Arrangement for a rotor of an electric machine

Abstract

The invention relates to an arrangement (3) for an electric machine (2) comprising a rotating shaft (4) and a rotor (5), wherein the rotor comprises a stack (8) of laminations each extending in a plane perpendicular to the axis (A) of the rotating shaft, wherein the stack (8) comprises radial extensions (20) spaced apart by slots (10) so as to form a star in overall shape, and wherein the rotor (5) comprises two axial ends (51, 52), wherein each axial end (51; 52) comprises a generally star-shaped guide similar to the stack (8), wherein each guide comprises arms that extend radially so as to axially extend the radial extensions (20) of the stack (8), wherein each arm comprises a winding surface for a winding (6) and a contact face that extends in a plane perpendicular to the axis of the rotating shaft, wherein the contact face makes contact with the stack, and wherein the contact face is substantially opposite the winding surface.

Description

Description Title of the invention: Arrangement for an electric machine rotor.

[0001] The invention relates to an arrangement for a salient-pole wound-rotor electric machine rotor. The invention further relates to an electric machine comprising such an arrangement. The invention also relates to a vehicle comprising such an arrangement or such an electric machine. Finally, the invention relates to a method for assembling such an arrangement.

[0002] An electric machine typically includes a wound rotor with salient poles. Such a rotor consists of cut metal laminations, each extending perpendicularly to the rotor's axis of rotation and stacked one on top of the other. The winding must be insulated from this stack of laminations. Therefore, an insulator is placed between the winding and the laminations. This insulator is usually a thin sheet. In the case of an electric motor, in particular, the rotor's rotational speed is very high, generating considerable centrifugal force. A spacer is then generally placed between the insulator and the laminations to hold the insulator in position during the machine's operation.

[0003] Typically, a guide or cover called a "coil head guide" extends along each side of such a stack of laminations. These guides on either side of the stack facilitate the winding of the coil at each pole.

[0004] However, during the insertion of the shim parallel to the rotor's axis of rotation, the shim comes into contact with the insulation and catches it. In this situation, the insulation is displaced along part of the stroke required for the shim's placement. The insulation then becomes bent and / or protrudes beyond its intended area, preventing it from providing complete electrical insulation. This situation necessitates removing the shim, detaching the insulation, repositioning or even replacing the insulation, reinstalling the shim, and finally verifying that the assembly is correct this time.

[0005] The objective of the present invention is to provide an arrangement that overcomes the above drawbacks. Furthermore, the arrangement allows for easy, reliable, and durable rotor assembly. Summary of the invention

[0006] To achieve this objective, the invention relates to an arrangement for an electrical machine comprising: - a rotating shaft, - a rotor extending around the rotating shaft, the rotor comprising a stack of laminations, each extending in a plane perpendicular to the axis of the rotating shaft, the stack comprising radial extensions spaced by notches so as to form an overall star shape, the rotor comprising two axial ends, each axial end comprising a guide generally in the shape of a star similar to the stack, each guide comprising arms extending radially so as to axially extend the radial extensions of the stack, each arm comprising a winding surface for a winding and a contact face extending in a plane perpendicular to the axis of the rotating shaft, the contact face coming into contact with the stack, the contact face being substantially opposite to the winding surface,each winding being arranged in contact or opposite each winding surface of each arm of each guide and surrounding each adjacent radial extension so as to create a rotor pole, each arm comprising a first surface extending substantially radially between the contact face on one side of the arm and the winding surface and a second surface extending substantially radially between the contact face and the winding surface on the other side of the arm, the first and second surfaces being opposite a winding, each arm comprising a radial end, the radial end comprising a third surface of the arm extending perpendicularly from the first surface and a fourth surface extending perpendicularly from the second surface, the third and fourth surfaces extending orthoradially in opposite directions,the third and fourth surfaces extending in a direction parallel to the axis relative to the first and second surfaces, in the opposite direction to the radial extensions of the stack.

[0007] The third surface may include an axial stop extending in a plane perpendicular to the axis of rotation and the fourth surface may include an axial stop extending in the same plane perpendicular to the axis of rotation.

[0008] The arrangement may include a first insulator, in particular of NOMEX material (registered trademark), the first insulator being able to extend against at least a part of the third surface of an arm and at least a part of the fourth surface of an adjacent arm of the guide at one axial end of the rotor, and being able to extend against at least a part of the third surface of an arm and at least a part of the fourth surface of an adjacent arm of the guide at the other axial end of the rotor.

[0009] The arrangement may include at least one wedge arranged within the notch between two adjacent radial extensions of the rotor, F at least one wedge being able to be in contact with the first insulator.

[0010] The arrangement may include a second insulator, in particular made of NOMEX material (registered trademark), the second insulator being able to extend in particular against the first surface of an arm and against the second surface of an adjacent arm, the second insulator being able to extend at the level of a bottom of the notch between the two adjacent arms at the level of an axial end of the rotor, and being able to extend in particular against the first surface of an arm and against the second surface of an adjacent arm, the second insulator being able to extend at the level of a bottom of the notch between the two adjacent arms at the level of the other axial end of the rotor.

[0011] A winding can be wound so as to be in contact with the first and second insulators to avoid any contact of the winding with the rotor stack.

[0012] The first insulator can partially overlap the second insulator at the third and fourth surfaces of each arm.

[0013] Two wedges can be arranged between two adjacent radial extensions, one of the two wedges being able to be beveled so as to facilitate its insertion between two adjacent radial extensions.

[0014] The invention further relates to an electrical machine, in particular a traction and / or propulsion motor for a vehicle, comprising an arrangement as defined above.

[0015] The invention also relates to a vehicle, in particular a motor vehicle, comprising an electrical machine as defined above or an arrangement as defined above.

[0016] The invention also relates to a method for assembling an arrangement as defined above, comprising: - a step of placing the first insulator on at least part of the third surface and on at least part of the fourth surface of each arm of the two guides arranged on either side of the rotor substantially simultaneously with the placement of this same first insulator on the radial extensions extending between these two guides, the first insulator being placed up to the contact or substantially up to the contact of each axial stop, - followed by a step of inserting at least one shim between two adjacent arms of a guide at one axial end of the rotor, then between two radial extensions, possibly up to between two arms of the guide at the other axial end of the rotor. Presentation of the figures

[0017] These objects, features and advantages of the present invention will be described in detail in the following non-limiting description of the embodiment, with reference to the accompanying figures, among which:

[0018] Figure [Fig. 1] is a schematic view of a vehicle according to one embodiment of the invention.

[0019] Figure [Fig. 2] is a perspective view of an electric machine rotor according to one embodiment of the invention.

[0020] Figure 3 is a detailed perspective view of an arm of a coil head guide of the electric machine according to one embodiment of the invention.

[0021] Fig. 4 is a detailed section of the electric machine along a plane perpendicular to the axis of rotation of the electric machine passing through radial extensions according to an embodiment of the invention.

[0022] Figure 5 is a perspective view of a reel head guide according to one embodiment of the invention.

[0023] Figure 6 is another perspective view of the coil head guide according to the embodiment of the invention. Detailed description

[0024] As illustrated in [Fig. 1], a vehicle 1, preferably a motor vehicle, comprises at least one electric machine 2. The electric machine 2 is advantageously an electric motor. The vehicle 1 comprises, for example, a hybrid propulsion and / or traction means, namely, equipped with at least one internal combustion engine (not shown) and at least one electric motor 2. Alternatively, the vehicle 1 comprises, for example, an electric propulsion and / or traction means comprising at least one electric motor 2. Thus, preferably, the electric machine 2 is a traction and / or propulsion motor for the vehicle. Preferably, the vehicle 1 includes a battery for storing electrical energy (not shown). The vehicle 1, or the electric machine 2, comprises an arrangement 3.

[0025] As illustrated in [Fig. 2], the arrangement 3 for the electric machine 2 includes a rotating shaft 4 having an axis A. The arrangement 3 further includes a wound rotor 5. The rotor 5 extends around the rotating shaft 4. When the electric motor 2 is operating, the rotor 5 rotates around the axis A of the rotating shaft 4. As illustrated in Figures 2 and 4, the rotor 5 includes a stack 8. The stack 8 comprises cut sheets, each extending in a plane perpendicular to the axis A of the rotating shaft 4. The sheets, preferably metallic and made of steel, constituting the stack 8 extend against each other, without any gap between two adjacent sheets. The sheets are cut and stacked so as to form poles 7. salients. By "salient," we mean that each pole extends radially from the axis A of the rotation shaft 4. More precisely, as illustrated in [Fig. 2], the stack 8 therefore comprises radial extensions 20. Each radial extension 20 creates a pole 7. Two adjacent radial extensions 20 are separated by a notch, gap, or space 10. In other words, a succession of radial extensions 20 and notches 10 are created by the stack 8 of sheets so as to form an overall star shape. Preferably, the number of radial extensions 20 is even, and the number of notches 10 is also even and identical to the number of radial extensions 20.

[0026] As illustrated in [Fig. 2], the rotor 5 comprises two axial ends 51, 52. Each axial end 51, 52 includes a guide 30, also called a "coil head guide," illustrated in particular in Figures 3, 5, and 6. A guide 30 has an overall star shape similar, or even identical, to the stack 8 in a plane perpendicular to the axis A of rotation of the shaft 4. In other words, an external contour of a section of a guide 30 intended to come into contact with the stack 8 is identical, or at least very close, to the section of the stack 8. Preferably, sections of the stack 8 taken perpendicular to the axis A are all identical or substantially identical along the length of the stack in a direction parallel to the axis A.

[0027] More specifically, as illustrated in Figures 5 and 6, each guide 30 comprises arms 31. Each guide 30 comprises the same number of arms 31 as the number of radial extensions 20 of the stack 8 (and therefore the number of poles 7). Indeed, each arm 31 extends radially so as to axially extend each radial extension 20 of the stack 8. Thus, once the two guides 30 are mounted on either side of the stack 8, the radial extensions 20 are extended by the arms 31, and the notches 10 of the stack 8 are extended by openings, notches, or gaps 310. Each opening 310 extends between two adjacent arms 31 of a guide 30. Furthermore, as illustrated in Figures 3, 5, and 6, each arm 31 includes a winding surface 316 for a coil or winding 6. Such a winding is preferably made of copper wire.Preferably, the winding surface 316 of a single arm 31 comprises two rounded and / or chamfered areas or surfaces, as illustrated in particular in [Fig. 6]. Optionally, as illustrated, grooves or grooves are provided on each winding surface to facilitate the placement of the winding 6. As illustrated in Figures 3 and 5, each guide 30, and preferably each arm of a single guide 30, comprises a contact face or reference face 32 extending in a plane perpendicular to the axis A of the rotating shaft 4. This contact face 32 is intended to come into contact with, or bear against, the stack 8. Thus, each contact face 32 of each guide 30 comes into contact with each end. of the stack 8. This yields the unwound rotor 5. The contact face 32 is, at least partially, substantially opposite the winding surface 316. Thus, the contact face 32 is not in contact with the winding 6. Indeed, each winding 6 is arranged in contact with, or opposite, each winding surface 316 of each arm 31 of each guide 30 and surrounds each adjacent radial extension 20. As illustrated in [Fig. 2], each winding 6 wound around two opposing arms on either side of the stack 8 and around each radial extension 20 of the stack 8 creates a pole 7 of the rotor 5. Although eight poles 7, i.e., four pairs, are shown, more or fewer pole pairs could possibly be used.

[0028] More specifically, as illustrated in Figures 3 and 6, each arm 31 comprises a first surface 311 extending substantially radially between the contact face 32 on one side 317 of the arm 31 and the winding surface 316. Each arm 31 also comprises a second surface 312 extending substantially radially between the contact face 32 and the winding surface 316 on the other side 318 of the arm 31. The first and second surfaces 311, 312 are therefore opposite a winding 6. As illustrated in particular in [Fig. 3], each arm 31 comprises a radial end or top or foot 33. The radial end 33 comprises a third surface 313 of the arm 31. The third surface 313 extends perpendicularly from the first surface 311. The radial end 33 includes a fourth surface 314 extending perpendicularly from the second surface 312.Thus, the third and fourth surfaces 313, 314 extend orthoradially in opposite directions. The third and fourth surfaces 313, 314 protrude axially relative to the first and second surfaces 311, 312 in the opposite direction to the radial extensions 20 of the stack 8. As illustrated in [Fig. 5], for example, each arm 31 has a plane PB of symmetry passing through the axis A of rotation of the rotor shaft 4. For example, the radial end 33 of each arm 31 is also symmetrical with respect to this same plane PB. In the case of an even number of arms, the plane of symmetry PB is valid for two arms 31 arranged symmetrically with respect to the axis A.

[0029] As illustrated in particular in Figures 3 and 6, the third surface 313 includes an axial stop, edge, or recess 323. The axial stop 323 extends in a plane perpendicular to the axis A of rotation. The fourth surface 314 also includes an axial stop 324 extending in this same plane perpendicular to the axis A of rotation. In fact, preferably the end 33, or even the entirety of each arm, is symmetrical with respect to a respective plane PB.

[0030] The arrangement 3 further includes a first insulator 61, or notch-closing insulator 10. Preferably, the material of the first insulator 61 is NOMEX (registered trademark). The first insulator 61 extends against, or at the same level as, or opposite of at least a portion of the third surface 313 of an arm 31 and therefore against, or at the level of, or opposite a portion 21 of the radial extension 20 of the stack 8 opposite, as illustrated in [Fig. 4]. This same first insulator 61 also extends against, or at the level of, or opposite at least a portion of the fourth surface 314 of an adjacent arm of the same guide 30 and therefore against, or at the level of, or opposite a portion 21 of the radial extension 20 of the stack 8 opposite, as illustrated in [Fig. 4]. This location of the first insulator 61 is valid for both the guide of the axial end 51 of the rotor 5 and the guide of its other axial end 52.

[0031] The arrangement 3 further includes at least one shim 40, or notch shim, arranged within the notch 10 between two adjacent radial extensions 20 of the rotor 5, as illustrated in [Fig. 2] (before insertion) and in [Fig. 4]. The shim 40 is in contact with the first insulator 61. The shim 40 preferably has a substantially triangular cross-section along a plane perpendicular to the axis A of rotation of the shaft 4. For example, the shim 40 includes an orifice 45 passing through the longest dimension of the shim, i.e., an axial direction parallel to the axis A. Once the winding(s) 6 are wound around two adjacent radial extensions 20 and consequently around two adjacent arms of each guide, the shim 40 can lock the first insulator 61 against each winding 6. As illustrated in [Fig.[4], the wedge 40 comprises a first face or surface 41 that comes into contact with the first insulator 61 and presses it against a winding 6 of a radial extension 20 of the stack. As illustrated in [Fig. 4], the wedge 40 also comprises a second face or surface 42 that comes into contact with the first insulator 61 and presses it against a winding 6 of an adjacent radial extension 20 of the stack. Thus, a single wedge 40 allows the first insulator 61 to be pressed simultaneously against two adjacent radial extensions 20, separated only by the notch or gap 10.

[0032] The arrangement 3 further includes a second insulator 62, or notch bottom insulator 10. Preferably, the material of the second insulator 62 is also NOMEX (registered trademark). The second insulator 62 preferably extends against, or opposite, the first surface 311 of one arm 31 and against the second surface 312 of another adjacent arm 31. The same applies to the stack 8, so that parts or areas 22 of each radial extension 20 are in contact with the second insulator 62, as illustrated in [Fig. 4]. In addition, the second insulator 62 extends at a bottom 11 of the notch 10 between the two adjacent radial extensions 20 concerned. As illustrated in [Fig. 3], the second insulator 62 extends further over at least part of the third surface 313 of one end 33 of an arm. This same second insulator 62 then also extends over at least part of the fourth surface 314 of one end 33 of an adjacent arm. Note that theThe second insulator 62 also extends to the bottom 315 of the opening 310 between the two neighboring arms concerned. Thus, the same second insulator 62 extends over a part of the third surface 313 of one arm, over the first surface 311 of that same arm, in the bottom 315 of the opening 310, over the second surface 312 of the neighboring arm and finally over a part of the fourth surface 314 of that adjacent arm. The same applies to the stack 8, the second insulator 62 extending over a part 23 of a radial extension 20 (extension of the third surface 313 or the fourth surface 314), then over the part 22 (extension of the first surface 311 or the second surface 312 of a guide 30), and between the two radial extensions 20 adjacent at the level of the bottom 11 (extension of the bottom 315 between two neighboring arms 31), as illustrated in [Fig.4].Thus, a single second insulator 62 generally covers one side 317 of an arm 31, the other side 318 substantially opposite the neighboring arm, and this on both guides 30 arranged on either side of the rotor. This same second insulator 62 covers the faces or surfaces 23, 22 of a radial extension 20, the bottom 11 between two radial extensions 20 and the faces 22, 23 of the neighboring radial extension 20, as illustrated in [Fig. 4].

[0033] The winding or coil 6 is preferably wound so as to be in contact with the first and second insulators 61, 62. As a reminder, as is particularly visible in [Fig. 4], the same first insulator 61 and the same second insulator 62 extend within a notch 10 between two radial extensions 20 of the stack 8. The same is true in the two axial extensions of the stack 8, that is to say at each end 51, 52 comprising a guide 30. Indeed, the same first insulator 61 and the same second insulator 62 extend within the opening 310 between two arms 31. In summary, in the case of four pairs of poles 7, i.e., eight poles, as in the illustrated embodiment, eight first insulators 61 and eight second insulators 62 are arranged. Indeed, in such an eight-pole rotor, eight spaces or notches 10 are present and it results that eight openings 310 are present at each guide 30.Thanks to the insulators 61, 62, any contact between the winding 6 and the laminations of the stack 8 of the rotor 5 is avoided.

[0034] Advantageously, the first insulator 61 overlaps at least partially the second insulator 62 at the third and fourth surfaces 313, 314 of each radial end 33 of an arm 31. Preferably, the second insulator 62 is in contact with the third and fourth surfaces 313, 314, and the first insulator 61 comes into contact with the second insulator 62 at this point. The same then applies at the radial extensions 20 of the stack 8. The second insulator 62 is in contact with the surface 23 of the radial extension 20, and the first insulator 61 comes into contact with the second insulator at this point (see [Fig. 4]).

[0035] Preferably, two shims 40 are used per zone comprising a notch 10 and an opening 310 on each of the two guides 30. In other words, for a rotor 5 with four pole pairs, sixteen shims 40 are used. Thus, two shims 40 are placed, inserted, in a direction parallel to the axis A of rotation of the rotor between two adjacent radial extensions 20, next to each other (see thick arrow in [Fig. 2]). Advantageously, as illustrated in [Fig. 2], the shim inserted first, or the single shim, comprises front sections 43 taken perpendicular to the axial direction (direction of insertion of the shims) having a smaller area than the rear sections, following the direction of insertion of the shim. Optionally, each wedge 40 includes a beveled part, and / or the apexes of sections arranged at the front of the wedge are rounded, chamfered, flattened so as to facilitate the introduction of the front of the wedge.

[0036] Advantageously, the first surfaces 311 and / or the second surfaces 312 and / or the third surfaces 313 and / or the fourth surfaces 314 are flat or substantially flat. Optionally, the bottoms 315 between two arms 31 are flat or substantially flat.

[0037] Advantageously, the parts 23, 22 of the radial extensions 20 are flat or substantially flat surfaces. Optionally, the bottoms 11 of the notches 10 are flat or substantially flat.

[0038] An execution method for assembling arrangement 3 will now be described.

[0039] First, a stack 8 and two guides 30 are obtained. Each guide 30 is placed, or even fixed, for example by radial interference, on either side of the stack 8, the arms 31 of each guide being in respective extension of the radial extensions 20 of the stack 8. Optionally, the shaft 4 is arranged, inserted within the rotor part 5 thus composed, for example by having mounted bearings on the shaft so as to facilitate its subsequent integration in pivot joint relative to a casing or housing (not illustrated).

[0040] Next, we proceed to a step of applying the second insulator 62 to part 23 of a radial extension 20, to part 22, to the bottom 11 then to part 22 of the adjacent radial extension then to part 23 of this adjacent radial extension 20 ([Fig.4]). In other words, the second insulator 62 is placed within the notch 10. Simultaneously, for example, this same insulator 62 is placed on one of the guides 30, namely on a portion of the third surface 313 of an arm extending from one of the radial extensions, as well as on the first surface 311 and on the base 315, then on the second surface 312 of an arm extending from the other radial extension, and then on a portion of the fourth surface 314 of this arm 31. The same procedure is followed on the second guide 30 by placing this same insulator 62, if possible simultaneously or substantially simultaneously. This operation is repeated eight times so as to place eight second insulators 62 for a rotor with four pole pairs 7. For example, this step of placing the second insulator 62 is done automatically by a machine.

[0041] Next, a winding step is carried out, winding the wire, preferably copper, so as to obtain the winding 6 surrounding both an arm 31 of a guide 30, the radial extension 20 of the stack 8 opposite this arm, and the arm 31 of the other guide 30 also opposite the stack 8. This winding operation is repeated eight times, that is, for each pole 7 being manufactured. Again, preferably, this step is performed automatically by a machine.

[0042] Next, the first insulation layer 61 is applied to the third surface 313, or at the level of the third surface 313, for example, by partially overlapping the second insulation layer 62. Specifically, this application of the first insulation layer 61 is made against the winding 6 of an arm 31, for example between the second insulator 62 and the winding 6. In this step, the first insulator 61 is also placed on the fourth surface 314, or at the level of the fourth surface 314, for example, by partially overlapping the second insulator 62 of an adjacent arm, next to and against the winding 6 of this adjacent arm. The same is done, for example, simultaneously, on the other side of the rotor, on the other guide 30. Note that care is preferably taken to place this first insulator 61 up to the contact, or substantially up to the contact, of each axial stop 323, 324 illustrated in Figures 3, 5, and 6. Simultaneously, if necessary, this same first insulator 61 is placed at the level, opposite the parts 21 of the corresponding radial extension 20 of the stack. This operation is repeated eight times so as to place eight first insulators 61 for a rotor with four pole pairs 7.

[0043] Next, we proceed to an insertion step of at least one shim 40, preferably two shims one behind the other, within an opening 310 between two adjacent arms 31 of a guide 30 of the axial end 51 of the rotor 5 for example. The insertion of the shims is then carried out by axial translation between the two corresponding radial extensions 20, that is to say in the notch 10 opposite the opening 310. Finally, this insertion is carried out between two adjacent arms 31 of the other guide 30 arranged at the other axial end 52 of the rotor 5. This operation is repeated eight times so as to place the sixteen shims, in the case where two shims are inserted between two poles, for a rotor with four pairs of poles 7. As mentioned previously, the front of the shim has a smaller cross-section than the rear part of the shim in order to facilitate and limit friction between the front of the shim and the contact areas during insertion.

[0044] In summary, the solution involves an arrangement for the wound rotor coil head guides that enhances electrical insulation. Two guides are provided, one on each side of the rotor, to ensure optimal winding of each pole of the machine. Electrical 2. Thus, the solution allows the copper windings 6 of the rotor 5 to be electrically isolated from the other surrounding parts, notably the stack of laminations 8 and the retaining wedges 40. Indeed, the insulating paper 62 at the bottom of slot 10 and the insulating paper 61 at the end of slot 10 are placed in each slot 10 of the rotor 5. For a rotor comprising eight poles 7 as illustrated, eight slots 10 receiving windings are therefore insulated by the first and second insulators 61, 62.

[0045] Most importantly, as illustrated in [Fig.3], arrangement 3 allows each insulator 61, 62 an optimal location to ensure electrical insulation. More precisely, the insulator 62 extends axially outwards from the rotor to an axial end 621 at the bottom 315 of the opening 310, the first surface 311 and the third surface 313. Note that the axial end 621 of the second insulator 62 does not extend to the axial stop 323 of the third surface 313. A gap Y, along the axial direction, i.e. parallel to the axis A of the rotor shaft, is provided between the axial end 621 of the second insulator 62 (coming substantially into contact with an axial stop 34) and the axial stop 323 at the third surface 313. The gap or space Y has a value, for example, between 1 mm and 4 mm, or even between 2 mm and 3 mm. Thus, the first insulator 61 extends axially outwards from the rotor to its axial end 611.This axial end 611 of the first insulator 61 is preferably coincident, or substantially coincident, with the axial stop 323. In other words, the first insulator 61 is placed to come into contact or substantially into contact with the axial stop 323 and this on each guide 30, at least before the insertion of the wedges 40.

[0046] Similarly, the insulator 62 extends axially outward from the rotor to an axial end (not shown) of the second surface 312 and the fourth surface 314. Note that the axial end of the second insulator 62 does not extend to the axial stop 324 of the fourth surface 314. A gap Y, along the axial direction, i.e., parallel to the axis A of the rotor shaft, is also provided between the axial end of the second insulator 62 and the axial stop at the level of the fourth surface 314. The gap Y again has a value, for example, between 1 mm and 4 mm, or even between 2 mm and 3 mm. More precisely, the insulator 61 also extends axially outward from the rotor to an axial end. This axial end of the first insulator 61 is coincident, or substantially coincident, with the axial stop 324 of the fourth surface 314.In other words, the first insulator 61 is placed to come into contact or substantially into contact with the axial stop 324 and this on each guide 30, at least before the insertion of the shims 40.

[0047] In other words, each insulator 61, 62 is positioned, placed, wedged, according to the axial direction, on support surfaces.

[0048] Indeed, the second insulator 62 is positioned axially against an axial stop or bearing surface 34 provided on each arm 31 at the level of the first surface 311. Another axial stop is also provided, at the same axial dimension, at the level of the second surface 312. Thus, the axial end 621 of the second insulator is placed in contact, or substantially in contact, with the axial stop 34 of the first surface 311 on the arm of a guide. Similarly, this same second insulator is placed up to the corresponding axial stop on the second surface 312 of the adjacent arm of the same guide. On the other side, preferably after being placed within the notches 10 of the stack 8, the axial end 621 of this second insulator is placed in contact, or substantially in contact, with the axial stop 34 of the first surface 311 on an arm of the other guide.Similarly, this same second insulator 62 is placed up to the corresponding axial stop on the second surface 312 of the adjacent arm of the other guide.

[0049] As a reminder, the first insulator 61 is placed after the winding stage or, possibly, during the winding stage.

[0050] In summary, the axial positioning of the insulators 61, 62 is ensured respectively by the two bearing surfaces or stops 323, 34 provided on each arm 31 of each coil head guide 30 arranged each at an axial end 51; 52 of the rotor 5.

[0051] As a reminder, the shims 40 are inserted into the notches 10 and into the openings or spaces 310 separating the corresponding arms of each guide in order to hold the copper windings 6 in position during rotor operation, particularly at high rotational speeds.

[0052] Because the first insulator 61 extends axially over the third surface 313, and then over the fourth surface 314, beyond the stop 34, i.e., up to the stop 323, a margin, an "extra length," equal to the value of the clearance Y along the axial direction is obtained on each side of the rotor. Thus, during the shim insertion step, if the first insulator 61 is pulled along by friction with the shim, this is not a problem. Indeed, the value of the distance Y is determined to be greater than the maximum potential translational stroke of the insulator(s) displaced by their direct contact with at least one shim during insertion. This prevents any wrinkling of the insulator(s). It should be noted that the "extra length" of the first insulator 61 is, in total, twice the value Y since a guide is present at each of the two ends 51, 52 of the rotor.This is especially preferable when the wedge(s) on one side of a pole are inserted in a first SI direction and the wedge(s) on the other side of the same pole are inserted in a second S2 direction, opposite to the first SI direction (see [Fig.2]).

[0053] Thus, the first insulator 61 can be translated, offset, displaced, hooked during the insertion of a wedge towards the first end 51 by a maximum value equal to to the excess length corresponding to the Y offset. Indeed, on the other side, at end 52, the guide includes, on each arm, stops 323 and 324, and the first insulator is pre-positioned up to these stops. Thus, a margin equal to the value of the Y offset at end 52 can be absorbed, displaced, and reappear, possibly in the form of folds, at the first end 51 without affecting the electrical insulation. In other words, the solution tolerates a displacement of the first insulator 61 during the insertion of shims 40, or even one or more folds. The same applies when inserting a wedge towards the second end 52. The solution therefore avoids any electrical insulation defect between the winding 6 and one end of the stack 8 made of steel in particular, due to insufficient protrusion of the insulator 61. By avoiding such an insulation defect, potential electrical malfunctions of the machine 2 are eliminated.Obviously, such malfunctions, particularly in the case of an electric traction and / or propulsion motor of a vehicle, are unacceptable since they could cause premature wear of the motor, or even a motor failure, leading to the immobilization of the vehicle.

[0054] By preventing incorrect placement of the insulation, this solution also eliminates the need to remove the shims, the insulation itself, and then replace the insulation and shims—a process that is time-consuming, tedious, and expensive, especially since such operations are generally performed manually in the factory. Furthermore, after such an insulation replacement or adjustment, a visual inspection is carried out. There may still be a risk of incorrect installation, for example, excessive displacement of an insulation element leading to a defect. In this case, a further adjustment step is required. This solution therefore eliminates one or more time-consuming and costly adjustment operations.

[0055] In summary, the solution guarantees correct and reliable overhang of the insulators 61, meeting functional requirements despite their translation due to friction caused by the insertion of the notch shims 40. The axial support area or stop 323, 324 of the first insulator 61 is offset by a value Y relative to the axial support area or stop 34 of the second insulator 62. It should be noted that the axial stop 34 extends in a plane perpendicular, or nearly perpendicular, to the axis of rotation A of the rotor. Thus, it becomes possible to position or install an insulator 61 with a length twice the value Y along the axial direction, ensuring that the insulator 61 remains correctly positioned under all circumstances, even if the insulator is translated during the insertion of the shims.

[0056] The solution is particularly inexpensive and easy to implement, with only the 30 guides requiring slight manufacturing modifications. As mentioned previously, the solution eliminates the need for rework, which is generally Manual adjustments are time-consuming, tedious, and costly. Furthermore, by avoiding these adjustments, potential rotor damage that would eventually necessitate replacement is prevented. As mentioned, this solution improves reliability and guarantees consistent distances, areas, or insulation surfaces between the copper windings and the rotor stack.

[0057] As a point of note, the solution therefore achieves the desired objective of ensuring the reliability of the electrical insulation of a rotor during its assembly and has the advantage of being able to be used on all types of electrical machines with wound salient poles.

Claims

Demands

1. Arrangement (3) for an electrical machine (2) comprising: - a rotating shaft (4), - a rotor (5) extending around the rotating shaft (4), the rotor (5) comprising a stack (8) of laminations each extending in a plane perpendicular to the axis (A) of the rotating shaft (4), the stack (8) comprising radial extensions (20) spaced by notches (10) so as to form an overall star, the rotor (5) comprising two axial ends (51, 52), each axial end (51; 52) comprising a guide (30) overall in the shape of a star similar to the stack (8), each guide (30) comprising arms (31) extending radially so as to axially extend the radial extensions (20) of the stack (8), each arm (31) comprising a winding surface (316) for a winding (6) and a contact face (32) extending in a plane perpendicular to the axis (A) of the rotation shaft (4), the contact face (32) coming into contact with the stack (8), the contact face (32) being substantially opposite to the winding surface (316),Each winding (6) is arranged in contact with or opposite each winding surface (316) of each arm (31) of each guide (30) and surrounds each adjacent radial extension (20) so as to create a pole (7) of the rotor (5). Each arm (31) comprises a first surface (311) extending substantially radially between the contact face (32) on one side (317) of the arm (31) and the winding surface (316), and a second surface (312) extending substantially radially between the contact face (32) and the winding surface (316) on the other side (318) of the arm (31). The first and second surfaces (311, 312) are opposite a winding (6). Each arm (31) comprises a radial end (33), the radial end (33) comprising a third surface (313) of the arm (31) extending perpendicularly from the first surface (311) and a fourth surface (314) extending perpendicularly from the second surface (312), the third and fourth surfaces (313,314) extending orthoradially in opposite directions, the third and fourth surfaces (313, 314) extending in a parallel direction, to the axis (A) with respect to the first and second surfaces (311, 312) in the opposite direction to the radial extensions (20) of the stacking (8).

2. Arrangement (3) according to the preceding claim, characterized in that the third surface (313) comprises an axial stop (323) extending in a plane perpendicular to the axis (A) of rotation and in that the fourth surface (314) comprises an axial stop (324) extending in the same plane perpendicular to the axis (A) of rotation.

3. Arrangement (3) according to any one of the preceding claims, characterized in that the arrangement (3) comprises a first insulator (61), in particular of NOMEX material (registered trademark), the first insulator (61) extending against at least a part of the third surface (313) of an arm (31) and at least a part of the fourth surface (314) of an adjacent arm of the guide (30) at the level of an axial end (51) of the rotor (5), and extending against at least a part of the third surface (313) of an arm (31) and at least a part of the fourth surface (314) of an adjacent arm of the guide (30) at the level of the other axial end (52) of the rotor (5).

4. Arrangement (3) according to the preceding claim, characterized in that the arrangement (3) comprises at least one wedge (40) arranged within the notch (10) between two adjacent radial extensions (20) of the rotor (5), the at least one wedge (40) being in contact with the first insulator (61).

5. Arrangement (3) according to the preceding claim, characterized in that the arrangement (3) comprises a second insulator (62), in particular of NOMEX material (registered trademark), the second insulator (62) extending in particular against the first surface (311) of an arm (31) and against the second surface (312) of an adjacent arm, the second insulator (62) extending at the level of a bottom (11) of the notch (10) between the two adjacent arms at the level of an axial end (51) of the rotor (5), and extending in particular against the first surface (311) of an arm (31) and against the second surface (312) of an adjacent arm, the second insulator (62) extending at the level of a bottom (11) of the notch (10) between the two adjacent arms at the level of the other axial end (52) of the rotor (5).

6. Arrangement (3) according to the preceding claim, characterized in that a winding (6) is wound so as to be in contact with the first and second insulators (61, 62) to avoid any contact of the winding (6) with the stack (8) of the rotor (5).

7. Arrangement (3) according to any one of claims 5 or 6, characterized in that the first insulator (61) partially overlaps the second insulator (62) at the third and fourth surfaces (313, 314) of each arm (31).

8. Arrangement (3) according to any one of claims 4 to 6, characterized in that two wedges (40) are arranged between two adjacent radial extensions (20), one of the two wedges (40) being beveled so as to facilitate its insertion between two adjacent radial extensions (20).

9. Electric machine (2), in particular traction and / or propulsion motor for a vehicle, characterized in that it comprises an arrangement (3) according to any one of the preceding claims.

10. Vehicle (1), in particular motor vehicle, characterized in that it comprises an electrical machine (2) according to the preceding claim or an arrangement (3) according to any one of claims 1 to 8.

11. A method for assembling an arrangement (3) according to claims 1 to 3 and according to any one of claims 4 to 8, characterized in that it comprises: - a step of placing the first insulator (61) on at least a part of the third surface (313) and on at least a part of the fourth surface (314) of each arm (31) of the two guides (30) arranged on either side of the rotor (6) substantially simultaneously with the placement of this same first insulator (61) on the radial extensions (20) extending between these two guides (30), the first insulator (61) being placed up to the contact or substantially up to the contact of each axial stop (323, 324), - followed by a step of inserting at least one shim (40) between two adjacent arms (31) of a guide (30) of an axial end (51; 52) of the rotor (5), then between two radial extensions (20), possibly up to between two arms (31) of the guide (30) of the other axial end (51; 52) of the rotor (5).

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