Aircraft engine fuel supply circuit

Abstract

The invention relates to a fuel supply circuit for an aircraft engine, comprising a centrifugal pump mechanically coupled to a drive shaft (18) transmitting mechanical power. The circuit further comprises at least one electromagnetic pump (100) having at least one stator (110) defining an annular internal volume, in which there is a rotor (120) capable of driving a fluid, a plurality of magnets (130) annularly distributed around the rotor (120), and at least a plurality of coils (140) annularly distributed inside the stator (110) opposite the magnets (130). The rotor (120) is connected to the drive shaft (18) via a one-way clutch element (150).

Description

Technical Field

[0001] The present invention relates to the field of turbomachines of the type comprising a rotating body including a motor shaft transmitting mechanical power.

[0002] The invention is applicable to any type of turbomachine, in particular turbomachines used in aircraft, such as turbojets, turboprops and unducted fan turbines, also known as “open rotor” turbines. Background Art

[0003] Conventional turbomachines, in a known manner, comprise one or more rotating bodies. Each rotating body includes a compressor, a turbine, and a shaft connecting the turbine to the compressor to drive its rotation. A portion of the power generated by the turbine is used to drive various accessories (or spare parts) required to operate the turbojet engine or aircraft, such as lubrication pumps or fuel pumps.

[0004] To this end, turbines typically include a gearbox (accessory gearbox) that connects the engine shaft to these pumps. When the engine shaft is driven in rotation, the accessory gearbox transmits the rotational motion to the various accessories. In other words, the mechanical force generated by the engine shaft is transmitted to the pumps via the accessory gearbox.

[0005] However, this technical solution does have drawbacks. Specifically, the speed of the pump or pumps depends on the engine shaft speed, making it impossible to control the pump or pumps independently of the engine rating. This can be problematic, for example, when it comes to the fuel supply circuit of a turbine. Specifically, the flow rate of the pump or pumps present in the supply circuit depends on the engine rating, which doesn't always make it possible to optimize the fuel flow rate to the engine requirements, particularly during turbine startup. Summary of the Invention

[0006] The object of the present invention is in particular to provide a turbomachine which does not have the above-mentioned disadvantages.

[0007] This object is achieved thanks to a fuel supply circuit for an aircraft engine, said circuit comprising at least one centrifugal pump mechanically coupled to an engine shaft transmitting mechanical power, characterised in that said circuit further comprises at least one electromagnetic pump comprising at least one stator delimiting an annular internal volume, in which there is a rotor capable of driving a fluid, several magnets annularly distributed inside the rotor, and at least several coils annularly distributed inside the stator facing the magnets, and wherein the rotor is connected to the engine shaft via a one-way clutch element.

[0008] In the fuel supply circuit of the present invention, the selective coupling of an electromagnetic pump with a centrifugal pump provides new functionality while maintaining a high level of reliability. Since the electromagnetic pump is fueled by an electrical energy source independent of the mechanical energy supplied to the engine shaft during turbine startup, the electromagnetic pump can be advantageously used to prime the fuel circuit (priming) before engine startup. The fuel flow rate can also be regulated by the electromagnetic pump, independently of the engine rating, allowing control of the flow rate to closely match the fuel requirements while limiting fuel recirculation.

[0009] According to a particular feature of the circuit of the invention, the rotor comprises a wheel equipped with blades, the magnets being fixed at the level of the radially outer ends of the blades of the wheel, the coils of the coils facing the magnets in the radial direction.

[0010] According to another particular feature of the circuit of the invention, the rotor comprises an internal pinion interacting with an outer ring having internal teeth, the magnets of the several magnets being fixed at the level of the outer periphery of the outer ring, the coils of the several coils facing the magnets of the several magnets in the radial direction.

[0011] By placing several permanent magnets and several coils face to face in the radial direction, the axial volume of the pump is greatly optimized, thus obtaining a very compact pump.

[0012] According to another particular feature of the circuit of the invention, the rotor comprises a wheel with blades, the magnets of which are fixed at the level of the outer periphery of the wheel, the coils of which are facing the magnets in the axial direction.

[0013] According to another particular feature of the circuit of the invention, the rotor comprises an internal pinion interacting with an outer ring with internal teeth, the magnets of which are fixed at the level of the outer periphery of the outer ring, the coils of which face the magnets in the axial direction.

[0014] According to another particular feature of the circuit of the invention, the rotor comprises an internal pinion interacting with an outer ring having internal teeth, the magnets of the several magnets being fixed to the internal pinion and the coils of the several coils facing the magnets in the axial direction.

[0015] By placing several permanent magnets and several coils face to face in the axial direction, the radial volume of the pump is greatly optimized, thereby obtaining a very compact pump.

[0016] According to another particular feature of the circuit of the present invention, each electromagnetic pump includes a first and a second plurality of coils, respectively, located on either side of the wheel, outer ring, or inner gear, with these coils facing the magnets in the axial direction. These two sets of coils ensure redundancy in the event of failure or malfunction of one set of coils. This redundancy also serves to double the electromagnetic power experienced by the permanent magnets.

[0017] According to another particular feature of the circuit according to the present invention, the plurality of magnets are arranged at an angle in a Halbach configuration. This particular arrangement increases the magnetic field on the outside of the rotor while substantially suppressing the magnetic field on the inside. This reduces magnetic field losses, which improves rotor control via the coils.

[0018] According to another particular feature of the circuit of the invention, each electromagnetic pump is capable of generating an electric current. This allows the electromagnetic pump to store electrical energy when it is not used for pumping.

[0019] Another subject of the invention is an aircraft engine comprising a fuel supply circuit according to the invention.

[0020] Another subject of the invention is the fueling of an aircraft engine using a fuel supply circuit according to the invention, said circuit being connected to a fuel tank without any priming pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic illustration of the fuel supply of a gas turbine aircraft engine,

[0022] FIG2 is a schematic exploded perspective view of an electromagnetic pump according to an embodiment of the present invention,

[0023] FIG3 is a schematic perspective view of a portion of the electromagnetic pump of FIG2 ,

[0024] FIG4 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the present invention,

[0025] FIG5 is a schematic perspective view of a portion of the electromagnetic pump of FIG4 ,

[0026] FIG6 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the present invention,

[0027] FIG7 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the present invention,

[0028] FIG8 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the present invention,

[0029] FIG9 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the present invention,

[0030] FIG. 10 shows an annular arrangement of permanent magnets as a Halbach structure. DETAILED DESCRIPTION

[0031] The invention is generally applicable to any turbomachine comprising a rotating body including an engine shaft transmitting mechanical power and at least one centrifugal pump mechanically coupled to the engine shaft.

[0032] FIG1 shows an example of a fuel supply circuit 1 , which is described in the context of an application in a turbomachine equivalent to a gas turbine aircraft engine.

[0033] A fuel supply circuit 1 connects an aircraft's fuel tank 10 to a turbine's combustion chamber 21. Here, fuel supply circuit 1 consists of a low-pressure pump 11 connected to tank 10, a filter 12, a high-pressure pump 13, a metering device 14, and an oil / fuel heat exchanger 15 connected to combustion chamber 21. The turbine specifically includes an accessory gearbox 17, to which is connected an engine shaft 18 for transmitting mechanical power. Low-pressure pump 11 and high-pressure pump 13 are centrifugal pumps mechanically coupled to the engine shaft.

[0034] According to the present invention, an electromagnetic pump 20 is also more closely associated with the low-pressure centrifugal pump 11. The electromagnetic pump 20 can be, for example, a liquid ring type, a side channel type, a regenerative type, or a cycloid type, independently controlled by a digital computer 16 integrated into the turbine control unit. As described in detail below, the rotor of the electromagnetic pump 20 is connected to the engine shaft 18 via a one-way clutch element.

[0035] A low-pressure centrifugal pump 11 and an electromagnetic pump 20 are both connected to the fuel supply circuit. More specifically, the inlets of pumps 11 and 20 are connected to the fuel tank 10, while the outlets of pumps 11 and 20 are connected to the filter 12. Fuel can be supplied to the turbine via the low-pressure centrifugal pump 11, the electromagnetic pump 20, or both pumps 11 and 20.

[0036] Various embodiments of electromagnetic pumps that may be used in the present invention, such as the electromagnetic pump 20 described above, will be described below.

[0037] FIG2 shows an electromagnetic pump 100 according to one embodiment of the present invention. In the example described herein, the electromagnetic pump 100 is a liquid ring pump comprising a stationary pump body or stator 110 consisting of a half-shell 111 and a half-shell 112. The half-shells 111 and 112 each comprise a solid cylindrical center member 1110 and 1120, respectively, equipped with suction / discharge ports 1111 and 1121, respectively, and a circular outer wall 1112 and 1122, respectively, extending concentrically around the center members 1110 and 1120, respectively. An annular housing 1113 and 1123 are defined between the center members 1110 and 1120, respectively, and between the outer walls 1112 and 1122, respectively.

[0038] The electromagnetic pump 100 further comprises an impeller or rotor 120, which comprises an impeller or rotor 120 provided with a plurality of impellers extending in a radial direction D from the impeller. R The rotor 121 has several blades 122 extending therefrom. The impeller 120 includes a bearing 124. Openings 1114 and 1124 are present in the half-shell 111 and half-shell 112, respectively. The bearing 1124 is used to interact with the flywheel 150, thereby forming a one-way clutch element connecting the engine shaft 18 to the impeller 120 of the electromagnetic pump 100. The openings 1114 and 1124 allow the engine shaft 18 to pass through.

[0039] In a liquid ring pump, a flywheel 150 is positioned eccentrically on the impeller 120, for example, via a gasket (not shown in FIG. 2 ), creating a variation in the inter-blade (or inter-vane) volume that allows the pumped fluid to be drawn in, for example, through port 1111, and then discharged under pressure, for example, through port 1121. Pump 100 can also be a side-channel pump, also known as a regenerative pump. In this case, a side channel 1125 (shown in dashed lines in FIG. 2 ), located on half-shell 112, extends between ports 1111 and 1121. The variation in the inter-blade (or inter-vane) volume variation, associated with the velocity field (vortex) present in side channel 1125, allows the fluid to be drawn in, for example, through port 1111, and then discharged under pressure, for example, through port 1121. Electromagnetic pump 100 further includes a plurality of permanent magnets 130 annularly distributed on the impeller or rotor 120 and a plurality of coils 140 annularly distributed inside the stationary pump body or stator 110. More specifically, in the example described here, the permanent magnet 130 is fixed to the radially outer end of the blade 122, while the coil 140 is fixed to the inner surface of the support ring 141, and the assembly of the coil and the support ring is located in the annular shell 1113 of the half shell 111 and in the annular shell 1123 of the half shell 112.

[0040] Once all components of the pump 100 are assembled, the permanent magnet 130 will be arranged in the radial direction D shown in FIG. 3 . R It is positioned face to face with the coil 140. Control of the electromagnetic pump 100 (torque and speed) is accomplished by controlling the current circulating through the coil.

[0041] By attaching the permanent magnet 130 directly to the impeller 120 , a part of the drive device of the pump is directly integrated into the moving element, which makes it possible to obtain a high level of integration of the drive device and thus reduce the overall volume of the pump.

[0042] Furthermore, by placing several permanent magnets and several coils facing each other in the radial direction, the radial volume of the pump is greatly optimized. Thus, a very compact pump is obtained, which can be driven independently of the engine rating of the turbine to which it is associated.

[0043] FIG4 illustrates an electromagnetic pump 200 according to another embodiment of the present invention. In this embodiment, the pump 200 is a gerotor pump comprising a stationary pump body or stator 210 comprised of a housing 211 and a flange 212. The housing 211 comprises an inner housing 2113 defined by an outer wall 2112. The flange 212 comprises an intake port 2120 and an exhaust port 2121.

[0044] The electromagnetic pump 200 also includes a rotor 220, which includes an inner pinion 221 and an outer ring 222. The inner pinion 221 includes an outer toothing consisting of six teeth 2210, while the outer ring 222 includes an inner toothing consisting of seven teeth 2220. The inner pinion 221 includes a bearing 224. Openings 2114 and 2124 are located in the housing 211 and the flange 212, respectively. The bearing 224 is configured to interact with the flywheel 250, forming a one-way clutch element that connects the engine shaft 18 to the rotor 220 of the electromagnetic pump 200. The openings 2114 and 2124 allow the engine shaft 18 to pass through.

[0045] In a cycloid pump, fluid is drawn from port 2120 and discharged through port 2121 by pockets formed between teeth 2210 and 2220 of inner pinion 221 and outer race 222 , respectively, as they rotate.

[0046] The electromagnetic pump 200 further includes a plurality of permanent magnets 230 annularly distributed on the outer periphery of the outer ring 222 and a plurality of coils 240 annularly distributed inside the fixed pump body or stator 210. More specifically, the coils 240 are fixed to the inner surface of a support ring 241, and the assembly of the coils and the support ring is located in an inner housing 2113 of the housing 211.

[0047] Once all components of the pump 200 are assembled, the permanent magnet 230 will be aligned in the radial direction D shown in FIG. 5 . R It is placed face to face with the coil 240. Control of the electromagnetic pump 200 (torque and speed) is generated by circulating the current through the coil.

[0048] By attaching the permanent magnet 230 directly to the inner pinion 221 , a part of the pump drive is integrated directly inside the moving element, which makes it possible to obtain a high level of integration of the drive and thus reduce the volume of the pump.

[0049] Furthermore, by placing several permanent magnets and several coils facing each other in the radial direction, the radial volume of the pump is greatly optimized. Thus, a very compact pump is obtained which can be controlled independently of the engine rating of the turbine to which it is associated.

[0050] FIG6 shows an electromagnetic pump 300 according to another embodiment of the present invention. In the example described herein, the electromagnetic pump 300 is a liquid ring pump comprising a stationary pump body or stator 310 consisting of a housing 311 and a flange 312. The housing 311 comprises a solid cylindrical central part 3110 equipped with suction / discharge ports 3111 and a circular outer wall 3112 extending concentrically around the central part 3110, with an annular housing 3113 defined between the central part 1110 and the outer wall 3112. The flange 312 comprises a discharge / suction pump 3120.

[0051] The electromagnetic pump 300 further comprises an impeller or rotor 320, which comprises a plurality of impellers or rotors 320, each of which is provided with a plurality of impellers or rotors 320 extending radially from the impeller 320 to the rotor 320. R The impeller 321 of the plurality of blades 322 is extended, and the ring 323 is located at the level of the outer periphery of the impeller. In the example described here, the ring 323 is attached to the radially outer ends of the blades 322.

[0052] Impeller 320 includes bearings 324. Openings 3114 and 3124 are located in half-shell 311 and half-shell 312, respectively. Bearing 324 interacts with flywheel 350, forming a one-way clutch element connecting engine shaft 18 to impeller 320 of electromagnetic pump 300. Openings 3114 and 3124 allow engine shaft 18 to pass through. Bearing 324 is eccentrically positioned on impeller 320, creating inter-blade (or inter-blade) volume changes that are used to draw in pumped fluid, for example, through port 3111, and then discharge it under pressure, for example, through port 3120. Pump 300 can also be a side-channel pump, also known as a regenerative pump. In this case, a side channel 3125 (shown in dashed lines in FIG. 6 ) present on flange 312 extends between ports 3111 and 3120. The inter-blade (or inter-blade) volume changes associated with the velocity fields (eddies) present in the side channels 3125 can, for example, draw in fluid through port 3111 and then discharge it under pressure, for example, through port 3120. The electromagnetic pump 300 further includes a plurality of permanent magnets 330 annularly distributed on the impeller or rotor 320 and a plurality of coils 340 annularly distributed inside the stationary pump body or stator 310. More specifically, in the example described here, the permanent magnets 330 are fixed in a housing 3230 present in a ring 323, while the coils 340 are fixed in an annular housing 3113 present in the casing 311.

[0053] Once all components of the pump 300 are assembled, the coil 340 is arranged in the axial direction D A It is positioned face to face with the permanent magnet 330. The electromagnetic pump 300 is controlled (torque and speed) by controlling the current flowing through the coil.

[0054] By attaching the permanent magnet 330 directly to the impeller 320 , a part of the pump drive is integrated directly into the moving element, which makes it possible to obtain a high level of integration of the drive and thus reduce the overall volume of the pump.

[0055] Furthermore, by placing several permanent magnets and several coils facing each other in the axial direction, the radial volume of the pump is significantly optimized. This results in a very compact pump that can be controlled independently of the engine rating of the turbine to which it is associated.

[0056] FIG7 shows another embodiment of an electromagnetic pump 400, which differs from the electromagnetic pump 300 described in conjunction with FIG6 in that it includes a double coil. More specifically, as for the pump 300, the pump 400 includes a plurality of coils extending radially from the impeller in the direction D. R An impeller or rotor 420 extends from a plurality of blades 422 , with a ring 423 attached to the radially outer ends of the blades 422 .

[0057] The electromagnetic pump 400 further comprises a stationary pump body or stator 410 comprised of a first housing 411 and a second housing 412. The housings 411 and 412 each comprise a solid cylindrical central member 4110, 4120, respectively, provided with suction / discharge ports 4111, 4121 and circular outer walls 4112, 4122 extending concentrically around the central members 4110, 4120. A first annular housing 4113 is defined in the first housing 411 between the central member 4110 and the outer wall 4112. A second annular housing 4123 is defined in the second housing 412 between the central member 4120 and the outer wall 4122.

[0058] The electromagnetic pump 400 further includes a plurality of permanent magnets 430 annularly fixed in a housing 4230 present in the ring 423, and first and second plurality of coils 440 and 445. The first plurality of coils 440 are annularly distributed in the first annular housing 4113, while the second plurality of coils 445 are annularly distributed in the second annular housing 4123.

[0059] The impeller 420 includes a bearing 424. Openings 4114 and 4124 are located on the half-shell 411 and half-shell 412, respectively. The bearing 424 is used to interact with the flywheel 450, thereby forming a one-way clutch element that connects the engine shaft 18 to the impeller 420 of the electromagnetic pump 400. The openings 4114 and 4124 allow the engine shaft 18 to pass through.

[0060] Once the pump 400 is assembled, the first and second plurality of coils 440 and 445 are located on either side of the impeller 420 and are arranged in the axial direction D A Face to face with the magnet.

[0061] In addition to the integration and compactness advantages already described above for pump 300, electromagnetic pump 400 includes two sets of coils, which ensure redundancy in the event of failure or malfunction of one set of coils, with each set of coils having its own connection to the control system. The redundancy of the coils can also be used to double the electromagnetic pump power received by the permanent magnet. It will also be noted that, again in order to optimize the overall size of the pump, redundancy is provided only for these coils, and as close to the permanent magnet as possible.

[0062] Pump 400 may also be a side channel pump as previously explained with respect to pump 300 , still further referred to as a regeneration pump.

[0063] FIG8 shows an electromagnetic pump 500 according to another embodiment of the present invention. In this embodiment, the pump 500 is a gerotor pump comprising a stationary pump body or stator 510 comprised of a housing 511 and a flange 512. The housing 511 comprises a solid cylindrical center member 5110 and a circular outer wall 5112 extending concentrically around the center member 5110, with an annular housing 5113 defined between the center member 5110 and the outer wall 5112. The flange 512 comprises a suction port 5120 and a discharge port 5121.

[0064] The electromagnetic pump 500 further includes a rotor 520, which includes an inner pinion 521 and a plurality of inner pinions 522 along a radial direction D. R An outer ring 522 is located around the inner pinion 521. The inner pinion includes an outer toothing consisting of six teeth 5210, while the outer ring 522 includes an inner toothing consisting of seven teeth 5220.

[0065] The inner pinion 521 includes a bearing 524. Openings 5114 and 5124 are located on the housing 511 and the flange 512. The bearing 524 is used to interact with the flywheel 550, thereby forming a one-way clutch element that connects the engine shaft 18 to the rotor 520 of the electromagnetic pump 500, and the openings 5114 and 5124 allow the engine shaft 18 to pass through.

[0066] In a cycloid pump, fluid is drawn from port 5120 and discharged through port 5121 by pockets formed between teeth 5210 and 5220 of inner pinion 521 and outer race 522 , respectively, as they rotate.

[0067] The electromagnetic pump 500 further includes a plurality of permanent magnets 530 annularly distributed on the outer periphery of the outer ring 522 and a plurality of coils 540 annularly distributed inside the fixed pump body or stator 510. More specifically, in the example described here, the permanent magnets 530 are fixed in a housing 5221 present in the outer ring 522, while the coils 540 are fixed in an annular housing 5113 present in the housing 511.

[0068] Once all components of the pump 500 are assembled, the coil 540 is arranged in the axial direction D A It is positioned face to face with the permanent magnet 530. The electromagnetic pump 500 is controlled (torque and speed) by controlling the current flowing through the coil.

[0069] By attaching the permanent magnets 530 directly to the outer ring 522 , a part of the pump drive is directly integrated into the moving element, which allows a high level of integration of the drive and thus a reduction in the overall volume of the pump.

[0070] Furthermore, by placing several permanent magnets and several coils facing each other in the axial direction, the radial volume of the pump is greatly optimized. Thus, a very compact pump is obtained, which can be driven independently of the engine rating of the turbine to which it is associated.

[0071] The electromagnetic pump 500 can also be provided with a double coil as described for the pump 400 of FIG 7 . In this case, the pump comprises a second number of coils distributed annularly in a housing present on the flange 512 .

[0072] FIG9 shows another embodiment of an electromagnetic pump 600, which differs from the electromagnetic pump 500 described in conjunction with FIG8 in that the permanent magnet is fixed to the internal pinion. More specifically, as with pump 500, the cycloid pump 600 includes a stationary pump body or stator 610 comprised of a housing 611 and a flange 612. The housing 611 includes an annular housing 6113. The flange 612 includes an inlet port 6120 and an outlet port 6121.

[0073] The electromagnetic pump 600 further includes a rotor 620, which includes an inner pinion 621 and a plurality of inner pinions 622 arranged along a radial direction D. R The outer ring 622 is located around the inner pinion 621. The inner pinion has an outer toothing consisting of six teeth 6210, while the outer ring 622 has an inner toothing consisting of seven teeth 6220.

[0074] The inner pinion 621 includes a bearing 624. Openings 6114 and 6124 are located on the housing 611 and the flange 612, respectively. The bearing 624 is used to interact with the flywheel 150, thereby forming a one-way clutch element that connects the engine shaft 18 to the rotor 620 of the electromagnetic pump 600, and the openings 6114 and 6124 allow the engine shaft 18 to pass through.

[0075] The electromagnetic pump 600 further includes a plurality of permanent magnets 630 annularly fixed in the inner pinion 621 around the bearing 624 , and a plurality of coils 640 fixed in an annular housing 6113 present in the housing 611 .

[0076] Once all components of the pump 600 are assembled, the coil 640 is arranged in the axial direction D AIt is positioned face to face with the permanent magnet 630. The electromagnetic pump 600 is controlled (torque and speed) by controlling the current flowing through the coil.

[0077] By attaching the permanent magnet 630 directly to the inner pinion 621 , a part of the pump drive is directly integrated into the moving element, which makes it possible to obtain a high level of integration of the drive and thus reduce the overall volume of the pump.

[0078] Furthermore, by placing several permanent magnets and several coils facing each other in the axial direction, the radial volume of the pump is greatly optimized. Thus, a very compact pump is obtained, which can be driven independently of the engine rating of the turbine to which it is associated.

[0079] In the same manner as with the previously described pumps, the electromagnetic pump 600 may be equipped with a double coil, ie comprising first and second coils respectively located on either side of the inner pinion, these coils facing the magnet in the axial direction.

[0080] According to an additional feature of the present invention, the permanent magnets located at the radially outer ends of the blades of the impeller for the embodiments described above in conjunction with Figures 2, 3, 6 and 7, or located at the outer ring for the embodiments described above in conjunction with Figures 4, 5 and 8, or on the inner pinion for the embodiment described above with respect to Figure 9, can be arranged as a Halbach structure. Figure 10 shows an example of a permanent magnet arrangement as a Halbach structure. In this example, the permanent magnets 30 are distributed annularly in the rotor as previously described, while reversing the polarity of the magnets in the radial direction and in the circumferential direction as indicated by the arrows shown in Figure 10. This particular arrangement can increase the magnetic field 40 on the outside of the rotor while substantially suppressing the magnetic field on the inside of the rotor. The magnetic field losses are thereby reduced, which improves the control of the rotor by the coils.

[0081] A one-way clutch element, such as the flywheel described above, can selectively couple the rotor of the electromagnetic pump to the engine shaft used to control the centrifugal pump. Thus, the electromagnetic pump can be used in several operating modes in the turbomachine.

[0082] The first operating mode corresponds to priming the turbine's fuel supply circuit while the engine is shut down. During this phase, after fully or partially draining the supply circuit between the turbine's fuel tank and combustion chamber, the fuel supply circuit may contain air. The presence of air significantly reduces the centrifugal pump's intake capacity, which can even prevent the engine from starting. One known solution from the prior art involves equipping the fuel tank with a priming pump, a so-called "feed pump," which can fill the supply circuit between the fuel tank and the engine. However, installing a feed pump in the fuel tank is complex and increases the mass of the assembly, even though the pump is only used for possible priming before starting the engine.

[0083] According to the invention, priming of the fuel supply circuit is carried out by commanding the electromagnetic pump from an independent electrical energy source, in order to fill the fuel supply circuit before starting the engine. In this first operating mode, the so-called "priming mode," the rotor of the electromagnetic pump rotates freely about the engine shaft, which is immobilized due to the presence of the one-way clutch element interposed between the rotor and the engine shaft.

[0084] A second operating mode, the so-called "boost mode," is implemented when the engine is ignited and the centrifugal pump is driven by the engine shaft. In this mode, the rotor of the electromagnetic pump is driven by an independent electrical energy source at a speed higher than the engine shaft speed, which provides additional pumping capacity to the centrifugal pump. A one-way clutch element allows the rotor of the electromagnetic pump to rotate at a speed higher than the engine shaft speed.

[0085] A third operating mode, the so-called "generator mode," is implemented when the engine is ignited. The centrifugal pump is driven by the engine shaft. The electromagnetic pump is not powered by an electrical energy source, but its rotor is rotationally driven by the engine shaft due to the presence of a one-way clutch element interposed between the rotor and the engine shaft. In this mode, the electromagnetic pump is converted into a generator, generating current that can be drawn from the pump's coils and stored in a battery for later use, for example, to operate the electromagnetic pump in the first and second operating modes.

Claims

1. A fuel supply circuit for an aircraft engine connecting a fuel tank to a combustion chamber of a turbine, comprising at least one low-pressure centrifugal pump mechanically connected to the engine shaft, wherein: It also includes at least one electromagnetic pump, which includes at least one stator defining an annular internal volume, in which there is a rotor capable of driving a fluid, a plurality of magnets distributed annularly on the rotor, and at least a plurality of coils distributed annularly on the inner side of the stator facing the magnets (130), the rotor being connected to the engine shaft via a one-way clutch element, the rotor including an inner pinion interacting with an outer ring having inner teeth, the magnets of the plurality of magnets being fixed on the inner pinion, and the coils of the plurality of coils facing the magnets in the axial direction.

2. The circuit according to claim 1, wherein: Each electromagnetic pump includes first and second coils respectively located on either side of the pinion gear, the coils of the first and second coils facing the magnet in the axial direction.

3. The circuit according to claim 1, wherein: Every solenoid pump is capable of generating an electric current.

4. An aircraft engine comprising a fuel supply circuit according to claim 1.

5. Use of a fuel supply circuit according to claim 1 for the fuel supply of an aircraft engine, said circuit being connected to a fuel tank without any priming pump.

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