FR2808938A1 - Stator assembly for electrical alternator includes use of brazing alloy between stator winding segments, prior to pinching segments into connected position - Google Patents

Abstract

The stator (10) comprises windings formed from a series of U-shaped conductors. For each radial alignment (AR) of the contact ends (EC), a brazing alloy is radially interposed between the contact ends (EC). The radial alignment (AR) between two electrodes through which current is to flow are then pinched radially to complete the circuit. The stator (10) comprises stator windings formed from a series of U-shaped conductors which are inserted axially within axial notches formed in the stator. Each notch includes more than two conductors which are radially superposed, and which are connected together at their free contact ends (EC). For each radial alignment (AR) of the contact ends (EC), a brazing alloy is radially interposed between the contact ends (EC) to connect them electrically. The radial alignment (AR) between two electrodes through which current is to flow are then pinched radially to complete the circuit.

Description

<B> "Electrical connection method </ B> <B> of the conductors of a stator" </ B> The present invention relates to a conductive electrical connection method of a stator.

The invention relates more particularly to a method of electrically connecting the conductors of a rotating electric machine stator, of the type in which the stator comprises a cylindrical annular shaped body provided with a series of axial open slots, stator windings forming windings, each winding being associated with an electrical phase, of the type in which each winding is produced by means of a series of generally U-shaped conductors which are electrically connected to one another and each of which comprises two branches of generally axial orientation and a transverse connecting branch arranged on the side of an annular transverse face determined stator, each conductor having a substantially rectangular cross section whose width is greater than or equal to its thickness, of the type in which each axial leg of a U-shaped conductor received in a notch that is angularly offset relative to the notch which contains the other axial branch of this conductor, each notch receiving more than two axial branches of conductors are superimposed radially in the direction of the thickness, of the type in which the free end sections of the branches conductive axial elements are bent in a substantially circumferential direction at the notch exit so as to form radial alignments of contact ends for the electrical connection of the conductors, and of the type in which each winding of a phase comprises at least one electrical connection input and output electrical connection.

Electrical connection methods exist for electrically connecting the generally rectangular shaped and cross-section conductors of an alternator stator.

In particular, known methods for electrical connection by resistance brazing in which interposes a brazing alloy between the contact ends of two conductors to be electrically connected, then the two contact ends between two electrodes are clamped and circulated. a current for melting the alloy.

The disadvantage of this type of process is that it is necessary to carry out as many braze-welding sequences as there are pairs of contact ends to be connected electrically.

The invention aims to remedy this drawback.

For this purpose, the invention provides a method of the type described above, characterized in that it consists, for each radial alignment of contact ends, to perform the following operations - radially interpose a solder alloy between the contact ends electrically connected; and radially pinching the radial alignment between two electrodes through which an electric welding current is circulated. Thanks to the method according to the invention, it is possible to produce, at each electrical welding pulse, several electrical connections in a radial alignment of contact ends.

This type of method is particularly suitable for stators comprising more than two layers of axial branches of conductors per notch.

It is noted that the adjacent contact ends of a radial alignment for which no brazing alloy has been interposed are not welded together and can be separated later.

According to other characteristics of the invention - conductors are coated with a layer of insulating material, for example enamel, and the insulating material contacting ends are stripped which covers them, before interposing the alloy brazing ; when the method is of the type in which the stator body comprises three electrical phases each consisting of two stator windings, and of the type in which each notch receives four axial branches of different conductors so that each radial alignment comprises an external contact end. , external intermediate contact end, an inner intermediate contact end and an inner contact end, each phase comprises a radial input alignment, one contact end of which is electrically connected to the input connection of the phase and another of which contact end is electrically connected to a contact end of a consecutive radial output alignment of the phase, the output radial alignment having a contact end which is electrically connected to the output link of the phase; for each phase, the external intermediate contact end of the input alignment is electrically connected to the phase input link, the external contact end of the output alignment is electrically connected to the output connection of the phase, and the outer ends of contact input and output alignments are electrically connected together; for each input alignment, a brazing alloy is placed between the internal contact end and the internal intermediate end of contact, a brazing alloy is placed between the external intermediate contact end and an electrical connection wire towards phase input link, and a solder alloy is placed between the outer contact end and an electrical connecting wire to the outer contact end of the associated output alignment; for each output alignment, a brazing alloy is placed between the internal contact end and the internal intermediate contact end, and a brazing alloy is placed between the external contact end and the electrical connection wire towards the contact end. external contact end of the associated input alignment; and for each of the other radial alignments, or ordinary alignments, a brazing alloy is placed between the external end of contact and the external intermediate contact end, and a brazing alloy is placed between the internal intermediate end of contact and the internal end of contact; - Folding, in the opposite direction to the normal direction, each of the free end sections having the outer end contact an input alignment so that its outer end contact is superimposed radially against the outer end of contacting the associated output alignment, and such that said free end section replaces the corresponding electrical connection wire, and for each output alignment, an alloy solder is placed between the two superposed external contact ends; The method consists in successively carrying out the following operations: electrically connecting the ordinary radial alignments and the radial output alignments; radially moving away the contact ends so as to delimit, in each radial alignment, a radial space between internal and external intermediate intermediate contact ends; # insert axially in the radial space a common electrical connection bar adjacent to the outer intermediate end contact each input alignment; radially interpose a brazing alloy between the common electrical connection bar and the external intermediate contact end, between the internal contact end and the internal intermediate contact end of each input alignment, and between the external contact end and the associated electrical connection wire, if the free end section comprising the corresponding external contact end is not bent in the opposite direction; and # pinching radially each input alignment between two electrodes through which an electric welding current is circulated.

Other features and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the accompanying drawings in which - Figure 1 is a perspective view which schematically shows an alternator stator of motor vehicle ; - Figure 2 is a schematic cross-sectional view shows the arrangement of the conductors in an axial stator slot; - Figure 3 is an exploded perspective view which schematically shows a pair of adjacent conductors of the stator; FIG. 4 is a perspective view which schematically shows the pair of adjacent conductors of FIG. 3; - Figure 5 is a partial perspective view showing a stator portion and radial alignments of contact ends; - Figure 6 is a schematic view from above which illustrates the electrical connections between the different conductors of the stator; FIG. 7 is a diagram illustrating the interposition of the brazing alloy in a radial alignment of contact ends; - Figure 8 is a diagram similar to the previous one which illustrates the pinching of a radial alignment by welding electrodes; FIG. 9 is a diagram similar to that of FIG. 7 which illustrates welds made by the welding electrodes in a radial alignment; FIG. 10 is a view similar to that of FIG. 6, which illustrates a first step of the method according to the invention during which the electrical connections are made in ordinary alignments; FIG. 11 is a view similar to FIG. 6, which illustrates the second step of the method according to the invention during which the electrical connections of output alignments are made; - Figure 12 is a view similar to that of Figure 6 which illustrates formation of radial spaces in the radial alignments of contact ends.

In the following description, it will be arbitrarily defined and limited, with reference to Figure 1, an upper orientation and lower orientation along the axis A-A of the stator.

will first describe an alternator stator having conductors which are intended to be electrically connected to the method means according to the invention.

schematically represented in Figure 1 a motor vehicle alternator stator 10 which comprises a substantially cylindrical annular body 12 provided with axially emergent axial notches 14.

stator body 12 is conventionally constituted by an axial stack of sheets of steel plate in the form of a washer.

The stator body 12 comprises, for example, thirty six axial notches 14. The electrical conductors 16 are inserted axially into the notches 14 of the stator body 12.

stator 10 comprises for example seventy-two conductors 16.

As shown in FIG. 3, each conductor 16, generally U-shaped, comprises two branches B of substantially axial orientation which are received in the axial notches and a transverse connection branch 18 which is arranged on the annular lower transverse face 20 of the stator body 12.

As can be seen in FIG. 2, the conductors 16 are of rectangular section and here have a width f greater than their thickness e.

conductors 16 are coated with a layer of insulating material example of enamel.

Each notch 14 here receives four axial branches are superimposed radially in the direction of the thickness e. Axial branches B thus radially form an outer layer Cext, an external intermediate layer Ciext, an inner intermediate layer Ciint and an inner layer Cint.

inside each axial notch 14, a sheet 22 insulating material is interposed between the radial stack of axial branches the body 12 of the stator.

In the embodiment shown here, the conductors are arranged in pairs P of adjacent conductors 16.

represented such a pair P of conductors 16 in FIGS.

Each pair P of conductors 16 comprises an external conductor CRext of which a first axial branch B is inserted into the outer layer Cext of a first notch 14 and of which a second axial branch B is inserted into the inner intermediate layer Ciint of a second notch 14, and an internal conductor CRint having a first axial branch B is inserted in the outer intermediate layer Ciext of the first notch 14 and a second axial branch B is inserted into the inner layer Cint of the second notch notes that the first and the second notches 14 are notches 14 consecutive of the same electrical phase X, Y, Z, are separated here by two notches 14 receiving conductors belonging to two other electrical phases.

The free end sections 24 of the conductive B axial branches 16 are located on the side of the upper transverse face 26 of the stator body 12.

The free end sections 24 of the two axial branches of a conductor 16 are folded once, at the exit of notch 1 as can be seen in FIG.

This folding is performed generally around a bending axis of radial orientation, that is to say parallel to the width f perpendicular to the thickness e.

The arrows F in FIG. 2 indicate the folding direction of each free end section 24 of an axial branch B for this embodiment.

free end sections 24 of the intermediate layers Ciint, Ciext are folded here in the counter-clockwise direction whereas the free end sections 24 of the external Cext and internal Cint layers are folded here in the clockwise direction by considering the body 12 of stator seen from above.

The free end sections 24 folded have their free ends, or contact ends EC, which form radial alignments AR.

<B> There are as many radial alignments AR as axial notches 14, here thirty-six.

Each radial alignment AR has an external contact end ECext, an external intermediate contact end ECiext, an internal intermediate contact end ECiint and an internal contact end ECint.

In the embodiment shown here, the stator 10 has three electrical phases called X, Y, and Z.

Each phase X, Y, Z comprises twelve poles which are provided to cooperate with the twelve poles of a rotor (not shown) so that when the rotor rotates inside the stator 10, they produce a voltage induced in the conductors 16. stator windings ES of a phase X, Y, Z. Each phase X, Y, Z consists of two stator windings ES1, ES2 electrically connected in series and occupying the same slots 14.

Each winding ES1, ES2 is continuous and comprises twelve conductors 16 arranged in turns, or loops and electrically connected to form the twelve poles.

FIG. 6 shows the radial alignments AR of the contact ends EC of the stator 10 when the conductors 16 are electrically connected.

Each phase X, Y, Z comprises an input link 28 and an output link 30, as well as a serial link 32 which connects the two stator windings ES1, ES2 constituting the winding of the phase X, Z.

three phases X, Y, Z having the same type of connection 28, 30, we will now explain the modes of connection of a phase, for example phase X.

input link 28 of the X-phase electrically connected to the first stator winding ES1 the external intermediate contact end ECiext of a first radial alignment, or input alignment ARe.

The output link 30 of the X phase electrically connected to the second stator winding ES2 by the external intermediate contact end ECiext second radial alignment, or output alignment ARs, which follows the input alignment ARe.

The two stator windings ES1, ES2 of the phase X are electrically connected in series by the external contact ends ECext of the input alignment ARe and the output alignment example an electrical connection wire is welded by its free ends on each of the two external contact ends ECext.

Advantageously, as shown in FIG. 6, it is possible to dispense with the electric connection wire by folding, in the counterclockwise direction, the free end section 24 corresponding to the external contact end ECext of the input alignment, so that this external contact end Ecext, is adjacent radially to the external contact end ECext of the output alignment is then electrically connect these two outer ends ECext contact directly by welding.

The inner intermediate contact end ECiint and the inner contact end ECint of the input alignment ARe and the output alignment ARs are electrically connected together.

note that each electrical phase X, Y, Z electrically connected to the same input link 28, which is here a neutral terminal constituted by an electric wire, or neutral bar.

In this case, the neutral bar 28 is inserted axially between the external intermediate contact end ECiext and the internal intermediate contact end ECiint of each radial alignment AR.

neutral bar 28 has a substantially circumferential orientation and extends here from the input alignment ARe of the X phase to the input alignment ARe of the Z phase, passing the input alignment ARe of phase Y.

For each of the other radial alignments ARo, ordinary alignments, which are neither input alignments nor output alignments ARs, the external contact end ECext is electrically connected to the external intermediate contact end ECiext, and the end ECiint internal intermediate is electrically connected to the ECint internal contact end.

Preferably, at least one insulating material sheet 34 is interposed between the neutral bar 28 and the adjacent internal intermediate contact ends ECiint.

Similarly, at least one insulating material sheet 36 is interposed between the neutral bar 28 and the external intermediate contact ends ECext which are adjacent thereto and are not electrically connected thereto.

also interposes at least one sheet 38 of insulating material between the external intermediate contact end ECiext and the external contact end ECext of the output alignment ARs of each phase X, Z.

will now explain the operation of the electrical connection method according to the invention. Since the conductors 16 are covered with insulating enamel, the contact ends EC are stripped before the electrical connection is made.

performs the electrical connection operations after the free end sections 24 of the conductors have been shaped, ie after the folding operations have formed the radial AR alignments of contact ends EC.

principle of the electrical connection ends of a radial alignment AR by solder-brazing according to the invention shown in Figures 7 to 9.

There is shown here an ordinary radial alignment ARo in which the internal intermediate contact end ECiint is connected electrically by solder-brazing to the internal contact end ECint the external intermediate end of contact ECiext to the external contact end ECext. .

 brazing of each radial alignment AR can be divided two successive operations.

The first operation, which is shown in FIG. 7, consists in radially interposing a brazing alloy 40 between the contact ends EC to be electrically connected.

second operation, which is shown in Figure 8, is to radially pinch the radial alignment AR between two electrodes 42 through which is circulated a welding electric current.

As shown in FIG. 9, a solder 44 is obtained, where the brazing alloy 40 has been interposed, which makes the electrical connection of the corresponding contact ends EC.

Electrical connection mode is used in the method according to the invention.

The first step of the process, which is shown in FIG. 10, consists in making the electrical connections in the ordinary alignments ARo.

For each ordinary alignment ARo, a solder alloy 40 is therefore interposed between the external contact end ECext and the external intermediate contact end ECiext, between the internal intermediate contact end ECiint and the internal contact end ECint, and then radially clamping each ordinary alignment ARo between two electrodes 42 through which electrical welding current is circulated.

Thus, at each pulse of electric welding current, two welds 44, thus two electrical connections, are produced in each of the ordinary alignments Aro, ie a weld between the external contact end ECext and the external intermediate end of contact. ECiext, and a weld between the inner contact intermediate end ECiint and the inner contact end ECint.

A second step of the method, which is shown in Figure 11, consists of making the electrical connections in the ARs output alignments.

For each output alignment ARs, a brazing alloy is interposed between the internal intermediate contact end ECiint and the internal contact end ECint, and between the two radially adjacent external contact ends ECext, and then an electric current is circulated. welding in the same way as for ordinary ARo alignments.

Thus, at each pulse of electric welding current, two electrical connections are made in the output alignment Ars, ie one between the internal intermediate contact end ECiint and the internal contact end ECint, and the other between the two radially adjacent outer contact ends ECext.

A third step of the method, which is shown in FIGS. 12 6, consists in making the electrical connections in the input aligners ARe.

It is first necessary to form a radial space Esp between the external intermediate contact end ECiext and the inner intermediate contact end ECiint of each radial alignment AR, at least since the input alignment ARe of the phase X up to the input alignment ARe of the phase Z, passing through the input alignment of the phase Y, in order to axially insert the neutral bar according to the means used to form the radial space Esp, It may be advantageous to form a radial space Esp in all radial alignments AR, as shown in FIG. 12. It is noted in particular that the radial space Esp allows to separate, in the ordinary alignments ARo, the two pairs of EC contact ends which are electrically connected welding, so that each pair is electrically isolated compared to the other pair.

When the radial space Esp is formed, axial bar 28 is inserted axially and, in each input alignment ARe, a brazing alloy 40 is interposed radially between the internal intermediate contact end ECiint and the internal contact end. ECint, and between the neutral bar 28 and the internal intermediate contact end ECiint, then a welding electric current is circulated in the same manner as for the ordinary alignments ARo.

Thus, at each pulse of electric welding current, two electrical connections are made in the input alignment ARe: between the internal intermediate contact end ECiint and the internal contact end ECint, and the other between the bar of neutral 28 and the external intermediate contact end ECiext.

stator 10 obtained by the implementation of the method according to the invention is shown in FIG.

Of course, the method according to the invention is applicable to stators comprising conductors arranged differently and in which the electrical connection diagrams are different from those of the embodiment described and shown here.

Claims (1)

<U> CLAIMS </ U> A method of electrical connection of the conductors (1 of a stator (10) of rotating electrical machine, of the type in which the stator comprises a body (12) of cylindrical annular shape provided with a series of open axial notches (14), stator windings (ES1, ES2) forming coils, each winding being associated with an electrical phase (X, Y, Z) of the type in which each winding (ES1, ES2) is realized at means of a series generally U-shaped conductors (16) which are electrically connected to each other and each of which comprises two branches of generally axial orientation and a transverse connecting branch (18) arranged on the side of a given annular transverse face (20) of the stator (10), each conductor (16) having a substantially rectangular cross section whose width (@ is greater than or equal to its thickness (e), of the type in which each axial branch (B) of a cone U-shaped duct (16) is received in a notch (14) which is angularly offset relative to the notch (14) and contains the other axial leg (B) of this conductor (16), each notch (14) receiving more two axial branches (B) conductors (16) which are superimposed radially in the thickness direction (e), of the type in which the free end sections (24) of the axial branches (B) of conductors (16) are folded in a substantially circumferential orientation at the notch exit (14) to form radial contact end alignments (AR) for the electrical connection of the conductors (16), and type in which each winding of a phase (X, Y, Z) comprises at least an electrical input connection (28) and an electrical output connection (30), characterized in that it consists, for each radial alignment (AR) of contact ends ( EC), to carry out the following operations to interpose radially a brazing alloy e (40) between the contact ends (EC) to be electrically connected; and radially pinching the radial alignment (AR) between two electrodes (42) through which an electric welding current is circulated. 2. Method according to the preceding claim, characterized in that the conductors (16) are coated with a layer of insulating material, for example enamel, and in that the denuded contact ends (EC) of the insulating material which covers them, before interposing the brazing alloy (40). 3. Method according to any one of the preceding claims, of the type in which the body (12) of the stator comprises three electrical phases (X, Y, Z) each consisting of two stator windings (ES1, ES2), and of the type in which each notch 4) receives four axial branches (B) of conductors (16), so that each radial alignment (AR) has an external contact end (ECext), an external contact end (ECiext), an internal intermediate end of contact (ECiint) and an internal contact end (ECint), characterized in that each phase (X, Y, Z) comprises an input radial alignment (ARe) having a contact end (ECiext) electrically connected to the connection d input (28) of the phase (X, Z) and of which another contact end (ECext) is electrically connected to a contact end (ECext) of a consecutive radial output alignment (ARs) of the phase (X , Y , Z), the radial output alignment (ARs) having a contact end (ECiext) which is electrically connected to the output connection (30) of the phase (X, 4). The method according to the preceding claim, characterized in that for each phase (X, Y, Z), the external intermediate contact end (ECiext) of the input alignment (ARe) electrically connected to the input link (28) of the phase Y, Z), the external intermediate contact end (ECiext) of the output alignment (ARs) is electrically connected to the output link (30) of the phase Y, Z), and the external contact ends (ECext) of the alignments d Input (ARe) and output (ARs) are electrically connected together. 5. Method according to the preceding claim, characterized in that - for each input alignment (ARe) is placed a solder alloy (40) between the inner contact end (ECint) and the internal intermediate end contact (ECiint), a brazing alloy (40) is placed between the external intermediate contact end (ECiext) and an electrical connection wire (28) of the (X, Y, Z) phase, and placing a solder alloy (40) between the external contact end (ECext) and an electrical connection wire towards the external contact end (ECext) of the associated output alignment (ARs); for each output alignment (ARs), a brazing alloy (40) is placed between the internal contact end (ECint) and the internal intermediate contact end (ECiint), and a solder alloy (40) is placed thereon between the external contact end (ECext) and the electrical connection wire towards the external contact end (ECext) of the associated input alignment (ARe); and for each of the other radial alignments, or ordinary alignments (ARo), a brazing alloy (40) is placed between the external contact end (ECext) and the external intermediate contact end (ECiext), and a brazing alloy (40) between the inner intermediate contact end (ECiint) and the inner contact end (ECint). 6. Method according to the preceding claim, characterized in that one folds, in the opposite direction to the normal direction, each of the free end sections (24) having the outer end of contact (ECext) of an alignment. input (ARe) so that its external contact end (ECext) is superimposed radially against the external contact end (ECext) of the associated output alignment (ARs), and so that said free end section ( 24) replaces the corresponding electrical connection wire, in that, for each output alignment (ARs), a brazing alloy (40) is placed between the two superposed external contact ends (ECext). 7. Method according to any one of claims 3 to 6, characterized in that it consists in successively performing the following operations - electrically connect the ordinary radial alignments (ARo) and the radial output alignments (ARs); radially moving away the contact ends (ECiint, ECiext) so as to delimit, in each radial alignment (AR), a radial space (Esp) between the internal intermediate contact (ECiint) and external intermediate (ECiext) ends; axially inserting into the radial space (Esp) a common electrical connection bar (28) adjacent to the external intermediate contact end (ECiext) of each input alignment (ARe); radially interposing a solder alloy (40) between common electrical connection bar (28) and the external intermediate contact end (ECiext), between the internal contact end (ECint) the internal intermediate contact end (ECiint) each input alignment (ARe), and between the external contact end (ECext) and the associated electrical connection wire, if the free end section (24) having the corresponding external contact end (ECext) is not not folded in the opposite direction; and radially clamping each input alignment (ARe) between two electrodes (42) through which an electric welding current is circulated.