Aircraft propulsion system comprising two separate oil circuits

Abstract

Aircraft propulsion assembly comprising a propulsion module having a fan and a rectifier; a gas generator (30); a speed reduction device (40) configured to drive the fan shaft at a rotational speed lower than the rotational speed of the gas generator drive shaft (30); a variable pitch device (50) configured to adjust the pitch of the fan blades and / or the rectifier blades; and an oil supply device (60) having a first oil circuit (60A) configured to supply oil to the gas generator (30), and a second oil circuit (60B) configured to supply oil to the speed reduction device (40) and the variable pitch device (50). Figure for the abstract: Fig. 3.

Description

Title of the invention: Aircraft propulsion system comprising two separate oil circuits. Technical field

[0001] The present description relates to an aircraft propulsion assembly comprising an oil supply device having two separate oil circuits.

[0002] In the present description, the term "aircraft propulsion unit" refers to the set of turbomachines or gas turbine devices producing thrust necessary for the propulsion of an aircraft, in particular an airplane, by reaction to the high-speed ejection of gas producing motive energy, and equipped with a nacelle or not. Previous technique

[0003] Much research is focused on improving the efficiency of aeronautical engines, particularly aircraft engines, in order to reduce their environmental impact. One of the identified approaches for improving the propulsive efficiency of aircraft engines, reducing their fuel consumption, and the noise generated by the propulsion module is to increase the bypass ratio (BPR) as much as possible. The bypass ratio is the ratio of the mass flow rate of the secondary airflow to the mass flow rate of the primary airflow. One solution to achieve this is to indirectly couple the propulsion module and the gas generator, for example, via a speed reduction device. This allows for the independent optimization of the rotational speed of the moving parts of the gas generator and the rotational speed of the propulsion module's rotor.To further optimize performance, one solution is to equip the propulsion module with a variable pitch device to adjust the pitch of the fan blades and / or the stator blades according to the flight phases and / or engine speed.

[0004] However, adding devices such as the speed reduction device and the variable valve timing device, each with its own requirements, particularly in terms of lubrication (for the speed reduction device) and actuation (for the variable valve timing device), greatly complicates the oil supply system for the propulsion assembly. This raises issues in terms of inherent complexity, mass, size, and maintenance. Therefore, there is a need for this. Description of the invention

[0005] One embodiment relates to an aircraft propulsion assembly comprising a propulsion module having a fan equipped with fan blades and a stator equipped with stator blades, and a fan shaft configured to drive the fan in rotation; a gas generator having a drive shaft; a speed reduction device coupling the drive shaft and the fan shaft in rotation, and configured to drive the fan shaft at a rotational speed lower than the rotational speed of the drive shaft; a variable pitch device configured to adjust the pitch of the fan blades and / or the stator blades;and an oil supply device having a first oil circuit configured to supply the gas generator with oil for the lubrication of the gas generator, and a second oil circuit, separate from the first oil circuit, configured to supply the speed reduction device with oil for the lubrication of the speed reduction device and the variable timing device with oil for the actuation of the variable timing device.

[0006] In the following and unless otherwise indicated, "propulsion assembly" means "aircraft propulsion assembly".

[0007] The propulsion module may be enclosed or unenclosed. A stator is a stationary impeller rotating around the axis of the propulsion assembly (i.e., the stator is a stator), while the fan is a rotating impeller rotating around the axis of the propulsion assembly (i.e., the fan is a rotor). The stator, generally located downstream of the fan, straightens the airflow downstream of the fan along the axis of the propulsion assembly.

[0008] As a reminder, the pitch or pitch angle of a blade corresponds to the angle formed by a chord of the blade, the chord being an abstract geometric segment extending, at a given height of the airfoil, between the leading edge and the trailing edge of the blade, with the axis of the wheel, namely the fan or the stator in which the blade is mounted. A variable pitch device is a device configured to adjust the pitch of all the blades of the same wheel (all the blades of the wheel having the same pitch at a given instant), for example, according to the operating conditions of the propulsion system or the flight phase of the aircraft on which the propulsion system is mounted. Hereinafter, and unless otherwise specified, "pitch device" means "variable pitch device".

[0009] The gas generator can be a single, double or triple body gas generator, and comprises from upstream to downstream (according to the direction of gas flow within the gas generator), along the axis, a compressor (or compressor section), a combustion chamber, and a turbine (or turbine section).

[0010] A speed reduction device is a device configured to couple in rotation a drive shaft of a gas generator, for example a shaft of A low-pressure unit is defined as a propulsion assembly comprising a low-pressure unit and a high-pressure unit, with a fan shaft, shrouded or unshrouded, and configured to drive the fan shaft at a rotational speed lower than the rotational speed of the drive shaft. In the following sections, and unless otherwise specified, "reduction device" means "speed reduction device".

[0011] For example, the speed reduction device may be an epicyclic gear train reduction device, for example of the "epicyclic" or "planetary" type, according to the terminology sometimes used by those skilled in the art. Such a device may comprise one stage, two stages, or more than two stages.

[0012] According to a first embodiment, the reduction device may be of the planetary or "star" type and include a sun pinion, which forms the input of the reduction device. The axis of rotation of the sun pinion forms the axis of rotation of the reduction device and may coincide with the axis of the propulsion assembly. The sun pinion is configured to be driven in rotation by a drive shaft. The ring gear forms the output of the reduction device. The ring gear is coaxial with the sun pinion and configured to drive a blower shaft in rotation around the axis. Several satellites, or satellite pinions, may be distributed circumferentially around the axis between the sun pinion and the ring gear. Each satellite gear is meshed with the sun pinion and with the ring gear.The satellites are mounted on a satellite carrier which is configured to be fixed relative to a stator part of a propulsion assembly, for example relative to an upstream compressor casing.

[0013] According to a second variant, the reduction device may be of the epicyclic or "planetary" type. In this case, compared to the planetary type according to the first variant, the ring gear is configured to be fixedly mounted on a stator portion of the propulsion assembly, and the fan shaft is driven in rotation by the planet carrier (which is therefore rotatable relative to the stator portion of the propulsion assembly, for example, relative to an upstream compressor housing). The stator portions of the first and second variants may correspond to different parts of the same element, or to distinct elements.

[0014] Regardless of the configuration of the reduction device, the diameter of the ring gear is greater than the diameter of the satellite carrier, which is itself greater than the diameter of the solar pinion. The satellites are radially arranged between the solar pinion and the ring gear, and the output rotational speed is less than the input rotational speed.

[0015] The reduction ratio of the reduction device can be greater than or equal to 2.5 and less than or equal to 14.0.

[0016] The oil supply device may comprise only the first oil circuit and the second oil circuit. For example, the propulsion assembly does not include No oil circuits other than those of the oil supply system. Hereafter, and unless otherwise specified, "first circuit" and "second circuit" refer to "first oil circuit" and "second oil circuit," respectively. The first and second circuits may each be closed circuits. The first and second circuits are distinct from one another. In other words, the first and second circuits have no common components, or only one component that maintains the fluid separation of each circuit (for example, if both circuits flow in parallel through the same heat exchanger).

[0017] The first circuit is configured to supply the gas generator with oil for the lubrication and cooling of the gas generator, for example, for the lubrication and cooling of the bearings, bushings, and / or gears (for example, high-pressure and / or low-pressure shaft bearings in the case of a twin-spool gas generator, gears within the accessory drive train or ADT). Such an oil supply is also known to those skilled in the art as "engine chamber lubrication."

[0018] The second circuit is configured to supply, on the one hand, the speed reduction device with oil for lubricating and cooling the speed reduction device, and on the other hand, the variable timing device with oil for actuation. For example, the second circuit can supply oil for lubricating and cooling the various moving parts of the reduction device (e.g., the speed reduction mechanism), such as the gear teeth and bearings of the various gears and rotating elements. The second circuit can directly supply lubricating oil to the gear teeth and bearings. For example, the second circuit can supply oil for actuation of one or more control cylinders of the timing device.This control oil can also be used to lubricate the moving parts of the timing device, but not necessarily.

[0019] The natural tendency for a person skilled in aircraft propulsion systems is to design an integrated oil supply system, for example, by providing a single oil circuit, with the assumption that such a structure would optimize complexity, size, weight, and maintenance requirements. However, the inventors have demonstrated that the structure, counterintuitive to a person skilled in the art, with two separate oil supply circuits as described herein, offers relative simplicity and a relatively small footprint, which facilitates its integration within the propulsion system, while the overall weight of such an oil supply system can be controlled and this structure allows the use of relatively standard components, thus providing a certain level of reliability and reduced maintenance requirements.

[0020] In some embodiments, the first oil circuit includes a first filter configured to filter first particles and the second oil circuit includes a second filter configured to filter second particles, the second particles being smaller than the first particles.

[0021] In other words, the first filter allows for less fine filtering than the second filter, or conversely, the second filter allows for finer filtering than the first filter. The first and second filters can each comprise one or more filters.

[0022] Such a configuration allows for optimal adaptation of the oil filtration within each circuit, according to the needs of the gas generator on the one hand, and the timing and reduction devices on the other. This can contribute to a certain simplicity and a relatively small footprint, facilitating the installation of the oil supply system, as well as a relatively controlled weight, a certain reliability, and reduced maintenance requirements.

[0023] In some embodiments, the first oil circuit is configured to supply the gas generator with oil at a temperature less than or equal to a first temperature and the second oil circuit is configured to supply the speed reduction device at a temperature less than or equal to a second temperature, the first temperature being (strictly) greater than the second temperature.

[0024] In some embodiments, the first oil circuit is configured to supply the gas generator with oil at a temperature less than or equal to a first temperature and the second oil circuit is configured to supply the variable timing device at a temperature less than or equal to a third temperature, the first temperature being (strictly) less than the third temperature.

[0025] The first, second and third temperatures can be adjusted by providing various heat exchangers within the first and second circuits.

[0026] The difference between the third temperature and the first temperature can be quite small, for example on the order of 10% (ten percent).

[0027] In general, the presence of two separate oil circuits allows decoupling leading to a reduction in the mass and size of the assembly, and in particular of the heat exchangers, because the limit oil temperatures of each component can be adapted according to the elements to be supplied with oil.

[0028] Such first, second and / or third temperatures can contribute to providing a certain simplicity and a relatively small footprint facilitating the implementation of the oil supply system, as well as a relatively controlled mass, a certain reliability and reduced maintenance requirements.

[0029] In some embodiments, the first oil circuit includes a first supply configured to supply the gas generator with oil at a flow rate between 100 l / h (one hundred liters per hour) and 10,000 l / h (ten thousand liters per hour), and the second oil circuit includes a second supply configured to supply the speed reduction device with oil at a flow rate between 100 l / h (one hundred liters per hour) and 8,000 l / h (eight thousand liters per hour) and a third supply configured to supply the variable timing device with oil at a flow rate between 0 l / h (zero liters per hour) and 22,000 l / h (twenty-two thousand liters per hour).

[0030] Each supply may include a pump and / or a regulating device such as, for example, an oil metering device. The supplies may be located upstream of the gas generator, the reduction device, and / or the timing device, respectively. Each circuit may include other pumps, for example, recirculation pumps, located downstream of the gas generator, the reduction device, and / or the timing device, respectively. For the purposes of this description, and unless otherwise specified, the upstream and downstream sections within the first and second circuits are to be considered according to the direction of oil flow within each circuit, with the oil flowing from upstream to downstream.

[0031] Such first, second and third feeds can contribute to providing a certain simplicity and a relatively small footprint facilitating the installation of the oil supply device, as well as a relatively controlled mass, a certain reliability and reduced maintenance requirements.

[0032] In some embodiments, the second oil circuit includes a first loop configured to supply the speed reduction device and a second loop configured to supply the variable timing device, the second loop being in bypass of the first loop.

[0033] The first loop can be a closed loop. The second loop can form a closed loop with a first portion of the first loop extending downstream of an outlet point of the second loop and upstream of an inlet point of the second loop. In other words, the second loop forms a fluid passage extending parallel to a second portion of the first loop extending downstream of the inlet point of the second loop and upstream of the outlet point of the second loop.

[0034] Each loop can be configured to supply the timing device and the reduction device with a shared common oil, but according to the specific needs of each of these two devices. This can contribute to providing a certain simplicity and a relatively small footprint, facilitating installation. of the oil supply system, as well as a relatively controlled mass, a certain reliability and reduced maintenance requirements.

[0035] In some embodiments, the second supply includes a feed pump and a metering device arranged within the first loop and the third supply includes a feed pump arranged within the second loop.

[0036] The lift pump can be a pump which, during the operation of the propulsion system, runs continuously at a speed ensuring a continuous supply of oil downstream of the lift pump, regardless of the instantaneous oil requirements. The lift pump can be continuously driven by the accessory gearbox (AGB), and therefore by the high-pressure shaft. The metering device can be a device that allows the desired instantaneous oil flow rate to be transferred to a downstream device, in this example the reduction device, and redirects the excess oil supplied by the lift pump upstream of the lift pump and downstream of the reduction device, for example into an oil reservoir. The lift pump can also supply oil to the feed pump. According to this latter variant, the lift pump can be considered part of both the secondary and tertiary oil supply.

[0037] Such a configuration of the second and third supply can contribute to providing a certain simplicity and a relatively small footprint facilitating the installation of the oil supply device, as well as a relatively controlled mass, a certain reliability and reduced maintenance requirements.

[0038] In some embodiments, the speed reduction device comprises a housing containing a speed reduction mechanism, the second loop comprising an inlet branch disposed within the first loop upstream of the speed reduction device and an outlet branch opening into the housing of the speed reduction device.

[0039] Such a configuration allows for the sharing of components between the first and second loops, such as a recirculation pump and an oil reservoir, while ensuring a supply according to the specific needs of each of the timing and reduction devices. The oil from the second loop, downstream of the timing device, can be recovered along with the oil downstream of the reduction device, both within and at the fluid outlet of the reduction device's housing.

[0040] Such a configuration of the connections can contribute to providing a certain simplicity and a relatively small footprint facilitating the installation of the oil supply device, as well as a relatively controlled mass, a certain reliability and reduced maintenance requirements.

[0041] In some embodiments, the inlet connection is located downstream of the fuel pump and upstream of the metering device.

[0042] The lift pump can thus supply the metering unit in the first loop to provide the reduction device, and the feed pump in the second loop to supply the timing device. Such a shared system can contribute to a certain simplicity and a relatively small footprint, facilitating the installation of the oil supply system, as well as a relatively controlled weight, a certain reliability, and reduced maintenance requirements.

[0043] In some embodiments, the first loop has an oil / air heat exchanger downstream of the inlet fitting of the second loop and upstream of the speed reduction device, and an oil / fuel heat exchanger downstream of the speed reduction device and upstream of the inlet fitting of the second loop.

[0044] For example, the second loop does not have a heat exchanger. For example, the second circuit includes only the oil / air heat exchanger and the oil / fuel heat exchanger. The oil / fuel heat exchanger is shared by the first and second loops, while the oil / air heat exchanger regulates the oil temperature of the first loop only, upstream of the reduction device.

[0045] Such a configuration allows the oil temperature to be adjusted to supply the reduction device on the one hand and the timing device on the other, according to the specific needs of each of these two devices, while sharing as many components as possible, in this case the oil / fuel heat exchanger. This can contribute to a certain simplicity and a relatively small footprint, facilitating the installation of the oil supply device, as well as a relatively controlled weight, a certain reliability, and reduced maintenance requirements. Brief description of the drawings

[0046] The purpose of this presentation and its advantages will be better understood upon reading the detailed description below of various embodiments given by way of non-limiting examples. This description refers to the attached figure pages, on which:

[0047] [Fig-1] Fig. 1 represents an aircraft equipped with a propulsion system for aircraft,

[0048] [Fig.2] Fig.2 schematically represents the aircraft propulsion system of Fig.1, and

[0049] [Fig.3] The [Fig.3] schematically represents the oil supply device of the aircraft propulsion assembly of the [Fig.1]. Description of the implementation methods

[0050] Figure 1 represents an aircraft 100, in this example an airplane, equipped with two aircraft propulsion systems 10, in this example two unducted turbofan engines 10, namely one propulsion system 10 per wing 101, with only one propulsion system 10 and one wing 101 being shown in Figure 1. According to one embodiment, the aircraft 100 can be equipped with more than one propulsion system 10 per wing 101, each wing 101 being provided with the same number of propulsion systems 10.

[0051] Figure 2 shows a schematic cross-sectional view of the propulsion assembly 10, according to plane II of Figure 1. The propulsion assembly 10 extends along an axis X and comprises a propulsion module 20, a gas generator 30, a speed reduction device 40, a variable pitch device 50, and an oil supply device 60.

[0052] The propulsion module 20 has a fan 22 equipped with a plurality of fan blades 22A and a rectifier 24 equipped with a plurality of rectifier blades 24A, and a fan shaft 26 configured to drive the fan 22 in rotation. The fan shaft 26 can extend along the X-axis.

[0053] The gas generator 30 has a drive shaft 33A. The drive shaft 33A can extend along the X axis. The blower shaft 26 can be coaxial with the drive shaft 33A, and their respective axis of rotation can coincide with the X axis of the propulsion assembly 10. In this example, the gas generator 30 comprises, from upstream to downstream in the direction of gas flow within the propulsion assembly 10, a compressor 32 (or compressor section 32), a combustion chamber 34, and a turbine 36 (or turbine section 36).

[0054] The gas generator 30 may be of the twin-spool type and comprise a low-pressure spool 30A and a high-pressure spool 30B. The low-pressure spool 30A may comprise a low-pressure compressor 32A rotationally coupled to a low-pressure turbine 36A via a low-pressure shaft 33A, which may form the drive shaft of the gas generator 30. The high-pressure spool 30B may comprise a high-pressure compressor 32B located downstream of the low-pressure compressor 32A and upstream of the combustion chamber 34, and a high-pressure turbine 36B located downstream of the combustion chamber 34 and upstream of the low-pressure turbine 36A, and rotationally coupled to the high-pressure compressor 32B via a high-pressure shaft 33B. The compressor 32 of the gas generator 30 may comprise the low-pressure and high-pressure compressors 32A and 32B.The turbine 36 of the gas generator 30 can comprise the low-pressure and high-pressure turbines 36A and 36B. The low-pressure and high-pressure shafts 33A and 33B can be coaxial. The high-pressure shaft 33B can receive a portion of the low-pressure shaft 33A. The... [Fig.2] is schematic, each compressor and each turbine being able to have one or more stages, each stage comprising a rotor (or moving wheel) and a stator or rectifier (or fixed wheel).

[0055] The speed reduction device 40 is configured to rotationally couple the drive shaft 33A with the blower shaft 26. The speed reduction device 40 is configured to drive the blower shaft 26 at a rotational speed lower than the rotational speed of the drive shaft 33A. In this example, the drive shaft 33A connects the low-pressure turbine 36A (or the low-pressure housing 30A) to an inlet of the speed reduction device 40, while the blower shaft 26 connects an outlet of the speed reduction device 40 to the blower 22. The speed reduction device 40 has a housing 40B containing a speed reduction mechanism 40A.

[0056] The variable pitch device 50 is configured to adjust the pitch of the fan blades 22A and / or the rectifier blades 24A. In this example, the pitch device 50 allows adjustment of the pitch of the fan blades 22A, while the rectifier blades 24A have a fixed pitch. According to an alternative (not shown), the fan blades 22A may have a fixed pitch, while the pitch device 50 allows adjustment of the pitch of the rectifier blades 24A. According to yet another alternative (not shown), the pitch device 50 allows adjustment of both the pitch of the fan blades 22A and the pitch of the rectifier blades 24A. The 50 levelling device may include one or more cylinders not shown in [Fig.2] (see 50C in [Fig.3]), these cylinders being single or double chamber.These cylinders can be operated by oil pressure, allowing the timing of the blower blades 22A and / or the stator blades 24A to be adjusted via a linkage and connecting rod system (not shown) but well known to those skilled in the art. The timing device 50 can, for example, be housed within the enclosure 40B which contains the speed reduction mechanism 40A.

[0057] The oil supply device 60, shown very schematically in [Fig.2], is configured to supply the gas generator 30 with oil for the lubrication of the gas generator 30, the speed reduction device 40 with oil for the lubrication of the speed reduction device 40 and the variable timing device 50 with oil for the actuation of the variable timing device 50.

[0058] The oil supply device 60 is described in more detail with reference to [Fig. 3]. The oil supply device 60 has a first oil circuit 60A configured to supply the gas generator 30 with oil for the lubrication of the gas generator 30, and a second oil circuit 60B, separate from the first oil circuit 60A, configured to supply the reduction device. Speed ​​40 is lubricated with oil for the speed reduction device 40 and the variable timing device 50, and oil is used to actuate the variable timing device. The first and second circuits, 60A and 60B, are each closed circuits in this example.

[0059] In this example, the first circuit 60A has a single loop B0, while the second circuit 60B comprises a first loop B1 configured to supply the speed reduction device 40 and a second loop B2 configured to supply the variable timing device 50, the second loop B2 being in parallel with the first loop B1. The loop B0 of the first circuit 60A is a closed loop. The first loop B1 of the second circuit 60B is a closed loop. The second loop B2 forms a closed loop with a first portion B1A of the first loop B1, which extends downstream of an output tap PS of the second loop B2 and upstream of an input tap PE of the second loop B2. In other words, the second loop B2 forms a fluidic passage which extends in parallel with a second portion B1B of the first loop Bl which extends downstream of the PE inlet tap of the second loop B2 and upstream of the PS outlet tap of the second loop B2.For example, the PE inlet branch of the second loop B2 can be located within the first loop Bl upstream of the speed reduction device 40 and the PS outlet branch of the second loop B2 can open into the enclosure 40B of the speed reduction device 40.

[0060] In [Fig. 3], the arrows on the first and second circuits 60A and 60B indicate the direction of oil flow within each of these circuits. Hereafter, and unless otherwise specified, upstream and downstream within these circuits refer to the direction of oil flow, with the oil flowing from upstream to downstream.

[0061] In this example, the first oil circuit 60A includes a first filter 60A1 configured to filter first particles, and the second oil circuit 60B includes a second filter 60B1 configured to filter second particles, the second particles being smaller than the first particles. In this example, the second circuit 60B includes a third filter 60B11 immediately upstream of the timing device 50, for example, within the second loop B2. The first filter 60B1 is, in this example, located within the first portion B1A of the first loop BL.

[0062] In this example, the first circuit 60A is configured to supply the gas generator 30 with oil at a temperature less than or equal to a first temperature T1, and the second oil circuit 60B is configured to supply the speed reduction device 40 at a temperature less than or equal to a second temperature T2, the first temperature T1 being greater than the second temperature T2. The second oil circuit 60 is also configured in this example to supply the variable calibration device 50 at a temperature less than or equal to a third temperature T3, the first temperature T1 being less than the third temperature T3.

[0063] In this example, to regulate the oil temperature at the inlet of the gas generator 30, the first circuit 60A may include an oil / air heat exchanger 60A2 immediately upstream of the gas generator 30, and an oil / fuel heat exchanger 60A3 downstream of the gas generator 30. In this example, to regulate the oil temperature at the inlet of the speed reducer 40 and the timing device 50, the first loop B1 has an oil / air heat exchanger 60B2 downstream of the inlet PE branch of the second loop B2 and upstream of the speed reduction device 40, and an oil / fuel heat exchanger 60B3 downstream of the speed reduction device 40 (and the outlet PS branch) and upstream of the inlet PE branch of the second loop B2. In this example, the oil / fuel heat exchangers 60A3 and 60B3 of the first and second circuits 60A and 60B, respectively, are separate heat exchangers.According to one variant, shown in dashed line on [Fig.3], the oil / fuel heat exchangers 60A3 and 60B3 can be formed by a single heat exchanger with three separate flows, namely two oil flows and a single fuel flow.

[0064] In this example, the first oil circuit 60A includes a first supply 60A4 configured to supply the gas generator 30 with oil at a flow rate between 100 l / h and 10,000 l / h, and the second oil circuit 60B includes a second supply 60B4 configured to supply the speed reduction device 40 with oil at a flow rate between 100 l / h and 8,000 l / h and a third supply 60B5 configured to supply the variable timing device 50 with oil at a flow rate between 0 l / h and 22,000 l / h.

[0065] In this example, the first supply includes a supply pump 60A4, for example a positive displacement pump configured to deliver a flow rate proportional to the rotational speed of the high-pressure body 30B of the gas generator 30, for example via an accessory gearbox (not shown) of the propulsion assembly 10, or via an electric drive (not shown). In this example, the first circuit 60A includes, downstream of the gas generator 30, a recirculation pump 60A5. The first circuit 60A includes an oil reservoir 60A6.

[0066] In this example, the second supply 60B4 comprises a feed pump 60B41 and a metering unit 60B42 located within the first loop B1, and the third supply 60B5 comprises a feed pump 60B5 located within the second loop B2. The inlet PE connection is located downstream of the feed pump 60B41 and upstream of the metering unit 60B42. The feed pump 60B41 is, for example, a positive displacement pump. The inlet PE connection is located downstream of the pump The third supply pump 60B41 is located upstream of the feed pump 60B42. The third supply pump 60B5 is positioned downstream of the feed pump 60B41, and the feed pump 60B41 can be sized to meet the oil requirements during all phases of flight of the aircraft 100, including both the reduction gear 40 and the stabilization device 50. In this example, the second circuit 60B includes, downstream of the reduction gear 40 and the stabilization device 50, a recirculation pump 60B6, which may be a positive displacement pump. For example, the flow rate of the recirculation pump 60B6 may be the same as the flow rate of the feed pump 60B41, but not necessarily. The second circuit 60B includes an oil reservoir 60B7.An oil return line 60B8 extends from the metering unit 60B42 directly to the reservoir 60B7, to redirect excess feed oil from the feed pump 60B41, which would not be needed for the immediate lubrication of the gas generator 30, to the reservoir 60B7. The metering unit 60B42 can be controlled by the full authority digital engine control unit (not shown) 10, also known as FADEC.

[0067] In this example, the first circuit 60A comprises successively from upstream to downstream, in the direction of the oil circulation, in a closed loop: the oil tank 60A6, the first supply / supply pump 60A4, the first filter 60A1, the oil / air heat exchanger 60A2, the gas generator 30, the recirculation pump 60A5, the oil / fuel heat exchanger 60A3, and again the oil tank 60A6, etc.

[0068] For example, within the gas generator 30, the lubricating oil supplied by the first circuit 60A is distributed between the different bearings, or more generally between the different engine enclosures, by a pressure balance which is linked to the permeability of the different oil jets.

[0069] In this example, the first loop B1 of the second circuit 60B includes successively from upstream to downstream in the direction of oil circulation, in a closed loop, the reservoir 60B7, the lift pump 60B41, the first filter 60B1, the PE inlet of the second loop B2, the metering device 60B42, the oil / air heat exchanger 60B2, the reduction device 40, the PS outlet of the second loop B2 (in this example included in the enclosure 40B of the reduction device 40), the recirculation pump 60B6, the oil / fuel heat exchanger 60B3, and again the oil reservoir 60B7, etc. The first section B1A of the first loop B1 comprises, successively from upstream to downstream in the direction of oil flow, the outlet PS branch of the second loop B2, the recirculation pump 60B6, the oil / fuel heat exchanger 60B3, the oil reservoir 60B7, the lift pump 60B41, the first filter 60B1, the inlet PE branch of The second loop B2. The second section B1B of the first loop B1 comprises, successively from upstream to downstream in the direction of oil flow, the PE inlet of the second loop B2, the metering unit 60B42, the oil / air heat exchanger 60B2, the reduction device 40, and the PS outlet of the second loop B2. The second loop B2 comprises, successively from upstream to downstream in the direction of oil flow, the PE inlet of the second loop B2, the third feed / supply pump 60B5, the third filter 60B11, the shimming device 50, and the PS outlet of the second loop B2. Since the PE and PS inlet and outlet points are "fluidic nodes," they can be considered to belong to each of the first section B1A, the second section B1B, and the second loop B2.

[0070] The presence of the oil / fuel heat exchangers 60A3 and 60B3 immediately upstream of the tanks 60A6 and 60B7, respectively, allows, on the one hand, for the fuel to be heated via the oil under cold conditions, the oil being relatively hot downstream of the gas generator 30 on the one hand and of the reduction devices 40 and timing devices 50 on the other. This also allows the oil to be cooled before being returned to the gas generator 30 on the one hand and the reduction devices 40 and timing devices 50 on the other, and also allows the tanks 60A6 and 60B7 to be considered "warm".

[0071] For example, within the reduction device 40, the lubricating oil supplied by the second circuit 60B is distributed to the various gears 40A1 and the various bearings 40A2 of the reduction mechanism 40A, as well as within the enclosure 40B.

[0072] For example, within the shim device 50, the actuating oil supplied by the second circuit 60B feeds a power control unit 50A (or PCU), which distributes and recovers the oil to / from an oil transfer bearing 50B (or OTB), which itself distributes and recovers the oil to / from one or more cylinders 50C. Any other shim device 50 structure is conceivable.

[0073] In operation, the oil supply device 60 operates via the first circuit 60A and via the second circuit 60B, the two circuits 60A and 60B operating simultaneously in parallel and independently of each other. The oil within each circuit may be identical or different.

[0074] During operation, in the first circuit 60A, oil is pumped from reservoir 60A6 by pump 60A4. The oil is then filtered as it passes through the first filter 60A1. The oil is then cooled by the heat exchanger 60A2 to ensure that the supply temperature to the gas generator 30 remains below or equal to the first temperature TL. The oil then enters the gas generator 30, in the various engine compartments, for lubrication of the gas generator 30. At the outlet of the gas generator 30, the oil is recovered by the recirculation pump 60A5, which returns the oil directly to reservoir 60A6 via the heat exchanger 60A3.

[0075] During operation, in the second circuit 60B, oil is pumped from the reservoir 60B7 by the lift pump 60B41. The oil is then filtered as it passes through the second filter 60B1. The oil then follows two different paths. A portion of the oil is pumped by the supply pump 60B5 into the second loop B2 via the inlet port PE, then undergoes a second filtration via the filter 60B11 before supplying the timing device 50, and finally returning to the first loop B1 via the outlet port PS. The portion of oil not pumped by the supply pump 60B5 remains in the first loop B1 and flows to the metering unit 60B42. The metering unit 60B2 regulates the flow of oil sent to the reduction device 40, via the exchanger 60B2, the excess oil being returned directly to the reservoir 60B7 via the line 60B8.The oil is then cooled by the heat exchanger 60B2 to ensure that the supply temperature to the reduction device 40 remains below or equal to the second temperature T2. At the outlet of the reduction device 40, the oil from both the reduction device 40 and the timing device 50 is recovered by the recirculation pump 60B6, which returns the oil directly to the reservoir 60B7 via the heat exchanger 60B3. The heat exchanger 60B3 ensures that the oil temperature downstream, up to the timing device, remains below or equal to the third temperature T3.

[0076] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

[0077] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. Aircraft propulsion assembly (10) comprising: - a propulsion module (20) having a fan (22) equipped with fan blades (22A) and a stator (24) equipped with stator blades (24A), and a fan shaft (26) configured to drive the fan (22) in rotation, - a gas generator (30) having a drive shaft (33A), - a speed reduction device (40) rotationally coupling the drive shaft (33A) and the fan shaft (26), and configured to drive the fan shaft (26) at a rotational speed lower than the rotational speed of the drive shaft (33A), - a variable pitch device (50) configured to adjust the pitch of the fan blades (22A) and / or the stator blades (24A), and - an oil supply device (60) having a first oil circuit (60A) configured to supply the gas generator (30) with oil for the lubrication of the gas generator (30),and a second oil circuit (60B), separate from the first oil circuit (60A), configured to supply the speed reduction device (40) with oil for lubricating the speed reduction device (40) and the variable timing device (50) with oil for actuation of the variable timing device (50).

2. Aircraft propulsion assembly (10) according to claim 1, wherein the first oil circuit (60A) includes a first filter (60A1) configured to filter first particles and the second oil circuit (60B) includes a second filter (60B1) configured to filter second particles, the second particles being smaller than the first particles.

3. Aircraft propulsion assembly (10) according to claim 1 or 2, wherein the first oil circuit (60A) is configured to supply the gas generator (30) with oil at a temperature less than or equal to a first temperature and the second oil circuit (60B) is configured to supply the speed reduction device (40) at a temperature less than or equal to a second temperature, the first temperature being greater than the second temperature.

4. Aircraft propulsion assembly (10) according to any one of claims 1 to 3, wherein the first oil circuit (60A) is configured to supply the gas generator (30) with oil at a temperature less than or equal to a first temperature and the second oil circuit (60B) is configured to supply the variable pitch device (50) at a temperature less than or equal to a third temperature, the first temperature being less than the third temperature.

5. Aircraft propulsion assembly (10) according to any one of claims 1 to 4, wherein the first oil circuit (60A) comprises a first supply (60A4) configured to supply the gas generator (30) with oil at a flow rate between 100 l / h and 10,000 l / h, and the second oil circuit (60B) comprises a second supply (60B4) configured to supply the speed reduction device (40) with oil at a flow rate between 100 l / h and 8,000 l / h and a third supply (60B5) configured to supply the variable pitch device (50) with oil at a flow rate between 0 l / h and 22,000 l / h.

6. Aircraft propulsion assembly (10) according to any one of claims 1 to 5, wherein the second oil circuit (60B) comprises a first loop (B1) configured to supply the speed reduction device (40) and a second loop (B2) configured to supply the variable pitch device (50), the second loop (B2) being in bypass of the first loop (B1).

7. Aircraft propulsion assembly (10) according to claims 5 and 6, wherein the second supply (60B4) comprises a feed pump (60B41) and a metering device (60B42) arranged within the first loop (B1) and the third supply comprises a feed pump (60B5) arranged within the second loop (B2).

8. Aircraft propulsion assembly (10) according to claim 6 or 7, wherein the speed reduction device (40) comprises a housing (40B) containing a speed reduction mechanism (40A), the second loop (B2) comprising an inlet branch (PE) disposed within the first loop (Bl) upstream of the speed reduction device (40) and an outlet branch (PS) opening into the housing (40B) of the speed reduction device (40).

9. Aircraft propulsion assembly (10) according to claims 7 and 8, wherein the inlet nozzle (PE) is disposed downstream of the feed pump (60B41) and upstream of the metering device (60B42), the first loop (B1) having an oil / air heat exchanger (60B2) downstream of the inlet nozzle (PE) of the second loop (B2) and upstream of the speed reduction device (40), and an oil / fuel heat exchanger (60B7) downstream of the speed reduction device (40) and upstream of the inlet nozzle (PE) of the second loop (B2).

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