Axial magnetic flux electric machine with a wound rotor and three-phase electrical supply.

Abstract

Axial magnetic flux electric machine 200 composed of: a central discoid rotor 100 with a structure composed mainly of two flanges 110a, 110b made of composite material which supports rotor cores 130 of magnetic field, multiple of three in number, each surrounded by a coil 140; Two lateral stators 220, 230 constructed on the basis of a frame 221, 231 made of composite material, comprising a radial face 221r, 231r whose openings accommodate the stator pads 222, 232, separated from the rotor 100 by the air gaps 241, multiple of two in number, each carrying a coil 223, 233, and connected to each other, at the rear end, by a yoke 227, 237; A device 300 for supplying the rotor with electric current comprising the rotating elements 320,330,340,350 made of insulating material carrying the crown-shaped plates 331,341,342,351 made of conductive material and each having a connection tab 331u,341v,342w,351n to the rotor collectors 141,142,143,144 by the power supply wires 151,152,153,154, fixed elements 360,370 made of insulating material carrying crown-shaped plates 361,362,371,372, made of conductive material and each having a tab 361u,362v,371w,372n for connection to the external power supply, current transmitting discs 380 interposed between the rotating crown-shaped plates and the fixed crown-shaped plates, characterized in that: The coils of the rotor 100 are supplied with three-phase alternating current via the power supply device 300, at variable frequency, which allows the rotation speed of the electric machine to be controlled. The stator is supplied with direct current which allows the electric machine to be controlled in torque and power. Figure for the abstract: Fig.9,

Description

Title of the invention: Axial magnetic flux electric machine with a wound rotor with three-phase electrical supply. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates generally to the field of axial magnetic flux electrical machines.

[0002] It concerns firstly a discoid rotor with wound magnetic poles, supplied with three-phase electric current, and its cooling method.

[0003] It relates to a stator associated with wound magnetic poles, supplied with direct electric current, and its cooling method. STATE OF THE ART

[0004] Axial magnetic flux electric machines are still not very widespread in the field of automotive electric traction.

[0005] These machines exist according to two architectures.

[0006] In the first type, the rotor is single, central and framed by two stators. The rotor carries permanent magnet pads, more or less segmented to reduce heating, and the stators carry coils supplied with alternating current of variable frequency, intensity and voltage. All speed and power control is done by the stator. The stator is generally cooled by a network in which a liquid circulates. Cooling of the rotor, confined between the stators, is complicated to achieve and is often non-existent. An example is publication FR2999359.

[0007] In the second type, the stator is unique, central and framed by two rotors. The rotors also carry permanent magnet pads, more or less segmented, and the stators also carry coils supplied with three-phase alternating current of variable frequency, intensity and voltage. All speed and power control is also done by the stator. Cooling of the stator is generally ensured, more efficiently, by the circulation of a liquid in direct contact with the coils. The two rotors being arranged laterally to the stator, their cooling is made easier by forced circulation of air from outside the machine. An example is publication US10630157B2.

[0008] There does not appear to be any publication relating to an axial magnetic flux machine having a central wound rotor supplied with three-phase alternating current. PRESENTATION OF THE INVENTION

[0009] the advantage of designing an electrical machine with a wound rotor is that it does not need permanent magnets and is independent of so-called earths. rare.

[0010] The advantage of designing a wound rotor machine powered by three-phase alternating current and separating the power and rotation speed controls.

[0011] The rotation speed of the rotor is determined by the identical sinusoidal frequency of the three phases of the electric current, offset by 120°, which creates a rotating magnetic field. The maximum intensity of the magnetic field in each coil will be a function of the maximum intensity of the current.

[0012] To power the rotor, it is sufficient to have an inverter capable of delivering a three-phase alternating current of variable frequency and fixed and low intensity, which makes it less expensive than those supplying the stators with variable and high intensity.

[0013] Indeed, for a conventional machine with a magnet rotor or a wound rotor powered by direct current, the inverter is the driver of speed and power. It must be able to supply a three-phase alternating current of variable frequency and variable and high intensity.

[0014] To operate this machine with a wound rotor powered by three-phase current, the stator will be powered by direct current of variable intensity. It is the driver of the machine's power. Its power supply is simple since the energy source (the battery) delivers direct current.

[0015] The invention therefore relates to an axial magnetic flux electric machine comprising: • A central discoid rotor with a structure composed mainly of two flanges made of composite material which support magnetic field conducting cores, a multiple of three, each surrounded by a coil powered by one of the three phases of an alternating current, and an arrangement of the cores allowing circulation of air for cooling the coils. • Two lateral stators constructed on the basis of a composite material frame, comprising an outer ring, an inner ring, a radial face with openings accommodating the stator pads of a number multiple of two, which face each other, at a short distance from the rotor, each carrying a coil, and linked to each other, at the rear end, by a magnetic flux looping yoke. The frame being closed, opposite its radial face, by an attached cover, forms a sealed chamber in which a cooling fluid circulates. The coils are supplied with direct current of variable intensity and in such a way that two consecutive coils generate a magnetic field in the opposite direction and that two stator pads opposite each other, one belonging to the left stator and the other to the right stator, create fields in the same direction. DETAILED DESCRIPTION OF THE INVENTION

[0016] These characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows and with regard to the appended drawings given as non-limiting examples and in which:

[0017] [Fig. l]is a front view of the assembled rotor disc.

[0018] [Fig.2]is a front view of the incomplete disc, without the peripheral reinforcement ring and without the front flange.

[0019] [Fig.3] is a first AA section of the assembled disc.

[0020] [Fig.4]is a second BB section of the assembled disc.

[0021] [Fig.5]is a third CC section of the assembled disc.

[0022] [Fig.6]is a fourth DD section of the assembled disc.

[0023] [Fig.7]is the description of the left stator.

[0024] [Fig.8]is the description of the right stator.

[0025] [Fig.9]is a section of the electric machine.

[0026] [Fig. 10]is a partial section of the electric machine, with focus on the rotor current supply device.

[0027] [Fig. 1 l]is a UU section of the rotor current supply device corresponding to phase 1.

[0028] [Fig. 12]is a VV section of the rotor current supply device corresponding to phase 2.

[0029] [Fig. 13]is a WW section of the rotor current supply device corresponding to phase 3.

[0030] [Fig. 14] is a NN section of the rotor current supply device corresponding to the neutral phase.

[0031] [Fig.15]is a view of the transmitter disc and its MM section.

[0032] [Fig. 16]is a view of the cooling air circulation in the rotor disc.

[0033] [Fig. 17]is a sectional view of the electric machine describing the re device liquid cooling of stators.

[0034] [Fig. 18]is a view of the circulation of cooling air of the rotor in the closed space of the electric machine.

[0035] [Fig. 1] is a front view of the discoid rotor 100 for an axial magnetic flux electric machine. This rotor comprises 2 flanges, the flange 110a is from the front in this view.

[0036] This flange has substantially trapezoidal openings 11a, the number of which is always a multiple of three but variable according to the performance required for the electrical machine. They each receive one of the ends of the magnetically conductive rotor cores 130, the other end being carried by the second rear flange.

[0037] We have a circular centering opening 112a which is used to position the rotor discoid 100 on its guide bearing.

[0038] On a first diameter, we have a series of drillings. These are the holes 113a for the passage of screws for fixing the discoid rotor 100 and the holes 114a for the passage of the pin contributing to the transmission of the torque.

[0039] On a second diameter we have circular zones 115a set back from the surface, of the same number as the rotor cores 130, occupied by the heads of the rivets 160 securing the two flanges.

[0040] On a slightly larger diameter, we have a series of inclined air inlet ducts 117a, from the air inlet 117al on the external surface of the flange 110a to the air outlet 117a2 on the internal surface (specified later). According to the inclination indicated in this figure, the air inlet ducts will only be effective for the direction of rotation 101. This direction of rotation, for an electric machine equipping a vehicle, must be that corresponding to forward motion.

[0041] Finally, on a diameter at the periphery, we have semi-circular zones 116a set back from the surface, of the same number as the rotor cores 130, occupied by the heads of the rivets 161.

[0042] These rivets 161 locally secure the two flanges with the peripheral strapping 120 on its internal protrusions 120a, narrower than the strapping itself and on which the two flanges are pressed (see [Fig.3]).

[0043] The role of this strapping 120, on which the flanges can be centered with radial tightening, is to significantly increase the resistance of the flanges to the centrifugal forces generated by the rotor cores 130 which each carry a coil and thus allow a higher limit rotation speed.

[0044] Air inlet ducts 117a mean air circulation internal to the discoid rotor 100. This circulation will be natural thanks to centrifugation during rotation and because the air outlet openings 121 are on the periphery in the ring 120 and facing each rotor core 130.

[0045] [Fig.2] is a front view of the discoid rotor 100 without the ring 120 and the flange 110a shown in [Fig.l]. This figure shows a view of the interior of the discoid rotor 100.

[0046] We see the internal face of the flange 110b, and find the same orifices, namely, a centering opening 112b which serves to position the discoid rotor 100 on its guide bearing, the holes for the passage of screws 113b for fixing the discoid rotor and holes for the passage of a pin 114b contributing to the transmission of the torque.

[0047] On a second diameter we have the holes 115b for the passage of the interior rivets 160 for securing the two flanges.

[0048] On a slightly larger diameter, we have a series of air ducts 117b inclined from the external air inlet 117b 1 to the internal air outlet 117b2 in line with the direction of rotation 101 (117b 1 ahead of 117b2).

[0049] The rotor cores 130 each carry a coil 140, each connected to two collectors: • to the collector 141 for phase U (1) by the end of the wire 140a of the winding and to the collector 144 for the neutral phase by the other end of the wire 140d; • to the collector 142 for phase V (2) by the end of the wire 140b of the winding and to the collector 144 for the neutral phase by the other end of the wire 140d; • to the collector 143 for phase W (3) by the end of the wire 140c of the winding and to the collector 144 for the neutral phase by the other end of the wire 140d.

[0050] Each coil produces an alternating magnetic field and the superposition of these fields gives a rotating resultant field which drives the rotor at the same speed, that is to say synchronous with that of the resultant field created by the rotor coils, because circulating in the axial magnetic fluxes, of constant orientations, generated by the stator pads.

[0051] These four collectors are connected to an external power supply by four wires: • the collector 141 for phase U (1) to the supply wire 151; • collector 142 for phase V (2) to supply wire 152; • the collector 143 for phase W (3) to the supply wire 153; • the collector 144 for the neutral phase to the supply wire 154; These supply wires 151,152,153,154 pass through the wall of the flange 110b.

[0052] Finally, on a diameter at the periphery, we have semi-circular withdrawal zones 116b relative to the external surface of the flange 110b, of the same number as the rotor cores 130, occupied by the heads of the rivets 161 (not shown).

[0053] [Fig.3] is the section AA of the discoid rotor 100. The two flanges 110a, 110b are joined and secured internally by the rivets 160. Externally, the rivets 161 secure the two flanges 110a, 110b with the strapping 120 at the level of each internal protrusion 120a.

[0054] The rotor core 130 passes through the two flanges and is flush externally. The coil 140 occupies the entire axial space of the annular chamber 110c formed by the flanges 110a, 110b.

[0055] the annular chamber 110c of the flanges extends towards the axis of rotation under the coils for the passage of the collectors 141, 142, 143 and 144.

[0056] Close to the inner diameter 110d of the annular chamber 110c, and facing the collectors, are the inclined air inlet ducts 117a and 117b, and in the ring 120 the air outlet opening 121 of width slightly less than that of the annular chamber 110c.

[0057] the rotor cores 130 are made of a material with the lowest possible reluctance, which must generate the least possible loss by eddy current. They can be of different compositions: SMC, a stack of thin sheets electrically insulated from each other and of several widths to form a figure close to a trapezoid, or a bundle of wires electrically insulated from each other and tangent to each other.

[0058] the rotor cores 130 have an overmolding 131 made of insulating material and with two different thicknesses. In the central zone the overmolding 131b is thicker and has two roles. The first is to axially block the core. Indeed, by having a perimeter larger than that of the substantially trapezoidal type openings 11a, 11b and having a length equal to the width of the annular chamber 110c, the overmolding 131b is blocked laterally on the flanges 110a and 110b and also blocks the core. The second role of this overmolding 131b is to serve as a cradle for the coil 140, this cradle being completed laterally by the flanges. At the ends 131a, the thickness of the overmolding gives the core the final dimension matching the trapezoidal type openings 11a and 111b.

[0059] [Fig.4] is the section BB of the discoid rotor 100. In the annular chamber 110c formed by the two flanges 110a, 110b and the ring 120 are installed, in the free zone under the coils, the circular collectors 141, 142, 143 and 144.

[0060] To the collector 144, the one with the smallest diameter, corresponding to the neutral phase, is welded the power supply wire 154 for connection with the external alternating current supply. This power supply wire 154 passes through the flange 110b through the opening 110b4 in the immediate vicinity of the internal diameter 110d of the annular chamber 110c.

[0061] To the collector 141, the one with the largest diameter, corresponding to phase 1 (U), is soldered the power supply wire 151 for connection with the external alternating current supply. This power supply wire 151 passes through the flange 110b through the opening 11 Obi in the immediate vicinity of the internal diameter 110d of the annular chamber 110c.

[0062] [Fig.5] is the section CC of the discoid rotor 100. It takes up many elements of the section AA. This section shows the connection of a coil 140 to the neutral collector 144 by soldering the end of the wire 140d. This section also shows the connection of the collector 142, corresponding to phase 2 (V), to the external power supply by means of the power supply wire 152. It passes through the flange 110b through the opening 110b2.

[0063] [Fig.6] is the section DD of the discoid rotor 100. This section shows the connection of a coil to the collector 141, corresponding to phase 1 (U) by soldering the end of the wire 140a. This section also shows the connection of another coil to the collector 143, corresponding to phase 3 (W) by soldering the end of the wire 140c.

[0064] The discoid rotor 100 is part of an electric machine 200 with magnetic flux axial comprising two stators 220 called left and 230 called right.

[0065] In [Fig.7], the stator 220 is constructed on the basis of a carcass 221 made of material composite. There are three main parts: • an outer crown 221e extending axially towards the rear; • an inner crown 221i also extending axially towards the rear; • a radial flat face 221r connecting the two crowns.

[0066] On the outer crown 221e we have different growths: • 221el corresponds to the fixing points on the central spacer 240 of the machine (see machine section [Fig.9]); • 221e2 corresponds to the positioning sleeves relative to the spacer 240 and the opposite carcass; • 221e3 and 221e4 correspond to the supply and evacuation of the liquid from cooling (see [Fig. 17]); • 221e5 corresponds to a trench, in the rear area of the outer crown 221e allowing a sealed crossing of the electrical conductors supplying the coils with direct current; • 221e6 corresponds to material removals from the front face, allowing the passage of cooling air from the rotor disk to the interior space of the electric machine 200 (see [Fig. 18]).

[0067] On the inner crown 221i we have different arrangements: • 221 it corresponds to the fixing points of the cover 228 (see [Fig.9] ) closing the coolant circulation chamber; • 221i2 corresponds to notches facilitating the circulation of air in a loop in the internal space of the electric machine (see [Fig. 18]); • 221i3 corresponds to areas of carcass lightening.

[0068] The radial face 221r connecting the outer 221e and inner crowns 221i appears in the form of sticks because this radial face has trapezoidal openings 221pl for receiving the stator pads 222. On the periphery of each trapezoidal opening 221pl, we have an extension 221p2 towards the rear which surrounds the stator pad 222 (stack of sheets 222f forming a trapezium). On the bases of the trapezium, longitudinal channels 221p3 which will be, during the assembly process, filled with glue 222a (see [Fig.9]) reinforce the connection of the stator pads 222 with the carcass 221, in addition to the bead of glue 222b around the head of the pad.

[0069] Around each stator pad 222, and carried by the extensions 221p2 towards the rear, there is a coil 223 which, when supplied with direct current, creates a magnetic field with an intensity proportional to the intensity of the electric current. The extensions 221p2 are externally the insulating supports of the coils 223.

[0070] Near the inner periphery of the outer ring 221e of the carcass, two closed and circular electric current collectors 224a, 224b (one masking the other in this view) are connected to the coils 223.

[0071] The coils 223 are of an even number and are supplied in parallel, each being connected to the collectors 224a, 224b by the two ends 223a and 223b of the wire of each coil.

[0072] To obtain magnetic fluxes of opposite direction between two adjacent coils, knowing that for all the coils the wire has the same winding direction, the connections of the ends 223a and 223b of the coil wires 223, with the collectors 224a and 224b must be such that two connections of the ends 223a are adjacent alternately with two connections of the adjacent ends 223b.

[0073] An external power supply (not shown) is connected to the collectors 224a, 224b by the wires 225a and 225b.

[0074] in [Fig. 8], the so-called right stator 230 is shown in front view. Its frame 231 is the mirror of that of the left stator 220 with one difference that there is an angular offset of a few degrees of the fixing points 231el on the spacer, so that the threads of the screws are not opposite each other, and that their length in engagement is sufficient without conditioning the thickness of the spacer. Indeed, we will see in the description of the electric machine (see [Fig. 9]) that the thickness of the spacer 240 is precisely equal to the sum of the thicknesses of the two air gaps 241 and of the discoid rotor 100.

[0075] For the rest, the description of the right stator 230 is similar to that of the left stator 220.

[0076] Thus the stator 230 is constructed on the basis of a carcass 231 made of composite material. There are three main parts: • an outer crown 231e extending axially towards the rear; • an inner crown 231i also extending axially towards the rear; • a flat radial face 23 Ir connecting the two crowns.

[0077] On the outer crown 231e we have different growths: • 231el corresponds to the fixing points on the central spacer 240 of the machine and which are subject to an angular offset with the 221el fixings; • 23le2 corresponds to the positioning sleeves relative to the spacer 240 and the opposite carcass 221; • 231e3 and 231e4 correspond to the supply and evacuation of the re liquid cooling (see [Fig. 17]); • 231e5 corresponds to a trench, in the rear area of the ex crown interior 231e allowing a sealed crossing of the electrical conductors 235a, 235b supplying the coils with direct current (see [Fig.9]); • 231e6 corresponds to material removals from the front face, allowing the passage of cooling air from the rotor disk to the interior space of the electric machine 200 (see [Fig. 18]).

[0078] On the inner crown 23 li we have different arrangements: • 231 it corresponds to the fixing points of the cover 239 (see [Fig.9] ) closing the coolant circulation chamber; • 231i2 corresponds to notches facilitating the circulation of air in a loop in the internal space of the electric machine (see [Fig. 18]); • 231i3 corresponds to areas of carcass lightening.

[0079] The radial face 23 Ir connecting the outer 231e and inner crowns 23 li appears in the form of sticks because this radial zone has trapezoidal openings 231pl for receiving the stator pads 232. On the periphery of each trapezoidal opening 231pl, we have an extension 231p2 towards the rear which surrounds the stator pad 232 (stack of sheets 232f forming a trapezium). On the bases of the trapezium, longitudinal channels 231p3 which will be, during the assembly process, filled with glue 232a (see [Fig.9]) reinforce the connection of the stator pads 232 with the carcass 231, in addition to the bead of glue 232b around the head of the pad.

[0080] Around each stator pad 232, and carried by the rearward extensions 231p2, is a coil 233 which, when supplied with direct current, creates a magnetic field with an intensity proportional to the intensity of the electric current.

[0081] Near the inner periphery of the outer ring 231e of the carcass, two closed and circular electric current collectors 234a, 234b, one masking the other in this view, are connected to the coils 233.

[0082] The coils 233 are of an even number and are supplied in parallel, each being connected to the collectors 234a, 234b by the ends 233a and 233b of the wire of each coil.

[0083] To obtain magnetic fluxes of opposite direction between two adjacent coils, knowing that for all the coils, the wire has the same winding direction, the connections of the ends 233a and 233b of the coil wires 233, with the collectors 234a and 234b must be such that two connections of the ends 223a are adjacent alternately with two connections of the adjacent ends 223b.

[0084] An external power supply (not shown) is connected to the collectors 234a, 234b by the conductive wires 235a and 235b.

[0085] [Fig.9] is a sectional view of the axial magnetic flux electric machine 200, equipped with the wound disc rotor 100. It is contained in the casing 210 closed by the closing flange 211 fixed to the casing using the screws 212.

[0086] The discoid rotor 100 is framed by the stators 220, 230. The section of the left stator 220 is according to the line AA of [Fig.7]. The section of the right stator 230 is according to the line BB of [Fig.8].

[0087] The stators 220,230 are constructed on the basis of a frame 221,231 provided with a series of openings bordered by an axial extension 221p2,231p2, towards the rear, for receiving the stator pads 222,232.

[0088] The stator pads are glued along their entire length in the channels 221p3 and 231p3 and on the front periphery by the cords 222b, 232b.

[0089] Externally, these axial extensions 221p2,231p2 carry the coils 223,233.

[0090] The magnetic circuit is looped behind the stator pads 222,232 by the annular yokes 227,237 made of rolled sheet metal and glued to the stator pads 222,232.

[0091] The frames 221, 231 with axial extensions in outer rings 221e, 23 le and inner rings 221i, 231i, with an annular radial face 221r, 231r whose openings 221pl, 231pl are obstructed by the stator pads 222, 232 form hollow annular volumes closed by the annular covers 228, 238. These sealed stator chambers 221v, 231v are occupied by the stator pads 222, 232, the coils 223, 233 and the yokes 224, 234 and the remaining free space allows the circulation of a cooling liquid which will be in direct contact with the coils and the yokes.

[0092] The coils 223, 233 are supplied with direct current. The two ends of the wire 223a, 223b and 233a, 233b are in contact (welded) respectively with the collectors 224a, 224b and 234a, 234b. On the right stator 230, the conductive wires 235a and 235b for connection with the external direct current supply appear. An elastomer pad 236 allows the two conductive wires 235a and 235b to pass through the outer ring 231e in a sealed manner. On the stator 220, we have the same device but not shown.

[0093] The covers 228, 238 are fixed on their internal diameter by the screws 229 (not shown), 239 and on their external diameter by the screws 243, a means of fixing common with the carcasses 221, 231 of the stators on the central spacer 240.

[0094] This central annular spacer 240 is the intermediate element between the stators 220, 230 and the casing 210. On the periphery it has several ears 240a crossed by the screws 242 for placement on the support surfaces 210a.

[0095] In the inner zone of this annular central spacer 240, the discoid rotor 100 is arranged. It carries on either side and at a precise distance the two stators 220, 230. The thickness of the spacer 240 is precisely equal to the sum of the thicknesses of the discoid rotor 100 and the two air gaps 241.

[0096] Between two consecutive ears 240a, the spacer 240 is set back relative to the casing fabric 210 and provides a passage for air circulation in the unoccupied internal spaces 214, formed by the casing 210 and the closing flange 211.

[0097] The casing 210 has a general shape close to a slightly conical cylinder. (foundry draft) closed on one side by a 210b canvas. In the center of this canvas, in the boss 210c, an axis 250 is fitted, without play.

[0098] On its free part extending beyond the boss 210c, the axis 250 carries a bearing 260 with double rows of angular contact balls.

[0099] This bearing 260 consists of an outer ring 261, two inner rings 262, 263 between which the balls 264 are interposed. The inner rings 262, 263 are pressed into contact with each other. This bearing 260 is characterized by an absence of internal play and a slight preload. The ring 263 is indirectly in axial support on the boss 210c, because between the latter and the ring 263 is interposed the balancing washer 270 of the air gaps 241. The whole is held tight by the screw 252 and the pressure washer 251.

[0100] The outer ring 261 has an annular radial extension 261a. On one side of this is supported the discoid rotor 100, centered on the outer diameter. On the opposite side, the device for supplying the rotor with electric current 300 is arranged, secured by the screws 301.

[0101] Against the discoid rotor 100 is supported a power transmission hub 280, also centered on the outside diameter of the ring 261 of the bearing 260. The screws 285 pass through the radial extension 261a, the discoid rotor 100 and secure them with the power transmission hub 280.

[0102] The power transmission hub 280 externally carries the rotor 291 of the resolver, the stator 290 of which is positioned on the closing flange 211. In its hollow part, the power transmission hub 280 accommodates the grounding device 287, protecting the bearing 260 from possible parasitic currents, and a ball slide 282 provided with a grooved ring 281, protecting the machine from external axial stresses harmful to the stability of the air gaps 241.

[0103] [Fig. 10] is a sectional view of the electric current supply device 300.

[0104] This device is composed of several elements, some of which are mobile in rotation and others fixed, because its role is to transmit electric current from a three-phase power supply (not shown) external to the electric machine 200 to its discoid rotor 100 which is rotating by definition.

[0105] The entire device is installed on a metal support 310 centered by its diameter 310a and is supported by its face 310b on the radial extension 261a of the outer ring 261 of the bearing 260.

[0106] The support 310 has a tubular shape 310c. Externally, grooves 310d are cut which drive the rotating elements of this feed device, and near the end, a groove 310e is cut for receiving a stop ring.

[0107] Carried by the groove, are stacked from right to left: • a first rotating element 320 in the form of an annular disc, made of material insulating, and with a grooved inner diameter; • A second rotating element 330, made of insulating material, with an end in the form of an annular disc and an externally grooved tubular part 330a. • A third rotating element 340, made of insulating material, carried by the second 330, in the form of an annular disc with a grooved internal diameter and whose section is T-shaped. • A fourth rotating element 350, made of insulating material, carried by the second 330, in the form of an annular disc with a grooved internal diameter and of any shape.

[0108] In the first element 320 are cut several radial grooves. [Fig. 10] is the section of the phase 2 power supply device. The groove 320v houses the tab 341v attached to the power supply wire 152 connected to the collector 142.

[0109] In the annular part of the second rotary element 330 is fixed a crown-shaped plate 331 made of conductive material, copper or copper alloy, integral in rotation.

[0110] On either side of the third rotary element 340 are fixed two crown-shaped plates 341, 342 identical to the crown-shaped plate 331, made of conductive material, copper or copper alloy, and integral in rotation.

[0111] Similarly, in the fourth rotating element 350 is fixed a crown-shaped plate 351 identical to the previous ones, made of copper or copper alloy, integral in rotation.

[0112] Between the second 330 and the third 340 rotating element a first fixed element 360, made of insulating material, is arranged.

[0113] Between the third 340 and the fourth 350 rotating element a second fixed element 370, made of insulating material, is arranged.

[0114] These two fixed elements 360,370 in the form of an annular disc, made of insulating material, are centered on the tubular part 330a of the second rotary element 330.

[0115] These two fixed elements 360,370 each have a protrusion 360a,370a, which cooperate with a pin 217, for locking in rotation, screwed into the casing 210 of the electric machine.

[0116] These two fixed elements 360,370 each carry on either side of the central insulating core a crown-shaped plate made of conductive material identical to those fixed to the rotating discs.

[0117] The central core of the fixed element 360 is framed by the integral crown-shaped plates 361, 362.

[0118] The central core of the second fixed element 370 is framed by the crown-shaped plates 371, 372.

[0119] In summary, we are in the presence of: • three support elements made of insulating material, 330, 340, 350 mobile in rotation carrying four crown-shaped plates, made of conductive material 331 for the first, 341 and 342 for the second and 351 for the third, for the three phases and the neutral; • Two fixed support elements made of insulating material, 360,370 locked in rotation and carrying four crown-shaped plates, made of conductive material, 361,362 for the first 360 and 371,372 for the second 370 for the three phases and the neutral.

[0120] Opposite each rotating crown-shaped plate 331, 341, 342, 351 is located, respectively, a rotationally locked crown-shaped plate 361, 362, 371, 372.

[0121] To transmit the electric current from the external power supply to the rotor, electrical contact must be established between the pairs of plates facing each other.

[0122] Also, between the two crown-shaped plates 331, 361 then 362, 341 then 342, 371 and 372, 351 are interposed four transmitter discs 380 centered on their external diameter, the first in the second rotating element 330, the second and third in the third rotating element 340 and the fourth in the fourth rotating element 350.

[0123] These four transmitting discs 380, see [Fig. 15], are similar to those of the needle thrust bearings, but play a very different role. They are composed of an annular disc 381 made of insulating material which has, on two concentric circles, a large number of rectangular openings in which are inserted rollers 382, cylindrical and all identical, made of conductive material, copper or copper alloy, with a diameter greater than the thickness of the annular disc 381.

[0124] The choice of a very large number of rollers 382 is the way of splitting the electric current and limiting it, for each contact, to a low intensity level reducing the risks of electric arcing and damage.

[0125] These rollers are subjected to a very low axial load which ensures contact, for the transmission of the electric current, of the greatest possible proportion of rollers 382 with the crown-shaped plates from 361 to 331 then from 362 to 341 then from 371 to 342 and from 372 to 351.

[0126] For this, the rotating elements 350, 340, 330, 320, the fixed elements 360, 370 and the four transmitting discs 380 are pressed against each other and against the support element 310 by a wave washer type spring 390 arranged in a circular groove 350b of the fourth complementary rotating element 350, put under tension by the washer 391 held by the stop ring 392 engaged in the groove 310e of the support 310.

[0127] Each crown-shaped plate has a connection tab either with the rotor coils or with the external power supply.

[0128] In [Fig. 10] the connections correspond to phase 2. The rotating crown-shaped plate 341 has a tongue 341v. It passes under the first fixed element 360 in an axial groove 330v of the element 330, crosses the radial zone of the second element 330 in an opening 330vl, then is bent and takes a radial direction in the groove 320v and will connect to the supply wire 152 connected to the collector 142. The crown-shaped plate 362 carried by the first fixed element 360, separated from the crown-shaped plate 341 by a transmitter disc 380, has a tongue 362v which leaves the electric machine by the tongue guide 395 made of insulating material engaged in the opening 215 of the casing 210 and retained by the stop ring 216.

[0129] To ensure the longevity of the electrical power supply device 300, the rollers 382 will be coated with conductive bearing grease. This grease will be kept confined by the felt seals 396 closing the spaces between the fixed elements and the rotating elements.

[0130] [Fig. 11] is a UU sectional view of the electric current supply device 300 according to phase 1. The fixed crown-shaped plate 361 is supplied by the tab 36lu connected to the external power supply. Between the fixed crown-shaped plate 361 and the rotating crown-shaped plate 331, a transmitter disc 380 is interposed. The rotating crown-shaped plate 331 supplies the discoid rotor wound by the tab 33lu.

[0131] [Fig.12] is a sectional view VV of the electric current supply device 300 according to phase 2 (see also paragraph

[0129] ). The fixed crown-shaped plate 362 is supplied by the tab 362v connected to the external power supply. Between the fixed crown-shaped plate 362 and the rotating crown-shaped plate 341, a transmitter disc 380 is interposed. The rotating crown-shaped plate 341 supplies the discoid rotor wound by the tab 34Iv which passes under the first fixed element 360 in an axial groove 330v of the tubular element 330a, then is bent and takes a radial direction in the groove 320v.

[0132] [Fig. 13] is a sectional view WW of the electric current supply device 300 according to phase 3. The fixed crown-shaped plate 371 is supplied by the tongue 37Iw connected to the external power supply. Between the fixed crown-shaped plate 371 and the rotating crown-shaped plate 342, a transmitter disc 380 is interposed. The rotating crown-shaped plate 342 supplies the wound disc rotor by the connecting tongue 342w which passes under the first fixed element 360 in an axial groove 330w of the tubular element 330a, then is bent and takes a radial direction in the groove 320w.

[0133] [Fig. 14] is a sectional view NN of the electric current supply device 300 according to the neutral phase. The fixed crown-shaped plate 372 is supplied by the tab 372n connected to the external power supply. Between the fixed crown-shaped plate 372 and the rotating crown-shaped plate 351, a transmitter disc 380 is interposed. The rotating crown-shaped plate 351 supplies the wound disc rotor by the connection tab 35 In which passes under the fixed elements 370, 360 in an axial groove 330nd of the tubular element 330a, then is bent and takes a radial direction in the groove 320n.

[0134] [Fig. 15] is the presentation of the transmitter disc 380. See the description paragraph

[0123] .

[0135] [Fig. 16], is a partial front view of the discoid rotor 100. On the flange 110a, below each coil 140, that is to say the part closest to the axis of rotation we have an air inlet duct 117a inclined relative to the axis of rotation of the discoid rotor 100. This bore is an air circulation duct between the unoccupied volume internal to the casing and the unoccupied volume internal to the annular chamber 110c. For the direction of rotation 101 indicated, the introduction of air towards the annular chamber 110c is favored by an air inlet 117a 1, in relation to the internal volume of the casing, angularly in advance of the air outlet 117a2, in relation to the internal volume of the annular chamber 110c. The air outlet 117a2 is centered relative to the coil 140.

[0136] In the hoop 120, the air outlet openings 121 are, conversely, an air circulation duct from the annular chamber 110c to the volume internal to the casing, the openings are centered relative to the coils 140.

[0137] Arranged in this way, the circulation of air between the air inlets 117a, 117b and the air outlet 121 of the annular chamber 110c is as follows: • suction through the air inlets 117a 1,117b 1 and expulsion through the air outlets 117a2,l 17b2 of the air inlet ducts 117a, 117b inclined along the path 118a; • the incoming flows are shared at the bottom of the coils 140, equally or not, and bypass them according to the paths 118b 1, 118b2; • the two flows come together at the top of each coil and exit the annular chamber 110c through the air outlet opening 121 along the path 118c.

[0138] [Fig. 17], shows in section the electric machine 200 according to the defined CC sections on [Fig.7] and [Fig.8].

[0139] The device for cooling the stators 220, 230 by circulation of a liquid fluid, in the stator chambers 22 Iv and 23 Iv is presented because it also participates in the cooling of the ambient air in the internal spaces 214 in communication with each other, of the casing 210 and of the closing flange 211 of the machine 200, and not occupied.

[0140] The cooling fluid supply ducts 244a and 244e are attached to the central spacer 240. As shown in sections CC of [Fig.7] and [Fig.8], these ducts are arranged as follows: the supply duct 244a is close to the highest zone of the electrical machine 200 and the evacuation duct 244e is close to the lowest zone and they are diametrically opposed.

[0141] These angled conduits enter the machine by passing through an elastomer block 213 housed in a suitable opening 210d of the casing, blocked by the closing flange 211.

[0142] The supply duct 244a communicates with the radial duct 245a, sealed by the cover 246. The seal between the spacer plate 240 with the left 221 and right 231 carcasses is ensured by the O-rings 247.

[0143] The radial duct 245a opens onto two axial ducts 221e7 and 231e7 which supply the stator chambers 221 v and 23 Iv of the stators via the openings 221e8 and 231e8 at the ends of the axial outer rings 221e and 231e of the carcasses.

[0144] The coolant circulates in the stator chambers 221 v and 23Iv and absorbs the calories released by the Joule effect in the coils and the eddy currents in the stator cores and the yokes.

[0145] The coolant is also in contact with the covers 228, 238 which externally carry radial fins 228a, 238a in contact with the ambient air of the unoccupied internal spaces 214 of the machine 200 and is thus able to take calories from this ambient air. This is the reason for the presentation of the stator cooling device which indirectly contributes to the cooling of the discoid rotor 100.

[0146] The emptying of the stator chambers 221 v and right 23Iv is carried out in a similar manner to the supply via the communication openings 221e9, 231e9, then via the axial conduits 221el0, 231el0, which join in the single radial conduit 245e, obstructed by the cover 246 and finally via the elbow conduit 244e which passes through the elastomer block 213, housed in an opening 210d of the casing, held by the closing flange 211.

[0147] [Fig. 18], is a sectional view of the electrical machine 200 showing the loop circulation of air in the closed space 214 constituted by the casing 210 and the closing flange 211.

[0148] The cooling of the air passing inside the discoid rotor 100 is obtained by a double heat exchange: • with the ambient air outside the machine 200 along the canvases of the casing 210 and the closing flange 211; • with the coolant from the stators 220,230 along the fins radials 228a,238a of the covers 228,238 of the carcasses 221,231.

[0149] The air expelled from the annular chamber 110c of the discoid rotor 100, through the air outlet openings 121 along the path 118c, makes the following symmetrical loops: • along the paths 214a, is divided into two flows; • according to the routes 214b, crosses the carcasses 221,231 in material withdrawals 221e6,231e6; • according to the paths 214c, bypasses the stators 220,230 between the periphery of the stators and the casing fabric 210; • according to the paths 214d, heads towards the center of the machine 200 along, on the left, the radial fins 228a of the cover 228 and the casing fabric 210 and on the right the radial fins 238a of the cover 238 and the fabric of the closing flange 211; • according to the routes 214e, bypasses the stators 220,230 in their internal openings; • is re-sucked, along path 118a through the air inlets 117al,l 17b 1 of the discoid rotor 1.

[0150] During the paths 214d, the stator cooling device 220, 230 therefore participates in the cooling of the air circulating in the annular chamber 110c of the discoid rotor 100.

Claims

1. Claims Axial magnetic flux electric machine (200) consisting of: • a central discoid rotor (100) with a structure composed mainly of two flanges (110a, 110b) made of composite material and a peripheral steel ring 120 together forming an annular chamber 110c. The two flanges support rotor cores (130) generating a magnetic field, a multiple of three in number and each surrounded by a coil (140). In the annular chamber (110c), under the coils, the electrical collectors (141, 142, 143, 144) are arranged. Lateral air inlets (117a, 117b) in the annular chamber 110c and radial air outlets (121) in the peripheral ring (120) allow, when the rotor is rotating, a natural circulation of air for cooling the coils; • two lateral stators (220,230) constructed on the basis of a frame (221,231) made of composite material, comprising an outer ring (221e,231e), an inner ring (221i,231i), a radial face (221r,231r) whose trapezoidal openings accommodate the stator pads (222,232), a multiple of two in number, separated from the rotor (100) by the air gaps (241). They are connected to each other, at the rear end, by a yoke (227,237) looping the magnetic field. Each pad carries a coil (223,233). They are supplied with direct current by closed circular collectors (224a, 224b, 234a, 234b) arranged inside the frames (221, 231) close to the outer ring (221e, 231e). The frame (221, 231) is closed, opposite its radial face, by a cover (228, 238). Frame and cover form a sealed stator chamber (221v, 231v) in which a cooling fluid circulates; • a device (300) for supplying the rotor with electric current comprising rotating elements (320, 330, 340, 350) made of insulating material carrying crown-shaped plates (331, 341, 342, 351) made of conductive material and each having a tab (331u, 341v, 342w, 351n) for connection to the collectors (141, 142, 143, 144) by the supply wires (151,152,153,154), fixed elements (360,370) made of insulating material carrying crown-shaped plates (361,362,371,372) and each having a tab (361u,362v,371w,372n) for connection to the external power supply, current transmitting discs (380) interposed between the rotating crown-shaped plates and the fixed crown-shaped plates, characterized in that: • the rotor coils (100) are supplied with three-phase alternating current via the power supply device (300), at variable frequency, which allows the rotation speed of the electric machine to be controlled. • The stator is supplied with direct current which allows the electric machine to be controlled in torque and power.

2. Axial magnetic flux electric machine (200) characterized in that in the rotor (100), one coil (140) out of three is connected to the collector (141) corresponding to phase 1, to the collector (142) corresponding to phase 2, to the collector (143) corresponding to phase 3, and all the coils are connected to the collector 4 corresponding to the neutral. The coils of the same phase are connected in parallel.

3. An axial magnetic flux electric machine (200) characterized in that the stator coils (223, 233) are connected as follows: the ends of the wires (223a) are connected in parallel to the collector (224a), the ends of the wires (223b) are connected to the collector (224b). Similarly, the ends of the wires (233a) are connected to the collector (234a), the ends of the wires (233b) are connected to the collector (234b). In order to obtain that two adjacent coils deliver reversed magnetic fields, because the winding direction of the wire is identical, it is necessary that two ends 223a are alternately adjacent with two ends 223b and, likewise, two ends 233a are also alternately adjacent with two ends 233b.

4. Axial magnetic flux electric machine (200) characterized in that two facing stator pads, one belonging to the left stator (220) and the other to the right stator (230), are connected in in order to obtain two magnetic fluxes in the same direction.

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