FR3150507A1 - Fuel feeding system for a fuel circuit - Google Patents

Abstract

The invention relates to a fuel feeding system (1) for a fuel circuit (C) comprising: - a hydraulic subassembly (2) comprising a rotating part, capable of generating a circulation of the fuel (C), mounted in a first enclosure (E1); - an electric motor (3), capable of driving the hydraulic subassembly (2); - a driven rotor (4) mechanically coupled to the rotating part of the hydraulic subassembly (2) and mounted in the first enclosure (E1) and; - a driving rotor (6) mechanically coupled to a rotor of the electric motor (3) and mounted in a second enclosure (E2), the driving rotor (6a) and the driven rotor (4a) being magnetically coupled. Abstract figure: Figure 2

Description

Fuel feeding system for a fuel circuit

The present invention relates to the field of fuel supply systems for a fuel circuit, in particular for an aircraft turbomachine.

In a known manner, an aircraft comprises one or more turbomachines comprising a combustion chamber into which air and fuel enter, configured to react together following a combustion reaction, so as to release the energy necessary for the thrust of the aircraft. The air comes from outside the turbomachine and is guided towards the combustion chamber by an air stream. The fuel comes from a fuel circuit opening into the combustion chamber.

• un ou plusieurs réservoirs de stockage du carburant,
• une pompe de gavage,
• un filtre de retenue des particules solides contenues dans le carburant,
• une pompe mécanique,
• une vanne de dosage d’un débit massique de carburant et
• un ou plusieurs injecteurs pour pulvériser le débit massique dans la chambre de combustion.

The fuel circuit can traditionally include, in particular depending on the direction of fuel flow:

• one or more fuel storage tanks,
• a fuel pump,
• a filter for retaining solid particles contained in the fuel,
• a mechanical pump,
• a metering valve for a mass flow of fuel and
• one or more injectors to spray the mass flow into the combustion chamber.

If there are multiple fuel storage tanks, one or more transfer pumps are additionally used to transfer fuel between the fuel storage tanks.

Particularly known are fuel and transfer pumps, known as "submersible motor" pumps, in which an electric drive motor is immersed in the fuel, to ensure cooling of the electric motor and lubrication of the rotating guide bearings of the rotor of the electric motor.

The electric motor is said to be "submerged" in that the fuel circulates in the cavity of the motor in contact with the rotor and the stator.

The electric motor is typically an asynchronous motor connected directly to the aircraft's AC electrical network, with a voltage of 115VAC, an acronym for "Volts Alternating Current" in English, or a permanent magnet synchronous motor controlled by an electronic control unit, also known as "ECU" for "Electronic Command Unit (ECU)" in English, supplied with a DC voltage typically of 270VDC, an acronym for "Volts Direct Current" in English, or an AC voltage of 115VAC.

One of the current challenges for reducing fuel consumption in aircraft is to reduce the on-board mass of aircraft, particularly that of wiring. One possibility for reducing the cross-section of wiring while maintaining electrical power is to work with higher voltages, typically a direct voltage of 540VDC or more, or an alternating voltage of 230VAC or more.

Such voltages associated with traditional construction methods of wound motors have the disadvantage of causing partial discharges, namely the appearance of a partial short circuit within the cavities present in the insulators between two electrical conductors due to the presence of a strong local electric field ionizing the conductive gas. Such partial discharges can in the long term deteriorate the insulators between the electrical conductors and ultimately lead to electric arcs.

In submersible pump designs, such partial discharges, in contact with fuel vapors, are likely to cause a risk of ignition and/or explosion. Such a risk is increased by the fact that submersible pumps are in a non-pressurized area, whose pressure can vary from approximately 1013HPa on the ground to approximately 100HPa at 16km altitude in flight.

Low pressures are more likely to cause partial discharges according to Paschen's law. In fact, a decrease in pressure lowers the voltage at which partial discharges occur.

To protect against this, according to the CS 25.981 standard, it is known to add a set of protective barriers in the architectures of submersible motor pumps to make the presence of ignition sources extremely unlikely, in particular that it does not result from a simple failure. The rotor and the stator are, for example, covered with one or more layers of electrically insulating coating, such as an overmolding and an impregnation resin.

The body in which the motor is mounted is also explosion-proof. However, such barriers are likely to be insufficient to demonstrate that the risks of ignition remain extremely improbable in the context of high voltage power supply, because these would not be independent of the degradation linked to partial discharges.

In this context, the invention aims to maintain a level of safety in accordance with standard CS 25.981, when the motor of the aircraft electric motor pump is supplied with voltages likely to cause partial discharges, in particular intended to be supplied by high voltages.

Another disadvantage of fuel booster and transfer pumps is related to their maintenance. To ensure their maintenance without having to drain the tanks, it is known, according to the prior art as notably shown schematically in longitudinal section in , to mount a fuel booster pump 100, an electric motor 110, and in some cases an electronic control unit 120, in a cartridge 140, configured to be installed in a housing 150, also known to those skilled in the art as a “canister”, attached to the fuel tank 130 C. The housing 150 includes a fuel inlet and outlet C equipped with shut-off valves. Once the cartridge 140 is installed, the fuel C flows from the inlet to the outlet in the housing 150 via the cartridge 140.

During a maintenance operation, the shut-off valves are closed and the cartridge 140 is uninstalled. In practice, during such a maintenance operation, fuel C residues located between the cartridge 140 and the housing 150 are likely to be projected onto the operators, the surrounding equipment and onto the ground, which is not desired.

The invention thus also aims to reduce the risk of fuel projection during a maintenance operation on an electric motor fuel feed pump, in particular for an aircraft turbomachine.

PRESENTATION OF THE INVENTION

• un sous-ensemble hydraulique comprenant une pièce rotative, apte à générer une circulation du carburant, montée dans une première enceinte, en particulier comportant au moins une ouverture d’entrée et au moins une ouverture de sortie de circulation du carburant, et
• un moteur électrique, apte à d’entraîner le sous-ensemble hydraulique.

The invention relates to a fuel feeding system for a fuel circuit, in particular of an aircraft turbomachine, comprising:

• a hydraulic subassembly comprising a rotating part, capable of generating fuel circulation, mounted in a first enclosure, in particular comprising at least one inlet opening and at least one outlet opening for fuel circulation, and
• an electric motor, capable of driving the hydraulic subassembly.

• un rotor mené couplé mécaniquement à la pièce rotative du sous-ensemble hydraulique et monté dans la première enceinte, et
• un rotor menant couplé mécaniquement à un rotor du moteur électrique et monté dans une deuxième enceinte,
• le rotor menant et le rotor mené étant couplés magnétiquement.

The invention is remarkable in that the fuel feeding system comprises:

• a driven rotor mechanically coupled to the rotating part of the hydraulic subassembly and mounted in the first enclosure, and
• a driving rotor mechanically coupled to a rotor of the electric motor and mounted in a second enclosure,
• the driving rotor and the driven rotor being magnetically coupled.

Such a fuel-feeding system ensures increased safety against the risk of partial discharge, particularly in the presence of high power supply voltages, such as a direct voltage of 540VDC or an alternating voltage of 230VAC.

According to one aspect of the invention, the fuel feeding system is such that the second enclosure is sealed in a fuel-tight manner, defining in particular a pressurized cavity.

In addition, the second enclosure is capable of housing at least the rotor and one stator of the electric motor.

Finally, the second enclosure is likely to be fixed against the first enclosure.

By virtue of the invention, the electric motor driving the hydraulic subassembly extends into a pressurized cavity free of fuel. The electric motor is thus protected from low pressures at altitude, for which the risk of partial discharge occurring is greater, due to the reduction in the voltage at which partial discharges occur at altitude.

Additionally, the electric motor is conveniently confined in a fuel-free zone, reducing the risk of fuel vapors igniting from a spark.

The fuel feeding system also has the advantage of facilitating maintenance of the electric motor. It is sufficient to dismantle the second enclosure, which does not require draining the fuel from the first enclosure and avoids any risk of projection or leakage during a maintenance operation.

According to one aspect of the invention, the fuel feeding system comprises a fuel-tight inner wall, interposed between the driving rotor and the driven rotor, in particular common to the first enclosure and the second enclosure. Such an inner wall forms the air gap between the driven rotor and the driving rotor. The inner wall is shared between the first enclosure and the second enclosure to reduce the on-board mass.

• le sous-ensemble hydraulique comprend un corps de pompe entourant la pièce rotative de pompe, la paroi interne étant fixée de manière étanche sur le corps de pompe de manière à former ensemble la première enceinte, et/ou
• le moteur électrique comprend une paroi de moteur entourant le rotor et un stator du moteur électrique, la paroi de moteur étant fixée de manière étanche sur la première enceinte de manière à former la deuxième enceinte.

According to other aspects of the invention, considered individually or in combination:

• the hydraulic subassembly comprises a pump body surrounding the rotating pump part, the inner wall being fixed in a sealed manner to the pump body so as to together form the first enclosure, and/or
• the electric motor comprises a motor wall surrounding the rotor and a stator of the electric motor, the motor wall being sealingly attached to the first enclosure so as to form the second enclosure.

Such a housing- and cartridge-free architecture reduces the on-board mass. The attachment of the inner wall and the motor wall to the pump body forms a pressurized, fuel-free cavity for the rotor and stator of the electric motor.

• le sous-ensemble hydraulique s’étend dans un logement, la paroi interne étant fixée de manière étanche sur le logement de manière à former ensemble la première enceinte, et/ou
• le moteur électrique s’étend dans une cartouche, la cartouche étant fixée de manière étanche sur la première enceinte de manière à former la deuxième enceinte.

According to other aspects of the invention, considered individually or in combination, the fuel feeding system comprises:

• the hydraulic subassembly extends into a housing, the internal wall being fixed in a sealed manner to the housing so as to together form the first enclosure, and/or
• the electric motor extends into a cartridge, the cartridge being sealed to the first enclosure so as to form the second enclosure.

The attachment of the inner wall and cartridge to the housing forms a pressurized, fuel-free cavity for the electric motor. The use of a cartridge facilitates disassembly during maintenance. In addition, the cartridge can form an additional explosion-proof barrier, in addition to the motor wall.

According to one aspect of the invention, the electric motor is electrically supplied with high direct or alternating voltage, preferably with a direct voltage greater than 320VDC or an alternating voltage greater than 203VAC, preferably with a direct voltage greater than 530VDC or an alternating voltage greater than 220VAC.

Such high electrical voltages advantageously make it possible to reduce the on-board mass of the electrical wiring but have the disadvantage of causing partial discharges, which justifies a dry motor architecture and the mass gain linked to the integration of a magnetic coupling device, according to the invention.

According to one aspect of the invention, the second enclosure is explosion-proof, to meet aeronautical standards relating to electric motor aircraft pumps in terms of safety. The second enclosure is in practice hermetic, which makes it explosion-proof.

According to one aspect of the invention, the second enclosure is fixed against the first enclosure, in particular by removable fixing members, in particular in the form of screws, to ensure maintenance of the electric motor.

According to one aspect of the invention, the removable fixing members are associated with at least one sealing gasket. This makes it possible to obtain a second sealed enclosure and helps to form a pressurized cavity.

The invention also relates to an aircraft turbomachine comprising a fuel circuit comprising a fuel supply system as described above.

The invention also relates to a method of using an aircraft turbomachine in flight as described above, in which the rotor of the electric motor of the fuel boosting system drives, from the second enclosure defining a pressurized cavity, the rotating part of the hydraulic subassembly via the driving rotor and the driven rotor magnetically coupled.

The invention also relates to a method of maintaining the electric motor of a fuel supply system as described above, consisting of dismantling the second enclosure from the first enclosure.

PRESENTATION OF FIGURES

• La est une représentation schématique en coupe longitudinale d’une pompe de gavage de carburant dans une turbomachine selon l’art antérieur ;
• La est une représentation schématique en coupe longitudinale d’un système de gavage de carburant selon une première forme de réalisation de l’invention ;
• La est une représentation schématique en coupe longitudinale d’un système de gavage de carburant selon une deuxième forme de réalisation de l’invention ;
• La est une représentation en perspective du système de gavage de carburant de la ; et
• La , la et la sont des représentations en perspective éclatée d’un accouplement d‘une pièce rotative d’un sous-ensemble hydraulique au rotor d’un moteur électrique selon trois formes de réalisation de l’invention.

The invention will be better understood upon reading the description which follows, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects, in which:

• There is a schematic representation in longitudinal section of a fuel booster pump in a turbomachine according to the prior art;
• There is a schematic representation in longitudinal section of a fuel feeding system according to a first embodiment of the invention;
• There is a schematic representation in longitudinal section of a fuel feeding system according to a second embodiment of the invention;
• There is a perspective representation of the fuel supply system of the ; And
• There , there and the are exploded perspective representations of a coupling of a rotating part of a hydraulic subassembly to the rotor of an electric motor according to three embodiments of the invention.

It should be noted that the figures set out the invention in detail to implement the invention, the figures can of course be used to better define the invention if necessary.

DETAILED DESCRIPTION OF THE INVENTION

As previously described, an aircraft turbomachine comprises a combustion chamber into which air and fuel enter, configured to react together following a combustion reaction, so as to release the energy necessary for the thrust of the aircraft. The air comes from outside the turbomachine and is guided towards the combustion chamber by an air stream. The fuel comes from a fuel circuit opening into the combustion chamber.

• un ou plusieurs réservoirs de stockage du carburant,
• une pompe de gavage, configurée pour mettre en mouvement le carburant C du réservoir,
• un filtre de retenue des particules solides contenues dans le carburant,
• une pompe mécanique,
• une vanne de dosage d’un débit massique de carburant et/ou
• un ou plusieurs injecteurs pour pulvériser le débit massique dans la chambre de combustion.

The fuel circuit can traditionally include, in particular depending on the direction of fuel flow:

• one or more fuel storage tanks,
• a fuel pump, configured to set the fuel C in motion from the tank,
• a filter for retaining solid particles contained in the fuel,
• a mechanical pump,
• a metering valve for a mass flow of fuel and/or
• one or more injectors to spray the mass flow into the combustion chamber.

If there are multiple fuel storage tanks, one or more transfer pumps are additionally used to transfer fuel between the fuel storage tanks.

Figures 2 and 3 are schematic representations in longitudinal section of a fuel feeding system according to a first form and a second embodiment of the invention.

More particularly, with reference to FIGS. 2 and 3, a fuel booster system 1 according to the invention is configured to be mounted in a fuel circuit, in particular intended to supply an aircraft turbomachine. The fuel booster system 1 comprises a hydraulic subassembly 2 and an electric motor 3, intended to drive the hydraulic subassembly 2.

The hydraulic subassembly 2 of the fuel feeding system 1 comprises a rotating part 21, capable of ensuring a drive of the fuel C, mounted in a first enclosure E1 comprising an inlet opening 12 and an outlet opening 13, in particular provided with valves, capable of allowing a circulation of the fuel C.

The fuel booster system 1 according to the invention typically designates a booster pump or a fuel circuit transfer pump.

• un rotor mené 4, apte à être couplé mécaniquement à la pièce rotative 21 du sous-ensemble hydraulique 2, monté dans la première enceinte E1, et
• un rotor menant 6, apte à être couplé mécaniquement à un rotor 31 du moteur électrique 3, monté dans une deuxième enceinte E2,
• le rotor menant 6 et le rotor mené 4 étant couplés magnétiquement.

According to the invention, as illustrated in Figures 2 and 3, the fuel feeding system 1 also comprises:

• a driven rotor 4, capable of being mechanically coupled to the rotating part 21 of the hydraulic subassembly 2, mounted in the first enclosure E1, and
• a driving rotor 6, capable of being mechanically coupled to a rotor 31 of the electric motor 3, mounted in a second enclosure E2,
• the driving rotor 6 and the driven rotor 4 being magnetically coupled.

According to one aspect of the invention, the second enclosure E2 is sealed against fuel C and defines in particular a pressurized cavity, in which are mounted at least the rotor 31 and a stator 32 of the electric motor 3. According to a particular embodiment of the invention, the second enclosure E2 is fixed against the first enclosure E1.

The fuel feeding system 1 according to the invention is a dry engine type architecture unlike the submerged engine architectures of the prior art.

The electric motor 3 preferably extends into the fuel-free pressurized cavity formed by the second enclosure E2. It is specified that a pressurized cavity designates a sealed closed space in which a value of the pressure of the sealed closed space is independent of the external atmospheric pressure.

Furthermore, the first enclosure E1 ensures the circulation of the fuel C in the hydraulic subassembly 2, the absolute pressure of which is dependent, in particular, on the external atmospheric pressure. The electric motor 3 ensures the driving of the rotating part 21, in particular a pump, via a contactless magnetic coupling device. For this purpose, the driving rotor 6 and the driven rotor 4 extend respectively in the second enclosure E2 and the first enclosure E1 which form the air gap.

Thus, according to the invention, the fuel C is advantageously isolated from the high electrical voltages applied to the electric motor 3.

There is a perspective representation of the fuel supply system 1 of the .

More particularly, as illustrated in the , the hydraulic subassembly 2 comprises the rotating part 21, extending in particular along a longitudinal axis X. The rotating part 21 may be a paddle wheel.

The rotating part 21 is mounted in a pump body 20. The pump body 20 is fixed, and may correspond to a wall of the hydraulic subassembly 2 in which the fuel C circulates. The pump body 20 comprises an inlet opening 12 and an outlet opening 13 respectively ensuring a supply and a discharge of the fuel C.

The hydraulic subassembly 2 is, by way of non-limiting example, in the form of a centrifugal wheel, in particular of the radial flow type, in particular of the self-priming type. The operation of such a hydraulic subassembly 2 is known and is not detailed further.

As illustrated in the , the rotating part 21 is coupled in rotation to the driven rotor 4 via at least one shaft 24, capable of extending along the longitudinal axis X. The driving rotor 6 is coupled in rotation to the rotor 31 of the electric motor 3, via a shaft 33, capable of extending along the longitudinal axis X.

In the example presented, the driving rotor 6 is rotationally integral with the rotor 31 of the electric motor 3. The rotor 31 of the electric motor 3 drives, in particular from the pressurized cavity, the rotating part 21 of the feed pump via the driving rotor 6 and the driven rotor 4, in particular magnetically coupled.

As illustrated in the , the stator 32 of the electric motor 3 extends radially around the rotor 31, along the longitudinal axis X. In addition, the electric motor 3 comprises a motor wall 30 surrounding the stator 32. The motor wall 30 may be explosion-proof and may comprise aluminum.

The electric motor 3 of the fuel booster system 1 may be in the example of FIGS. 2 and 3 in the form of a permanent magnet synchronous motor, also designated by the acronym “PMSM” for “Permanent Magnets Synchronous Motor” in English, capable of being connected to the electrical network via an electronic control unit 9, also designated by the acronym “ECU” for “Electronic Command Unit” in English.

Alternatively, the electric motor 3 may be in the form of an asynchronous motor suitable for direct connection to the electrical network.

The operation of the electric motor 3 is known and is not detailed further.

The invention is particularly suitable for an electric motor 3 powered by high DC or AC electrical voltages. Indeed, the pressurized cavity significantly reduces the risk of partial discharges occurring in flight. More specifically, the second enclosure E2 makes it possible, during the flight, to maintain the atmospheric pressure on the ground in the pressurized cavity, namely approximately 1013 HPa.

The electric motor 3 is thus protected from the low pressures observed at altitude, which can reach approximately 100 HPa at an altitude of 16 km. However, the risk of partial discharges occurring increases when the pressure decreases since, according to Paschen's law, the voltage threshold for the occurrence of partial discharges decreases with pressure.

It is specified that a partial discharge designates the appearance of a partial short circuit within the cavities present in insulators between two electrical conductors due to the presence of a strong local electric field ionizing a conductive gas present between the two conductors.

The invention finds a particular application, in the aeronautical field, for a voltage greater than 320VDC, in particular greater than 530VDC, in particular equal to 540VDC.

For a three-phase alternating voltage, the invention finds a particular application, in the aeronautical field, for a voltage greater than 203VAC, in particular greater than 220VAC, in particular equal to 230VAC.

The use of such high voltages has the advantage of reducing the mass of the electrical cables on board an aircraft but presents a risk of the occurrence of partial discharges, which the invention makes it possible to avoid. The invention thus makes it possible to increase safety by preserving the insulation of the electrical conductors of the electric motor 3 and by reducing the risk of electric arcing. In addition, the invention makes it possible to keep the electric motor 3 out of reach of the fuel zones.

The invention is also suitable for electric motors 3 supplied by standard voltages, namely direct voltages less than or equal to 270VDC or alternating voltages less than or equal to 115VAC.

Figures 2 and 4 illustrate a first embodiment of the invention in which the motor wall 30 is fixed to the pump body 20, in the example presented along the longitudinal axis X.

The feeding system 1 also comprises an internal wall 5, in particular fixed to the pump body 20, in particular along the longitudinal axis X. The internal wall 5 extends in a space delimited by the pump body 20 and by the motor wall 30. In such a configuration, the internal wall 5 delimits, in particular on either side along the longitudinal axis X, the first enclosure E1 and the second enclosure E2. The internal wall 5 extends, in the example presented, radially inwardly relative to the motor wall 30.

In the first embodiment illustrated in Figures 2 and 4, the first enclosure E1 is formed by the pump body 20 and the inner wall 5. The first enclosure E1 houses the rotating part 21 of the feed pump, the driven rotor 4 and the shaft 24 connecting the rotating part 21 and the driven rotor 4. The second enclosure E2 is formed by the inner wall 5 and the motor wall 30. The second enclosure E2 houses the rotor 31 and the stator 32 of the electric motor 3, the driving rotor 6 and the shaft 33 connecting the driving rotor 6 and the rotor 31 of the electric motor 3.

The inner wall 5 is thus common, according to the particular example of relationship presented, to the first enclosure E1 and to the second enclosure E2. More particularly, the inner wall 5 extends between the driving rotor 6 and the driven rotor 4a magnetically coupled.

In the first embodiment illustrated in FIGS. 2 and 4, the motor wall 30 and the internal wall 5 are respectively fixed to the pump body 20 by fixing members 7, 8 ensuring a sealed assembly. Such a configuration helps to form the pressurized cavity of the second enclosure E2.

Such fixing members 7, 8 are for example screws, preferably completed by a sealing gasket, for example made of fluorosilicone. The fixing members 7, 8 are also removable to form a sealed and removable assembly, in order to allow the second enclosure E2 to be dismantled in particular during a maintenance operation of the electric motor 3.

According to the invention, there is no need to drain the fuel C from the first enclosure E1 which remains in place during the maintenance operation. The risk of fuel C leakage and projection, according to the prior art fuel pumps, no longer exists thanks to the presence of the internal wall 5.

There illustrates a second embodiment of the invention in which the fuel supply system 1 further comprises a housing 11, also referred to as the canister, and a cartridge 10.

The housing 11 is fixed to a fuel tank 40 C, in particular to a wall of the fuel tank 40 C. The housing 11 delimits an open cavity, in particular bell-shaped, in which the hydraulic subassembly 2, the driven rotor 4 and the shaft 24 connecting the hydraulic subassembly 2, in particular the rotating part 21, and the driven rotor 4 are mounted.

The housing 11 comprises an inlet opening 12 and an outlet opening 13, in particular provided with valves, capable of allowing circulation of the fuel C in the hydraulic subassembly 2.

The cartridge 10 houses the driving rotor 6, the electric motor 3 and the shaft 33 connecting the driving rotor 6 and the electric motor 3, in particular the rotor 31 of the electric motor 3. In addition, the cartridge 10 can also house the electronic control member 9, as shown in the .

The cartridge 10 is fixed on the housing 11, in particular as shown in the example of the , along the longitudinal axis X. The cartridge 10 may comprise aluminum.

In the second embodiment illustrated in , the feeding system 1 comprises, in a manner similar to the first embodiment, an internal wall 5, in particular fixed to the housing 11, in particular along the longitudinal axis X. The internal wall 5 extends in a space delimited by the housing 11 and the cartridge 10. In such a configuration, the internal wall 5 delimits, in particular on either side along the longitudinal axis X, the first enclosure E1 and the second enclosure E2. The internal wall 5 extends, in the example presented, in a radially inward manner relative to the housing 11.

In the second embodiment illustrated in the , the first enclosure E1 is formed by the housing 11 and the internal wall 5. The second enclosure E2 is formed by the internal wall 5 and the cartridge 10.

Similar to the first embodiment, the inner wall 5 is common to the first enclosure E1 and the second enclosure E2. More particularly, the inner wall 5 extends between the magnetically coupled driving rotor 6 and the driven rotor 4.

As with the first embodiment, the cartridge 10 and the internal wall 5c are respectively fixed to the housing 11 by fixing members 7, 8 ensuring a sealed assembly. Such a configuration helps to form the pressurized cavity of the second enclosure E2,

Such fixing members 7, 8 are, for example, screws, preferably completed by a sealing gasket, for example made of fluorosilicone. The fixing members 7, 8 are also removable to form a sealed and removable assembly, in order to allow the second enclosure E2 to be dismantled in particular during a maintenance operation of the electric motor 3.

According to one aspect of the invention, the driven rotor 4 and the driving rotor 6 are of the permanent magnet type. Alternatively, the driven rotor 4 and the driving rotor 6 comprise a ferromagnetic material with hysteresis. The driven rotor 4 and the driving rotor 6 may also comprise a structure made of a magnetic material such as stainless steel.

The internal wall 5 may comprise a non-magnetic material, in particular polyetheretherketone.

Figures 5, 6 and 7 are exploded perspective views of a coupling of the rotating part 21 of the hydraulic subassembly 2 to the rotor 31 of the electric motor 3 according to three embodiments of the invention. More particularly, Figures 5, 6 and 7 illustrate three possible configurations for the driven rotor 4, the inner wall 5 and the driving rotor 6.

In the configuration of the , the driven rotor 4 extends radially inwardly relative to the driving rotor 6 along the longitudinal axis X.

In the configuration of the , the driving rotor 6 extends radially inwardly relative to the driven rotor 4 along the longitudinal axis X.

For the configurations of Figures 5 and 6, the magnetic coupling is radial. The inner wall 5 preferably comprises a bell shape.

In the configuration of the , the magnetic coupling is axial along the longitudinal axis X, the internal wall 5 preferably having a disc shape, as shown in the , or bell, as shown on the .

The configurations of Figures 5, 6 and 7 are each compatible with the two embodiments of Figures 2 to 4.

• une étape d’alimentation, au cours de laquelle le moteur électrique 3 est alimenté électriquement, notamment à partir d’une commande de débit de carburant C, notamment de l’organe de commande électronique 9 ;
• une étape d’entraînement du moteur, au cours de laquelle le rotor 31 du moteur électrique 3 est entraîné magnétiquement en rotation ;
• une étape d’entraînement du rotor menant, au cours de laquelle le rotor menant 6 est entraîné mécaniquement dans la deuxième enceinte E2 ; et
• une étape d’entraînement du rotor mené, au cours de laquelle le rotor mené 4 est entraîné magnétiquement en rotation dans la première enceinte E1 à partir de la rotation du rotor menant 6 dans la deuxième enceinte E2.

In reference to the , a method of using a fuel booster system 1 according to any of the described embodiments comprises at least:

• a power supply step, during which the electric motor 3 is electrically powered, in particular from a fuel flow control C, in particular from the electronic control member 9;
• a motor drive step, during which the rotor 31 of the electric motor 3 is magnetically driven in rotation;
• a driving rotor drive step, during which the driving rotor 6 is mechanically driven in the second enclosure E2; and
• a driven rotor driving step, during which the driven rotor 4 is magnetically driven into rotation in the first enclosure E1 from the rotation of the driving rotor 6 in the second enclosure E2.

As a result, the driven rotor 4 drives the rotating part 21 of the fuel pump to circulate the fuel C from the inlet opening 12 to the outlet opening 13, in order to obtain a controlled fuel flow rate C.

Claims (11)

Fuel feeding system (1) for a fuel circuit (C), in particular of an aircraft turbomachine, comprising:

• a hydraulic subassembly (2) comprising a rotating part (21), capable of generating a circulation of the fuel (C), mounted in a first enclosure (E1), and
• an electric motor (3), capable of driving the hydraulic subassembly (2),
• the fuel feeding system (1) being characterized in that it comprises a driven rotor (4) mechanically coupled to the rotating part (21) of the hydraulic subassembly (2) and mounted in the first enclosure (E1), and a driving rotor (6) mechanically coupled to a rotor (31) of the electric motor (3) and mounted in a second enclosure (E2), the driving rotor (6) and the driven rotor (4) being magnetically coupled.

Fuel feeding system (1) according to claim 1, in which the second enclosure (E2) is sealed against the fuel (C), in particular defining a pressurized cavity. Fuel feeding system (1) according to any one of the preceding claims, in which an internal wall (5) impervious to the fuel (C) is interposed between the driving rotor (6) and the driven rotor (4), in particular common to the first enclosure (E1) and to the second enclosure (E2). Fuel feeding system (1) according to claim 3, wherein:

• the hydraulic subassembly (2) comprises a pump body (20) surrounding the rotating part (21), the internal wall (5) being fixed in a sealed manner to the pump body (20) so as to form the first enclosure (E1), and/or
• the electric motor (3) comprises a motor wall (30) surrounding the rotor (31) and a stator (32) of the electric motor (3), the motor wall (30) being fixed in a sealed manner to the first enclosure (E1) so as to form the second enclosure (E2).

Fuel feeding system (1) according to claim 3, wherein:

• the hydraulic subassembly (2) extends in a housing (11), the internal wall (5) being fixed in a sealed manner to the housing (11) so as to form the first enclosure (E1), and/or
• the electric motor (3) extends into a cartridge (10), the cartridge (10) being fixed in a sealed manner to the first enclosure (E1) so as to form the second enclosure (E2).

Fuel feeding system (1) according to any one of the preceding claims, wherein the electric motor (3) is electrically supplied with high direct or alternating voltage, preferably with a direct voltage greater than 320VDC or an alternating voltage greater than 203VAC. Fuel feeding system (1) according to any one of the preceding claims, wherein the second enclosure (E2) is explosion-proof. Fuel feeding system (1) according to any one of the preceding claims, in which the second enclosure (E2) is fixed against the first enclosure (E1), in particular by removable fixing members (7, 8). Fuel feeding system (1) according to claim 8, in which the fixing members (8) are associated with at least one seal. Aircraft turbomachine comprising a fuel circuit (C) comprising a fuel boosting system (1) according to one of the preceding claims. Method of using an aircraft turbomachine in flight according to claim 10, in which the rotor (31) of the electric motor (3) of the fuel supply system (1) drives, from the second enclosure (E2) defining a pressurized cavity, the rotating part (21) of the hydraulic subassembly (2) via the driving rotor (6) and the driven rotor (4) magnetically coupled.