Stator and rotating polyphase electrical machine with axial electromagnetic flux

Abstract

Stator (1) of a rotating, multiphase, axially electromagnetic flux electric machine (100) comprising: - a stator yoke (2), - at least one first series of support teeth (3), - a plurality of coils (4) mounted around a respective support tooth (3) of the first series, - at least one first series of phase-shifting teeth (5), the support and phase-shifting teeth (3, 5) of the first series being assembled on a first face of the stator yoke (2), the support teeth (3) being distributed in single-phase sections (Q1, Q2, Q3, Q4, Q5, Q6), a phase-shifting tooth (5) being interposed between the adjacent single-phase sections (Q1, Q2, Q3, Q4, Q5, Q6). Figure 4

Description

Title of the invention: Stator and polyphase rotating electric machine with axial electromagnetic flux Technical field of the invention

[0001] The present invention relates to a stator and a polyphase rotating electrical machine with axial electromagnetic flux. The invention also relates to a method of assembling a stator of a polyphase rotating electrical machine with axial electromagnetic flux. Technical background

[0002] A polyphase rotating electrical machine is known from the prior art, used for example to convert electrical energy into mechanical energy in order to drive a motor vehicle. Conventionally, a rotating electrical machine is of the type either with axial electromagnetic flux or with radial electromagnetic flux.

[0003] The need to increase the electrical / mechanical power density developed by electrical machines has continued to increase in recent years with growing interest in discoidal machines, also known as axial machines. In certain applications, these machines are very competitive compared to their radial counterparts. They nevertheless remain more complicated, on the one hand, to manufacture and, on the other hand, to manufacture in a reproducible manner. In particular, the mechanical bending of the rotors often prevents the reduction of magnetic air gaps, which, for the same power developed, requires a higher number of ampere turns. These drawbacks push designers of axial machines wishing to increase power density towards solutions with a very low filling coefficient. This is particularly marked for high voltage applications, where the associated phenomena must be controlled. Summary of the invention

[0004] One of the aims of the present invention is to propose a stator for a polyphase rotating electrical machine with axial electromagnetic flux, a polyphase rotating electrical machine with axial electromagnetic flux and a method for assembling a stator for a polyphase rotating electrical machine with axial electromagnetic flux, making it possible to at least partially resolve the drawbacks of the prior art.

[0005] To this end, the invention relates to a stator of a polyphase rotating electrical machine with axial electromagnetic flux comprising: - a stator head, - at least a first series of support teeth, - a plurality of coils mounted around a respective support tooth of the first series, characterized in that it comprises: - at least a first series of phase shift teeth, the support and phase shift teeth of the first series being assembled on a first face of the stator yoke, the support teeth being distributed in single-phase quarters, a phase shift tooth being interposed between the adjacent single-phase quarters.

[0006] This assembly of the support and phase shift teeth to the stator yoke, associated with a winding by single-phase quarters, makes it possible to increase the filling coefficient, which allows control of the extraction of the calories generated while guaranteeing optimal electrical insulation. With this configuration where the winding is concentrated on support teeth distributed in single-phase quarters, the compactness of the electrical machine is increased and its repeatability of industrial manufacturing on a large scale is guaranteed, while controlling the performance under load. Furthermore, the number of welds is reduced. In addition, this architecture makes it possible to integrate cooling as close as possible to the coil ends, which makes it possible to achieve high linear loads. Finally, adaptation to higher voltage levels is facilitated by this distribution of the winding.

[0007] The stator may further comprise one or more of the features described below, taken alone or in combination.

[0008] The stator may comprise: - a second series of support teeth, - a plurality of coils mounted around a respective support tooth of the second series, - a second series of phase shift teeth, the support and phase shift teeth of the second series being assembled on a second face of the stator yoke axially opposite the first face, the support teeth being distributed in single-phase quarters, a phase shift tooth being interposed between the adjacent single-phase quarters.

[0009] According to an exemplary embodiment, the support teeth of the first and second series are axially superimposed on each other two by two, heads of the support teeth being in contact in first radial openings of the stator yoke. In other words, there is a straight line parallel to the axis of the stator passing both through the head of the support teeth of the first series and through the head of the support teeth of the second series.

[0010] The support teeth of the first and second series axially superimposed on each other two by two can be fixed to each other or made in a single piece.

[0011] According to an exemplary embodiment, the phase shift teeth of the first and second series are axially superimposed on each other two by two, heads of the phase shift teeth being in contact in second radial openings of the stator yoke.

[0012] The phase shift teeth of the first and second series axially superimposed on each other two by two can be fixed to each other or made in a single piece.

[0013] According to an exemplary embodiment, a head of each support tooth cooperates by a tenon-mortise assembly with a respective complementary assembly form provided in first radial openings of the stator yoke.

[0014] For example, the head of the support teeth has two rectilinear grooves extending on a respective side of the head, the complementary assembly shape being achieved by two complementary rectilinear ribs extending radially in the first radial openings of the stator yoke.

[0015] According to other examples of tenon-mortise assembly, the tenon has a dovetail or fir-foot male and the mortise has a complementary shape.

[0016] According to an exemplary embodiment, a head of each phase shift tooth cooperates by a tenon-mortise assembly with a respective complementary assembly form provided in second radial openings of the stator yoke.

[0017] According to an exemplary embodiment, an isthmus of each support tooth and phase shift tooth intended to face a rotor, opposite the head, has a fin extending beyond the tooth body.

[0018] According to an exemplary embodiment, the head of the support teeth is less wide or of the same width as the tooth body so that the coils can be inserted axially onto a respective support tooth through the head. The width is measured in the circumferential direction.

[0019] The stator may include a cooling device.

[0020] The cooling device may comprise a first and / or second internal circuit surrounding an internal radial periphery of the stator yoke, the first and / or second internal circuit passing through at least one phase shift tooth head.

[0021] More precisely, for example, the first and second internal circuits comprise a respective tubular ring, coaxial with the stator yoke, axially facing the coil leads located on the side closest to the axis. The tubular ring is radially interposed on a disc of the stator yoke between the ends of the support teeth and a central cylinder of the stator yoke.

[0022] The first and second internal circuits also have at least one fluid supply, respective or common to the two internal circuits, connected to the tubular ring, passing through the head of a phase shift tooth.

[0023] According to a first exemplary embodiment, the first and / or second internal circuit has at least one fluid outlet respective or common to the two circuits. internal, connected to the tubular ring, passing through the head of a phase shift tooth. In this embodiment, the fluid enters through the at least one fluid inlet and exits through the at least one fluid outlet. The fluid circulates in a closed circuit in the first and / or second circuit which cools the coil ends by conduction of the circuit walls. The fluid is, for example, water.

[0024] According to a second exemplary embodiment, the tubular ring of the first and second internal circuits respectively comprises at least one ejection hole, for example a plurality of ejection holes, arranged on the side of the tubular ring facing the coil ends. In this exemplary embodiment, the fluid enters through the at least one fluid inlet and exits through the at least one ejection hole. The fluid circulates in an open circuit; it is ejected from the first and / or second circuit to cool the coil ends. The fluid can be any electrically insulating and heat-transferring liquid, making it possible to cool a component, such as oil.

[0025] The cooling device may comprise an external circuit surrounding the external radial periphery of the stator yoke while being held by ends of the stator yoke.

[0026] More precisely, for example, the external circuit comprises a tubular ring, coaxial with the stator yoke, axially facing the coil ends located on the side furthest from the axis. The tubular ring is, for example, inserted into a peripheral end groove formed in the ends of the branches of the stator yoke. The external circuit also has at least one fluid supply connected to the tubular ring.

[0027] According to a first exemplary embodiment, the external circuit has at least one fluid outlet connected to the tubular ring. In this exemplary embodiment, the fluid enters through the at least one fluid inlet and exits through the at least one fluid outlet. The fluid circulates in a closed circuit in the external circuit which cools the coil ends by conduction of the circuit walls. The fluid is for example water.

[0028] According to a second exemplary embodiment, the tubular ring of the external circuit comprises at least one ejection hole, for example a plurality of ejection holes, arranged on each side of the tubular ring facing the coil ends of the first and second series where appropriate. In this exemplary embodiment, the fluid enters through the at least one fluid inlet and exits through the at least one ejection hole. The fluid circulates in an open circuit; it is ejected from the external circuit to cool the coil ends. The fluid can be any electrically insulating and heat-transferring liquid, making it possible to cool a component, such as oil.

[0029] In the case where the electrical machine comprises a cooling device having at least one internal circuit and / or one external circuit, in open circuit, a An oil return channel may be provided in at least one branch of the stator head separating two first radial openings, the stator head being made in two parts which fit together axially. The channels provided in the branches may communicate with a common cylindrical conduit provided in a central cylinder of the stator head closed at the axial ends.

[0030] The invention also relates to a polyphase rotating electrical machine with axial electromagnetic flux comprising at least one rotor, characterized in that it comprises at least one stator as described above.

[0031] The invention also relates to a method of assembling a stator of a polyphase rotating electrical machine with axial electromagnetic flux as described above, in which: - the coils are inserted axially onto a respective support tooth by passing the coils through the head of the support teeth, - then, the heads of the support teeth are assembled in first radial openings of the stator yoke and the heads of the phase shift teeth in second radial openings.

[0032] The assembly method may further comprise one or more of the features described below, taken alone or in combination.

[0033] A first and / or a second internal circuit of a cooling device can be mounted around a central cylinder of the stator yoke before assembling the support and phase shift teeth and passing at least one fluid supply of the first and / or second internal circuit through at least one phase shift tooth.

[0034] An external circuit of a cooling device can be mounted on the ends of the stator yoke once all the support and phase shift teeth are assembled to the stator yoke. Brief description of the figures

[0035] Other advantages and characteristics will appear on reading the following description of a particular embodiment of the invention, but in no way limiting, as well as the appended drawings in which:

[0036] [Fig-1] is a perspective view of a first example of an embodiment of a polyphase rotating electrical machine with axial electromagnetic flux.

[0037] [Fig.2] shows an exploded view of the electric machine of [Fig.l] without casing.

[0038] [Fig.3] shows the electric machine of [Fig.2] in the assembled state.

[0039] [Fig.4] shows the electric machine of [Fig.3] without rotors.

[0040] [Fig.5] shows a schematic view of an example of wiring of the coils of the electric machine of [Fig.l].

[0041] [Fig.6] shows a stator yoke of the electric machine of [Fig.l].

[0042] [Fig.7] shows a perspective view of a supporting tooth of the electric machine of [Fig.l].

[0043] [Fig.8] shows a perspective view of the support tooth of [Fig.7] around which a coil is mounted.

[0044] [Fig.9] shows a perspective view of a phase shift tooth of the electric machine of [Fig.l].

[0045] [Fig. 10] shows a perspective view of two phase shift teeth of [Fig.9] superimposed.

[0046] [Fig. 11] shows a perspective view of the stator yoke of [Fig.6] assembled with the support teeth and the phase shift teeth.

[0047] [Fig. 12] shows a perspective view of the stator yoke of [Fig.6] assembled to a cooling device.

[0048] [Fig. 13] shows elements of a second example of the stator of the electric machine.

[0049] [Fig. 14] shows elements of a third example of the stator of the electric machine, in the assembled state.

[0050] [Fig. 15] shows the stator yoke of the stator of [Fig. 14] in the disassembled state.

[0051] [Fig. 16] shows an exploded view of a fourth example of machine embodiment electric.

[0052] [Fig. 17] shows elements of the electric machine of [Fig. 16] in the assembled state.

[0053] In these figures, identical elements have the same reference numbers.

[0054] For the sake of clarity, the coils are shown schematically in these figures by simplified elements. However, a more realistic example of a coil is shown in [Fig.8]. Detailed description

[0055] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Single features of different embodiments may also be combined or interchanged to provide other embodiments.

[0056] [Fig.l] shows a first example of embodiment of a polyphase rotating electrical machine 100 with axial electromagnetic flux, synchronous, of high frequency, such as between 1kHz and 3kHz, which can be used as an electric motor or generator.

[0057] As visible in Figures 2 and 3, the electrical machine 100 comprises at least one rotor 200, 300 and at least one stator 1, each having a general shape annular, the rings being axially opposite each other and separated by an air gap.

[0058] The rotor 200, 300 has coils or permanent magnets, here twenty-six permanent magnets 201, 301, for example surface-mounted on a support ring 202, 302 of the rotor 200, 300 or buried in the latter, the coils or permanent magnets facing the stator 1 ([Fig.3]).

[0059] The electrical machine 100 may comprise several subassemblies of rotors and stators succeeding one another alternately in the axial direction. In the example illustrated, the electrical machine 100 has a first rotor 200, a second rotor 300 and a stator 1 axially interposed between the first and second rotors 200, 300. When the electrical machine 100 comprises a rotor interposed between two stators, the opposite faces of the rotor may each carry coils or permanent magnets facing a respective stator.

[0060] The stator 1 comprises a stator yoke 2, a plurality of coils 4, at least a first series of support teeth 3 and at least a first series of phase shift teeth 5. In the case of an electrical machine 100 comprising a stator 1 interposed axially between two rotors 200, 300, the stator 1 may comprise a second series of support teeth 3 and a second series of phase shift teeth 5.

[0061] The support and phase shift teeth 3, 5 of the first series are assembled on a first face of the stator yoke 2 opposite the coils or permanent magnets 201 of the first rotor 200. Where appropriate, the support and phase shift teeth 3, 5 of the second series are assembled on a second face of the stator yoke 2 axially opposite the first face, opposite the coils or permanent magnets 301 of the second rotor 300.

[0062] The assembly of the support and phase shift teeth 3, 5 to the stator yoke 2 can be removable.

[0063] The stator yoke 2 has for example a central cylinder 14 and a plurality of radial openings 6, 7 separated by branches 10 of the stator yoke 2 extending radially from the central cylinder 14, for example from its middle ([Fig.6]). The stator yoke 2 and the rotors 200, 300 are coaxial, that is to say their axes are coincident. The stator yoke 2 is magnetic or not and preferably massive.

[0064] The support teeth 3 of the first and second series may be axially superimposed on each other two by two in a symmetrical manner, the heads 8 (also called "tooth bases") of the support teeth 3 being in contact in first radial openings 6 of the stator yoke 2 ([Fig. 11]). Similarly, the phase shift teeth 5 of the first and second series may be axially superimposed on each other two by two in a symmetrical manner, the heads 11 (also called "tooth bases") of the phase shift teeth 5 being in contact in second openings radials 7 of the stator yoke 2 (figures 10 and 11).

[0065] The stator 1 has a predetermined number N of phases. In the present embodiment, the stator 1 is three-phase, that is to say it has three phases.

[0066] The coils 4 are for example multi-stranded, for example composed of twenty-one flat conductors connected in series and insulated from each other by electrical insulation. A plurality of coils 4 are mounted around a respective support tooth 3 of the first series, and if necessary a plurality of coils 4 are mounted around a support tooth 3 of the second series. The conductors of the coils 4 may first be wound around a support, for example plastic, the coil 4 then being inserted axially onto a respective support tooth 3 of the first and second series if necessary. Two support teeth 3 out of three of each series are for example provided with a coil 4, a support tooth 3 without a coil being interposed between two support teeth 3 with a coil ([Fig.4]). Other embodiments are possible on the number of support teeth 3 provided or not with coils.

[0067] The support teeth 3 and the coils 4 of the first series, and of the second series if applicable, are distributed in single-phase quarters Q1, Q2, Q3, Q4, Q5, Q6, a phase-shifting tooth 5 being interposed between the adjacent single-phase quarters ([Fig.4]). Each coil 4 belongs to a single-phase quarter of one of the N phases of the stator 1.

[0068] The single-phase quarters Ql, Q2, Q3, Q4, Q5, Q6 are offset by a geometric angle equivalent to the electrical phase shift imposed by the number of phases. The dimension of the phase shift teeth 5 is determined so that the single-phase quarters Ql, Q2, Q3, Q4, Q5, Q6 are phase-shifted from each other by this geometric angle.

[0069] Furthermore, the equivalent electrical phase shift angle between two notches (space between the teeth for the winding), respectively of the last coil 4 of the district Qi and the first of the district Qi+1 which follows, equal to a multiple of the electrical phase shift angle. For example, for a three-phase 100 electric machine (N=3), the electrical phase shift angle is 360 / N = 120° and the equivalent electrical phase shift angle is kx 120° with k, an integer.

[0070] Here we have six single-phase quarters Ql, Q2, Q3, Q4, Q5, Q6 offset by a geometric angle of 60°. The number of quarters can be different. It is a multiple of the number of phases, for example three, nine or twelve. If there are support teeth 3 and phase shift teeth 5 on each side of the stator 1, we can have twelve phase shift teeth 5. If each single-phase quarter Ql, Q2, Q3, Q4, Q5, Q6 comprises three support teeth 3 on each side of the stator 1, we can have thirty-six support teeth 3 in total, twenty-four of which are provided with coils 4.

[0071] The coils 4 can be connected in star, that is to say that each phase A, B, C comprises a group of coils which comprises all the coils A1, A2 adjacent in series of a single-phase district Q1 of the same face, in series of the coils A3, A4 adjacent in series of the diametrically opposite single-phase district Q4, the assembly being in parallel with the assembly of coils A5, A6, A7, A8 of the single-phase districts Ql, Q4 of the opposite face, the groups of each phase A, B, C being connected in parallel ([Fig.5]).

[0072] Conventionally, in operation of an electric motor, when the phases of the stator 1 are supplied by an alternating electric current, an axial flux electromagnetic field is generated, axially passing through the electric machine 100 from one rotor 200 to the other 300 in the case of an electric machine with two rotors 200, 300, passing through the support teeth 3 carrying the coils 4. Each axial flux loop passes through two superimposed support teeth 3, loops back into the rotor 200, 300 at the end and passes through two adjacent support teeth 3, looping back into the opposite rotor 200, 300 to close the loop. This axial flux acting on the permanent magnets 201, 301 of the rotors 200, 300, makes it possible to drive the latter in rotation, to drive in axial rotation a shaft (not shown) integral in rotation with the rotors 200, 300.

[0073] The support and phase shift teeth 3, 5 are made of electrically insulating material, for example each made by stacking sheets or by sintering SMC (Soft Magnetic Composites) materials. Soft magnetic composite (SMC) materials are made from bonded iron powders. The iron powder is covered with an insulating layer and pressed into a solid material using a die before a final heat treatment to harden the bond.

[0074] The support teeth 3 are for example all the same.

[0075] They each have, for example, radial sections that are inscribed in an isosceles triangular shape. A head 8 of each support tooth 3 cooperates, for example, by a tenon-mortise assembly with a respective complementary assembly shape 9 formed in the first radial openings 6 of the stator yoke 2. The head 8 of the support teeth 3 is, for example, less wide or of the same width (at most) as the tooth body so that the coils 4 can be inserted axially onto a respective support tooth 3 of the first and second series, if applicable, passing through the head 8 of the support tooth 3.

[0076] For example, the two opposite sides of the same length of the head 8 cooperate with complementary assembly shapes 9 made in the opposite sides of each of the first radial openings 6 of isosceles triangular shape of the stator yoke 2 ([Fig.6]).

[0077] According to an exemplary embodiment, the heads 8 of the support teeth 3 have a mortise cooperating with a tenon of the stator yoke 2. More precisely, the head 8 of the support teeth 3 may have two rectilinear grooves extending on a respective side of the head 8, the complementary assembly form 9 being produced by two complementary rectilinear ribs extending radially in the first radial openings 6 of the stator yoke 2 ([Fig. 11]).

[0078] According to other examples of tenon-mortise assembly not shown between the support teeth 3 and the stator yoke 2, the tenon has for example a dovetail or fir tree foot male and the mortise has a complementary shape.

[0079] The end of the support teeth 3 called isthmus (also called "tooth root"), intended to face a rotor 200, 300, opposite the head 8, may have a fin 13, with a flat surface, extending beyond the tooth body carrying the coil 4 (figures 7 and 8). The fins 13 form with the tooth body, for example, a T-shaped or chamfered T-shaped cross-section. Other shapes are of course conceivable. They make it possible to protect the coils 4 interposed between the fins 13 and the head 8, under the bar of the T ([Fig.8]).

[0080] The phase shift teeth 5 are for example all the same. The number of phase shift teeth 5 is less than or equal to the number of support teeth 3.

[0081] The phase shift teeth 5 each have, for example, radial sections that are inscribed in an isosceles triangular shape. A head 11 of each phase shift tooth 5 cooperates, for example, by a tenon-mortise assembly with a respective complementary assembly shape 12 formed in the second radial openings 7 of the stator yoke 2.

[0082] For example, the two opposite sides of the same length of the head 11 cooperate with complementary assembly shapes 12 made in the opposite sides of each of the second radial openings 7 whose shape fits into an isosceles triangle of the stator yoke 2 ([Fig.6]). The phase shift teeth 5 are for example wider than the support teeth 3 and consequently, the second radial openings 7 of the stator yoke 2 are wider than the first radial openings 6.

[0083] According to an exemplary embodiment, the phase shift teeth 5 are formed from two adjacent symmetrical parts 5a, 5b ([Fig.9]).

[0084] According to an exemplary embodiment, in the case of an electrical machine 100 comprising a stator 1 interposed axially between two rotors 200, 300, it may be provided that the axially symmetrical parts 5a or 5b of the superimposed teeth 5 are secured to each other two by two (not shown), for example by gluing or are made in one piece ([Fig.2]) as will be seen later. The heads 11 of the axially symmetrical parts of the phase shift teeth 5 may then have two rectilinear and parallel tenons extending on a respective side of the teeth 5. The complementary assembly form 12 may be made by the sides of the second radial openings 7, sandwiched by the mortise of the tenons of the phase shift teeth 5 ([Fig.l 1]). Another example will be given later for the case where the machine electric 100 has only one rotor 200.

[0085] According to other examples of tenon-mortise assembly not shown between the phase shift teeth 5 and the stator yoke 2, the tenon has for example a dovetail or fir tree foot male and the mortise has a complementary shape.

[0086] The end of the phase shift teeth 5 called isthmus (also called "tooth root"), intended to face a rotor 200, 300, opposite the head 11, may have a fin 16, with a flat surface, extending beyond the tooth body. The fins 16 form with the tooth body, a cross section for example in the shape of a T or in the shape of a chamfered T. Other shapes are of course conceivable. These fins 16 make it possible, like the fins 13 of the support teeth 3, to protect the coils 4, the bar of the T of the phase shift teeth 5 partially covering the coils 4 mounted on the adjacent support tooth 3 ([Fig.4]).

[0087] This assembly of the support teeth 3 and phase shift teeth 5 to the stator yoke 2, associated with a single-phase quarter winding, makes it possible to increase the filling coefficient, for example to achieve filling coefficients of the order of 50%, which allows control of the extraction of the calories generated while guaranteeing optimal electrical insulation.

[0088] In addition, the filling coefficient can be maximized while retaining the fins 13, 16 of the isthmuses of the teeth 3, 5. This makes it possible in particular to minimize Joule losses, by maximizing the copper section and by protecting the coils from leakage fluxes at the air gap. In addition, the shape and dimensions of the isthmuses can be defined by design without any particular assembly constraints so that the quality of the mechanical torque delivered by the electrical machine 100 can be improved.

[0089] With this configuration where the winding is concentrated on support teeth 3 distributed in single-phase quarters, the compactness of the electrical machine 100 is increased and its industrial manufacturing repeatability on a large scale is guaranteed, while controlling the performance under load. Furthermore, the number of welds is reduced. In addition, this architecture makes it possible to improve the cooling of the electrical machine 100, by making it possible to integrate cooling, in particular through cooling, as described below, which makes it possible to achieve high linear loads. Finally, adaptation to higher voltage levels is also facilitated by this distribution of the winding.

[0090] According to an exemplary embodiment, the stator 1 comprises a cooling device 20 comprising at least a first and / or a second internal circuit 21, 22 surrounding the internal radial periphery of the stator yoke 2 (figures 2 and 12).

[0091] The first and second internal circuits 21, 22 comprise a respective tubular ring, coaxial with the stator yoke 2, axially facing the coil leads 4 located on the side closest to the axis. The tubular ring is radially interposed on a disc of the stator yoke 2 between the ends of the support teeth 3 and the central cylinder 14 of the stator yoke 2, for example as close as possible to the support teeth 3. It can be held by means of radial protuberances of the stator yoke 2.

[0092] The first internal circuit 21 is interposed axially between the first face of the stator yoke 2 and the coil ends of the coils 4 of the first series. The second internal circuit 22 is interposed axially between the second face of the stator yoke 2 opposite the first face, and the coil ends of the coils 4 of the second series.

[0093] The first and second internal circuits 21, 22 also have at least one fluid supply 24, respective or common to the two internal circuits 21, 22, connected to the tubular ring, passing through the head 11 of a phase shift tooth 5 (FIGS. 4 and 12). The fluid supplies 24 of the first and second internal circuits 21, 22, if applicable, may be superimposed and pass through the head 11 of the phase shift tooth 5 at the same passage. According to another example, there is a fluid supply 24 common to the first and second internal circuits 21, 22, the fluid supply 24 passing radially through the phase shift tooth 5 and axially through the stator yoke 2 to put the first and second internal circuits 21, 22 into communication.

[0094] One or all of the phase shift teeth 5 may be through teeth to allow all fluid feeds 24 to pass from the internal circuits 21, 22 of the cooling device 20.

[0095] According to a first exemplary embodiment, the first and / or second internal circuit 21, 22 has at least one fluid outlet (not shown) respective or common to the two internal circuits 21, 22, connected to the tubular ring, passing through the head 11 of a phase shift tooth 5. The fluid outlets of the first and second internal circuits 21, 22, if applicable, may be superimposed and pass through the head 11 of the phase shift tooth 11 at the same passage. According to another example, there is a fluid outlet common to the first and second internal circuits 21, 22, the fluid outlet passing axially through the phase shift tooth 5 and axially through the stator yoke 2 to put the first and second internal circuits 21, 22 into communication.

[0096] In this embodiment, the fluid enters through the at least one fluid inlet 24 and exits through the at least one fluid outlet. The fluid circulates in a closed circuit in the first and / or second circuit 21, 22 which cools the coil ends of the coils 4 by conduction of the walls of the circuits 21, 22. The fluid is, for example, water.

[0097] According to a second exemplary embodiment, the tubular ring of the first and second internal circuits 21, 22 respectively comprises at least one ejection hole 23, for example a plurality of ejection holes 23 regularly distributed on the periphery of the tubular ring, here twelve per ring, arranged on the side of the ring tubular facing the coil buns 4 ([Fig. 12]).

[0098] In this exemplary embodiment, the fluid enters through the at least one fluid inlet 24 and exits through the at least one ejection hole 23. The fluid circulates in an open circuit, it is ejected from the first and / or second circuit 21, 22 to cool the coil leads 4. The fluid can be any electrically insulating and heat-transferring liquid, making it possible to cool a component, such as oil.

[0099] According to an exemplary embodiment, a cavity 25 open on the side of the head 11 is delimited by two adjacent symmetrical parts 5a, 5b of the phase shift teeth 5 for the passage of the fluid supplies 24 ([Fig.9]).

[0100] Furthermore, in the case of a stator 1 interposed between two rotors 200, 300, the heads 11 of the two phase-shifting teeth 5 of the first and second series, each in two adjacent parts 5a, 5b, may be axially in contact or axially in one piece, to put the cavities 25 of the two phase-shifting teeth 5 in communication.

[0101] Alternatively or in addition, the cooling device 20 comprises an external circuit 26 surrounding the external radial periphery of the stator yoke 2 while being held by ends of the stator yoke 2 (Figures 2 and 12). In this case, the stator yoke 2 is preferably non-magnetic and massive.

[0102] The external circuit 26 comprises a tubular ring, coaxial with the stator yoke 2, axially facing the coil ends 4 located on the side furthest from the axis. The tubular ring is for example inserted into a peripheral end groove 27 formed in the ends of the branches 10 of the stator yoke 2 ([Fig.l 1]). This peripheral groove 27 can be formed by the radial extension of the complementary assembly shapes 9 of the stator yoke 2 (tenons for example) extending beyond the teeth 3, 5.

[0103] The external circuit 26 also has at least one fluid supply 24 connected to the tubular ring, which can be superimposed on the fluid supplies 24 of the first and second internal circuits 21, 22 (figures 4 and 12).

[0104] According to a first exemplary embodiment, the external circuit 26 has at least one fluid outlet (not shown) connected to the tubular ring. In this exemplary embodiment, the fluid enters through the at least one fluid inlet 24 and exits through the at least one fluid outlet. The fluid circulates in a closed circuit in the external circuit 26 which cools the coil ends 4 by conduction of the walls of the circuits 21, 22. The fluid is for example water.

[0105] According to a second exemplary embodiment, the tubular ring of the external circuit 26 comprises at least one ejection hole 23, for example a plurality of ejection holes 23 regularly distributed on the periphery of the tubular ring, here twelve ejection holes 23, arranged on each side of the tubular ring facing the buns. reels 4 of the first and second series where applicable.

[0106] In this exemplary embodiment, the fluid enters through the at least one fluid inlet 24 and exits through the at least one ejection hole 23. The fluid circulates in an open circuit; it is ejected from the external circuit 26 to cool the coil leads 4. The fluid can be any electrically insulating and heat-transferring liquid, making it possible to cool a component, such as oil.

[0107] It may further be provided that the casing 17 of the electrical machine 100 receiving the stator 1 and the rotors 200, 300, has at least one outlet orifice, for example formed in a side wall of the casing 17 at the height of the stator yoke 2, to allow the oil of the internal or external circuits 21, 22, 26 to exit the casing 17 of the electrical machine 100 for example by gravity.

[0108] It is also possible to provide that the stator 1 comprises at least one annular guide rim extending radially at one end of the central cylinder 14 of the stator yoke 2, to guide the return of ejected oil around the central cylinder 14 towards the outlet orifice. The annular guide rims may be formed in a respective ring 18 of the stator 1. There are for example two rings 18 fixed respectively on either side of the central cylinder 14 of the stator yoke 2 when the stator 1 has a first and a second series of teeth 3, 5 ([Fig.2]).

[0109] The internal and / or external circuits 21, 22, 26 of the cooling device 20 make it possible to cool the coils of the coils 4 as close as possible to the coils 4, where the hot points of the electrical machine 100 are located. Furthermore, in the case of open circuits, a cooling device 20 extending on the internal and external periphery of the stator 1 makes it possible to cool the coils 4 with jets of oil whose distribution is more uniform.

[0110] We will now describe an example of a method for assembling a polyphase rotating electrical machine 100 with axial electromagnetic flux.

[0111] To assemble the electrical machine 100, the stator 1 is first assembled. To do this, the coils 4 are inserted axially onto a respective support tooth 3 of the first and second series, if applicable, by passing the coils 4 through the head 8 of the support teeth 3.

[0112] Then, the support teeth 3, provided or not with coils, are assembled in the first radial openings 6 of the stator yoke 2 and the phase shift teeth 5 in the second radial openings 7, for example by radial insertion. The residual spaces between the coils 4 and the stator yoke 2 can be filled with varnish.

[0113] When the stator 1 comprises a cooling device 20 comprising a first and / or second internal circuit 21, 22, the first and / or second internal circuit 21, 22 is mounted around the central cylinder 14 before assembling the teeth of support 3 and phase shift 5 and at least one fluid supply 24 of the internal circuits 21, 22 is passed through at least one phase shift tooth 5.

[0114] When the stator 1 comprises a cooling device 20 comprising an external circuit 26, the external circuit 26 is mounted on the ends of the stator yoke 2 once all the support teeth 3 and phase shift teeth 5 have been assembled to the stator yoke 2.

[0115] Then, the coils 4 are interconnected and the stator 1 and here the two rotors 200, 300 are mounted on either side of the stator 1, in the housing 17 of the electrical machine 100.

[0116] It is understood from the above that this assembly procedure is suitable for large-scale production. Indeed, the support teeth 3 can be easily wound by axial insertion, passing through the head 8.

[0117] [Fig. 13] shows a second example of the embodiment of the stator 1.

[0118] This example differs from the previous one in that here, the support teeth 3 of the first and second series which are axially superimposed on each other two by two, are made in a single piece. The support teeth 3 are then attached to each other by their respective heads 8.

[0119] Furthermore, in this example, the phase shift teeth 5 of the first and second series which are axially superimposed on each other two by two are also made in a single piece. The phase shift teeth 5 are then attached to each other by their respective heads 11.

[0120] The isthmuses of the support teeth 3 and the phase shift tooth 5 do not have fins so as to allow the axial insertion of the coils 4 on the support teeth 3 passing through the isthmuses of the teeth 3, 5.

[0121] The other elements of this embodiment are similar to those of the first embodiment described.

[0122] Figures 14 and 15 show a third example of embodiment of the stator 1 of the electrical machine 100 in the case where the latter comprises a cooling device having a first and / or second internal circuit 21, 22 and / or an external circuit 26, in open circuit.

[0123] In this example, channels 29 are made in the stator yoke 2, for example made in two parts 2a, 2b assembling axially. More precisely, for example, an oil return channel 29 is provided in at least one branch 10 of the stator yoke 2 separating two first radial openings 6. Each channel 29 extends radially in a respective branch 10 to open at its end. The channels 29 provided in the branches 10 can communicate with a common cylindrical conduit 31 provided in the central cylinder 14 of the stator yoke 2 and closed at the axial ends, for example by means of a respective ring 18.

[0124] This oil recovery circuit internal to the stator head 2 formed by the oil return channels 29 and the cylindrical conduit 31, allow better circulation of oil, in particular to evacuate the oil which can flow next to the coils 4 in the peripheral end groove 27. This oil can then flow by gravity through another channel opening from the stator yoke 2 of another branch 30.

[0125] The other elements of this embodiment are similar to those of the first embodiments described.

[0126] Figures 16 and 17 show a fourth example of an embodiment of an electric machine 100.

[0127] This electrical machine 100 is distinguished from the previous ones by the fact that it comprises only a single rotor 200, the stator 1 comprising only a single first series of support teeth 3 and a single first series of phase shift teeth 5 assembled on a first face of the stator yoke 2 opposite the coils or permanent magnets 201 of the rotor 200.

[0128] The stator 1 thus comprises in the illustrative example six phase shift teeth 5, eighteen support teeth 3, twelve of which are provided with coils 4.

[0129] Conventionally, in operation of an electric motor, when the phases of the stator 1 are supplied with an alternating electric current, an axial flux electromagnetic field is generated, axially passing through the electric machine 100 from a rotor 200 to the stator 1, passing through the support teeth 3 carrying the coils 4. Each axial flux loop passes through a support tooth 3 provided with a coil 4, loops back into the rotor 200 and passes through an adjacent support tooth 3 by looping back into the stator yoke 2 to close the loop. This axial flux acting on the permanent magnets 201 of the rotor 200 makes it possible to drive the latter in rotation, to drive in axial rotation a shaft (not shown) integral in rotation with the rotor 200.

[0130] According to an exemplary embodiment, the assembly of the support teeth 3 and phase shift teeth 5 to the stator yoke 2 is a mortise and tenon assembly. For example, the support teeth 3 and phase shift teeth 5 have a mortise cooperating with a tenon of the stator yoke 2. More precisely, the heads 8, 11 of the support teeth 3 and phase shift teeth 5 may have two rectilinear grooves extending on a respective side of the head 8, 11, the complementary assembly shape 9, 12 being produced by two complementary rectilinear ribs extending radially from the stator yoke 2, in the first or second radial openings 6, 7.

[0131] In this exemplary embodiment, the stator 1 comprises a cooling device 20 comprising a single first internal circuit 21 surrounding the internal radial periphery of the stator yoke 2 and an external circuit 26 surrounding the external radial periphery of the stator yoke 2.

[0132] The tubular ring of the external circuit 26 is for example glued or clipped into the ex- ends of the stator head 2.

[0133] To assemble a polyphase rotating electrical machine 100 with axial electromagnetic flux of this embodiment, the stator 1 is first assembled. To do this, the coils 4 are inserted axially onto a respective support tooth 3 of the first series by passing the coils 4 through the head 8 of the support teeth 3.

[0134] Then, the support teeth 3, provided or not with coils, are assembled in the first radial openings 6 of the stator yoke 2 and the phase shift teeth 5 in the second radial openings 7, for example by radial insertion. The residual spaces between the coils 4 and the stator yoke 2 can be filled with varnish.

[0135] When the stator 1 comprises a cooling device 20 comprising a first internal circuit 21, the first internal circuit 21 is mounted around the central cylinder 14 before assembling the support teeth 3 and phase shift teeth 5 and the at least one fluid supply 24 of the internal circuit 21 is passed through at least one phase shift tooth 5.

[0136] When the stator 1 comprises a cooling device 20 comprising an external circuit 26, the external circuit 26 is mounted on the ends of the stator yoke 2 once all the support teeth 3 and phase shift teeth 5 have been assembled to the stator yoke 2.

[0137] Then, the coils 4 are interconnected and the stator 1 and the rotor 200 are mounted in the housing 17 of the electrical machine 100.

[0138] The other elements of this embodiment are similar to those of the first embodiments described.

Claims

Claims

1. Stator (1) of a polyphase rotating electrical machine (100) with axial electromagnetic flux comprising: - a stator yoke (2), - at least a first series of support teeth (3), - a plurality of coils (4) mounted around a respective support tooth (3) of the first series, - at least a first series of phase shift teeth (5), the support and phase shift teeth (3, 5) of the first series being assembled on a first face of the stator yoke (2), the support teeth (3) being distributed in single-phase quarters (Q1, Q2, Q3, Q4, Q5, Q6), a phase shift tooth (5) being interposed between the adjacent single-phase quarters (Q1, Q2, Q3, Q4, Q5, Q6), characterized in that it comprises a cooling device (20) comprising a first and / or a second internal circuit (21, 22) surrounding an internal radial periphery of the stator yoke (2), the first and / or second internal circuit (21,22) passing through at least one head (11) of a phase shift tooth (5),

2. Stator (1) according to the preceding claim, characterized in that it comprises: - a second series of support teeth (3), - a plurality of coils (4) mounted around a respective support tooth (3) of the second series, - a second series of phase shift teeth (5), the support and phase shift teeth (3, 5) of the second series being assembled on a second face of the stator yoke (2) axially opposite the first face, the support teeth (3) being distributed in single-phase quarters (Ql, Q2, Q3, Q4, Q5, Q6), a phase shift tooth (5) being interposed between the adjacent single-phase quarters (Ql, Q2, Q3, Q4, Q5, Q6).

3. Stator (1) according to the preceding claim, characterized in that the support teeth (3) of the first and second series are axially superimposed on each other two by two, heads (8) of the support teeth (3) being in contact in first radial openings (6) of the stator yoke (2) and the phase shift teeth (5) of the first and second series are axially superimposed on each other two by two, heads (11) of the phase shift teeth (5) being in contact in second radial openings (7) of the stator yoke (2).

4. Stator (1) according to the preceding claim, characterized in that the support teeth (3) of the first and second series axially superimposed on each other two by two are made in a single piece and / or the phase shift teeth (5) of the first and second series axially superimposed on each other two by two are made in a single piece.

5. Stator (1) according to one of the preceding claims, characterized in that a head (8) of each support tooth (3) cooperates by a tenon-mortise assembly with a respective complementary assembly form (9) formed in first radial openings (6) of the stator yoke (2).

6. Stator (1) according to one of the preceding claims, characterized in that a head (11) of each phase shift tooth (5) cooperates by a tenon-mortise assembly with a respective complementary assembly form (12) formed in second radial openings (7) of the stator yoke (2).

7. Stator (1) according to one of the preceding claims, characterized in that an isthmus of each support tooth (3) and phase shift tooth (5) intended to face a rotor (200, 300), opposite the head (8, 11), has a fin (13, 16) extending beyond the tooth body, the head (8) of the support teeth (3) being less wide or of the same width as the tooth body so that the coils (4) can be inserted axially on a respective support tooth (3) by passing through the head (8).

8. Stator (1) according to one of the preceding claims, characterized in that it comprises a cooling device (20) comprising an external circuit (26) surrounding the external radial periphery of the stator yoke (2) while being held by ends of the stator yoke (2).

9. Stator (1) according to claim 8, characterized in that an oil return channel (29) is provided in at least one branch (10) of the stator yoke (2) separating two first radial openings (6), the stator yoke (2) being made in two parts (2a, 2b) which are assembled axially.

10. Polyphase rotating electrical machine (100) with axial electromagnetic flux comprising at least one rotor (200, 300), characterized in that it comprises at least one stator (1) according to one of the claims previous.

11. Method for assembling a stator (1) of a polyphase rotating electrical machine (100) with axial electromagnetic flux according to one of claims 1 to 9, in which: - the coils (4) are inserted axially on a respective support tooth (3) by passing the coils (4) through the head (8) of the support teeth (3), - then, the heads (8) of the support teeth (3) are assembled in first radial openings (6) of the stator yoke (2) and the heads (11) of the phase shift teeth (5) in second radial openings (7).

12. Method for assembling a stator (1) according to the preceding claim, in which: - a first and / or a second internal circuit (21, 22) is mounted around a central cylinder (14) of the stator yoke (2) before assembling the support (3) and phase shift (5) teeth and at least one fluid supply (24) of the first and / or second internal circuit (21, 22) is passed through at least one phase shift tooth (5), and - an external circuit (26) is mounted on the ends of the stator yoke (2) once all the support (3) and phase shift (5) teeth have been assembled to the stator yoke (2).

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