Fuel boost system for a fuel circuit

Abstract

The invention relates to a fuel boost system (1) for a fuel circuit, the system comprising: - a hydraulic subassembly (2) comprising a rotary part capable of circulating the fuel (C), which part is mounted in a first chamber (E1); - an electric motor (3) capable of driving the hydraulic subassembly (2); - a driven rotor (4) mechanically coupled to the rotary part of the hydraulic subassembly (2) and mounted in the first chamber (E1) and; - a driving rotor (6) mechanically coupled to a rotor of the electric motor (3) and mounted in a second chamber (E2), the driving rotor (6a) and the driven rotor (4a) being magnetically coupled.

Description

Fuel booster system for a fuel circuit

[0001] The present invention relates to the field of fuel feeding systems for a fuel circuit, in particular for an aircraft turbomachine.

[0002] 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.

[0003] The fuel circuit may traditionally comprise, in particular depending on the direction of fuel flow: one or more fuel storage tanks, a booster pump, a filter for retaining solid particles contained in the fuel, a mechanical pump, a valve for metering a mass flow of fuel and one or more injectors for spraying the mass flow into the combustion chamber.

[0004] If there are multiple fuel storage tanks, one or more transfer pumps are also used to transfer fuel between the fuel storage tanks.

[0005] 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.

[0006] The electric motor is said to be "immersed" in that the fuel circulates in the cavity of the motor in contact with the rotor and the stator.

[0007] The electric motor is typically an asynchronous motor connected directly to the aircraft's AC electrical network, with a voltage notably equal to 115VAC, acronym for "Volts Alternating Current" in English, or a permanent magnet synchronous motor controlled by an electronic control unit, also designated by the acronym "ECU" for "Electronic Command Unit (ECU)" in English, supplied with DC voltage typically 270VDC, acronym for "Volts Direct Current" in English, or with AC voltage of 115VAC.

[0008] 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 higher, or an alternating voltage of 230VAC or higher.

[0009] 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.

[0010] 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 an unpressurized area, the pressure of which can vary from approximately 1013 HPa on the ground to approximately 100 HPa at 16 km altitude in flight.

[0011] Low pressures are more likely to cause partial discharges according to Paschen's law. This is because lower pressure lowers the voltage at which partial discharges occur.

[0012] 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 breakdown. 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.

[0013] The body in which the motor is mounted is also flameproof. However, such barriers are likely to be insufficient to demonstrate that the risks of ignition remain extremely unlikely in the context of high voltage power supply, because these would not be independent of the degradation linked to partial discharges.

[0014] 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.

[0015] In the case of pumps with electric motors powered by low voltages, it is known from application BE1028023A1 to drive the motor by magnetic coupling and to offset it axially relative to the pump to make the size of the pump independent of that of the motor. A magnetic coupling is also taught by US20040109773A1 and US20150267704A1 in automotive and underwater fuel pumps respectively, which are not exposed to low pressures at high altitude. Neither of these architectures is exposed to the risk of occurrence of partial discharges and adapted to deal with it.

[0016] 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 certain 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”, fixed to the fuel tank 130 C. The housing 150 comprises a fuel inlet and outlet C equipped with closing valves. Once the cartridge 140 is installed, the fuel C circulates from the inlet to the outlet in the housing 150 via the cartridge 140.

[0017] During a maintenance operation, the shut-off valves are closed and the cartridge 140 is uninstalled. In practice, during such a maintenance operation, remnants of fuel C 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.

[0018] The invention thus also aims to reduce the risk of fuel projection during a maintenance operation on an electric motor fuel booster pump, in particular for an aircraft turbomachine. PRESENTATION OF THE INVENTION

[0019] The invention relates to a fuel boosting 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.

[0020] The invention is remarkable in that the fuel boosting system comprises:a driven rotor mechanically coupled to the rotating part of the hydraulic subassembly and mounted in the first enclosure, anda 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.

[0021] Such a fuel-boosting system ensures increased safety against the risk of partial discharge, particularly in the presence of high power supply voltages, such as 540VDC direct voltage or 230VAC alternating voltage.

[0022] 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.

[0023] In addition, the second enclosure is capable of housing at least the rotor and one stator of the electric motor.

[0024] Finally, the second enclosure is likely to be fixed against the first enclosure.

[0025] 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.

[0026] Additionally, the electric motor is advantageously confined in a fuel-free zone, reducing the risk of fuel vapors igniting from a spark.

[0027] 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.

[0028] According to one aspect of the invention, the fuel boosting 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.

[0029] 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 sealing manner to the pump body so as to form together 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 fixed in a sealing manner to the first enclosure so as to form the second enclosure.

[0030] 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.

[0031] According to other aspects of the invention, considered individually or in combination, the fuel booster system comprises:the hydraulic subassembly extends in a housing, the inner wall being sealed to the housing so as to together form the first enclosure, and / orthe electric motor extends in a cartridge, the cartridge being sealed to the first enclosure so as to form the second enclosure.

[0032] The attachment of the inner wall and cartridge to the housing forms a pressurized, fuel-free cavity for the electric motor. Using a cartridge makes it easier to remove during maintenance. In addition, the cartridge can form an additional explosion-proof barrier, in addition to the motor wall.

[0033] According to one aspect of the invention, the electric motor is electrically powered 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.

[0034] 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 saving linked to the integration of a magnetic coupling device, according to the invention.

[0035] According to one aspect of the invention, the second enclosure is explosion-proof, to meet aeronautical standards relating to electric motor-driven aircraft pumps in terms of safety. The second enclosure is in practice hermetic, which makes it explosion-proof.

[0036] 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.

[0037] 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.

[0038] The invention also relates to an aircraft turbomachine comprising a fuel circuit comprising a fuel boosting system as described previously.

[0039] The invention also relates to a method of using in flight an aircraft turbomachine as described previously, 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.

[0040] The invention also relates to a method for maintaining the electric motor of a fuel booster system as described previously, consisting of dismantling the second enclosure from the first enclosure. PRESENTATION OF FIGURES

[0041] The invention will be better understood on 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: La is a schematic representation in longitudinal section of a fuel booster pump in a turbomachine according to the prior art; La is a schematic representation in longitudinal section of a fuel booster system according to a first embodiment of the invention; La is a schematic representation in longitudinal section of a fuel booster system according to a second embodiment of the invention; La is a perspective representation of the fuel booster system of the;andLa, laand laare 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.;

[0042] 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

[0043] 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.

[0044] The fuel circuit may traditionally comprise, in particular depending on the direction of fuel flow: one or more fuel storage tanks, a booster 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 valve for metering a mass flow of fuel and / or one or more injectors for spraying the mass flow into the combustion chamber.

[0045] If there are multiple fuel storage tanks, one or more transfer pumps are also used to transfer fuel between the fuel storage tanks.

[0046] Figures 2 and 3 are schematic representations in longitudinal section of a fuel booster system according to a first form and a second embodiment of the invention.

[0047] More particularly, with reference to Figures 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.

[0048] The hydraulic subassembly 2 of the fuel booster system 1 comprises a rotating part 21, capable of driving 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 circulation of the fuel C.

[0049] The fuel booster system 1 according to the invention typically designates a booster pump or a transfer pump of the fuel circuit.

[0050] According to the invention, as illustrated in figures 2 and 3, the fuel booster 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.

[0051] 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 at least the rotor 31 and a stator 32 of the electric motor 3 are mounted. According to a particular embodiment of the invention, the second enclosure E2 is fixed against the first enclosure E1.

[0052] The fuel feeding system 1 according to the invention is a dry engine type architecture unlike the submerged engine architectures of the prior art.

[0053] 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.

[0054] 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 into the second enclosure E2 and the first enclosure E1 which form the air gap.

[0055] Thus, according to the invention, the fuel C is advantageously isolated from the high electrical voltages applied to the electric motor 3.

[0056] This is a perspective representation of the fuel booster system 1 of the.

[0057] 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.

[0058] The rotating part 21 is mounted in a pump body 20. The pump body 20 is fixed, being able to 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.

[0059] The hydraulic subassembly 2 is presented, 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.

[0060] 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.

[0061] In the example presented, the driving rotor 6 is integral in rotation 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 booster pump via the driving rotor 6 and the driven rotor 4, in particular magnetically coupled.

[0062] 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.

[0063] The electric motor 3 of the fuel booster system 1 may be in the example of figures 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.

[0064] Alternatively, the electric motor 3 may be in the form of an asynchronous motor suitable for direct connection to the electrical network.

[0065] The operation of the electric motor 3 is known and is not detailed further.

[0066] 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 flight, to maintain atmospheric pressure on the ground in the pressurized cavity, namely approximately 1013 HPa.

[0067] The electric motor 3 is thus protected from the low pressures observed at altitude, which can reach around 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] In the first embodiment illustrated in Figures 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.

[0078] 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 furthermore 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.

[0079] 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 leaking and splashing, according to the fuel pumps of the prior art, no longer exists thanks to the presence of the internal wall 5.

[0080] Illustrates a second embodiment of the invention in which the fuel supply system 1 further comprises a housing 11, also referred to as a canister, and a cartridge 10.

[0081] 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.

[0082] 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 sub-assembly 2.

[0083] 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.

[0084] The cartridge 10 is fixed to the housing 11, in particular as shown in the example of the, along the longitudinal axis X. The cartridge 10 may comprise aluminum.

[0085] In the second embodiment illustrated in , the feeding system 1 comprises, in a similar manner 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, radially inwardly relative to the housing 11.

[0086] 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.

[0087] Similar to the first embodiment, the inner wall 5 is common 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 4 magnetically coupled.

[0088] As for 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,

[0089] Such fixing members 7, 8 are, for example, screws, preferably supplemented by a sealing gasket, for example made of fluorosilicone. The fixing members 7, 8 are furthermore 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.

[0090] 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.

[0091] The internal wall 5 may comprise a non-magnetic material, in particular polyetheretherketone.

[0092] Figures 5, 6 and 7 are exploded perspective representations 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.

[0093] In the configuration of the, the driven rotor 4 extends radially inwardly relative to the driving rotor 6 along the longitudinal axis X.

[0094] In the configuration of the, the driving rotor 6 extends radially inwardly relative to the driven rotor 4 along the longitudinal axis X.

[0095] For the configurations of Figures 5 and 6, the magnetic coupling is radial. The inner wall 5 preferably comprises a bell shape.

[0096] 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 a bell shape, as shown in the.

[0097] The configurations of Figures 5, 6 and 7 are each compatible with the two embodiments of Figures 2 to 4.

[0098] With reference to the, a method of using a fuel booster system 1 according to any one of the embodiments described comprises at least: a powering 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 driving step, during which the rotor 31 of the electric motor 3 is magnetically driven in rotation; a driving rotor driving 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 in rotation in the first enclosure E1 from the rotation of the driving rotor 6 in the second enclosure E2.

[0099] 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 flow of fuel C.

Claims

Fuel boosting system (1) for a fuel circuit (C) 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), andan electric motor (3), capable of driving the hydraulic subassembly (2) and supplied with high direct or alternating voltage,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, the second enclosure (E2) being sealed against the fuel (C) and defining a pressurized cavity. Fuel feeding system (1) according to claim 1, 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 booster system (1) according to claim 2, wherein:the hydraulic subassembly (2) comprises a pump body (20) surrounding the rotating part (21), the inner wall (5) being fixed in a sealed manner to the pump body (20) so as to form the first enclosure (E1), and / orthe 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 booster system (1) according to claim 2, 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 / orthe electric motor (3) extends in 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 booster system (1) according to any one of the preceding claims, wherein the electric motor (3) is electrically supplied with a direct voltage greater than 320VDC or an alternating voltage greater than 203VAC. Fuel booster 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 7, wherein 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 for using an aircraft turbomachine in flight according to claim 9, in which the rotor (31) of the electric motor (3) of the fuel boosting 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.

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