WO2023237827A1

WO2023237827A1 - Rotor for a rotary electric machine

Info

Publication number: WO2023237827A1
Application number: PCT/FR2023/000097
Authority: WO
Inventors: Stephane DESJOURS
Original assignee: Nidec Psa Emotors
Priority date: 2022-06-09
Filing date: 2023-05-11
Publication date: 2023-12-14
Also published as: FR3136611A1

Abstract

The invention relates to a rotor (1) for a rotary electric machine, comprising a rotor mass (3) and permanent magnets inserted into the latter, the rotor mass being composed of a plurality of packs (5) arranged consecutively along an axis of rotation (X) of the rotor, two consecutive packs being in particular offset angularly about the axis of rotation (X) of the rotor by an elementary angle (ô) with respect to one another, at least one pack (5) bearing a mark (10) indicating its angular orientation about the axis of rotation (X) of the rotor.

Description

Title: Rotor of rotating electric machine

The present invention claims priority from French application 2205514 filed on June 9, 2022, the content of which (text, drawings and claims) is herein incorporated by reference.

The present invention relates to rotating electrical machines, and more particularly to the rotors of such machines. The invention concerns in particular the manufacture of the rotor mass of the rotor, and in particular the configuration thereof in the case where it is produced in several packages aligned in the axial direction, for example at least two packages. Each of the packets can be angularly offset relative to adjacent packets (we speak of “step skew” in English).

Technical area

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

It is known to provide an angular offset between rotor packages. We can then speak of rotor twisting.

It may be useful, particularly in the event of angular offset between rotor packages, to check the angular positioning of the different rotor packages.

For this purpose, it is possible to carry out the conformity check of the angular offset by analysis of the field lines of the rotor, but this analysis is not very precise. The rotor can also be dismantled, but with the disadvantage of destroying it in the process. It is also known to use a marking of the packages, by making a cut on the exterior surface thereof on the side of the air gap. However, such cutting may affect the electromagnetic performance of the rotor.

It is also known from application US 2020/321813 to make weld marks on the stator sheet packs and not the rotor.

In application CN 107404169, grooves are made on certain packs of sheets in order to carry out a rotor balancing test.

Furthermore, it is known from application DE 10 2014 208866 to use heat treatment to reinforce the rotor sheets.

It is also known from application US 2018/254675 to modify the magnetic permeability of the rotor at the air gap by deforming the sheets.

There is a need to further improve the control of the angular positioning of the different rotor packages, and in particular to facilitate it and reduce its cost, while improving its precision.

Summary of the invention

The invention aims to meet this need and thus has as its object, according to a first of its aspects, a rotor of a rotating electric machine, comprising a rotor mass and permanent magnets inserted therein, the rotor mass being composed of a plurality of packages arranged consecutively along an axis of rotation of the rotor, two consecutive packages being in particular angularly offset around the axis of rotation of the rotor by an elementary angle ô relative to each other, at minus a package bearing a mark indicating its angular orientation around the axis of rotation of the rotor.

The rotor according to the invention is configured to make it possible to check the placement of the packages relative to each other, for example, if necessary, to check the correct angular offset of the packages relative to each other, in particular after the complete assembly of the packages. packages. The packages may or may not be angularly offset around the axis of rotation of the rotor relative to each other.

Thus, we can check the correct alignment of the packages with respect to each other, particularly after the complete assembly of the packages. The invention makes it possible to measure the angular distance between the packets. The measurement can be carried out thanks to the invention with better precision than a magnetic measurement. It can be carried out both after and before magnetization of the rotor, and without destroying the rotor. It is thus compatible with any subsequent use of the rotor.

The rotor according to the invention can be assembled without the brand(s) being used during the assembly process.

In an assembly line, you can control all the rotors or a few selected rotors in the production line. The invention can thus make it possible to control the rotor production tool.

Furthermore, the marking according to the invention can be used to identify the packets, which can in particular be useful when the rotor includes several types of packets.

In one embodiment, at least two consecutive rotor packages are angularly offset around the axis of rotation of the rotor by an elementary angle δ relative to each other.

In the invention, the mark is placed outside the package, in particular on the edge thereof. Thus, the positioning of the packages, in particular their angular offset, can always be visible on the rotor, whether it is magnetized or not.

Presentation of the invention

In one embodiment, the mark can be placed on the periphery of the rotor, at the level of the air gap. The air gap can be constant. It may not be variable. Alternatively, the air gap can be variable.

The mark may not be placed at one or both of the free ends of the rotor, and may not be placed on the faces of the rotor perpendicular to the axis of rotation of the rotor.

The mark can be between 0.05 and 10 mm wide. The width of the mark is measured perpendicular to the axis of rotation of the rotor.

The width of the mark can for example be less than 5 mm, better still less than 3 mm, even less than 2 mm, better still less than 1 mm. A sufficiently small width makes it possible to improve the angular precision of the positioning of the mark. The width of the mark can for example be greater than 0.05 mm, better still greater than 0.1 mm, or even greater than 0.5 mm. A sufficient width makes it easier to read the mark by an optical control means, in order to enable the positioning of the corresponding package to be measured with precision.

A tolerance in the positioning of the brand can be of the order of +/- 0.1°, in particular of the order of +/- 0.05°, better of the order of +/- 0.02° .

A tolerance in the angular positioning of a package can be of the order of +/- 0.8°, in particular of the order of +/- 0.4°, better of the order of +/- 0, 2°. In an exemplary embodiment, the angular tolerance in the angular positioning of a package is of the order of +/- 0.4°, for a rotor diameter of 150 mm.

The mark may be raised, forming an extra thickness on the package. Alternatively, the mark may be recessed.

A depth of the mark can for example be less than 5 mm, better still less than 3 mm, even less than 2 mm, better still less than 1 mm. A sufficiently shallow depth ensures that the air gap is not affected. This helps minimize the electromagnetic impact of the brand’s presence.

The mark may be optically observable.

The mark may have a shape chosen from the following list, which is not exhaustive: line, in particular rectilinear line or not, curved line, line forming patterns, in particular in zig-zag, undulation, continuous line or not, line parallel to the axis of rotation of the rotor or inclined relative to it, one or more lines, lines parallel or not.

A package mark may include several lines parallel to the axis of rotation of the rotor. Two or more consecutive packages may each include a mark comprising several lines parallel to the axis of rotation of the rotor. When two or more consecutive packages can each include a mark comprising several lines parallel to the axis of rotation of the rotor, we can obtain for example a so-called vernier effect like on a caliper, which makes it possible to measure the angular deviation more precisely between consecutive packets, without using any measuring means.

In one embodiment, if the mark has several lines, the number of lines is different from the number of packs of rotor sheets.

The number of traits can be an indicator of the diversity of packet types. For example, a mark can be used for measuring angular offset and other Marks can be used to characterize a type of package, in particular their diversity in number of magnets and grade of magnets, for example.

The mark may include a modification of the material of the package. In particular, the mark may result from a modification of the metallic material of the package and/or a varnish covering it. The mark can, for example, penetrate the varnish. Changing the metal material may be a change in the state of the metal material.

In the invention, the metallic material of the package is not melted. In the case where the package is made up of a stack of metal sheets, the sheets can be distinguished from each other, including at the brand level. The mark can be made without melting any material. The mark may not be formed from molten material.

In the invention, the mark can be produced without deformation of the package.

The mark can be made using a marking laser. The power of the marking laser used can have a peak power of around 200 W. The marking can be carried out without heat treatment which risks causing demagnetization of the package. The laser used can be chosen from the following list, which is not exhaustive: YOV4, hybrid laser, for example.

Marking can be carried out without adding material, which avoids any additional pollution.

The mark can be made by removing material, in particular by a groove or notch made in the package, or by machining.

Alternatively, the mark can be made by adding material, in particular inkjet, felt, paint, resin, in particular colored resin, this list not being exhaustive. In one embodiment, the added material may be magnetizable, and be removed after measuring the alignment of the rotor packages, when this measurement is carried out before magnetizing the rotor.

The mark may not be positioned in a determined manner relative to a pole of the rotor. Alternatively, the mark can be positioned in a determined manner relative to a reference, for example a plane passing through a particular point of a pole, in particular the axis of a pole.

The orientation of the package can be identified by means of a camera placed on the axis of rotation of the rotor, that is to say observing one side of the package. We can thus carefully observe the positioning of the permanent magnet housings in the rotor poles. The mark can be contrasted with the color of the rotor plate packs, allowing for better reading of the mark by the camera. In one embodiment, the color of the mark made by the laser is black or white in order to contrast with the shades of gray of the rotor sheet packs.

Marking can be done before assembling the rotor packages, before mounting and shrinking them onto a rotor shaft.

The mark can be positioned in a determined manner relative to a pole of the rotor. In one embodiment, the mark can be positioned in the center of a pole of the rotor. The rotor may have several marks, each positioned at the center of a rotor pole. Alternatively, the mark can be placed at the level of a material bridge closing a housing of at least one permanent magnet.

It is possible to adapt the number of marks to the check. For example, in one embodiment, the rotor has one mark per pole. Such a configuration advantageously makes it possible to avoid the need to carry out angular registration of the complete rotor.

Alternatively, the rotor may have a mark on some of the poles, for example on every second pole or every third pole.

Several rotor packages can each have at least one mark, or even several marks. In one embodiment, all the rotor packages can each include at least one mark, or even several marks. Alternatively, the rotor may include one or more unmarked packages.

Each mark of each package can be positioned relative to the reference. Each mark in each packet may not be positioned relative to a mark in another packet. This positioning of brands in relation to the reference can improve the precision of brand positioning.

Packages

The rotor mass can include an even number of packets. Alternatively, the rotor mass may include an odd number of packets.

Two consecutive packages can be angularly offset around the axis of rotation of the rotor by an elementary angle ô. The angular offset between two consecutive packets can be constant when moving along the axis of rotation of the rotor, or alternatively it can vary.

The rotor mass packages can all be angularly offset in the same direction around the axis of rotation of the rotor.

Alternatively, they can be angularly offset successively in one direction then in the other, being arranged in a V. They can be arranged in a V, being offset symmetrically relative to a plane of symmetry perpendicular to the axis of rotation of the rotor. An advantage of the V configuration is that it allows the axial force to be minimized.

The rotor mass may comprise a single central package cut in two by said plane of symmetry.

Alternatively, the rotor mass may comprise two central packages separated by said plane of symmetry. The two central packages may not be angularly offset from each other.

As a further variant, the packages of the rotor mass can be angularly offset successively in one direction then in the other, being arranged in chevrons.

All rotor packages can each have the same length or different lengths.

Alternatively, two packets may have different lengths. For example, the arrangement of the packets in the rotor mass can be such that the length of the packets can increase then decrease as Ton moves along the axis of rotation, or increase all along the rotor, or decrease all along the rotor.

As a further variation, the length of the packets may vary with a sawtooth variation as Ton moves along the axis of rotation.

In one embodiment, the central packet(s) may have a different length from the other packets, for example a shorter or longer length.

Rotor

The rotor may include permanent magnets inserted into the rotor mass. The rotor mass may include rotor plates. The rotor may include permanent magnets, including surface or buried magnets. The rotor can be flux concentrated. It can include one or more layers of magnets arranged in an I, U or V shape. The housings for the permanent magnets can be made entirely by cutting into the sheets. Each sheet of the stack of sheets can be in one piece. Alternatively, it may be a wound or squirrel cage rotor, or a variable reluctance rotor.

The number of pairs of poles p in the rotor is for example between 1 and 24, being for example 1, 2, 3, 4, 5 or 6. The rotor can have 6 or 8 poles.

The diameter of the rotor can be less than 600 mm, even less than 400 mm, better less than 300 mm, better still less than 200 mm, and greater than 40 mm, better greater than 60 mm, being for example between 80 and 160 mm.

Each sheet is for example cut from a sheet of magnetic steel or containing magnetic steel, for example steel 0.1 to 1.5 mm thick. The sheets can be coated with an electrical insulating varnish on their opposite sides before their assembly within the stack. Electrical insulation can still be obtained by heat treatment of the sheets, if necessary.

The rotor may include a shaft on which the rotor mass is placed. The shaft may or may not be smooth.

The shaft can be made of a magnetic material, which advantageously reduces the risk of saturation in the rotor mass and improves the electromagnetic performance of the rotor.

Alternatively, the rotor comprises a non-magnetic shaft on which the rotor mass is arranged. The shaft can be made at least in part from a material from the following list, which is not exhaustive: steel, stainless steel, titanium or any other non-magnetic material.

The rotor mass can in one embodiment be placed directly on the non-magnetic shaft, for example without an intermediate rim. Alternatively, particularly in the case where the shaft is not non-magnetic, the rotor may include a rim surrounding the rotor shaft and bearing on the latter.

The rotor mass may include one or more holes to lighten the rotor, allow it to be balanced or for the assembly of the rotor plates constituting it. Holes can allow the passage of tie rods holding the sheets together.

The sheets can be cut in a tool one after the other. They can be stacked and clipped or glued into the tool, in complete packs or sub-packs. The sheets can be snapped onto each other. Alternatively, the sheet pack can be stacked and welded outside the tool. The rotor mass may have an external contour which is circular or multilobed, a multilobed shape being useful for example for reducing torque ripples or current or voltage harmonics.

The rotor may include at least one flange which may be placed at one end of the pack of rotor sheets. In one embodiment, the rotor comprises two flanges each disposed at one end of the pack of rotor sheets.

The rotor can be mounted cantilevered or not, in relation to the bearings used to guide the shaft.

Machine and stator

The invention also relates, independently or in combination with the above, to a rotating electric machine comprising a rotor as defined above.

The machine may include a stator having teeth and notches between the teeth, electrical conductors being housed in the notches

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 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 inserted alone into a casing or inserted into a gearbox casing. In this case, it is inserted into a casing which also houses a gearbox.

The machine has a stator. The latter has teeth defining notches between them. The stator may include electrical conductors, at least part electrical conductors, or even a majority of electrical conductors, which may be U-shaped or I-shaped.

Stator mass

The stator may include a stator mass comprising the aforementioned teeth and notches.

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 notches are then continuously closed on the side of the air gap 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 have 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 mass can be produced by stacking magnetic sheets, the notches being made by cutting the sheets. The stator mass can alternatively be produced by cutting into a mass of sintered or agglomerated magnetic powder. The closing of the notches on the air gap side is obtained by bridges of material coming in one piece with the rest of the sheets or the block forming the stator mass.

The stator may be devoid of magnetic shims for closing the notches. This eliminates the risk of accidental detachment of these wedges.

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 can form a distributed winding. The winding is in this case not concentrated or wound on tooth.

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).

Each electrical conductor may include one or more strands (“wire” or “strand” in English). By “strand” we mean the most basic unit for electrical conduction. A strand can have a round cross section, we can then speak of a ‘thread’, or flat. The flat strands can be shaped into pins, for example in a U or I shape. Each strand is coated with an insulating enamel.

The electrical conductors can form a single winding, in particular whole or fractional. By “single winding”, we mean that the electrical conductors are electrically connected together in the stator, and that the connections between the phases are made in the stator, and not outside the stator, for example in a terminal box. . A winding is made up of a number of phases m offset in space by such so that when powered by a multi-phase current system, they produce a rotating field.

The winding can be in the invention whole or fractional. The winding can be whole stepwise with or without shortening, or in a fractional variant. In one embodiment, the electrical conductors form a fractional winding, in particular with a shortened pitch.

For a fractional winding, the number of notches per pole and per phase is fractional, that is to say the ratio q defined by Z=Ns/(2/x/) is written in the form of a irreducible fraction z/m, z and m being two unharmed integers, m being different from 1, where Ns is the number of stator notches, q the number of phases of the winding and p the number of pairs of poles.

The number of stator notches can be between 18 and 96, better between 30 and 84, being for example 18, 24, 27, 30, 36, 42, 45, 48, 54, 60, 63, 72, 81 , 92, 96, better being 48 or 60 or 63. The number of poles of the stator can be between 2 and 24, or even between 4 and 12, being for example 6 or 8.

The combination number of notches/number of poles of the stator can be chosen from the combinations in the following list, which is not restrictive: 30/4, 42/4, 45/6, 48/8, 63/6, 60/8, 84/8.

In one embodiment, the combination number of notches/number of poles of the stator is 48/8. In this case we have Z=48/(2*4*3)=2.

In one embodiment, the number of notches/number of stator poles combination is 63/6. In this case we have Z=63/(2*3*3)=7/2.

The winding can be corrugated. The series connection of the electrical conductors can be done in so-called corrugated winding. By "corrugated winding" is meant a winding in which the electrical conductors of the same phase and of the same pole are electrically connected to each other in such a way that, for a winding path, the electric current of the phase circulates in the electrical conductors rotating around the axis of rotation of the machine always in one direction. For a winding track, the electrical conductors of the same phase and the same pole do not overlap when observed perpendicular to the axis of rotation of the machine.

The winding may have a single winding path or several winding paths. In an “electric conductor” the current of the same phase circulates through winding path. By “winding path”, we mean all of the electrical conductors of the machine which are carried by the same electric current of the same phase. These electrical conductors can be connected together in series or in parallel or in series-parallel. In the case where there is only one channel, the electrical conductors are connected in series. In the case where there are several channels, the electrical conductors of each channel are connected in series, and the channels are connected in parallel.

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 varnish, in order to limit losses through induced currents.

Process

The invention also relates, independently or in combination with the above, to a method of manufacturing a rotor as defined above.

The subject of the invention is in particular a method of manufacturing a rotor of a rotating electrical machine, in particular as defined above, comprising a rotor mass and permanent magnets inserted therein, the rotor mass being composed of a plurality of packages arranged consecutively along an axis of rotation of the rotor, comprising the following steps:

(a) make a mark on at least one package making it possible to identify its angular orientation around the axis of rotation of the rotor,

(b) assemble the rotor packages, two consecutive packages being in particular angularly offset around the axis of rotation of the rotor by an elementary angle ô relative to each other.

In the invention, step (a) is carried out before step (b). In step (b), we can assemble the packages, mount them and shrink them onto a rotor shaft.

The process may include the following step:

(c) check the angular orientation of the rotor packages relative to each other by identifying the package mark(s).

Control of the angular orientation of the packages can be carried out by an optical sensor, or a laser, or even visually by an operator. The visual inspection can be carried out with a mask, for example a paper mask, or a projector. This mask or projector can be used to display the limits of the angular offset tolerance.

The mark can be made by adding material. In one embodiment, the added material may be magnetizable.

In this case, the process may include the following additional step:

(d) remove the added material after measuring the alignment of the rotor packages, particularly when this measurement is carried out before magnetizing the rotor.

Brief description of the drawings

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

[Fig 1] Figure 1 is a schematic and partial side view of a rotor produced in accordance with the invention.

[Fig 2] Figure 2 is a schematic and partial perspective view of a package of the rotor of Figure 1.

[Fig 3a] Figure 3a is a schematic and partial side view of an alternative embodiment.

[Fig 3b] Figure 3b is a schematic and partial side view of an alternative embodiment.

[Fig 3c] Figure 3c is a schematic and partial side view of an alternative embodiment.

[Fig 3d] Figure 3d is a schematic and partial side view of an alternative embodiment. [Fig 4a] Figure 4a is a schematic and partial perspective view of an alternative embodiment.

[Fig 4b] Figure 4b is a schematic and partial perspective view of an alternative embodiment.

[Fig 4c] Figure 4c is a schematic and partial perspective view of an alternative embodiment.

[Fig 4d] Figure 4d is a schematic and partial perspective view of an alternative embodiment.

[Fig 4e] Figure 4e is a schematic and partial perspective view of an alternative embodiment.

[Fig 4f Figure 4f is a schematic and partial perspective view of an alternative embodiment.

detailed description

We illustrate in Figure 1 an internal rotor 1 of a rotating electric machine, also comprising an external stator not shown. The stator makes it possible to generate a rotating magnetic field driving the rotor 1 in rotation, in the context of a synchronous motor, and in the case of an alternator, the rotation of the rotor induces an electromotive force in the electrical conductors of the stator .

The stator has teeth and notches between the teeth, with electrical conductors housed in the notches. Electrical conductors form a fractional or whole winding.

The rotor 1 shown in Figure 1 comprises a rotor magnetic mass 3 extending axially along the axis of rotation X of the rotor, this rotor mass being formed by a plurality of packages 5 arranged consecutively along the axis of rotation X of the rotor 1, namely four consecutive packages in the example of Figure 1. The packages 5 are each composed of magnetic rotor sheets stacked along the axis The magnetic sheets are preferably made of magnetic steel. All grades of magnetic steel can be used.

Two consecutive packages 5 are angularly offset around the axis of rotation X of the rotor by an elementary angle ô, as illustrated. In accordance with the invention, each of the four packages 5 has marks 10 indicating its angular orientation around the axis of rotation of the rotor. The marks 10 are arranged on the periphery of the rotor, at the level of the air gap. Thus, the positioning of the packages, in particular their angular offset, can always be visible on the rotor, as illustrated in Figure 1.

In this example, each mark 10 has a single rectilinear line extending parallel to the axis of rotation X of the rotor. Each package has as many 10 marks as there are rotor poles. The number of rotor poles here is 8, as visible in Figure 2 where a package 5 has been shown in isolation.

We see in Figure 2 that each mark 10 is arranged outside the package, on the edge thereof, and that the package 5 includes marks 10 positioned in a determined manner relative to a pole of the rotor. Each mark 10 is here positioned at the center of a pole of the rotor, and the rotor has one mark per pole.

The orientation of the package can be identified by means of a camera placed on the axis of rotation X of the rotor, that is to say observing one side of the package. We can thus clearly observe the positioning of the permanent magnet housings in the rotor poles.

As illustrated in Figure 2, each mark of the package 5 is positioned relative to a reference R in a determined manner, the reference R being for example a plane passing through a particular point of a pole, in particular the axis of a pole , as shown.

The marks 10 of this embodiment have a width which is the width of the line, measured perpendicular to the axis of rotation of the rotor, which is of the order of 0.1 mm.

A tolerance in the positioning of the brand can be of the order of +/- 0.02°. A tolerance in the angular positioning of a package can be of the order of +/- 0.4°, for a rotor diameter of 150 mm.

In alternative embodiments, the mark may have a different shape.

By way of example, we have illustrated in Figure 3a packages 5 each having a mark formed by three lines parallel to the axis of rotation of the rotor, which can make it possible to obtain a so-called vernier effect as on a foot slide, which allows the angular difference between consecutive packages to be measured more precisely, without using measuring means. In the embodiment of Figure 3b, the marks 10 are each formed by a single rectilinear line, inclined relative to the axis of rotation of the rotor. The lines of the marks 10 of the different packages 5 are aligned with each other.

In the embodiment of Figure 3c, the marks 10 each have a curved shape.

Finally, in the example of Figure 3d, the marks 10 are each formed of several lines parallel to the axis of rotation of the rotor 1, namely three or four lines, which are offset relative to each other.

We will now describe the manufacturing process of rotor 1.

In a first step (a), a mark 10 is made on at least one package 5 making it possible to identify its angular orientation around the axis of rotation X of the rotor. In the example described with reference to Figures 1 and 2, several marks 10 are made on each of the four packages 5.

In a second step (b), the packages 5 of the rotor are assembled, two consecutive packages 5 being in particular angularly offset around the axis of rotation of the rotor by an elementary angle ô relative to each other.

Finally, in a third step (c), we can control the angular orientation of the packages 5 of the rotor relative to each other by identifying the mark(s) 10 of the packages 5. On the rotor 1 marked and mounted, we can measure the angular distance between the marks of the packets and thus measure the angular offset ô between two consecutive packets 5.

The rotor mass can have an even number of packets, as shown in Figure 1.

Alternatively, the rotor mass may comprise an odd number of packets, as illustrated in Figure 4a, where the rotor comprises three packets 5 all identical, angularly offset by an angle ô all in the same direction around the axis of rotation X of the rotor. The angular offset between two consecutive packets is here constant when moving along the axis of rotation of the rotor.

The packages 5 can be angularly offset successively in one direction then in the other, being arranged in a V and offset symmetrically with respect to a plane of symmetry S perpendicular to the axis of rotation X of the rotor. The rotor mass can comprise a single central package 5 cut in two by said plane of symmetry S, as illustrated in Figure 4b, with three consecutive packages 5 including a central one.

Alternatively, the rotor mass can comprise two central packages separated by said plane of symmetry S, as illustrated in Figure 4c with four packages 5 including two central ones without angular offset between them.

In the example of Figure 4d, the rotor has seven consecutive packages 5 arranged in a V, with a central package.

All rotor packages can each have the same length, as illustrated in Figures 1 to 4d.

Alternatively, two packets can have different lengths, as shown in Figure 4e. In this embodiment, the two central packets have a length 12 greater than the length 11 of the other packets.

Furthermore, it is possible to reproduce the simple V or herringbone pattern several times. As an example, Figure 4f illustrates an embodiment in which the pattern of the embodiment of Figure 1 is reproduced 3 times.

Claims

1. Rotor (1) of a rotating electric machine, comprising a rotor mass (3) and permanent magnets inserted therein, the rotor mass (3) being composed of a plurality of packages (5) arranged consecutively along 'an axis of rotation (X) of the rotor, two consecutive packages being in particular angularly offset around the axis of rotation (X) of the rotor by an elementary angle (ô) relative to each other, at least a package (5) bearing a mark (10) indicating its angular orientation around the axis of rotation (X) of the rotor, the mark (10) having a width of between 0.05 and 10 mm, the mark (10) being positioned in a determined manner relative to a pole of the rotor (1) or relative to a reference.

2. Rotor according to the preceding claim, the mark (10) being arranged at the periphery of the rotor (1), at the level of the air gap.

3. Rotor according to any one of the preceding claims, a mark (10) of a package (5) comprising several lines parallel to the axis of rotation (X) of the rotor.

4. Rotor according to any one of the preceding claims, the mark (10) including a modification of the material of the package (5).

5. Rotor according to any one of the preceding claims, the mark (10) being produced by means of a marking laser.

6. Rotor according to any one of the preceding claims, the packages (5) of the rotor mass (3) being angularly offset all in the same direction around the axis of rotation (X) of the rotor.

7. Rotor according to any one of claims 1 to 5, the packages (5) of the rotor mass (3) being angularly offset successively in one direction then in the other, being arranged in a V.

8. Rotor according to any one of claims 1 to 5, the packages (5) of the rotor mass (3) being angularly offset successively in one direction then in the other, being arranged in chevrons.

9. Rotor according to any one of the preceding claims, all the packages (5) of the rotor (1) each having the same length.

10. Rotor according to any one of the preceding claims, the rotor (1) comprising 6 or 8 poles.

11. Rotating electric machine comprising:

- a rotor (1) according to any one of the preceding claims and

- a stator comprising teeth and notches between the teeth, electrical conductors being housed in the notches.

12. Method for manufacturing a rotor (1) of a rotating electrical machine, in particular according to any one of claims 1 to 10, comprising a rotor mass (3) and permanent magnets inserted therein, the rotor mass ( 3) being composed of a plurality of packages (5) arranged consecutively along an axis of rotation (X) of the rotor, comprising the following steps:

(a) making a mark (10) on at least one package (5) making it possible to identify its angular orientation around the axis of rotation (X) of the rotor,

(b) assemble the packages (5) of the rotor (1), two consecutive packages (5) being in particular angularly offset around the axis of rotation of the rotor by an elementary angle (ô) one relative to the other.

13. Method according to the preceding claim, comprising the following step:

(c) check the angular orientation of the rotor packages (5) relative to each other by identifying the mark(s) (10) of the packages (5).