ASSEMBLY INCLUDES A HOUSING, AN OIL CIRCUIT AND A FUEL CIRCUIT

Abstract

Assembly (12) for an aircraft turbomachine comprising: - a housing (14) including a casing (15) and gears (16a-16d), the gears (16a-16d) being arranged inside the casing (15) and meshed with each other; - an oil circuit (17) including an oil reservoir (18), the oil reservoir (18) including a casing (19) which is integral with the casing (15) of the housing (14); - a fuel circuit (20) including at least one piece of equipment (21, 22a-22d); characterized in that the equipment (21a, 22a-22d) of the fuel circuit (20) is fixed to the oil reservoir (18), to allow heat exchange between the fuel circuit (20) and the oil circuit (17). Figure for the abridged version: 2

Description

Title of the invention: ASSEMBLY COMPRISING A HOUSING, AN OIL CIRCUIT AND A FUEL CIRCUIT Technical field of the invention

[0001] The present invention relates to an assembly for an aircraft turbomachine comprising a housing, an oil circuit and a fuel circuit, as well as an aircraft turbomachine comprising such an assembly. Technical background

[0002] An aircraft turbomachine includes in particular various transmission elements (for example gears) and guidance elements (for example rolling bearings or hydrodynamic bearings) which are lubricated with oil via an oil circuit.

[0003] The oil circuit includes an oil reservoir and various components, including a lubrication unit that circulates the oil within the circuit. The lubrication unit is externally mounted on an accessory housing (hereinafter referred to as the "housing") and driven by it. The oil reservoir is traditionally located in the same area as the housing to minimize the size of the pipes connecting the oil reservoir and the lubrication unit.

[0004] Note that it is known from document EP2391803B1 in the name of the applicant to integrate the oil reservoir of the oil circuit into the housing.

[0005] The turbomachine also includes a gas generator which conventionally comprises at least one compressor, one combustion chamber, and at least one expansion turbine (or high-pressure turbine). The combustion chamber of the gas generator is supplied with fuel via a fuel circuit.

[0006] The fuel system comprises a fuel tank and various components, including fuel / oil heat exchangers, fuel filters, a fuel pump (also known as the MFP for "Main Fuel Pump"), and a fuel regulator (also known as the FMU for "Fuel Monitor Unit"). The aforementioned fuel system components are also externally mounted on the housing, with the fuel pump also being driven by the housing. The fuel / oil heat exchangers simultaneously heat the fuel before injection and cool the oil before reinjection. For an aircraft, for example, the fuel tank is located in the wings.

[0007] The housing is known by the English acronym AGB for "Accessory GearBox". As indicated above, the housing is associated with various components of the oil and fuel circuits, as well as with equipment necessary for the operation of The turbomachine and the aircraft (including an electric generator, a starter, etc.). The housing is rotationally coupled to the rotor of the gas generator, so as to drive the various components or to drive the rotor of the gas generator via one of the components (including the starter). For a turbofan engine, the equipped housing (i.e., the housing with its components) and the oil reservoir are typically mounted in an area commonly called the "fan zone" (or "blower zone" in French), which corresponds to the area around the fan casing.

[0008] Engine manufacturers today are seeking to reduce the size of the assembly comprising the equipped housing and the oil reservoir, in order to generally optimize the overall performance of a turbomachine.

[0009] This reduction in size is crucial when the assembly (equipped housing and oil reservoir) is mounted directly around the gas generator in an area commonly referred to as the "core zone." Indeed, the available space in the "core zone" is less than in the "fan zone," so it is essential to find solutions to accommodate the aforementioned assembly without compromising the optimal aerodynamic lines defined by the engine manufacturers.

[0010] Mounting the assembly (equipped casing and oil reservoir) in the "core zone" is unavoidable when the turbomachine includes one or more unducted fans, since the "fan zone" no longer exists. Such a turbomachine is, for example, known by the English acronym USF for "Unducted Single Fan," this USF turbomachine comprising a single unducted fan.

[0011] The objective of the present invention is therefore to provide a simple, effective and economical solution to the aforementioned problem. Summary of the invention

[0012] The invention thus proposes an assembly for an aircraft turbomachine comprising: - a housing comprising a casing and gears, the gears being arranged inside the casing and meshed with each other; - an oil circuit including an oil reservoir, the oil reservoir including a casing which is one piece with the casing of the housing; - a fuel circuit including at least one piece of equipment; characterized in that the fuel circuit equipment is fixed to the oil tank, to allow heat exchange between the fuel circuit and the oil circuit.

[0013] Such heat exchange between the fuel circuit and the oil circuit (and more specifically between the equipment and the oil tank) allows the fuel to take heat from the oil (hot source) and the oil to remove heat from the fuel (cold source).

[0014] Such heat exchange thus makes it possible to reduce the fuel heating and oil cooling requirements, and thus to reduce the number and / or size of the fuel / oil heat exchangers which are conventionally used to heat the fuel and cool the oil, and consequently to reduce the overall size of the assembly.

[0015] The heat exchange between the fuel circuit and the oil circuit is obtained in particular by thermal conduction.

[0016] In addition, fixing the fuel circuit equipment to the oil tank housing also improves the compactness of the assembly.

[0017] Finally, the integration of the oil reservoir into the housing also contributes to reducing the overall size of the assembly.

[0018] The assembly according to the invention may include one or more of the following features, taken individually or in combination with each other: - the fuel circuit equipment is fixed directly onto the oil tank casing; - the fuel circuit equipment is part of a fuel plate which includes a support on which the equipment is fixed, the support being fixed to the oil tank casing; - the fuel plate support includes at least one internal fuel channel; - the support includes fins placed inside the oil reservoir; - the fuel system includes at least one fuel line that passes through the oil tank; - the oil circuit includes at least one oil line that passes through a fuel tank; - the fuel circuit includes a fuel pump which is attached externally to the housing of the casing, the fuel pump being driven in rotation by one of the toothed wheels; - the oil circuit includes a lubrication unit which is externally mounted on the housing of the casing, the lubrication unit comprising an oil supply pump and an oil recovery pump which are driven in rotation by one of the toothed wheels.

[0019] The present invention also relates to an aircraft turbomachine comprising an assembly as described above. Brief description of the figures

[0020] The invention will be better understood and other details, features and advantages of the invention will become more apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings in which:

[0021] [Fig-1] [Fig.1] is a schematic longitudinal half-section view of a turbomachine comprising an assembly according to the invention;

[0022] [Fig.2] [Fig.2] is a schematic view of the assembly. Detailed description of the invention

[0023] Figure 1 schematically represents a turbomachine 1 with longitudinal axis X for an aircraft 2, such as an airplane.

[0024] The turbomachine 1 comprises a movable, unfaired fan 3 and a fixed, unfaired rectifier 4. Such a turbomachine 1 is more commonly known by the English acronym USF for "Unducted Single Fan".

[0025] As illustrated in [Fig. 1], the fan 3 is free to rotate about the X-axis. The fan 3 is driven in rotation by a power turbine 5 connected to a gas generator 6, the power turbine 5 and the gas generator 6 both being located downstream of the fan 3. The fan 3 is driven in rotation by the power turbine 5 via a speed reducer 7. The speed reducer 7 reduces the rotational speed of the fan 3 relative to that of the power turbine 5, while increasing its torque. The speed reducer 7 is, for example, an epicyclic gear reducer. The fan 3 has an annular row of blades 8 with fixed or variable pitch.

[0026] The straightener 4 is fixed in rotation about the X axis. The straightener 4 is configured to straighten at least part of the airflow F generated by the blower 3. The straightener 4 is arranged here directly downstream of the blower 3. The straightener 4 comprises an annular row of guide vanes 9 with fixed or variable pitch.

[0027] The gas generator 6 conventionally comprises, from upstream to downstream along the direction of airflow F, at least one compressor, one combustion chamber, and at least one expansion turbine (or high-pressure turbine). The rotors of a compressor and an expansion turbine of the same body are rotationally linked to each other via one or more drive shafts.

[0028] When the turbomachine 1 operates in "propulsion" mode, the fan 3 generates an airflow F which flows around the fairings of the nacelle 10, so as to propel the aircraft 2. The gas generator 6 is supplied by an air inlet 11 which opens between the fan 3 and the rectifier 4.

[0029] The turbomachine 1 further comprises an assembly 12 according to the invention which is arranged around the gas generator 6 in a zone 13 called the core (or "zone core" in English) since it is located in the central part of the turbomachine 1.

[0030] The example illustrated in [Fig.1] is in no way limiting; the assembly 12 according to the invention could be placed in another location and in other types of turbomachine 1, for example a turboprop, a turbojet, a turbomotor, or even a turbomachine generally comprising one or more shrouded or unshrouded fans.

[0031] Set 12 comprises: - a housing 14 (or an accessory housing) comprising a casing 15 and gear wheels 16a-16d, the gear wheels 16a-16d being arranged inside the casing 15 and meshed with each other; - an oil circuit 17 comprising an oil reservoir 18, the oil reservoir 18 comprising a casing 19 which is one piece with the casing 15 of the housing 14; - a fuel circuit 20 comprising at least one piece of equipment 21, 22a-22d.

[0032] According to the invention, the equipment 21, 22a-22d of the fuel circuit 20 is fixed to the oil reservoir 18, to allow heat exchange between the fuel circuit 20 and the oil circuit 17.

[0033] Such heat exchange between the fuel circuit 20 and the oil circuit 17 (and more specifically between the equipment 21, 22a-22d and the oil tank 18) allows the fuel to take heat from the oil (hot source) and the oil to remove heat from the fuel (cold source).

[0034] Such heat exchange thus makes it possible to reduce the fuel heating and oil cooling requirements, and thus to reduce the number and / or size of the fuel / oil heat exchangers which are conventionally used to heat the fuel and cool the oil, and consequently to reduce the overall size of the assembly 12.

[0035] The heat exchange between the fuel circuit 20 and the oil circuit 17 is obtained in particular by thermal conduction.

[0036] In addition, the fixing of the equipment 21, 22a-22d of the fuel circuit 20 on the casing 19 of the oil tank 18 also makes it possible to improve the compactness of the assembly 12.

[0037] Finally, the integration of the oil reservoir 18 into the housing 14 also contributes to reducing the overall size of the assembly 12.

[0038] By convention in this application, "axial" or "axially" means any direction parallel to the X-axis of the turbomachine 1, and "radial" or "radially" means any direction perpendicular to the X-axis of the turbomachine 1.

[0039] The oil circuit 17 is conventionally used to lubricate various transmission and guidance elements located in different lubrication chambers of the turbomachine 1. The oil circuit 17 is closed and thus forms a loop in which the oil circulates.

[0040] The fuel circuit 20 is conventionally used to supply fuel to the combustion chamber of the gas generator 6. The fuel circuit 20 is open, with fuel being injected into the combustion chamber to be mixed with compressed air.

[0041] The equipment 21, 22a-22d of the fuel circuit 20 which is mounted on the casing 19 of the oil tank 18 is arbitrary, and may thus correspond, for example, to a fuel / oil heat exchanger, a fuel filter, or a fuel regulator (also known by the English acronym FMU for "Fuel Monitor Unit").

[0042] The fuel circuit 20 can obviously include several pieces of equipment 21, 22a-22d fixed directly or indirectly to the casing 19 of the oil reservoir 18, so as to increase the heat exchange between the fuel circuit 20 and the oil circuit 17.

[0043] One or more pieces of equipment 21 of the fuel circuit 20 can be fixed directly to the casing 19 of the oil tank 18. One piece of equipment 21 is for example fixed directly to an interface of the casing 19 of the oil tank 18. The interface is for example formed by a boss.

[0044] One or more pieces of equipment 22a-22d of the fuel circuit 20 may be part of a fuel plate 23 which includes a support 24 on which the piece(s) of equipment 22a-22d are fixed, the support 24 being fixed to the casing 19 of the oil tank 18. Such a fuel plate 23 is also known by the English term "fuel plate".

[0045] Advantageously, the support 24 of the fuel plate 23 includes at least one internal fuel line. Such a positioning of the internal fuel line makes it possible to create additional heat exchange between the fuel circuit 20 and the oil circuit 17 (and more specifically between the internal fuel line and the oil reservoir 18).

[0046] Advantageously, the support 24 of the fuel plate 23 includes fins placed inside the oil reservoir 18. Such fins make it possible to increase the exchange surface, and consequently to maximize the heat exchange between the fuel circuit 20 and the oil circuit 17.

[0047] Advantageously, the fuel circuit 20 includes at least one fuel line that passes through the oil reservoir 18. Such a positioning of the fuel line allows for additional heat exchange between the circuit and fuel 20 and the oil circuit 17 (and more specifically between the fuel line and the oil tank 18).

[0048] Advantageously, the oil circuit 17 includes at least one oil line that passes through a fuel tank. Such a positioning of the oil line allows for additional heat exchange between the fuel circuit 20 and the oil circuit 17 (and more specifically between the oil line and the fuel tank). When the aircraft 2 is an airplane, the fuel tank is traditionally located in the wings of the airplane.

[0049] Advantageously, the fuel circuit 20 includes a fuel pump 25 (also known by the English acronym MFP for "Main Fuel Pump") which is externally mounted on the housing 15 of the casing 14, the fuel pump 25 being driven in rotation by one of the gears 16a-16d. The fuel pump 25 allows the fuel to circulate in the fuel circuit 20 from the fuel tank to the combustion chamber.

[0050] Advantageously, the oil circuit 17 includes a lubrication unit 26 which is externally mounted on the housing 15 of the casing 14, the lubrication unit 26 comprising an oil supply pump and an oil recovery pump which are driven in rotation by one of the gears 16a-16d. The lubrication unit 26 allows the oil to circulate in the oil circuit 17 from the oil reservoir 18 to the lubrication chambers via the supply pump, but also from the lubrication chambers to the oil reservoir 18 via the recovery pump.

[0051] The supply and recovery pumps can each comprise several pump modules arranged axially next to each other.

[0052] Advantageously, the equipment 21, 22a-22d of the fuel circuit 20 and / or the support 24 of the fuel plate 23 and / or the housing 19 of the oil reservoir 18 are made partly or entirely of a material which has high thermal conductivity (for example aluminium or aluminium alloy), so as to promote heat exchange between the fuel circuit 20 and the oil circuit 17.

[0053] According to the embodiment illustrated in the figures, and in particular in [Fig. 2], the housing 15 of the casing 14 and the housing 19 of the oil reservoir 18 are butted (or joined) to each other. The two housings 15, 19 form an arched (or curved) block designed to fit the circular circumference of a structural housing to which the block is fixed by means of various brackets. The two housings 15, 19 can be grouped or combined into a single piece, thus obtaining a single, one-piece housing. Alternatively, the two housings 15, 19 can be separate, placed one on top of the other, and fixed to one another. to the other (for example by clamping). The housings 15, 19 can be obtained by molding, by machining from a block of material or by additive manufacturing.

[0054] More specifically, as illustrated in [Fig. 2], the housing 15 of the casing 14 comprises first and second walls 27, 28 facing each other. The first and second walls 27, 28 of the housing 15 of the casing 14 are connected to each other by a peripheral wall 29. The casing 14 internally comprises gears 16a-16d which are meshed with each other to form a gear train 30.

[0055] The gear train 30 is rotationally coupled with a rotor of the gas generator 6 via an input gearbox 31 (also known by the English acronym IGB for "Inlet GearBox"), a radial drive shaft 32 (also known by the English acronym RDS for "Radial Drive Shaft"), a transfer gearbox 33 (also known by the English acronym TGB for "Transfer GearBox") and a horizontal drive shaft 34 (also known by the English acronym HDS for "Horizontal Drive Shaft").

[0056] The various gear wheels 16a-16d are coupled in rotation with different elements or equipment, to drive them or to be driven by them.

[0057] More specifically, the toothed wheel 16a is coupled in rotation with the horizontal drive shaft 34.

[0058] The gear 16b is rotationally coupled to a fuel pump 25 of the fuel circuit 20 and a lubrication unit 26 of the oil circuit 17. The fuel pump 25 is externally mounted on the first wall 27 of the housing 15 of the casing 14. The lubrication unit 26 is externally mounted on the second wall 28 of the housing 15 of the casing 14. The lubrication unit 26 comprises an oil supply pump and an oil recovery pump which are driven in rotation by the gear 16b.

[0059] The toothed wheel 16c is coupled in rotation with a piece of equipment 35 of the oil circuit 17. The piece of equipment 35 is attached externally to the second wall 28 of the housing 15 of the casing 14.

[0060] The toothed wheel 16d is coupled in rotation with another piece of equipment 36 (for example an electric generator) which is external to the oil and fuel circuits 17, 20. The equipment 36 is attached externally to the second wall 28 of the housing 15 of the casing 14.

[0061] As illustrated in [Fig. 2], the oil reservoir 19 also comprises first and second walls 37, 38 facing each other. The first and second walls 37, 38 of the oil reservoir 19 are connected to each other by a peripheral wall 39. The oil reservoir 19 forms an enclosure 40 in which the oil from the oil circuit 17 is stored. The enclosure 40 of the oil reservoir 18 is independent and separate from the enclosure 41 of the housing 14. In other words, The enclosure 40 of the oil reservoir 18 does not communicate with the enclosure 41 of the housing 14.

[0062] The fuel circuit 20 includes a fuel plate 23 having a support 24 on which four components 22a-22d of the fuel circuit 20 are mounted. More specifically, each of the four components 22a-22d is flanged to an interface formed on the support 24. These four components 22a-22d include a fuel filter and a fuel regulator. The support 24 of the fuel plate 23 is fixed directly to the first wall 37 of the oil reservoir housing 19. More specifically, the support 24 of the fuel plate 23 is flanged to an interface formed on the first wall 37 of the oil reservoir housing 19.

[0063] The fuel circuit 20 also includes an independent piece of equipment 21, which is in this case a fuel / oil heat exchanger. The equipment 21 is directly fixed to the second wall 38 of the casing 19 of the oil reservoir 18. More precisely, the equipment 21 is clamped onto an interface formed on the second wall 38 of the casing 19 of the oil reservoir 18.

[0064] The various components (fuel tank, fuel pump 25, fuel plate 23, independent equipment 21, etc.) of the fuel circuit 20 are connected to each other via various fuel lines. The support 24 of the fuel plate 23 may include one or more internal fuel lines to create one or more additional heat exchanges between the fuel circuit 20 and the oil circuit 17. One or more fuel lines may pass through the oil tank 18 to create one or more additional heat exchanges between the fuel circuit 20 and the oil circuit 17.

[0065] The various components (oil tank 18, lubrication unit 26, equipment 35, etc.) of the oil circuit 17 are connected to each other via various oil lines. One or more oil lines may pass through the fuel tank, to create one or more additional heat exchanges between the fuel circuit 20 and the oil circuit 17.

Claims

Demands

1. Assembly (12) for an aircraft (2) turbomachine (1) comprising: - a housing (14) including a casing (15) and gears (16a-16d), the gears (16a-16d) being arranged inside the casing (15) and meshed with each other; - an oil circuit (17) including an oil reservoir (18), the oil reservoir (18) including a casing (19) which is integral with the casing (15) of the housing (14); - a fuel circuit (20) including at least one piece of equipment (21, 22a-22d); characterized in that the equipment (21a, 22a-22d) of the fuel circuit (20) is fixed on the oil tank (18), to allow heat exchange between the fuel circuit (20) and the oil circuit (17).

2. Assembly (12) according to claim 1, characterized in that the equipment (21) of the fuel circuit (20) is fixed directly on the casing (19) of the oil tank (18).

3. Assembly (12) according to claim 1, characterized in that the equipment (22a-22d) of the fuel circuit (20) is part of a fuel plate (23) which includes a support (24) on which the equipment (22a-22d) is fixed, the support (24) being fixed to the casing (19) of the oil tank (18).

4. Assembly (12) according to the preceding claim, characterized in that the support (24) of the fuel plate (23) comprises at least one internal fuel channel.

5. Assembly (12) according to any one of claims 3 or 4, characterized in that the support (24) comprises fins placed inside the oil reservoir (18).

6. Assembly (12) according to any one of the preceding claims, characterized in that the fuel circuit (20) comprises at least one fuel line which passes through the oil reservoir (18).

7. Assembly (12) according to any one of the preceding claims, characterized in that the oil circuit (17) comprises at least one oil line which passes through a fuel tank.

8. Assembly (12) according to any one of the preceding claims, characterized in that the fuel circuit (20) comprises a fuel pump (25) which is externally mounted on the crankcase (15) of the housing (14), the fuel pump (25) being driven in rotation by one of the toothed wheels (16a-16d).

9. Assembly (12) according to any one of the preceding claims, characterized in that the oil circuit (17) comprises a lubrication unit (26) which is externally reported on the housing (15) of the casing (14), the lubrication unit (26) comprising an oil supply pump and an oil recovery pump which are driven in rotation by one of the gear wheels (16a-16d).

10. Aircraft turbomachine (1) (2) comprising an assembly (12) according to any one of the preceding claims.

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