FUEL SUPPLY CIRCUIT OF AN AIRCRAFT ENGINE

Abstract

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

Description

[0001] Description

[0002] Title of the invention: Aircraft engine fuel supply circuit

[0003] Technical Field

[0004] The present invention relates to the field of turbomachinery of the type comprising a rotating body including a drive shaft delivering mechanical power. The invention applies to all types of turbomachinery, in particular those used in aircraft such as turbojets, turboprops, and open-fan turbomachinery, also known by the English term "open rotor".

[0005] Previous technique

[0006] A conventional turbomachine typically comprises one or more rotating components. Each rotating component includes a compressor, a turbine, and a drive shaft connecting the turbine to the compressor to rotate the compressor. Part of the power generated by the turbomachine is used to drive various accessories (or auxiliary machines) necessary for the operation of the turbojet engine or aircraft, such as a lubrication pump or a fuel pump.

[0007] For this purpose, the turbomachine typically includes an accessory gearbox connecting the drive shaft to the pumps. When the drive shaft is rotated, the accessory gearbox transmits the rotational motion to the various accessories. In other words, the mechanical energy produced by the drive shaft is transmitted to the pumps via the accessory gearbox.

[0008] This technical solution, however, has drawbacks. The rotational speed of the pump(s) is dependent on the rotational speed of the engine shaft, meaning the pump(s) cannot be controlled independently of the engine speed. This can be problematic, for example, in the turbomachine's fuel supply circuit. The flow rate of the pump(s) in the supply circuit is dependent on the engine speed, which doesn't always allow for optimizing the fuel flow to meet the engine's needs, particularly during turbomachine startup.

[0009] Description of the invention

[0010] The invention aims in particular to provide a turbomachine that does not have the aforementioned disadvantages.

[0011] This goal is achieved through an aircraft engine fuel supply circuit comprising at least one centrifugal pump mechanically coupled to a drive shaft delivering mechanical power, characterized in that it further comprises at least one electromagnetic pump comprising at least one stator delimiting an annular internal volume in which is present a rotor capable of driving a fluid, a plurality of magnets distributed annularly on the rotor and at least one plurality of coils distributed annularly inside the stator opposite the magnets and in that the rotor is connected to the drive shaft by a unidirectional clutch element.

[0012] The selective coupling of an electromagnetic pump with a centrifugal pump in the fuel supply circuit of the invention provides new functionalities while maintaining a high level of reliability. Since the electromagnetic pump is powered by an electrical energy source independent of the mechanical energy supplied to the engine shaft when the turbomachine is started, it can advantageously be used to prime the fuel circuit before engine start. The fuel flow rate can also be adjusted by the electromagnetic pump, independently of engine speed, allowing for precise control of the flow rate to closely match fuel demand while minimizing fuel recirculation.

[0013] According to a particular feature of the circuit of the invention, the rotor comprises a wheel equipped with a plurality of blades, the magnets of the plurality of magnets being held at the radially external ends of the wheel blades, the coils of the plurality of coils being opposite the magnets of the plurality of magnets in a radial direction. According to another particular feature of the circuit of the invention, the rotor comprises an inner pinion cooperating with an outer ring gear with internal teeth, the magnets of the plurality of magnets being held at the outer periphery of the outer ring gear, the coils of the plurality of coils being opposite the magnets of the plurality of magnets in a radial direction.

[0014] By placing the plurality of permanent magnets and the plurality of coils opposite each other along the radial direction, the axial footprint of the pump is greatly optimized. This results in a very compact pump.

[0015] According to another particular feature of the circuit of the invention, the rotor comprises a wheel equipped with a plurality of blades, the magnets of the plurality of magnets being held at the level of the outer periphery of the wheel, the coils of the plurality of coils being opposite the magnets in an axial direction.

[0016] According to another particular feature of the circuit of the invention, the rotor comprises an inner pinion cooperating with an outer ring with internal teeth, the magnets of the plurality of magnets being held at the level of the outer periphery of the outer ring, the coils of the plurality of coils being opposite the magnets in an axial direction.

[0017] According to another particular feature of the circuit of the invention, the rotor comprises an inner pinion cooperating with an outer ring with internal teeth, the magnets of the plurality of magnets being held on the inner pinion, the coils of the plurality of coils being opposite the magnets in an axial direction.

[0018] By placing the plurality of permanent magnets and the plurality of coils opposite each other along the axial direction, the radial dimensions of the pump are greatly optimized. This results in a very compact pump.

[0019] According to yet another particular feature of the circuit of the invention, each electromagnetic pump comprises first and second pluralityes of coils located respectively on one side and the other side of the outer wheel, ring gear, or inner pinion, the coils of the first and second pluralityes of coils being aligned with the magnets along the axial direction. Two pluralityes of coils provide redundancy in the event of a failure or malfunction of one plurality of coils. The redundancy of the plurality of coils can also be used to double the strength of the electromagnetic fields to which the permanent magnets are subjected.

[0020] According to another particular feature of the circuit of the invention, the magnets of the plurality of magnets are arranged in an annular configuration according to a Halbach structure. This particular arrangement increases the magnetic field on the outer side of the rotor while the magnetic field on the inner side of the rotor is substantially canceled. This reduces the loss of the magnetic field, thereby improving the control of the rotor by the coils.

[0021] According to another particular feature of the circuit of the invention, each electromagnetic pump is capable of generating an electric current. This makes it possible to produce and store electrical energy when the electromagnetic pump is not used for pumping.

[0022] The invention also relates to an aircraft engine comprising a fuel supply circuit according to the invention. The invention further relates to the use of the fuel supply circuit according to the invention for supplying fuel to an aircraft engine, said circuit being connected to a fuel tank without a priming pump.

[0023] Brief description of the drawings [Fig. 1] Figure 1 is a schematic representation of a fuel supply circuit for a gas turbine aircraft engine,

[0024] [Fig. 2] Figure 2 is a schematic exploded perspective view of an electromagnetic pump according to one embodiment of the invention,

[0025] [Fig. 3] Figure 3 is a schematic perspective view of part of the electromagnetic pump shown in Figure 2.

[0026] [Fig. 4] Figure 4 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the invention,

[0027] [Fig. 5] Figure 5 is a schematic perspective view of a portion of the electromagnetic pump of Figure 4, [Fig. 6] Figure 6 is an exploded schematic perspective view of an electromagnetic pump according to another embodiment of the invention,

[0028] [Fig. 7] Figure 7 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the invention,

[0029] [Fig. 8] Figure 8 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the invention,

[0030] [Fig. 9] Figure 9 is a schematic exploded perspective view of an electromagnetic pump according to another embodiment of the invention,

[0031] [Fig. 10] Figure 10 represents an annular arrangement of permanent magnets following a Halbach structure.

[0032] Description of the implementation methods

[0033] The invention applies generally to any turbomachine comprising a rotating body including a drive shaft delivering mechanical power and at least one centrifugal pump mechanically coupled with the drive shaft.

[0034] Figure 1 illustrates an example of a fuel supply circuit 1 which is described in the context of an application to a turbomachine corresponding to a gas turbine aircraft engine.

[0035] The fuel supply circuit 1 connects a fuel tank 10 of an aircraft to a combustion chamber 21 of a turbomachine. The fuel supply circuit 1 comprises a low-pressure pump 11 connected to the tank 10, a filter 12, a high-pressure pump 13, a metering device 14, and an oil / fuel heat exchanger 15 connected to the combustion chamber 21. The turbomachine includes, in particular, a gearbox 17 ("gearbox") to which a drive shaft 18 is connected for delivering mechanical power. The low-pressure pump 11 and the high-pressure pump 13 are centrifugal pumps mechanically coupled to the drive shaft.

[0036] According to the invention, an electromagnetic pump 20 is further associated here with the low-pressure centrifugal pump 11. The electromagnetic pump 20 is, for example, of the liquid ring type, the side channel type, the regenerative type, or the gerotor type, independently controlled, for example, by the digital computer 16 integrated into the turbomachine control unit. As described in detail below, the rotor of the electromagnetic pump 20 is connected to the drive shaft 18 by a one-way clutch element. Both the low-pressure centrifugal pump 11 and the electromagnetic pump 20 are connected to the fuel supply line.More specifically, the inlet of pumps 11 and 20 is connected to the fuel tank 10 while the outlet of pumps 11 and 20 is connected to the filter 12 so that the turbomachine can be supplied with fuel by the low pressure centrifugal pump 11, or by the electromagnetic pump 20, or by both pumps 11 and 20 simultaneously.

[0037] We now describe different embodiments of an electromagnetic pump which can be used in the present invention such as for example for the electromagnetic pump 20 described above.

[0038] Figure 2 illustrates an electromagnetic pump 100 according to an embodiment of the invention. In the example described here, the electromagnetic pump 100 is a liquid ring pump comprising a fixed pump body or stator 110 made up of half-casings 111 and 112. The half-casing 111 and, respectively, 112, have a solid cylindrical central portion 1110, respectively 1120, provided with a suction / discharge port 1111, respectively 1121, and a circular outer wall 1112, respectively 1122, extending concentrically around the central portion 1110, respectively 1120. An annular housing 1113, respectively 1123, is defined between the central portion 1110, respectively 1120, and the outer wall 1112, respectively 1122.

[0039] The electromagnetic pump 100 also includes an impeller or rotor 120 comprising a wheel 121 equipped with a plurality of blades 122 extending from the wheel in a radial direction DR. The impeller 120 has a bearing 124. Openings 1114 and 1124 are present on the half-casing 111 and the half-casing 112, respectively. The bearing 1124 is designed to cooperate with a freewheel 150, which here forms the one-way clutch element connecting the drive shaft 18 to the impeller 120 of the electromagnetic pump 100, the openings 1114 and 1124 allowing passage of the drive shaft 18.In liquid ring type pumps, the free wheel 150 is placed eccentrically on the impeller 120, for example by means of a spacer (not shown in Figure 2), so as to create inter-blade (or inter-vane) volume variations which allow the pumped fluid to be drawn in, for example through port 1111 and then discharged under pressure, for example through port 1121. The pump 100 can also be a side channel pump, also called a regenerative pump. In this case, a lateral channel 1125 (shown as a dotted line in Figure 2) present here on the half-casing 112 extends between ports 1111 and 1121. The evolution of the inter-blade (or inter-blade) volume variations, associated with the velocity field (vortex) present in the lateral channel 1125, allows the fluid to be drawn in, for example through port 1111, and then discharged under pressure, for example through port 1121.The electromagnetic pump 100 further comprises a plurality of permanent magnets 130 distributed annularly on the impeller or rotor 120 and a plurality of coils 140 distributed annularly inside the fixed pump body or stator 110. More specifically, in the example described here, the permanent magnets 130 are held on the radially external ends of the blades 122 while the coils 140 are held on the internal surface of a support ring 141, the coil and support ring assembly being present both in the annular housing 1113 of the half-casing 111 and in the annular housing 1123 of the half-casing 112.

[0040] Once all the constituent elements of the pump 100 are assembled, the permanent magnets 130 are opposite the coils 140 in a radial direction DR as illustrated in Figure 3. The control of the electromagnetic pump 100 (torque and rotational speed) is achieved by controlling the current flowing in the coils.

[0041] By fixing the permanent magnets 130 directly onto the impeller 120, part of the pump drive means is integrated directly into the moving parts, which allows for a high level of integration of the drive means and therefore a reduced footprint for the pump.

[0042] Furthermore, by placing the plurality of permanent magnets and the plurality of coils opposite each other in the radial direction, the radial dimensions of the pump are greatly optimized. This results in a very compact pump that can be driven independently of the engine speed of the turbomachine with which it is coupled.

[0043] Figure 4 shows an electromagnetic pump 200 according to another embodiment of the invention. In this embodiment, the pump 200 is a gerotor-type pump comprising a fixed pump body or stator 210 consisting of a housing 211 and a flange 212. The housing 211 has an internal compartment 2113 delimited by an external wall 2112. The flange 212 has a suction port 2120 and a discharge port 2121.

[0044] The electromagnetic pump 200 also includes a rotor 220 comprising an internal pinion 221 and an external ring gear 222. The internal pinion 221 has an external toothing consisting of six teeth 2210, while the external ring gear 222 has an internal toothing consisting of seven teeth 2220. The internal pinion 221 has a bearing 224. Openings 2114 and 2124 are present on the housing 211 and the flange 212, respectively. The bearing 224 is designed to cooperate with a freewheel 250, which here forms the one-way clutch element connecting the drive shaft 18 to the rotor 220 of the electromagnetic pump 200. The openings 2114 and 2124 allow passage of the drive shaft 18.

[0045] In gerotor-type pumps, a fluid is drawn in from port 2120 and discharged via port 2121 by capsules created between teeth 2210 and 2220 respectively of the inner pinion 221 and outer ring 222 during the rotation of these two elements.

[0046] The electromagnetic pump 200 further comprises a plurality of permanent magnets 230 distributed annularly on the outer periphery of the outer ring 222 and a plurality of coils 240 distributed annularly inside the fixed pump body or stator 210. More specifically, the coils 240 are held on the inner surface of a support ring 241, the coil and support ring assembly being present in the internal housing 2113 of the casing 211.

[0047] Once all the components of the pump 200 are assembled, the permanent magnets 230 are positioned opposite the coils 240 in a radial direction D Ras illustrated in figure 5. The control of the electromagnetic pump 200 (torque and rotational speed) is achieved by controlling the current flowing in the coils.

[0048] By fixing the permanent magnets 230 directly onto the internal pinion 221, part of the pump drive means is integrated directly within the moving elements, which allows for a high level of integration of the drive means and therefore a reduced footprint for the pump.

[0049] Furthermore, by placing the plurality of permanent magnets and the plurality of coils opposite each other in the radial direction, the radial dimensions of the pump are greatly optimized. This results in a very compact pump that can be driven independently of the engine speed of the turbomachine with which it is coupled.

[0050] Figure 6 illustrates an electromagnetic pump 300 according to another embodiment of the invention. In the example described here, the electromagnetic pump 300 is a liquid ring pump comprising a fixed pump body or stator 310 consisting of a casing 311 and a flange 312. The casing 311 has a solid cylindrical central portion 3110 provided with a suction / discharge port 3111 and a circular outer wall 3112 extending concentrically around the central portion 3110, with annular recesses 3113 being defined between the central portion 1110 and the outer wall 3112. The flange 312 has a discharge / suction port 3120.

[0051] The electromagnetic pump 300 also includes an impeller or rotor 320 comprising an impeller 321 with a plurality of blades 322 extending from the impeller in a radial direction DR, a ring 323 being present at the outer periphery of the impeller. In the example described here, the ring 323 is fixed to the radially outer ends of the blades 322.

[0052] The impeller 320 includes a bearing 324. Openings 3114 and 3124 are present on the half-casing 311 and half-casing 312, respectively. The bearing 324 is designed to cooperate with a freewheel 350, which here forms the one-way clutch element connecting the drive shaft 18 to the impeller 320 of the electromagnetic pump 300. The openings 3114 and 3124 allow the passage of the drive shaft 18. The bearing 324 is positioned eccentrically on the impeller 320 to create inter-blade volume variations that allow the pumped fluid to be drawn in, for example, through port 3111, and then discharged under pressure, for example, through port 3120. The pump 300 can also be a side channel pump, also called a regenerative pump. In this case, a lateral channel 3125 (shown as a dotted line in Figure 6) present here on the flange 312 extends between ports 3111 and 3120.The evolution of the inter-blade volume variations, combined with the velocity field (vortex) present in the lateral channel 3125, allows the fluid to be drawn in, for example through port 3111, and then discharged under pressure, for example through port 3120. The electromagnetic pump 300 further comprises a plurality of permanent magnets 330 distributed annularly on the impeller or rotor 320 and a plurality of coils 340 distributed annularly inside the fixed pump body or stator 310. More precisely, in the example described here, the permanent magnets 330 are held in housings 3230 in the ring 323, while the coils 340 are held in the annular housing 3113 in the casing 311.

[0053] Once all the components of the pump 300 are assembled, the coils 340 are positioned opposite the permanent magnets 330 along an axial direction D AThe control of the electromagnetic pump 300 (torque and rotational speed) is achieved by controlling the current flowing in the coils.

[0054] By fixing the permanent magnets 330 directly onto the impeller 320, part of the pump drive means is integrated directly into the moving parts, which allows for a high level of integration of the drive means and therefore a reduced footprint for the pump.

[0055] Furthermore, by positioning the plurality of permanent magnets and the plurality of coils opposite each other along the axial direction, the radial dimensions of the pump are greatly optimized. This results in a very compact pump that can be driven independently of the engine speed of the turbomachine with which it is coupled.

[0056] Figure 7 illustrates another embodiment of an electromagnetic pump 400 that differs from the electromagnetic pump 300 described in relation to Figure 6 in that it includes a double winding. More specifically, as with the pump 300, the pump 400 comprises an impeller or rotor 420 including an impeller 421 equipped with a plurality of blades 422 extending from the impeller in a radial direction DR, and a ring 423 fixed to the radially external ends of the blades 422.

[0057] The electromagnetic pump 400 also includes a fixed pump body or stator 410 consisting of a first housing 411 and a second housing 412. The housings 411 and 412 each have, respectively, a solid cylindrical central portion 4110, 4120 provided with a suction / discharge port 4111, 4121 and a circular outer wall 4112, 4122 extending concentrically around the central portion 4110, 4120. First annular housings 4113 are defined in the first housing 411 between the central portion 4110 and the outer wall 4112. Second annular housings 4123 are defined in the second housing 412 between the central portion 4120 and the outer wall 4122.

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

[0059] The impeller 420 has a bearing 424. Openings 4114 and 4124 are present respectively on the half-case 411 and the half-case 412. The bearing 424 is intended to cooperate with a free wheel 450 forming here the one-way clutch element connecting the drive shaft 18 to the impeller 420 of the electromagnetic pump 400, the openings 4114 and 4124 allowing the passage of the drive shaft 18.

[0060] Once the pump 400 is assembled, the first and second plurality of coils 440 and 445 are located respectively on one side and the other side of the wheel 420 and opposite the magnets along an axial direction D A .

[0061] In addition to the integration and compactness advantages already mentioned for the 300 pump, the 400 electromagnetic pump includes two sets of coils, ensuring redundancy in case of failure or malfunction of one coil. Each set of coils has its own connections to the control system. This coil redundancy can also be used to double the strength of the electromagnetic fields to which the permanent magnets are subjected. It should also be noted that, again with a view to optimizing the pump's footprint, only the coil set is redundant, and this is located as close as possible to the permanent magnets. The 400 pump can also be a side channel pump, also known as a regenerative pump, as explained previously in relation to the 300 pump.

[0062] Figure 8 shows an electromagnetic pump 500 according to another embodiment of the invention. In this embodiment, the pump 500 is a gerotor-type pump comprising a fixed pump body or stator 510 consisting of a casing 511 and a flange 512. The casing 511 has a solid cylindrical central portion 5110 and a circular outer wall 5112 extending concentrically around the central portion 5110, with annular recesses 5113 being defined between the central portion 5110 and the outer wall 5112. The flange 512 has a suction port 5120 and a discharge port 5121. The electromagnetic pump 500 also includes a rotor 520 comprising an inner pinion 521 and an outer ring 522 surrounding the inner pinion 521 in a radial direction DR.The inner pinion has an outer toothing consisting of six teeth 5210, while the outer ring gear 522 has an inner toothing consisting of seven teeth 5220. The inner pinion 521 has a bearing 524. Openings 5114 and 5124 are present on the housing 511 and the flange 512, respectively. The bearing 524 is designed to cooperate with a freewheel 550, which here forms the one-way clutch element connecting the drive shaft 18 to the rotor 520 of the electromagnetic pump 500. The openings 5114 and 5124 allow passage of the drive shaft 18. In gerotor-type pumps, a fluid is drawn in from port 5120 and discharged via port 5121 through capsules formed between the teeth 5210 and 5220 of the inner pinion 521 and the outer ring gear, respectively. 522 during the rotation of these two elements.

[0063] The electromagnetic pump 500 further comprises a plurality of permanent magnets 530 distributed annularly on the outer periphery of the outer ring 522 and a plurality of coils 540 distributed annularly inside the fixed pump body or stator 510. More specifically, in the example described here, the permanent magnets 530 are held in housings 5221 present in the outer ring 522 while the coils 540 are held in annular housings 5113 present in the casing 511.

[0064] Once all the components of the pump 500 are assembled, the coils 540 are positioned opposite the permanent magnets 530 along an axial direction D A The control of the electromagnetic pump 500 (torque and rotational speed) is achieved by controlling the current flowing in the coils.

[0065] By fixing the permanent magnets 530 directly onto the outer ring 522, part of the pump drive means is integrated directly within the moving elements, which allows for a high level of integration of the drive means and therefore a reduced footprint for the pump.

[0066] Furthermore, by positioning the plurality of permanent magnets and the plurality of coils opposite each other along the axial direction, the radial dimensions of the pump are greatly optimized. This results in a very compact pump that can be driven independently of the engine speed of the turbomachine with which it is coupled.

[0067] The electromagnetic pump 500 can also be equipped with a double winding as described for the pump 400 in Figure 7. In this case, the pump includes a second plurality of coils distributed in an annular manner in housings present in the flange 512.

[0068] Figure 9 illustrates another embodiment of an electromagnetic pump 600 that differs from the electromagnetic pump 500 described in relation to Figure 8 in that the permanent magnets are held on the inner pinion. More specifically, as with the pump 500, the gerotor-type pump 600 comprises a fixed pump body or stator 610 consisting of a housing 611 and a flange 612. The housing 611 has annular recesses 6113. The flange 612 has a suction port 6120 and a discharge port 6121.

[0069] The electromagnetic pump 600 also includes a rotor 620 comprising an inner pinion 621 and an outer ring 622 surrounding the inner pinion 621 in a radial direction DR. The inner pinion has an outer set of six teeth 6210, while the outer ring 622 has an inner set of seven teeth 6220. The inner pinion 621 has a bearing 624. Openings 6114 and 6124 are present on the housing 611 and the flange 612, respectively. The bearing 624 is designed to cooperate with a freewheel 150, which here forms the one-way clutch element connecting the drive shaft 18 to the rotor 620 of the electromagnetic pump 600. The openings 6114 and 6124 allow passage of the drive shaft 18.

[0070] The electromagnetic pump 600 further comprises a plurality of permanent magnets 630 held annularly in the inner pinion 621 around the bearing 624 and a plurality of coils 640 held in the annular housings 6113 in the casing 611. Once all the components of the pump 600 are assembled, the coils 640 are positioned opposite the permanent magnets 630 along an axial direction D A The control of the electromagnetic pump 600 (torque and rotational speed) is achieved by controlling the current flowing in the coils.

[0071] By fixing the permanent magnets 630 directly onto the inner pinion 621, part of the pump drive means is integrated directly into the moving elements, which allows for a high level of integration of the drive means and therefore a reduced footprint for the pump.

[0072] Furthermore, by positioning the plurality of permanent magnets and the plurality of coils opposite each other along the axial direction, the radial dimensions of the pump are greatly optimized. This results in a very compact pump that can be driven independently of the engine speed of the turbomachine with which it is coupled.

[0073] As with the pumps described previously, the electromagnetic pump 600 can be equipped with a double winding, namely comprising first and second plurality of coils present respectively on one side and the other side of the inner pinion, the coils of the first and second plurality of coils being opposite the magnets along the axial direction.

[0074] According to an additional feature of the invention, the permanent magnets present on the radially external ends of the impeller blades for the embodiments described above in relation to Figures 2, 3, 6, and 7, or on the outer ring for the embodiments described above in relation to Figures 4, 5, and 8, or on the inner pinion for the embodiment described above in relation to Figure 9, can be arranged in a Halbach structure. Figure 10 illustrates an example of the permanent magnet arrangement in a Halbach structure. In this example, permanent magnets 30 are distributed annularly as in the rotors described above, with the polarity of the magnets reversed in the radial and circumferential directions, as indicated by the arrows in Figure 10.This particular arrangement increases the magnetic field 40 on the outer side of the rotor while the magnetic field on the inner side of the rotor is essentially canceled out. This reduces the loss of the magnetic field, thus improving the control of the rotor by the coils.

[0075] The one-way clutch element, such as the freewheel described above, allows the rotor of the electromagnetic pump to be selectively coupled to the drive shaft used to drive the centrifugal pump. This makes it possible to use the electromagnetic pump in several operating modes within the turbomachine.

[0076] One operating mode involves priming the turbomachine's fuel supply circuit when the engine is off. At this stage, the fuel supply circuit may contain air due to a complete or partial draining of the fuel line between the tank and the turbomachine's combustion chamber. The presence of air significantly reduces the suction capacity of the centrifugal pump, which can even prevent the engine from starting. A known solution from prior art involves equipping the tank with a priming pump, also called a "lift pump," which fills the fuel supply circuit between the tank and the engine. However, implementing a lift pump within a tank is complex and increases the overall mass, while the pump is only used for potential priming before engine start-up.

[0077] According to the invention, the fuel supply circuit is primed by controlling the electromagnetic pump from an independent electrical power source to fill the fuel supply circuit before the engine starts. In this first operating mode, referred to as the "priming mode," the rotor of the electromagnetic pump rotates freely around the motor shaft, which is held stationary by the presence of the one-way clutch element interposed between the rotor and the motor shaft.

[0078] A second operating mode, called "boost mode," is implemented while the engine is running and the centrifugal pump is driven by the drive shaft. In this mode, the rotor of the electromagnetic pump is driven from an independent electrical power source at a speed higher than the rotational speed of the drive shaft, thus providing additional pumping capacity to the centrifugal pump. The one-way clutch allows the rotor of the electromagnetic pump to rotate at a speed higher than the rotational speed of the drive shaft.

[0079] A third operating mode, called "generator mode," is implemented when the engine is running and the centrifugal pump is driven by the drive shaft. The electromagnetic pump is not powered by an electrical energy source, but its rotor is driven by the drive shaft via a one-way clutch interposed between the rotor and the drive shaft. In this mode, the electromagnetic pump acts as an electrical generator, producing an electric current that can be drawn from the pump's coils and stored in batteries for later use, for example, to control the electromagnetic pump in the first two operating modes.

Claims

Demands

1. Fuel supply circuit (1) of an aircraft engine connecting a fuel tank (10) to a combustion chamber (21) of a turbomachine, comprising at least one centrifugal pump (11) mechanically coupled with a drive shaft (18), characterized in that it further comprises at least one electromagnetic pump (100) comprising at least one stator (110) delimiting an annular internal volume in which is present a rotor (120) capable of driving a fluid, a plurality of magnets (130) distributed annularly on the rotor (120) and at least one plurality of coils (140) distributed annularly inside the stator (110) opposite the magnets (130) and in that the rotor (120) is connected to the drive shaft (18) by a one-way clutch element (150).

2. Circuit according to claim 1, wherein the rotor (120) comprises a wheel (121) provided with a plurality of blades (122), the magnets of the plurality of magnets (130) being held at the radially external ends of the wheel blades, the coils of the plurality of coils (140) being opposite the magnets of the plurality of magnets (130) in a radial direction (DR).

3. Circuit according to claim 1, wherein the rotor (220) comprises an inner pinion (221) cooperating with an outer ring (222) having internal teeth, the magnets of the plurality of magnets (230) being held at the outer periphery of the outer ring (222), the coils of the plurality of coils (240) being opposite the magnets of the plurality of magnets (230) in a radial direction (D R ).

4. A circuit according to claim 1, wherein the rotor (320) comprises a wheel (321) provided with a plurality of blades (322), the magnets of the plurality of magnets (330) being held at the outer periphery of the wheel, the coils of the plurality of coils (340) being opposite the magnets (330) in an axial direction (D A ).

5. Circuit according to claim 4, wherein each electromagnetic pump (400) comprises first and second pluralities of coils (440, 450) present respectively on one side and the other side of the wheel (421), the coils of the first and second plurality of coils being opposite the magnets along the axial direction (D A ).

6. Circuit according to claim 1, wherein the rotor (520) comprises an inner pinion (521) cooperating with an outer ring (522) having internal teeth, the magnets of the plurality of magnets (530) being held at the outer periphery of the outer ring, the coils of the plurality of coils (540) being opposite the magnets (530) in an axial direction (D A ).

7. Circuit according to claim 6, wherein each electromagnetic pump (400) comprises first and second pluralities of coils (440, 450) located respectively on one side and the other side of the outer ring (422), the coils of the first and second pluralities of coils (440, 450) being opposite the magnets (430) along the axial direction (D A ).

8. Circuit according to claim 1, wherein the rotor (620) comprises an inner pinion (621) cooperating with an outer ring gear (622) having internal teeth, the magnets of the plurality of magnets (630) being held on the inner pinion (621), the coils of the plurality of coils (640) being opposite the magnets (630) in an axial direction (D A ).

9. Circuit according to claim 8, wherein each electromagnetic pump comprises first and second pluralities of coils located respectively on one side and the other side of the pinion, the coils of the first and second pluralities of coils being opposite the magnets along the axial direction (D A ).

10. Circuit according to any one of claims 1 to 9, wherein each electromagnetic pump is capable of generating an electric current.

11. Aircraft engine comprising a fuel supply circuit according to any one of claims 1 to 10.

12. Use of the fuel supply circuit according to any one of claims 1 to 10 for the fuel supply of an aircraft engine, said circuit being connected to a fuel tank without a priming pump.