EP2859648A2

EP2859648A2 - Insulating element for electric machine stator

Info

Publication number: EP2859648A2
Application number: EP13730035.6A
Authority: EP
Inventors: Jean-Claude LABROSSE; Benoit WALME
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2012-06-12
Filing date: 2013-06-04
Publication date: 2015-04-15
Also published as: WO2013186459A3; FR2991831B1; WO2013186459A2; FR2991831A1; CN104584394A

Abstract

The invention essentially concerns an insulating element (200) for a stator (300) of an electric machine, characterized in that it comprises: an annular support (201); and arms (202) distributed circumferentially about the support (201) and extending radially relative thereto from the internal periphery of the support (201) towards the interior of the insulating element; as well as rims (206) extending on either side of the arms (202), the insulating element (200) having an abutment face (207) which is to be placed flat against an end face of the stator (300).

Description

INSULATING ELEMENT FOR STATOR OF ELECTRIC MACHINE

[01] TECHNICAL FIELD OF THE INVENTION

[02] The invention relates to an insulating element for an electric machine stator. The invention finds a particularly advantageous, but not exclusive, application with air conditioner refrigerant compressors for a motor vehicle.

[03] STATE OF THE ART

[04] Electrical machines are known having a stator and a rotor secured to a shaft ensuring the movement of a scroll compressor, also known as "scroll compressor". Such a system comprises two spirals interposed as pallets for pumping and compressing the refrigerant. In general, one of the turns is fixed, while the other moves eccentrically without turning, so as to pump and trap and compress fluid pockets between the turns. Such a system is for example described in EP1 865 200.

[05] The stator comprises a body made of laminated sheet for reducing the eddy current. The body has at its outer periphery an annular wall, called a yoke, and arms coming from the inner periphery of the annular wall having an outer periphery in contact with a housing that comprises the rotating electrical machine. This housing, also called housing, is configured to rotate the rotor shaft via ball bearings and / or needle as can be seen for example in Figures 1 and 2 of EP 1 865 200.

[06] The stator arms are radially and axially oriented. They are distributed on the wall of the stator body and extend towards the inside of the stator towards the rotor. An air gap exists between the free end of the arms, defining the inner periphery of the stator body, and the outer periphery of the rotor, which may be a permanent magnet rotor. The arms define with the annular wall notches open towards the inside and intended to receive coils, for example in the form of coiled coils each around an arm, for forming a polyphase stator for example of the three-phase type.

[07] OBJECT OF THE INVENTION

[08] The invention aims to optimize the insulation of the stator vis-à-vis its environment.

[09] For this purpose, the invention proposes an insulating element for an electric machine stator characterized in that it comprises:

an annular support having an internal periphery,

circumferentially distributed arms around the support extending radially with respect to the support from the inner periphery of the support towards the inside of the insulating element, as well as

- flanges extending on both sides of the arms,

- This insulating element having a bearing face intended to be pressed against an end face of the stator.

[010] In one embodiment, the support comprises anchor son of stator coil systems located on the support near the arms.

[011] In one embodiment, each anchoring system is formed by a stud and a groove formed around the stud, the groove has a generally U-shaped having two branches facing each other, two ends of these branches opening on the side of the inner periphery of the support.

[012] According to one embodiment the studs are circumferentially oblong

[013] According to one embodiment, the pads, generally parallelepiped shape, have substantially flat longitudinal faces or slightly rounded and transverse faces connecting the longitudinal faces.

[014] In one embodiment the side faces of the pads are rounded. [015] In one embodiment, a median plane of a pad is angularly offset relative to a median plane of the corresponding arm.

[016] In one embodiment, the side of the support face, the arms, the flanges and an inner periphery of the support comprise recesses for receiving ends of notch insulators positioned within notches of the stator.

[017] In one embodiment, the recesses of the arms are delimited by a face substantially perpendicular to an axis of the support and an orthogonal face substantially parallel to the lateral faces of the arms,

the recesses of the flanges, which lie in the continuity of the recesses of the arms, are delimited by a face substantially perpendicular to the axis of the support and an orthogonal face which extends parallel to faces of the flanges facing towards the support,

the recesses formed in the inner periphery of the support, which lie in the continuity of the recesses of the arms, are delimited by a face substantially perpendicular to the axis of the support, and an orthogonal face which extends parallel to faces of the internal periphery of the support.

[018] In one embodiment, the insulating element comprises strand holding systems of winding son located on the support of the side opposite the bearing face.

[019] In one embodiment, each strand holding system comprises a base and a tongue extending in a radial plane on a face of the base facing the outside of the support.

According to one embodiment, each base of the axially extending strand holding systems has a trapezoidal shape in cross-section.

[021] In one embodiment, the strand holding systems are interposed between two successive anchoring systems so that there is alternation between the anchoring systems and the strand holding systems on the circumference of the support. [022] According to one embodiment, the support further comprises on its bearing surface at least two latching devices to facilitate the angular positioning of the insulating member on the end face of the stator.

[023] In one embodiment, the support comprises on its bearing surface recesses for coming opposite stator rivets located on the same circumference.

According to one embodiment, between two successive arms, the faces of the support delimiting the inner periphery of the support are inclined relative to each other in a V-shape.

[025] BRIEF DESCRIPTION OF THE FIGURES

[026] The invention will be better understood on reading the description which follows and on examining the figures that accompany it. These figures are given for illustrative but not limiting of the invention.

[027] Figures 1a and 1b shows perspective views from above and below of an electrically insulating member according to the invention;

[028] Figure 2 shows a detailed view of the recesses of the insulating member according to the invention for receiving the stator slot insulators;

[029] Figure 3 shows a top view of the arms of the insulating member according to the invention;

[030] Figure 4a shows a top view of a coil wire anchoring system of an insulating member according to the invention;

[031] Figure 4b shows a sectional view of the anchoring system according to the plane D-D of Figure 4a;

[032] Figure 5a shows a top view of a latching device of the insulating member according to the invention;

[033] Figure 5b shows a sectional view of the latching device along the plane BB of Figure 5a; [034] Figure 6 shows in perspective view from above an assembled stator provided with the insulating member according to the invention;

[035] Figure 7 shows in perspective the stator of Figure 6 seen from below;

[036] Figure 8a and 8b shows perspective views from above and below of the other electrically insulating member;

[037] Figures 9 and 10 are front views of the front and rear ends of the stator of Figures 6 and 7;

[038] Figure 1 1 is a perspective view of the stator of Figures 6 and 7 without the coils;

[039] FIG. 12 shows the contact zone between an arm of the insulator and a stator arm.

[040] The identical, similar or similar elements retain the same reference from one figure to another.

[041] DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

[042] Figures 1a and 1b and 12 show an electrically insulating member 200 for rotating electric machine stator, such as an air conditioner refrigerant compressor for a motor vehicle. In a variant, the machine consists of an alternator or an electric motor. The element 200 may be moldable plastic, for example PA 6.6. The plastic element 200 may be reinforced with fibers, such as glass fibers. This element 200 comprises at its outer periphery an axially annular support ring 201 having an axial orientation, and circumferentially distributed arms 202 which extend radially from the inner periphery of the support 201 towards the inside of the device. the element 200. These arms 202 each end at their free end by a flange 205 which extends circumferentially on either side of the arm 202 and axially in a direction opposite to an internal bearing surface 207 of the element 200. The function of the rim 205 is to retain in the radial direction an excitation winding wound around a radial arm 302 of each pole of the stator 300 visible in FIGS. 6, 7 and 11. For the record, it will be recalled that the stator 300 comprises a body in the form of a bundle of sheets having at its outer periphery an annular wall 301 (FIG. 11), called a cylinder head, and arms 302 coming from the inner periphery of the wall. annular 301. These arms are circumferentially evenly distributed and extend inward towards the rotor of the machine such as a permanent magnet rotor. The arms 302 delimit two by two notches 308 and have at their free end unreferenced returns.

[043] As shown in Figure 12, the bearing face 207 is intended to be pressed against a radial end face 307 of the stator 300 and this element 200 has an opposite outer face the bearing face 207. The arms 202 are regularly distributed on the inner periphery of the support 201 and are intended to bear against the arms 302 of the stator 300 of corresponding shape. In this case, the arms 202 of the insulating element are here in number 15, as the arms 302 of the stator 300.

[044] The arms 202, the flanges 205, and the inner periphery of the support 201 delimit notches 208 having a shape and dimensions corresponding to the notches 308 of the stator 300. More specifically, as shown in FIG. 3, the arms 202 comprise lateral faces 210 of radial orientation; while the flanges 205 have a face 21 1 facing outwardly of the notches 208. The flanges 205 also have two faces 212 on either side of the arm 202 facing inwards of the notches 208. These faces 212 are inclined at an angle A with respect to the lateral faces 210. The arms 202 are symmetrical with respect to their median plane P1 (see Figure 1b) extending radially with respect to the axis X.

[045] Between two successive arms 202, the inner periphery of the support

201 has two faces 214 which extend perpendicularly to the arms

202 and intersect along a line referenced D1 perpendicular to the sheet of Figure 3. The faces 214 defining the inner periphery of the support 201 are thus inclined relative to each other between two arms 202 In a plane perpendicular to the X axis, the angle B formed between, on the one hand, the line D2 passing through the axis X and the line D1 and, on the other hand, the straight line D3 passing through the median plane P1 of an arm 202 is relatively small, for example of the order of ten degrees.

[046] The notches 208 are each delimited by the two inclined faces 214 of the inner periphery of the support 201, the two side faces 210 of the arms 202 facing each other and the two faces 212 of the corresponding flanges 205.

[047] The notches 308 of the stator have the same shape as the notches 208. Note the presence of an opening between two edges of the same notch 208, 308. These openings allow the passage of a needle for forming coils belonging to the polyphase winding of the stator 300 as described below. The free ends of the arms 202, 302 delimit, in known manner, an air gap with the outer periphery of the rotor of the rotating electrical machine, such as a rotor with permanent magnets.

[048] As shown in Figures 1b and 2, the side of the bearing face 207, the arms 202, the flanges 205 and the inner periphery of the support 201 each comprise recesses 216 made in the thickness of the material intended to receive (Figures 1 1 and 12) the notch insulator ends 400 of the stator 300. Indeed, the stator 300 is equipped with notch insulators 400 in the form of a thin membrane, made in a electrically insulating material and heat conductor, for example an aramid material of Nomex type (trademark). This thin membrane is folded so that each notch insulator is pressed against the axial inner walls 306 of the stator 300 between two adjacent poles. The ends of the notch insulators which protrude axially from the stator 300 may be housed inside the recesses 216 of the insulating element 200 as can be seen in FIG. 12. These insulators 400 have a small thickness (0.24 mm at the Figure 12). The recesses 216 have a depth adapted to that of the insulator 400 (0.5 mm in Figure 12).

[049] These recesses 216 of the arms 202 are delimited by a face substantially perpendicular to the X axis and an orthogonal face substantially parallel to the lateral faces 210 of the arms 202. The recesses 216 of the flanges 205, which lie in the continuity of the recesses 216 of the arms 202, are delimited by a face substantially perpendicular to the X axis and an orthogonal face which extends in parallel. to the faces 212 of the flanges facing the notches 208. The recesses 216 formed in the inner periphery of the support 201, which lie in the continuity of the recesses of the arms 202, are delimited by a face substantially perpendicular to the axis X and a face orthogonal which extends parallel to the faces 214 of the inner periphery of the support 201. Thus, the recesses 216 follow the outline of the notches 208.

[050] On the outer face, the support 201 comprises, according to one characteristic, anchoring systems 220 shown in Figures 1, 4a and 4b, for maintaining and guiding the son of the polyphase winding of the stator 300 having coils 600 (Figures 6, 7, 9 and 1 1), in particular the input son of these coils 600. These anchoring systems 220 here in the same number as the arms 202 are located on the support 201 near the outer periphery each anchoring system 220 is formed by a stud 223 and a groove 224 U-shaped formed around the stud 223. The stud is circumferentially oblong and has two longitudinal faces, which may be of rounded shape, and two lateral faces, which may be rounded, connecting the longitudinal faces, This groove 224 is delimited by lateral faces of the stud 223, here rounded, and walls of the support 201 located around the stud 223. As shown in FIGS. 4a and 4b, the two ends of the branches 228 of the U facing one another and substantially parallel to each other open on the side of the arms 202 on the wall delimiting the inner periphery of the support 201. On the circumference of the support 201, the median plane P2 of a stud 223 is preferably angularly offset with respect to the median plane P1 of the corresponding arm 202 (see Figure 1a). In this embodiment, the median plane P2 of a stud 223 is preferably slightly offset angularly with respect to the median plane P1 of an arm 202.

[051] During the winding operation, the son of the coils 600 pass through the grooves 224 bearing on the side faces of the pads 223 which thus allow to guide and maintain the son of the coils wound around of pad 223. Preferably, the pads 223, of generally parallelepipedal shape, comprise substantially planar or very slightly rounded longitudinal faces and transverse faces 223, constituting the lateral faces of the pad 223, connecting the longitudinal faces. These faces 223 are rounded in order to avoid hurting the son of the coils. The studs 223 have a height H1 measured in the axial direction slightly larger than the depth H2 of the grooves 224, so that each stud 223 slightly projects beyond the walls delimiting the groove 224 on the opposite side of the bearing face 207.

[052] As visible in Figures 1a, 1b and 6, the support 201, according to one feature, also comprises on its outer face 230 strand holding systems 236. These systems 230 are interposed between two systems of anchorage 220 successive. There is thus an alternation between the anchoring systems 220 and the 230 systems for maintaining strands. The holding systems 230 are each located between two successive arms 202. To maintain the strands 236, each holding system 230 comprises an axial extension base 232 having a trapezoid-shaped cross section and a tongue 233 positioned in the upper part of the face of the base 232 facing the outside of the support. 201. This face turned outward is preferably flat. The tongue 233 extends in a radial plane and is preferably at a height corresponding to the thickness of the strands 236.

[053] As shown in Figure 6, the tongue 233 thus holds a holding wire 237 bearing against one side of the tongue 233 facing the bearing face 207 of the support 201 and the face of the base 232 facing outward of the support 201. The holding wire 237 also bears against the lateral faces of the base 232 and passes over the strands 236 and below the stator bunches so as to keep the strands 236 pressed against the bunches of the coils 600. that the buns correspond to the axial end portions of the coils 600 which protrude axially with respect to each radial outer end face of the stator. [054] Each strand 236 is formed of several son twisted coils 600 corresponding to a phase of the stator. In this case, since the stator 300 has three phases and 15 coils, each strand 236 comprises wires associated with five coils 600. In a variant, a system for holding the strands 236 is alternated after a set of several anchoring systems 220. for example two or three. As clearly visible in FIG. 4b, there is a horizontal shoulder between the face 21 of the support 201 delimiting the groove 224 and a lateral face 22 of the base 232.

[055] On its bearing face 207, the support 201 of the insulating member 200 comprises at least two clipping devices 242 (clipping) shown in Figures 1b, 5a and 5b, to facilitate the angular positioning of the insulating element 200 and thus the centering of the insulating elements 200 on the end face of the stator during assembly. For this purpose, the devices 242 are intended to cooperate by clipping (clipping) with corresponding openings provided on each radial end face of the stator 300. In one embodiment, the devices 242 are each formed of two portions 244 of cylinder having flat faces facing each other. These flat faces are separated by a space allowing the elastic deformation of the two portions 244 towards each other during their insertion inside the openings of the stator 300. The free ends of the cylindrical portions 244 are chamfered.

[056] On the bearing face, the support 201 also includes recesses 250 shown in Figures 1b and 2 for example of circular shape intended to come opposite stator rivets 300 located on the same circumference. These rivets, advantageously made of non-magnetic material such as stainless steel, pass axially through the stack of sheets of the stator 300 to ensure the maintenance of the sheets and formation of a manipulable and transportable assembly. Thus, the bearing face 207 of the insulating member 200 does not interfere with the rivets of the sheet package.

[057] Of course, as best seen in Figures 7 and 1 1, another electrically insulating member 200 'is located at the other end radial face of the stator 300. This insulator 200' is the image insulation 200. It has a support 201 ', 202 arms with ledges 205 from the inner periphery of the support 201 ', the notches 208, the recesses 216 for receiving the notch insulation 400 and two devices 242 snap (clipping). This insulator 200 'differs from the insulator 200 only by the shape of its support 201'. More precisely, the insulating element 200 'has a support part devoid of anchoring systems 220 and holding system 230. Like the insulator 200, the electrically insulating element 200' may be made of moldable plastic, for example in PA 6.6. The plastic element 200 'may be reinforced with fibers, such as glass fibers.

[058] As can be seen from the description and the drawings, the arms 202 of the insulators 200 and 200 'and the insulator 400 electrically isolate the coils 600 from the winding of the stator 300, here of the three-phase type, with respect to the stator plates 300. They also protect the son of the windings 600, during the winding of the conductive son around the arms of the stator 300. Specifically the son of the coils 600, such as copper or aluminum son covered with a electrically insulating layer, such as enamel, are each wound around an arm 302 of the stator and associated arms 202 of the insulating elements 200, 200 '. There is a passage between two arms 202, 302 consecutive as visible in Figures 9 and 10 so that the same notch receives two half coils 600.

[059] In an alternative embodiment, the arms 202 of the insulating member 200 'may have on their outer face inclined grooves to facilitate the change of rank during the winding operation of winding a conductive wire around the different poles to get the stator windings. The excitation windings of each pole are electrically connected to each other by connecting son in series or in parallel. It is the same for the holding member 200 which may have grooves to facilitate winding during the winding operation. The grooves are not inclined in this case.

[060] In one embodiment, the insulating member 200 has a diameter L1 of the order of 10cm. This diameter L1 is slightly smaller than the external diameter of the stator 300 to allow the passage of mounting rods of the electric machine along the lateral face of the stator 300. For this purpose the stator has at its outer periphery recesses 321 for the passage of the tie rods. It is the same insulating elements 200, 200 'as shown in Figure 7. The tie rods are located on a circumference of diameter greater than that of the fastening rivets of the stator plate package. The element 200 has a height L2 of the order of 1 1 mm. The grooves 224 have a width of the order of 1 mm. The pads 223 have an end located at a height L3 of the order of 9mm relative to the bearing surface 207. The arms 202 have a length L4 of the order of 15mm. The faces 212 of the flanges 205 are inclined with respect to the lateral faces 210 of the arms, for example at an angle A of the order of 60 degrees. The angle B formed between on the one hand the line D2 passing through the axis X and the line D1 and on the other hand the straight line D3 passing through the median plane of an arm is for example of the order of one ten degrees. The latching devices 242 are separated from each other by an angle of the order of 170 degrees. The depressions 250 have a depth slightly greater than 1 mm. In the embodiment shown, the insulating member 200 comprises 15 arms, 15 holding systems as well as 15 anchoring systems for a coil stator. Of course, this number of elements as well as the dimensions of these elements will be adapted according to the configuration of the stator 300 to be isolated, and in particular the number and the size of the arm 301 of the stator, as well as the size of the wire of coil. The insulating element 200 is made of a non-conductive material, for example a fiberglass-based plastic material.

[061] During assembly, the holding member 200 is pressed via its bearing face 207 against an end face of the stator 300 so that the latching devices 242 cooperate with the corresponding openings of the stator 300. The same is true of the 200 'insulation. The positioning of the elements 200, 200 'is such that the ends of the notch insulators previously positioned inside the notches 308 (Figure 1 1) of the stator 300 which protrude axially from the stator 300 are housed inside the recesses 216 of the insulating member 200.

[062] The coil winding operation is then carried out using a centrally hollow needle to allow passage of the wire which moves circumferentially, axially and radially with respect to the stator. The wires of the coils are then wrapped around the formed assembly by the arms 302 of the stator 300 and the arms 202 of the insulating elements 200, 200 'to form the different poles. Thus the coils 600 have two ends, called buns, arranged on either side of an arm 302 of the stator. The coils 600 here have a trapezoidal shape as can be seen in FIG. 7. One end of the wires guided by the lateral faces of the pads passes through the grooves 224 so as to be held in position by the anchoring systems 220. The buns of the coils 600 are retained by the flanges 205 of the arms 202. It will be noted that a passage exists for the needle between two consecutive flanges 205 of the same notch 208, 308.

[063] The son of the coils of each phase are grouped in strands 236 positioned on the outer periphery of the buns of the coils 600 following a circular path. To keep the strands 236 in position, the holding wires 237 are positioned against the rear faces of the holding systems 230 and against the face of the tongue facing the bearing face 207. The holding wires 237 are also positioned against the inclined faces of the base 232 so as to return to the X axis and pass above the strands 236. The wire 237 passes under the strands 236 and then hang around a new holding system 230. The wire 237 The holder follows a slot-like path around the entire circumference of the holder 201 to move from a holding system 230 to another.

[064] It will be appreciated that the strands 236 are arranged to form passages as shown in FIGS. 8 and 9.

[065] As shown in the drawings and in particular in Figure 7, the positioning of the recesses 321 corresponds to the angular positioning of the openings in the closing flanges of the machine ensuring the passage of the tie rods, said flanges belonging to the casing bearing the stator body. More specifically, this housing here comprises three parts, namely an intermediate portion carrying the annular wall of the stator of the electric machine, such as a refrigerant compressor of a motor vehicle air conditioner, and two flanges arranged on either side of the intermediate part. One of the hollow-shaped flanges carries the "scroll" of the compressor, while the other flange carries the control electronics of the compressor integrated into the electric machine and protruding axially. The tie rods, for example in the form of screws, connect the flanges together by passing through the recesses 321 of the stator, for example, mounted to hooping via its annular wall 301 in the intermediate portion sandwiched between the flanges. Advantageously, the intermediate portion comprises hooping sectors for the hoop-mounting of the wall 301 of the stator. Between two consecutive hooping areas there are passages. These passages are opposite recesses 321. The shrinking sectors are separated from each other by passages. The outer periphery of the wall 301 is in hooping contact with the inner periphery of the hooping sectors. The passages are opposite the recesses 321 so that the tie rods pass through the passages without interfering with the intermediate portion of the housing. The intermediate part may be filled with coolant. This liquid can pass through the spaces between the coils 600 and the strands 236.

[066] Note that the ends of the strands 236 are sheathed for forming projecting ends 236 'axially intended to pass through the sealing flange of the electronics, which comprises an inverter as described for example in the document EP 0 831 580 to which reference will be made. The ends 236 'are configured to be connected to the arm of the inverter as in EP 0 831 580. In this embodiment the rotor of the compressor electric motor is permanent magnets, preferably buried in the rotor. The magnets may be of radial orientation. In this embodiment the rotor comprises a body in the form of a pack of sheets provided with housings, which may be of radial orientation for housing the magnets. The rotor made of laminated sheet may comprise a central core, and arms extending radially relative to the core. These arms each comprise two flanges extending circumferentially on either side of the arms. Permanent magnets are positioned inside housings delimited each by two faces facing each other of two adjacent arms, an outer face of the rotor core, and the edges of the arms having an inner portion generally. constant width from the central core and extended by a second flared portion towards the outer periphery of the stator as described for example in the document FR 1 1 61019 filed 01/12/201 1. Of course, it is possible to provide positioned springs each in a housing of a permanent magnet between the outer face of the core and the inner face of the magnet to ensure a maintenance of the permanent magnet against the edges of the housing with intervention of a flexible blade as described in the Document FR 12 54949 filed on 30/05/2012. Balancing flanges with balancing weights may be located at each end of the rotor laminations as described in FR 12 54949, supra. In FR 12 54949 the rotor comprises ten permanent magnets with beveled internal end. This configuration associated with that of the stator of Figures 1 to 5 allows a good passage of the magnetic flux. The housing of the magnets may be of constant width.

[067] The rotor sheet package is secured to a tree itself integral with the scroll-mobile scroll movable in English- the compressor. In this type of embodiment the compressor has no pulley and the control electronics of the electric motor is integral with a flange being integrated in the compressor. The stator and the rotor of the electric machine are immersed in the refrigerant fluid.

[068] Of course, those skilled in the art can modify the shape of the insulating element 200 of the stator. In particular, it is possible to remove the arms 202 and the edges 205 to retain only the support 201. This support 201 may then comprise only anchoring systems 220 or a combination of anchoring systems 220 and 230 strand holding systems. Alternatively, the support 201 retains only the strand holding systems 230.

[069] Of course the insulation 400 may alternatively be in two parts each in one piece with one of the elements 200, 200 '. The arms 202 may alternatively be in one piece with the insulation 400 advantageously in two parts for forming a coil insulator 600 separate supports 200, 200 '.

The studs 223, circumferentially oblong, may alternatively be oval. These pads 223 may be of parallelepipedal shape with two substantially flat longitudinal faces and transverse faces connecting the longitudinal faces. The edges of the studs 223 are advantageously rounded in rounded form.

The groove 224 therefore has a generally U shape.

The recesses 321 may have another shape and have a flat bottom and two side edges as shown in Figures 6 and 1 1.

Claims

1. Insulating element (200) for a stator (300) of an electric machine characterized in that it comprises:

an annular support (201) having an internal periphery,

arms (202) distributed circumferentially around the support (201) extending radially with respect to the support (201) from the inner periphery of the support (201) towards the inside of the insulating element, as well as

rims (205) extending on either side of the arms (202),

- This insulating member (200) having a bearing face (207) intended to be pressed against an end face of the stator (300).

2. Insulating element according to claim 1, characterized in that the support (201) comprises anchoring systems (220) of coil wires (600) of the stator located on the support (201) near the arms (202). .

3. insulating element according to claim 2, characterized in that each anchoring system (220) is formed by a stud (223) and a groove (224) formed around the stud (223) and in that this groove (224). ) has generally a U-shape having two branches (228) facing one another, two ends of these branches (228) opening on the side of the inner periphery of the support (201).

4. Element according to claim 3, characterized in that the studs (223) are circumferentially oblong.

5. Element according to claim 3, characterized in that the studs (223) are oval.

6. insulating element according to claim 3, characterized in that the pads (223) are of generally parallelepipedal shape and have longitudinal faces substantially flat or slightly rounded and transverse faces connecting the longitudinal faces of rounded shape.

7. insulating element according to one of claims 3 to 6, characterized in that a median plane of a stud (223) is slightly angularly offset relative to a median plane of the arm (202) corresponding.

8. Insulating element according to one of claims 1 to 7, characterized in that the side of the bearing face (207), the arms (202), the flanges (205) and an inner periphery of the support (201) have recesses (216) for receiving ends of slot insulators positioned within stator slots.

9. Insulating element according to claim 8, characterized in that the recesses (216) of the arms (202) are delimited by a face substantially perpendicular to an axis (X) of the support (201) and an orthogonal face substantially parallel to the faces. laterals (210) of the arms (202),

the recesses (216) of the flanges (205), which lie in the continuity of the recesses (216) of the arms (202), are delimited by a face substantially perpendicular to the axis (X) of the support (201) and a orthogonal face extending parallel to faces (212) of flanges (205) facing the support (201),

the recesses (216) formed in the inner periphery of the support (201), which lie in the continuity of the recesses of the arms (202), are delimited by a face substantially perpendicular to the axis (X) of the support (201) and an orthogonal face which extends parallel to faces (214) of the inner periphery of the support (201).

10. Insulating element according to one of claims 1 to 9, characterized in that it comprises systems (230) for maintaining strands (236) of winding son located on the support (201) on the side opposite the face support (207).

1 1. An insulating member according to claim 10, characterized in that each strand holding system (230) (236) has a base (232) and a tongue (233) extending in a radial plane on a face of the base (232). ) facing the outside of the support (201).

12. Insulating element according to claim 1 1, characterized in that each base of the systems (230) for maintaining strands (236) of axial extension has a cross sectional trapezoidal shape.

13. Insulating element according to one of claims 10 to 12 taken in combination with one of claims 3 to 7, characterized in that the systems (230) for maintaining strands are interposed between two anchoring systems (220) successive so that there is alternation between the anchoring systems (220) and the systems (230) for maintaining strands on the circumference of the support (201).

14. insulating element according to one of claims 1 to 13, characterized in that the support (201) further comprises on its bearing face (207) at least two devices (242) latching to facilitate angular positioning the insulating element (200) on the end face of the stator.

15. insulating element according to one of claims 1 to 14 characterized in that the support (201) has on its bearing surface recesses (250) intended to come opposite stator rivets (300) located on the same circumference.

16. Insulating element according to one of claims 1 to 15, characterized in that between two arms (202), successive faces (214) of the support (201) defining the inner periphery of the support (201) are inclined one with respect to the other in a V-shape.