FR3054748B1 - ROTATING ELECTRIC MACHINE HAVING INTERCONNECTOR WITH RADIALLY STACKED COUPLING TRACES - Google Patents

Abstract

The invention relates mainly to a stator (17) of rotating electrical machine, particularly for a motor vehicle, comprising: - a body (21) provided with a yoke and a plurality of teeth extending radially outwardly to from an outer periphery of the yoke, - a polyphase winding (22) having a plurality of coils (36) having coupling portions (46), each coil (36) being wound around a corresponding tooth (23). the stator body (21), and - an interconnector (43) having a plurality of coupling traces (47) provided with connecting tongues (50), said interconnector (43) providing a coupling between coils (36) of different phases via their coupling portion (46), characterized in that the coupling traces (47) of the interconnector (43) are coaxial and stacked radially relative to one another.

Description

The invention relates to a rotary electric machine provided with a radially stacked coupling trace interconnector. The invention finds a particularly advantageous, but not exclusive, application in the field of electrical machines operating in motor mode to ensure the rotational drive of motor vehicle fans.

Such fans installed on the front of the vehicle are intended to generate a flow of air passing through a stack of heat exchangers such as an engine cooler and an air conditioning condenser positioned one behind the other. For this purpose, these fans comprise a helix driven in rotation by a bell-shaped rotor positioned around a stator with external teeth. Indeed, the stator comprises a body provided with a plurality of teeth angularly distributed regularly on an outer periphery of the yoke.

A polyphase winding inserted in the slots of the stator is obtained for example from individual coils each wrapped around a tooth of the stator. An interconnector having a plurality of coupling traces provides coupling between coils of different phases. For this purpose, the coupling traces are provided with connection tongues on which ends of coils are welded.

In existing configurations, the coupling traces are stacked axially on each other, which increases the axial size of the stator making it difficult to integrate the fan at the front of the vehicle. The invention aims to remedy these drawbacks effectively by proposing a rotating electric machine stator, in particular for a motor vehicle, comprising: a body provided with a yoke and a plurality of teeth extending radially outwards to from an outer periphery of the yoke, - a polyphase winding having a plurality of coils having coupling portions, each coil being wound around a corresponding tooth of the stator body, and - an interconnector having a plurality of traces of coupling provided with connection tongues, said interconnector ensuring a coupling between coils of different phases via their coupling portion, characterized in that the coupling traces of the interconnector are coaxial and stacked radially with respect to each other. The invention thus makes it possible, because of the radial stacking between the coupling traces, to reduce the axial size of the machine to facilitate its integration and that of the fan at the front of the motor vehicle.

In one embodiment, the larger diameter coupling trace of the interconnector has an outer diameter smaller than an internal diameter of the yoke of the stator body. This limits the radial size of the stator imposed by its outer diameter.

According to one embodiment, the coupling traces are positioned axially between two axial ends of the winding.

According to one embodiment, the interconnector comprises circular grooves in which are inserted the coupling traces.

In one embodiment, the coupling traces are held inside the snap grooves.

According to one embodiment, the connection tabs bear against ramps formed in the faces of the interconnector delimiting radial housings for the connection tongues.

According to one embodiment, the interconnector comprises a body overmoulded on the coupling traces.

According to one embodiment, the interconnector comprises recesses able to allow a passage of welding electrodes.

In one embodiment, the interconnector forms an insulator of coils.

According to one embodiment, the interconnector comprises a plurality of arms intended to be each pressed against a corresponding end face of a tooth of the stator body and insulating walls intended to be pressed against side faces of corresponding teeth.

According to one embodiment, said stator comprises a coil insulator positioned against an axial end face of the opposite stator body with respect to the interconnector.

In one embodiment, insulating axial walls of the coil insulator and insulating axial walls of the interconnector are spaced axially from one another.

In one embodiment, the insulating axial walls of the coil insulator and / or the insulating axial walls of the interconnector have a height less than half the axial height of the stator body. The invention also relates to a rotating electrical machine, in particular for a motor vehicle, characterized in that it comprises a stator as previously defined.

In one embodiment, the rotating electrical machine is a brushless DC machine. The invention further relates to a motor vehicle fan characterized in that it comprises a rotating electric machine as previously defined. The invention will be better understood on reading the description which follows and on examining the schematic figures that accompany it. These figures are given for illustrative but not limiting of the invention.

Figure 1 is a perspective view of the rotating electrical machine according to the present invention;

FIG. 2 is a perspective view of a portion of the external tooth stator belonging to the rotating electrical machine of FIG. 1;

Figures 3a and 3b are perspective views respectively from above and below of a wound stator according to the present invention provided with an interconnector with overmolded coupling traces;

Figure 4 is a perspective view from above illustrating an alternative embodiment of the wound stator according to the present invention provided with an interconnector with clutched coupling traces;

Figure 5 is a detailed perspective view of the latching device used to secure the coupling traces to the body of the interconnector of Figure 4;

FIG. 6 is an electrical diagram illustrating a first type of triangular coupling of the stator coils according to the invention;

Figure 7 is a schematic view of the front face of the stator on the side of the interconnector illustrating the positioning of the coupling portions between the coils of the different phases for the mounting of Figure 6;

FIG. 8 is a schematic view of the rear face of the stator illustrating the implantation of the routing portions between the coils of the same phase for the assembly of FIG. 6;

FIGS. 9a and 9b are electrical diagrams illustrating variants of triangular coupling of the stator coils according to the invention;

Figs. 10a and 10b are perspective views from above and below of the interconnector according to the present invention;

Figure 11 is a top view of the coupling traces belonging to the interconnector according to the present invention;

Fig. 12 is a perspective view of a coupling trace according to the present invention;

Figure 13 is a sectional view of a connecting tab belonging to a coupling trace of the interconnector according to the invention;

Figure 14 is a perspective view of the coil insulator plated against the rear end face of the stator according to the invention;

Fig. 15 is a perspective view of the rotor of the rotating electrical machine according to the present invention.

Identical, similar or similar elements retain the same reference from one figure to another. In the following description, the so-called "front" side of the stator is located on the side of the interconnector and the so-called "rear" side is located on the opposite axial side.

FIG. 1 shows an example of a rotating electrical machine 10. In this example, it is a brushless DC brushless electric machine also called "Brushless direct curent" (BLDC) in English.

The rotating electrical machine 10 comprises a bell-shaped rotor 11 on which is intended to be fixed a propeller (not shown). The rotor 11 carries on its inner periphery a plurality of permanent magnets 12 forming the poles of the machine 10. The rotor 11 is rotatably mounted on a shaft 13 coming from a heat sink 16 which contains an electronic module for controlling the machine 10.

This rotor 11 surrounds a polyphase stator 17 with the presence of an air gap between the inner periphery of the rotor 11 and the outer periphery of the stator 17.

This X-axis stator 17 is attached to the heat sink 16 intended to be mounted on a support piece, called a nozzle, carrying heat exchangers of the vehicle, such as the heat engine cooler and the air conditioning condenser. For this purpose, fasteners pass through openings made in projecting lugs 18 coming from an outer periphery of the heat sink 16.

The stator 17 comprises a body 21 and a coil 22. More precisely, as can be seen in FIG. 2, the stator body 21 consists, for example, in an axial stack of plane sheets. The body 21 has teeth 23 distributed angularly in a regular manner on an outer periphery of a yoke 24. These teeth 23 delimit notches 27, so that each notch 27 is delimited by two successive teeth 23.

The yoke 24 thus corresponds to the solid inner annular portion of the body 21 which extends between the bottom of the notches 27 and the inner periphery of the stator 17. The notches 27 open axially into the axial end faces of the body 21. The notches 27 are also open radially outwardly of the body 21.

In this example, the stator 17 is provided with tooth roots 28 on the free ends of the teeth side 23. Each tooth root 28 extends circumferentially on either side of a corresponding tooth 23.

The stator 17 also has portions 31 coming from the inner periphery of the yoke 24 projecting radially inwardly from the yoke 24. Each projecting portion 31 has a through axial aperture 32 into which a fixing member penetrates 33, for example a screw as shown in FIG. 3a, for fixing the stator 17 to the heat sink 16.

To obtain the winding 22, several phases are formed by coils 36 each wound around a corresponding tooth 23 of the stator body 21, as illustrated by FIGS. 3a, 3b, and 4.

According to a preferred configuration, the winding 22 of three-phase type is formed by 18 coils 36 and the rotor 11 has 12 poles or 12 permanent magnets. The 18 coils are formed from the same continuous wire 37 whose diameter is less than 1.5 mm. For example, this wire 37 may have a diameter of the order of 1.2 mm. The electrically conductive wire 37 is preferably covered with a layer of electrically insulating material such as enamel.

Advantageously, the winding 22 is a three-phase winding formed from three sets 40 of coils 36 coupled in a triangle. According to a first embodiment shown in FIG. 6, each set 40 comprises three branches 41 electrically connected in parallel, each branch 41 having two coils 36 electrically connected in series. According to a second embodiment shown in FIG. 9a, each set 40 comprises two branches 41 electrically connected in parallel, each branch 41 having three coils 36 electrically connected in series. According to a third embodiment shown in FIG. 9b, each set 40 comprises six coils 36 electrically connected in parallel.

An interconnector 43 shown in FIGS. 3a, 3b, 4, 10a and 10b provides a coupling between coils 36 of different phases U, V, W via their coupling portion 46. Each coupling portion 46 thus corresponds to a portion of the wire 37 extending between two coils 36 of different phases and electrically connected to the interconnector 43.

More specifically, the Y axis interconnector 43 comprises a body 44, made of an electrically insulating material, for example a plastic material, and a plurality of coupling traces 47 provided with connection tongues 50 on which the coupling portions are welded. 46 who have previously been stripped of their enamel. It should be noted that when the interconnector 43 is mounted on the stator 17, its axis Y is substantially coincident with the axis X of the stator 17.

In the embodiment of FIGS. 3a and 3b, the body 44 is overmolded on the coupling traces 47.

Alternatively, as shown in FIGS. 4 and 5, the coupling traces 47 in the form of an open ring are inserted in circular grooves 51 of the body 44 of corresponding shape. The coupling traces 47 are held inside the grooves 51, for example by snapping. For this purpose, a radial edge of the connecting tongues 50 bears against ramps 54 formed in faces of the interconnector 43 defining radial housings for the connecting tongues 50. The ramps 54 are here made in two faces in screws. with respect to the body 44 extending in a substantially radial direction.

There is a first coupling trace 47 ensuring the coupling between the coils 36 of a first phase U referenced U1-U6 and the coils 36 of a second phase V referenced V1-V6, a second coupling trace 47 ensuring the coupling between the coils 36 of phase V referenced V1-V6 and the coils 36 of a third phase W referenced W1-W6, and a third coupling trace 47 ensuring a coupling between the coils 36 of the U phase referenced U1-U6 and the coils 36 of the W phase referenced W1-W6. The number of coupling traces 47 can of course be adapted according to the number of phases of the electric machine.

As can be seen in the example of FIG. 11, the coupling traces 47 of different diameters are coaxial and stacked radially relative to one another. The traces 47 are radially spaced relative to each other, so that there is a layer of electrically insulating material between two adjacent traces 47 to ensure their electrical insulation. The insulating layer may be constituted by a portion of the body 44 molded for the embodiment of Figures 3a and 3b or an insulating wall defining a groove 51 for the embodiment of Figures 4 and 5.

Preferably, the coupling trace 47 of larger diameter of the interconnector 43 has an outer diameter smaller than the internal diameter of the yoke 24 of the stator body 21.

In addition, each coupling trace 47 has a body 99 which may have an axial elongation greater than its radial elongation to present a ring shape extending axially with respect to the axis X of the stator 17. Preferably, the body 99 has a shape of an arc of a circle.

The coupling traces 47 are positioned axially between two axial ends of the coil 22, as shown in FIGS. 3a and 3b. In other words, the axial ends of the annular portion of the coupling traces 47 considered without the connecting tongues 50 are positioned between the axial portions of the coils 36 projecting from either side of the stator body 21.

Preferably, the assembly of the interconnector 43 is positioned axially between the two axial ends of the coil 22. This makes it possible to obtain a compact assembly according to the axial and radial dimensions.

In order to facilitate the welding operations, the connection tongues 50 directed radially outwardly of the body 99 of the corresponding coupling trace 47 have end portions 57 situated at the same circumference, as illustrated by FIG. 11. For this purpose, the radial lengths of the tabs 50 located on the internal coupling traces 47 are greater than the lengths of the connecting tabs 50 located on the outermost coupling trace 47 of the radial stack.

The connection tongues 50 furthermore comprise an axial flange 58 of the same dimension so as to be all located at the same axial height with respect to the stator body 21, as shown in FIG. 12.

The connecting tabs 50 of each coupling trace 47 are angularly spaced from each other in a regular manner. In addition, the angular offset between two adjacent coupling traces 47 is made so as to obtain groups 60 of three connection tabs 50 belonging to different traces 47, as shown in FIG. 11. These groups 60 are spaced apart the circumference of the interconnector 43. There is a circumferential alternation between the connection tongues 50 of the different coupling traces 47.

Each connecting tongue 50 preferably comprises a folding portion 63 situated in the extension of the end portion 57 of the tongue 50, as can be seen in FIGS. 12 and 13. Each folding portion 63 makes it possible to ensure the maintaining a corresponding coupling portion 46 of the wire 37.

In order to avoid damaging the coil wire 37 during the deformation of the folding portion 63, each folding portion 63 may include a sear 64 visible in FIG. 13. This sear 64 is defined by a recess at the level of the anchoring end of the folding portion 63 with the connecting tab 50. The sear 64 is applicable in the case where the traces are clipped, which corresponds to the embodiment of Figure 4. In contrast, in the embodiment 3a and 3b corresponding to an overmolding of the coupling traces 47, the folding portions 63 are devoid of jarring 64, especially for reasons of space. Each folding portion 63 then forms a right angle with respect to the corresponding connection tab 50.

To facilitate their implementation, each coupling trace 47 may have a plane of symmetry P1 passing through a connection tab 50. The coupling traces 47 all further have a shape identical to a diameter and a radial length of the connection tongues 50 near. It is thus possible to standardize their manufacture.

In addition, as illustrated by Figures 10a and 10b, the interconnector 43 forms a coil insulator. For this purpose, the body 44 comprises a central annular portion 67 intended to be pressed against the yoke 24. This central annular portion 67 is in the extension of the annular portion 68 of the interconnector 43 having the coupling traces 47. L interconnector 43 further comprises a plurality of arms 71 coming from the annular portion 67. These arms 71 extending radially outwards are intended to be each pressed against a corresponding end face of a tooth 23 of the body. stator 21. In addition, insulating walls 72 located in the extension of the longitudinal edges of the arms 71 are intended to be pressed against side faces of corresponding teeth 23.

Recesses 75 made in the body 44 allow a passage of welding electrodes on either side of the connecting tongues 50. The electrodes displaced in two opposite axial directions can thus come to pinch the connection tongue 50 - portion of the connector assembly. coupling 46 to allow the realization of the weld. For this purpose, the recesses 75 made in the lower part of the body 44 open towards the lower face of the tongues 50. The upper face of the tongues 50 is also disengaged for the contact between the wire of the coupling portions 46 and the tongues 50.

Clearances 76 made in the body 44 allow the passage of the fasteners 33 inside the openings of the projecting parts 31 to fix the stator 17 on the heat sink 16.

In addition, a coil insulator 80 shown in FIG. 14 may be positioned against an axial end face of the stator body 21 opposite to the interconnector 43. This coil insulator 80 has a structure similar to that of the parts. of the interconnector 43 having an electrical insulator function. Thus, the coil insulation 80 comprises a central annular portion 82 pressed against the end face of the yoke 24 opposite the interconnector 43 and a plurality of arms 83 coming from the annular portion 82. These arms 83 extending radially outwardly are intended to be each pressed against a corresponding end face of a tooth 23 of the stator body 21. In addition, insulating walls 84 located in the extension of the longitudinal edges of the arms 83 are intended to be plated against lateral faces of corresponding teeth 23 so as to cover at least partially these side faces. For this purpose, the insulating walls 84 are directed axially, as the insulating walls 72, towards the inside of the stator 17. In other words, the insulating walls 72 and 84 are directed axially towards each other.

Advantageously, the insulating walls 84 of the coil insulation 80 and the insulating walls 72 of the interconnector 43 are axially spaced from one another. The insulating walls 84 of the coil insulation 80 and / or the insulating walls 72 of the interconnector 43 have a height less than half the axial height of the stator body 21. Such a configuration makes it possible to adapt to different stator configuration 17 and in particular stators 17 of different axial lengths to address different electric machine powers, without having to modify the structure of the interconnector 43 or the coil insulator 80.

In addition, because of the tension of the thread 37 between the two insulating faces 72, 84 facing each other, the thread 37 is kept at a distance from the zones of the lateral faces of the teeth 23 which are not covered by the insulating walls 72, 84, so that it is not necessary to use additional insulation-type insulation inside the notches 27 in the space between the two insulating walls 72.

The coupling traces 47 are each provided with a connection terminal (not shown) intended to be connected with a corresponding connection terminal of the electronic control module integrated in the heat sink 16. This module comprises switches, such as transistors MOS type for example, controlled to inject current into the different phases of the electric machine operating in motor mode.

With reference to FIGS. 6, 7 and 8, the operations making it possible to obtain the winding 22 of the stator 17 are described below. The coils 36 are advantageously made from the same continuous wire 37 by means of FIG. a needle device for passing the wire 37 around the teeth 23 of the stator body 21 via a notch opening 87 corresponding to the circumferential space between two adjacent tooth legs 28 (see Figure 2). To make the turns 88 of the coils 36, the needle performs axial movements from top to bottom combined with circumferential movements alternately in one direction and then in another. A relative radial movement between the needle and the tooth 23 of the stator 17 makes it possible to produce the different layers of turns 88.

According to certain implementations, the needle performs all the movements relative to a stator body 21 fixed to obtain the coil 22. In other winding methods, the distribution of movements is performed between the needle and the stator body 21.

Once the first coil 36 has been made, for example the coil U1 of the first phase U, the needle moves three notches 27 to form the second coil U2 of the first phase electrically connected in series with the first coil U1, such as shown in FIGS. 6 and 7. In other words, a space is provided for making the coils of the two other phases between two successive coils 36 of the same phase, for example the coils V4 and W3. The displacement is carried out in such a way that the routing portion 91 between the two coils U1 and U2 of the same phase, here the phase U, extends on the side of the face opposite the interconnector 43 (see FIG. .

Once the second coil U2 has been made, the wire 37 passes through a connection tab 50 to ensure the coupling between the first phase and the second phase (coupling U2-V1 in the figure) before being inserted into the adjacent slot 27 to the second coil U2 to make the first coil V1 of the second phase. The coupling is effected for example by welding the coupling portion 46 to a corresponding connection tab 50 after having stripped the enamel of the coupling portion 46.

After having jumped two notches 27 via a routing portion 91, the second coil V2 of the second phase is produced, then a coupling is effected, via a coupling portion 46, with the first coil 36 of the third phase W1 and so on until a complete winding 22 is obtained.

In other words, the winding 22 is obtained by the alternating production of two coils 36 in series of the same phase and then a coupling between the last coil of the series with a first coil of a new series of two coils belonging to another phase.

The coupling between the coils 36 of different phases is thus performed on one axial side of the stator body 21 via the interconnector 43 and the routing of the wire portions 37 connecting coils 36 of the same phase is carried out, via the portions routing 91, the opposite axial side of the stator body 21 relative to the interconnector 43, as is apparent from Figures 7 and 8. It should be noted that in Figure 8, the arrows F1 indicate the winding direction and therefore the order of realization of the different coils 36.

The coil 22 can thus be made from a single wire. This wire is not cut during the coupling operations with the interconnector 43.

Moreover, as can be seen in FIG. 15, the rotor 11 comprises an annular wall of axial orientation 94 positioned around the stator 17. This annular wall 94 is coaxial with the stator 17. This annular wall 94 extends from a external periphery of an annular wall of radial orientation 95. This annular wall of radial orientation 95 is extended centrally by a sleeve 96 in which is mounted a bearing means 97, such as a ball bearing or needle, for ensure rotational mounting of the rotor 11 on the shaft 13 attached to the heat sink 16. The annular wall of transverse orientation 95 may be perforated to allow the circulation of air inside the machine 10. The annular wall of transverse orientation 95 comprises means 98 for fixing the fan, constituted for example by through openings in which are inserted fasteners, such as screws or rivets.

The plurality of permanent magnets 12 forming the poles of the machine is fixed on an inner periphery of the annular wall of axial orientation 94. The magnets 12, for example of parallelepipedal shape, are preferably made of ferrite. Alternatively, they may however be made of rare earth according to the applications and the desired power of the electric machine 10. The magnets 12 may also be of different shades, it depends on the applications.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention which would not be overcome by replacing the different elements by any other equivalent.

In addition, the various features, variations, and / or embodiments of the present invention may be associated with each other in various combinations, to the extent that they are not incompatible or exclusive of each other.

Claims (12)

1. Stator (17) of rotating electrical machine (10), especially for a motor vehicle, comprising: - a body (21) provided with a yoke (24) and a plurality of teeth (23) extending radially towards externally from an outer periphery of the yoke (24); - a multiphase coil (22) having a plurality of coils (36) having coupling portions (46), each coil (36) being wound around a corresponding tooth (23) of the stator body (21), and - an interconnector (43) having a plurality of coupling traces (47) provided with connection tongues (50), said interconnector (43) providing a coupling between coils (36) of different phases via their coupling portion (46), characterized in that the coupling traces (47) of the interconnector (43) are coaxial and stacked radially relative to each other and in that the interconnector (43) comprises a body (44) overmolded on the coupling traces (47). Stator according to Claim 1, characterized in that the coupling track (47) of larger diameter of the interconnector (43) has an outer diameter smaller than an internal diameter of the yoke (24) of the stator body ( 21). 3. Stator according to claim 1 or 2, characterized in that the coupling traces (47) are positioned axially between two axial ends of the coil (22). 4. Stator according to any one of claims 1 to 3, characterized in that the interconnector (43) has grooves (51) circular in which are inserted the coupling traces (47). 5. Stator according to any one of claims 1 to 4, characterized in that the interconnector (43) has recesses (75) adapted to allow a passage of welding electrodes. 6. Stator according to any one of claims 1 to 5, characterized in that the interconnector (43) forms a coil insulator. Stator according to claim 6, characterized in that the interconnector (43) comprises a plurality of arms (71) each intended to be plated against a corresponding end face of a tooth (23) of the stator body ( 21) and insulating walls (72) intended to be pressed against corresponding lateral faces of teeth (23). 8. Stator according to any one of claims 1 to 7, characterized in that it comprises a coil insulator (80) positioned against an axial end face of the stator body (21) opposite to the interconnector (43). 9. Stator according to claim 8, characterized in that insulating axial walls (84) of the coil insulation (80) and insulating axial walls (72) of the interconnector (43) are spaced axially from each other . 10. Stator according to claim 9, characterized in that the insulating axial walls (84) of the coil insulation (80) and / or the insulating axial walls (72) of the interconnector (43) have a height less than half of the axial height of the stator body (21). 11. Rotating electrical machine, especially for a motor vehicle, characterized in that it comprises a stator (17) as defined in any one of the preceding claims. 12. Fan for a motor vehicle characterized in that it comprises a rotary electric machine (10) as defined in the preceding claim.