FR3085805A1 - INTERCONNECTOR COMPRISING MEANS FOR GUIDING PORTIONS OF CONDUCTORS - Google Patents

Abstract

The invention relates mainly to an interconnector (30) for the interconnection between conductors of a stator winding (24) of an electric machine, extending over an angular sector (α) around an axis X, the interconnector comprising means for guiding the winding conductors (36) adapted to direct first portions of said winding conductors (242) towards a control electronics.

Description

INTERCONNECTOR COMPRISING MEANS FOR GUIDING PORTIONS OF CONDUCTORS.

The invention relates to an interconnector comprising means for guiding portions of conductors towards electronics.

In a manner known per se, rotary electrical machines comprise a stator and a rotor secured to a shaft. The rotor can be integral with a driving and / or driven shaft and can belong to a rotating electrical machine in the form of an alternator, an electric motor, or a reversible machine capable of operating in both modes.

Furthermore, the stator is mounted in a casing configured to carry the shaft in rotation, for example by means of bearings. The stator comprises a body constituted by a stack of thin sheets forming a crown-shaped cylinder head, the inner face of which is provided with notches open towards the inside to receive a winding.

In a wavy type winding, the phase windings are each formed from at least one winding conductor, such as a continuous wire, covered with an insulating layer, in particular an enamel layer. Alternatively, the winding is obtained from winding conductors in the form of pins electrically connected to each other, for example by welding.

To obtain the desired electrical coupling of the machine, for example in a triangle or a star, first portions of the winding conductors must be connected to the control electronics, and second portions of the winding conductor must be connected electrically.

It is known to connect the first winding portions to the control electronics via an interconnector, and to use the interconnector to electrically connect the second portions of conductors to each other. In such solutions, many welds must be made. Furthermore, the conductor portions being quite fragile and entering into vibration, there is a significant risk of breakage of these first conductor portions between the winding and the electronics.

The present invention aims to effectively remedy these drawbacks by proposing an interconnector for the interconnection between conductors of a stator winding of an electric machine, extending over an angular sector around an axis, the interconnector comprising guide means. winding conductors adapted to direct first portions of said winding conductors towards control electronics.

Such an interconnector makes it possible both to ensure the interconnection function between the second portions of conductors to be interconnected and to guide the first portions of conductors to the control electronics, limiting the risk of rupture of these first portions of fragile conductors. The interconnector is notably judiciously positioned above the winding so as to limit the vibrations of the conductor portions, in particular at resonance. Furthermore, the use of such an interconnector makes it possible to limit the number of welds to be made.

According to one embodiment, the interconnector comprises at least one conductive element held in a housing, the guide means being holes drilled in the housing.

According to one embodiment, at least one of the holes has a shape suitable for inserting a portion of conductor with circular section and rectangular section therein.

According to one embodiment, the interconnector comprises at least one conductive element held in a housing, the guide means being formed by clips extending from the housing. This realization is easy to implement.

According to one embodiment, the guide means are angularly offset around the axis.

According to one embodiment, the interconnector also comprises electrically conductive tabs offset angularly around the axis, adapted to electrically connect second portions of conductors of a stator winding.

According to one embodiment, the guide means are angularly interposed with the electrically conductive tabs around the axis. This allows the interconnector to be adapted to the shape of the stator winding.

The invention also relates to a machine comprising a stator winding extending in a circumferential direction around the axis, an interconnector as previously described, in which the means for guiding the interconnector are arranged along the circumferential direction of the stator winding, directing first portions of said winding conductors towards control electronics. This minimizes the deviation of the conductor portions during assembly.

According to one embodiment, the interconnector comprises electrically conductive tabs offset angularly in the circumferential direction around the axis, the tabs electrically connecting between them second portions of conductors of the stator winding, at least one portion of winding conductor being fixed to a tab by laser welding.

According to one embodiment, each tab of the interconnector is connected to a portion of the winding conductor belonging to a separate phase of the winding. This makes it possible to achieve the neutral point or the triangle coupling of said stator winding.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figure 1 is a partial sectional view of a rotary electrical machine for carrying an interconnector according to the present invention;

Figure 2 is a perspective view of the stator carrying the interconnector according to the invention ensuring the coupling of the winding conductor portions;

Figure 3 is a perspective view of an interconnector having interconnecting tabs and guide elements, according to the invention;

Figure 4 is a perspective view of the conductive elements of the interconnector according to the present invention before molding a housing around;

Figure 5a is a top view of the interconnector illustrating a first embodiment of the guide means;

FIG. 5b illustrates a particular form of the first embodiment of the guide means;

Figure 6 is a top view of the interconnector illustrating a second embodiment of the guide means.

Identical, similar, or analogous items retain the same reference from one figure to another.

FIG. 1 represents a compact and polyphase rotary electrical machine 10, in particular for a motor vehicle. This rotating electrical machine converts mechanical energy into electrical energy, in alternator mode, and can operate in motor mode to transform electrical energy into mechanical energy. This rotary electric machine is, for example, an alternator or a reversible machine.

The rotary electrical machine comprises a casing 11. Inside this casing, it further comprises the shaft 12, the rotor 13 integral in rotation with the shaft and the stator 14 surrounding the rotor. The rotational movement of the rotor 12 takes place around an axis X, which is the axis of the machine. In the following description, the radial, ortho-radial and axial orientations are to be considered with respect to this axis X. In the following description, the rear part is the part of the machine comprising the electronics and the front part is the part of the machine on the pulley side.

In this example, the casing 11 comprises a front bearing 15 and a rear bearing 16 which are assembled together. These bearings are hollow in shape and each carry a respective ball bearing centrally for the rotational mounting of the shaft 12.

A pulley 17 is attached to a front end of the shaft 12, at the front bearing. This pulley 17 transmits the rotational movement to the shaft.

The rear end of the shaft 12 carries a collector 18. A brush holder 21 supplies the rotor via the collector and is connected to a voltage regulator (not shown) included in a rectifier bridge.

The front bearing 15 and the rear bearing 16 may further include openings 27 substantially lateral for the passage of air in order to allow the cooling of the rotary electric machine by air circulation generated by the rotation of a front fan 28 on the front face of the rotor, that is to say at the level of the front bearing and a rear fan 19 on the rear face of the rotor, that is to say at the level of the rear bearing.

In this exemplary embodiment, the stator 14 comprises a body in the form of a packet of sheets 23 provided with notches, for example of the semi-closed or open type, equipped with insulating notches for mounting a stator winding. 24. The stator body has an annular cylindrical shape with an axis X. The winding 24 passes through the notches of the body and forms a front bun 25 and a rear bun 26 on either side of the stator body 14.

The winding extends in a circumferential direction around the X axis along the body of the stator.

The winding 24 also extends radially between an internal winding periphery closer to the axis X and an external winding periphery closer to the bearing.

In this example, the rotor 13 is a claw rotor comprising two pole wheels. When the rotor 13 is magnetized and becomes an inductor rotor with the formation of North-South magnetic poles, an alternating induced current is created in the coil 24 of the stator 14 induced by the rotation of the shaft 12.

A rectifier bridge formed by electronic power modules (not shown) then transforms this alternating induced current generated by the machine into a direct current, in particular to supply the loads and consumers of the on-board network of the motor vehicle as well as to recharge its battery. . These modules or other power modules can also be ordered to inject current into the different phases of the electric machine when the latter is operating in motor mode.

The stator winding 24 is composed of a plurality of conductors forming the phases. More precisely, each phase comprises an end of electrical conductor forming an electrical neutral point 240, an end of electrical conductor forming a connection point of a phase output 242, electrically connected to the electronic power modules. The phase connection terminals are therefore formed by two ends of the conductor.

In what follows, stator circumference will be understood to mean a curve among the curves matching the average position of the stator winding. A stator circumference will for example be given by a circle centered on the X axis and passing through the ends of the conductors.

In what follows, the term angular sector will be understood to mean the angle defined along the stator winding, from the center of the machine, around the axis X, in a plane orthogonal to the axis of the machine.

Advantageously, as illustrated in FIG. 2, the ends of the conductor 240, 242 are therefore on the same stator circumference and extend along an angular sector of the stator 14. The angular difference between the ends of the phases to be connected to the neutral point 240 is constant along the angular sector in which the ends are situated, as shown in FIG. 2. In the same way the angular difference between the ends of the phases to be connected to the electronics 242 is constant the along the angular sector in which they are located.

The conductor ends each advantageously extend along the X axis of the machine.

Advantageously, each end of the conductor to be connected to the neutral point 240 is interposed between two ends to be connected to the electronics 242 along the circumferential direction of the stator winding.

In a first embodiment, the winding is a three-phase winding, the first portions of winding conductors 242 being the ends of each electrical conductor for the phase, to be connected to the electronics, and the second portions of winding conductors 240 being the ends of each electrical conductor for the phase, to be connected to the neutral point electrically.

In an electrical coupling of star type, the ends connected to the neutral point 240 are connected by means of an interconnector 30 visible in FIG. 2. Alternatively, in an electrical coupling of triangle type, the ends connected between the phases are connected by means an interconnector 30.

This interconnector 30 extends in the shape of an arc of a circle over an angular sector of angle a around the axis X above the front (or rear) chignon, that is to say in a plane orthogonal to the axis of the machine X. The interconnector 30 extends along a limited angular sector between 30 ° and 90 °, advantageously. The interconnector 30 advantageously follows the arc of the curvature of the front bun around the axis X.

The interconnector 30 positioned substantially between the inner and outer peripheries of the winding, can notably protrude radially from the stator winding.

The interconnector 30 advantageously comprises three legs 31, 32, 33, electrically conductive, angularly offset around the axis X. The legs 31, 32, 33 are angularly offset along the arc of the interconnector, advantageously following the curvature of the interconnector, as illustrated in FIG. 3. The legs are advantageously angularly close, that is to say separated by a small circumferential distance which advantageously corresponds to the distance separating the first ends of the conductor.

As illustrated in FIG. 3, each tab of the interconnector positioned radially between the axis of the machine and the bearing advantageously extends along the axis X. The tabs of the interconnector advantageously extend on the same side of the stator winding 24 as the ends of the conductors to be interconnected 240.

A conductive body 34 for example advantageously electrically connects the tabs together. The body 34 extends for example in an extension plane of the interconnector 30, which is advantageously transverse to the axis of the machine X, and the lugs 31, 32, 33 extend from the body of the interconnector 34. The legs extend, for example, along a first portion contained in the plane of the body, then an adjacent portion transverse to the previous portion and extending along the axis X, as illustrated in FIG. 4, by one of the two conductor elements illustrated. The legs thus have a bent shape. A conductive element is thus formed by said body 34 and the tabs 31, 32, 33.

Each lug has a radial end surface 300 illustrated in FIG. 3, advantageously carried by the lug portion extending along the axis X of the machine, that is to say the portion of the lug adjacent to the free end of the tab. The radial end surface 300 defines a connection surface for a first end of the conductor 240.

A housing is molded around the conductive element 35, thus forming the interconnector 30 illustrated in FIG. 3. The housing advantageously extends in the plane transverse to the axis of the machine X.

The ends to be connected to the electronics 242 are advantageously guided by guiding means 36 of the preceding interconnector 30, illustrated in FIG. 3.

The guide means are distributed along the arc of the interconnector, advantageously following the curvature of the interconnector. The guide means 36 are advantageously angularly close, that is to say separated by a small circumferential distance which advantageously corresponds to the distance separating the ends of the conductor to be guided towards the electronics 242. The guide means advantageously extend on the same side of the stator winding 24 as the ends of the conductors to be connected to the electronics 242.

The tabs to be welded to the ends of the conductor to be interconnected 31, 32, 33 and the guide means 36 are angularly inserted around the axis X, that is to say along the interconnector so as to respect the geometry of coil in which the conductor ends to be interconnected and the conductor ends to be electrically connected are also angularly offset around the X axis along the circumferential direction of the coil.

In the case of the winding described above, the tabs 32 and 33 are each interposed between two guide means 36, as illustrated in FIG. 3, and the tab 31 is adjacent to a guide means 36. By angularly traversing the interconnector in the clockwise follow one another the tab 31, a guide means 36, the tab 32, another guide means, the tab 33 and a last guide means.

The guide means are, in a first embodiment, illustrated in FIG. 5, holes drilled in the housing, along the axis of the machine for example, that is to say advantageously transverse to the direction of exit ends of conductors to be directed to the control electronics.

At least one of the holes has in particular a shape suitable for inserting a matrix conductor therein, the section of which is therefore variably circular and rectangular.

The hole for this has a shape as illustrated in Figure 5 with in particular a rounded part and a straight part.

The clearance between the wire and the hole is in particular the smallest possible in order to be able to completely block the conductor in the hole simply by adding a little varnish.

The guide means are, in a second embodiment illustrated in Figure 6, clips extending from the housing.

The clips extend, for example, in the housing extension plane, transverse to the X axis of the machine. The clips are thus advantageously transverse to the direction of exit of the ends of the conductors to be directed towards the control electronics. The clips, for example, came integrally with the housing.

The clips are, for example, in the form of a deformable jaw, suitable for inserting the ends of the conductor in force. As a variant, the clips are in the form of non-deformable jaws, the ends of the conductors being slid into the jaws during mounting of the interconnector on the winding.

In a variant of the first embodiment, the stator 14 has a three-phase double winding. The interconnector 30 then comprises six tabs 31, 32, 33 and 31 ’, 32’, 33 ’for connecting the two three-phase systems. The three legs 31, 32, 33 are electrically connected to each other and allow the first three-phase system to be connected and the three legs 31 ', 32', 33 'are electrically connected to each other, allow the second three-phase system to be connected, and are isolated. electrically from the three legs 31 32 ', 33'.

The tabs for connecting the two three-phase systems will advantageously be interposed, that is to say that two adjacent tabs of the interconnector 30 in the circumferential direction will not be electrically connected.

A conductive element 35 connects for example the legs 31, 32, 33 and a conductive element 35 ’connects the legs 31’, 32 ’, 33’. The two conductive elements 35 and 35 ’are arranged one above the other as illustrated in FIG. 4. A housing is molded around the two conductive elements to form the interconnector 30 illustrated in FIGS. 5 and 6.

The guide means 36 and 36 'of each of the two three-phase windings are interposed with the tabs of the two conductors so that two adjacent tabs for the two three-phase systems, for example 31, 31', are separated from the following two adjacent tabs for the two three-phase systems, for example 32, 32 ', by two adjacent guide means 36, 36' for each of the two conductor ends of each three-phase winding, to be connected to the electronics.

In order to establish the connections, the three ends to be interconnected 240 of the first three-phase system are electrically connected to the first system of legs 31, 32, 33, and the three ends to be interconnected 240 of the second three-phase system are electrically connected to the second system of legs 3T, 32 ', 33'. The three ends to be electrically connected 242 of the first three-phase system are guided towards the control electronics by the three guide means 36. The three ends to be electrically connected 242 of the second three-phase system are guided to the control electronics by the three means guide 36 '.

Without necessary deviation of the wire, the first ends of the conductor 240 each exit parallel and opposite a connection surface 300 of a tab to be fixed and each is directly connected to the connection surface 300 of the opposite tab. Similarly, each second conductor end 242 is mounted in the nearby guide means 36, without necessary deviation of the wire.

In a second embodiment not shown, the portions of winding conductors 240 to be interconnected are interconnection ends of the same phase of a winding to be brought back to the same potential, for example.

Each first end of the conductor 240 is advantageously fixed to the facing tab to which it must be connected, by laser welding. The soldering is carried out at the free end surface of the tab 301, and at an end surface to be welded from the end of the conductor. These end surfaces are advantageously substantially the same size, with a difference of around 20 percent.

In practice, the end of the conductor 240 will be cut beforehand, then a tool bends and maintains this end of the conductor to be welded resting on the support surface 300 of the tab.

The surfaces of the free ends 301 of the legs 31, 32, 33, 31 ', 32', 33 'will advantageously be substantially all contained in the same plane, for example perpendicular to the axis X, in order to simplify the welding process. .

The end surfaces to be welded are then also advantageously contained in this same plane, which will be the welding plane.

The weld plane therefore comprising both the surfaces to be welded of the ends of the conductors and the free ends 301 of the corresponding tabs, this makes it possible to simplify the sequence of welds by in particular not having to modify the height of the laser for firing.

The choice of two identical materials for the tab and the conductor portion 240 makes it possible to further improve the soldering, such as almost pure copper in particular.

The end of the conductor 240 to be welded will be stripped for example over a height along X of 4mm, advantageously 3mm, from the surface to be welded, and a length of lug of 4 mm along the axis X will advantageously exceed the plastic overmolding of the interconnector 30.

The conductor end 240 will thus advantageously be sufficiently stripped and the free end surface 301 of the tab sufficiently distant from the plastic of the interconnector 30 so that the heat generated by the laser shot near the welding point does not risk burn the conductor's enamel or the interconnector's plastic, which can generate gases and splashes of material. Such gases which can contaminate the weld and generate the appearance of bubbles inside and the projections of materials which can contaminate the weld in progress, the neighboring tabs, the stator and the tools are thus avoided as much as possible.

The axis of the laser performing the weld is used perpendicular to the weld plane, therefore along the X axis here typically.

We will use a bi-spot laser (firing in two points and not in only one), allowing to fire simultaneously on the two surfaces to be welded. This will allow in particular to weld despite a slight axial offset between the tab and the conductor end.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention from which one would not depart by replacing the various elements with any other equivalent.

Furthermore, the various features, variants, and / or embodiments of the present invention can be combined with one another in various combinations, insofar as they are not incompatible or mutually exclusive of one another.

Claims (10)

1. Interconnector (30) for the interconnection between conductors of a stator winding (24) of an electrical machine, extending over an angular sector (oc) around an axis X, the interconnector comprising guide means for winding conductors (36) adapted to direct first portions of said winding conductors (242) to control electronics. 2. Interconnector according to claim 1 comprising at least one conductive element held in a housing, the guide means (36) being holes drilled in the housing. 3. Interconnector according to claim 2 wherein at least one of the holes has a shape adapted to insert a portion of conductor with circular section and rectangular section. 4. Interconnector according to claim 1 comprising at least one conductive element held in a housing, the guide means (36) being formed by clips extending from the housing. 5. Interconnector according to one of the preceding claims, in which the guide means (36) are angularly offset around the axis X. 6. Interconnector according to one of the preceding claims also comprising electrically conductive tabs (31, 32, 33) angularly offset around the axis X, adapted to electrically connect between them second portions of conductors of a stator winding (240 ). 7. Interconnector according to claim 6 in which the guide means (36) are angularly interposed with the electrically conductive tabs (31, 32, 33) around the axis X. 8. Machine including: a stator winding (24) extending in a circumferential direction around the axis X, an interconnector (30) according to any one of claims 1 to 7, in which the guide means (36) of the interconnector ( 30) are arranged along the circumferential direction of the stator winding (24), directing first portions of said winding conductors (242) towards a control electronics. 9. Machine according to claim 8, wherein the interconnector comprises electrically conductive tabs (31, 32, 33) offset angularly in the circumferential direction around the axis X, the tabs electrically connecting second portions of conductors of the stator winding (240), at least a portion of winding conductor (240) being fixed to a tab by laser welding. 10. Machine according to claim 9 wherein each tab (31, 32, 33) of the interconnector (30) is connected to a portion of the winding conductor (240) belonging to a separate phase of the winding.