pin. For example, the width in section is measured along a plane perpendicular to the X axis and in a substantially ortho radial direction, similarly the distance between the two radial edges is measured along a plane perpendicular to the X axis and in a direction substantially ortho radial. In other words, the insertion clearance corresponds to a distance measured between the pin branch and the edge covered with the insulation.

The insertion set allows a margin which compensates for possible defects in the pins or notches and thus avoids problematic insertion. For example, if the width in section 112 of a pin branch is greater than the nominal values or if the distance between the two radial edges of the notch is smaller than the nominal values then the presence of the play of insertion will compensate for faults to avoid problematic insertion.

It is possible, as illustrated in FIG. 4, to provide a uniform clearance based on the fact that the branches of pins are perfectly parallel to the edges of the notches, these clearances between the branch of pins and the radial edges covered with the insulation. are for example of the order of 0.1 mm on either side of the pin branch. These uniform clearances form empty spaces which can occupy 10% of the notch surface which is for example 10mm x 2.5 mm.

FIG. 5 illustrates in detail a notch 103 of the stator. This notch 103 differs from that illustrated in FIG. 4 in that the notch includes 4 locations for receiving pins. More specifically, the notch 103 includes a bottom location 108 and three top locations 109 to each receive a pin branch.

FIG. 6 illustrates in detail a notch 103 of the stator. This notch 103 differs from that illustrated in FIG. 4 in that the two branches 101b and 102a are inclined in their respective locations 108 and 109. It is an inclination which can be more or less pronounced during the insertion of the pins into the stator body 4.

FIG. 7 illustrates in detail a notch 103 of the stator. This notch 103 differs from that illustrated in FIG. 4 in that the two branches 101b and 102a are offset in their respective locations 108 and 109. This is an offset which can be more or less pronounced during the insertion of the pins into the stator body 4.

The uniform play as shown in FIG. 4 assuming that the branches of pins are perfectly parallel to the edges of the notches does not correspond to reality and it appears that with a uniform insertion play of the order of for example 0.1 mm on both sides of the pin branch, it is not possible, in particular in the high locations, to avoid collision during the insertion of the pin branches when the latter are offset or inclined. Indeed, it appears that the inclinations and offsets illustrated in FIGS. 6 and 7 imply collisions between the branches of pins and the insulation.

In addition, if sufficient uniform insertion clearance is provided to compensate for inclination or offset as illustrated in FIG. 6 or 7, it would be very important so that the occupied surface of the notch would be greatly reduced. This is also detrimental because then the resistance of the winding increases which increases the joule losses and reduces the efficiency of the machine.

There is therefore a need for a dimensioning of the stator making it possible to avoid the collision between the insulator or the notch and the pin branch while maintaining a large occupied notch surface.

OBJECT OF THE INVENTION

The object of the invention is to respond to this wish while remedying at least one of these aforementioned drawbacks.

According to the invention, a rotary electrical machine is proposed comprising:

-a rotor rotating around an X axis

a stator surrounding said rotor, the space between the rotor and the stator defining an air gap of the machine, the stator comprising notches, each of the notches comprises locations for receiving pins, in which for each notch, said locations are aligned so that only one location called the bottom location is contiguous to the air gap and at least one other location called the top location is not contiguous to the air gap, said top and bottom locations each receiving a pin branch with a set of insertion.

According to a general characteristic, the notch is trapezoidal so that the insertion clearance of the at least one top location of the notch is greater than the insertion clearance of the bottom location of the notch.

Indeed, the constraints on the insertion clearance are greater on the high locations of the notch. This is notably due to the fact that for a given notch, the pin branch of the top location is the last inserted. Thus, with a trapezoidal notch shape, it is possible with respect to a notch with parallel edges to obtain, for a lesser or even identical insertion clearance at the bottom location, a greater insertion clearance at the high location level.

We can therefore reduce the insertion clearance at the bottom location without increasing the overall insertion constraints. In addition, this reduction in the insertion clearance allows an increase in the size of the teeth, which makes it possible to limit the saturation of the teeth and a greater increase in flow.

This is all the more interesting since the lower part of the teeth acts as a bottleneck for this rise in flow. Thus, by increasing the size of the teeth in this part, it is easy to increase the amount of flow collected. In other words, for a given tooth if we consider its width with a substantially ortho-radial direction and its length with a radial direction, the amount of flow raised depends directly on the minimum width of the tooth over all its length.

According to the state of the art with parallel notches, the minimum width of the tooth was located at the notch opening just below the tooth feet. If we increase the width of the teeth at this location, we are therefore sure to increase the minimum width, which allows more flow to go up even if other sectors of the tooth have a narrower width compared to the state of technique.

According to other characteristics taken individually or in combination:

the stator comprises teeth defined between two adjacent notches, said teeth being with parallel sides. By using a tooth with parallel sides, one avoids the phenomenon of bottleneck which limits the magnetic flux to the section according to a plane perpendicular to the smallest radius of the tooth. In particular, in the case of a tooth having a trapezoid shape when one moves from the air gap to the cylinder head of the stator, the flow is limited by the section of the tooth closest to the air gap.

-the insertion clearance of a low location is less than 0.1 mm.

the stator comprises an insulator, said insulator covering the edges of at least one notch. The insertion clearance is thus defined between the edge of the notch covered with the insulation and the conductor.

the insulator is an S insulator.

-each notch includes four locations to receive four pin branches.

- For each notch, at least one pin branch having a section in a plane perpendicular to the axis X, said section comprises sides oriented substantially radially which are parallel.

the pin branch received in a low location is stamped so that its section in a plane perpendicular to the axis X has a trapezoidal shape corresponding to the trapezoidal shape of the notch. In fact, due to the lower insertion constraints on the low location 108, the space available at the low location is not useful. It is thus possible to increase the width of the branch section and thus reduce its length in order to give more space in length to the pin branch 102a in the high location 109. This allows for better occupancy of the 'notch and therefore a reduced winding resistance.

for each pin having a branch received in a bottom location of a notch, its other branch is received in a top location of another notch.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figure 1 shows a sectional view of a rotary electrical machine in the form of an alternator according to the prior art;

2 shows a top view of the stator of the electric machine of Figure 1 according to the prior art;

Figure 3 shows a sectional view along a plane perpendicular to the axis X, of a notch of the stator according to the prior art;

Figures 4, 5, 6 and 7 show a sectional view along a plane perpendicular to the axis X, of a notch of the stator receiving the branches of pins according to the prior art;

Figures 8, 9, 10 and 11 show a sectional view along a plane perpendicular to the axis X, of a notch of the stator according to a first embodiment of the invention; and Figure 12 shows a sectional view along a plane perpendicular to the axis X, of a notch of the stator according to a second embodiment of the invention.

Identical, similar, or analogous elements keep the same reference from one figure to another.

Throughout the description, the terms width used to qualify the notch and the branches of pins correspond to the dimension of the notch and the branches of pins in an ortho-radial direction, likewise the terms length used to qualify the notch and the branches of pins correspond to the dimension of the notch and the branches of pins in a radial direction.

DESCRIPTION OF EXAMPLES OF EMBODIMENT OF THE INVENTION

Figure 8 shows a sectional view along a plane perpendicular to the axis X of a notch 103 of the stator 50 of the electric machine 100 according to the invention. This stator can replace the stator of the state of the art in place of the stator 50 illustrated in FIG. 1.

This notch 103 differs in particular from that of FIG. 4 in that it is trapezoid in shape so that, as described below, the insertion clearance of the at least one high location 109 of the notch is greater than the set for insertion of the bottom location 108 of the notch.

A trapezoidal notch is understood to mean a notch, the two radial edges 105a and 105b of which converge towards the air gap 110.

Thus, for example, as can be seen in FIG. 9, the stator 50 comprises a tooth 106 defined between two adjacent notches 103. Each of the two notches 103 has a trapezoidal shape and includes edges 105a and 105b covered with an insulator 104. As can be seen for each of the notches 103, the two edges 105a and 105b converge towards the air gap 110.

Two edges 105b and 105a form the two sides of the tooth 106. As can be seen by straight lines 117 and 118 which extend the two sides of the tooth 106, the two sides diverge towards the air gap 110.

One could also provide that the two sides of the tooth 106 are parallel, one then obtains a tooth 106 with parallel sides. It should be noted that this would not prevent the edges of the notches 103 from converging, in fact, in general, the stator body is of annular and curved shape.

The different insertion sets of the notch 103 are illustrated in FIG. 8. These are the insertion sets 113, 114, 115, 116 measured between one of the pin arms 101b or 102a and the edges notch covered with insulation 104.

More precisely, the insertion clearances 113 and 114 of the low location 108 are measured between the pin branch 101b occupying the low location 108 and the edge 105a covered with the insulation 104, the insertion clearances 115 and 116 of the high location 109 are measured between the pin branch 102a occupying the high location 109 and the edge 105a covered with the insulation 104.

As can be seen in Figure 8, we obtain the relationship below:

116> 115> 114> 113, i.e. the insertion clearance 116 is greater than the insertion clearance 115 which is itself greater than the insertion clearance 114 which is itself greater than the insertion clearance 113 This is due in particular to the divergence of the edge 105a relative to the edge 105b when one moves away from the air gap 110 while the locations and the branches of pins which they receive are aligned.

In this way it is obtained in particular that the insertion clearance of the at least one top location 109 of the notch is greater than the insertion clearance of the bottom location 108 of the notch.

For example, it can be chosen that the insertion clearance of a low location 108 is less than 0.1 mm. I.e. 0.1mm> 113 and / or 0.1mm> 114.

As illustrated in FIG. 8, two slots 108 and 109 are provided in the notch 103 for receiving two pin branches. One could also provide four locations 108, 109, 109 and 109 as illustrated in FIG. 5 with trapezoid notch edges allowing an increase in insertion clearance when moving away from the air gap 110.

The pins branches 102a and 101b have for example parallel sides. More specifically, the pin branches have a section in a plane perpendicular to the axis X, the two sides of substantially radial orientation are parallel. We then speak of a branch of pins with parallel sides.

FIGS. 10 and 11 illustrate the positioning of the pin branches in the top 109 and bottom 108 locations of the notch 103 in the case of an offset and an inclination of the pin branches respectively, these offsets and inclinations being substantially equal to those illustrated in FIGS. 6 and 7. As can be seen in FIGS. 10 and 11, due in particular to the width of the notch at the top location 109, with the same inclinations and offsets, this is avoided collisions that cause problematic insertion. This is particularly advantageous since this is achieved without reducing the amount of flux drawn up by the tooth.

Indeed, for a given tooth if we consider its width with a substantially ortho-radial direction and its length with a radial direction, the amount of flow raised depends directly on the minimum width of the tooth over its entire length. Thus by appreciably increasing the width of the notch in the top location with the trapezoidal notch, a width of the narrow notch is preserved in the bottom location, which makes it possible not to decrease the minimum width of the tooth which is located at the notch opening according to the state of the art.

In addition, with a uniform insertion clearance, it was necessary to have an insertion clearance sufficiently large to allow a problematic insertion of the branches of pins in the high locations. Which, given the greater difficulties for the high location than for the low location, involved an unnecessarily large insertion clearance for the low location. On the contrary, by providing a non-uniform and especially greater insertion clearance for the high location, it is possible in return to provide for a less significant insertion clearance at the level of the low location and allowing an all the more significant increase in the lower part of the teeth.

FIG. 12 illustrates a notch 103 provided with the two pin branches according to a second embodiment in which it is provided that the pin branch 101b received in the bottom location 108 is stamped so that its section in a perpendicular plane at the X axis has a trapezoid shape corresponding to the trapezoid shape of the notch. The shape of the pin branch 101b received in the bottom location 108 is thus adapted to the trapezoid shape of the notch. The term “trapezoid pin branch” is understood to mean a pin branch, the two radial sides of which converge towards the air gap 110.

Claims (9)

1. Rotating electric machine (100) comprising: -a rotor (2) rotating around an axis (X) a stator (50) surrounding said rotor (2), the space between the rotor (2) and the stator (50) defining a gap (110) of the machine (100), the stator (50) comprising notches ( 103), each of the notches comprises locations (108, 109) for receiving pins, in which for each notch (103), said locations (108, 109) are aligned so that only one location called bottom location (108) is contiguous to the air gap and at least one other so-called top location (109) is not contiguous to the air gap, said top and bottom locations (108, 109) each receiving a pin branch with an insertion clearance, characterized in that the notch (103) is trapezoidal so that the insertion clearance (115, 116) of the at least one high location (109) of the notch is greater than the insertion clearance (113, 114) from the bottom location (108) of the notch. 2. Rotating electric machine according to the preceding claim characterized in that the stator (50) comprises teeth (106) defined between two adjacent notches (103), said teeth being with parallel sides. 3. Rotating electric machine according to claim 1 or 2, characterized in that the insertion clearance of a low location (108) is less than 0.1 mm. 4. Rotating electric machine according to one of the preceding claims, characterized in that the stator (50) comprises an insulator (104), said insulator (104) covering the edges of at least one notch (103). 5. Rotating electric machine according to the preceding claim, characterized in that the insulator (104) is an S-shaped insulator. 6. Rotating electric machine according to one of the preceding claims, characterized in that each notch (103) comprises four locations (108, 109) for receiving four pin branches (101a, 102b). 7. rotary electric machine according to one of the preceding claims, characterized in that for each notch (103), at least one branch 5 pin having a section (101a, 102b) in a plane perpendicular to the axis X, said section comprises sides oriented substantially radially which are parallel. 8. Rotating electric machine according to one of the preceding claims, characterized in that the pin branch (101a, 102b) received in a 10 bottom location (108) is stamped so that its section in a plane perpendicular to the axis X has a trapezoidal shape corresponding to the trapezoidal shape of the notch (103). 9. rotary electric machine according to one of the preceding claims, characterized in that for each pin (101, 102) having a branch 15 received in a low location (108) of a notch (103), its other branch is received in a high location (109) of another notch (103). 1/12