Wound rotor of an electric machine, provided with electrical connection devices

Abstract

The present invention relates to a rotor (1) for an electric machine, comprising a rotary shaft (100), a rotor body comprising at least one winding (200), and electrical connection devices intended to electrically connect the ends of the winding of the rotor (1) to an excitation system of the rotor (1), the rotor (1) being characterized in that at least one of the electrical connection devices comprises a radial connector (500) positioned in a radial cutout of the rotary shaft (100) and an axial connector (700) positioned in an axial cutout of the rotary shaft (100), and in that the rotor (1) further comprises means for fastening the radial connector (500) to the axial connector (700).

Description

[0001] DESCRIPTION

[0002] Title of the invention: Wound rotor of an electric machine provided with electrical connection devices

[0003] The present invention relates to the fields of electrical engineering and automobiles, and more specifically concerns a wound rotor of an electrical machine, finding a particular application in the automotive field.

[0004] Electric or hybrid vehicles are equipped with electrical machines to provide torque to the wheels of these vehicles. Some of these electrical machines use wound rotors rather than permanent magnet rotors. Wound rotors have the advantage of not using rare earths and not having magnetic poles that demagnetize during operation of the electrical machines containing them, when their temperature rises.

[0005] A wound rotor nevertheless needs to be coupled to an electrical excitation system for this wound rotor, and therefore requires an electrical connection between the ends of the rotor windings and the excitation system. This uses, for example, carbon brushes rubbing on copper rings fixed to one end of a rotating rotor shaft. In order to electrically connect the end of the rotating rotor shaft to the ends of the rotor windings, while protecting the electrical conductors ensuring this connection, overmolding of these electrical conductors is generally used.

[0006] The electrical conductors thus overmolded are for example arranged in grooves hollowed axially in a bearing of the rotating shaft, and pass under the inner ring of a bearing in which the rotating shaft is rotatably mounted, the outer ring of the bearing being integral with a fixed part of the electrical machine comprising the wound rotor. However, such an arrangement deforms the bearing and generates acoustic excitation of the electrical machine.

[0007] Another solution is to thread the electrical conductors into holes in the rotating shaft, so as not to modify the cylindrical surface of the rotating shaft supporting the bearing in which it is mounted in rotation, then to inject resin into these holes to electrically insulate the electrical conductors from the rotating shaft, generally made of steel. However, such electrical insulation is difficult and expensive to achieve.

[0008] The present invention aims to remedy at least in part the aforementioned drawbacks by providing a wound rotor of an electric machine as well as a method of connecting the ends of the windings of such a rotor to a rotor excitation system, which make it possible not to deform a cylindrical surface of a rotating shaft of the rotor, intended to receive a bearing, while being simple and inexpensive to produce.

[0009] To this end, the invention provides a rotor for an electrical machine, comprising a rotating shaft, a rotor body comprising at least one winding, and electrical connection devices intended to electrically connect the ends of the rotor winding to an excitation system of the rotor, the rotor being characterized in that at least one of the electrical connection devices comprises a radial connector arranged in a radial recess of the rotating shaft and an axial connector arranged in an axial recess of the rotating shaft, and in that the rotor further comprises means for fixing the radial connector to the axial connector.

[0010] It should be noted that in this patent application, the term "axial" refers, unless otherwise stated, to a direction parallel to the axis of rotation of the rotor of the electric machine. Similarly, the term "radial" refers, unless otherwise stated, to a direction orthogonal to the axis of rotation of the rotor of the electric machine, and secant to this axis of rotation, while the terms "angular" or "ortho-radial" refer, unless otherwise stated, to a direction orthogonal to the axial direction and to a radial direction, this orthogonal direction being in fact rotating around the axis of rotation of the rotor.

[0011] The electrical connection devices of the wound rotor according to the invention electrically connect, once the rotor is mounted in the electrical machine, the ends of the rotor winding(s) to an electrical connection system to the excitation system of the rotor, the electrical connection system being mounted on one end of the rotating shaft of the rotor, and consisting for example of copper rings capable of cooperating with carbon brushes of the excitation system. The electrical connection system is located axially opposite the ends of the windings relative to a cylindrical surface of the rotating shaft receiving a bearing in which the rotating shaft is mounted for rotation. The ends of the windings are the ends of one or more wires forming the windings or of electrical conductors connecting several ends of winding wires together.

[0012] Of course, other electrical connection systems can be used at the end of the rotating shaft, for example metal discs capacitively coupled to the rotor excitation system.

[0013] Thanks to the invention, it is not necessary to pass electrical wires forming bends through a rotating shaft, since two connectors are used for one end of the winding to be connected to the excitation system, each connector being able to be inserted without deformation by a simple translation into a radial or axial recess of the rotating shaft of the rotor. The radial recess of course intersects the axial recess. This embodiment makes it much easier to insulate the electrical conductors of the two connectors from the rotating shaft.

[0014] Finally, the invention makes it possible to mount the rotor in rotation in a bearing located around an axial recess of the rotating shaft, without modifying the cylindrical surface of the rotating shaft on which the internal ring of the bearing is arranged.

[0015] Of course, preferably, all the electrical connection devices of the rotor, intended to electrically connect the ends of the rotor windings to a rotor excitation system, are designed identically, being angularly offset on the rotating shaft of the rotor. In particular for a rotor according to the invention supplied with direct current and comprising only two winding ends to be connected to the excitation system, the rotor comprises only two electrical connection devices, identical and arranged at 180° from each other on the rotating shaft of the rotor.

[0016] According to an optional and advantageous characteristic of the invention, the radial connector comprises an electrical conductor and a body electrically insulating the electrical conductor with respect to the rotating shaft. This insulating body is for example a cylindrical overmolding around a part of the electrical conductor of the radial connector, allowing a non-zero insulation distance with the rotating shaft over the entire length of the radial recess. The diameter of this cylindrical overmolding is for example identical to that of the radial recess, apart from an insertion clearance, which makes it possible to control the position of the radial connector in the radial recess during its assembly. According to another optional and advantageous characteristic of the invention, the radial connector comprises a sealing device arranged around the insulating body. This sealing device is for example an O-ring seal housed in a groove of the insulating body.It prevents the introduction of cooling oil into the radial recess of the rotating shaft, when the rotor windings are oil-cooled.

[0017] According to another optional and advantageous characteristic of the invention, the electrical conductor of the radial connector comprises a threaded orifice capable of receiving a thread of an electrical conductor of the axial connector. In order to allow such a screwed connection between the electrical conductor of the radial connector and the electrical conductor of the axial connector, the insulating body of the radial connector comprises, for example, when it extends radially along this screwed connection, a recess at the level of the threaded orifice to allow the thread of the axial connector to access this threaded orifice.

[0018] According to another optional and advantageous characteristic of the invention, the axial connector comprises a body electrically insulating the electrical conductor of the axial connector relative to the rotating shaft. This insulating body has, for example, the shape of a cylindrical sheath allowing a non-zero insulation distance with the rotating shaft over the entire length of the axial recess. The diameter of this cylindrical sheath is, for example, identical to that of the radial recess, apart from an insertion clearance, which makes it possible to control the position of the axial connector in the axial recess when it is mounted on the rotating shaft.

[0019] According to another optional and advantageous characteristic of the invention, the electrical conductor of the axial connector comprises a threaded end piece, capable of being screwed into the threaded orifice of the electrical conductor of the radial connector. The threaded end piece is for example a cylindrical portion of the electrical conductor of the axial connector, the surface of which comprises the thread capable of allowing it to be screwed into the threaded orifice.

[0020] Preferably, in order to facilitate the attachment of the axial connector to the radial connector, the axial connector comprises a recess capable of receiving a tool for attaching the axial connector to the radial connector. The electrical conductor of the axial connector is for example formed of several cylindrical portions, one of which has a larger diameter and has the recess on its free axial end surface, the thread being produced on a cylindrical portion of smaller diameter. In addition, when the insulating body of the axial connector is a cylindrical sheath, the electrical conductor of the axial connector is for example free to rotate in this cylindrical sheath, which envelops the cylindrical portion of larger diameter of the electrical conductor of the axial connector.

[0021] In one embodiment of the invention, the rotor according to the invention comprises a locking device provided with a device for angular positioning of an electrical terminal projecting from the radial connector, the angular positioning device being capable of moving the electrical terminal from an intermediate position to a final position. In this embodiment, the electrical terminal in which the winding end is crimped or welded comprises a slide whose sliding axis can take several angular positions relative to a longitudinal axis of the radial recess in which the radial connector is inserted, this longitudinal axis being radial relative to the axis of rotation of the rotating shaft. This slide is itself arranged at the end of a portion of the electrical conductor of the radial connector, this portion projecting from the insulating body of the radial connector and being able to have a bent shape.Here the intermediate or final position of the electrical terminal, formed by the slide and this portion of electrical conductor, therefore refers to angular positions of the sliding axis and / or the elbow formed by the portion of electrical conductor, relative to the longitudinal axis of the radial recess in which the radial connector is arranged. The slide axis and / or the elbow can in fact evolve angularly around this longitudinal axis, in a plane orthogonal to this longitudinal axis.

[0022] The locking device preferably acts on all the electrical terminals of the rotor. In particular, in the intermediate position, it allows the slides of the electrical terminals to be kept away, in the axial direction, from the windings of the rotor, and therefore to facilitate the crimping and / or soldering of the winding ends in the electrical terminals, this crimping and / or soldering requiring a bulky tool. The locking device also allows the electrical terminals to be held in their final position, once the wires forming the winding ends have been crimped and / or soldered, these wires being taut compared to their state in the intermediate position of the electrical terminals. The locking device therefore allows, by this tension of the wires, to control the insulation distances between the different elements of the rotor.

[0023] The locking device is, for example, a bolt enclosing a cylindrical portion of the rotating shaft and capable of taking several positions on the rotating shaft in the axial direction, depending on the intermediate or final position in which the electrical terminals are located.

[0024] The radial recess is for example made in a cylindrical portion of the rotating shaft, the locking device being able to be threaded onto the cylindrical portion of the rotating shaft.

[0025] The insulating body of the radial connector comprises, for example, a collar from which the electrical terminal protrudes, the collar comprising a locking stop and a rotation cam of the radial connector, capable of cooperating with the locking device.

[0026] The angular positioning device comprises, for example, a notch capable of receiving the collar, the notch comprising a stop capable of holding the rotation cam in the intermediate position, and a base provided with a shape complementary to the locking stop.

[0027] The locking device of course preferably comprises as many notches as there are radial connectors on the rotating shaft, each comprising a collar as mentioned above and positioned in radial recesses on the cylindrical portion of the rotating shaft. Preferably of course, each radial recess comprising a radial connector according to the invention is shaped in a similar manner.

[0028] Thus, when the locking device is hooped onto the cylindrical portion of the rotating shaft, the openings of the notches being opposite the collars, the stops of the notches first block the rotation cams of the collars in the intermediate position, and allow the crimping and / or soldering of the winding end wires in the electrical terminals. Then, the bottoms of the notches being brought by the hooping of the locking device towards the collars, the rotation cams rotate the radial connectors until the locking stops of the collars are blocked against the bottoms of the notches, the electrical terminals then being in their final position.

[0029] In order to radially lock the radial connector in the radial recess in the final position, the radial recess comprises, for example, a counterbore capable of receiving the collar, and the collar comprises a ring positioned radially between a bottom of the counterbore and the locking device in the final position. The ring is, for example, formed in the collar by flats in the upper part of the collar, the flats partly delimiting the rotation cam and the locking stop.

[0030] Furthermore, when the cylindrical portion of the rotating shaft onto which the locking device is shrunk corresponds to a bearing of the rotating shaft, extending a flat surface of another cylindrical portion of larger diameter of the rotating shaft, the locking device preferably comes, in the final position, into abutment against this flat surface. Thus the position of the locking device is controlled relative to the radial connectors.

[0031] The invention also relates to a method for electrically connecting the winding ends of a rotor according to the invention to a rotor excitation system, comprising steps of:

[0032] - insertion of the radial connector into the radial recess,

[0033] - introduction of the locking device on one end of the cylindrical portion of the rotating shaft,

[0034] - intermediate positioning of the electrical terminal by locking the rotation cam of the collar of the radial connector in the stop provided in the notch of the locking device,

[0035] - crimping one end of the winding into the electrical terminal,

[0036] - locking the locking device relative to the rotating shaft, causing the electrical terminal to rotate to its final position in which the locking stop of the collar of the radial connector is fitted into the complementary shape of the bottom of the notch of the locking device, and in which the threaded orifice is positioned angularly facing the axial recess, and

[0037] - fixing the axial connector to the radial connector.

[0038] The connection method according to the invention of course also includes a step of connecting the axial connector to an electrical connection system present on one end of the rotating shaft, to the rotor excitation system, this electrical connection system being able to take various forms depending on the excitation system chosen.

[0039] The invention also relates to an electrical machine comprising a rotor according to the invention. The connection method according to the invention and the electrical machine according to the invention have advantages similar to those of the rotor according to the invention.

[0040] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0041] [fig 1] represents in perspective a face of a wound rotor according to the invention, in one embodiment of the invention, electrical terminals in which rotor winding wires are crimped being in a locked position called final,

[0042] [fig 2] represents in perspective a stripped end of a rotating shaft of the wound rotor of figure 1,

[0043] [fig 3] is a front view of the stripped end of figure 2,

[0044] [fig 4] is an axial sectional view of the stripped end of figure 2,

[0045] [fig 5] is a perspective view of a radial connector of an electrical connection device of the wound rotor of figure 1,

[0046] [fig 6] is another perspective view of the radial connector of figure 5,

[0047] [fig 7] is a sectional view of an axial connector of an electrical connection device of the wound rotor of figure 1, attached to the radial connector of figure 5,

[0048] [fig 8] is a perspective view of several axial connectors identical to those of figure 7, connected by an insulating stop,

[0049] [fig 9] is another perspective view of the axial connectors of figure 8,

[0050] [fig 10] is an axial sectional view of an end portion of the wound rotor of figure 1,

[0051] [fig 11] is a sectional view of the axial connector assembly of figure 7 and radial connector of figure 5, fixed to each other,

[0052] [fig 12] is a perspective view of a device for locking the electrical terminals of the wound rotor of figure 1,

[0053] [fig 13] is a top view of the locking device in which the electrical terminals are in the locked position and connected via radial connectors to which they belong, to the axial connectors of figure 8, the rotating shaft not being shown,

[0054] [fig 14] is a partial perspective view of the locking device, radial connectors and axial connectors assembly in the locked position of figure 13,

[0055] [fig 15] is another partial perspective view of the whole of figure 13,

[0056] [fig 16] is a partial front view of the whole of figure 13,

[0057] [fig 17] is an axial sectional view of an end portion of the wound rotor of figure 1, in an intermediate position of the electrical terminals of the rotor, these being not locked in this intermediate position, the winding ends not yet being crimped and / or soldered in the electrical terminals,

[0058] [fig 18] is a perspective view of one face of the rotor of figure 1 in this intermediate position of the electrical terminals,

[0059] [fig 19] is a top view of the locking device of figure 12, in which the electrical terminals are in an intermediate position and not yet connected via radial connectors to the axial connectors of figure 8, the rotating shaft not being shown,

[0060] [fig 20] is a perspective view of the locking device assembly, radial connectors and axial connectors in the intermediate position of figure 19,

[0061] [fig 21] is a sectional view of the assembly of figure 20,

[0062] [fig 22] is a partial perspective view of the whole of figure 20,

[0063] [fig 23] is a partial front view of the whole of figure 20, and

[0064] [fig 24] shows steps in a method of electrically connecting the winding ends of the rotor of figure 1 to a rotor excitation system.

[0065] According to an embodiment of the invention shown in Figure 1, a rotor 1 for an electrical machine according to the invention comprises a rotating shaft 100, on which is mounted a stack of sheets 300 (visible in Figure 10) forming rotor teeth. On the axial ends of these teeth, winding supports 400 (visible in Figure 10) made of insulating material are positioned so as to each receive a winding of one of the rotor teeth. The rotor body therefore comprises a set of windings 200, the ends 201 of which must be connected to an excitation system of the rotor 1. A metal ring 800 also makes it possible to maintain the winding heads of the rotor 1 and to allow the balancing of the rotor 1. The latter must in fact have a uniformly distributed mass when it rotates around an axis of rotation X, parallel to the axial direction.

[0066] In order to connect the winding ends 201 to the excitation system of the rotor 1, in this embodiment of the invention, electrical terminals 501 are used in which the winding ends 201, here two copper wire ends, are crimped or soldered using a bulky clamp. In addition, electrical connection devices are used, each comprising a radial connector 500 (shown in FIG. 5) and an axial connector 700. The rotor 1 is therefore equipped with two electrical connection devices, each connecting an electrical terminal 501 to an end surface of the rotating shaft 100 on which is arranged an electrical connection system to the excitation system of the rotor 1, for example rings.

[0067] We will now describe in relation to figures 2 to 4, the structure of the end of the rotating shaft 100 in which each of the radial 500 and axial 700 connectors are arranged.

[0068] The end of the rotating shaft 100 comprises a first bearing 108 forming a shoulder of a cylindrical structure of the rotating shaft 100 carrying the body of the rotor 1, this first bearing 108 comprising two radial recesses 104 arranged at 180° to one another on this first bearing 108, and each intended to receive a radial connector 500. Each radial recess 104 comprises a counterbore 103 serving to receive a collar 510 (referenced figure 5) of a radial connector 500.

[0069] The cylindrical structure of the rotating shaft 100 carrying the body of the rotor 1 is connected to the first bearing 108 by a flat surface 107, and the first bearing 108 is connected to a second bearing 102 of smaller diameter by another flat surface 109. Finally, a last bearing, not referenced, forms a shoulder in the second bearing 102 and adjoins an axial end surface 106 of the rotating shaft 100, in the form of a crown, in which two axial recesses 105 are hollowed out, arranged at 180° from each other on this crown shape. Each axial recess 105 is intended to receive an axial connector 700. A central recess 101 in the middle of the axial end surface 106 allows the insertion of a centering tool used during the assembly of the rotor 1.When the rotating shaft 100 is cut along the plane AA shown in Figure 3, this plane passing through the axis of rotation X and through a central axis of each axial recess 105, the sectional view of Figure 4 is obtained, in which it can be seen that each axial recess 105 intersects a radial recess 104. These recesses are for example produced by cylindrical bores in the rotating shaft 100. Each radial recess 104 therefore has an axis of symmetry arranged radially and each axial recess 105 has an axis of symmetry arranged axially.

[0070] This arrangement makes it possible to electrically connect each radial connector 500 inserted in a radial recess 104, to an axial connector 700 inserted in an axial recess 105, at the intersection of these recesses. This makes it possible not to modify the surface of a bearing of the rotating shaft, for example the second bearing 102, on which will be positioned a bearing fixed by its external ring to a fixed part of the electrical machine.

[0071] Alternatively, the end of the rotating shaft has more or fewer bearings than in this embodiment, the radial recesses being arranged in any of these bearings provided that a cylindrical surface remains intact for positioning a bearing between the radial recesses and the axial end surface of the rotating shaft.

[0072] We will now describe in relation to figures 5 and 6, one of the radial connectors 500, the two radial connectors 500 being identical.

[0073] The radial connector 500 comprises an insulating body 506, for example made of glass fiber reinforced polyamide, this insulating body 506 being crossed in its length by an electrical conductor 5017 (referenced figure 10), for example made of copper, a portion of which protruding from the insulating body, forms the electrical terminal 501. The electrical conductor 5017 comprises a threaded orifice 507 allowing a screwed connection with an axial connector 700. For this purpose, the insulating body 506 comprises a lateral recess 508 leaving a portion of the electrical conductor 5017 bare comprising the threaded orifice 507, and forming a mouth for receiving a thread of the axial connector 700.The lateral recess 508 has a diameter corresponding, to within an insertion clearance, to that of an insulating body 701 (referenced figure 7) of an axial connector 700 so that the electrical connection between the radial connector 500 and the axial connector 700 is protected by their respective insulating bodies 506 and 701, the insulating body 701 of the axial connector 700 being inserted partly in the lateral recess 508. The insulating body 506 is overmolded on a portion of the electrical conductor 5017 intended to be inserted in a radial recess 104, in order to electrically insulate this portion of the electrical conductor 5017 with respect to the rotating shaft 100, made of steel.

[0074] The insulating body 506 comprises a collar 510 intended to bear on the counterbore 103 of the radial recess 104. Between the collar 510 and the lateral recess 508, a circular groove is arranged on the insulating body 506. This circular groove receives an O-ring seal 504 which makes it possible to prevent cooling oil spraying the windings 200 from going towards the bottom of the radial recess 104.

[0075] The collar 510 comprises several flats forming a ring 505 in the lower part of the collar 510, this ring 505 comprising a lower surface 509 for bearing on the counterbore 103. One of the flats forms a locking stop 502 of the radial connector 500, and the other partly delimits a rotation cam 503 projecting radially, relative to a longitudinal axis of the radial connector 500, from the collar 510. The longitudinal axis of the radial connector 500 coincides with the axis of symmetry of the radial recess 104 in which it is inserted.

[0076] The locking stop 502 forms a flat surface orthogonal to the central axis of the tapped hole 507. The rotation cam 503 of the radial connector 500 is arranged laterally to the locking stop 502 so as to project from the collar 510 on the side opposite the locking stop 502. The respective functions of the locking stop 502 and the rotation cam 503 will be explained later.

[0077] The insulating body 506 also comprises a half-cylinder 511 surmounting the collar 510 so as to overmold one face of an elbow formed by the electrical terminal 501. The latter comprises at its free end a slide allowing the insertion of a wire into the slide to crimp it and / or solder it there. The electrical terminal 501 forming an elbow relative to the rest of the electrical conductor 5017 of the radial connector 500, can take several angular positions relative to the longitudinal axis of the radial connector 500.

[0078] In particular when the slide of the electrical terminal 501 is distant from the body of the rotor 1, it is in an intermediate position allowing a large clamp to be brought in for crimping and / or welding a winding end 201 into the slide, the latter being positioned axially at the level of the second bearing 102. On the contrary, when the slide is close to the rotor body 1, the electrical terminal 501 is generally parallel to the flat surfaces 107, 109 of the rotating shaft, in a so-called final position, not conducive to welding or crimping the winding end 201 into the slide. The slide of the electrical terminal 501 is then positioned axially at the level of the first bearing 108.

[0079] For information purposes, in the intermediate position, the electrical terminal 501 forms an angle of approximately 68° with the flat surfaces 107, 109 of the rotating shaft 100, in a plane orthogonal to the axis of symmetry of the radial recess 104 in which the radial connector 500 is inserted.

[0080] We will now describe in relation to figures 7 to 9, one of the two axial connectors

[0081] 700, the two axial connectors 700 being identical.

[0082] The axial connector 700 comprises an electrical conductor 704, for example made of copper, formed of several cylindrical portions. The larger diameter cylindrical portion of the electrical conductor 704 is contained in an insulating body 701 in the form of a sheath, this insulating body being for example made of polyamide loaded with glass fibers.

[0083] The electrical conductor 704 can rotate in the insulating body 701, secured to a crown 702 also made of insulating material, for example made of the same material as the insulating bodies of the axial connectors 700. The crown 702 abuts against the axial end surface 106 of the rotating shaft 100 when the axial connectors 700 are fixed to the radial connectors 500. The crown 702 leaves in its center a passage 703 for a centering tool coming into the central recess 101 of the rotating shaft 100.

[0084] The sheaths constituting the insulating bodies 701 are open at the surface of the crown 702, so as to allow the introduction of a tool into each sheath, the tool having an end of a shape complementary to an imprint 708 formed on a surface of the electrical conductor 704 opposite the opening of the sheath. This imprint allows the electrical conductor 704 to be moved relative to the insulating body.

[0085] 701, in particular to turn it in the insulating body 701 and therefore in the axial recess 105.

[0086] Alternatively, the insulating bodies 701 are integral with the electrical conductors 704, for example molded onto the electrical conductors 704, and are not connected by an insulating ring.

[0087] The electrical conductor 704 comprises, opposite the imprint 708, a reduction in diameter forming a bearing whose surface comprises a thread 707, the bearing corresponding to a threaded end portion 706 of the electrical conductor 704, extended by a tip 705 of smaller diameter, facilitating the positioning of the threaded end portion 706 against the tapped orifice 507 of a radial connector 500 to which it is screwed.

[0088] In Figure 7 the axial connector 700 is shown screwed into the threaded hole 507 of a radial connector 500, in a final position of the electrical terminals 501 of the rotor 1.

[0089] Indeed, in this final position shown in figures 10 and 11, the lateral recesses 508 of the radial connectors 500 are turned to face the openings of the axial recesses 105 in the rotating shaft 100, which allows the axial connectors 700 to be screwed into the tapped orifices 507 positioned in these lateral recesses 508.

[0090] A locking device 600 makes it possible to lock the position of the electrical terminals 501 in this final position and to allow this screwing. Figure 11 shows more visibly the locking device 600 bearing against the locking stop 502 of a radial connector 500, thus locking it in rotation around the longitudinal axis of the radial connector 500.

[0091] As visible in Figure 12, the locking device 600 has the shape of a ring whose internal cylindrical surface is a hooping surface 601 of the locking device 600 on the first bearing 108 of the rotating shaft 100, and whose external cylindrical surface is a surface 604 for winding the winding ends before reaching the slides of the electrical terminals 501. The locking device 600 is made of insulating material, for example polyamide loaded with glass fibers.

[0092] The locking device 600 is therefore a flange comprising two diametrically opposed notches 610 intended to each receive a collar 510 of a radial connector 500 inserted in a radial recess 104. The bottom 603 of each notch 610 is of a shape complementary to the locking stop 502 of a collar 510 of radial connector 500.

[0093] Each notch 610 comprises a lateral surface forming a flank 605 of the flange 510 and a stop 602 in the form of a lateral notch in the flared opening of the notch 610. The notches 610 form a device for angular positioning of the radial connectors 500 relative to the longitudinal axis thereof in their respective radial recesses 104. As visible in Figures 13 to 16, when the radial connectors 500 are in their final position locked by the locking device 600, their locking stops 502 are in contact with the bottoms of the notches 603, blocking their electrical terminals 501 in a position orthogonal to the axis of rotation X of the rotating shaft and parallel to the flat surfaces 107, 109 of the rotating shaft 100, and positioning their lateral recesses 508 facing the openings of the axial recesses 105.

[0094] Furthermore, in this final position, the rotation cams 503 of the radial connectors are arranged against the flap sides 605 of the notches 610. Furthermore, in this final position, the two electrical terminals 501 point in opposite directions parallel to the flat surfaces 107, 109 of the rotating shaft 100, in order to guarantee dynamic balancing of the rotating rotor 1. Finally, in this final position, the locking device 600 is entirely shrunk onto the first bearing 108, that is to say that it abuts against the flat surface 107 of the rotating shaft 100 except of course at the level of the radial connectors 500 which are placed in the notches 610 of the locking device 600.

[0095] Figures 17 to 23 show the radial connectors 500 in an intermediate position, i.e. an unlocked position in which the ends 201 of the windings can be easily crimped and / or soldered into the electrical terminals 501. In this intermediate position, the locking device 600 is not fully shrunk onto the first bearing 108, being axially separated by one centimeter from the flat surface 107 formed by the first bearing 108 on the rotating shaft 100.

[0096] In this intermediate position, the radial connectors 500 can therefore rotate in their radial recesses 104, their collars 510 being able to rotate until the rotation cam 503 of each collar 510 comes into abutment against the stop 602 of the corresponding notch 610. In this intermediate position, the rotation cams 503 of the collars 510 are held against the stops 602 of the notches, the electrical terminals 510 thus forming an angle of 68° with the flat surface 107 of the rotating shaft 100, which makes it possible to bring a crimping or soldering pliers close to the electrical terminals 501, and to crimp and / or solder the ends 201 of the windings in the slides of the electrical terminals 501, without damaging the other parts of the rotor windings.

[0097] Furthermore, in this intermediate position, as visible in figure 21, the lateral recesses 508 of the radial connectors are not located opposite the openings of the axial recesses 105 and therefore do not allow the axial connectors 700 to be screwed to the radial connectors 500.

[0098] We will now describe in relation to figure 24, a method of electrical connection 900 according to the invention, of the ends 201 of the windings of the rotor 1, to an excitation system of the rotor 1.

[0099] A first step 910 of the method is the insertion of the radial connectors 500 into the radial recesses 104, until the rings 505 of the collars 510 of the radial connectors 500 come into abutment against the counterbores 103 provided in the radial recesses 104. The collars 510 are furthermore positioned angularly, relative to the longitudinal axes of their respective radial connectors 500, so that their rotation cams 503 are turned towards the body of the rotor 1.

[0100] A second step 920 of the method is the shrink fitting of the locking device 600 onto a portion of the first bearing 108 until the ring formed by the locking device 600 is approximately one centimeter from the flat surface 107 of the rotating shaft 100.

[0101] A third step 930 of the method is the intermediate positioning of the electrical terminals 501 by bringing the rotation cams 503 of the collars 510 of the radial connectors 500 against the stops 602 of the notches 610 of the locking device 600. The electrical terminals 501 then form an angle of approximately 68° with the flat surface 107 of the rotating shaft, thus moving the slides of the electrical terminals 501 away from the body of the rotor 1.

[0102] A fourth step 940 of the method is the winding of the wire portions comprising the winding ends 201 of the rotor 1, around the insulating ring formed by the locking device 600, until the winding ends 201 reach the slides of the electrical terminals 501. The winding ends 201 are then inserted into the slides and then crimped and / or soldered into the slides of the electrical terminals 501.

[0103] In a fifth step 950 of the method, the hooping of the locking device 600 is continued on the first bearing 108 of the rotating shaft 100, which causes the rotation cams 503 to rotate until the locking stops 502 come into contact with the bottoms 603 of the notches 610 of the locking device 600. The electrical terminals 501 are then in their final position, the locking device 600 comes into contact with the flat surface 107 of the rotating shaft, the lateral recesses 508 of the radial connectors 500 are turned to face the openings of the axial recesses 105, and the rings 505 of the collars 510 are positioned radially between the counterbores 103 and the locking device 600, which prevents the radial connectors 500 from being removed. This fifth step 950 also makes it possible to tension the wires forming the ends 201 of the rotor winding.This tension of the wires allows them to be kept in position despite the centrifugal force to which they are subjected during the rotation of the rotor 1 and therefore to prolong their service life, the flexible wires being able to move and become damaged during this rotation of the rotor 1.

[0104] A sixth step 960 of the method is the screwing of the threads of the axial connectors 700 into the tapped holes 507 of the radial connectors 500, through their lateral recesses 508, of a diameter allowing the insulating bodies 701 of the axial connectors 700 to be received. For this, the axial connectors 700 are inserted into the axial recesses 105, then a tool is inserted into the recesses 708 of the axial connectors 700, and the axial connectors 700 are pushed using this tool until the threaded end parts 706 of the electrical conductors 704 reach the tapped holes 507. Then, using this tool, the threads 707 of the electrical conductors 704 are screwed into the tapped holes 507. At the end of screwing, the crown 702 insulating connecting the axial connectors 700 abuts against the axial end surface 106 of the rotating shaft 100.

[0105] A seventh step 970 of the method is the electrical connection of the axial connectors to an electrical connection system at the end of the rotating shaft 100, for example copper rings, allowing a connection to a rotor excitation system based on carbon brushes. Alternatively, another electrical connection system is used at the end of the rotating shaft 100, for example using a capacitive coupling with a corresponding excitation system of the rotor 1.

[0106] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the characteristics of the different variant embodiments of the invention envisaged in this application can be combined to achieve the invention, insofar as these variants are not incompatible with each other.

Claims

CLAIMS 1- Rotor (1) for an electrical machine, comprising a rotating shaft (100), a rotor body comprising at least one winding (200), and electrical connection devices intended to electrically connect the ends (201) of the winding of the rotor (1) to an excitation system of the rotor (1), the rotor (1) being characterized in that at least one of the electrical connection devices comprises a radial connector (500) arranged in a radial recess (104) of the rotating shaft (100) and an axial connector (700) arranged in an axial recess (105) of the rotating shaft (100), and in that the rotor (1) further comprises means for fixing the radial connector (500) to the axial connector (700). 2- Rotor (1) for an electric machine according to claim 1, in which the radial connector (500) comprises an electrical conductor (5017) and an insulating body (506) electrically the electrical conductor (5017) relative to the rotating shaft (100). 3- Rotor (1) for an electrical machine according to claim 2, in which the radial connector (500) comprises a sealing device (504) arranged around the insulating body (506). 4- Rotor (1) for an electric machine according to claim 2 or 3, in which the electrical conductor (5017) of the radial connector (500) comprises a threaded orifice (507) capable of receiving a thread (707) of an electrical conductor (704) of the axial connector (700). 5- Rotor (1) for an electrical machine according to any one of claims 1 to 4, wherein the axial connector (700) comprises an insulating body (701) electrically insulating the electrical conductor (704) of the axial connector (700) relative to the rotating shaft (100). 6- Rotor (1) for an electrical machine according to claims 4 and 5, in which the electrical conductor (704) of the axial connector (700) comprises a threaded end piece (706), capable of being screwed into the threaded orifice (507) of the electrical conductor (5017) of the radial connector (500). 7- Rotor (1) for an electric machine according to claim 6, in which the axial connector (700) comprises an imprint (708) capable of receiving a tool for fixing the axial connector (700) to the radial connector (500). 8- Rotor (1) for an electrical machine according to any one of claims 1 to 7, comprising a locking device (600) provided with a device for angular positioning of an electrical terminal (501) projecting from the radial connector (500), the angular positioning device being capable of moving the electrical terminal (501) from an intermediate position to a final position. 9- Rotor (1) for an electrical machine according to claim 8, in which the radial recess (104) is made in a cylindrical portion (108) of the rotating shaft (100), the locking device (600) being capable of being shrunk onto the cylindrical portion (108) of the rotating shaft (100). 10- Rotor (1) for an electrical machine according to claim 9 taken in combination with claim 2, in which the insulating body (506) of the radial connector (500) comprises a collar (510) from which the electrical terminal (501) projects, the collar (510) comprising a locking stop (502) and a rotation cam (503) of the radial connector (500), capable of cooperating with the locking device (600). 11- Rotor (1) for an electric machine according to claim 10, in which the angular positioning device comprises a notch (610) capable of receiving the collar (510), the notch (610) comprising a stop (602) capable of holding the rotation cam (503) in the intermediate position, and a bottom (603) provided with a shape complementary to the locking stop (502). 12- Rotor (1) for an electric machine according to claim 11, in which the radial recess (104) comprises a counterbore (103) capable of receiving the collar (510), and in which the collar (510) comprises a ring (505) positioned radially between a bottom of the counterbore (103) and the locking device (600) in the final position. 13- Method for electrically connecting (900) the ends (201) of the winding of a rotor (1) according to any one of claims 11 or 12 to an excitation system of the rotor (1), comprising steps of: - insertion (910) of the radial connector (500) into the radial recess (104), - introduction (920) of the locking device (600) on one end of the cylindrical portion (108) of the rotating shaft (100), - intermediate positioning (930) of the electrical terminal (501) by blocking the rotation cam (503) of the collar (510) of the radial connector (500) in the stop (602) formed in the notch (610) of the locking device (600), - crimping and / or welding (940) one end (201) of the winding in the electrical terminal (501), - locking (950) of the locking device (600) relative to the rotating shaft (100), rotating the electrical terminal (501) to its final position in which the locking stop (502) of the collar (510) of the radial connector (500) is fitted into the complementary shape of the bottom (603) of the notch (610) of the locking device (600), and in which the threaded orifice (507) is positioned angularly facing the axial recess (105), and - fixing (960) of the axial connector (700) to the radial connector (500).

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