EP4754861A1

EP4754861A1 - Stator of a rotating electrical machine

Info

Publication number: EP4754861A1
Application number: EP24748974.3A
Authority: EP
Inventors: Carsten Siepker
Original assignee: Valeo eAutomotive Germany GmbH
Current assignee: Valeo Electrification SAS
Priority date: 2023-08-02
Filing date: 2024-08-02
Publication date: 2026-06-10
Also published as: CN121620852A; FR3151948A1; WO2025027189A1

Abstract

Title of the invention: Stator of a rotating electrical machine The present invention relates to a stator (4) of a rotating electrical machine (1) wherein at least one notch (22) comprises a reception zone (220) for conductive elements and a neck (221) extending the reception zone (220) towards the internal periphery (20) of the body (14) of the stator, the reception zone (220) having an abutment face (222) preventing the disengagement of the conductive elements in the direction of the internal periphery (20) which is orthoradial, the neck (221) having a width, measured in an orthoradial direction, which is variable over at least part of the distance between the abutment face (222) and the internal periphery (20).

Description

DESCRIPTION

Title: Stator of a rotating electrical machine

The present invention relates to the field of rotating electrical machines and more particularly to the field of wound stators present in such rotating electrical machines.

In general, a rotating electrical machine comprises a rotor movable in rotation and secured to a drive shaft and a fixed stator around which, or inside which, the rotor is capable of rotating.

The stator comprises a body and an electrical winding. The body of the stator forms a part of revolution consisting of a stack of thin sheets along an axis of revolution of the stator, the body being provided with a plurality of teeth forming two by two notches sized to receive conductive elements of the electrical winding. The inner radial end of each tooth forms a tooth root, each tooth root being able in particular to be configured to retain the conductive elements of the electrical winding inside their corresponding notch once in position.

In an electric motor, the circulation of a current in the electric winding of the stator participates in generating a rotating magnetic field effect circulating in the metal body of the stator, and the rotor, equipped with an magnetic element, such as for example a winding or permanent magnets, is capable of rotating inside the stator by electromagnetic drive. Reversibly, a mechanical rotational movement of the rotor equipped with a magnetic element can generate the creation, via an electromagnetic interaction with the wound stator, of an electric current in the conductive elements of the electrical winding.

The electrical winding is organized in phase windings which cross the stator axially in the notches and which form connections at the axial ends of the stator to form a continuity of the winding from one notch to another. These windings can in particular be polyphase windings connected in star or in triangle, the outputs of which are connected to an inverter which can function, if necessary, as a bridge rectifier. The electromagnetic performance of the rotating electrical machine depends on the one hand on the correct positioning of the magnetic components relative to each other and on the other hand on the amount of magnetic flux leakage.

Regarding the first point, the designers of a rotating electrical machine must therefore consider the position of the electrical winding of the stator with respect to the rotor, and in particular means are sought to ensure the radial position of the conductive elements forming the electrical winding, at a distance from an air gap formed between the stator and the rotor.

Concerning the second point, the designers of a rotating electrical machine must in particular limit the quantity of magnetic flux which does not circulate according to a theoretical flux loop passing from the rotor to the stator via an air gap at the level of a first tooth, going around of the notch wound within the stator body passing from this first tooth to the adjacent tooth via a core of the body arranged opposite the air gap with respect to the notch, and returning towards the rotor via an air gap at the level of this adjacent tooth.

The present invention falls within this context by proposing a stator of a rotating electrical machine, the configuration of the notches of which makes it possible both to ensure stable positioning of the conductive elements of the electrical winding within the notches and to generate a barrier to magnetic flux leakage which does not limit the magnetic flux circulation performance within the stator.

The main object of the present invention is thus a stator of a rotating electrical machine for a motor vehicle intended to surround a rotor of said rotating electrical machine, the stator extending along a longitudinal extension axis, said stator comprising a body and an electrical winding, said body having an internal periphery intended to face the rotor, said body comprising a plurality of teeth delimiting notches, said notches extending radially within the body of the stator, from one longitudinal axial end to the other of the body of the stator, the winding comprising conductive elements located in the notches, characterized in that at least one notch comprises a reception zone for the conductive elements and a neck extending the reception zone towards the internal periphery of the body of the stator, the reception zone having an abutment face preventing the disengagement of the conductive elements in the direction of the internal periphery, said abutment face being orthoradial, the neck having a width, measured in an orthoradial direction, which is variable over at least part of the distance between the abutment face and the internal periphery.

It should be noted that by variable width of the neck, it has to be understood a modification of the width other than those which could be generated by the manufacturing tolerances of the stator. This variable width can just as well be obtained by an average width of a part of the neck which is different from the average width of another part of the neck, as by an evolutionary width of one of the parts of the neck while approaching the rotor, and if necessary, by both. More particularly, the width of the neck is variable in that it decreases as one approaches the internal periphery of the stator body.

The stator according to the invention makes it possible in particular to optimize the circulation of the magnetic flux within the stator body and thus to improve the performance of the rotating electrical machine. The presence of a neck of variable width makes it possible on the one hand to form an effective barrier against the escape of magnetic flux from one tooth to another without the flux having gone around the notch or without it is passed from the stator to the rotor, and on the other hand to ensure a minimal width at the level of the internal periphery of the stator to optimize the quantity of magnetic flux which can pass from the rotor to the stator and vice versa. Such a variable-width neck can advantageously be combined with the presence of an abutment face delimiting the zone for receiving the conductive elements within the notch, which is orthoradial, to ensure the correct positioning of the electrical winding in the stator and to avoid movements which could damage an insulator interposed between the conductive elements and the walls delimiting the notch.

According to an optional feature of the invention, the width of the neck at the abutment face of the reception zone is greater than the width of the neck at the internal periphery of the stator. The fact that the width of the neck at the abutment face of the reception zone is big allow preventing the magnetic flux leakage between the teeth. Meaning that it prevents the magnetic flux to go directly to the other tooth without circulation around the slot. The fact that the width of the neck at the internal periphery of the stator is small allow increasing the exchange surface for the magnetic flux with the rotor. Thus, the electromagnetic performances of the stator are improved.

According to an optional feature of the invention, the width of the neck is variable in that it gradually decreases from the abutment face of the reception zone towards the internal periphery.

According to an optional feature of the invention, the gradual decreases of the width of the neck is linear.

According to an optional feature of the invention, the neck has a widening portion, the width of which is variable, and an opening portion, opening onto the internal periphery.

In other words, the notch opens onto the internal periphery of the stator, via a slot of which at least a part is of variable width, said slot forming the neck.

According to an optional feature of the invention, the opening portion of the neck has a constant width.

According to an optional feature of the invention, the height of the widening portion, in a radial direction, is greater than the height of the opening portion, in the radial direction. This allow having a good saturation of the opening portion to increase the flux barrier effect and thus improve the performance of the machine.

According to an optional feature of the invention, the neck has a widening portion, the width of which is variable, from the abutment face of the reception zone to a portion of the body of the stator interposed between the neck and the internal periphery.

In other words, the notch does not open onto the internal periphery. According to an optional feature of the invention, the widening portion is, in a plane orthogonal to the longitudinal axis of extension, trapezoidal.

According to an optional feature of the invention, the widening portion is, in a plane orthogonal to the longitudinal axis of extension, a portion of a circle.

According to an optional feature of the invention, the width of the neck of a notch, at the level of the abutment face, is less than the dimension corresponding, measured in the same orthoradial direction, of a conductive element present in said notch.

According to an optional feature of the invention, the width of the said neck, at the level of the abutment face, is a value of the order of 50% to 80% of the value of the dimension corresponding, measured in the same orthoradial direction, of said conductive element.

In other words, the notch opens onto the internal periphery of the stator, via a slot, at least part of which is of variable width.

The invention also relates to a rotating electrical machine comprising a rotor and a stator as previously mentioned, the internal periphery of the stator and an external periphery of the rotor being arranged so as to form between them an airgap.

According to an optional feature of the invention, the conductive elements consist of segments electrically connected to one another at the longitudinal axial ends of the stator.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows, and exemplary embodiments given by way of indication and not limitation with reference to the appended drawings, including:

[Fig 1] is a general perspective view of a rotating electrical machine according to the invention;

[Fig 2] is a perspective view of a stator of the rotating electrical machine of Figure 1 comprising at least one electrical winding; [Fig 3] is a top view of the stator of Figure 2, without the electrical winding, making more particularly visible a plurality of notches formed in a body of the stator and leading to an internal periphery of this body;

[Fig. 4] illustrates a detail of the stator of Figure 3, without the electrical winding, but this time with the rotor of the rotating electrical machine and the air gap arranged between rotor and stator, which makes more particularly visible a form of notch specific to the invention, according to a first embodiment;

[Fig. 5] illustrates the detail of the stator of Figure 4, with the notch according to the first embodiment, and conductive winding elements as well as an electrical insulator arranged between these conductive elements and the walls delimiting the notch;

[Fig. 6] is a view similar to that of Figure 5, with a notch according to a second embodiment;

[Fig. 7] is a view similar to that of Figure 5, with a notch according to a third embodiment;

[Fig. 8] is a simplified representation of Figure 6, without electrical insulation and cutting lines, on which are pointed dimensional characteristics specific to the invention;

[Fig. 9] is a simplified representation of Figure 6, without electrical insulation and cutting lines, on which are pointed other dimensional characteristics specific to the invention.

The features, variants and different embodiments of the invention may be associated with each other, in various combinations, insofar as they are not incompatible or exclusive with respect to each other. In particular, variants of the invention maybe imagined comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage and/ or to differentiate the invention, compared to the prior art.

In the figures, the elements common to several figures retain the same reference. As a reminder, the invention relates to a particular arrangement, within a stator of a rotating electrical machine, of a notch for receiving an electrical winding which makes it possible to optimize the electromagnetic performance of this rotating electrical machine.

The invention, which will be described in more detail below, is particularly applied in rotating electrical machines, such as that illustrated in the exploded view of Figure i, which can for example be used as an electrical motor for vehicle.

To this end, the rotating electrical machine 1 comprises, inside a casing 2 here formed of two shells able to be fitted against one another, a rotor/stator assembly. More particularly, the rotor/stator assembly, here with an internal rotor, comprises a stator 4, which is equipped with an electrical winding 6 capable of being connected by a connector 8 suitable for an electrical network, and a rotor 10 capable of rotating inside the stator and secured to a shaft 12 which extends along a longitudinal axis of extension X. The rotor 10 comprises magnetic elements, for example permanent magnets, capable of interacting with a rotating magnetic field created by the power supply of the electrical winding 6.

The stator 4, more particularly visible in Figures 2 and 3, comprises a body 14 formed by a stack of laminations stacked against each other along an axis of revolution R of the stator, parallel to the axis of longitudinal extension X of the previously mentioned rotating electrical machine. In the description, the terms radial and axial refer to the axis of revolution R of the stator 4 and/ or to the axis of longitudinal extension X, and the notions of interior and exterior also refer to these axes, an inner surface of a part of the rotating electrical machine being closer to the axis of revolution than an outer surface of this same part.

The body 14 of the stator 4 comprises at least a core 15 which extends around the axis of revolution R of the stator 4, and projecting from which is formed a plurality of teeth 16, visible in FIG. 3. Each tooth 16 extends radially towards the axis of revolution of the stator and the free end of each of the teeth, forming a tooth root 18 facing the inside of the stator, participates in delimiting an internal periphery 20 of the body 14 of the stator. The plurality of teeth 16 also makes it possible to delimit a plurality of notches 22 in pairs. More specifically, two adjacent teeth 16 delimit a notch 22 of the stator body, each of the notches being intended to receive conductive elements 24 of the electrical winding 6 of stator 4 as shown in Figure 2.

The notches 22, more particularly visible in Figures 4 and 5, each comprise two side walls 26 which extend radially and a bottom wall 28 which connects the two side walls 26 at the level of the core 15, that is to say that connects the outer radial ends of the two side walls. Opposite the bottom wall, on the side of the inner radial ends of the two side walls, each notch 22 opens onto a neck 221 which is particular according to the invention in that, opening or not onto the internal periphery 20 of the body of the stator, it has at least one portion whose width is variable, as will be described in more detail in Figures 4 to 9.

The conductive elements 24 pass axially through the stator and are arranged in radial alignment within the slot, the ends of these conductive elements being connected to the ends of conductive elements passing axially through the stator in another slot to form a continuous winding. These conductive elements are in particular rigid segments each forming a branch of a U- shaped pin, so that one end of each conductive element is linked to the other branch of the pin at a longitudinal axial end of the stator, the other end being welded to a conductive element of another pin at the other longitudinal axial end of the stator 4.

Such a configuration of the conductive elements makes it possible in particular to insert the conductive elements 24 axially within the notches 22, which makes it possible to provide an average width of the neck 221 which is less than the corresponding dimension of the conductive elements 24 in order to enclose them in the notch 22.

Such a rotating electrical machine 1 is assembled such that the internal periphery 20 of the stator 4 extends a short distance from an outer periphery 11 of the rotor 10, with an air gap 13 of radial dimension allowing rotation of the rotor within the stator but allowing the propagation of a magnetic field forming loops around the notches and passing from the stator to the rotor.

FIG. 4 partially illustrates a notch 22, in the vicinity of the internal periphery 20, so that the bottom wall is not visible in this figure. The notch 22 is here without electric winding 6, in order to make the different parts of the notch more particularly visible.

The notch 22 comprises a reception area 220, configured to receive conductive elements of the electrical winding and an insulator arranged between the walls of the notch and the conductive elements, and the neck 221 mentioned above, which extends the reception area 220 towards the internal periphery 20. In the example illustrated in Figure 4, the neck 221 leads to the internal periphery 20, but as will be illustrated in Figures 7 and 8, this neck 221 can be closed.

According to the invention, the neck 221 comprises at least one portion of variable width. In other words, at least a portion of said neck has one dimension, measured in a direction perpendicular to the radial direction along which the notch 22 extends, which varies along this radial direction. More particularly, the width is variable in that it decreases while approaching the internal periphery of the stator body.

In the example illustrated in Figure 4, the neck 221 comprises a first portion whose width is variable and a second portion whose width is constant, the first portion leading to the reception area and the second portion leading to the internal periphery. The first portion forms a widening portion 223 and the second portion forms an opening portion 224.

As can also be seen in FIG. 4, the stator of the invention is special in that, combined to the variable width of the neck, the reception area 220 has an abutment face 222 which extends substantially perpendicularly from the side walls 26 delimiting the reception area of the notch 22. This face abutment extends parallel to the bottom wall of the previously mentioned notch and has the function of preventing the disengagement of the conductive elements 24 of the electrical winding towards the inside of the stator body, in the direction of the rotor. The abutment face 222 is here orthoradial, perpendicular to the radial direction of extension of the notch, to form a planar bearing surface for the conductive elements. As can be seen in FIGS. 5 to 7, this abutment face 222 also forms a bearing surface for the electrical insulator 25, which aims to avoid short circuits between the body of the stator and the conductive elements of the electrical winding. This electrical insulator 25 may in particular be in the form of a sheet of insulating paper, for example based on polyester, to which a shape substantially complementary to that of the zone for receiving the notch is given.

The neck 221 emerges at the center of the abutment face 222, presenting a width less than that of the abutment face 222, so that two bearing portions 225 are formed on either side of the opening formed by the neck 221 in the orthoradial abutment face 222.

A function of the neck 221 is to prevent leakage of magnetic flux and to ensure that the magnetic flux makes a loop passing from the stator to the rotor and passing around the winding of the notch, by ensuring that the winding present in the notch cannot slide towards the rotor.

More particularly, the neck 221 forms a narrowing of the passage section of the notch, in the direction of the internal periphery 20 of the stator, to ensure that the conductive elements are well blocked in the notch 22. The orthoradial arrangement of the abutment face 222 makes it possible to ensure a surface perpendicular to the direction of disengagement of the conductive elements towards the interior of the stator, and this makes it possible in particular to prevent the interior conductive element 24 of the winding from slipping towards the interior of the stator along the abutment face by pinching the electrical insulation 25 and damaging it.

The neck 221 forms advantageously, between the orthoradial abutment face 222 and the internal periphery 20 of the rotor, a clearance of metallic material which prevents the magnetic flux from propagating from one tooth 16 to another, between the air gap 13 and the notch 22, this which represents a leak which it is desired to minimize in order to optimize the magnetic flux circulating around the electrical winding and passing through the rotor. The clearance of material thus forms a flux barrier. The fact of having a variable width makes it possible to combine the existence of a clearance of material sufficiently wide to be effective against a radial passage of magnetic flux directly from one tooth root 18 to the other between the notch 22 and the internal periphery 20, and a large surface of material at the internal periphery 20 that optimizes the amount of magnetic flux passing axially through the air gap 13 between rotor and stator.

In the stator according to the invention, the opening portion 224 of small width makes it possible to have this large surface of material at the level of the internal periphery 20 and the widening portion 223 whose width increases as the distance of the air gap 13 makes it possible to increase the effectiveness of the barrier against flow leakage from one tooth root 18 to the other.

Furthermore, the configuration of the neck 221 makes it possible to ensure a minimum distance between the inner conductive element 24 and the rotor. It is then considered the radial dimension of the neck 221 and in particular the sum of the radial dimensions of the widening portion 223 and of the opening portion 224 so that the inner conductive element can be pushed far enough from the internal periphery 20 of the stator.

Also, and in combination with the previous dimensional characteristics, the radial dimension of the opening portion 224 must have a minimum value, in particular for questions of industrial feasibility. The body 14 of the stator is obtained by stacking layers superimposed on each other along the longitudinal dimension, each layer being obtained by stamping. In this context, the opening portion 224 must have a minimum value for the tooth roots 18 formed by the presence of this opening portion 224 to be sufficiently strong.

FIG. 5 illustrates a first embodiment of the notch, with the neck 221 which has been illustrated in FIG.4. The electrical insulator 25 rests on the abutment face 222, being pressed against this abutment face by the conductive elements 24 and in particular by the inner conductive element 24, that is to say the conductive element closest to the internal periphery 20 of the body 14.

The radial dimension of the neck 221 as a whole, from the abutment face 222 to the internal periphery 20 of the stator, is of the order of 2 mm, in particular in order to ensure a minimum distance of the order of 3mm between the rotor and the inner conductive element 24 present in the notch 22.

The width of the neck 221 is variable in that it gradually decreases from the abutment face 222 of the reception zone 220, to form the widening portion 223. More particularly, in that embodiment illustrated in FIG.5, the width of the neck 221 decreases linearly, in a manner to form an inclined plane between the abutment face 222 and the opening portion 224 which extends the widening portion as far as the internal periphery 20. In a plane orthogonal to the longitudinal axis of extension X, it is that is to say, in a section plane as illustrated in FIG. 5, the widening portion 223 has a trapezoidal profile.

The opening portion 224 of the neck 221 has a width L224 which is here constant and less than the average width of the widening portion 223.

Byway of example, the opening portion 224 has a width L224 of the order of 0.5mm. It could, without departing from the context of the invention, have a minimum value of 0.4 mm and a maximum value of 1.5 mm. And the variable width L223 of the widening portion 223 is in this case such that it varies from the width of the opening portion, at the level of the junction with the latter, for example by 0.5 mm, to the maximum width that it takes at the abutment face 222, for example 2 mm.

As mentioned, the minimum value of the width of the opening portion 224 must be respected to avoid obtaining fragile tooth roots 18, while the maximum value of this width of the opening portion 224 must be not exceeded to ensure a sufficiently large surface of the internal periphery 20 for the passage of the magnetic flux between rotor and stator through the air gap 13- The maximum width of the widening portion 223 at the level of the abutment face 222, which can vary depending on the width of the corresponding notch 22, must be observed to ensure that a sufficient bearing portion 225 is retained for the support of the inner conductive element 24 on the abutment face 222 of the notch.

In a non-limiting manner of the invention, considering the neck 221 in the plane of Figure 5 perpendicular to the axis of revolution of the stator, the widening portion 223 can be delimited by inclined walls, with respect to the radial dimension of the notch 22, at an angle of the order of 30° to 50°.

In other words, in this first embodiment, the notch 22 opens onto the internal periphery 20 of the body 14, via a slot part of which, here the widening portion 223, is of variable width, this variability being formed by an inclined plane. Such an embodiment maybe preferred in particular for the ease of making the inclined plane.

A second embodiment is illustrated in Figure 6 and differs from what has been described previously in the shape of the widening portion. In particular, in the same plane orthogonal to the longitudinal extension axis X as previously, the widening portion 223 this time has the shape of a portion of a circle, the radius of which is of the order of 1 mm, the center of this circle portion which can in particular be positioned in the plane of the abutment face 222.

Such an embodiment may be preferred for its electromagnetic efficiency, due to the fact that at the junction between the widening portion 223 and the opening portion 224, the width L223 of the widening portion 223 increases more rapidly than in the embodiment of a widening portion formed by an inclined plane. The barrier performance against magnetic flux leakage is thus increased. Here again, a minimum value of the width of the opening potion 224 must be respected for questions of feasibility of the layers of the stator 4 without causing fragility of the teeth roots 18. A third embodiment is illustrated in FIG. 7 and differs from what has been described previously in that the neck 221 comprises only a widening portion 223 of variable width, said widening portion 223 not opening onto the internal periphery 20 of the body 14. In other words, a portion of the body 14 of the stator is interposed between the neck 221 and the internal periphery 20 of the stator body.

This simplifies the cutting by stamping of the layers of the stator 4 since no notch opens onto the internal periphery 20 of the body 14 and teeth roots are not thus formed facing the notches 22.

FIGS. 8 and 9 illustrate the dimensional characteristics of the body 14 according to the invention, and more particularly the dimensional characteristics of the neck 221, in relation to the dimensions of the electric winding 6 intended to be housed in the corresponding notch 22.

It should be noted that these dimensional characteristics are illustrated with reference to the second embodiment of the notch, with a neck 221 having a curved profile, but that unless otherwise stated, these characteristics can be applied to the other embodiments of the notch.

More particularly, FIG. 8 shows that the width of the neck 221 of a notch 22 is less than the corresponding dimension D, measured in the same orthoradial direction, of a conductive element 24 present in this notch 22. The largest value of the width of the neck 221, that is to say the width of the widening portion 223 at the level of the abutment face 222, is smaller than the width of a conductive element 24, so that the inner conductive element 24 can rest stably on the plane wall, orthoradial, forming the abutment face 222. It is thus ensured that the inner conductive element 24 can rest against at least one of the two bearing portions 225, with the insulation, here not shown, interposed between the inner conductive element 24 and the abutment face 222. By way of example, the maximum width of the neck 221, at the level of the abutment face 222, is a value of 50% to 80% of the value of the corresponding dimension, measured in the same orthoradial direction, of the inner conductive element 24. In this way, it is ensured that the orthoradial dimension Do of the bearing surface 225 between the inner conductive element 24 and the abutment face 22 is at least 20% of the width of the notch 22, distributed over one and/or the other of the two bearing portions 225.

FIG. 9 more particularly illustrates the width differential within the neck, between the widening portion 223 and the opening portion 224. The width of the neck 22ican thus be considered as variable for two reasons. On the one hand, the average width of the widening portion 223 is greater than the average width of the opening portion 224. On the other hand, at least the width L223 of the widening portion 223 is variable from one radial end of this portion to the other radial end. More particularly, the width L223 of the widening portion 223 increases as it moves away from the air gap 13, to accentuate the barrier made to the radial passage of magnetic flux by increasing the quantity of air that the magnetic flux must cross to pass directly from one tooth 16 to the other. In particular, the average width L223 of the widening portion 223, which can be defined as the average of the width of the widening portion at the level of the abutment surface 222 and the width of the widening portion at the level of the junction with the opening portion 224, is greater than the radial dimension Dr of the air gap 13.

FIG. 9 also illustrates the radial dimension of the neck 221, which is defined so that the conductive elements 24 can be pushed outwards at a minimum distance Dm from the rotor. The radial dimension of the neck 221 is then calculated so that the sum of the radial dimension Dr224 of the opening portion 224 and the radial dimension Dr223 of the widening portion 223, also taking into account the thickness of the insulation, is at least equal to this minimum distance Dm, ensuring that the radial dimension of the opening portion is sufficient to allow the stamping of the layers of the stator without damaging the teeth 16 of the stator.

As it appears from the present description, the invention achieves the aims it had set itself by proposing a stator and an associated rotating electrical machine which make it possible to obtain high electromagnetic performance, without having to fundamentally modify the structure of the stator. The modification made to the shape of the notches and to the slot provided between these notches and the internal periphery of the stator allows to provide stability to the conductive elements of the electrical winding, in particular by the presence of an orthoradial abutment face, and to ensure good transmission of the magnetic flux around the electric winding by limiting magnetic flux leakage, in particular by the variable shape of the slot.

The present invention cannot however be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

1. Stator (4) of a rotating electrical machine (1) for a motor vehicle intended to surround a rotor (10) of said rotating electrical machine, the stator (4) extending along a longitudinal extension axis (X), said stator (4) comprising a body (14) and an electrical winding (6), said body (14) having an internal periphery (20) intended to face the rotor (10), said body (14) comprising a plurality of stator teeth (16) delimiting notches (22) extending radially within the body (14) of the stator (4), from one longitudinal axial end to the other of the body of the stator, the winding (6) comprising elements conductors (24) housed in the notches (22), characterized in that at least one notch (22) comprises a reception zone (220) for the conductive elements (24) and a neck (221) extending the reception zone (220) towards the internal periphery (20) of the body ( 14) of the stator, the reception zone (220) having an abutment face (222) preventing the disengagement of the conductive elements (24) in the direction of the internal periphery (20) which is orthoradial, the neck (221) having a width , measured in an orthoradial direction , which is variable over at least part of the distance between the abutment face (222) and the internal periphery (20).

2. Stator according to Claim 1, characterized in that the width of the neck (221) at the abutment face (222) of the reception zone (220) is greater than the width of the neck (221) at the internal periphery (20) of the stator.

3. Stator according to Claim 1 or 2, characterized in that the width of the neck (221) is variable in that it gradually decreases from the abutment face (222) of the reception zone (220) in the direction of the internal periphery (20). 4- Stator according to Claim 3, characterized in that the gradual decreases of the width of the neck (221) is linear.

5. Stator according to any one of the previous claims, characterized in that the neck (221) has a widening portion (223), the width of which is variable, and an opening portion (224), opening onto the internal periphery (20).

6. Stator according to Claim 5, characterized in that the opening portion (224) of the neck (221) has a constant width.

7. Stator according to Claim 5 or 6, characterized in that the height of the widening portion (223), in a radial direction, is greater than the height of the opening portion (224), in the radial direction.

8. Stator according to any one of the claims 1 to 4, characterized in that the neck (221) has a widening portion (223), the width of which is variable, from the abutment face (222) of the reception zone (220) to a portion of the body (14) of the stator interposed between the neck (221) and the internal periphery (20).

9. Stator according to any one of Claims 5 to 8, characterized in that the widening portion (223) is, in a plane orthogonal to the axis of longitudinal extension (X), trapezoidal.

10. Stator according to any one of Claims 5 to 8, characterized in that the widening portion (223) is, in a plane orthogonal to the longitudinal axis of extension (X), a portion of a circle.

11. Stator according to one of the preceding claims, characterized in that the width of the neck (221) of a notch (22), at the level of the abutment face (222), is less than the corresponding dimension, measured in the same orthoradial direction, of a conductive element (24) present in said notch (22).

12. Stator according to the preceding claim, characterized in that the width of the said neck (221), at the level of the abutment face (222), is a value of the order of 50% to 80% of the value of the corresponding dimension, measured in the same orthoradial direction, of said conductive element (24).

13. Rotating electrical machine (1) comprising a rotor (10) and a stator (4) according to any one of the preceding claims, the internal periphery

(20) of the stator (4) and an outer periphery (11) of the rotor (10) being arranged so as to form between them an air gap (13).

14. Rotating electrical machine according to the preceding claim, characterized in that the conductive elements (24) consist of pins electrically connected to one another at the longitudinal axial ends of the stator (4).