WO2023203295A1

WO2023203295A1 - Rotating electric machine

Info

Publication number: WO2023203295A1
Application number: PCT/FR2023/050548
Authority: WO
Inventors: Cyril Moya; Valentin BLANC
Original assignee: Nidec Psa Emotors
Priority date: 2022-04-22
Filing date: 2023-04-17
Publication date: 2023-10-26
Also published as: FR3134930A1

Abstract

The invention relates to a rotating electric machine comprising: a casing, a stator (1) comprising a stator mass (2), the stator (1) being disposed in the casing, in particular by shrink-fitting, one or more resilient strips (4) mounted on one of the stator (1) or the casing on the surface thereof, so as to face the other of the stator (1) or the casing, an angular extent of at least one resilient strip (4) about a longitudinal axis of the machine being strictly less than 360°, and a length (L) of said at least one resilient strip (4) being strictly less than a length of the stator mass (2).

Description

Title: Rotating electric machine

The present invention claims priority from French application 2203746 filed on April 22, 2022, the content of which (text, drawings and claims) is herein incorporated by reference.

Technical area

The present invention relates to rotating electrical machines and more particularly to the stators of such machines, inserted in a casing of the machine. The invention is more particularly interested in blocking the rotation of the stator relative to the casing.

The invention relates more particularly to synchronous or asynchronous alternating current machines. It concerns in particular traction or propulsion machines for electric (Battery Electric Vehicle) and/or hybrid (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle) motor vehicles, such as individual cars, vans, trucks or buses. The invention also applies to rotating electrical machines for industrial and/or energy production applications, in particular naval, aeronautical or wind turbines.

Prior art

In order to lock the stator in rotation relative to a casing of the machine, it is known to use a tight fitting of the stator in the casing, produced by hot expanding the casing. However, when using the machine at high temperatures, the housing may expand again, and the stator may lose its tightness. Conversely, the cold can cause the material to contract and the casing can break. A stronger but more expensive alloy or a heat treatment to strengthen the casing material, also expensive, may be necessary to overcome these problems.

It is also known to use an anti-rotation stop, by key or by screwing or pin. However, this requires machining the stator as well as the housing, and the use of additional parts. Furthermore, in the case of a stop by screwing or pin, drilling the stator and the casing can release polluting machining chips, and the manufacturing process can be disrupted by the machining cycle. Furthermore, in the case of a key stop, the use of a key requires precise positioning of the stator relative to the casing, which even when well done, does not prevent residual play.

The use of a tolerance ring can also be effective in blocking the stator from rotating, but this can cause strong stress on the casing which risks cracking.

Document EP 3 493 369 relates to a stator comprising plastic strips extending over the entire length of the stator, distributed angularly around the longitudinal axis of the stator. These plastic strips include bosses of partially circular shape, arranged over the entire length of the strips, the axis of curvature of which extends perpendicular to a longitudinal axis of the stator. This document also describes elastic elements formed in one piece with the stator sheets.

Document EP 3 836 368 describes an elastic ring made of organic material, in particular plastic, mounted around a stator, and comprising bosses. This elastic ring does not provide a sufficiently high support force to ensure that the stator is held in a casing during shrinking.

In document US 2010/320865, springs extend over the entire length of the stator, being clipped at each end. They are distributed angularly around the longitudinal axis of the stator and each comprise a single longitudinal boss, with an axis of curvature of the boss which extends parallel to the longitudinal axis of the stator.

In document US 2020/235617, there are inserts, spaced angularly around the longitudinal axis of the stator, each insert comprising a first part inserted in a suitable housing on the external surface of the stator, and a second part inserted in a housing adapted to the internal surface of the casing. Such a configuration requires machining of the stator and the casing, as well as very precise positioning between them.

In document DE 10 2006 036836, springs in the form of split tubes are used, distributed angularly around the longitudinal axis of the stator, arranged between the stator and the casing. These spring elements extend over the entire length of the stator and are inserted into suitable housings on the external surface of the stator, from which they project. There may not be sufficient heat transfer between the stator and the casing, with a layer of air existing between the two. Document US 2015/0022052 describes a cylinder fitted onto the external surface of the stator, between the stator and the casing. This cylinder extends the entire length and circumference of the stator. In addition, it is fixed on either side of the stator.

Document US 2020/0144882 relates to a corrugated spring disposed between the stator and the casing, extending over the entire circumference of the stator, the spring being compressed when inserting the stator into the casing.

In document US 2020/112226, the stator sheets have cutouts on the external surface of the stator, integral with the sheets, which are in contact with the internal surface of the casing when the stator is inserted into the casing.

Documents US 2020/0313500 and US 2016/0156245 relate to stators attached to the casing by tie rods or by nuts and bolts.

There is therefore a need to facilitate the rotational locking of the stator in the casing, and to reduce the cost.

Summary of the invention

The invention aims to meet this need and it achieves this, according to one of its aspects, thanks to a rotating electric machine comprising:

- a casing,

- a stator comprising a stator mass, the stator being arranged in the casing, in particular by hooping,

- one or more elastic strips attached to one of the stator or the casing on its surface facing the other of the stator or the casing, an angular extent of at least one elastic strip around a longitudinal axis of the machine being strictly less than 360°, a length of said at least one elastic strip being strictly less than a length of the stator mass.

By “slat”, we must understand a piece of relatively small thickness in relation to its length and width.

By “elastic lamella”, it should be understood that the elastic lamella has the property of regaining, at least partially, its shape and/or its volume, after deformation. The elastic lamella(s) may lose their shape and/or volume when of the insertion of the stator into the casing, for example by shrinking, in particular during expansion of the casing.

By “adjusted lamella”, it must be understood that the added lamella is a part manufactured independently of the stator and the casing.

The attached elastic strip(s), carried by one or the other of the stator or the casing, on its surface in contact with the other of the stator or the casing, makes it possible to provide a constant force between the stator and the casing of the made of their mechanical deformation, thus allowing anti-rotation reinforcement of the stator relative to the casing and therefore improving the performance of the hooping of the casing and the stator. In particular, if the casing expands, the elastic strip(s) make it possible to maintain this constant force on one or the other of the casing or the stator which does not carry them.

The elasticity of the lamellae allows the reversible assembly of the stator in the casing, said elastic lamellae being able to return to their initial shape and/or volume after removal of the stator.

The stiffening of the machine, and in particular of the assembly formed by the casing, the elastic strip(s) and the stator, makes it possible to reduce the vibration amplitudes and therefore the forces exerted on the most fragile elements. This makes it possible to minimize the various vibration risks. The stiffening of the machine also helps minimize noise due to vibrations.

The electric machine, however, retains enough flexibility so that the whole thing is not brittle.

When inserting the stator into the casing, the elastic strip(s) make it possible to reduce, or even eliminate, the waiting time necessary for the stator to be held by the casing.

The use of this or these elastic strips also makes it possible to avoid imposing strong alignment constraints on the stator in the casing and to reduce the forces of the stator on the casing. This makes it possible to avoid machining the stator if the blades are attached to the casing. This also makes it possible to avoid machining the casing if the blades are attached to the stator. Thanks to the invention, it is also possible to avoid using a more resistant alloy for the casing. Finally, this makes it possible to avoid special heat treatment of the casing. In a variant embodiment, the casing can be manufactured by additive manufacturing. The machine can include between one and fifty elastic strips, preferably between two and thirty elastic strips, or even for example between three and twenty elastic strips.

At least one elastic blade, preferably at least two elastic blades, better still all the elastic blades can be carried by the stator. Alternatively, at least one elastic strip, preferably at least two elastic strips, better still all the elastic strips can be carried by the casing.

That of the casing or stator which does not carry the elastic strip(s) may have a smooth surface facing this elastic strip(s).

By “angular extent of an elastic lamella”, we must understand the angle measured around a longitudinal axis of the machine, over which the elastic lamella extends, in its width.

By “width of an elastic strip”, we must understand the dimension of the side of the elastic strip measured in a plane normal to the longitudinal axis of the machine.

By “length of an elastic strip”, we must understand the dimension of the side of the elastic strip measured along the longitudinal axis of the machine.

By “length of the stator mass”, we must understand the dimension of the stator mass measured along the longitudinal axis of the machine.

By “casing” we must understand an envelope protecting the various internal elements of the electrical machine, in particular the stator. The casing may be rigid. This rigidity ensures that additional harmonics are not generated during vibration tests. The casing can be passive, that is to say devoid of electronic elements, in particular power electronics. The casing can be in one or more parts, in particular in one, two or three parts. The different parts of the casing can be joined together. Alternatively, the casing can be made in a single piece. The casing can be an integral part of the chassis of the device, for example of a vehicle, comprising the electrical machine. The casing can carry the main elements of the machine, in particular the stator.

The casing can be machined and/or can be made in a foundry and/or can be made using 3D printing. The casing can be made of metal, for example aluminum. Alternatively, the casing can be made of a plastic material.

The casing can be the main part of the machine in terms of weight and/or volume. By “shrinking” we must understand a tight fit between two parts, an outer one, for example the casing, and an inner one, for example the stator. The outer piece can be heated to expand it before putting it on the inner piece. Alternatively, the inner piece may be cooled to contract it before inserting it into the outer piece. You can also simultaneously heat the exterior room and cool the interior room.

Presentation of the invention

Elastic slats

At least one elastic strip may include at least one boss.

By “boss”, we must understand a part of the slat which projects. This means that at least one elastic strip has at least one projection.

At least one elastic strip can have between 1 and 82 bosses, preferably between 1 and 40 bosses, better still between 2 and 15 bosses, for example 1, 2 or 3 bosses.

Two, three, or even all of the elastic strips can have between 1 and 82 bosses, preferably between 1 and 40 bosses, better still between 2 and 15 bosses, for example 1, 2 or 3 bosses.

The shape of the boss(es) may depend on the material of the elastic strip(s) from which the boss(es) protrude and/or on their thickness.

At least one boss can be hollow, so that the thickness of the elastic strip from which the boss projects can be the same at the level of the boss as at the level of the flat part of the elastic strip.

Two, three, or even all of the bosses can be hollow.

At least one boss, better two, three, or even all the bosses can be closed at their ends. Alternatively, at least one boss, better still two, three, or even all the bosses can be open at their ends.

By “thickness of an elastic lamella”, we must understand the thickness of the material composing the elastic lamella, measured in a direction perpendicular to the plane in which the length and width of the lamella are measured. The thickness of at least one elastic strip can be between 0.1 mm and 2 mm, preferably between 0.2 mm and 1.5 mm, better still between 0.3 mm and 1 mm, better still between 0.4 mm and 0.7 mm, being for example equal to 0.5 mm.

The thickness of two, three, or even all of the elastic lamellae can be between 0.1 and 2 mm, preferably between 0.2 mm and 1.5 mm, better between 0.3 mm and 1 mm, better between 0.4 mm and 0.7 mm, being for example equal to 0.5 mm.

By “height of a boss”, we must understand the distance between the surface of the elastic strip from which the boss projects and the upper surface of the boss.

The height of at least one boss before insertion of the stator into the casing may be between 0.1 mm and 5 mm, preferably between 0.3 mm and 4 mm, better still between 0.5 mm and 3 mm, better still between 0.7 mm and 2 mm, being for example equal to 1.4 mm.

The height of at least one boss after insertion of the stator into the casing can be between 0 mm and 5 mm, preferably between 0.3 mm and 4 mm, better still between 0.5 mm and 3 mm, better still between 0. 6 mm and 1.8 mm, being for example equal to 1.2 mm.

The height of two, three, or even all of the bosses, before insertion of the stator into the casing can be between 0.1 mm and 5 mm, preferably between 0.3 mm and 4 mm, better still between 0.5 mm and 3 mm, better between 0.7 mm and 2 mm, being for example equal to 1.4 mm.

The height of two, three, or even all of the bosses, after insertion of the stator into the casing can be between 0 mm and 5 mm, preferably between 0.3 mm and 4 mm, better still between 0.5 mm and 3 mm , better between 0.6 mm and 1.8 mm, being for example equal to 1.2 mm.

By “height of an elastic lamella”, we must understand the distance between the lowest surface and the most upper surface of the elastic lamella, measured in a direction perpendicular to the plane in which the length and width of the lamella are measured. slat.

The height of at least one elastic strip before insertion of the stator into the casing can be between 0.5 mm and 20 mm, preferably between 0.5 mm and 8 mm, better still between 0.5 mm and 2 mm, being for example equal to 1.9 mm.

The height of at least one elastic strip after insertion of the stator into the casing can be between 0.2 mm and 19.7 mm, preferably between 0.2 mm and 7.7 mm, better still between 0.2 mm and 1.7 mm, being for example equal to 1.7 mm. The height of two, three, or even all of the elastic lamellae before insertion of the stator into the casing can be between 0.5 mm and 20 mm, preferably between 0.5 mm and 8 mm, better still between 0.5 mm and 2 mm, being for example equal to 1.9 mm.

The height of two, three, or even all of the elastic lamellae after insertion of the stator into the casing can be between 0.2 mm and 19.7 mm, preferably between 0.2 mm and 7.7 mm, better still between 0 .2 mm and 1.7 mm, being for example equal to 1.7 mm.

At least one boss may have a rounded top. Alternatively, at least one boss may have a flattened top. Two, three, or even all of the bosses can have a rounded top. Alternatively, two, three, or even all of the bosses may have a flattened top. The rounded boss allows the material to be locally deformed, which allows the material to grip better. Thus, the coefficient of friction is increased and therefore improved.

At least one boss may be circular, rectangular, or square in shape. Two, three, or even all of the bosses can be circular, rectangular, or square.

By “length of a boss”, we must understand the dimension of the corresponding projection extending along the axis of the boss.

The length of at least one boss can be between 1 mm and 190 mm, preferably between 1 mm and 110 mm, better still between 1 mm and 60 mm, better still between 1 mm and 30 mm, better still between 1 mm and 15 mm. mm, being for example equal to 15 mm.

The length of two, three, or even all of the bosses can be between 1 mm and 190 mm, preferably between 1 mm and 110 mm, better still between 1 mm and 60 mm, better still between 1 mm and 30 mm, better still between 1 mm and 15 mm, being for example equal to 15 mm.

By “width of a boss”, we must understand the dimension of the corresponding projection extending perpendicular to the axis of the boss.

The width of at least one boss can be between 1 mm and 40 mm, preferably between 1 mm and 15 mm, better still between 1 mm and 5 mm, being for example equal to 5 mm.

The width of two, three, or even all of the bosses, can be between 1 mm and 40 mm, preferably between 1 mm and 15 mm, better still between 1 mm and 5 mm, being for example equal to 5 mm. Two, three, or even all the elastic strips of the same machine can have at least one boss of identical shape and dimensions.

Two, three, or even all the elastic strips of the same machine can have two, three, or even all of their bosses of identical shape and dimensions.

At least one elastic strip may comprise a single boss which can be flattened on the top, or rounded on the top, being for example of substantially circular shape. This single boss can be centered on said at least one slat.

An elastic strip comprising a single boss may have a narrower width than an elastic strip comprising several bosses. This ensures better continuity of heat transfer between the casing and the stator. The positioning of the elastic slats having a single boss is easier than the positioning of the elastic slats having several bosses, which are wider. Using elastic slats with a single boss also makes it possible to reduce the cost compared to using slats with several bosses.

Alternatively, at least one lamella may include three bosses extending preferably along parallel axes, rounded on top, being for example of substantially circular shape. The axes along which the three bosses extend can be separated by a distance of between 1 mm and 20 mm, preferably between 3 mm and 15 mm, better still between 5 mm and 10 mm, being for example equal to 8 mm. . This distance can be the same between the first side boss and the central boss, and the second side boss and the central boss. The distance between bosses is measured at the top of each boss.

An elastic slat comprising three bosses allows better distribution of forces compared to an elastic slat comprising a single boss.

At least one elastic strip can be positioned so that at least one boss extends along an axis parallel to the longitudinal axis of the machine.

The orientation of said at least one boss parallel to the longitudinal axis of the machine allows better angular blocking than the orientation of said at least one boss perpendicular to the longitudinal axis of the machine.

Alternatively, at least one elastic strip can be positioned so that at least one boss extends in a plane perpendicular to the longitudinal axis of the machine, or at least one elastic strip can be positioned so that at least one boss extends diagonally from said at least one elastic strip.

Two, three, or even all of the elastic strips of the machine can have at least one boss extending in the same direction, in particular along axes parallel to the longitudinal axis of the machine.

Two, three, or even all of the elastic strips of the machine can have two, three, or even all of their bosses extending in the same direction, in particular along axes parallel to the longitudinal axis of the machine.

It is also possible to have on the same machine, at least one elastic strip with at least one boss extending in one direction and at least one elastic strip with at least one boss extending in another direction.

The length of at least one elastic strip can be between 3 mm and 200 mm, preferably between 3 mm and 110 mm, better still between 3 mm and 70 mm, better still between 3 mm and 40 mm, being for example equal to 18 mm or 36 mm.

Two, three, or even all of the elastic strips of the machine can have a length of between 3 mm and 200 mm, preferably between 3 mm and 110 mm, better still between 3 mm and 70 mm, better still between 3 mm and 40 mm, being for example equal to 18 mm or 36 mm.

Two, three, or even all of the elastic slats of the machine can be of the same length.

Having elastic lamellae of length less than that of the stator mass allows for better heat transfer between the stator and the casing.

The angular extent of at least one elastic strip may be less than or equal to 350°, preferably less than or equal to 300°, better still less than or equal to 250°, even better less than or equal to 200°, even better less than or equal to 250°. equal to 150°, even better less than or equal to 100°, being for example less than or equal to 50°, for example equal to 13°.

Two, three, or even all of the elastic blades of the machine can have an angular extent less than or equal to 350°, preferably less than or equal to 300°, better still less than or equal to 250°, even better less than or equal to 200° , even better less than or equal to 150°, even better less than or equal to 100°, being for example less than or equal to 13°. Having elastic lamellae of small angular extent makes it possible to obtain better heat transfer between the stator and the casing.

The angular extent of at least one elastic strip may be greater than or equal to 1°, preferably greater than or equal to 5°, better still greater than or equal to 9°, being for example greater than or equal to 13°.

Two, three, or even all the elastic blades of the machine can have an angular extent greater than or equal to 1°, preferably greater than or equal to 5°, better still greater than or equal to 9°, being for example greater than or equal to 13 °.

The width of at least one elastic strip can be between 5 mm and 1600 mm, preferably between 5 mm and 1000 mm, better between 5 mm and 600 mm, better between 5 mm and 300 mm, better between 5 mm and 100 mm, better still between 5 mm and 30 mm, being for example equal to 24 mm.

Two, three, or even all of the elastic slats of the machine can have a width of between 5 mm and 1600 mm, preferably between 5 mm and 1000 mm, better between 5 mm and 600 mm, better still between 5 mm and 300 mm, better between 5 mm and 100 mm, better still between 5 mm and 30 mm, being for example equal to 24 mm.

Two, three, or even all the elastic slats of the machine can be of the same angular extent, and/or of the same width.

Beyond a certain angular extent of the elastic lamella, it can have a rounded shape adapted to the shape of the external surface of the stator.

Two, three, or even all of the elastic slats of the machine can be made of the same material.

At least one elastic strip may be at least partially made of a metallic material, preferably at least partially made of steel or stainless steel or aluminum, better still at least partially made of aluminum-coated steel.

Two, three, or even all of the strips can be at least partially made of a metallic material, preferably at least partially made of steel or stainless steel or aluminum, better still at least partially made of steel coated with aluminum.

This allows continuity of local heat transfer from the casing to the stator and sufficient elasticity of the lamella, without deteriorating the thermal performance of the machine. At least one elastic strip, better two, even better all the elastic strips, can be made from a non-magnetic steel which can in particular be coated with aluminum or another metal.

At least one lamella can be made entirely of metal. Two, three, or even all of the slats can be made entirely of metal.

Due to their metallic construction, the elastic lamellae, in particular three lamellae aligned circumferentially and spaced 120° apart, are capable of providing a high support force, in particular of the order of 120 Nm to 400 Nm.

Stator mass

The stator mass may have a diameter less than or equal to 1000 mm, preferably less than or equal to 500 mm, better still less than or equal to 300 mm, in particular equal to 210 mm.

The stator mass can have a length of between 10 mm and 1500 mm, preferably between 40 mm and 1000 mm, better still between 60 mm and 500 mm, better still between 80 mm and 200 mm, for example equal to 90 mm, equal to 110 mm, or even equal to 175 mm.

In a variant embodiment, the stator mass may comprise a ferrous composite.

The stator mass can be formed from a stack of sheets. The stack of sheets can include between 2 and 5600 sheets, preferably between 50 and 1000 sheets, better still between 200 and 850 sheets, for example 407 sheets.

At least one sheet may have a thickness of between 0.1 mm and 1 mm, preferably between 0.2 mm and 0.8 mm, better still between 0.2 mm and 0.4 mm, for example equal to 0, 27mm.

The stator mass can be composed of at least one pack of sheets, preferably of at least two packs of sheets, the packs of sheets being arranged consecutively along the longitudinal axis of the machine.

The stator mass can comprise between 1 and 1000 packs of sheets, preferably between 2 and 500 packs of sheets, better still between 3 and 8 packs of sheets, better still between 3 and 6 packs of sheets.

At least one pack of sheets can contain between 2 and 1000 sheets, preferably between 10 and 800 sheets, better between 20 and 600 sheets, better still between 30 and 400 sheets, better still between 40 and 200 sheets, for example 68 sheets. In one embodiment, the stator mass can comprise three packs of sheets. In another embodiment, the stator mass can comprise six packs of sheets. Alternatively, the stator mass may comprise a single pack of sheets.

At least two packs of sheets can each have the same length, or alternatively different lengths. All the packs of sheets can each have the same length, or alternatively different lengths. By “length of a pack of sheets”, we must understand the dimension of the pack of sheets extending along the longitudinal axis of the machine.

The arrangement of the packs of sheets in the stator mass can be such that the length of the packs of sheets can increase then decrease when moving along the longitudinal axis of the machine, or increase all along the stator mass , or decrease all along the stator mass.

As a further variation, the length of the packets can vary with a sawtooth variation when moving along the axis of the stator.

Sheets of sheet packs can be angularly offset around the longitudinal axis of the machine.

Sheets of the stator mass packages can be angularly offset all in the same direction around the longitudinal axis of the machine.

Alternatively, sheets of the packs of sheets of the stator mass can be angularly offset in at least two directions around the longitudinal axis of the machine.

Sheets of the sheet packs of the stator mass can be angularly shifted successively in one direction then in the other.

The angular offset of the packs of sheets of the stator mass makes it possible to distribute the geometry defects of the sheets over the entire circumference of the stator mass.

Sheets of the sheet packs of the stator mass may have different profiles from one sheet pack to another of the machine, in particular the external diameter of the sheets of the sheet packs may be different from one sheet pack to another .

For example, for a stator mass comprising at least two packs of sheets, for example six packs of sheets or three packs of sheets, the two lateral packs of sheets can have identical sheet profiles. Alternatively, the two side sheet packs may have different sheet profiles. In an embodiment comprising at least two packs of sheets, for example three packs of sheets or six packs of sheets, the sheet profiles of two consecutive packs of sheets may be identical or different.

In another embodiment comprising at least two packs of sheets, for example three packs of sheets or six packs of sheets, the packs of sheets can have identical sheet profiles every other pack or every third pack.

Positioning of the elastic slats

At least one elastic strip can be in contact with at least one sheet of the stack of stator sheets. At least one elastic strip can be in contact with between 1 and 5600 sheets, preferably between 3 and 1000 sheets, better between 50 and 500 sheets, better between 70 and 300 sheets, better between 100 and 200 sheets, for example an elastic strip can be in contact with 140 sheets.

At least one elastic lamella can be in contact with at least one pack of sheets of the stator mass. At least one elastic strip can be in contact with a single pack of sheets. Alternatively, at least one elastic strip can be in contact with strictly two consecutive packs of sheets of the stator mass.

At least one elastic strip can be of length substantially equal to the length of at least one pack of sheets of the stator mass. Alternatively, at least one elastic strip can be of length substantially equal to the sum of the lengths of two consecutive packs of sheets of the stator mass.

At least one elastic strip may not be in contact with at least one end sheet of the stack of sheets. At least one elastic lamella may not be in contact with at least one pack of end plates of the stator mass.

At least one pack of sheets can be in contact with between 1 and 500 elastic strips, preferably between 2 and 100 elastic strips, better still between 3 and 6 elastic strips. For example, at least one pack of sheets can be in contact with three elastic strips or six elastic strips.

In one embodiment, the stator mass can comprise three packs of sheets, with three elastic strips or six elastic strips in contact only with the central pack of sheets. Alternatively, the stator mass may comprise three packs of sheets, each in contact with only three elastic strips or six elastic strips. In one embodiment, the stator mass can comprise six packs of sheets, each in contact with only three elastic strips or six elastic strips. Alternatively, the stator mass can comprise six packs of sheets, each of the four central packs of sheets being in contact with only three elastic strips or six elastic strips.

In another variant, the stator mass can comprise six packs of sheets, the end packs not being in contact with elastic strips, three first elastic strips or six first elastic strips being in contact with strictly two first packs of sheets , and three second elastic strips or six second elastic strips being in contact with strictly two second packs of sheets.

At least two elastic lamellae can be aligned longitudinally along the longitudinal axis of the machine.

By “elastic slats aligned longitudinally”, it should be understood that these elastic slats are aligned along the same axis parallel to the longitudinal axis of the machine.

At least two elastic strips can be aligned longitudinally along the longitudinal axis of the machine, the first elastic strip being in contact with a first pack of sheets and the second elastic strip being in contact with a second pack of sheets.

The cumulative length of all the elastic lamellae aligned longitudinally can be strictly less than the length of the stator mass.

By “cumulative length of elastic slats aligned longitudinally”, we must understand the sum of the individual lengths of the elastic slats aligned longitudinally with each other along the same axis parallel to the longitudinal axis of the machine.

The distance between two longitudinally aligned elastic strips can be between 0 mm and 1500 mm, preferably between 5 mm and 1000 mm, better between 10 mm and 500 mm, better between 10 mm and 100 mm, better between 15 mm and 50 mm. , for example equal to 18.3 mm or 36.6 mm.

Elastic strips aligned longitudinally can be equally distributed along the longitudinal axis of the machine. This makes it possible to distribute the forces longitudinally between the stator and the casing. Alternatively, the distance between longitudinally aligned elastic lamellae may be irregular.

At least two elastic slats can be aligned circumferentially around the longitudinal axis of the machine, preferably three elastic slats can be aligned circumferentially or six elastic slats can be aligned circumferentially, around the longitudinal axis of the machine.

By “circumferentially aligned elastic slats”, we must understand elastic slats belonging to the same plane normal to the longitudinal axis of the machine.

At least two elastic strips can be aligned circumferentially around the longitudinal axis of the machine, the first elastic strip and the second elastic strip being in contact with the same pack of sheets.

The cumulative angular extent of all circumferentially aligned elastic lamellae may be strictly less than 360°, preferably less than or equal to 350°, preferably less than or equal to 300°, better still less than or equal to 250°, even better less than or equal to at 200°, even better less than or equal to 150°, even better less than or equal to 100°, for example equal to 39°.

By “cumulative angular extent of circumferentially aligned elastic lamellae”, we must understand the sum of the individual angular extents of the circumferentially aligned elastic lamellae.

The angular distance between two circumferentially aligned elastic strips can be between 1° and 180°, preferably between 30° and 150°, better still between 70° and 130°, for example 60° or 120°.

Circumferentially aligned elastic strips can be angularly evenly distributed around the longitudinal axis of the machine. This makes it possible to distribute the forces angularly between the stator and the casing.

In an embodiment comprising three elastic slats aligned circumferentially and angularly evenly distributed around the longitudinal axis of the machine, the angular distance between two elastic slats can be 120°.

Three elastic strips aligned circumferentially and angularly evenly distributed around the longitudinal axis of the machine allows a good compromise between a return of sufficient forces to the center of the stator, which could be less good with one or two circumferentially aligned elastic lamellae, and good heat transfer between the stator and the casing, which could be less good with more than three circumferentially aligned elastic lamellae.

In a variant embodiment comprising six elastic strips aligned circumferentially and angularly evenly distributed around the longitudinal axis of the machine, the angular distance between two elastic strips can be 60°.

Alternatively, the angular spacing between circumferentially aligned elastic lamellae may be irregular.

At least two elastic strips not aligned circumferentially can be offset angularly relative to each other around the longitudinal axis of the machine, in particular by an angle between 0° and 180°, preferably between 0° and 90°, being for example equal to 60°.

At least one sheet of the stack of sheets of the stator mass being in contact with a first elastic strip, at least one second sheet, in particular consecutive to the first sheet, being in contact with a second elastic strip, the first elastic strip and the second elastic strip can be angularly offset relative to each other around the longitudinal axis of the machine, for example by an angle between 0° and 180°, preferably between 0° and 90°, being for example of an angle equal to 60° or 30°.

In particular, a first elastic strip in contact with a first pack of sheets and a second elastic strip in contact with a second pack of sheets, in particular consecutive to the first, can be angularly offset one from the other around the the longitudinal axis of the machine, for example at an angle between 0° and 180°, preferably between 0° and 90°, being for example at an angle equal to 60° or 30°.

The distribution of the slats in an angular offset from one pack of sheets to another makes it possible to limit the stresses on the casing.

Fixing elastic slats

At least one elastic strip can be fixed on the stator or on the casing by snapping into a housing. Fixing by snap-fastening does not require any special machining of the stator or casing which does not carry the elastic lamella(s).

Two, three, or even all of the elastic blades can be fixed on the stator or the casing by snapping into housings. At least one housing suitable for snap-fastening may be of rounded shape, on an arc of a circle with a diameter of curvature substantially equal to the diameter of the stator mass.

At least one housing suitable for snap-fastening may have a bottom extending circumferentially on the stator or the casing, around the longitudinal axis of the machine.

At least one housing suitable for snap-fastening can be of length between 3 mm and 200 mm, preferably between 3 mm and 110 mm, better between 3 mm and 70 mm, better between 3 mm and 40 mm, for example equal at 18.3mm or 36.6mm. By “length of a housing”, we must understand the dimension of the side of the housing, measured along the longitudinal axis of the machine.

At least one housing suitable for snap-fastening can be of width between 5 mm and 1600 mm, preferably between 5 mm and 1000 mm, better between 5 mm and 600 mm, better between 5 mm and 300 mm, better between 5 mm and 100 mm, better between 5 and 30 mm, for example equal to 24 mm. By “width of a housing”, we must understand the dimension of the side of the housing, measured in a plane normal to the longitudinal axis of the machine.

At least one housing suitable for snap-fastening may have an angular extent of between 1° and 350°, preferably between 3° and 200°, better still between 5° and 100°, better between 7° and 60°, better between 10° and 20°, for example equal to 13°. By “angular extent of a housing”, we must understand the angle measured around the longitudinal axis of the machine, over which the width of the housing extends.

At least one housing suitable for snap-fastening may have a depth of between 0.1 mm and 10 mm, preferably between 0.5 mm and 5 mm, better still between 1 mm and 3 mm, for example equal to 1.7 mm. By “depth of a housing”, we must understand the radial dimension of the housing in relation to the longitudinal axis of the machine. At least one housing suitable for snap-fastening can be of constant depth over its entire length and width.

At least one housing suitable for snap-fastening can be of variable width depending on its depth. At least one housing suitable for snap-fastening may include at least one groove, preferably two grooves. The grooves can be arranged on the sides of the housing. At least one housing suitable for snap-fastening may comprise a first groove and a second groove opposite the first.

The first groove can extend along a first axis parallel to the longitudinal axis of the machine and the second groove can extend along a second axis parallel to the first axis.

At least one groove may be of length identical to the length of the housing suitable for snap-fastening. Preferably the first groove and the second groove can be of lengths identical to the length of the housing suitable for snap-fastening.

By “length of a groove”, we must understand the dimension of the groove measured along the longitudinal axis of the machine.

At least one groove may have a depth of between 0.03 mm and 25 mm, preferably between 0.1 mm and 10 mm, better still between 0.3 mm and 2 mm, better still between 0.5 mm and 1 mm, being for example equal to 0.65 mm.

The first groove and the second groove may have a depth of between 0.03 mm and 25 mm, preferably between 0.1 mm and 10 mm, better still between 0.3 mm and 2 mm, better still between 0.5 mm and 1 mm, being for example equal to 0.65 mm.

By “depth of a groove”, we must understand the radial dimension of the groove in relation to the longitudinal axis of the machine.

The first groove may be rectangular in shape. The second groove may be rectangular in shape.

The first groove may have a thickness of between 0.03 mm and 20 mm, preferably between 0.1 mm and 10 mm, better still between 0.2 mm and 2 mm, better still between 0.3 mm and 1 mm, being for example equal to 0.5 mm.

The second groove may have a thickness of between 0.03 mm and 20 mm, preferably between 0.05 mm and 10 mm, better still between 0.1 mm and 2 mm, better still between 0.15 mm and 1 mm, being for example equal to 0.2 mm.

By “thickness of a groove”, we must understand the circumferential dimension of the groove relative to the longitudinal axis of the machine. At least one housing suitable for snap-fastening may comprise at least one rib located above a groove, preferably a first rib located above the first groove and a second rib located above the second groove .

By “rib above a groove”, we must understand a rib radially aligned with the groove but further from the longitudinal axis of the machine than the groove.

The first rib may have an edge aligned with the radial direction of the machine.

The second rib may have an edge inclined relative to the radial direction of the machine, with an inclination which may be between 1° and 90°, preferably between 5° and 60°, better still between 10° and 45°, being for example equal to 19°.

At least one boss of an elastic strip snapped into a housing on the casing or the stator can project from the housing with a height of between 0.05 mm and 15 mm, preferably between 0.05 mm and 5 mm, better between 0.05 mm and 0.5 mm, for example equal to 0.2 mm.

The profile of the housing(s) adapted to snap-fastening allows the lamellae to be easily inserted onto the stator or the casing, as well as to hold the lamellae in place during shrink-fit between the stator and the casing.

Alternatively, at least one elastic strip can be fixed to the stator or the casing by gluing, by welding, by punching, by clipping and/or even by a slide system.

At least one elastic strip carried by the stator can be inserted by sliding when stacking the sheets, said at least one elastic strip being inserted in a slide before assembling the packs of sheets. This can have the advantage of preventing the blades from coming loose from the stator.

Two, three, or even all of the elastic strips can be fixed in the same way in the machine.

Machine The machine can be used as a motor or generator. The machine can be reluctance. It can constitute a synchronous motor or, alternatively, a synchronous generator. As a further variant, it constitutes an asynchronous machine.

The maximum rotation speed of the machine can be high, being for example greater than 10,000 rpm, better still greater than 12,000 rpm, being for example of the order of 14,000 rpm to 15,000 rpm. min, or even 20,000 rpm or 24,000 rpm or 25,000 rpm. The maximum rotational speed of the machine can be less than 100,000 rpm, or even 60,000 rpm, or even less than 40,000 rpm, better still less than 30,000 rpm.

The invention may be particularly suitable for high-power machines.

The machine may also include a rotor. It may comprise a single inner rotor or, alternatively, an inner rotor and an outer rotor, arranged radially on either side of the stator and coupled in rotation.

The machine can be alone in the casing or inserted into a gearbox casing. In this case, it is inserted into a casing which also houses a gearbox.

The stator may include teeth defining notches between them. The notches can be at least partially closed. A partially closed notch makes it possible to create an opening at the level of the air gap, which can be used, for example, to install electrical conductors to fill the notch. A partially closed notch is in particular provided between two teeth which each have polar developments at their free end, which close the notch at least in part.

Alternatively, the notches can be fully closed. By “fully closed notch” we mean notches which are not open radially towards the air gap.

In one embodiment, at least one notch, or even each notch, can be continuously closed on the air gap side by a bridge of material made in one piece with the teeth defining the notch. All the notches can be closed on the air gap side by material bridges closing the notches. The material bridges can be made in one piece with the teeth defining the notch. The stator mass is then devoid of any cut between the teeth and the bridges of material closing the notches, and the The notches are then continuously closed on the air gap side by the bridges of material coming in one piece with the teeth defining the notch.

In addition, the notches can also be closed on the side opposite the air gap by an attached yoke or in one piece with the teeth. The notches are then not opened radially outwards. The stator mass may have no cutout between the teeth and the cylinder head.

In one embodiment, each of the notches has a continuously closed contour. By “continuously closed”, we mean that the notches present a continuous closed contour when observed in cross section, taken perpendicular to the axis of rotation of the machine. You can go all the way around the notch without encountering a cut in the stator mass.

The stator may include coils arranged in a distributed manner in the notches, having in particular electrical conductors arranged in an orderly manner in the notches. By “distributed” we mean that at least one of the coils passes successively through two non-adjacent slots.

The electrical conductors may not be arranged in the slots loosely but in an orderly manner. They are stacked in the notches in a non-random manner, for example being arranged in rows of aligned electrical conductors. The stacking of electrical conductors is for example a stacking according to a hexagonal network in the case of electrical conductors of circular cross section.

The stator may include electrical conductors housed in the notches. At least electrical conductors, or even a majority of electrical conductors, can be pin-shaped, U-shaped or I-shaped. The pin can be U-shaped (“U-pin” in English) or straight, being in form of I (“I-pin” in English).

The electrical conductors can thus form a distributed winding. The winding may not be focused or wound on tooth.

In a variant embodiment, the stator has concentrated winding. The stator may have teeth and coils disposed on the teeth. The stator can thus be wound on teeth, in other words with undistributed winding.

The stator teeth may include polar flares. Alternatively, the stator teeth do not have polar flares.

The stator may include an external carcass surrounding the cylinder head. The stator teeth can be made with a stack of magnetic sheets, each covered with an insulating resin, in order to limit losses through induced currents.

Manufacturing process

The invention also relates to a method of manufacturing a rotating electrical machine, in particular as defined above, comprising the following steps:

- provide the stator mass of the stator comprising a stack of sheets,

- provide the casing,

- insert the elastic strip(s) into one or more housings provided on the stator mass and/or on the casing,

- insert the stator into the casing.

The elastic strip(s) can be inserted into the housing(s) provided on the stator mass or the casing, by gluing, by clipping, by snap-fastening, by welding, by punching, and/or by a slide system.

(a) provide the stator mass of the stator comprising a stack of sheets from which one or more housings are cut,

(b) insert the elastic strip(s) into the housing(s) provided on the stator mass,

(c) insert the stator into the housing.

During step (b) of the manufacturing process, at least one elastic strip can be inserted into a housing provided on the stator mass by snap-fastening and/or at least one elastic strip can be inserted into a housing provided on the stator mass by sliding.

The insertion by snap-fastening of at least one elastic strip into a housing on the stator mass may include the following steps:

(d) position a first side of the elastic strip in a first groove of the housing on the stator,

(d) positioning a second side of the elastic strip in a second groove of the housing, by sliding this second side along an inclined edge of a rib of the housing.

The insertion by sliding of at least one elastic strip into a housing on the stator mass may include the following step:

(f) sliding the elastic strip along an axis parallel to the longitudinal axis of the machine in a housing, when stacking the sheets, using a slide system.

Brief description of the drawings

The invention can be better understood on reading the detailed description which follows, non-limiting examples of its embodiment, and on examining the appended drawing, in which:

[Fig 1] Figure 1 is a schematic and partial perspective view of a rotating electric machine according to the invention,

[Fig 2A] Figure 2A is a schematic and partial perspective view of an elastic strip according to the invention,

[Fig 2B] Figure 2B is a view from another perspective of Figure 2A,

[Fig 2C] Figure 2C is a schematic and partial perspective view of the elastic strip of Figure 2A fixed on the stator,

[Fig 2D] Figure 2D is a cross-sectional view of Figure 2C,

[Fig 2E] Figure 2E is a top view of Figure 2A,

[Fig 3A] Figure 3A is a schematic and partial side view of an alternative embodiment of an elastic strip,

[Fig 3B] Figure 3B is a schematic and partial view of the elastic strip of Figure 3 A fixed on a stator,

[Fig 3C] Figure 3C is a perspective view of Figure 3B,

[Fig 4A] Figure 4A is a schematic and partial perspective view of an elastic strip according to another embodiment,

[Fig 4B] Figure 4B is a schematic and partial cross-sectional view of the elastic lamella of Figure 4A, fixed on a stator,

[Fig 5] Figure 5 is a schematic and partial cross-sectional view of an elastic strip according to another embodiment, fixed on a stator, [Fig 6] Figure 6 is a schematic and partial perspective view of an alternative embodiment of a rotating electric machine,

[Fig 7] Figure 7 is a schematic and partial perspective view of an alternative embodiment of a rotating electric machine,

[Fig 8] Figure 8 is a schematic and partial perspective view of an alternative embodiment of a rotating electric machine.

detailed description

In the figures and in the remainder of the description, the same references represent identical or similar elements.

Figure 1 shows a rotating electric machine according to the invention, comprising a stator 1. The stator 1 comprises a stator mass 2 comprising a stack of sheets. The stator mass 2 has three consecutive packs of sheets, 21, 22 and 23. It also has notches 5.

The central sheet pack 22 has, on its external surface, three housings 3 and carries three elastic strips 4 fixed in these housings. The housings 3, and therefore the elastic strips 4, are angularly evenly distributed around the longitudinal axis of the machine. There is thus an elastic strip 4 every 120° on the central plate pack 22 of the stator mass 2, which makes it possible to distribute the forces of the stator on the casing. The end plate packs, 21 and 23 do not carry elastic strips.

The elastic lamellae 4 are preferably curved to adapt to the rounded shape of the external surface of the stator.

The elastic strips 4 each have three bosses 41a, 41b and 41c, extending along axes parallel to the longitudinal axis of the machine, and a flat surface 42 from which the bosses 41a, 41b and 41c project.

As illustrated in detail in Figures 2A to 2E, the bosses 41a, 41b and 41c are of identical shape, flattened on the top.

In a variant embodiment illustrated in Figures 3A to 3C, the bosses 41a, 41b and 41c are of identical shape, substantially circular and rounded on the top.

As visible in Figure 2B, the bosses 41a, 41b and 41c are hollow. In the embodiment of Figures 2C and 2D, the elastic strips 4 are mounted by sliding in their housings 3 and are held by imprisonment between the packs of end sheets, 21 and 23.

Alternatively, in the embodiment of Figures 3B and 3C, the elastic strips 4 are fixed by snapping into housings 3b.

The elastic strips 4 can be of length L of the order of 36 mm in the case of a stator mass 2 comprising three packs of sheets 21, 22 and 23, as in Figure 1, or of the order of 18 mm in the case of a stator mass comprising six packs of sheets 24a, 24b, 24c, 24d, 24e or 24f, as in Figure 6, and can be of width / of the order of 24 mm. They can be of thickness e of the order of 0.5 mm and can be of height h of the order of 1.9 mm before insertion of the stator into the casing and of the order of 1.7 mm after insertion of the stator in the housing.

The bosses 41a, 41b and 41c can be of length Lb of around 15 mm and can be of width lb of around 5 mm. The distance between the longitudinal axes of two bosses db can be of the order of 8 mm. The height h _p of the bosses, before insertion of the stator into the casing, can be of the order of 1.4 mm.

The housings 3 can have a depth p of the order of 1.7 mm. The bosses 41a, 41b and 41c can project from the housings 3 with a height h _s of the order of 0.2 mm.

The housings 3b can be adapted to snap into place the elastic strips 4, as illustrated in Figures 3B and 3C. The housings 3b comprise a first groove 31 and a second groove 32, opposite each other, extending along axes parallel to the longitudinal axis of the machine. The grooves 31 and 32 can have a depth p _r of the order of 0.65 mm. The second groove 32 can have a thickness e _r of the order of 0.2 mm.

The housings 3b also include a first rib 33 and a second rib 34. The second rib includes in particular an inclined edge 35 relative to the radial direction, with an angle a of the order of 19°. The housings 3b have a diagonal between the lower edge of the first groove 31 and the upper edge of the second rib 34, of the order of 31.1 mm.

We will now describe the manufacturing process of the rotating electric machine, details of which are particularly illustrated in Figures 2C and 2D. In a first step, the central sheet metal package 22 of the stator mass 2 of the stator 1 is provided, comprising the three housings 3.

In a second step, the three elastic strips 4 are mounted by sliding in the housings 3.

Then we provide the packs of end sheets 21 and 23 which are fixed to the central pack of sheets 22, which makes it possible to trap the elastic strips 4 and maintain them in the housings 3.

Finally, we insert stator 1 into the casing.

Alternatively, the method of manufacturing the rotating electric machine, details of which are particularly illustrated in Figures 3B and 3C is as follows.

In a first step, we provide the stator mass 2 of the stator 1, comprising the three consecutive packs of sheets, 21, 22 and 23, and the housings 3b on the central pack of sheets 22 adapted for fixing by snap-fastening.

Secondly, we fix the three elastic strips 4, by snap-fastening, in the three housings 3b according to the following steps, carried out in order:

(a) we position a first side of the elastic strip 4 in the first groove 31 of the housing 3b,

(b) a second side of the elastic strip 4 is positioned in the second groove 32 of the housing 3b, by sliding this second side along the inclined edge 35 of the rib 34 of the housing 3b.

Finally, we insert stator 1 into the casing.

In a variant embodiment, the elastic strips 4 can comprise a single boss 43 longitudinal and centered on the elastic strips 4, as illustrated in Figures 4A, 4B and 5. The boss 43 can be flattened on the top as illustrated in the figures 4A and 4B. The boss 43 can alternatively be circular in shape, rounded on the top, as illustrated in Figure 5.

In the embodiments of Figures 4 A, 4B and Figure 5, the elastic strips 4 are inserted by sliding into the housings 3.

In alternative embodiments, the elastic strips 4 can be fixed on the casing.

They can in particular be fixed on the stator 1 or the casing by welding, punching, clipping or even gluing their edges on the stator 1 or the casing. In alternative embodiments, the stator mass 2 can comprise six packs of sheets 24a, 24b, 24c, 24d, 24e and 24f, as illustrated in Figures 6 to 8.

In the embodiment of Figure 6, each pack of sheets, 24a, 24b, 24c, 24d, 24e or 24f, carries three elastic strips 4 equally distributed angularly around the longitudinal axis of the machine, the angular distance between two 4 consecutive elastic strips of the same pack of sheets, 24a, 24b, 24c, 24d, 24e or 24f, is therefore 120°. The elastic strips each comprise, in this example, three longitudinal bosses 41a, 41b and 41c, and are of length L of around 18 mm. The elastic strips 4 of two consecutive packs of sheets, 24a and 24b, or 24b and 24c, or 24c and 24d, or 24d and 24e, or 24e and 24f, are angularly offset by an angle of 60°. In this exemplary embodiment, the elastic strips 4 are inserted by sliding into the housings 3 and are fixed by clipping. In the case of elastic slats comprising several bosses, and therefore in particular three bosses, fixing by clipping is preferable because it makes it possible to improve the elasticity of the elastic slats.

In the embodiment of Figure 7, the packs of end sheets, 24a and 24f, do not have housings. The four central packs of sheets, 24b, 24c, 24d and 24e, each comprise three housings 3b equally distributed angularly around the longitudinal axis of the machine, the housings 3b being adapted to the snap-fastening of the elastic strips 4. The housings 3b of two consecutive central packs of sheets, 24b and 24c, or 24c and 24d, or 24d and 24e, are angularly offset by an angle of 60°. The stator mass 2 shown in Figure 7 then comprises three different sheet profiles: an identical sheet profile for the end sheet packs 24a and 24f, an identical sheet profile for two non-consecutive central sheet packs 24b and 24d , and an identical sheet profile for the last two packs of sheets 24c and 24e.

Alternatively, the elastic strips 4 can be carried by more than one pack of sheets, in particular by two consecutive packs of sheets.

In the embodiment of Figure 8, the packs of end sheets, 24a and 24f, do not have housings. Each pair of central sheet packs, 24b and 24c, or 24d and 24e, carries three elastic strips 4 each comprising a single longitudinal boss 43 and centered on the elastic strips 4. The elastic strips 4 are in this example of length substantially equal to the sum of the lengths of two consecutive packs of sheets and are fixed in housings 3 extending in length over two packs of consecutive sheets 24b and 24c, or 24d and 24e. The elastic strips 4 carried by the same pair of packs of sheets 24b and 24c, or 24d and 24e, are angularly evenly distributed around the longitudinal axis of the machine. From one pair of packs of sheets to the other 24b and 24c, or 24d and 24e, the elastic strips are offset by an angle of 60°. Of course, the invention is not limited to the embodiments which have just been described. For example, the number of elastic lamellae and/or their shape and/or their arrangement on the stator and/or the casing may vary.

Claims

1. Rotating electric machine comprising:

- a casing,

- a stator (1) comprising a stator mass (2), the stator (1) being arranged in the casing, in particular by hooping,

- one or more elastic strips (4) attached to one of the stator (1) or the casing on its surface facing the other of the stator (1) or the casing, an angular extent of at least one elastic strip (4) around a longitudinal axis of the machine being strictly less than 360°, a length (L) of said at least one elastic strip (4) being strictly less than a length of the stator mass (2), at least an elastic strip (4) being fixed on the stator (1) or on the casing by snap-fastening in a housing adapted to the snap-fastening (3b), or at least one elastic strip carried by the stator being inserted by sliding during the stacking of the sheets, said at least one elastic strip being inserted in a slide before assembling the packs of sheets.

2. Machine according to the preceding claim, at least one elastic strip (4) comprising at least one boss (41a; 41b; 41c; 43).

3. Machine according to one of the preceding claims, at least one elastic strip (4) being positioned so that at least one boss (41a; 41b; 41c; 43) extends along an axis parallel to the longitudinal axis of the machine.

4. Machine according to any one of the preceding claims, the length (L) of at least one elastic strip (4) being between 3 mm and 200 mm, preferably between 3 mm and 110 mm, better still between 3 mm and 70 mm, better between 3 mm and 40 mm, being for example equal to 18 mm or 36 mm.

5. Machine according to any one of the preceding claims, the angular extent of at least one elastic strip (4) being less than or equal to 350°, preferably less than or equal to 300°, better still less than or equal to 250°, even better less than or equal to 200°, even better less than or equal to 150°.

6. Machine according to any one of the preceding claims, at least one elastic strip (4) being at least partially made of a metallic material, of preferably at least partially made of steel or stainless steel or aluminum, better still at least partially made of aluminum-coated steel.

7. Machine according to any one of the preceding claims, elastic strips (4) aligned longitudinally being equally distributed along the longitudinal axis of the machine.

8. Machine according to any one of the preceding claims, elastic strips (4) aligned circumferentially being angularly evenly distributed around the longitudinal axis of the machine.

9. Machine according to any one of claims, at least two elastic strips (4) not aligned circumferentially being offset angularly relative to each other around the longitudinal axis of the machine, in particular by an angle included between 0° and 180°, preferably between 0° and 90°, for example equal to 60°.

10. Machine according to any one of the preceding claims, at least one elastic strip (4) being fixed on the stator (1) or on the casing by snap-fastening in a housing suitable for fixing by snap-fastening (3b).

11. Machine according to the preceding claim, at least one housing adapted for snap-fastening (3b) comprising at least one groove (31; 32), in particular two opposite grooves (31; 32), preferably the second groove (32) being different from the first groove (31).

12. Machine according to one of the two preceding claims, at least one housing adapted for snap-fastening (3b) comprising at least one rib (33; 34) located above a groove (31; 32), in particular a first rib (33) located above the first groove (31) and a second rib (34) located above the second groove (32), the second rib (34) having in particular an inclined edge (35) relative to the radial direction of the machine.

13. Rotating electric machine comprising:

- a casing,

- one or more elastic strips (4) attached to one of the stator (1) or the casing on its surface facing the other of the stator (1) or the casing, an angular extent of at least one elastic strip (4) around a longitudinal axis of the machine being strictly less than 360°, a length (L) of said at least one elastic strip (4) being strictly less than a length of the stator mass (2), at least two elastic strips being aligned circumferentially around the longitudinal axis of the machine.

14. Process for manufacturing a rotating electric machine, according to any one of the preceding claims, comprising the following steps:

(a) provide the stator mass (2) of the stator (1) comprising a stack of sheets from which one or more housings (3; 3b) are cut,

(b) insert the elastic strip(s) (4) into the housing(s) (3; 3b) provided on the stator mass (2),

(c) insert the stator (1) into the housing.

15. Method of manufacturing a rotating electrical machine according to the preceding claim, during step (b) of the manufacturing process, at least one elastic strip (4) being inserted in a housing (3b) provided on the stator mass (2) by snap-fastening, the insertion by snap-fastening of at least one elastic strip (4) into a housing (3b) on the stator mass (2) comprising the following steps:

(d) position a first side of the elastic strip (4) in a first groove (31) of the housing (3b) on the stator (1),

(e) positioning a second side of the elastic strip (4) in a second groove (32) of the housing (3b), by sliding this second side along an inclined edge (35) of a rib (34) housing (3b).

16. Method of manufacturing a rotating electrical machine according to one of the two preceding claims, during step (b) of the manufacturing process, at least one elastic strip (4) being inserted into a housing (3) provided on the stator mass (2) by sliding, the insertion by sliding of at least one elastic strip (4) in a housing (3) on the stator mass (2) comprising the following step: