FR2928790A1 - Rotor coil winding method for e.g. alterno-starter, in motor vehicle, involves winding wire around axle of coil to form radial line after radial line meshing such that portion of wire has shape of spiral in plane perpendicular to axle - Google Patents

Abstract

The method involves winding a wire (35) of a coil around an axle of the coil so as to form a radial line after radial line meshing such that a continuous portion of the wire corresponding to a radial line has a shape of spiral (S2) in a plane perpendicular to the axle. The portion of the wire is not wound from exterior towards interior, and comprises an internal end and an external end, where the coil is formed around an electrically insulating support. An independent claim is also included for a rotor of an electrical rotating machine.

Description

The present invention relates to a method of winding a winding of the rotor of a rotating electrical machine such as an alternator or an alternator-starter and a device for implementing the method and the product. obtained by the process. The rotors of the rotating electrical machines have a winding or excitation winding which comprises at least one spirally wound continuous wire, the turns of which are stacked on top of one another. Seen in a section plane passing through the axis of the rotor, this stack of winding turns constitutes a mesh of radial and axial lines. In the remainder of this presentation, use is made of this representation and the associated vocabulary. In particular, the terms mesh, radial line and axial line are used with reference to this representation. Winding of the winding is carried out layer by layer, that is to say axial line after axial line. A first layer of wire covers the core of the coil so as to form a first axial line, then a second layer of wire covers the first layer and so on. Each wire layer constitutes a helical winding in which the wire winds at an angle to the axis of the rotor which is opposite to that of the previous layer, thus leaving gaps between the wires of the different layers. These spaces degrade the filling rate of the winding. The overall thermal conductivity of the coil is much lower than that of pure copper not only because of the insulating resin that protects the surface of the wires, but also because of the aforementioned spaces between the winding wires. This adversely affects the cooling of the winding, which limits the permissible electric current in the wire of such a winding and therefore the power of the machine.

The object of the invention is to provide a winding method which improves the filling rate of the winding in the overall volume that it occupies. The method according to the invention is a method of winding a winding of the rotor of a rotating electrical machine, wherein: the winding comprises at least one wire and an axis about which said wire is wound in at least one determined direction of rotation, sections of the wire in a half-plane passing through the axis of the winding are juxtaposed at each turn next to one another, axially and radially to constitute in said half-plane a mesh of axial lines. In this method, the wire is wound around the axis of the winding, so as to form the radial line mesh after radial line, so that the continuous portion of the wire which corresponds to a radial line has substantially the shape of a spiral in a plane substantially perpendicular to said axis. Thanks to these arrangements, the portion of the winding wire which constitutes a radial line is wound round after turn in a continuous spiral 20 with little lost space, and the radial lines juxtapose axially next to one another with as little lost space. Thus, the spaces between the wires are very small, and the filling rate of the winding is improved. In various embodiments of the method of winding the rotor winding of a rotary electric machine according to the invention, one of the following arrangements may be furthermore used in isolation or in combination.

In embodiments, the coil comprises an inner part of the axis side and an outer part of the opposite side of the axis, and: the portion of the wire corresponding to a radial line n is wound from the outside towards inside, the portion of the wire corresponding to the radial line n + 1 adjacent to the radial line n is wound from the inside to the outside; and, the portions of the wire corresponding to the radial lines n and n + 1 are wound around the axis in the same direction of rotation, where n is an index designating the rank of the radial lines along the axis of the rotor. In the first embodiment, the portion of the wire corresponding to the radial line n and the portion of the wire corresponding to the radial line n + 1 are continuous, that is to say without interruption of the wire. It is thus possible to wind two consecutive radial lines without the need to cut the wire used to carry out the winding. This avoids having to weld together the two portions of wire corresponding to these two radial lines, respectively, the welding being necessary to establish the electrical continuity of the coil. In other words, the mesh is formed by pair of radial lines with a continuous portion of the winding wire, one radial line after the other within the same pair. In this embodiment: the portion of the wire corresponding to the convergent spiral radial line n is wound on a first tool of substantially conical shape, so that the portion of the wire corresponding to each tower is placed axially relative to the portion of the wire corresponding to the preceding turn at an axial distance greater than an axial width of the wire, - the first tool is withdrawn and the portions of the wire corresponding respectively to all the portions of the wire corresponding to the radial line n are withdrawn so that they are in the same foreground substantially perpendicular to the axis; In this embodiment, the radial line n + 1 may be made in the following manner: the portion of the wire corresponding to the radial line n + 1 in a divergent spiral is wound on a second tool of substantially conical shape, so that the portion of the wire corresponding to each turn is placed axially with respect to the portion of the wire corresponding to the preceding turn at an axial distance greater than the axial width of the wire, - the second tool is removed and the portions of the wire corresponding respectively to all the portions of the wire corresponding to the radial line n + 1 so that they are in the same second plane substantially perpendicular to the axis and at an axial distance from the first plane substantially equal to said axial width of the wire. These first and second tools, used in the manner defined above, provide support for winding the winding wire. In a second embodiment, the coil comprises an inner portion of the axis side and an outer portion of the opposite side of the axis, and wherein: the portion of the wire corresponding to a radial line is wound around of the axis in a first direction of rotation, and the portion of the wire corresponding to a radial line n + 1 adjacent to the radial line n is wound around the axis in a second direction of rotation opposite to said first direction of rotation. rotation, and - the portion of the wire corresponding to the radial line n and the portion of the wire corresponding to the radial line n + 1 are wound from the inside to the outside, where n is an index designating the rank of the radial lines following axis. In this embodiment - the portion of the wire corresponding to each radial line comprises an inner end and an outer end, and - the inner end of the portion of the wire corresponding to the radial line n is electrically connected to the inner end of the portion of the wire corresponding to the radial line n-1 by a first connecting means, and the outer end of the portion of the wire corresponding to the radial line n is electrically connected to the outer end of the portion of the corresponding wire at the radial line n + 1 by a second connection means. In this embodiment - the first connection means is a substantially rectilinear form of connection bar comprising a succession of conductive pads and alternating insulating portions, said connection strip being positioned radially in contact with all the inner ends of the portions of the wire. corresponding to the radial lines of the coil so that the successive internal ends of the portions of the wire corresponding to radial lines n and n-1 are soldered on the same pad of the connection strip; and, the second connection means is a weld. In this embodiment, the winding is made around a support section in the half-plane passing through the substantially U-shaped axis, and with side walls in planes substantially perpendicular to the axis and carried by the lateral branches of the U, and a bottom enveloping said axis and carried by the base of the U; and, the connection strip is locked on said bottom of the support, either by fixing or by insertion into a groove.

In a third embodiment, the winding is carried out continuously with a single wire. The wire is wound continuously from one side of the coil from the outside to the inside radial line by radial line and from the inside to the outside and so on until the other end of the coil.

In this embodiment, the winding is made by two concentric tools movable relative to each other in rotation and in translation. The rotation makes it possible to wind the wire from the inside to the outside or from the inside to the outside, while the translation makes it possible to pass from one radial line to the other.

In some of the embodiments, the portion of the wire corresponding to the radial line n has a number of turns different from the number of turns of the portion of the wire corresponding to the adjacent radial line n + 1. In some embodiments, the coil has a barrel-shaped external profile. In some embodiments, the winding wire has a substantially rectangular section. The invention also relates to a rotating electrical machine rotor, comprising a rotor axis and at least one coil comprising a wire wound around said rotor axis, wherein said wire comprises continuous portions, spirally wound each in a plane substantially perpendicular to said rotor axis. In one embodiment of the rotor of the invention, the winding comprises axially a first side and a second side opposite to said first side, and the rotor comprises a rotor shaft around which said winding is mounted. The rotor comprises: - on the first side of the winding, a first slip ring mounted on the rotor shaft and electrically connected to a first winding supply terminal, and - on the second side of the winding, a second slip ring mounted on the rotor shaft and electrically connected to a second power supply terminal of the winding, the first and second slip rings being for supplying the winding with electric current. In one embodiment of the rotor of the invention, the wire has a substantially rectangular section. The invention also relates to an alternator comprising a rotor and a stator mounted around said rotor, together forming an electric machine adapted to provide an electric current when the rotor is rotated about the rotor axis. The invention also relates to an alternator / starter comprising a rotor and a stator mounted around said rotor, together forming an electric machine adapted either to supply an electric current when the rotor is rotated about the rotor axis, either to rotate the rotor around the rotor axis when the alternator-starter is supplied with electric current. The invention will be better understood on reading the following description given solely by way of example and with reference to the appended drawings, in which: FIG. 1 is a longitudinal sectional view showing a rotor of an alternator of the state of the art; - Figure 2 is a longitudinal sectional view of a winding of a rotor of the state of the art; FIG. 3 is a view in longitudinal section of a winding obtained by a winding method according to a first embodiment of the invention; Figure 4 is a cross-sectional view along the direction IV-IV of Figure 3; - Figure 5 is a cross-sectional view along the direction V-V of Figure 3; FIG. 6 is a view in axial section of a winding obtained by a winding method according to a second embodiment of the invention; FIG. 7 is a view of the device allowing the implementation of the method of winding according to the second embodiment of the invention; FIG. 8 is a view in axial section of a winding obtained by a winding method according to a third embodiment of the invention; FIG. 9 is a view of the device allowing the implementation of the method of winding according to the third embodiment of the invention; Figure 9a is a view of a variant of the device of Figure 9; Figure 10 is a side view of the second tool of the device of Figure 9; Figure 10a is a side view of the second tool of the device of Figure 9a; - Figure 11 is a longitudinal sectional view showing a rotor of an alternator comprising a winding obtained by a winding method according to any of the embodiments of the invention.

In the remainder of the description, similar, similar or identical elements will be designated by the same number with reference to the appended drawings. The winding of a rotor comprises at least one axis of symmetry, corresponding to the axis of the rotor concerned. In the present description, axial directions and radial directions are denoted as directions indicated by the arrows "A" and "R", respectively, of FIG. 1. A tangential direction will be perpendicular to these two directions, and therefore perpendicular to the two directions. The directions of the longitudinal sectional plane of FIG. 1. Another element which is located on the axis side is also referred to as an inner element, and an element which is on the furthest side to the axis is called an outer element. FIG. 1 represents a rotor 12 of a known rotating electrical machine, such as a polyphase type alternator for a motor vehicle with a heat engine. Of course the alternator can also be reversible and consist of an alternator-starter that can operate in alternator mode or electric motor mode, in particular to start the engine of the vehicle.

This machine comprises a rotor 12 integral in rotation with a central shaft 14, called a rotor shaft, and a stator (not shown) which surrounds the rotor. The rotor 12 is made in the example shown in the form of a claw rotor comprising two pole wheels 20, 22, here axially juxtaposed and each having a transverse flange 24 of annular shape, provided at its outer periphery with claws 26 s extending substantially axially. Each claw 26 has a rooting portion 28 of transverse orientation in the plane of the flange 24 concerned. This rooting portion 28 is extended at its outer periphery by a longitudinal portion 30 of generally axial orientation having a generally trapezoidal or triangular section. An annular gap exists between the outer peripheral face 31 of the longitudinal portions 30 and the inner periphery of the stator body. The longitudinal portions of each of the pole wheels 20, 22 are directed axially towards the flange 24 of the other pole wheel 20, 22, the longitudinal portion 30 of a pole wheel 20, 22 penetrating the space between two longitudinal portions 30 of the other pole wheel 20, 22. Thus, the longitudinal portions 30 of the pole wheels 20, 22 are imbricated. An excitation coil 34 is implanted axially between the flanges 24 of the pole wheels 20, 22 on the one hand, and the inner faces of the longitudinal parts 30 on the other hand. It is carried by a rotor portion 12 in the form of a cylindrical annular core 36 coaxial with the shaft 14, which comprises a central bore 37. The core 36 here consists of two axially distinct sections each of which is made from material with a pole wheel 20, 22, associated, as shown in Figure 1. According to a variant not shown, the annular core 36 may consist of a single piece and it is distinct from the pole wheels 20, 22 which are then Arranged axially on either side of the core 36. In the rest of the description, the term winding without a qualifier must be understood as designating the excitation winding 34. The winding 34 is therefore implanted in the defined space. radially by the inner face of the claws 26 of the pole wheels 20, 22 and the outer side of the core 36.

The pole wheels 20, 22 and the core 36 are preferably of ferromagnetic material and are coaxially traversed by the rotor shaft 14. For this purpose, each pole wheel 20, 22 comprises a central bore 38 which passes axially through the flange. 24 and extends the bore 37 of the part of the core 36 concerned. According to a variant not shown, when the core 36 is in one part, the winding wire 34 is wound on an insulating element fixed on the core 36 and is shaped to avoid contact with the flanges 24 and the longitudinal portions 30 of the wheels polar 20, 22.

When the excitation winding 34 is activated, that is to say supplied by an inductive electric current, the pole wheels 20, 22 and the core 36 which is thus made of ferromagnetic material, are magnetized. The rotor 12 acts as an inductor, with the formation of magnetic poles of alternating polarity, at each of the longitudinal portions 30 of the claws 26 of the pole wheels 20, 22. When the shaft 14 rotates, this inductor rotor 12 creates a current induced, which is an alternating current, in windings of the stator of the rotating machine incorporating it.

The shaft 14 of the rotor 12 carries at its rear end slip rings connected by wire bonds (not shown) at the ends of the excitation coil 34 of the rotor 12. These rings receive the inductor current. In a known manner, the shaft 14 has sections 16 for driving a non-smooth radial section, which here are knurled sections (here with ridges), as can be seen in FIG. 1, for fixing and driving the pole wheels 20, 22 and the core 36. The pole wheels 20, 22 and the core 36 are thus mounted by force fitting on the shaft 14. The latter, being made of a harder material and having grooves, size grooves in the central bore of the pole wheels 20, 22 and in the core 36 when forced fitting. FIG. 2 shows a view in longitudinal section of a winding 34 of the prior art, the wire 35 of which is wound on a support 33 which is substantially axisymmetric about a support axis 32 and is mounted, preferably by force , on the outer periphery of the core 36. The support 33 is made of electrically insulating material. This support 33 is here of longitudinal section generally U-shaped in each half-plane defined by the axis 32, with side walls 33a to isolate the coil 34 flanges 24, wheels 20, 22 and rooting sections 28, and a bottom 33b to isolate the coil 34 of the core 36. These side walls 33a are in planes substantially perpendicular to the support axis 32. The bottom 33b forms a cylinder whose axis coincides with the support axis 32.

The wire 35, made of electrically conductive material such as copper, is here of generally circular section. This facilitates the method of winding the wire 35 on the support 33. The method of winding the wire 35 begins with the approach of an initial strand 35a in a substantially axial direction, so as to pass through one of the side walls 33a of the support 33. This initial strand 35a is also positioned in radial proximity to the bottom 33b. The wire 35 is then bent to have a substantially tangential direction to the bottom 33b cylindrical. The support 33 is then rotated, at the same time as a wire guide moves in a first axial direction. The wire 35 forms, at each turn of the support 33, a substantially helical turn which is positioned axially offset with respect to the preceding one, each strand of wire being inclined in a first direction with respect to the axis 32. A first layer winding 34 is thus produced along a first axial line 39.1, that is to say in such a way that sections of each turn in the plane AR of FIG. 2 are juxtaposed at each turn next to one another, axially in a first axial line 39.1 parallel to the axis 32. When the wire 35 reaches the other of the side walls 33a of the support 33, the wire guide is caused to move in the opposite axial direction. The wire 35 then forms, at each turn of the support 33 (which continues to rotate in the same direction of rotation), a substantially helical coil with a wire strand inclined on the axis 32 in a direction opposite to the first direction above. . A second layer of the coil 34 is thus produced, along a second axial line 39.2, parallel to the axis 32. Other layers of the coil are then produced in the same way, one above the other, with each time reversal of the direction of axial displacement of the wire guide.

The coil 34 is thus produced layer by layer, that is to say axial line after axial line, each layer having turns inclined on the direction of the axis 32 in a direction opposite to that of the previous layer, generating spaces that degrade the filling rate of the coil 34 and therefore its thermal conductivity.

According to a first embodiment of the invention shown in Figure 3, the coil 34 is made with a wire 35 of substantially rectangular shape or section, and preferably having an axial width greater than its radial height to facilitate the winding process of the wire 35 on the support 33. But the shape of the son could also be substantially round or oval shape. The support 33 further comprises on its bottom 33b and in an axial direction of said support, a connection strip 40, consisting for example of a succession of pellets 41, of electrically conductive material, and portions 42, of electrically insulating material, alternating. The terminal strip 40 may be disposed in a bottom groove 33b of the support 33. The method of winding the wire 35 is described below by each of its steps.

One end of the wire 35 is secured, by making electrical contact, with a first chip 41.1 of the connecting strip 40, for example by welding, thus forming an inner end of the wire. The support 33 is then rotated in a first direction of rotation R1, forming at each turn a turn which is positioned radially above the preceding one, to form turn after turn a spiral S1 in a plane substantially perpendicular to the axis of 32. The spiral S1 is thus produced along a first radial line 49.1, that is to say such that a section of a turn in the plane of FIG. 3 is positioned radially offset towards the outside the previous section, according to a first radial line 49.1. FIG. 4 is a cross-sectional view of the portion of the wire corresponding to the spiral S1, for which a single turn has been shown, the inner end of said spiral S1 being welded to the first patch 41. 1 of the bar of FIG. connection 40. The first direction of rotation of the support 33 to form the spiral S1 is the direction referenced R1. This sense is for example anti-trigonometric. When the wire 35 has made a predetermined number N1 of turns, a value not necessarily entire, but greater than 1, it is secured, for example by gluing on an outer face of the wire of the previous round; then the wire 35 is severed, to form an outer, free end, on the spiral S1 and a new end of the wire 35. In the case of the first spiral S1, a first power terminal 43 may be soldered to said outer end . In other cases, said outer end is in electrical contact with an outer end of the same type of the previous spiral Sn-1. The support 33 is then displaced axially by a distance corresponding to the axial width of the section of the wire 35. The new end of the wire 35 is secured by providing electrical contact with the first chip 41.1 in the same manner as above. , thus forming a new inner end of the wire. The support 33 is then rotated in a second direction of rotation R2 opposite the first direction of rotation R1. The wire 35 forms a spiral S2 along a second radial line 49.2 of FIG. 3. FIG. 5 is a cross-sectional view of the portion of the wire of the spiral S2, for which a single turn has been shown, the end inner of said spiral S2 being welded to the first chip 41.1 of the connecting bar 40. The second direction of rotation of the support 33 to form the spiral S2 is the direction referenced R2. This sense is then trigonometric, in the example. When the wire 35 has made a predetermined number N2 of turns, not necessarily equal to N1, it is secured in the same way as for the spiral S1 (for example by gluing); then the wire 35 is severed, to form an outer end, free and put on hold 20 to be brought into contact with the next spiral. In the case of a last turn of the coil 34, a second power terminal 44 may be soldered to this external end, and the method of winding the wire 35 is completed. In other cases of an intermediate spiral winding 34, this outer end will be in electrical contact with an outer end of the wire of the next spiral Sn + 1, for example by welding. The support is then displaced axially by an axial distance corresponding to the axial width of the section of the wire 35. The method of winding the wire 35 continues to achieve the following spirals. A spiral Sn, where n is odd, is made in the same way as for the spiral S1, that is to say with a first direction of rotation R1 of the support 33. A spiral Sn, where n is even, is realized in the same way as for the spiral S2, that is to say with a second direction of rotation R2 of the support 33. It will be understood that once all the spirals Sn winding brought into electrical contact by the connection strip 40 and by the outer ends, the coil 34 is electrically continuous from the first power supply terminal 43 to the second power supply terminal 44. In addition, by superimposing the spiral S1 of FIG. 4 to the spiral S2 of FIG. it will be understood that when the winding is powered by an electric current, the electric current can travel through the wire portions of this winding by rotating about the axis 32 always in one and only direction regardless of the direction of rotation R1 or R2 of the winding process. Each spiral generates an individual electromagnetic field in the core 36, which are added constructively to generate a global electromagnetic field for magnetizing the core 36. In this way, as shown in FIG. 3, a winding 34 is produced with a number M of radial lines, even, so that first and second supply terminals 43, 44 are disposed outside near each of the side walls 33a. However, it is also possible to make a winding 34 with an odd number of spirals and radial lines and / or supply terminals arranged outside or inside.

It is understood that the successive spirals of the coil 34 are electrically connected to each other, alternatively, either by their inner ends on a wafer 41 of the terminal strip 40, or by their outer ends. In other words, the portion of the wire 35 corresponding to a radial line n (spiral Sn) is connected on one internal side to the portion of the wire 35 corresponding to the previous radial line n-1 (spiral Sn-1) inside. of the coil 34 by the pellets 41, and is connected on the other external side of said portion of the wire 35 to the portion of the wire 35 corresponding to the next radial line n + 1 (spiral Sn + 1) outside the winding 34, by the outer ends of said spirals. As will be understood, the letter n is an integer index which designates the rank of the radial line in the series of radial lines, adjacent axially, which form the mesh. In addition, if each spiral comprises N turns or turns, and the coil 34 made has M spirals or radial lines, the coil 34 generally comprises MxN turns or turns.

Optionally, it is possible to produce a winding 34, whose adjacent spirals do not have the same number of turns, and in particular a number of incremented turn of a turn or decremented by one turn, for example by adding a trigger guard (no shown) of connection secured to each outer end of each spiral, for example by welding. In particular, it is thus possible to achieve a coil 34 whose radial or spiral lines located in a central zone with respect to each of the side walls 33a have a greater number of turns than the radial or spiral lines located near said side walls 33a. The coil 34 thus produced can thus have a barrel profile. With this shape, it is possible to fill more completely the space between the longitudinal parts 30 of trapezoidal shape of Figure 1, and in particular the space usually left free between the coil 34 of Figure 1 and said longitudinal parts 30 of claws 26. According to a second embodiment of the invention, the winding 34 is made by pair of radial lines n, n + 1 or spirals Sn, Sn + 1, continuously without cutting the wire 35, and more particularly without forming internal ends. Consequently, the winding 34 of this embodiment of the invention does not require a connection strip 40 or a welding of the internal ends, which makes it possible to save space radially and further improves the filling rate of the coil 34. This solution simplifies the implementation of connections that are all outside. As shown in FIG. 6 similar to FIG. 3 of the first embodiment, a turn or portion of internal turn 45.1 makes it possible to pass continuously from a first radial line 49.1 (spiral Si) to the next radial line 49.2 (FIG. spiral S2). To make such a pair of continuous spirals, the portion of the wire corresponding to the radial line 49.1 is wound by a method described later from the outside to the inside, the rotation on an inner turn 45.1 allows the offset of the wire of an axial width of the wire 35 of the radial line 49.1 to the radial line 49.2, and the portion of the wire of the radial line 49.2 is wound from the inside to the outside. The portions of the wire corresponding to the two radial lines 49.1 and 49.2 are wound around the axis 32 in one and the same direction of rotation, unlike the method for producing the first embodiment. Nevertheless, it is understood that, once they are connected together, by welding or otherwise, the portions of wire corresponding to the different radial lines have electrical continuity and provide a path for the flow of electric current in a single and same direction of rotation, so that the contributions to the respective electromagnetic field of each turn and each spiral or radial line, are added constructively. Several pairs of spirals Sn, Sn + 1 are arranged axially side by side, around the bottom 33b of the support 33, and are interconnected or brought into electrical contact with each other by their external ends, for example with a weld 42. Therefore, the winding 34 of this second embodiment of the invention requires welding only on the outer portion of said winding, which facilitates the realization.

On the other hand, the support of such a coil 34 optionally comprises a side wall 33c, mounted on the bottom 33b, for example by clip-fastening or plastic welding, after all the pairs of spirals have been mounted on said bottom 33b as shown in FIG. 6. The method of winding the wire 35 and the device for carrying out such a method is described below by each of its steps, and for which reference is made to FIG. 7. The device for implementing the method comprises a first tool 51 and a second tool 52, each tool 51, 52 having a substantially conical shape and being mounted co-axially about an axis 50 in opposition, that is to say say vertices 53,54 respectively of each conical tool 51, 52 facing each other. The device further comprises drive means (not shown) for rotating together said first and second tools 51, 52 in a predetermined direction of rotation about said axis 50. The end of the wire 35 is held on the periphery the base 55 of the first tool 51; then said tools 51, 52 are rotated. Simultaneously, a wire guide (not shown) is caused to move axially from the base 55 of the first tool 51 to the base 56 of the second tool 52, as shown in Figure 7. Then the wire 35 is cut. The wire 35 is thus wound around the first tool 51 by forming a convergent conical spiral SCn and around the second tool 52 forming a divergent conical spiral SCn + 1.

The first tool 51 is axially withdrawn in a direction from its top 53 to its base 55, i.e. a direction opposite to the direction D1 of FIG. 7, so that said first tool 51 is separated from the portion of the convergent conical spiral wire SCn.

The portion of the wire of the convergent conical spiral SCn is then deformed axially progressively and in the direction D1 by a third tool (not shown), so that said portion of the wire is placed in one and the same first plane P1 substantially perpendicular to the axis 50. Said portion of the wire then forms a spiral Sn in the plane Pl, corresponding to the radial line n, and shown in dashed lines in FIG. 7. The second tool 52 is then withdrawn axially in a direction from its top 54 towards its base 56, that is to say in a direction opposite to the direction D2 of FIG. 7, so that said second tool 52 is separated from the portion of the wire of the diverging conical spiral Sn + 1. The portion of the wire of the divergent conical spiral Sn + 1 is then deformed axially progressively and in the direction D2 by a fourth tool (not shown) so that said portion of the wire is placed in one and the same second substantially perpendicular plane P2 to the axis 50. Said portion of the wire then forms a spiral Sn + 1 in the plane P2, corresponding to the radial line n + 1, and shown in dashed lines in FIG.

The first P1 and second P2 planes of the spirals Sn and Sn + 1, respectively, are spaced from each other by an axial distance substantially equal to the axial width of the wire 35, and on either side of a median plane 60 substantially perpendicular to the axis 50 and equidistant from each vertex 53, 54 of the first and second tools 51, 52 respectively. In addition, the Sn and Sn + 1 spirals, formed by the method described above, are formed of a single portion of continuous wire. The spiral pair Sn, Sn + 1 is then threaded onto the support 33 as shown in FIG. 6. The turns or turns of each spiral 30 can be tightened by a tangential and opposite movement of each of the outer ends of said Sn, Sn spirals. 1. In addition, the last outer turn of each spiral Sn, Sn + 1 may also be secured to the previous turn or turn, for example by gluing, as described for the first embodiment of the invention. Then, the pair of spirals can be brought into electrical contact with the pair of spirals previously mounted on the support 33. According to a third embodiment of the invention, the coil 34 is made entirely without cutting the wire 35, it is that is, with a single portion of continuous wire from the first radial line to the last radial line. The winding 34 of this embodiment of the invention requires neither a terminal strip 40, nor welding of the inner ends, nor welding of the outer ends, which allows a space saving radially and further improves the rate of Filling the winding 34. In addition, the winding 34 of this third embodiment of the invention does not require welding, which further facilitates the realization. As shown in FIG. 8 similar to FIG. 6 of the second embodiment, an internal turn 45.1 makes it possible to pass continuously from a first radial line 49.1 (spiral S1) to the second radial line 49.2 (spiral S2). and external turn 46.1 makes it possible to pass continuously from the second radial line 49.2 (spiral S2) to the next radial line 49.3 (spiral S3). To achieve such a continuous winding, the portion of the wire 25 corresponding to the radial line 49.1 is wound by a method described later from the outside to the inside. The rotation on an inner turn 45.1 allows the shifting of the wire an axial width of the wire 35 of the radial line 49.1 to the radial line 49.2, and the portion of the wire of the radial line 49.2 is wound from the inside to the outside. Rotation on an outer turn 46. 1 allows the wire to be shifted by an axial width of the wire 35 from the radial line 49.2 to the radial line 49.3.

The portions of the wire corresponding to all the radial lines are wound around the axis 32 in one and the same direction of rotation. Several pairs of spirals Sn, Sn + 1 are arranged axially side by side, around the bottom 33b of the support 33, and are interconnected or brought into electrical contact with each other by their outer ends, for example with a solder or conductive glue. The support 33 of such a coil 34 may be identical to that of the second embodiment. The method of winding the wire 35 and the device for carrying out such a method is described below by each of its steps, and for which reference should also be made to FIG. 9. The device for implementing the method comprises a first tool 61 and a second tool 62, each tool 61, 62 being mounted co-axially about an axis 60. The device further comprises drive means (not shown) for rotating the first tool 61 in a predetermined direction of rotation about said axis 60, and to translate the second tool 62 in the longitudinal direction of the axis 60. It is also possible that the rotational and translational movement is made by the tool 62, the first tool 61 remaining stationary. The first tool 61 has a drum shape, comprising for example an inner cylinder 61a of axis 60, a radial wall 61b extending radially from a first end of said inner cylinder 61a to an outer cylinder 61c extending co- axially around said first cylinder 61a. The first tool 61 thus has an E-shape in longitudinal section passing through the axis 60, comprising an annular cavity 61d around the inner cylinder 61a. The annular cavity 61d makes it possible, for example, to house the first part 33a, 33b of a support 33, the lateral wall 33a of the support 33 bearing against the radial wall 61b of the first tool 61, and the bottom 33b coming around the inner cylinder. 61a of the first tool 61. The second tool 62 has a shape at least partly complementary to said first tool 61, so as to enter said annular cavity 61d of said first tool 61. This second tool 62 comprises for example a support cylinder 63 from around the inner cylinder 61a of the first tool, an annular disk 64 extending radially at a first end of said support cylinder 63, and a slot 65 extending radially from the inside to the outside in the disk 64. According to a variant represented in FIGS. 9a and 10a, the first tool 61 has a longitudinal section passing through the axis 60 in the shape of a T. It comprises, for example, an inner cylinder 61a with an axis 60 and a radial wall 61b extending radially from an end of said inner cylinder 61a. The annular space 61d makes it possible, for example, to house the first part 33a, 33b of a support 33, the side wall 33a of the support 33 bearing against the radial wall 61b of the first tool 61, and the bottom 33b coming around the cylinder. internal 61a of the first tool 61. The second tool 62 has a shape at least partly complementary to said first tool 61, so as to enter said annular space 61d of said first tool 61. This second tool 62 comprises for example a support cylinder 63 coming around the inner cylinder 61a of the first tool, an annular disk 64 extending radially at a first end of said support cylinder 63, a flange 64a disposed on the other side of the support cylinder 63 relative to the disk 64 and a slot 65s extending radially from the inside to the outside in the disc 64. The slot 65 of said second tool 62, more easily seen in Figure 10, allows the passage of the wire 35 from a wire feed.

During the winding of the winding 34, a wire guide (not shown) makes it possible to move the wire 35 alternately radially from a first end 65a of the slot 65 near the inner cylinder 61a of the first tool 61 to a second end 65b of the slot 65 near the outer cylinder 61c of the first tool 61 or the rim 64a according to the second variant.

The end of the wire 35 is for example engaged in an outer opening 61e of the radial wall 61b of the first tool 61, forming a first power supply terminal 43 of said winding 34, and is fixedly held on said first tool 61. Said first tool 61 is rotated. The disk 64 of the second tool 62 is positioned axially at a distance from the radial wall 61b allowing the introduction of at least one axial width of the section of the wire 35. Simultaneously, the wire guide is caused to move radially from the outside inwards, so that the wire 35 is wound from the outside inwards to form a first radial line 49.1 (spiral S1), the first turn of the wire being able to bear against the inner surface of the outer cylinder 61c of the first tool 61. When the wire guide reaches a position corresponding to an axial line 39.1 near the bottom 33b of the support 33, the second tool 62 is caused to move axially along an axial width of the wire section. 35, while the wire guide is caused to move radially from the outside to the inside, then from the inside to the outside, to form an inner coil 45.1. When the wire guide has again reached a position corresponding to an axial line 39.1, the second tool 62 is held in position and the wire guide is caused to move radially from the inside to the outside, to form a second radial line. 49.2 (spiral S2). When the wire guide reaches a position corresponding to an axial line 39.N near the outer cylinder 61c of the first tool 61, corresponding to the Nth turn of the first tool 61, and corresponding to the Nth turn of the radial line 49.2, the second tool 62 is caused to move axially along an axial width of the section of the wire 35, while the wire guide is caused to move radially from the inside to the outside, then from the outside to the inside, to form an external turn 46.1.

When the wire guide has again reached a radial position corresponding to the axial line 39.N, the second tool 62 is held in position and the wire guide is caused to move radially from the outside to the inside, to form a third radial line 49. 3 (spiral S3) in the same way as for the radial line 49.1 (spiral Si). The winding process thus continues from the first radial line 49.1 to the last radial line 49.M, corresponding to the Mth radial line of the coil 34. A coil 34 comprising M radial lines of N turns (or 15 turns) is thus formed radial line after radial line, continuously and without ever cutting the wire 35 during its winding. The coil 34 can then be trapped in the support 33 by mounting a side wall 33c on the bottom 33b of said support, by a method already explained in the second embodiment of the invention or by folding. The wire 35 is then engaged by the wire guide in an opening of the side wall 33c, and the wire 35 is cut, forming a second power supply terminal 44 of said winding 34. Then, the support assembly 33 and winding 34 can be extracted from the inner cylinder 61a of the first tool 61, to be mounted on the annular core 36 of a rotor 12 of a rotating electrical machine, and electrically connect the first 43 and second 44 power terminals to slip rings 71, 72 of the shaft 14 of the rotor 12 as can be seen in FIG. 11. It will be understood that for all the embodiments of the invention, the first power supply terminal 43 is located near a first side wall 33a of the support 33, while the second supply terminal 44 is advantageously located near a second side wall 33c of the support 33, longitudinally opposite said first side wall 33a, the coil 34 being located between said first side wall 33a and said second side wall 33c. Accordingly, the rotor 12 advantageously comprises a first slip ring 71 mounted on the shaft 14 near the pole wheel 20, to which is connected the first power supply terminal 43, and comprises a second slip ring 72 mounted on the shaft 14 near the pole wheel 22, on which is connected the second supply terminal 44 of the coil 34. As shown in Figure 1 1, the rotor 12 therefore comprises pole wheels 20, 22 located between a first slip ring 71 and a second slip ring 72.

Claims (19)

A method of winding a winding of the rotor of a rotating electrical machine, wherein: the winding comprises at least one wire (35) and an axis about which said wire (35) is wound in at least one determined direction of rotation, sections of the wire in a half-plane passing through the axis of the coil are juxtaposed at each turn next to one another, axially and radially to constitute in said half-plane a mesh of axial lines. (39) and radial lines (49), said method of winding a winding being characterized in that the wire (35) is wound around the axis of the winding, so as to form the radial line mesh after radial line, so that the continuous portion of the wire (35) which corresponds to a radial line (49) has substantially the shape of a spiral in a plane substantially perpendicular to said axis. The winding method according to claim 1, wherein the winding comprises an inner side of the axis side and an outer portion of the opposite side of the axis, and wherein: the portion of the wire (35) corresponding to a radial line n is wound from the outside to the inside, - the portion of the wire (35) corresponding to a radial line n + 1 adjacent to the radial line n is wound from the inside to the outside; and, the portions of the wire (35) corresponding to the radial lines n and n + 1 are wound around the axis in the same direction of rotation, where n is an index designating the rank of the radial lines along the axis. 3. Winding method according to claim 2, wherein the portion of the wire (35) corresponding to the radial line n and the portion of the wire (35) corresponding to the radial line n + 1 are continuous, that is to say say without interruption of the wire. 4. A winding method according to claim 3, wherein: - the portion of the wire (35) corresponding to the radial line sn convergent spiral is wound on a first tool (51) of substantially conical shape, so that the portion of the wire (35) corresponding to each turn is placed axially with respect to the portion of the wire (35) corresponding to the preceding turn at an axial distance greater than an axial width of the wire (35), ~ o - the first tool is removed (51) and the portions of the wire (35) respectively corresponding to all the portions of the wire (35) corresponding to the radial line n are pushed back so that they are in the same first plane (P1) substantially perpendicular to the axis. 5. A winding method according to claim 4, wherein: the portion of the wire (35) corresponding to the radial line n + 1 in a diverging spiral is wound on a second tool (52) of substantially conical shape, of such so that the portion of the wire (35) corresponding to each turn is placed axially with respect to the portion of the wire (35) corresponding to the preceding turn at an axial distance greater than the axial width of the wire (35), - the second wire is removed. tool (52) and the portions of the wire (35) respectively corresponding to all the portions of the wire (35) corresponding to the radial line n + 1 are pushed back so that they are in the same substantially perpendicular second plane (P2) to the axis and at an axial distance from the first plane (P1) substantially equal to said axial width of the wire (35). The winding method according to claim 1, wherein the coil comprises an inner side of the axis side and an outer portion of the opposite side of the axis, and wherein: the portion of the wire (35) corresponding to a radial line n is wound around the axis in a first direction of rotation (R1), and- the portion of the wire (35) corresponding to a radial line n + 1 adjacent to the radial line n is wound around the axis in a second direction of rotation (R2) opposite said first direction of rotation (R1), and - the portion of the wire (35) corresponding to the radial line n and the portion of the wire (35) corresponding to the radial line n + 1 are wound from the inside to the outside, where n is an index indicating the rank of the radial lines along the axis. 7. Winding method according to claim 6, wherein: the portion of the wire (35) corresponding to each radial line (49) comprises an inner end and an outer end, and the inner end of the portion of the wire. (35) corresponding to the radial line n is electrically connected to the inner end of the portion of the wire (35) corresponding to the radial line n-1 by a first connection means, and - the outer end of the portion of the wire (35) corresponding to the radial line n is electrically connected to the outer end of the portion of the wire (35) corresponding to the radial line n + 1 by a second connection means. 8. A winding method according to claim 7, wherein: the first connecting means is a connection bar (40) of substantially rectilinear shape comprising a succession of conductive pads (41) and insulating portions (42) alternating, said connecting strip (40) being positioned radially in contact with all the inner ends of the portions of the wire (35) corresponding to the radial lines (49) of the coil so that the successive internal ends of the portions of the wire (35) corresponding to radial lines n and n-1 are welded to the same wafer (41) of the connection strip (40); and the second connection means is a weld (46). 9. Winding method according to claim 8, in which: the winding is made around a support (33) of section in the half-plane passing through the U-shaped axis, and with side walls ( 33a, 33c) in planes substantially perpendicular to the axis and carried by the lateral branches of the U, and a bottom (33b) enveloping said axis and carried by the base of the U; and, the connection strip (40) is locked on said bottom (33b) of the support (33). 10. A winding method according to claim 1, wherein the winding is carried out continuously with a single wire. 11. Winding method according to the preceding claim characterized in that the winding is formed by two concentric tools (61, 62) movable relative to each other in rotation and in translation. 15 12. A winding method according to any one of the preceding claims, wherein the portion of the wire (35) corresponding to the radial line has a number of turns different from the number of turns of the portion of the wire (35) corresponding to the adjacent radial line n + 1. 13. Winding method according to the preceding claim, wherein the winding has a barrel-shaped external profile. 14. Winding method according to any one of the preceding claims, wherein the wire (35) of the coil has a substantially rectangular section. Rotating electric machine rotor, comprising a rotor axis and at least one winding comprising a wire wound around said rotor axis, characterized in that said wire (35) comprises continuous portions, spirally wound each in a plane substantially perpendicular to said rotor axis. Rotor according to the preceding claim, wherein the winding 30 comprises axially a first side and a second side opposite said first side, and the rotor comprises a rotor shaft (14) around which said winding is mounted, and said rotor comprises - first side of the winding, a first slip ring (71) mounted on the rotor shaft (14) and electrically connected to a first power supply terminal (43) of the winding, and - on the second winding side, a second ring collector (72) mounted on the rotor shaft (14) and electrically connected to a second power supply terminal (44) of the winding, the first and second slip rings (71, 72) being adapted to supply electrical power to the winding winding. 17. Rotor according to claim 15 or claim 16, wherein the wire (35) has a substantially rectangular section. 18. Alternator comprising a rotor according to one of claims 13 to 15. 15 19. Alternator-starter comprising a rotor according to one of claims 15 to 17.