Stator for rotating electric machine

Abstract

The invention relates to a method for manufacturing a stator (2) for an electric machine, the method comprising: a toothed ring (25) comprising teeth (23) connected together by material bridges (27) and recesses (21) defined between the teeth, the recesses (21) being radially open towards the outside; a winding (22) produced outside the recesses (21); and a yoke (29) configured to be attached to the toothed ring (25), the method comprising the steps of: fastening at least one sheet-like insulating member to at least one portion (22a, 22b) of each winding in the winding; inserting the winding portion (22a, 22b) with the insulating member into the recess (21) by a radial movement directed towards the inside of the recess (21); and assembling the yoke (29) onto the radial outer surface of the ring (25) so as to radially close the recess (21).

Description

[0001] The present invention relates to rotating electrical machines and more particularly to stators for such electrical machines. The invention also relates to methods for manufacturing these electrical machines.

[0002] In most known stators, the yoke forms a fully open or half-open slot towards the air gap to allow the winding to be inserted. Typically, the half-open slots receive loosely placed electrical conductors of circular cross-section, while the open slots accommodate electrical conductors of rectangular cross-section placed in an ordered manner. In both cases, the electrical conductors are insulated from the stator block by a sheet of material inserted into the U-shaped slot and receiving the electrical conductors. In the case where the slot receives two windings with different phases, the windings with different phases are also separated from each other by sheet-like insulating pieces. When inserting the electrical conductors, it is necessary to keep one or more sheet-like insulating pieces in place in the slots.

[0003] Patent US 6 198 190 describes a stator having a slot which is half-open towards the air gap for receiving a U-shaped electrical conductor of rectangular cross section. Such an electrical conductor is inserted into the slot by sliding it into the slot along its longitudinal axis. The electrical conductor is insulated from the stator block and from each other by an S-shaped insulating piece placed in the slot. The insulating piece is inserted into the slot before the electrical conductor is inserted.

[0004] Patent application FR 3 019 947 describes a stator comprising a toothed ring comprising teeth connected to each other by material bridges and slots defined between the teeth for receiving coils, said slots being open radially towards the outside. The openings of the slots are closed by a yoke attached to the toothed ring.

[0005] There is a need for a method for manufacturing a stator for a rotating electrical machine which allows easy and efficient filling of the slots while providing satisfactory electromagnetic performance.

[0006] The invention more particularly seeks to insulate the winding in the notch while limiting as much as possible the risks of damage to the insulation and at the same time allowing a quick and easy placement of the winding in the notch.

[0007] method

[0008] According to a first aspect, the present invention solves this need by means of a method for manufacturing a stator of an electric machine, the method comprising:

[0009] a toothed ring comprising teeth joined together by material bridges and notches defined between the teeth, said notches being open radially towards the outside;

[0010] - windings produced outside the notches; and

[0011] - a yoke configured to be attached to the ring,

[0012] The method comprises the following steps:

[0013] Attaching at least one sheet insulation to at least a portion of each of the windings;

[0014] inserting the winding part with the sheet-like insulation into the slot by a radial movement directed towards the interior of the slot; and

[0015] • Assemble the yoke onto the ring to radially close the notch.

[0016] The yoke is in particular able to hold the winding in the notch after the winding has been inserted.The yoke can be assembled with the ring in various ways.

[0017] The fact that the slots are radially open towards the outside allows the windings to be inserted into the slots by a radial movement towards the inside of the slots. This makes the installation of the windings easier, on the one hand because it is easier to access the inside of the slots, which are completely open and facing the outside than the slots facing the air gap, and on the other hand because the space available around the ring for the necessary tools is much larger than the space available in the bore of the stator.

[0018] Fixing the sheet insulation to the winding allows the winding to be insulated from the edge of the slot and mechanically holds the conductor of the winding while the stator is being manufactured. This holding makes it easier to insert the winding into the slot and reduces the space between the turns of the winding.

[0019] In particular, the fact that the slot is open towards the outside makes it possible to insert the winding with the insulation into the slot, thereby increasing the space available for the insertion of the winding. The risk of damaging the insulation is reduced. Furthermore, the step of insulating the winding relative to the surface of the slot is carried out outside the slot, making this step easier and more reliable.

[0020] Finally, such an insulation makes it possible to increase the range of options for arranging the insulation on the winding, since it is no longer necessary for the insulation to be open towards the opening of the slot to allow the insertion of the electrical conductor. This allows a better insulation of the winding.

[0021] The method includes a step of forming a winding before the step of fixing the insulating member.

[0022] The method may comprise the step of applying adhesive to the sheet insulation or to the corresponding winding portion before the step of fixing the sheet insulation to each winding portion, when the sheet insulation is not pre-coated with adhesive.

[0023] In case the winding has a substantially rectangular cross-section, the step of fixing a sheet-like insulation to each of the winding parts may comprise the following sub-steps:

[0024] - Lay the sheet insulation flat;

[0025] - positioning the first face of the winding on the sheet-like insulating member, in particular in the centre of the sheet-like insulating member, by pushing the winding portion into contact with the sheet-like insulating member, in particular by applying pressure to a second face opposite to the first face, in order to maintain contact between the sheet-like insulating member and the first face of the winding;

[0026] - applying the two free sides of the sheet insulation to two opposite sides of the winding;

[0027] - folding a free folded portion of the sheet-like insulating member onto the second surface, and then folding the remaining free folded portion of the sheet-like insulating member onto the second surface, with the end of the sheet-like insulating member overlapping the second surface relative to the width of the corresponding winding; and

[0028] - Apply pressure to the second side of the winding.

[0029] This method of folding ensures that the sheet insulation lies tightly against the winding portion when the winding is inserted into the notch and when the yoke is mounted on the ring, thereby avoiding wrinkles in the sheet insulation on the winding portion and limiting the risk of damaging the sheet insulation.

[0030] The various steps of fixing the insulation can be performed using a suitable folding device, which includes a folding folding wing capable of folding the sheet insulation onto the side, a slide capable of folding the two folded parts of the sheet insulation onto the second face, and a fixing tool capable of holding the winding in place and applying pressure to the second face of the winding. In addition, the presence of the material bridge reduces the risk of losing varnish in the air gap when the finished stator is impregnated with varnish. This can reduce the need for cleaning.

[0031] This can also reduce varnish leakage into the air gap during operation of the electric machine with the stator mounted thereon. This simplifies maintenance of the electric machine.

[0032] The term "lacquer" is to be understood here in a broad sense and includes any type of impregnation material, in particular polymers.

[0033] The stator can be used as a closed impregnation chamber simply by providing seals only at the ends of the stator. This simplifies processing. This also reduces the amount of varnish loss and cleaning operations.

[0034] In addition, the stator greatly reduces the electromagnetic interference associated with the slot opening located on the air gap in the prior art. The opening towards the air gap without the slot can reduce the pulsation of the slot. The electromagnetic performance of the motor is improved.

[0035] stator

[0036] notch

[0037] At least one of the notches, and even better all of the notches, may have opposing edges that are parallel to each other.The width of the notch is preferably substantially constant over the entire height of the notch.

[0038] At least one tooth, and even better all teeth, may be globally trapezoidal in shape when viewed in section in a plane perpendicular to the axis of the stator.

[0039] Preferably, several material bridges each have a deformable area and, preferably, all material bridges each have a deformable area. "Deformable area" refers to the area of ​​the material bridge that is preferably deformed by the relative movement of the teeth connected by the bridge. The deformation of the material bridge may result in an elongation or shortening of the circumferential dimension of the material bridge, which results in an elongation or shortening of the circumferential dimension of the ring. The preferred deformation may be caused by a specific shape provided to the bridge.

[0040] The deformable area makes it possible to adapt the mechanical stresses to which the ring is subjected when it is assembled with the yoke. Furthermore, this makes it possible, if necessary, to have a more open notch before mounting the yoke and thus a greater clearance between the winding and the wall of the notch during insertion of the winding, which makes the insertion of the winding easier and reduces the risk of the insulation being damaged.

[0041] Preferably, the material bridges each have a region of reduced magnetic permeability, in particular in the form of at least one local restriction, at least one local extrusion, at least one opening or at least one local treatment. When the motor is running, the region of reduced magnetic permeability of the material bridge becomes magnetically saturated, thereby limiting the passage of flux and increasing the efficiency of the motor.

[0042] Preferably, the bottom of the slots each has at least one planar portion against which the winding, preferably a winding of substantially rectangular cross-section, bears. The planar portion or portions are substantially perpendicular to the radial axis of the slot.

[0043] Apart from the recess and / or the deformable area, the bottom of the notch may be flat.

[0044] The deformable regions or recesses preferably form a gap between the material bridge and the corresponding winding, which gap facilitates the penetration of the varnish during the impregnation of the stator.

[0045] This allows, in the case of a winding of rectangular cross-section, a good filling of the slot by the winding by allowing the winding to rest flat in the bottom of the slot.

[0046] Yoke-ring joint

[0047] Preferably, during the step of assembling the yoke onto the ring, the ring has a protrusion on its radially outer surface that cooperates with a complementary protrusion belonging to the yoke. Such a protrusion allows the ring and the yoke to remain fixed relative to each other by means of complementary shapes. The cooperating protrusions are preferably of the dovetail and mortise type.

[0048] The method may comprise a preliminary step of making the ring comprising winding a strip of sheet metal comprising teeth connected by bridges of material into a spiral, the opposite edges of each notch preferably being substantially parallel to one another when the strip is wound around itself to form the ring.

[0049] In a variant, the strip may be formed of sectors, each sector comprising a number of teeth, the sectors being connected by connections, the sectors being cut by the strip of sheet metal. In particular when the ring is held in compression by a yoke, the connections may be flexible bridges connecting the sectors to each other and / or parts having complementary shapes, for example of the dovetail and mortise type, or complementary protrusions bearing against each other.

[0050] The complementary shapes may be located on the material bridge so that the different segments are assembled at the level of the material bridge. Preferably, the assembly of the complementary shapes of the different segments is done away from the deformable area of ​​the material bridge and / or the area of ​​reduced permeability of the material bridge. This makes assembly easier, in particular in the case of very large electrical machines. For example, a segment has a concave shape that cooperates with a complementary protruding shape belonging to an adjacent segment.

[0051] In a variant, the step of manufacturing the ring may comprise a step of stacking pre-cut magnetic laminations.

[0052] In another variant, the ring may be produced by additive manufacturing, for example by powder sintering.

[0053] The yoke can be produced by directly winding a strip of metal sheet into a spiral, where the width of the yoke permits, possibly or not with the formation of suitable slits in the strip of metal sheet when cutting to facilitate this winding, or by stacking pre-cut magnetic laminations or sheets produced by additive manufacturing, for example by powder sintering.

[0054] Winding

[0055] The windings can be arranged in the slots in a concentrated or distributed manner.

[0056] "Concentrated" means that the windings are each wound around a single tooth.

[0057] “Dispersed” means that at least one of the windings passes through two non-adjacent slots in succession.

[0058] Preferably, in particular when the number of poles of the rotor is less than or equal to 8, the windings are placed in the slots as dispersed windings.

[0059] The windings each comprise at least one electrical conductor, the cross section of which may be circular or, in particular, polygonal with rounded corners, preferably rectangular, without this enumeration being exhaustive.

[0060] When the conductor has a circular cross section, the conductor can be assembled according to a hexagonal winding. When the conductor has a polygonal cross section, the conductor can be assembled in one or more rows oriented radially to form a winding. The optimized assembly can allow a larger number of electrical conductors to be placed in the slots and thus obtain a higher power stator at the same volume.

[0061] The electrical conductors may be randomly placed in the winding. Preferably, the electrical conductors are arranged in the winding. "Arranged" means that the conductors are not randomly placed in the winding, but are placed in the winding in an orderly manner. The conductors are not randomly stacked in the winding, for example, in one or more rows, in particular in one or two rows, preferably in a single row of aligned electrical conductors.

[0062] Preferably, the conductor has a rectangular cross section and the winding is wound on edge. "Edge" refers to the narrow side of the wire of the winding, as opposed to "plane". A winding wound on edge is a winding in which the wire of the winding with a rectangular cross section, in particular a rectangular cross section, including a direction of extension is wound perpendicular to the plane. The wire is thus wound around the axis of the winding perpendicular to the direction of extension of its cross section.

[0063] The electrical conductor is preferably electrically insulated from the outside by an insulating coating, in particular a varnish.

[0064] Preferably, the winding parts inserted into the slot are each separated from the inner surface of the slot by at least one thickness of the corresponding sheet-like insulating member, and more preferably by at least two thicknesses of the corresponding sheet-like insulating member. Such sheet-like insulating members allow better insulation of the winding relative to the slot.

[0065] Preferably, during the step of inserting the winding parts, each slot receives at least two winding parts, in particular at least two winding parts with different phases. Preferably, the two winding parts overlap at least radially in the slot.

[0066] Two winding parts in the same slot can be separated from each other by at least one thickness of the sheet insulation, preferably by at least two thicknesses of the sheet insulation, and more preferably by at least four thicknesses of the sheet insulation. The greater the number of thicknesses of the sheet insulation between two windings in the same slot, the better the insulation effect.

[0067] The winding forms a winding overhang outside the slot.

[0068] The method may include the step of separating two adjacent winding overhangs with different phases by using an additional sheet-like insulator. The additional sheet-like insulator may be fixed between the two winding overhangs to at least a portion of one of the two winding overhangs in the region where the two overhangs overlap.

[0069] Preferably, the winding is neither a U-shaped ("U-leg") nor an I-shaped ("I-leg") winding.

[0070] The method may include the step of twisting (tilting) the stator. Such tilting may help tighten the windings in the slots and reduce slot harmonics.

[0071] Insulation

[0072] The sheet-like insulating member may be made of any electrically insulating material, preferably flexible, in particular of aramid, e.g. Or it can be made of a laminate of aramid and polyester or polyimide, such as NMN Type or NKN Type laminate, or made of mica / polyester.

[0073] Preferably, the sheet-like insulating member extends over the rectilinear winding portion.

[0074] Preferably, the sheet insulation extends only over the rectilinear winding portion, while the curved portion of the winding is free of sheet insulation.

[0075] Preferably, the sheet-like insulating members are fixed to the winding by means of adhesive bonding over at least a part of the surface of the winding, and even better over the entire surface of the winding. The bonding of the sheet-like insulating members may be done using adhesive on all or part of the sheet-like insulating members and / or on all or part of the corresponding winding portion, or using adhesive tape. As an alternative, each sheet-like insulating member is fixed to the winding portion at least at one of the longitudinal ends of the sheet-like insulating member, preferably at both longitudinal ends of the longitudinal ends of the sheet-like insulating member, or directly to the winding, or using, for example, at least one adhesive tape spanning the sheet-like insulating member and the winding portion, by means of adhesive bonding by means of adhesive on the sheet-like insulating member.

[0076] Preferably, each winding portion is covered with a single sheet of insulation.

[0077] In a variant, each winding part is covered with at least two sheet-like insulating pieces which at least partially overlap each other or have contacting edges, in particular two sheet-like insulating pieces which are formed in a U-shape and fixed end to end on the corresponding winding part.

[0078] Preferably, the plurality of sheet-like insulating elements extend over the entire height of the slot after the winding portion has been inserted into the slot.

[0079] Preferably, a plurality of sheet-like insulating members protrude axially from the slot on each side of the slot after insertion.

[0080] In a variant, the height of the insulating member is substantially equal to the height of the slot, so that the insulating member fits tightly in the slot without protruding beyond the slot. This may prove advantageous in the case of low voltage electrical machines.

[0081] The sheet-like insulating member extends over a length greater than or equal to the height of the notch.

[0082] Each sheet-like insulating member may be wound around the corresponding winding portion one or more times. Preferably, the sheet-like insulating member is wound around the corresponding winding portion at least once, and even better at least twice.

[0083] The sheet-like insulating members may each comprise two opposite longitudinal edges extending substantially along the longitudinal axis of the associated winding portion. In this case, the sheet-like insulating members are preferably made of aramid, or a laminate of aramid and polyester or polyimide.

[0084] Preferably, the winding portion has a rectangular cross section, and two opposite longitudinal edges of each sheet-like insulating member extend on the same face of the corresponding winding portion.

[0085] The longitudinal edges of each sheet-like insulating member may be in contact with each other on the face. In this case, the sheet-like insulating member is wound once around the corresponding winding portion.

[0086] In a variant, each sheet-like insulating member may at least partially overlap on itself. In this case, the sheet-like insulating member is wound more than once around the winding portion. Preferably, the insulating member is then coated with adhesive at least on the surface of the insulating member close to at least one of the longitudinal edges.

[0087] Preferably, when the winding has a rectangular cross section, the two longitudinal edges of the sheet-like insulating element extend on the same face of the winding part. The sheet-like insulating element is fixed to the winding part in particular using the method described above. In this case, only the two folded portions folded onto the second face may be coated with adhesive.

[0088] Preferably, each winding portion is placed in the corresponding slot so that the longitudinal edge of the corresponding sheet insulation extends on the following face of the winding portion, which is oriented towards the opening of the slot or towards a part of the winding inserted into the same slot, in particular a part with a different phase.

[0089] Preferably, in the case where each slot receives at least two windings and the insulating member is wound once around the corresponding winding portion, each winding portion is placed in the corresponding slot so that the longitudinal edge of the corresponding sheet-like insulating member extends on the face of the winding portion facing the opening of the slot. Thus, two winding portions with different phases are separated by two thicknesses of the sheet-like insulating member, wherein at least one thickness of the sheet-like insulating member is continuous.

[0090] Preferably, in the case where each notch receives at least two windings and each insulating member is wound more than once around the corresponding winding portion, each winding portion is placed in the corresponding notch so that the longitudinal edge of the corresponding sheet-like insulating member extends on the face of the winding portion oriented towards another winding portion, in particular another winding portion with a different phase. The windings with different phases are then separated by four thicknesses of the insulating member.

[0091] In a variant, in the case where each notch receives at least two windings, the longitudinal edges of each sheet-like insulating member may be spaced apart from each other by a distance shorter than the width of the face overlapping the longitudinal edges, and each winding portion is placed in the corresponding notch so that the longitudinal edge of the corresponding sheet-like insulating member extends on the face of the winding portion oriented towards the opening of the notch. Thus, two winding portions with different phases are separated by two thicknesses of the sheet-like insulating member, wherein at least one thickness of the sheet-like insulating member is continuous.

[0092] In a variant, the sheet-like insulation may take the form of a tape that is wound around the winding portion. In this case, the sheet-like insulation is wound a number of times around the corresponding winding portion. Preferably, the tape overlaps itself from one turn around the winding portion to the next. In this case, the sheet-like insulation is preferably made of mica / polyester.

[0093] stator

[0094] According to a second aspect, a further subject of the invention is a stator comprising:

[0095] - a radially inner ring, the radially inner ring comprising:

[0096] o teeth with notches formed therebetween, the notches being open radially outward, and

[0097] o bridges of material which each connect two adjacent teeth at their base on the air-gap side and define the bottom of the notch between the teeth; and

[0098] - a radially outer yoke attached to the ring;

[0099] - windings placed in the slots, each slot having at least a winding of a first phase and a winding of a second phase different from the first phase, these windings being separated in the slots by at least two thicknesses of one or more sheet-like insulating members, one sheet-like insulating member at least partially surrounding each of these windings.

[0100] Features described above in conjunction with the first aspect of the invention also apply to this second aspect.

[0101] Motor and rotor

[0102] Another subject of the invention is a rotating electrical machine comprising a stator as defined above. The electrical machine may be synchronous or non-synchronous. The electrical machine may be a reluctance electrical machine. The electrical machine may constitute a synchronous motor.

[0103] A rotating electrical machine may include a wound rotor or a permanent magnet rotor. DETAILED DESCRIPTION

[0104] The invention may be better understood by reading the following detailed description of non-limiting example embodiments of the invention and by studying the accompanying drawings, in which:

[0105] Figure 1 is a schematic and fragmentary perspective view of a stator according to the invention, with a yoke partially attached to a ring;

[0106] Figure 2 yes Figure 1A schematic diagram of a cross section of a stator;

[0107] Figure 3 is a schematic perspective view of a ring of a stator with windings;

[0108] Figure 4 yes Figure 3 Detailed view of a cross section;

[0109] Figure 5 Depicted Figure 4 Details;

[0110] FIG. 6A to FIG. 6C Depicted Figure 4 Variations of;

[0111] Figure 7 and Figure 8 depicts a variation in which a sheet-like insulator is secured to a winding portion; and

[0112] Fig. 9 A method for securing an insulation member to a winding section is shown.

[0113] Figures 1 to 5 A stator 2 of a rotating electrical machine is depicted. In the case of a motor, the stator enables the generation of a rotating magnetic field that drives the rotor in rotation, and in the case of an alternator, the rotation of the rotor induces an electromotive force in the windings of the stator.

[0114] The examples shown below are schematic and are not necessarily drawn to scale.

[0115] stator

[0116] The stator 2 comprises windings 22 placed in slots 21 formed between teeth 23 of a toothed ring 25. The slots 21 are closed on the air gap side by material bridges 27, each connecting two consecutive teeth of the ring 25 together and having radial openings 28 towards the outside of the ring 25.

[0117] The stator 2 comprises a yoke 29 attached to the ring 25. The yoke 29 has a recessed protrusion 50 of the mortise type cooperating with a protruding protrusion 52 of the dovetail type belonging to the toothed ring 25 for mounting the yoke 29 on the ring 25.

[0118] In the example described, the notch 21 has radial edges 33 that are parallel to one another and a section of the notch 21 in a plane perpendicular to the axis of rotation X of the electric machine is of substantially rectangular shape.

[0119] The shape of the bottom 35 of the notch is substantially complementary to the shape of the winding 22. Figures 1 to 4In the example of FIG. 4 , the bottom 35 of the slot has two flat portions 30 , which are located on either side of the recess 40 and against which the rectangular winding 22 is supported. The bottom 35 of the slot is connected to the radial edge 33 by a rounded corner 36 .

[0120] As shown, the material bridges 27 may have a constant thickness and may be substantially non-deformable. In a variant not shown, the material bridges 27 each have an area of ​​reduced magnetic permeability, in particular a local restriction, an extrusion of the material, a local treatment or one or more openings, allowing the lamination to become magnetically saturated, thereby limiting the passage of the magnetic flux, and / or the material bridges 27 each have a deformable area, making it possible to vary the circumferential diameter of the ring 25.

[0121] The ring 25 and / or the yoke 29 are each formed by a set of magnetic laminations stacked along the axis X, the laminations being identical and precisely superposed. These laminations may be held together by clamps, rivets, tie rods, welding and / or any other technique. The magnetic laminations are preferably made of magnetic steel.

[0122] The ring 25 and / or yoke 29 may alternatively be formed from one or more strips of sheet metal cut and wound about itself.

[0123] Windings and insulation

[0124] The windings 22 can be placed in the slots 21 in a concentrated or distributed manner, preferably in a distributed manner.

[0125] exist Figure 2 In the example shown, the electrical conductors 34 of the winding 22 are placed in the slots in an orderly arrangement.

[0126] If you can Figure 4 As seen in FIG. 1 , the conductors 34 preferably have a rectangular flat cross section and are radially stacked, for example, in a single row. The conductors 34 are stacked one on top of the other through the plane. The winding 22 is considered to be wound on the edge. The cross section of the winding 22 can be generally rectangular in shape.

[0127] In the example shown, the winding 22 has a single radial row of electrical conductors 34. However, the winding 22 may have a plurality of radial rows of electrical conductors, such as two rows of electrical conductors.

[0128] Each slot 21 is capable of receiving two stacked winding portions 22a and 22b having different phases. The cross-section of each winding 22 may be substantially rectangular in shape.

[0129] exist Figure 4 In the example shown, each slot 21 receives two winding portions 22a and 22b having different phases.

[0130] Each winding portion 22a and 22b intended to engage in the notch 21 is surrounded by a sheet-like insulating member 37a and 37b capable of insulating the winding from the walls 33 and 36 of the notch and of insulating the winding portions 22a and 22b having different phases from each other.

[0131] The winding 22 is formed outside the notch 21, and the winding parts 22a and 22b of the winding 22 for engagement in the notch are surrounded by the sheet-like insulating member 37a or 37b, respectively. The sheet-like insulating member 37a or 37b is coated with an adhesive on at least a part of its surface, and the winding parts 22a and 22b having the sheet-like insulating members 37a and 37b thereon are inserted into the notch 21. This operation is facilitated by the fact that the notch 21 is completely radially open toward the outside.

[0132] Each sheet-like insulating member 37a or 37b extends over the entire height of the winding portion 24a or 24b inserted into the corresponding notch 21. Figure 3 As shown, a sheet-like insulating member 37 a or 37 b may extend axially out of the slot 21 on each side of the ring 25 .

[0133] The sheet-like insulators 37a and 37b may have an adhesive layer on their entire surface so that the sheet-like insulators 37a and 37b may be fixed to the corresponding winding portions 24a and 24b by adhesive bonding. Alternatively, the sheet-like insulators 37a and 37b may be fixed to the winding portions 22a and 22b by any other means.

[0134] The sheet-like insulating members 37a and 37b may be made of aromatic polyamide, for example Or it can be made of a laminate of aramid and polyester or polyimide, such as NMN Type or NKN Type Made of laminated parts.

[0135] like Figure 4 and Figure 5 As shown, each sheet-like insulating member 37a or 37b may be wound twice around the corresponding winding portion 22a or 22b. Therefore, the winding portion 22a or 22b is insulated from the slot 21 by two thicknesses of the corresponding sheet-like insulating member 37a or 37b.

[0136] The longitudinal edges 54a or 54b of the sheet-like insulating member 37a or 37b extend on the same face 60a or 60b of the winding portion 24, in particular on the face 60a or 60b of the winding 22 corresponding to the plane of the electrical conductor 34. The winding portions 22a and 22b are oriented in the slot 21 so that the face 60a faces the face 60b. Thus, the winding portions 22a and 22b with different phases located in the same slot are separated from each other by two thicknesses of the insulating member 37a and two thicknesses of the insulating member 37b, i.e. by four thicknesses of the insulating member.

[0137] like Figure 3 As shown, the winding 22 forms a winding overhang 56 outside the slot.

[0138] The winding overhangs 56 of adjacent windings 22 having different phases have connecting portions 58 without any insulating member.

[0139] Rotor

[0140] Figure 1 The rotor 1 depicted in comprises a central opening 5 for mounting on a shaft and comprises a magnetic rotor block 3 extending axially along the axis of rotation X of the rotor, the rotor block being formed, for example, by a set of magnetic laminations stacked along the axis X, said laminations being, for example, identical and exactly superimposed.

[0141] The rotor 1 comprises, for example, a plurality of permanent magnets 7 placed in housings 8 of a magnetic rotor block 3. As an alternative, the rotor is a wound rotor.

[0142] Stator manufacturing method and motor

[0143] The stator can be obtained using the manufacturing method which will now be described.

[0144] The winding 22 is wound by winding the electrical conductor 34, in particular on the edge. The winding 22 has straight sections 22a and 22b for insertion into the slot 21. These straight sections 24 are surrounded by sheet-like insulating members 37a or 37b, each of which is as described above herein. Each sheet-like insulating member 37a or 37b is fixed to the corresponding winding section 22a or 22b by adhesive bonding or by some other means. Each sheet-like insulating member 37a or 37b provides insulation for the winding relative to a group of laminations and relative to each other.

[0145] use Fig. 9 The method shown can secure the sheet insulation 37a and 37b to the winding sections 22a and 22b:

[0146] A. First, place the sheet-like insulating member 37a flat on the platform of the folding device, which platform is not depicted;

[0147] B. placing the first face 80a of the winding portion 22a to be insulated on the insulating member, applying pressure P on the second face 81 opposite to the first face 80 using a holding tool;

[0148] C. folding and smoothing the two free side portions of the sheet-like insulating member 37a extending on both sides of the winding portion 22a onto the side surfaces 82 and 83 in another way or simultaneously by using the folding wings of the platform of the folding device;

[0149] D. folding the free folded portion of the sheet-like insulating member 37a extending from the surface 82 onto the second surface 81 by using a slide that slides along the second surface 81 starting from the surface 82 or from the folding folding wing of the platform of the folding device;

[0150] E. Folding the free folded portion of the sheet-like insulating member 37a extending from the face 83 onto the portion of the sheet-like insulating member folded onto the second face 81 in step D. This step is performed using a slide that slides along the second face 81 starting from the face 83;

[0151] F. Applying pressure P on the second face 81 using the holding tool of the folding device.

[0152] In the above method herein, the sheet insulation 37a is coated with adhesive. In a variant, the winding portion 22a is coated with adhesive and between steps D and E, an adhesive layer is applied to the sheet insulation superposed with the second face 81 so as to allow the portion of the sheet insulation folded in step E to be fixed.

[0153] The present invention is not limited to this method of adhesive application or to the use of an adhesive coating device, and the application of the adhesive may be performed manually.

[0154] Next, the rectilinear portions 22a and 22b of the winding 22 surrounded by the sheet-like insulating member 37a or 37b are inserted into the notch 21 of the ring 25 by radial movement toward the inside of the notch 21. Two rectilinear winding portions 22 with different phases are successively inserted into the same notch 21. The two rectilinear portions 22a and 22b of the winding 22 belonging to the notch 21 are radially superposed and oriented so that the faces 60 of the two windings are oriented toward each other.

[0155] In an additional step, the yoke 29 is attached to the ring 27 by sliding the dovetail 52 into the mortise 50. The yoke 29 may be preheated so that it will expand and make it easier to insert the yoke 2 onto the ring 25. After the yoke is inserted onto the ring 25, the yoke may contract as it cools so that a minimum gap between the ring 25 and the yoke 29 may be achieved.

[0156] As a variant or in addition, the ring 25 may be pre-cooled in order to shrink the ring and make the insertion of the yoke 29 easier.

[0157] Fig. 6A and Figure 6B The embodiment shown is similar to Figures 1 to 5 The embodiments differ in the manner in which the sheet-like insulating members 37a and 37b are wound around the winding portions 22a and 22b.

[0158] exist Fig. 6A In the embodiment shown, the sheet-like insulating members 37a and 37b are wound slightly more than once around the corresponding winding portion 22a or 22b. Each longitudinal edge 54a or 54b of the sheet-like insulating member 37a or 37b overlaps a layer of the same sheet-like insulating member 37a or 37b and a face 60a or 60b of the same winding. Thus, the winding portions 22a and 22b are insulated from the notch by a single thickness of the sheet-like insulating member 37a or 37b, and the winding portions 22a and 22b are insulated from each other by two thicknesses of the sheet-like insulating member 37a and two thicknesses of the sheet-like insulating member 37b, i.e., four thicknesses of the sheet-like insulating member.

[0159] exist Figure 6B In the embodiment shown, the sheet-like insulating members 37a and 37b are wound so that the longitudinal edges 54a and 54b of the sheet-like insulating members 37a and 37b face each other on the faces 60a and 60b instead of overlapping. The winding portions 22a and 22b of the slot 21 are placed in the slot 21 so that the faces 60a and 60b, through which the longitudinal edges 54a and 54b of the sheet-like insulating members 37a and 37b overlap, are both oriented toward the opening 28. The winding portions 22a and 22b are insulated from the slot 21 by one thickness of the sheet-like insulating member 37a or 37b, and the winding portions 22a and 22b are insulated from each other by the discontinuous thickness of the sheet-like insulating member 37b and the continuous thickness of the sheet-like insulating member 37a. In this embodiment, the surface of the winding portion 22a or 22b can be coated with an adhesive as an alternative or supplement to the adhesive coating of the sheet-like insulating member.

[0160] exist Figure 6CIn the embodiment shown, each winding section 22a and 22b is insulated from the outside by two U-shaped sheet-like insulating members 37a or 37b. The two sheet-like insulating members 37a or 37b are placed end to end around the corresponding winding section 22a or 22b and overlap at least partially, in particular on the faces 60a and 61a or 60b and 61b oriented toward the opening of the air gap and the slot 21. The winding sections 22a and 22b are insulated from the slot 21 by one thickness of the sheet-like insulating members 37a or 37b, and the winding sections 22a and 22b are insulated from each other by two thicknesses of the sheet-like insulating members 37a and 37b, each thickness being formed by one of the sheet-like insulating members 37a or 37b.

[0161] exist Figure 7 In the illustrated variation, the sheet-like insulating member 37 a or 37 b is not pasted to the surface of the corresponding winding portion 22 a but is attached at both ends thereof using adhesive tape 62 .

[0162] exist Figure 8 In the variant shown, the sheet-like insulating member 37a or 37b is an adhesive tape wrapped around the winding portion 22a. Successive turns of the adhesive tape partially overlap in order to provide good insulation. In this embodiment, the adhesive tape is preferably made of mica / polyester.

[0163] Of course, the invention is not limited to the exemplary embodiment that has just been described, and the rotor may be a wound rotor instead of a permanent magnet rotor.

[0164] The expression "having" should be understood as being synonymous with "comprising at least one".

Claims

1. A method for manufacturing a stator (2) of an electric machine, the method comprising: a toothed ring (25) comprising teeth (23) joined together by material bridges (27) and notches (21) defined between the teeth (23) and open radially towards the outside; - a winding (22) produced outside the notch (21); as well as - a yoke (29) configured to be attached to the toothed ring (25), The method comprises the following steps: attaching at least one sheet-like insulating member (37a, 37b) to at least a portion (22a, 22b) of each winding of all said windings, said sheet-like insulating members each comprising two opposite longitudinal edges extending substantially along the longitudinal axis of the associated said winding portion, said winding portion being rectangular in cross-section, and the two opposite longitudinal edges of each sheet-like insulating member extending on the same face of the corresponding said winding portion, the longitudinal edges of each sheet-like insulating member contacting each other or facing each other on said face without overlapping; Inserting the winding portion (22a, 22b) with the insulating member (37a, 37b) into the slot (21) by a radial movement directed towards the interior of the slot (21); as well as Assembling the yoke (29) onto the radially outer surface of the ring (25) to radially close the notch (21), The winding portions inserted into the notch are each spaced apart from the inner surface of the notch by at least two thicknesses of the sheet-like insulating member, and the winding portions inserted into the notch are spaced apart from each other by at least four thicknesses of the sheet-like insulating member.

2. The method according to claim 1, wherein: When the winding (22) with the insulating element (37) has been inserted into the slots (21), the insulating element (37) extends in each slot (21) over the entire height of the slot (21).

3. The method according to claim 2, the sheet-like insulating members (37a, 37b) protruding axially from the slot (21) on each side of the slot (21) after being inserted.

4. The method according to claim 1, each sheet-like insulating member (37a, 37b) at least partially overlaps itself.

5. The method according to claim 1, wherein each winding portion (22a, 22b) is placed in the corresponding slot (21) so that the longitudinal edge (54) of the corresponding sheet-like insulating member (37a, 37b) extends on a surface of the winding portion (22a, 22b) oriented toward the opening of the slot (21) or toward the portion (22a, 22b) of the winding inserted into the slot (21).

6. A method according to claim 1, the sheet insulation (37a, 37b) being in the form of a tape wound around the winding portions (22a, 22b).

7. The method according to claim 1, wherein: The sheet-like insulating members (37a, 37b) are fixed to the winding (22) on at least a portion of the surface of the winding (22) by bonding using an adhesive.

8. The method according to claim 1, wherein: Each sheet-like insulating member (37a, 37b) is fixed to the winding part (22a, 22b) at least at one of its longitudinal ends by using adhesive bonding on all or part of the sheet-like insulating members and / or on all or part of the corresponding winding part, or by using at least one adhesive tape.

9. The method according to claim 1, each winding portion (22a, 22b) being covered with a single sheet-like insulation (37a, 37b).

10. The method according to claim 1, each winding portion (22a, 22b) being covered with at least two sheet-like insulation pieces (37a, 37b) at least partially overlapping each other or having contacting edges.

11. The method according to claim 1, each winding portion (22a, 22b) is covered with two sheet-like insulating members (37a, 37b) formed in a U-shape and fixed end to end on the corresponding winding portion (22a, 22b).

12. The method according to claim 1, wherein the winding (22) has a substantially rectangular cross-section, the step of fixing the sheet-like insulating member (37a, 37b) to each of the winding parts (22a, 22b) comprising the following sub-steps: - Lay the sheet-like insulating members (37a, 37b) flat; - positioning the first face (80) of the winding on the sheet-like insulating member (37a, 37b) by applying pressure (P) to the portion of the winding (22a, 22b) in contact with the sheet-like insulating member (37a, 37b) opposite to the first face (80) so as to maintain contact between the sheet-like insulating member (37a, 37b) and the first face (80) of the winding; - applying the two free sides of the sheet-like insulation (37a, 37b) to two opposite sides (82, 83) of the winding; - folding one of the free folded portions of the sheet-like insulating member (37a, 37b) onto the second surface (81), and then folding the remaining free folded portion of the sheet-like insulating member (37a, 37b) onto the second surface (81), wherein the sheet-like insulating member (37a, 37b) is arranged relative to the width of the corresponding winding so that the end of the sheet-like insulating member overlaps with the second surface (81); and - applying pressure to the second face (81) of the winding wrapped in the sheet-like insulating member (37a, 37b), The sub-step is performed using a suitable folding device, which includes a folding wing capable of folding the sheet-like insulating member (37a, 37b) onto the side surfaces (82, 83), a sliding member capable of folding the two folded portions of the sheet-like insulating member (37a, 37b) onto the second surface (81), and a holding tool capable of holding the winding (22) in place and applying pressure to the second surface (81) of the winding.

13. The method according to claim 1, wherein: During the step of inserting said winding portions (22a, 22b), each notch receives at least two winding portions (22a, 22b).

14. A method according to claim 13, each winding part (22a, 22b) is placed in the corresponding groove (21) so that the longitudinal edge (54) of the corresponding sheet insulation (37a, 37b) extends on the face of the winding part (22a, 22b) oriented toward the other winding part (22a, 22b).

15. The method according to claim 1, wherein the sheet-like insulating member (37a, 37b) is made of a flexible electrically insulating material.

16. The method of claim 1, wherein the sheet insulation extends only over a linear winding portion.

17. The method according to claim 8, wherein: The at least one adhesive tape spans across the sheet-like insulating member (37a, 37b) and the winding portion (22a, 37b).

18. A stator (2), comprising: - a radially inner ring (25), said ring (25) comprising: o teeth (23), with slots (21) formed between the teeth (23), the slots (21) opening radially outward; and o bridges of material (27) each connecting two adjacent teeth (23) at their base on the air gap side and defining the bottom of the notch (21) between these teeth; and - a radially outer yoke (29) attached to the ring (25); - windings (22), said windings (22) being placed in said slots (21) in a dispersed manner, each slot (21) having at least a winding (22) of a first phase and a winding (22) of a second phase different from the first phase, at least one sheet-like insulating member (37a, 37b) at least partially surrounding each of said windings (22), said sheet-like insulating members each comprising two opposite longitudinal edges extending substantially along the longitudinal axis of the associated said winding portion, said winding portion having a rectangular cross section, and the two opposite longitudinal edges of each sheet-like insulating member extending on the same face of the corresponding said winding portion, the longitudinal edges of each sheet-like insulating member contacting each other or facing each other on said face without overlapping, The winding portions inserted into the notch are each spaced apart from the inner surface of the notch by at least two thicknesses of the sheet-like insulating member, and the winding portions inserted into the notch are spaced apart from each other by at least four thicknesses of the sheet-like insulating member.

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