Propulsion unit for an aircraft

Abstract

The invention relates to a propulsion unit comprising: an electric motor (10), which includes an annular stator (11) about a longitudinal axis (X) and a rotor arranged radially inside the stator (11), so as to be rotated about the longitudinal axis (X); a power electronic module (20) suitable for supplying electricity to the electric motor (10), the power electronic module (20) comprising an annular casing (21) which extends along the longitudinal axis (X), the casing (21) of the power electronic module (20) comprising a first end disposed longitudinally opposite a first end of the stator (11) of the electric motor (10); means for cooling the electric motor (10) and the power electronic module (20), the cooling means comprising a heat sink (30) inserted longitudinally between the first end of the stator (11) of the electric motor (10) and the first end of the casing (21) of the power electronic module (20).

Description

Description Title: Aircraft Propellant Technical field

[0001] The present description relates to an aircraft propellant. In particular, the present description relates to an aircraft propellant with electric or hybrid propulsion. Prior art

[0002] Carbon emission limitation objectives in the aeronautics industry are pushing manufacturers to turn to electric or hybrid propulsion systems (i.e. including both a thermal and an electric propulsion system).

[0003] In a known manner, an electric thruster as shown in FIG. 1 comprises an electric motor 10 and a power electronics module 20. In order to make the electric thruster compact and to limit the length of wiring, the power electronics module 20 is directly connected to the electric motor 10.

[0004] The electric motor 10 is generally a permanent magnet synchronous motor. For this purpose, the electric motor 10 comprises an annular stator 10 and a rotor arranged inside the stator 10. The rotor comprises a shaft 12 which extends along a longitudinal axis X.

[0005] The power electronics module 20 comprises an annular casing 21 which defines a passage in the longitudinal direction and which is crossed by the shaft 12 of the rotor. The power electronics module 20 makes it possible to convert a direct voltage into an alternating voltage, in particular three-phase, to power the electric motor 10. The direct voltage is delivered by a direct voltage source such as an electric battery. To enable the electrical conversion, the power electronics module 20 comprises a plurality of three-phase inverters mounted annularly on the casing 21 so as to be directly electrically connected to the stator 10. The power electronics module 20 may further comprise three power modules per inverter, i.e. one for each inverter output, to power the stator 10 and drive the shaft 12 of the rotor in rotation about the longitudinal axis X.

[0006] Because the electric motor 10 and the power electronics module 20 form a single unit, the power electronics module 20 is installed in an unfavorable vibration and thermal environment. To limit the risk of breakdowns and malfunctions, a redundancy solution is then provided. For this purpose, the power electronics module 20 comprises two parallel power paths which can operate individually or collectively. As a result, the power electronics module 20 comprises a high number of power modules, which generates an even higher amount of heat.

[0007] To avoid breakdowns and to maintain optimal performance, it is then necessary to cool the electric thruster and in particular the power electronics module 20. To do this, it is known to arrange a cooling circuit on or in the wall of the casing 21 of the power electronics module 20 and to supply it with a cooling fluid so as to allow cooling of the power modules.

[0008] The cooling provided by such a cooling system is, however, limited. Furthermore, increasing its performance runs counter to the objectives of reducing size and weight. Such a cooling system also has the disadvantage of being susceptible to leaks and requiring external mechanical components to ensure its operation (e.g., a pump for circulating the fluid in the duct). Summary

[0009] There is provided an aircraft propellant, the propellant comprising: - an electric motor which comprises an annular stator around a longitudinal axis and a rotor arranged, at least in part, radially inside the stator, to be driven in rotation around the longitudinal axis, - a power electronics module adapted to supply the electric motor with electricity, the power electronics module comprising an annular casing which extends along the longitudinal axis, the casing of the power electronics module comprising a first end arranged longitudinally opposite a first end of the stator of the electric motor, - means for cooling the electric motor and the power electronics module, the cooling means comprising a heat sink inserted longitudinally between the first end of the stator of the electric motor and the first end of the casing of the power electronics module.

[0010] The heat sink allows the heat generated by the electric motor and the power electronics module to be dissipated to the ambient air surrounding the motor and the power electronics module. The heat sink also allows heat to be dissipated passively. In this sense, the heat sink can be described as passive. This is because the heat generated by the motor and the power electronics module is transferred to the heat sink by thermal conduction due to the contact between the heat sink and each of the motor and the power electronics module. The heat is then removed by convection with the ambient air. In this, the heat sink differs from active heat exchangers which include a working fluid circulating in a sealed conduit and for which the heat is removed via the working fluid.

[0011] Thus, the heat sink has the advantage of not requiring an external mechanical element to ensure its operation and advantageously does not present any risk of leaks. Such a heat sink is therefore more reliable.

[0012] The heat sink may bear along the longitudinal axis on the one hand on the first end of the stator of the electric motor and on the other hand on the first end of the casing of the power electronics module. The heat sink may bear on the first end of the stator of the electric motor in a first direction of the longitudinal direction and on the first end of the casing of the power electronics module in a second direction of the longitudinal direction. The heat sink may comprise at least a first face bearing on the first end of the stator of the electric motor and at least a second face, longitudinally opposite the first face, bearing on the first end of the casing of the power electronics module.

[0013] The heat sink may include a radially outer face that is devoid of any contact with a conductive solid element, in particular the stator of the motor and / or the casing of the power electronics module. The radially outer face of the heat sink may be configured to allow heat transfer with ambient air external to the motor and the power electronics module.

[0014] The stator of the electric motor and the housing of the power electronics module may have a cross-section perpendicular to the longitudinal axis having the same shape and dimensions. The stator of the electric motor may be a cylinder of circular cross-section extending along the longitudinal axis. The housing of the power electronics module may be a cylinder of circular cross-section extending along the longitudinal axis. The circular cross-section of the stator may have the same diameter as the circular cross-section of the housing of the power electronics module.

[0015] The housing of the power electronics module and the stator of the electric motor can be joined to each other at their first end. The first ends of the stator and the housing can be considered in the longitudinal direction. The housing can be connected to the stator of the electric motor, for example by bolted connections.

[0016] The heat sink may comprise a disc which extends perpendicular to the longitudinal axis, the disc comprising at least a first face bearing on the first end of the stator of the electric motor and at least a second face, longitudinally opposite the first face, bearing on the first end of the casing of the power electronics module.

[0017] The heat sink disc, due to its circular shape, allows for uniform heat dissipation around the longitudinal axis. The disc can have the same diameter as the circular section of the motor stator and the housing of the power electronics module. The radially external face of the heat sink can be cylindrical of revolution around the longitudinal axis.

[0018] The heat sink may comprise at least one fin extending radially outward from the periphery of the disc, the heat sink preferably comprising a plurality of fins distributed regularly around the longitudinal axis, the fins of the heat sink being more preferably arranged in groups of at least two fins. Also, said at least one fin may extend radially outward from the radially outer face of the disc. The fins make it possible to increase the heat exchange surface by convection between the disc and the ambient air, thus improving the performance of the heat sink.

[0019] The heat sink may be made of a material suitable for dissipating heat. The heat sink may be made of a metallic material, such as aluminum or copper.

[0020] The rotor may include a shaft extending along the longitudinal axis, the shaft extending radially within the housing of the power electronics module, the heat sink including an opening through which the rotor shaft extends. The shaft may project from a longitudinal end of the housing of the power electronics module that is opposite the electric motor. The shaft may drive a propeller of the thruster, possibly via a gearbox.

[0021] The cooling means may comprise at least one annular row of blades secured to the rotor shaft, the annular row of blades being arranged radially inside the casing, the annular row of blades being shaped to propel a flow of air onto the heat sink when it is rotated about the longitudinal axis via the shaft.

[0022] The ventilated airflow over the heat sink improves the evacuation of heat accumulated in the heat sink by forced convection. Cooling of the heat sink and therefore of the electric motor and the module The power electronics module is improved. In addition, the blades are driven by the rotation of the rotor shaft and therefore do not require any additional mechanical elements. This minimizes the energy consumption required for cooling the electric motor and the power electronics module and also reduces potential sources of failure.

[0023] The housing may comprise an end wall extending transversely, preferably perpendicularly, to the longitudinal axis at a second end of the housing in the longitudinal direction, the housing comprising at least one inlet opening formed through the end wall to provide a flow of airflow from the exterior of the housing to the interior of the housing. The housing may for example comprise four inlet openings. The inlet openings may be regularly distributed around the longitudinal axis. The second end of the housing may be opposite the first end of the housing.

[0024] The housing may include at least one outlet opening at the first end for providing airflow from the inside of the housing to the outside of the housing. The housing may include a cylindrical wall extending along the longitudinal axis. Each outlet opening may be formed through the cylindrical wall. For example, the housing may include six outlet openings. The outlet openings may be regularly distributed about the longitudinal axis. Each inlet opening may be formed through the cylindrical wall adjacent a longitudinal end of the housing opposite the heat sink.

[0025] The cooling means may comprise at least one cooling circuit arranged on the periphery of the stator of the motor and / or on the periphery of the casing of the power electronics module. A cooling fluid may circulate to carry out a heat exchange with, where appropriate, the stator of the motor and / or the casing of the power electronics module. The cooling fluid may be oil or any other suitable heat transfer fluid. The cooling means comprising the combination of the heat sink and said at least one cooling circuit allow increased cooling of the stator of the electric motor and the casing of the power electronics module without increasing the size of the thruster. In addition, the presence of two separate members participating in the cooling allows redundancy of the cooling means.In other words, cooling of the electric motor and the power electronics module can be achieved even in the event of a failure of the cooling circuit or the heat sink.

[0026] The cooling means may comprise a cooling circuit arranged on the periphery of the stator of the electric motor and a cooling circuit arranged on the periphery of the housing of the power electronics module. Each cooling circuit may comprise at least one inlet nozzle and one outlet nozzle for the cooling fluid. Each cooling circuit may be formed integrally in a wall of the stator and / or the housing.

[0027] The electric motor may comprise N input connectors with N>1. Each input connector may be arranged on a radially outer face of the stator, at the first longitudinal end of the stator. The input connectors may be regularly distributed around the longitudinal axis.

[0028] The power electronics module may comprise N output connectors. Each output connector may be arranged on a radially outer face of the casing, at the first longitudinal end of the casing. The output connectors may be regularly distributed around the longitudinal axis. Each output connector of the power electronics module may be electrically connected, i.e. connected, to an input connector of the electric motor. Each output connector may be arranged longitudinally opposite an input connector of the motor to be electrically connected thereto. Each assembly formed by an input connector and an output connector connected together forms an electrical connection between the electric motor and the power electronics module. Each input connector and each output connector may be protected by a cover.

[0029] According to a preferred embodiment, N is equal to 6. Two circumferentially consecutive output connectors may be spaced apart from each other by an angle of 60° around the longitudinal axis. Two circumferentially consecutive input connectors may be spaced apart from each other by an angle of 60° around the longitudinal axis. The heat sink may comprise N groups of fins. The fins of each group may be arranged circumferentially between two circumferentially consecutive electrical connections.

[0030] Each output opening of the power electronics module housing can be arranged circumferentially between two circumferentially consecutive output connectors.

[0031] The electric motor may be a permanent magnet synchronous motor. The motor may be a three-phase motor connected in a star arrangement. Each input connector and each output connector may be three-phase. The power electronics module may comprise N inverters and a plurality of power modules. Each inverter can be connected to three power modules, each of which is connected to an output phase of one of the output connectors of the power electronics module. Each inverter and each power module is mounted on the housing of the power electronics module, in particular on a radially inner face or on a radially outer face of the housing. The inverters can be regularly distributed around the longitudinal axis. Similarly, the power modules can be regularly distributed around the longitudinal axis. The power modules can be arranged circumferentially alternately on the radially inner face and the radially outer face of the housing. Each inverter can convert a direct voltage supplied by a direct voltage source such as a battery into an alternating voltage. The power electronics module can allow the distribution of a power of between 400 kW and 1 MW.

[0032] According to another aspect, there is provided an aircraft comprising at least one propeller as described above. Brief description of the drawings

[0033] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which:

[0034] Figure 1 represents a perspective view of an assembly for electric propulsion according to the state of the art;

[0035] Figure 2 represents a schematic view in longitudinal section of an assembly for electric propulsion according to the present description;

[0036] Figure 3 represents an exploded perspective view of the assembly of Figure 2;

[0037] Figure 4 represents an exploded schematic sectional view of the assembly of Figure 2;

[0038] Figure 5 represents a schematic sectional view of a power electronics module of the assembly of Figure 2 in the section plane VV;

[0039] Figure 6 shows a schematic front view of a heat sink of the assembly of Figure 2. Description of the embodiments

[0040] Reference is now made to Figures 2 to 6. Figures 2 to 4 show a thruster for an aircraft with electric or hybrid propulsion. The thruster comprises an electric motor 10, a power electronics module 20 and means for cooling the electric motor 10 and the power electronics module 20.

[0041] The electric motor 10 may be a permanent magnet synchronous motor. The electric motor 10 may be a three-phase motor connected in a star arrangement. The motor comprises an annular stator 11 around a longitudinal axis X and a rotor arranged, here in part, radially inside the stator 11, to be driven in rotation around the longitudinal axis X. The rotor comprises a shaft 12 extending along the longitudinal axis X. The shaft 12 may drive a propeller of the thruster, possibly via a gearbox.

[0042] In this disclosure, the longitudinal direction corresponds to the direction of the longitudinal axis X. The longitudinal axis X coincides with an axis of rotation of the rotor parts of the thruster. Orientation qualifiers, such as "longitudinal", "radial" or "circumferential" are defined with reference to the longitudinal axis. A radial direction is a direction perpendicular to the longitudinal axis X. A circumferential direction, at a point distant from the longitudinal axis, corresponds to a direction perpendicular to the axial and radial directions.

[0043] Furthermore, unless otherwise specified, the adjectives "inner", "internal", "outer" and "external" are used with reference to a radial direction so that the inner / inner (i.e. radially inner / inner) part of an element is closer to the longitudinal axis than the outer / outer (i.e. radially outer / outer) part of the same element.

[0044] The power electronics module 20 is adapted to supply the electric motor 10 with electricity. The power electronics module 20 comprises an annular casing 21 which extends along the longitudinal axis X. The casing 12 is therefore hollow. In other words, the casing 21 defines a longitudinal passage. The casing 21 of the power electronics module 20 comprises a first end arranged longitudinally opposite a first end of the stator 11 of the electric motor 10. The first end of the stator 11 and the first end of the casing 21 are each considered in the longitudinal direction. The shaft 12 extends radially inside the casing 21 of the power electronics module 21. Also, the shaft 12 projects from a second longitudinal end of the casing 21 of the power electronics module 20 which is opposite the electric motor 10. The second end of the casing 21 is longitudinally opposite the first end.

[0045] The casing 21 comprises a cylindrical wall 22 which extends along the longitudinal axis X. The casing 21 also comprises an end wall 23 which extends perpendicular to the longitudinal axis X at the second end of the casing 21 in the longitudinal direction. The first end and the second end of the casing 21 coincide respectively with a first end and a second end of the cylindrical wall 22 (also considered in the longitudinal direction). The end wall 23 of the casing 21 here comprises an orifice for the passage of the shaft 12 of the rotor.

[0046] Remarkably, the stator 11 of the electric motor 10 and the casing 21 of the power electronics module 20 here have a section perpendicular to the longitudinal axis X having the same shape and the same dimensions. The stator 11 of the electric motor 10 is a cylinder of circular section extending along the longitudinal axis X. The casing 21 of the power electronics module 20 is also a cylinder of circular section extending along the longitudinal axis X. The circular section of the stator 11 has the same diameter as the circular section of the casing 21 of the power electronics module 20.

[0047] The housing 21 of the power electronics module 20 and the stator 11 of the electric motor 10 may be joined to each other at their respective first ends. The housing 21 may be connected to the stator 11 of the electric motor 10, for example by bolted connections.

[0048] The electric motor 10 here comprises six input connectors 13. The power electronics module 20 comprises six output connectors 26. Each output connector 26 of the power electronics module 20 is thus electrically connected, i.e. connected, to an input connector 13 of the electric motor 10 to enable the electric motor 10 to be supplied with power by the power electronics module 20. Each input connector 13 and each output connector 26 can be three-phase. Each assembly comprising an input connector 13 and an output connector 26 connected together therefore forms an electrical connection between the electric motor 10 and the power electronics module 20. Each electrical connection is here protected by a respective cover.

[0049] Each input connector 13 is arranged on a radially external face of the stator 11, at the first longitudinal end of the stator 11. Each output connector 26 is arranged on a radially external face of the casing 21, at the first longitudinal end of the casing 21. The output connectors 26 and the input connectors 13 are regularly distributed around the longitudinal axis X. Two circumferentially consecutive output connectors 26, respectively input connectors, are therefore spaced from each other by an angle of 60° around the longitudinal axis X. Each output connector 26 is also arranged longitudinally opposite an input connector 13 of the motor to be electrically connected thereto. This minimizes the wiring length.

[0050] The power electronics module 20 also comprises six inverters and a plurality of power modules 27, the latter being visible in particular in FIG. 5. Each inverter is connected to three power modules 27, each of which is connected to an output phase of one of the output connectors 26 of the power electronics module 20. The power electronics module 20 therefore comprises eighteen power modules 27 here. Each inverter and each power module 27 is mounted on the casing 21 of the power electronics module 20, in particular on a radially inner face or on a radially outer face of the casing 21. In particular, the power modules 27 are arranged circumferentially in an alternating manner on the radially inner face and the radially outer face of the casing 21. The inverters and the power modules 27 may also be regularly distributed around the longitudinal axis X.Each inverter converts a DC voltage supplied by a DC voltage source such as a battery into an AC voltage. The power electronics module 20 can enable the distribution of power of between 400 kW and 1 MW to the electric motor 10.

[0051] The cooling means firstly comprise a heat sink 30. The heat sink 30 is shown in isolation in FIG. 6.

[0052] The heat sink 30 is interposed longitudinally between the first end of the stator 11 of the electric motor 10 and the first end of the casing 21 of the power electronics module 20. The heat sink 30 therefore bears on the first end of the stator 11 of the electric motor 10 in a first direction of the longitudinal direction and on the first end of the casing 21 of the power electronics module 20 in a second direction of the longitudinal direction. The heat sink 30 comprises for this purpose at least a first face bearing on the first end of the stator 11 of the electric motor 10 and at least a second face, longitudinally opposite the first face, bearing on the first end of the casing 21 of the power electronics module 20.The heat sink 30 allows the heat generated by the electric motor 10 (represented by the arrows C1 in FIG. 2) and the heat generated by the power electronics module 20 (represented by the arrows C2 in FIG. 2) to be evacuated to the ambient air surrounding the motor and the power electronics module 20. The heat sink 30 also allows the heat to be evacuated passively. In this sense, the heat sink 30 can be described as passive. Indeed, the heat generated by the motor and the power electronics module 20 is transmitted to the heat sink 30 by thermal conduction due to the contact between the heat sink 30 and each of the motor and the power electronics module 20. The heat is then evacuated by convection with the ambient air. To se. To do this, the heat sink 30 comprises a radially external face 34 devoid of any contact with a conductive solid element, in particular the stator 11 of the motor 10 and / or the casing 21 of the power electronics module 20. The radially external face 34 of the heat sink 30 is therefore configured to allow heat transfer with ambient air external to the motor and to the power electronics module. In this respect, the heat sink 30 differs from active heat exchangers which comprise a working fluid circulating in a sealed conduit and for which the heat is evacuated by means of the working fluid. Thus, the heat sink 30 has the advantage of not requiring an external mechanical element to ensure its operation and advantageously does not present any risk of leaks. Such a heat sink 30 is therefore more reliable.

[0053] To improve heat exchange, the heat sink can be made of a material suitable for dissipating heat. Such a material advantageously has thermal conductivity allowing heat to be dissipated. The thermal conductivity can, for example, be greater than 45 W.nr 1 .K' 1 , preferably greater than 100 W.m' 1 .K' 1 , preferably still greater than 200 W.m' 1 .K' 1 , preferably still greater than 400 W.nr 1 .K' 1 The heat sink can be made of a metallic material, such as aluminum or copper.

[0054] The heat sink 30 here comprises a disc 31 which extends perpendicular to the longitudinal axis X. The disc 31 comprises at least a first face bearing on the first end of the stator 11 of the electric motor 10 and at least a second face, longitudinally opposite the first face, bearing on the first end of the casing 21 of the power electronics module 20. The first face and the second face of the disc 31 extend perpendicular to the longitudinal axis X. The first face and the second face of the disc 31 are, in the example, illustrated in contact respectively with the stator 11 and the casing 21 in the vicinity of a periphery of the disc 31. Also, the first face and the second face of the disc 31 may each comprise an annular strip around the longitudinal axis X which is in contact respectively with the stator 11 and the casing 21.The disc 31 of the heat sink, due to its circular shape, allows homogeneous heat evacuation around the longitudinal axis X (represented by the arrows C3 in Figure 6). Remarkably, the disc 31 has substantially the same diameter as the circular section of the stator 11 of the motor and the casing 21 of the power electronics module 20.

[0055] The radially external face 34 of the heat sink 30 here has a cylindrical shape of revolution around the longitudinal axis X.

[0056] The heat sink 30 also comprises at least one fin 32 extending radially outwards from the periphery of the disc 31, or here from the radially external face 34. In the example illustrated, the heat sink 30 comprises a plurality of fins 32 distributed regularly around the longitudinal axis X. The fins 32 of the heat sink 30 are arranged in groups G of at least two fins 32. Here, by way of example, each group G comprises five fins 32. The fins 32 of each group G may be arranged circumferentially between two circumferentially consecutive electrical connections. The heat sink 30 therefore comprises six groups G of fins 32. The fins 32 make it possible to increase the heat exchange surface by convection between the disc 31 and the ambient air, thus improving the performance of the heat sink 30.

[0057] Finally, the heat sink 30 comprises an opening 33 through which the rotor shaft 12 extends. The opening 33 is here centered on the longitudinal axis X. The opening 33 has a circular shape.

[0058] The cooling means further comprise an annular row of blades 40 secured to the shaft 12 of the rotor. The annular row of blades 40 is arranged radially inside the casing 21. The annular row of blades 40 is shaped to propel an air flow F onto the heat sink 30 when it is rotated about the longitudinal axis X via the shaft 12. A radially inner end of each blade 40 may be directly connected to the shaft 12. In other words, each blade 40 may extend radially outward from the shaft 12. According to a variant, a disk (or an annular platform) may be provided mounted on the shaft 12 and on which each of the blades 40 are mounted. Alternatively, a plurality of annular rows of blades 40 may be provided arranged longitudinally one after the other inside the casing 21, each of them being like that described in the case of the illustrated example.

[0059] The air flow F ventilated on the heat sink 30 makes it possible to improve the evacuation of the heat accumulated in the heat sink 30 by forced convection. The cooling of the heat sink 30 and therefore of the electric motor 10 and the power electronics module 20 is improved. In addition, the drive of the blades 40 is implemented by the rotation of the shaft 12 of the rotor and therefore does not require additional mechanical elements. This makes it possible to minimize the energy consumption necessary for cooling the electric motor 10 and the power electronics module 20 and this also makes it possible to reduce the sources of possible breakdowns.

[0060] In order to allow the air flow F to flow inside the casing 21, the latter comprises at least one inlet opening 24 and / or at least one outlet opening 25.

[0061] Each inlet opening 24 is formed through the end wall 23 to ensure a flow of the air flow F from the outside of the casing 21 to the inside of the casing 21. The casing 21 here comprises four inlet openings 24 by way of example. The inlet openings 24 are regularly distributed around the longitudinal axis X. Alternatively, each inlet opening 24 may be formed through the cylindrical wall 22 in the vicinity of the second longitudinal end of the casing 21.

[0062] Each outlet opening 25 is formed at the first end to ensure a flow of the air flow F from the inside of the casing 21 to the outside of the casing 21. Each outlet opening 25 is here formed through the cylindrical wall 22 of the casing 21. The casing 21 may for example comprise six outlet openings 25. Each outlet opening 25 may be circumferentially arranged between two circumferentially consecutive outlet connectors 26. The outlet openings 25 may be regularly distributed around the longitudinal axis X.

[0063] The cooling means also comprise a first cooling circuit arranged on the periphery of the stator 11 of the motor and a second cooling circuit 50 on the periphery of the casing 21 of the power electronics module 20. A cooling fluid circulates in each of the cooling circuits to carry out a heat exchange with, respectively, the stator 11 of the motor and / or the casing 21 of the power electronics module 20. As visible in FIG. 5, the second cooling circuit 50 is formed integrally in the cylindrical wall 22 of the casing 21. Each cooling circuit comprises at least one inlet nozzle 51 and one outlet nozzle 52 for the cooling fluid. Each cooling circuit is therefore independent. In other words, the first cooling circuit and the second cooling circuit 50 operate in parallel.Alternatively, the first cooling circuit and the second cooling circuit 50 may be in series, i.e. in fluid communication with each other. For example, the fluid may first circulate in the second cooling circuit 50 and then circulate in the first cooling circuit. In other words, the first cooling circuit and the second cooling circuit 50 may form a single cooling circuit.

[0064] The cooling means comprising the combination of the heat sink 30 and the cooling circuits allow increased cooling of the stator 11 of the electric motor 10 and the casing 21 of the power electronics module 20 without increasing the size of the thruster. In addition, the presence of two members separate cooling circuits allowing redundancy of the cooling means. In other words, cooling of the electric motor 10 and the power electronics module 20 can be achieved even in the event of failure of one of the cooling circuits or the heat sink 30.

Claims

Claims

1. A propeller for an aircraft, the propeller comprising: - an electric motor (10) which comprises an annular stator (11) around a longitudinal axis (X) and a rotor arranged, at least in part, radially inside the stator (11), to be driven in rotation around the longitudinal axis (X), - a power electronics module (20) adapted to supply the electric motor (10) with electricity, the power electronics module (20) comprising an annular casing (21) which extends along the longitudinal axis (X), the casing (21) of the power electronics module (20) comprising a first end arranged longitudinally opposite a first end of the stator (11) of the electric motor (10), - means for cooling the electric motor (10) and the power electronics module (20), the cooling means comprising a heat sink (30) interposed longitudinally between the first end of the stator (11) of the electric motor (10) and the first end of the casing (21) of the power electronics module (20).

2. Propellant according to the preceding claim, in which the heat sink (30) comprises a disc (31) which extends perpendicular to the longitudinal axis (X), the disc (31) comprising at least a first face bearing on the first end of the stator (11) of the electric motor (10) and at least a second face, longitudinally opposite the first face, bearing on the first end of the casing (21) of the power electronics module (20).

3. A thruster according to the preceding claim, wherein the heat sink (30) comprises at least one fin (32) extending radially outwards from the periphery of the disc (31), the heat sink (30) preferably comprising a plurality of fins (32) distributed regularly around the longitudinal axis (X), the fins (32) of the heat sink (30) being more preferably arranged in groups (G) of at least two fins (32).

4. A thruster according to any preceding claim, wherein the rotor comprises a shaft (12) extending along the longitudinal axis (X), the shaft (12) extending radially inside the housing (21) of the power electronics module (20), the heat sink (30) comprising an opening (33) through which the shaft (12) of the rotor extends.

5. Propellant according to the preceding claim, in which the cooling means comprise at least one annular row of blades (40) integral with the shaft (12) of the rotor, the annular row of blades (40) being arranged radially inside the casing (21), the annular row of blades (40) being shaped to propel an air flow (F) on the heat sink (30) when it is rotated about the longitudinal axis (X) by means of the shaft (12).

6. A thruster according to the preceding claim, wherein the casing (21) comprises an end wall (23) which extends transversely, preferably perpendicularly, to the longitudinal axis (X) at a second end of the casing (21) in the longitudinal direction, the casing (21) comprising at least one inlet opening (24) formed through the end wall (23) to ensure a flow of the air flow (F) from the outside of the casing (21) towards the inside of the casing (22).

7. A thruster according to claim 5 or 6, wherein the casing (21) comprises at least one outlet opening (25) at the first end to ensure a flow of the air flow (F) from the inside of the casing (21) to the outside of the casing (21).

8. Propellant according to any one of the preceding claims, in which the cooling means comprise at least one cooling circuit (50) arranged on the periphery of the stator (11) of the motor (10) and / or on the periphery of the casing (21) of the power electronics module (20), and in which a cooling fluid circulates to carry out a heat exchange with, where appropriate, the stator (11) of the motor (10) and / or the casing (21) of the power electronics module (20).

Images