Cooling device for windings, stators, electrical machines and associated aircraft

Abstract

The cooling device (8) for the winding (9a, 9b) comprises a support (11) having a first face (11a), a second face (11b) opposite the first face, and a first hydraulic connection (12) connected to a first end of the support. The support has a central opening (11c) leading to the first and second faces. Each face of the support is configured to contact a winding (9a, 9b) wound around the central opening of the support. The hydraulic connection is configured to be supplied with a cooling fluid. The cooling device is made of an electrically insulating ceramic. (See Figure 3 for abbreviations.)

Description

Title of the invention: Cooling device for windings, stators, electrical machines and associated aircraft technical field

[0001] The invention relates to the cooling of windings of an electrical machine.

[0002] The invention relates more particularly to a winding cooling device and an electrical machine comprising such a device. Previous techniques

[0003] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies to both new types of aircraft and those already in service, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively working for several years now to contribute to the fight against climate change.

[0004] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the factors impacting all phases of design and development in order to obtain aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental consequences, with the aim of improving the energy efficiency of aircraft.

[0005] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0006] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as essential complements to technological progress, aviation biofuels.

[0007] Electric or hybrid aircraft propulsion systems require the use of electric machines capable of competing with, or even exceeding, the performance of internal combustion engines.

[0008] Electrical machines intended for the propulsion of electric aircraft must deliver significant specific power.

[0009] In this context, the use of electrical machines made from superconducting materials makes it possible to obtain good efficiency and significant specific powers.

[0010] Indeed, when superconducting materials are cooled to a temperature below their critical temperature, typically below 100 Kelvin or even 150 Kelvin, superconducting materials exhibit zero resistivity, thus offering the possibility of passing currents without losses.

[0011] It is also known to produce electrical machines from "hyperconducting" materials, referring to conventional conductive materials brought to very low temperatures to increase their electrical conductivity and allowing the production of electrical machines with good efficiency and high specific power.

[0012] In order to maintain coils made of superconducting or hyperconducting material at a cryogenic temperature generally below 77 Kelvin, below the critical temperature of said materials, it is necessary to have a high-performance cryogenic cooling system that removes the heat losses generated by the coils.

[0013] It is already known to deposit coils powered by a direct current DC, in particular rotor coils, on or between plates generally made of copper connected to a cooling terminal located at one or more of the coil heads.

[0014] Since copper has excellent thermal conductivity, heat losses are extracted by conduction.

[0015] If we consider stator coils, they are inserted with the copper plates into notches of a ferromagnetic body of the stator.

[0016] However, when the stator coils are powered by alternating current AC, eddy currents are generated in the copper plates by the magnetic field generated by the coils, said currents generating significant thermal losses.

[0017] In addition, as the stator coils and copper plates are inserted into the slots, sufficient space must be provided between the stator coils and the ferromagnetic body to ensure thermal decoupling between said coils and said body.

[0018] It is known to arrange the stator coils powered by a DC current in cooling channels to have direct contact between the conductors and the cryogenic cooling fluid.

[0019] Since the cryogenic coolant circulating in the channels is generally a gas at a temperature between 22 Kelvin and 65 Kelvin injected under high pressure between 15 and 20 bars, the channels are made of metallic materials to withstand the pressure at the temperature of the cryogenic coolant while ensuring thin wall thicknesses to be able to fit within the notches of the ferromagnetic body of the stator.

[0020] However, when the stator coils are powered by an alternating current AC, eddy currents are generated in the metallic channels by the magnetic field generated by the coils, said currents generating significant thermal losses. Description of the invention

[0021] The object of the invention is to overcome all or part of these drawbacks.

[0022] To this end, the invention is the result of technological research aimed at significantly improving aircraft performance and, in this sense, contributes to reducing the environmental impact of aircraft. For this purpose, the invention relates to a winding cooling device.

[0023] The cooling device comprises a support having a first face, a second face opposite the first face and a first hydraulic connection connected to a first end of the support, the support having a central opening leading to the first face and the second face, each face of the support being configured to come into contact with a winding wound around the central opening of the support, the hydraulic connection being configured to be supplied by a cooling fluid.

[0024] The cooling device is made of an electrically insulating ceramic (or one with low electrical conductivity).

[0025] Thus, an alternating current AC supplying the windings does not generate eddy currents in the cooling device.

[0026] Preferably, the cooling device includes a second hydraulic connection linked to a second end of the support opposite to the first end.

[0027] Advantageously, the support is a ceramic plate.

[0028] Preferably, the cooling device further comprises two ceramic support elements, each support element protruding from one face of the support and being on the periphery of the opening so that the winding in contact with one face of the support is wound around the support element protruding from said face and in contact with said element.

[0029] Advantageously, the walls of the support element form a cooling duct ceramic unit, each hydraulic connection being linked to the cooling duct.

[0030] Preferably, the cooling device further comprises two ceramic cooling channels, each cooling channel protruding from one face of the support and being on the periphery of the opening so that the winding in contact with one face of the support is wound around the cooling channel protruding from said face and in contact with said channel, the open face of the channel being connected to the cooling conduit.

[0031] A stator for an electric machine is also proposed.

[0032] The stator comprises at least one stator tooth, a first winding, a second winding and a first cooling device as defined previously.

[0033] Each winding has a first face and a second face opposite the first face, the stator tooth being inserted into the central opening of the first cooling device, the first winding being wound around the tooth and the first face of the first winding resting on the first face of the support of the first cooling device, and the second winding being wound around the tooth and the first face of the second winding resting on the second face of the support of the first cooling device.

[0034] Preferably, the stator further comprises a second cooling device as defined above and a third cooling device as defined above, the stator tooth being inserted in the central opening of the second and third cooling devices, the second face of the first winding resting on the first face of the support of the second cooling device and the second face of the second winding resting on the first face of the support of the third cooling device.

[0035] Advantageously, the stator comprises at least one stator tooth, a first winding, a second winding, a first cooling device as defined previously, and a second cooling device as defined previously, each winding having a first face and a second face opposite to the first face, the stator tooth being inserted into the central opening of the first cooling device and into the central opening of the second cooling device, the first winding being wound around the tooth and the first face of the first winding resting on the first face of the support of the first cooling device, the second winding being wound around the tooth and the first face of the second winding resting on the first face of the second cooling device, and the second face of the first winding and the second face of the second winding resting on each other.

[0036] Preferably, the first and second windings are identical, each side of the support for each cooling device conforming to the faces of the windings.

[0037] An aircraft comprising a stator as defined above is also proposed.

[0038] An electric machine is also proposed.

[0039] The electrical machine comprises a first winding, a second winding and a first cooling device as defined previously.

[0040] Each winding has a first face and a second face opposite the first face, the first winding being wound around the central opening of the support and the first face of the first winding resting on the first face of the support of the first cooling device, and the second winding being wound around the central opening of the support and the first face of the second winding resting on the second face of the support of the first cooling device.

[0041] Preferably, the electric machine further comprises a second cooling device as defined above and a third cooling device as defined above, the first winding being wound around the central opening of the support of the second cooling device and the second face of the first winding resting on the first face of the support of the second cooling device, the second winding being wound around the central opening of the support of the third cooling device and the second face of the second winding resting on the first face of the support of the third cooling device.

[0042] Advantageously, the electrical machine comprises a first winding, a second winding, a first cooling device as defined previously, and a second cooling device as defined previously.

[0043] Each winding has a first face and a second face opposite the first face, the first winding being wound around the central opening of the support of the first cooling device and the first face of the first winding resting on the first face of the support of the first cooling device, the second winding being wound around the central opening of the support of the second cooling device and the first face of the second winding resting on the first face of the second cooling device, and the second face of the first winding and the second face of the second winding resting on each other.

[0044] Preferably, the first and second windings are identical, each face of the support of each cooling device conforming to the faces of the windings.

[0045] An aircraft comprising an electrical machine as defined above is also proposed. Brief description of the drawings

[0046] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0047] - Figure [Fig. 1] schematically illustrates an example of an aircraft according to the invention;

[0048] - Figure [Fig.2] schematically illustrates an example of an embodiment of a stator according to the invention;

[0049] - Figure [Fig.3] schematically illustrates a first example of the realization of a magnetic pole comprising a first example of the realization of a cooling device according to the invention;

[0050] - Figure [Fig.4] schematically illustrates a second example of the embodiment of cooling device according to the invention;

[0051] - Figures [Fig.5] and [Fig.6] schematically illustrate a third example of implementation of the cooling device according to the invention;

[0052] - Figure [Fig.7] schematically illustrates a fourth example of the realization of a cooling device according to the invention;

[0053] - Figure [Fig.8] schematically illustrates a fifth example of an embodiment of cooling device according to the invention;

[0054] - Figure [Fig.9] schematically illustrates a second example of the realization of a magnetic pole according to the invention; and

[0055] - Figure [Fig. 10] schematically illustrates a third example of the realization of a magnetic pole according to the invention. Detailed description

[0056] Reference is made to [Fig.1] which schematically illustrates an example of an aircraft 1 comprising cryogenic electrical machines 2.

[0057] Each electric machine 2 is for example connected to a propeller 3 of the aircraft 1.

[0058] As illustrated in [Fig.1], aircraft 1 may be an airplane.

[0059] Alternatively, aircraft 1 may be a helicopter.

[0060] Figure 2 schematically illustrates an example of an embodiment of a stator 4 of the electric machine 2.

[0061] The stator 4 includes a segmented magnetic circuit 5 comprising stator segments 6 arranged next to each other to form the magnetic circuit 5 and held in a stator yoke (not shown).

[0062] Each segment 6 is made from an assembly of laminated magnetic sheets.

[0063] Each segment 6 comprises a stator tooth 7.

[0064] According to another embodiment, the magnetic circuit 5 is made in one piece from an assembly of laminated magnetic sheets, each magnetic sheet forming a radial section of the stator.

[0065] The stator 4 further comprises as many cooling devices 8 as teeth 7 and windings 9a, 9b.

[0066] As shown, an assembly comprising a first winding 9a and a second winding 9b separated by a device 8 and arranged around a stator tooth 7 forms a magnetic pole 10.

[0067] The windings 9a, 9b are powered by an alternating current AC.

[0068] The electrical connections of the windings 9 are not shown.

[0069] Fig. 3 schematically illustrates a first example of the realization of the magnetic pole 10 as represented in Fig. 2, including a first example of the device 8.

[0070] The device 8 includes a support 11 having a first face 1la and a second face 11b opposite the first face 1la, and a first hydraulic connection 12 connected to a first end of the support 11.

[0071] The first hydraulic connection 12 includes two openings 12a, 12b so that a cooling fluid passes through the first hydraulic connection 12.

[0072] The first hydraulic connection 12 can be located at the heads of the windings 9a, 9b.

[0073] The first hydraulic connections 12 of the devices 8 of the stator 4 are connected together in series for example by pipes (not shown) forming a cooling fluid supply loop.

[0074] The ends of the supply loop are connected to a cooling fluid supply device (not shown) capable of injecting cooling fluid at one end of the loop and cooling the cooling fluid discharged from the second end of the loop.

[0075] The cooling fluid can in particular be chosen from liquid nitrogen, gaseous helium and liquid or gaseous hydrogen, and is maintained at a cryogenic temperature, for example below 22 Kelvin when the cooling fluid is liquid hydrogen.

[0076] The support 11 has a central opening 1 leading to the first face 1a and the second face 11b.

[0077] The central opening 1 accommodates the tooth 7.

[0078] Each winding 9a, 9b is wound around the central opening 1 and comprises a first face 9a1, 9b1 and a second face 9a2, 9b2 opposite to the first face 9a1, 9b1.

[0079] The first face 9al, 9b 1 and second face 9a2, 9b2 are perpendicular with respect to the insertion direction of the winding mandarin of said winding.

[0080] The first face 9a 1 of the first winding 9a rests on the first face 1 la of the support 11 and the first face 9b 1 of the second winding 9b rests on the second face 11b of the support IL

[0081] The windings 9a, 9b can be made of a superconducting material, for example according to one of the following materials: MgB2, REBaCuO, BiSrCaCuO suitable for aeronautical applications.

[0082] Alternatively, the windings 9a, 9b can be made of a conventional electrically conductive material such as copper.

[0083] The cooling device is made of a ceramic so that the support 11 and the hydraulic connection 12 are made of a ceramic material, in particular of a ceramic material having low electrical conductivity and high thermal conductivity at cryogenic temperature, for example of aluminium monoxide Al₂O, magnesium monoxide MgO, silicon carbide SiC, silicon monoxide SiO.

[0084] The support 11 is a ceramic plate.

[0085] The heat losses generated by the AC-powered windings 9a, 9b are removed by thermal conduction via the support 11 into the cooling fluid circulating in the first hydraulic connection 12 so that the windings 9a, 9b are maintained at the cryogenic temperature allowing the operation of the superconducting windings 9a, 9b by removing the heat losses generated by the windings 9a, 9b.

[0086] Since the ceramic material used is electrically insulating, said material exhibits very low electrical conductivity. The AC current supplying the windings 9a, 9b does not generate eddy currents in the device 8.

[0087] The cooling device 8 is for example produced by additive manufacturing, sintering, flash sintering (“Spark Plasma Sintering” in English).

[0088] The support 11 is for example made so that each of its faces 1a, 11b fits the faces of the identical windings 9a, 9b as shown.

[0089] Figure 4 schematically illustrates a second example of the embodiment of device 8.

[0090] The support 11 and the first connection 12 located at the first end of the support 11 are found as described previously in [Fig.3].

[0091] The device 8 further includes a second hydraulic connection 13 located at the second end of the support 11 opposite the first end of the support 11.

[0092] The second hydraulic connection 13 includes two openings 13a, 13b so that the cooling fluid passes through the second hydraulic connection 13.

[0093] The second hydraulic connections 13 of the devices 8 of the stator 4 are connected together in series for example by pipes (not shown) forming a second cooling fluid supply loop.

[0094] The ends of the second supply loop are connected to the cooling fluid supply device.

[0095] The heat losses generated by the windings 9a, 9b are removed by thermal conduction via the support 11 into the cooling fluid circulating in the first hydraulic connection 12 and in the second hydraulic connection 13 further improving the cooling of the windings 9a, 9b.

[0096] The first and second hydraulic connections 12, 13 are, for example, ceramic tubes glued or welded to the support 11.

[0097] Figures 5 and 6 schematically illustrate a third example of an embodiment of the cooling device 8.

[0098] Fig. 5 illustrates the third embodiment of the cooling device 8 on which the windings 9a, 9b are arranged and Fig. 6 illustrates the third embodiment of the cooling device 8 without the windings 9a, 9b.

[0099] The support 11 and the first connection 12 located at the first end of the support 11 are found as described previously in [Fig.3].

[0100] The cooling device 8 further includes two ceramic support elements 14, each support element 14 protruding from a face lia, 11b of the support 11 (see [Fig.6]).

[0101] Each support element 14 is arranged around the perimeter of the central opening 1 so that the first stator winding 9a in contact with the first face 1a of the support 11 is wound around the support element 14 protruding from said face 1a and in contact with said element 14, and so that the second stator winding 9b in contact with the second face 11b of the support 11 is wound around the support element 14 protruding from said face 11b and in contact with said element 14.

[0102] The height of the support element 14 in a direction parallel to the insertion direction of the winding mandarin can be equal to the thickness of the winding 9a, 9b defined between the first and second faces of the winding.

[0103] The support element 14 allows the heat exchange surface by conduction to be increased between the support 11 and the windings 9a, 9b in order to improve the cooling of the windings 9a, 9b.

[0104] Of course, the third example of the cooling device 8 can also include the second hydraulic connection 13 shown in [Fig.4], the second hydraulic connection 13 being located at the second end of the support 11.

[0105] In the examples of embodiment of the cooling device 8 presented above Previously, the heat losses generated by the windings 9a, 9b are evacuated by conduction through the ceramic support 11 into the cooling fluid circulating in the hydraulic connection(s) linked to said support 11.

[0106] In order to further improve the dissipation of heat losses generated by the windings 9a, 9b, [Fig.7] schematically illustrates a partial view of a fourth embodiment of the cooling device 8 in which the cooling fluid circulates inside the support of the device.

[0107] The cooling device 8 includes a ceramic support 15 having a first face 15a, a second face 15b opposite the first face 15a, and a central opening 15c leading to the first face 15a and the second face 15b.

[0108] The windings 9a, 9b are wound around the central opening 15c.

[0109] The central opening 15 accommodates the tooth 7.

[0110] The support 15 further includes the first hydraulic connection 12 (not shown in [Fig.7]) connected to a first end of the support 15.

[0111] The first hydraulic connection was removed in order to represent a section of support 15.

[0112] The inside of the support 15 is hollow to form a cooling channel 15d.

[0113] The cooling duct is formed by the walls of the support 15 so that the cooling fluid is in contact with the first and second faces 15a, 15b.

[0114] The first face 9al of the first winding 9a rests on the first face 15a of the support 15 and the first face 9b 1 of the second winding 9b rests on the second face 15b of the support 15.

[0115] The cooling duct 15d is connected to the first hydraulic connection 12 so that the cooling fluid circulates in the cooling duct 15d.

[0116] As the windings 9a and 9b rest on the faces 15a, 15b of the support 15 and the cooling fluid circulating in the cooling duct is in contact with the faces 15a, 15b of the support 15, the exchange surface between the first face of each winding 9a, 9b and the cooling fluid is increased allowing better cooling of the windings 9a, 9b compared to the support 11 described previously in figures 3, 4, 5, 6.

[0117] Of course, the fourth example of device 8 can also include the second hydraulic connection 13 shown in [Fig.4], the second hydraulic connection 13 being located at the second end of the support 15 and connected to the cooling duct 15d to supply the cooling channel 15d with cooling fluid.

[0118] Figure 8 schematically illustrates a cross-section of a fifth embodiment of the cooling device 8, comprising the fourth embodiment of the device 8 shown in Figure 7 and comprising two protruding support elements 14 as in the third embodiment illustrated in figures 5 and 6, which are hollow support elements forming two ceramic cooling channels 14a, each cooling channel protruding from a face 15a, 15b of the support 15.

[0119] Each protruding cooling channel 14a is located on the periphery of the opening 15c of the support 15 so that the stator winding 9a, 9b in contact with a face 15a, 15b of the support 15 is wound around the protruding cooling channel of said face and is in contact with said channel.

[0120] The open face of the cooling channels 14a is connected to the cooling duct 15d.

[0121] The protruding cooling channels 14a increase the exchange surface between the windings 9a, 9b and the cooling fluid circulating in the protruding cooling channels 14a and the cooling duct 15d, improving the cooling of the windings 9a, 9b compared to the support 15 comprising only the cooling duct 15d.

[0122] Fig. 9 illustrates a second embodiment of the magnetic pole 10.

[0123] The magnetic pole 10 comprises the tooth 7, the stator windings 9a, 9b, the first cooling device 8 and a second cooling device 16.

[0124] The first cooling device 8 is made according to one of the embodiment examples illustrated in Figures 3, 4, 5 and 6, 7, 8 and the second cooling device 16 is made according to one of the embodiment examples illustrated in Figures 3, 4, 5 and 6, 7, 8.

[0125] The first cooling device 8 and the second cooling device 16 can be made according to the same embodiment or be made according to different embodiments.

[0126] In what follows, it is assumed that the first cooling device 8 and the second cooling device 16 are each made according to the fourth embodiment illustrated in [Fig.7], or its variants.

[0127] The central opening 15c of the support 15 of the first cooling device 8 accommodates the tooth 7.

[0128] The second cooling device 16 includes the support 17 comprising the first face 17a, the second face 17b and the central opening 17c receiving the tooth 7.

[0129] The second cooling device 16 includes the first hydraulic connection 12.

[0130] The first stator winding 9a is wound around the central opening 15c of the support 15 of the first cooling device 8 and the first face 9al of the first winding 9 rests on the first face 15a of the support 15 of the first cooling device 8.

[0131] The second stator winding 9b is wound from the central opening 17c of the support 17 of the second cooling device 16 and the first face 9bl of the second winding 9b rests on the first face 17a of the support 17 of the second cooling device 16.

[0132] The second face 9a2 of the first stator winding 9a and the second face 9b2 of the second stator winding 9b rest on each other.

[0133] The magnetic pole 10 includes two cooling devices 8, 16 allowing to improve the cooling of the stator windings 9a, 9b compared to the first example of embodiment of the magnetic pole 10 illustrated in [Fig.3].

[0134] Fig. 10 illustrates a third example of the realization of the magnetic pole 10.

[0135] The magnetic pole 10 comprises the tooth 7, the stator windings 9a, 9b, the first cooling device 8, second cooling device 16 and third cooling device 18.

[0136] The third cooling device 18 is made according to one of the embodiment examples illustrated in figures 3, 4, 5 and 6, 7, 8 or their variants.

[0137] The first cooling device 8, the second cooling device 16 and the third cooling device 18 can be made according to the same embodiment or be made according to different embodiments.

[0138] It is assumed in what follows that the first cooling device 8, the second cooling device 16 and the third cooling device 18 are each made according to the fourth embodiment illustrated in [Fig.7] or its variants.

[0139] The central opening 15c of the support 15 of the first cooling device 8 and the central opening 17c of the support 17 of the second cooling device 16 accommodate the tooth 7.

[0140] The third cooling device 18 includes the support 19 comprising the first face 19a, the second face 19b and the central opening 19c receiving the tooth 7.

[0141] The third cooling device 18 includes the first hydraulic connection 12.

[0142] The first stator winding 9a is wound around the central opening 15c of the support 15 of the first cooling device 8 and the central opening 17c of the support 17 of the second cooling device 16, and the first face 9al of the first winding 9 rests on the first face 15a of the support 15 of the first cooling device 8.

[0143] The second face 9a2 of the first stator winding 9a rests on the first face 17a of the support 17 of the second cooling device 16.

[0144] The second stator winding 9b is wound around the central opening 15c of the bracket 15 of the first cooling device 16 and the central opening 19c of the bracket 19 of the third cooling device 18, and the first face 9b 1 of the second winding 9b rests on the second face 15b of the support 15 of the first cooling device 8.

[0145] The second face 9b2 of the second stator winding 9b rests on the first face 19a of the support 19 of the third cooling device 18.

[0146] The magnetic pole 10 comprises three cooling devices 8, 16, 18 arranged so that each face 9a 1, 9a2, 9b 1, 9b2 of each winding 9a, 9b is in contact with a face 15a, 15b, 17a, 19a of a cooling device 8, 16, 18 improving the cooling of the windings 9a, 9b compared to the first and second embodiments of the magnetic pole 10 illustrated in Figures 3 and 9.

[0147] In the examples of embodiment of the cooling devices previously described, the cooling devices are integrated into the stator 4 of the electrical machine 2 to cool the windings 9a, 9b.

[0148] The examples of embodiment of the cooling devices described above can be integrated into the rotor (not shown) of the electric machine 2 to cool first and second windings integrated into the rotor of the machine 2.

[0149] The electric machine 2 may include cooling devices integrated in the stator 4 to cool the first and second windings 9a, 9b and / or in the rotor to cool the first and second windings of said rotor of said electric machine 2.

[0150] The electric machine 2 can be an electromagnetic linear actuator comprising a winding cooling device as described above.

Claims

Demands

1. Cooling device (8, 16, 18) for winding (9a, 9b), the device comprising a support (11, 15, 17, 19) having a first face (11a, 15a, 17a, 19a), a second face (11b, 15b, 17b, 19b) opposite the first face and a first hydraulic connection (12) connected to a first end of the support, the support having a central opening (11c, 15c, 17c, 19c) opening onto the first face and the second face, each face of the support being configured to come into contact with a winding (9a, 9b) wound around the central opening of the support, the first hydraulic connection being configured to be supplied by a cooling fluid, characterized in that the cooling device is made of an electrically insulating ceramic.

2. Cooling device according to claim 1, comprising a second hydraulic connection (13) connected to a second end of the support (11) opposite the first end.

3. Cooling device according to any one of claims 1 and 2, wherein the support (11) is a ceramic plate.

4. Cooling device according to claim 3, further comprising two ceramic support elements (14), each support element projecting from a face (1a, 11b) of the support (11) and being on the periphery of the opening (1a) so that the winding (9a, 9b) in contact with a face of the support is wound around the support element projecting from said face and in contact with said element.

5. Cooling device according to any one of claims 1 and 2, wherein walls of the support element (15) form a ceramic cooling duct (15d), each hydraulic connection (12) being connected to the cooling duct.

6. Cooling device according to claim 5, further comprising two ceramic cooling channels, each cooling channel projecting from one face of the support and being on the periphery of the opening such that the winding in contact with one face of the support is wound around the cooling channel projecting from said face and in contact with said channel, the open face of the channel being connected to the cooling duct.

7. Stator (4) for an electrical machine, comprising at least one stator tooth (7), a first winding (9a), a second winding (9b) and a first cooling device (8) according to any one of claims 1 to 6, each winding having a first face (9al, 9bl) and a second face (9a2, 9b2) opposite the first face, the stator tooth being inserted into the central opening (11c, 15c) of the first cooling device, the first winding (9a) being wound around the tooth and the first face (9al) of the first winding resting on the first face (lia, 15a) of the support (11, 15) of the first cooling device, and the second winding (9b) being wound around the tooth and the first face (9b1) of the second winding resting on the second face (11b, 15b) of the support of the first cooling device.

8. Stator (4) according to claim 7, further comprising a second cooling device (16) according to any one of claims 1 to 6 and a third cooling device (18) according to any one of claims 1 to 6, the stator tooth (7) being inserted into the central opening (16c, 18c) of the second and third cooling devices (16, 18), the second face (9a2) of the first winding (9a) resting on the first face (17a) of the support (17) of the second cooling device and the second face (9b2) of the second winding (9b) resting on the first face (19a) of the support (19) of the third cooling device.

9. Stator (4) for an electric machine, comprising at least one stator tooth (7), a first winding (9a), a second winding (9b), a first cooling device (8) according to any one of claims 1 to 6, and a second cooling device (16) according to any one of claims 1 to 6, each winding comprising a first face (9a1, 9b1) and a second face (9a2, 9b2) opposite the first face, the stator tooth being inserted into the central opening (15c) of the first cooling device (8) and into the central opening (17c) of the second cooling device (16), the first winding (9a) being wound around the tooth (7) and the first face (9a1) of the first winding resting on the first face (15a) of the support (15) of the first cooling device,the second winding (9b) being wound around the tooth (7) and the first face (9bl) of the second winding resting on the first face (17b) of the second cooling device (16), and the second face (9a2) of the first winding and the second face (9b2) of the second winding resting on each other.

10. Stator (4) according to any one of claims 7 to 9, wherein the first and second windings (9a, 9b) are identical, each face (11a, 11b, 15a, 11b, 19a, 19b) of the support (11, 15, 19) of each cooling device (8, 16, 18) conforming to the faces (9a1, 9a2, 9b1, 9b2) of the windings.

11. An electric machine (2), comprising a first winding (9a), a second winding (9b) and a first cooling device (8) according to any one of claims 1 to 6, each winding comprising a first face (9al, 9bl) and a second face (9a2, 9b2) opposite to the first face, the first winding (9a) being wound around the central opening of the support and the first face (9al) of the first winding resting on the first face (1a, 15a) of the support (11, 15) of the first cooling device, and the second winding (9b) being wound around the central opening of the support and the first face (9b1) of the second winding resting on the second face (11b, 15b) of the support of the first cooling device.

12. An electric machine (2) according to claim 11, further comprising a second cooling device (16) according to any one of claims 1 to 6 and a third cooling device (18) according to any one of claims 1 to 6, the first winding being wound around the central opening of the support of the second cooling device and the second face (9a2) of the first winding (9a) resting on the first face (17a) of the support (17) of the second cooling device, the second winding being wound around the central opening of the support of the third cooling device and the second face (9b2) of the second winding (9b) resting on the first face (19a) of the support (19) of the third cooling device.

13. An electrical machine (2), comprising a first winding (9a), a second winding (9b), a first cooling device (8) according to any one of claims 1 to 6, and a second cooling device (16) according to any one of claims 1 to 6, each winding comprising a first face (9a1, 9b1) and a second face (9a2, 9b2) opposite the first face, the first winding (9a) being wound around the central opening of the support of the first cooling device and the first face (9a1) of the first winding resting on the first face (15a) of the support (15) of the first cooling device, the second winding (9b) being wound around the central opening of the support of the second cooling device and the first face (9b 1) of the second winding resting on the first face (17b) of the second cooling device (16), and the second face (9a2) of the first winding and the second face (9b2) of the second winding resting on each other.

14. Electric machine (2) according to any one of claims 11 to 13, wherein the first and second windings (9a, 9b) are identical, each face (11a, 11b, 15a, 11b, 19a, 19b) of the support (11, 15, 19) of each cooling device (8, 16, 18) conforming to the faces (9a1, 9a2, 9b1, 9b2) of the windings.

15. Aircraft (1) comprising an electric machine (2) according to any one of claims 11 to 14.

Images