Rotor for a rotary electric machine

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

[0001] Description

[0002] Title: Rotor of a rotating electric machine

[0003] The present invention claims priority from French application 2205514 filed on June 9, 2022, the content of which (text, drawings and claims) is incorporated herein by reference.

[0004] The present invention relates to rotating electrical machines, and more particularly to the rotors of such machines. The invention relates in particular to the manufacture of the rotor mass of the rotor, and in particular to 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 packages can be angularly offset relative to the adjacent packages (this is referred to as "step skew" in English).

[0005] Technical field

[0006] The invention relates more particularly to synchronous or asynchronous alternating current machines. It relates in particular to traction or propulsion machines for electric (Battery Electric Vehicle) and / or hybrid (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle) motor vehicles, such as private 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 power applications.

[0007] Prior art

[0008] It is known to provide an angular offset between rotor packets. We can then speak of rotor twist.

[0009] It may be useful, particularly in the case of angular offset between rotor packets, to check the angular positioning of the different rotor packets.

[0010] For this purpose, it is possible to carry out the conformity check of the angular offset by analyzing the rotor field lines, 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 packet identification, by making a cut on the outer surface of the packets on the air gap side. However, such a cut can affect the electromagnetic performance of the rotor.

[0011] It is also known from application US 2020 / 321813 to make weld marks on the sheet metal packs of the stator and not the rotor.

[0012] In application CN 107404169, grooves are made on certain packs of sheets in order to carry out a rotor balancing test.

[0013] Furthermore, it is known from application DE 10 2014 208866 to use heat treatment to strengthen the rotor laminations.

[0014] 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.

[0015] There is a need to further improve the control of the angular positioning of the various rotor packages, and in particular to facilitate it and reduce its cost, while improving its precision.

[0016] Summary of the invention

[0017] The invention aims to meet this need and thus has as its subject, according to a first of its aspects, a rotor of a rotating electrical machine, comprising a rotor mass and permanent magnets inserted therein, the rotor mass being composed of a plurality of packets arranged consecutively along an axis of rotation of the rotor, two consecutive packets being in particular angularly offset around the axis of rotation of the rotor by an elementary angle δ relative to each other, at least one packet bearing a mark indicating its angular orientation around the axis of rotation of the rotor.

[0018] The rotor according to the invention is configured to enable the placement of the packets relative to each other to be checked, for example, if necessary, to check the correct angular offset of the packets relative to each other, in particular after the packets have been completely assembled. The packets may or may not be angularly offset around the axis of rotation of the rotor relative to each other.

[0019] Thus, the correct alignment of the packets relative to each other can be checked, especially after the packets have been fully assembled. The invention makes it possible to measure the angular distance between the packets. The measurement can be carried out with greater precision than a magnetic measurement using the invention. It can be carried out both after and before magnetization of the rotor, and without destroying the rotor. It is therefore compatible with any subsequent use of the rotor.

[0020] The rotor according to the invention can be assembled without the mark(s) being used during the assembly process.

[0021] In an assembly line, all rotors or a few selected rotors in the production line can be controlled. The invention can thus make it possible to control the rotor production tool.

[0022] Furthermore, the marking according to the invention can be used to identify the packets, which can be particularly useful when the rotor has several types of packets.

[0023] In one embodiment, at least two consecutive packets of the rotor are angularly offset about the axis of rotation of the rotor by an elementary angle δ relative to each other.

[0024] In the invention, the mark is arranged outside the packet, in particular on the edge thereof. Thus, the positioning of the packets, in particular their angular offset, can always be visible on the rotor, whether it is magnetized or not.

[0025] Statement of the invention

[0026] In one embodiment, the mark may be disposed at the periphery of the rotor, at the air gap. The air gap may be constant. It may not be variable. Alternatively, the air gap may be variable.

[0027] The mark may not be provided at one or both free ends of the rotor, and may not be provided on the faces of the rotor perpendicular to the axis of rotation of the rotor.

[0028] The mark can be between 0.05 and 10 mm wide. The mark width is measured perpendicular to the rotor's axis of rotation.

[0029] The width of the mark may, for example, be less than 5 mm, better still less than 3 mm, or even less than 2 mm, or even better still less than 1 mm. A sufficiently small width improves the angular accuracy of the mark positioning. The width of the mark may, 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 measure the positioning of the corresponding package accurately.

[0030] A tolerance in the positioning of the mark can be of the order of + / - 0.1°, in particular of the order of + / - 0.05°, better of the order of + / - 0.02°.

[0031] A tolerance in the angular positioning of a package may 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.

[0032] The brand may be raised, forming an overhang on the package. Alternatively, the brand may be debossed.

[0033] For example, a mark depth can be less than 5 mm, better still less than 3 mm, or even less than 2 mm, or even better still less than 1 mm. A sufficiently shallow depth ensures that the air gap is not affected. This minimizes the electromagnetic impact of the mark's presence.

[0034] The mark can be optically observable.

[0035] The mark may have a shape chosen from the following list, which is not exhaustive: line, in particular a straight line or not, a curved line, a line forming patterns, in particular a zig-zag, an undulation, a continuous line or not, a line parallel to the axis of rotation of the rotor or inclined relative to it, one or more lines, parallel lines or not.

[0036] A mark on a packet may include several lines parallel to the axis of rotation of the rotor. Two or more consecutive packets may each include a mark including several lines parallel to the axis of rotation of the rotor. When two or more consecutive packets may each include a mark including several lines parallel to the axis of rotation of the rotor, a so-called vernier effect, such as on a caliper, may be obtained, which makes it possible to measure the angular difference between consecutive packets more precisely, without using any measuring means.

[0037] In one embodiment, if the mark comprises multiple lines, the number of lines is different from the number of rotor lamination packs.

[0038] The number of lines can be an indicator of the diversity of package types. For example, one mark can be used for measuring angular offset and other marks can be used to characterize a package type, including their diversity in number of magnets and magnet grade, for example.

[0039] The mark may involve a change in the material of the package. In particular, the mark may result from a change in the metallic material of the package and / or a varnish covering it. The mark may, for example, penetrate the varnish. The change in the metallic material may be a change in the state of the metallic material.

[0040] In the invention, the metallic material of the package is not melted. In the case where the package is formed from a stack of metal sheets, the sheets are distinguished from each other, including at the mark. The mark can be made without melting any material. The mark need not be formed from a molten material.

[0041] In the invention, the mark can be made without deformation of the package.

[0042] The marking can be carried out using a marking laser. The power of the marking laser used can have a peak power of approximately 200 W. The marking can be carried out without heat treatment which could cause demagnetization of the package. The laser used can be chosen from the following list, which is not exhaustive: YOV4, hybrid laser, for example.

[0043] Marking can be carried out without adding material, which avoids any additional pollution.

[0044] The mark can be made by removing material, in particular by a groove or notch made in the package, or by machining.

[0045] Alternatively, the mark may be made by adding material, in particular inkjet, felt-tip pen, paint, resin, in particular colored, this list not being limiting. In one embodiment, the added material may be magnetizable, and be removed after measuring the alignment of the rotor packets, when this measurement is carried out before magnetizing the rotor.

[0046] The mark may not be positioned in a determinate manner relative to a pole of the rotor. Alternatively, the mark may be positioned in a determinate manner relative to a reference, for example a plane passing through a particular point of a pole, in particular the axis of a pole.

[0047] The orientation of the package can be determined by means of a camera positioned on the axis of rotation of the rotor, i.e. observing one face of the package. The positioning of the housings of the permanent magnets in the rotor poles can thus be clearly observed. The mark can be contrasted with the color of the rotor lamination packages, thus allowing the camera to better read the mark. In one embodiment, the color of the mark produced by the laser is black or white in order to contrast with the shades of gray of the rotor lamination packages.

[0048] Marking can be done before assembling the rotor packs, before mounting and shrink-fitting them onto a rotor shaft.

[0049] The mark may be positioned in a determined manner relative to a pole of the rotor. In one embodiment, the mark may be positioned at the center of a pole of the rotor. The rotor may have several marks, each positioned at the center of a pole of the rotor. Alternatively, the mark may be placed at a bridge of material closing a housing of at least one permanent magnet.

[0050] It is possible to adapt the number of marks for inspection. For example, in one embodiment, the rotor has one mark per pole. Such a configuration advantageously eliminates the need for angular marking of the entire rotor.

[0051] Alternatively, the rotor may have a mark on some of the poles, for example on every other pole or every third pole.

[0052] Several rotor packets may each have at least one mark, or even more marks. In one embodiment, all rotor packets may each have at least one mark, or even more marks. Alternatively, the rotor may have one or more unmarked packets.

[0053] Each mark in each package can be positioned relative to the reference. Each mark in each package may not be positioned relative to a mark in another package. This positioning of marks relative to the reference can improve the accuracy of mark positioning.

[0054] Packages

[0055] The rotor mass may have an even number of packets. Alternatively, the rotor mass may have an odd number of packets.

[0056] Two consecutive packets can be angularly offset around the rotor rotation axis by an elementary angle δ. The angular offset between two consecutive packets can be constant when moving along the rotor rotation axis, or alternatively it can vary.

[0057] The rotor mass packets can all be angularly offset in the same direction around the rotor rotation axis.

[0058] 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 with respect 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.

[0059] The rotor mass may comprise a single central packet cut in two by said plane of symmetry.

[0060] 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.

[0061] Alternatively, the rotor mass packets can be angularly offset successively in one direction then in the other, being arranged in a chevron pattern.

[0062] All rotor packets can each have the same length or different lengths.

[0063] Alternatively, two packets may have different lengths. For example, the arrangement of packets in the rotor mass may be such that the packet length may increase and then decrease as Ton moves along the rotation axis, or increase all the way along the rotor, or decrease all the way along the rotor.

[0064] Alternatively, the length of the packets may vary with a sawtooth variation as Ton moves along the rotation axis.

[0065] In one embodiment, the central packet(s) may have a different length than the other packets, for example a shorter or longer length.

[0066] Rotor

[0067] The rotor may include permanent magnets inserted into the rotor mass. The rotor mass may include rotor laminations. The rotor may include permanent magnets, including surface or buried magnets. The rotor may be flux-concentrating. It may include one or more layers of magnets arranged in an I, U, or V shape. The housings for the permanent magnets may be made entirely by cutting into the laminations. Each lamination in the stack of laminations may be a single piece. Alternatively, it may be a wound or squirrel-cage rotor, or a variable reluctance rotor.

[0068] The number of pole pairs p on 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.

[0069] The diameter of the rotor may be less than 600 mm, or even less than 400 mm, better still less than 300 mm, better still less than 200 mm, and greater than 40 mm, better still greater than 60 mm, for example between 80 and 160 mm.

[0070] 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 electrically insulating varnish on their opposite sides before assembly within the stack. Electrical insulation can also be achieved by heat treatment of the sheets, if necessary.

[0071] The rotor may have a shaft on which the rotor mass is placed. The shaft may or may not be smooth.

[0072] 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.

[0073] Alternatively, the rotor comprises a non-magnetic shaft on which the rotor mass is arranged. The shaft may be made at least partly from a material from the following list, which is not exhaustive: steel, stainless steel, titanium or any other non-magnetic material.

[0074] The rotor mass may in one embodiment be arranged directly on the non-magnetic shaft, for example without an intermediate rim. Alternatively, in particular in the case where the shaft is not non-magnetic, the rotor may comprise a rim surrounding the rotor shaft and bearing on the latter.

[0075] The rotor mass may have one or more holes to lighten the rotor, allow it to be balanced or for the assembly of the rotor laminations constituting it. Holes may allow the passage of tie rods holding the laminations together.

[0076] The laminations can be cut in a tool one after the other. They can be stacked and clipped or glued in the tool, in complete packages or sub-packages. The laminations can be snapped onto each other. Alternatively, the package of laminations can be stacked and welded outside the tool. The rotor mass can have an outer contour that is circular or multi-lobed, a multi-lobed shape being useful for example to reduce torque ripples or current or voltage harmonics.

[0077] The rotor may comprise at least one flange which may be disposed at one end of the rotor lamination pack. In one embodiment, the rotor comprises two flanges each disposed at one end of the rotor lamination pack.

[0078] The rotor can be mounted cantilevered or not, relative to the bearings used to guide the shaft.

[0079] Machine and stator

[0080] The invention also relates, independently or in combination with the above, to a rotating electrical machine comprising a rotor as defined above.

[0081] The machine may include a stator having teeth and notches between the teeth, with electrical conductors housed in the notches

[0082] The machine can be used as a motor or as a generator. The machine can be reluctance. It can be a synchronous motor or, alternatively, a synchronous generator. Alternatively, it can be an asynchronous machine.

[0083] The maximum rotation speed of the machine may be high, for example, greater than 10,000 rpm, better still greater than 12,000 rpm, for example, in the order of 14,000 rpm to 15,000 rpm, or even 20,000 rpm or 24,000 rpm or 25,000 rpm. The maximum rotation speed of the machine may 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.

[0084] The invention may be particularly suitable for high-power machines.

[0085] 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.

[0086] The machine can be inserted alone into a housing or inserted into a gearbox housing. In this case, it is inserted into a housing that also houses a gearbox.

[0087] The machine has a stator. The stator has teeth defining notches between them. The stator may have electrical conductors, at least some of the electrical conductors, or even a majority of the electrical conductors, which may be U-shaped or I-shaped.

[0088] Stator mass

[0089] The stator may comprise a stator mass comprising the aforementioned teeth and notches.

[0090] The notches may be at least partially closed. A partially closed notch allows an opening to be provided at the air gap, which can be used, for example, to place electrical conductors for filling the notch. A partially closed notch is in particular provided between two teeth, each of which has pole shoes at their free end, which close the notch at least in part.

[0091] Alternatively, the notches may be fully closed. A "fully closed notch" refers to notches that are not radially open towards the air gap.

[0092] In one embodiment, at least one notch, or even each notch, may 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 may be closed on the air gap side by bridges of material closing the notches. The bridges of material may be made in one piece with the teeth defining the notch. The stator mass is then free of a cutout between the teeth and the bridges of material closing the notches, and the notches are then continuously closed on the air gap side by the bridges of material made in one piece with the teeth defining the notch.

[0093] In addition, the slots can also be closed on the side opposite the air gap by a yoke attached or in one piece with the teeth. The slots are then not open radially outwards. The stator mass can be without a cutout between the teeth and the yoke.

[0094] In one embodiment, each of the notches has a continuously closed contour. By "continuously closed" is meant that the notches have a continuous closed contour when observed in cross-section, taken perpendicular to the axis of rotation of the machine. The notch can be completely circumvented without encountering a cut in the stator mass. The stator mass can be produced by stacking magnetic laminations, the notches having come by cutting the laminations. The stator mass can alternatively be produced by cutting from 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 laminations or the block forming the stator mass.

[0095] The stator can be without magnetic wedges attached to close the notches. This eliminates the risk of these wedges accidentally coming loose.

[0096] The stator may comprise coils arranged in a distributed manner in the slots, in particular having electrical conductors arranged in a row in the slots. By "distributed" is meant that at least one of the coils passes successively through two non-adjacent slots.

[0097] Electrical conductors can form a distributed winding. In this case, the winding is not concentrated or wound on teeth.

[0098] The electrical conductors may not be arranged loosely in the slots but in an orderly manner. They are stacked in the slots in a non-random manner, for example, being arranged in rows of aligned electrical conductors. The stacking of the electrical conductors is, for example, a stacking according to a hexagonal lattice in the case of electrical conductors with a circular cross-section.

[0099] The stator may have electrical conductors housed in the slots. At least some, if not most, of the electrical conductors may be pin-shaped, U-shaped, or I-shaped. The pin may be U-shaped or straight, being I-shaped.

[0100] Each electrical conductor can consist of one or more strands (wire or strand in English). A strand is the most basic unit for electrical conduction. A strand can be round in cross-section, in which case it can be called a 'wire', or flat. Flat strands can be shaped into pins, for example, U-shaped or I-shaped. Each strand is coated with an insulating enamel.

[0101] The electrical conductors may form a single winding, including a whole or fractional winding. A "single winding" means that the electrical conductors are electrically connected together in the stator, and that the connections between the phases are made in the stator, not outside the stator, for example in a terminal box. A winding consists of a number of phases m offset in space in such a way that when they are supplied by a multi-phase current system, they produce a rotating field.

[0102] The winding may be in the invention whole or fractional. The winding may be whole with or without shortening, or in a fractional variant. In one embodiment, the electrical conductors form a fractional winding, in particular with shortened pitch.

[0103] For a fractional winding, the number of slots per pole and per phase is fractional, that is to say that the ratio q defined by Z=Ns / (2 / x / ) is written in the form of an irreducible fraction z / m, z and m being two uninterrupted integers, m being different from 1, where Ns is the number of slots in the stator, q the number of phases in the winding and p the number of pairs of poles.

[0104] The number of stator slots 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 stator poles can be between 2 and 24, or even between 4 and 12, being for example 6 or 8.

[0105] The combination of number of slots / number of stator poles can be chosen from the combinations in the following list, which is not exhaustive: 30 / 4, 42 / 4, 45 / 6, 48 / 8, 63 / 6, 60 / 8, 84 / 8.

[0106] In one embodiment, the combination of number of slots / number of stator poles is 48 / 8. In this case, we have Z=48 / (2*4*3)=2.

[0107] In one embodiment, the combination of number of slots / number of stator poles is 63 / 6. In this case, we have Z=63 / (2*3*3)=7 / 2.

[0108] The winding can be corrugated. The series connection of 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 the same pole are electrically connected to each other so that, for one winding path, the electric current of the phase flows in the electrical conductors while rotating around the axis of rotation of the machine always in one direction. For one winding path, 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.

[0109] The winding can have a single winding path or several winding paths. In an "electrical conductor" the current of the same phase flows through each winding path. By "winding path" we mean all the electrical conductors of the machine which are traversed 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 a single path, the electrical conductors are connected in series. In the case where there are several paths, the electrical conductors of each path are connected in series, and the paths are connected in parallel.

[0110] The electrical conductors can thus form a distributed winding. The winding may not be concentrated or wound on teeth.

[0111] In an alternative embodiment, the stator has concentrated winding. The stator may have teeth and coils arranged on the teeth. The stator may thus be wound on teeth, in other words with non-distributed winding.

[0112] The stator teeth may have pole shoes. Alternatively, the stator teeth are without pole shoes.

[0113] The stator may have an outer casing surrounding the yoke.

[0114] The stator teeth can be made with a stack of magnetic sheets, each covered with an insulating varnish, in order to limit losses due to induced currents.

[0115] Process

[0116] The invention also relates, independently or in combination with the above, to a method of manufacturing a rotor as defined above.

[0117] The invention relates in particular to a method for 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 packets arranged consecutively along an axis of rotation of the rotor, comprising the following steps:

[0118] (a) making a mark on at least one packet to identify its angular orientation around the axis of rotation of the rotor,

[0119] (b) assembling the rotor packets, two consecutive packets being in particular angularly offset around the axis of rotation of the rotor by an elementary angle δ relative to each other.

[0120] In the invention, step (a) is carried out before step (b). In step (b), the packages can be assembled, mounted and shrink-fitted onto a rotor shaft.

[0121] The process may include the following step:

[0122] (c) checking the angular orientation of the rotor packets relative to each other by locating the packet mark(s).

[0123] The angular orientation of the packages can be checked by an optical sensor, a laser, or visually by an operator. 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.

[0124] The mark may be made by adding material. In one embodiment, the added material may be magnetizable.

[0125] In this case, the process may include the following additional step:

[0126] (d) remove material added after measuring rotor packet alignment, especially when this measurement is performed before rotor magnetization.

[0127] Brief description of the drawings

[0128] The invention may be better understood by reading the description which follows, non-limiting examples of its implementation, and by examining the attached drawing, in which:

[0129] [Fig 1] Figure 1 is a schematic and partial side view of a rotor produced in accordance with the invention.

[0130] [Fig 2] Figure 2 is a schematic, partial perspective view of a rotor package of Figure 1.

[0131] [Fig 3a] Figure 3a is a schematic and partial side view of an alternative embodiment.

[0132] [Fig 3b] Figure 3b is a schematic and partial side view of an alternative embodiment.

[0133] [Fig 3c] Figure 3c is a schematic and partial side view of an alternative embodiment.

[0134] [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.

[0135] [Fig 4b] Figure 4b is a schematic and partial perspective view of an alternative embodiment.

[0136] [Fig 4c] Figure 4c is a schematic and partial perspective view of an alternative embodiment.

[0137] [Fig 4d] Figure 4d is a schematic and partial perspective view of an alternative embodiment.

[0138] [Fig 4e] Figure 4e is a schematic and partial perspective view of an alternative embodiment.

[0139] [Fig 4f Figure 4f is a schematic and partial perspective view of an alternative embodiment.

[0140] Detailed description

[0141] Figure 1 illustrates an inner rotor 1 of a rotating electrical machine, also comprising an outer stator (not shown). The stator makes it possible to generate a rotating magnetic field to drive the rotor 1 in rotation, in the case 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.

[0142] The stator has teeth and slots between the teeth, with electrical conductors housed in the slots. The electrical conductors form a fractional or whole winding.

[0143] 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 packets 5 arranged consecutively along the axis of rotation X of the rotor 1, namely four consecutive packets in the example of Figure 1. The packets 5 are each composed of magnetic rotor laminations stacked along the axis X, the laminations being for example identical and exactly superimposed. The magnetic laminations are preferably made of magnetic steel. All grades of magnetic steel can be used.

[0144] Two consecutive packets 5 are angularly offset around the axis of rotation X of the rotor by an elementary angle δ, as illustrated. According to the invention, each of the four packets 5 comprises marks 10 indicating its angular orientation around the axis of rotation of the rotor. The marks 10 are arranged at the periphery of the rotor, at the air gap. Thus, the positioning of the packets, in particular their angular offset, can always be visible on the rotor, as illustrated in Figure 1.

[0145] In this example, each mark 10 has a single straight line extending parallel to the rotor's rotation axis X. Each packet has as many marks 10 as there are rotor poles. The number of rotor poles here is 8, as seen in Figure 2 where a packet 5 has been shown in isolation.

[0146] It can be seen in Figure 2 that each mark 10 is arranged outside the package, on the edge thereof, and that the package 5 comprises 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 comprises one mark per pole.

[0147] The orientation of the package can be determined using a camera positioned on the rotor's X axis of rotation, i.e. observing one side of the package. This allows the positioning of the permanent magnet housings in the rotor poles to be clearly observed.

[0148] As illustrated in Figure 2, each mark of the packet 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 illustrated.

[0149] 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.

[0150] A tolerance in the positioning of the mark 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.

[0151] In alternative embodiments, the mark may have a different shape.

[0152] By way of example, Figure 3a illustrates packets 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 like on a caliper, which makes it possible to measure more precisely the angular difference between the consecutive packets, without using a 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 packets 5 are aligned with each other.

[0153] In the embodiment of Figure 3c, the marks 10 each have a curved shape.

[0154] 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 from each other.

[0155] We will now describe the manufacturing process of rotor 1.

[0156] In a first step (a), a mark 10 is made on at least one packet 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 packets 5.

[0157] In a second step (b), the packets 5 of the rotor are assembled, two consecutive packets 5 being in particular angularly offset around the axis of rotation of the rotor by an elementary angle δ relative to each other.

[0158] Finally, in a third step (c), the angular orientation of the packets 5 of the rotor can be checked relative to each other by identifying the mark(s) 10 of the packets 5. On the marked and mounted rotor 1, the angular distance between the marks of the packets can be measured and thus the angular offset δ between two consecutive packets 5 can be measured.

[0159] The rotor mass may have an even number of packets, as shown in Figure 1.

[0160] 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 δ 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.

[0161] The packets 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 packet 5 cut in two by said plane of symmetry S, as illustrated in figure 4b, with three consecutive packets 5 including a central one.

[0162] Alternatively, the rotor mass may comprise two central packets separated by said plane of symmetry S, as illustrated in figure 4c with four packets 5 including two central ones without angular offset between them.

[0163] In the example of Figure 4d, the rotor has seven consecutive packets 5 arranged in a V, with a central packet.

[0164] All rotor packets can each have the same length, as shown in Figures 1 to 4d.

[0165] Alternatively, two packets may 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.

[0166] Furthermore, it is possible to reproduce the simple V or herringbone pattern several times. As an example, Figure 4f illustrates an example of an embodiment in which the pattern of the embodiment of Figure 1 is reproduced 3 times.

Claims

Demands 1. Rotor (1) of a rotating electrical machine, comprising a rotor mass (3) and permanent magnets inserted therein, the rotor mass (3) 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 angularly offset around the axis of rotation (X) of the rotor by an elementary angle (θ) with respect to each other, at least one pack (5) bearing a mark (10) indicating its angular orientation around the axis of rotation (X) of the rotor, the mark (10) having a width between 0.05 and 10 mm, the mark (10) being positioned in a determined manner with respect to a pole of the rotor (1) or with respect to a reference.

2. Rotor according to the preceding claim, the mark (10) being disposed 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) comprising a modification of the material of the package (5).

5. Rotor according to any one of the preceding claims, the mark (10) being made 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 successively angularly offset in one direction and then in the other, being arranged in V.

8. Rotor according to any one of claims 1 to 5, the packages (5) of the rotor mass (3) being successively angularly offset in one direction and 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) having 6 or 8 poles.

11. Rotating electrical machine comprising: - a rotor (1) according to any one of the preceding claims and - a stator having teeth and notches between the teeth, with electrical conductors 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 packs (5) arranged consecutively along an axis of rotation (X) of the rotor, comprising the following steps: (a) make a mark (10) on at least one pack (5) allowing its angular orientation to be identified 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) relative to each other.

13. A method according to the preceding claim, comprising the following step: (c) control the angular orientation of the packs (5) of the rotor relative to each other by locating the mark or marks (10) of the packs (5).

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