Coil insulator intended to be positioned around a tooth of a stator or of a rotor of an electric machine

Abstract

The invention relates to a coil insulator (6) intended to be positioned around a tooth (3) of a stator or of a rotor (1), this coil insulator (6) comprising a body (8) comprising walls (9) extending in a first direction (D1) and forming a wrapper intended to surround a tooth (3), as well as a first flange (10) and a second flange (11) extending from opposite edges of the walls (9) and defining therewith a groove (13) intended to receive the windings (7) of a coil; at least one of the flanges has a thinned region (15) that is thinned in the first direction (D1) such that the flanges in this thinned region (15) are separated by a distance greater than the distance separating them outside of this region, said thinned region (15) being located in the immediate vicinity of an end wall (9d) of the body (8).

Description

Description Title of the invention: Coil insulator intended to be positioned around a tooth of a stator or rotor of an electrical machine

[0001] The invention relates to a coil insulator for positioning around a tooth of a stator or rotor of an electrical machine.

[0002] As is known per se, rotating electrical machines comprise a stator, secured to a casing, and a rotor, secured to a shaft. The rotor may be secured to a driving and / or driven shaft and may belong to a rotating electrical machine in the form of an alternator or an electric motor.

[0003] In axial flux electric machines, the stator and rotor are arranged so that the electromagnetic flux between the stator and the rotor is essentially parallel to the rotor shaft. Most axial flux electric machines comprise several stators and / or rotors, each having a disc shape, these elements being separated, along the axial direction of the rotor shaft, by interstices called air gaps.

[0004] Usually, the rotor and the stator comprise a plurality of teeth corresponding to windings typically constituted by wires which are wound around an electrical insulator surrounding a tooth body made of laminated sheet metal.

[0005] A common solution for stator manufacturing is to manufacture the teeth separately. A well-known manufacturing process, called spindle winding, involves rotating the tooth body, topped with an insulator, so as to wind the wire around the insulator, the wire also being guided into the correct position by the shape of the insulator.

[0006] This process, however, presents difficulties when it is necessary to change the position of the wire during turns and when crossing the wire at each layer change because the wire used is difficult to handle. These changes in position and crossing of the wire are even more difficult to achieve when they take place at one end of the insulation, the latter being often narrow. These difficulties lead to a loss of compactness of the winding to the detriment of the efficiency of the coil.

[0007] The present invention aims to overcome all or part of the aforementioned drawbacks.

[0008] To this end, the invention relates to a coil insulator intended to be positioned around a tooth of a stator or a rotor of an electrical machine, this coil insulator comprising: - a body comprising walls extending in a first direction and forming an envelope intended to surround a stator or rotor tooth, as well as a first rim and a second rim extending perpendicularly or substantially perpendicularly to the first direction from edges opposite walls and defining with them a groove intended to receive the windings of a coil, the body having in a plane perpendicular to the first direction, a length extending in a second direction and a width extending in a third direction, the second and third directions being perpendicular to each other. At least one of the edges has a thinned zone in the first direction such that the edges at this thinned zone are separated by a distance in the first direction greater than the distance separating them outside this zone, said thinned zone being located in the immediate vicinity of one of the walls of the body forming an end wall of the body.

[0009] Thus, a characteristic of the invention lies in the production of a thinned zone at at least one of the edges of the insulation in the immediate vicinity of an end wall of the body. This end wall is in particular chosen so as to correspond to a zone where the wires cross during winding. This is generally the smallest end wall of the body, typically located on one side of the body in the second direction. When winding a wire around the insulation, several layers of wire are superimposed and at least one layer change is carried out near the at least one edge having the thinned zone. This additional space makes it possible to deform the wire during winding and thus to ensure sufficient space (in the first direction) between the wire windings of the same layer.Without this space, within a single layer, the first wire windings will push the following wire windings along the first direction, which leads to undesirable crossings and / or changes in wire position. Thus, by providing a larger space to change the layer of wire and deform it during winding, the thinned area allows for better wire placement.

[0010] This form of insulation also allows for a compact winding, without the need to adjust the wire position after winding, and higher winding efficiency because more layers of wire and / or windings can be added. This can increase the efficiency of the magnetic circuit generated by the coil.

[0011] The thinned area may have dimensions that facilitate the deformation of the wire during its winding,

[0012] Thus, advantageously, the insulation can comprise at least one of the following characteristics: - the thinned zone extends from the end wall to an edge of the rim in the second direction, - the thinned zone extends over at least a portion of a width of the end wall measured in the third direction.

[0013] In particular, following the third direction, the thinned area can begin at near, or from, an edge of the rim. This edge may advantageously correspond to the edge through which the wire is intended to arrive when it is wound. This makes it easier to deform the wire during winding.

[0014] Advantageously, the thinned zone may begin near, or from, this edge, with a progressive increase in the thinning. In particular, the thinned zone may comprise, in the third direction, a first part with a progressive increase in the thinning, a second central part of constant maximum thinning and a third part with a progressive reduction in the thinning. This may make it easier to wind the wire.

[0015] Advantageously, a portion of the end wall of the body may be hollowed out over at least part of its dimension in the first direction, this recess having a first edge and a second edge each extending in the first direction, the first edge being further away in the second direction from a median plane of the body than the second edge, this median plane of the body being parallel to the first direction and to the third direction. The recess is thus asymmetrical with respect to a median plane of the end wall which is parallel to the first direction and to the second direction. Advantageously, the first edge of the recess is located on the side of the end wall through which the wire is intended to arrive when it is wound. Thus, it is easier to guide the wire during winding and this asymmetry will also prevent the wire from slipping or being wound in the wrong place.

[0016] Advantageously, the recessed portion may extend in the third direction over a distance equal to at least three times the diameter of the wire intended to be wound around the insulation. This may facilitate positioning of the wire.

[0017] Advantageously, the body may have grooves intended to receive the wire, each groove extending from a first end to a second end, these ends being located at the end wall of the body and being separated from each other in the third direction, the body having one or more of the following characteristics: - at least one groove has at least one end inclined towards one of the edges in the first direction, - at least one groove is inclined towards one of the edges following the first direction from its first end to its second end, - at least one groove extends in a single plane perpendicular to the first direction.

[0018] These different arrangements of the grooves make it easier to wind the wire onto the body.

[0019] The invention further relates to a stator or rotor tooth winding comprising a coil insulator as previously described, and at least three layers of conductive wire windings around the body of the insulator, the windings of one layer crossing the windings of an adjacent layer at the end wall. In particular, the winding is carried out along a winding axis parallel to the first direction.

[0020] The invention also relates to a stator or rotor tooth comprising a tooth body and a coil insulator or winding as described above, the envelope of the coil insulator surrounding and conforming to the tooth body.

[0021] The invention finally relates to a rotating electrical machine comprising at least one stator or at least one rotor provided with a plurality of teeth as described above. The rotating electrical machine may be a radial flux or axial flux electrical machine, advantageously an axial flux machine. Advantageously, the at least one stator is provided with a plurality of teeth according to the invention.

[0022] Another object of the invention is a method of winding a wire onto a coil insulator according to the invention comprising the following steps: (a) a first layer of windings is formed on the body of the insulator in the following manner: (i) the wire is wound along the body of the coil insulator from a first edge corresponding to one of the edges of the body, to the second edge, corresponding to a thinned edge having a thinned area, (ii) at each end of a winding turn, located at the end wall of the body, the wire is guided to an adjacent position, and (iii) when winding the last turns close to the thinned edge, at the end of each winding turn, at the end wall of the coil insulation, the wire is stretched towards the thinned area of ​​the second edge to deform it, (b) at the end of the last turn of winding of the first layer, the wire is positioned between two adjacent windings of the wire of the first layer or between the last winding of the first layer and the second adjacent flange, (c) a second layer of winding is formed on the body of the insulator in the following manner: (i) the wire is continued to be wound on the previous layer of windings by positioning the wire between two adjacent windings of the previous layer up to the first edge, (ii) at each end of a winding turn, located at the end wall of the body, the wire is guided to an adjacent position, the windings of the second layer crossing the windings of the previous layer at this end wall, (iii) optionally, the first edge also has a thinned area and, when winding the last turns close to the first thinned edge, at the end of each winding turn, the wire is stretched towards the thinned area of ​​the first edge to deform it, (d) at the end of the last winding turn of this second layer, the wire is positioned between two adjacent windings of the previous layer or between the last winding of the second layer and the first adjacent edge, (e) a third layer of windings is formed on the body of the insulator in the following manner: (i) the wire is continued to be wound on the previous winding layer up to the second edge to form a third winding layer, (ii) at each end of a winding turn, located at the end wall of the body, the wire is guided to an adjacent position, the windings of the third layer crossing the windings of the previous layer at this end wall. When it is desired to produce a winding comprising more than three layers of windings, step (e) may then comprise: (iii) when winding the last turns close to the thinned edge, at the end of each winding turn, at the end wall of the coil insulator, the wire is stretched towards the thinned zone of the second edge to deform it, and, at the end of the last winding turn of this third layer, then, (iv) the wire is positioned between two adjacent windings of the previous layer or between the last winding of the previous layer and the second adjacent edge, and step c) or steps c) to e) are repeated once or steps c) to e) several times. This thus makes it possible to obtain a winding with 3, 4 or more layers of windings. Step a) may be preceded by an optional step in which the coil insulation is positioned around a stator or rotor tooth.

[0023] Other features and advantages of the invention will emerge from reading the description given below of several particular embodiments of the invention, given for informational purposes but not as a limitation, with reference to the appended drawings in which:

[0024] [Fig. 1] is a schematic radial sectional view of a rotor or stator of a rotating electrical machine.

[0025] [Fig. 2] is a schematic perspective view of a winding according to one embodiment of the invention.

[0026] [Fig. 3] is a schematic perspective view of a coil insulator according to one embodiment of the invention, mounted on a tooth and before winding of an electrically conductive wire.

[0027] [Fig. 4] is a sectional view in a plane perpendicular to the first direction of a coil insulator according to an embodiment of the invention.

[0028] [Fig. 5] is a schematic side view along the second direction of a winding according to one embodiment of the invention.

[0029] [Fig. 6] is a schematic side view in the second direction of a winding according to another embodiment of the invention.

[0030] [Fig. 7] is a partial schematic perspective view of a tooth and the windings of a conductive wire according to a first embodiment of the invention.

[0031] [Fig. 8] is a partial schematic perspective view of a tooth and windings of a conductive wire according to a second embodiment of the invention.

[0032] [Fig. 9] is a partial schematic perspective view of a tooth and windings of a conductive wire according to a third embodiment of the invention.

[0033] [Fig. 10] is a partial schematic perspective view of a tooth and windings of a conductive wire according to a fourth embodiment of the invention.

[0034] Figure 1 shows a rotor or stator 1 of a radial flux rotating electrical machine. The rotor or stator 1 comprises a plurality of teeth 3 which extend radially relative to an axis 2.

[0035] The stator or rotor tooth 3 here comprises a tooth body 4 on which a tooth winding is installed (not shown for greater clarity in figure 1).

[0036] The tooth body 4 is made of a magnetically conductive alloy or a metallic material such as electrical steel or a soft magnetic composite, typically it is made from a stack of metal sheets. The tooth body 4 typically has a right prism shape with an isosceles trapezoidal base.

[0037] With reference to Figure 2, the tooth winding 5, for its part, comprises a coil insulator 6 and generally several layers of windings 7 of a conductive wire surrounding the insulator 6, a single layer of winding 7 being shown in Figure 2. The wire used consists of an electrically conductive wire, for example a copper or aluminum wire, the wire can be of circular, rectangular section or have a flat. The coil insulator 6, for its part, forms an envelope surrounding and fitting the tooth body (not shown in Figure 2), it is made of an electrically insulating material, for example a moldable material, such as a polymer material and / or paper.

[0038] The insulator 6 can be installed on the body of the tooth in several ways, it can be overmolded on the tooth body or be made separately and subsequently fitted onto the tooth body. The windings 7 of the wire around the insulator 6 can be made while the insulator is installed around the tooth, which can make it possible to maintain the insulator on the tooth, or before the installation of the insulator 6 around the tooth. In the example shown in Figure 2, the tooth winding 5 is made before the mounting of the insulator 6 on the tooth. In other words, the windings 7 are made while the insulator 6 is not installed on the body of the tooth. On the contrary, in the example shown in Figure 3, the insulator 6 is first mounted on the tooth body 4, then the winding of the wire around the insulator is carried out.

[0039] When the insulator is made separately and fitted onto the tooth body, it can be made in a single piece (as shown in Figure 3) or in several pieces made independently (as shown in Figure 2). The insulator 6 can be made of two or more pieces of polymer material insulator or, as shown in Figure 2, of two pieces 6a, 6b of polymer material insulator and two pieces 6c, 6d of insulating paper. The different pieces are then assembled either by friction thanks to the fitting of the insulator onto the tooth body, or by a male-female connection between the pieces, or by adhesive tape or by gluing, or simply held on the tooth by the windings.

[0040] As shown in Figures 2 and 3, the coil insulator 6 comprises a body 8 comprising walls 9 (four in the example, designated by the references 9a-9d in Figure 2) extending in a first direction DI and forming the envelope intended to surround the stator or rotor tooth body and which matches its shape.

[0041] The body 8 further has, in a plane perpendicular to the first direction D1, a length extending in a second direction D2 and a width extending in a third direction D3, the second D2 and third D3 directions being perpendicular to each other. As can be seen more clearly in Figure 2, the body here has the shape of a right prism with an isosceles trapezoidal base. In the example, it thus comprises four walls, two side walls 9a, 9b and two end walls 9c and 9d. The end wall 9d here being of smaller dimensions than the other end wall 9c in the direction D2. This end wall 9d is usually located on the side of axis 2 of the stator or rotor, the second direction D2 then extending radially relative to axis of the stator or rotor, the first direction D1 extending axially.

[0042] The insulator 6 also has a first rim 10 and a second rim 11 extending from opposite edges of the walls 9 (in the direction D1) and defining with them a groove 13 (see fig. 3) intended to receive the winding of a wire. These rims extend perpendicularly or substantially perpendicularly to the first direction. By "substantially perpendicularly" is meant that these rims may have areas not perpendicular to the first direction, such as for example the parts 10a, 10b described below used to retain the wire ends.

[0043] The insulator 6 thus has a general shape of a coil with an axis in the first direction DL. The winding of the wire around the body 8 of the insulator 6 is then carried out in at least three layers, by rotation around a winding axis which is parallel to the first direction Dl, the change of layer occurring at the level of the first rim 10 or the second rim 11 and in the immediate vicinity of the end wall 9d of the body 8. Thus, the windings of two superimposed layers cross at the level of this end wall 9d, as can be seen. see it in figures 5 to 10.

[0044] Usually, the insulator 6 also comprises, on the side of one of the edges, here the edge 10, zones 10a, 10b serving to guide and hold the ends of the wire (see fig. 3 and 5-6).

[0045] As seen in Figure 3, the walls 9 also have grooves 14 intended to accommodate the wire during its winding. Each groove 14 extends from a first end 14a to a second end 14b, these ends 14a, 14b of the grooves being located at the end wall 9d of the body and being separated from each other along the third direction D3. This interruption of the grooves at the end wall 9d will facilitate the crossing of the wires of the superimposed winding layers.

[0046] Figure 3 illustrates grooves 14 which are parallel to the second direction D2, each groove extending in a single plane perpendicular to the first direction D1. However, one or more grooves may also be gradually curved or inclined upwards towards the first rim 10 in the first direction D1 or downwards towards the second rim 11 in the first direction D1, this inclination then being progressive from their first end to their second end, or one or more grooves may have at least one end inclined towards one of the rims in the first direction. These different groove shapes may make it possible to increase the space available for the crossing of the wire at the end wall and / or to follow the desired winding shape of the wire.Examples of wire winding shapes that can be obtained are described below with reference to Figures 7 to 10. Thus, grooves can be chosen so that they follow or not the desired shape of the windings.

[0047] In the embodiment shown in Figure 3, the second rim 11 has a thinned zone 15 along the first direction D1 so that at this thinned zone 15, the first 10 and second 11 rims are separated by a distance (along D1) greater than the distance separating them outside this zone. Along the first direction D1, the second rim 11 therefore has a certain thickness which will decrease in the thinned zone 15. It will be possible to envisage a minimum thickness of the thinned zone representing 10% of the thickness of the rim outside this thinned zone.

[0048] The thinned zone 15 is located in the immediate vicinity of the end wall 9d of the body 8, it preferably extends from the end wall 9d to an edge 11a of the second rim 11 along the second direction D2. The thinned zone 15 also extends over at least a portion of a width of the end wall 9d measured along the third direction D3. This width may advantageously be chosen to facilitate deformation of the wire during its winding. For example, the width of the thinned zone may correspond to 50% of the total width of the rim 11, in particular at the end wall 9d.

[0049] Preferably, along the third direction D3, the thinned zone 15 starts from an edge 11b of the second rim 11 as shown in FIG. 6, or close to this edge 11b as shown in FIG. 5, this edge 11b being located on the side by which the wire arrives at the end wall 9d during its winding. In particular, a progressive increase in the thinning may be achieved. In the example of FIG. 6, the thinned zone 15 comprises, along the third direction D3, three parts: two end parts which have a progressive increase in the thinning towards a central part, of constant thinning. This central part may be symmetrical with respect to a median plane of the body parallel to the directions DI and D2 or not. In the example of FIG. 5, these end parts are very short along the direction D3, in favor of a wider central part of constant thinning.

[0050] Depending on the case, the thinned zone can be produced at the first edge 10 in the same way as described previously with reference to edge 11. It will thus be possible to provide for producing the thinned zone at each edge or at one of the two edges only. In the latter case, the thinned zone can advantageously be produced at an edge on the side where winding does not begin (namely edge 11 in the examples). The choice of placing the thinned zone at the first edge and / or the second edge is made according to the number of windings (turns) of a wire from one layer to the other. For example, the thinned zone is placed at the second edge in the case where there is the same number of wires wound in each layer, the winding beginning on the side of the first edge. Examples will be detailed below with reference to FIG. 10.

[0051] The coil insulator 6 finally comprises a hollowed-out portion 17 at the end wall 9d of the body 8 of the insulator over at least part of the dimension of this body 8 in the first direction DI. The end wall 9d is thus hollowed out in the direction D2 towards the center of the body of the insulator. This hollowed-out portion 17 has a first edge 17a and a second edge 17b each extending in the first direction D1, in particular parallel thereto. The hollowed-out portion 17 further has two other edges 17c, 17d connecting the first two edges, as seen in FIG. 3.

[0052] According to the invention, and as seen more clearly in Figure 4, the first edge 17a is further away in the second direction D2 from a median plane Pm of the body than the second edge 17b, this median plane Pm of the body being parallel to the first direction D1 and to the third direction D3. Thus, the distance d1 between the edge 17a and the plane Pm is greater than the distance d2 between the edge 17b and the plane Pm, as shown in Figure 4. In fact, the hollowed-out part 17 has an asymmetry with respect to a median plane of the end wall 9d which contains the first direction DI and the second direction D2. The hollowed-out portion 17 thus has an empty area 18, represented by hatching in Figure 4, which can be of any shape regardless of the type of winding, provided that the edge 17a is further from the plane Pm than the edge 17b. For example, generally speaking, the difference between the distances dl and d2 can represent at least 1 / 10 emethe diameter of the wires used for winding.

[0053] Along the direction D3, the hollowed-out portion 17 has a width delimited by a first end wall 19 and a second end wall 20, these walls being able to be parallel to the plane (D1, D2) or not.

[0054] Preferably, for better crossing of the windings of two superimposed layers, the distance d3 along the direction D3 separating the edges 17a and 17b may be at least three times the diameter of the wire used for the winding.

[0055] Once the insulation has been made, whether it is already installed on the tooth or not, the wire can be wound onto the insulation using the winding process described below.

[0056] So, depending on the case, the coil insulation can be positioned on a stator or rotor tooth. For example, if the insulation is made of several pieces and is held by friction, then it must be positioned on the tooth before winding the wire. However, the winding can also be done before the insulation is positioned on the tooth.

[0057] Then, as seen more clearly in Figure 5 or 6, the conductive wire 21 is wound along the body 8 of the coil insulator 6 from a first edge 10 corresponding to one of the edges, to the second edge 11, corresponding to the edge having a thinned zone 15 to form a first layer of windings. One end 21a of the wire is thus generally held at the guide zone 10b of the first edge 10 before the start of winding. Then, the wire 21 is wound around the body 8 along a winding axis corresponding to the first direction D1.

[0058] For this first layer of windings, the wire is guided in the grooves 14 of the walls 9. As the winding progresses, the wire will thus change height in the first direction D1 and form windings 7 of wire, adjacent to each other. The change in height is achieved at the end wall 9d, and in particular at the hollowed-out portion 17 when it is present. In this case, the wire 21 is then wound from the edge 17a of the hollowed-out portion 17 to the edge 17b of the hollowed-out portion 17. Since the edge 17a is further from the median plane Pm of the body than the edge 17b in the direction D2, it is easier to guide the wire from one groove to the adjacent groove.

[0059] Then, as one approaches the second rim 11, during the winding of the last turns close to the thinned rim 11, at the end of each winding turn, at the end wall 9d of the coil insulator 6, the wire 21 is stretched towards the thinned area 15 of the second rim 11 to deform it. It is the thinning of the edge 11 which allows this stretching and the resulting deformation of the wire.

[0060] At the end of the last winding turn of the first layer, the wire 21 is positioned between two last adjacent windings 7 of the wire of the first layer or between the last winding of the first layer and the rim 11. The fact of being able to deform the wire 21 by pulling it towards the thinned zone facilitates this positioning. In addition, when this stretching is carried out during the winding of the last turns close to the thinned rim 11, this makes it possible to separate the wires from each other and thus to facilitate the positioning of the wire between the windings of the first layer during the production of the second layer, thus reducing the pressures exerted by the windings of the second layer closest to the rim 11 on the windings of the second layer closest to the first rim 10 in the direction D1. This makes it possible to limit these pressures and the displacements of the wire that they can generate.The spacing of the windings can also promote the circulation of a cooling fluid between the windings and thus improve the power supplied by the machine.

[0061] Depending on the width of the thinned zone 15 in the direction D3, the wire 21 is stretched, and therefore deformed, over a greater or lesser length, which will leave more or less space for the following winding 7 of the wire.

[0062] To produce this first layer, the wire follows the grooves 14: it will thus be possible to produce grooves which follow a path corresponding to the desired path of the winding, with for example at least one groove which has a first end lower than its second end in the direction D1 with a continuous inclination from one end to the other, and / or an inclination of at least one groove only at one or both of its ends, for example at the level of the end wall and / or at least one groove which extends in a single plane perpendicular to the first direction DL. In particular, depending on the shape of the desired winding, one or more of the grooves previously described may be provided. Alternatively, each groove could extend in a single plane perpendicular to the first direction DL.

[0063] The winding 7 of the wire 21 then continues onto the first winding layer by positioning the wire between two adjacent windings of the first layer up to the first flange 10 to form a second winding layer, the windings of the second layer crossing the windings of the first layer at the end wall 9d.

[0064] Optionally, if the first edge 10 has a thinned area, when winding the last turns close to the first thinned edge, at the end of each winding turn, then the wire 21 is stretched towards this thinned area of ​​the first edge 10 to deform it. Then, at the end of the last winding turn of this second layer, the wire 21 is positioned between two adjacent windings of the second layer or between the last winding of the second layer and the flange 10. This allows the windings to be spread apart to facilitate the placement of the next layer, as described above.

[0065] Once the third layer is started, the wire 21 is wound onto the second layer of windings, the wire being positioned between the windings of the previous layer, up to the second flange 11 to form a third layer of windings, the windings of the third layer crossing the windings of the second layer at the end wall 9d.

[0066] If one wishes to add additional layers, one can then repeat the steps previously described, a fourth layer can be made in a similar way to the second layer, a fifth layer can be made in a similar way to the third layer, etc.

[0067] The deformations applied to the wire are visible in Figures 5 and 6. Examples of the shape of windings that can be produced are described with reference to Figures 7 to 10.

[0068] Figure 7 shows a tooth 3 comprising three layers of windings of the wire 21. For the sake of clarity, the insulation is not shown. Outside the crossing zone (corresponding to the end wall 9d of the insulation), each winding extends in the same plane perpendicular to the first direction DI.

[0069] The embodiment of Figure 8 differs from that of Figure 7 only in that the wire 21, when leaving the crossing zone and arriving at the crossing zone, is, in particular for the windings closest to the upper edge of the tooth in the direction DI (corresponding to the edge 11 of the insulator), deformed in the same direction in the first direction D1, here upwards, towards the thinned edge of the insulator (not shown), this inclination being located near the crossing zone, therefore near the end wall 9d of the insulator. The remainder of each winding thus also extends in the same plane perpendicular to the first direction DL

[0070] The embodiment of Figure 9 differs from that of Figure 7 in that the wire 21, when leaving the crossing zone and arriving at the crossing zone, is, in particular for the windings closest to the upper edge of the tooth in the direction D1 (corresponding to the edge 11 of the insulator), inclined in the same direction in the first direction D1, here upwards, towards the thinned edge of the insulator (not shown), this inclination being achieved progressively along the sides of the tooth (corresponding to the side walls 9a and 9b of the insulator) from a rear part 22 of the winding located on the side of the tooth close to the end wall 9c of the insulator, to a front part 23 of the tooth close to the end wall 9d of the insulator, or even at the rear, at the end wall 9c of the insulator.This makes it possible in particular to separate the adjacent windings from each other in the first direction D1, as shown in figure 9.

[0071] Figure 10 shows embodiments having more than three layers of wire windings 21. In Figure 10, a tooth 3 is shown on which 4 layers of windings of a wire 21 have been arranged (the insulation is not shown). For the sake of simplification, only the rear 22 and front 23 parts of the windings are shown. The letters (a), (b), (c), (d), (e) and (f) in Figure 10 designate different possibilities of winding the wire from one layer to the next. In each of the cases (a) to (f), each winding of the second, third and fourth layers is arranged between two windings of the previous layer or between the last winding of the previous layer and the nearest edge. The arrows shown indicate which layer changes require stretching and deforming the wire to facilitate positioning of the wire on the next layer.The winding of the first layer also begins on the lower side of the tooth, namely on the side of the first edge 10 of the insulation.

[0072] In case (a), each layer has the same number of windings. An upward stretching of the wire in the direction DI (towards the second edge 11 of the insulation) is here carried out when passing from the first layer to the second layer and from the third layer to the fourth layer. A downward stretching of the wire in the direction DI (towards the first edge 10 of the insulation) is also carried out when passing from the second layer to the third layer.

[0073] In case (b), the second and fourth layers have an additional winding compared to the number of windings of the first and third layers. An upward stretching of the wire in the direction DI (towards the second edge 11 of the insulation) is carried out here when passing from the first layer to the second layer and from the third layer to the fourth layer. On the other hand, it is not necessary to stretch the wire downwards in the direction DI (towards the first edge 10 of the insulation).

[0074] In case (e), the second layer has one additional winding compared to the number of windings of the first layer, the third layer has the same number of windings as the second layer and the fourth layer has one additional winding compared to the number of windings of the third layer. The additional windings are each added on the upper side of the tooth, namely on the side of the second edge 11 of the insulator. An upward stretching of the wire in the direction DI (towards the second edge 11 of the insulator) is carried out here when passing from the first layer to the second layer and from the third layer to the fourth layer. On the other hand, it is not necessary to stretch the wire downwards in the direction DI (towards the first edge 10 of the insulator).

[0075] In case (d), the first and third layers have the same number of windings and the second layer has an additional winding. A stretching of the wire upwards in the direction DI (towards the second edge 11 of the insulation) is here carried out when passing from the first layer to the second layer. On the other hand, it is not necessary to stretch the wire downwards in the direction DI (towards the first edge 10 of the insulation).

[0076] In case (e), six layers of windings are present, the first, third and fifth layers having the same number of windings, the second, fourth and sixth layers having the same number of windings comprising one more winding than the lower layers. An upward stretching of the wire in the direction DI (towards the second edge 11 of the insulation) is here carried out when passing from the first layer to the second layer, from the third layer to the fourth layer and from the fifth to the sixth layer. On the other hand, it is not necessary to stretch the wire downwards in the direction DI (towards the first edge 10 of the insulation).

[0077] In case (f), five layers of windings are present, all comprising the same number of windings. An upward stretching of the wire in the direction DI (towards the second edge 11 of the insulation) is here carried out when passing from the first layer to the second layer and from the third layer to the fourth layer. A downward stretching of the wire in the direction DI (towards the first edge 10 of the insulation) is also carried out when passing from the second layer to the third layer and from the fourth layer to the fifth layer.

[0078] In cases (a) and (f), thinning will thus preferably be carried out at both the first edge 10 and the second edge 11 of the insulation to allow the wire to stretch and deform upwards and downwards. In cases (b), (c), (d) and (e), thinning will preferably be carried out only at the second edge 11 of the insulation to allow these upward stretches and deformations of the wire. In all cases, the wire may be stretched only during the last winding of a layer when moving to the next layer, or also during several of the previous windings.

[0079] We thus understand that thinning a rim allows adding a winding on the side of this rim.

[0080] It is thus possible to combine the different embodiments described in order to produce windings with three or more layers of windings in a simple and stable manner depending on the number of windings in each layer.

[0081] The invention thus makes it possible to produce a compact winding, without having to modify the position of the windings at the end of the manufacturing process. It can also make it possible to produce a winding which, although compact, has spacings between the windings promoting their cooling and consequently a high continuous power supplied. The invention can also make it possible to increase the quantity of wound conductive wire by increasing the number of windings of one or more of the layers, improving the efficiency of the winding. When the recess is present, it also makes it possible to reduce the dimension of the winding in the direction D2 at the crossings of the windings, which makes it possible to increase the maximum power density provided by the winding. Finally, by facilitating the positioning of the wires at each winding of the wires, the invention makes it possible to reduce the manufacturing time of a winding.

Claims

Claims

1. Coil insulator (6) intended to be positioned around a tooth (3) of a stator or rotor (1) of an electrical machine, this coil insulator (6) comprising: - a body (8) comprising walls (9) extending in a first direction (D1) and forming an envelope intended to surround a tooth (3) of a stator or rotor (1), as well as a first rim (10) and a second rim (11) extending perpendicularly or substantially perpendicularly to the first direction (D1) from opposite edges of the walls (9) and defining with them a groove (13) intended to receive the windings (7) of a coil, the body (8) having in a plane perpendicular to the first direction (D1), a length extending in a second direction (D2) and a width extending in a third direction (D3), the second (D2) and third (D3) directions being perpendicular to each other, characterized in that at least one of the rims (10,11) has a thinned zone (15) along the first direction (Dl) such that the edges at the level of this thinned zone (15) are separated by a distance along the first direction (Dl) greater than the distance separating them outside this zone, said thinned zone (15) being located in the immediate vicinity of one of the walls of the body (8) forming an end wall (9d) of the body (8).,

2. Coil insulator (6) according to claim 1, characterized in that it comprises at least one of the following characteristics: - the thinned zone (15) extends from the end wall (9d) to an edge (11a) of the rim (11) in the second direction (D2), - the thinned zone (15) extends over at least part of a width of the end wall (9d) measured in the third direction (D3).

3. Coil insulator (6) according to claim 1 or 2, characterized in that, in the third direction (D3), the thinned zone (15) starts near, or from, an edge (11b) of the flange, optionally with a progressive increase in thinning from this edge.

4. Coil insulator (6) according to any one of claims 1 to 3, characterized in that a part of the end wall (9d) of the body (8) is recessed over at least part of its dimension in the first direction (Dl), this recess having a first edge (17a) and a second edge (17b) each extending in the first direction (Dl), the first edge (Dl) being further away in the second direction (D2) from a median plane (Pm) of the body than the second edge (17b), this median plane of the body being parallel to the first direction (Dl) and to the third direction (D3).

5. Coil insulator (6) according to claim 4, characterized in that the recessed portion (17) extends in the third direction over a distance equal to at least three times the diameter of the wire intended to be wound around the insulator.

6. Coil insulator (6) according to any one of claims 1 to 5, characterized in that the body (8) has grooves (14) intended to receive the wire, each groove (14) extending from a first end (14a) to a second end (14b), these ends (14a, 14b) being located at the end wall (9a) of the body and being separated from each other in the third direction (D3), the body having one or more of the following characteristics: - at least one groove has at least one end inclined towards one of the edges in the first direction, - at least one groove is inclined towards one of the edges following the first direction from its first end to its second end, - at least one groove extends in a single plane perpendicular to the first direction.

7. A stator or rotor (1) tooth winding (5) comprising a coil insulator (6) according to any one of claims 1 to 6, and at least three layers of windings of conductive wire(s) (21) around the body (8) of the insulator (6), the windings (7) of one layer crossing the windings (7) of an adjacent layer at the end wall (9d).

8. Tooth (3) of stator or rotor (1) comprising a tooth body (4) and a coil insulator (6) according to any one of claims 1 to 6 or a winding according to claim 7, the envelope of the coil insulator (6) surrounding and conforming to the tooth body (4).

9. Rotating electrical machine comprising at least one stator or at least one rotor (1) provided with a plurality of teeth (3) according to claim 8.

10. A method of winding a wire (21) onto a coil insulator (5) according to any one of claims 1 to 6, comprising the following steps: - optionally, the coil insulator (6) is positioned around a tooth (3) of the stator or rotor (1), (a) a first layer of windings is formed on the body of the insulator in the following manner: (i) the wire (21) is wound along the body (8) of the coil insulator (6) from a first edge (10) corresponding to one of the edges of the body, to the second edge (11), corresponding to a thinned edge having a thinned zone (15), (ii) at each end of a winding turn, located at the end wall of the body, the wire is guided to an adjacent position, and, (iii) when winding the last turns close to the thinned edge, at the end of each winding turn, at the end wall (9d) of the coil insulator (6), the wire (21) is stretched towards the thinned area (15) of the second edge (11) to deform it, (b) at the end of the last winding turn of the first layer, the wire (21) is positioned between two adjacent windings (7) of the wire of the first layer or between the last winding of the first layer and the second adjacent edge (11), (c) a second layer of winding is formed on the body of the insulator in the following manner: (i) the wire (21) is continued to be wound on the previous layer of windings by positioning the wire between two adjacent windings of the previous layer up to the first edge (10), (ii) at each end of a winding turn, located at the end wall of the body, the wire is guided to an adjacent position, the windings of the second layer crossing the windings of the previous layer at this end wall (9d), (iii) optionally, the first rim (10) also has a thinned zone (15) and, when winding the last turns close to the first thinned rim, at the end of each winding turn, the wire (21) is stretched towards the thinned zone (15) of the first rim (10) to deform it, (d) at the end of the last winding turn of this second layer, the wire (21) is positioned between two adjacent windings (7) of the previous layer or between the last winding of the second layer and the first adjacent edge (10), (e) a third layer of windings is formed on the body of the insulator in the following manner: (i) the wire (21) is continued to be wound onto the winding layer previous to the second edge to form a third layer of winding, (ii) at each end of a winding turn, located at the end wall of the body, the wire is guided to an adjacent position, the windings of the third layer crossing the windings of the previous layer at the end wall (9d), (iii) optionally, when winding the last turns close to the second thinned edge, at the end of each winding turn, at the end wall of the coil insulation, the wire is stretched towards the thinned area of ​​the second edge to deform it, and, at the end of the last winding turn of this third layer, then (iv) the wire is positioned between two adjacent windings of the previous layer or between the last winding of the previous layer and the second adjacent edge (11) and step c) or steps c) to e) or steps c) to e) are repeated once or several times.

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