TURBOMACHINE INCLUDING A LUBRICATION UNIT AND A SPEED REDUCER

Abstract

The invention relates to a turbomachine (1) comprising: - a lubrication chamber (17) radially delimited by an annular inner shell (19) centered on the longitudinal axis (X), - an outer shell (18) arranged around the inner shell (19), - a storage arm (20) forming an auxiliary reservoir (20a) arranged at 6 o'clock and extending radially between the inner (19) and outer (18) shells, and having an internal cavity (200) opening into the chamber (17), - an oil recovery arm (21) for the lubrication chamber (17) extending radially between the shells (19, 18), and having an internal channel opening into the chamber (17), - an oil recovery scoop (22) for the chamber (17) configured to convey the oil from the chamber (17) to the recovery arm (21) and so as to limit the oil level in the enclosure (17) when the oil level in the internal cavity (220) has reached a predetermined threshold. Abbreviated figure: Figure 6

Description

Title of the invention: TURBOMACHINE COMPRISING A LUBRICATION UNIT AND A SPEED REDUCER Technical field of the invention

[0001] The invention relates to the field of turbomachinery for aircraft. More particularly, the invention relates to the field of turbomachinery comprising a fan driven in rotation by a fan shaft connected to a low-pressure shaft via a mechanical speed reducer. Technical background

[0002] An aircraft turbomachine, such as a turbojet, typically comprises, from upstream to downstream in the direction of gas flow, a movable fan rotating about a longitudinal axis, a low-pressure compressor and a high-pressure compressor, a combustion chamber, a high-pressure turbine and a low-pressure turbine and a gas exhaust nozzle.

[0003] The fan is driven in rotation by a fan shaft connected to the rotor of the low-pressure turbine, and allows the intake of an airflow that splits into a primary flow and a secondary flow. The primary flow passes through a primary channel of the turbomachine while the secondary flow is directed towards a secondary channel surrounding the primary channel.

[0004] The primary flow is compressed within the compressors. The compressed air is then mixed with a fuel and burned within the combustion chamber. The gases from the combustion pass through the turbines and then escape through the nozzle, the cross-section of which allows these gases to be accelerated to generate propulsion.

[0005] The low pressure turbine rotor is connected to the low pressure compressor rotor by a low pressure shaft and the high pressure turbine rotor is connected to the high pressure compressor rotor by a high pressure shaft.

[0006] Furthermore, in certain turbomachinery configurations, the fan shaft is connected to the low-pressure shaft by a speed reducer, which allows the fan to be driven at a rotational speed lower than that of the low-pressure shaft. To ensure lubrication of the speed reducer, the latter is typically arranged in a lubrication chamber. The lubrication chamber is radially delimited by an inner annular shell, which is surrounded by an outer annular shell. The inner and outer shells are connected by radial arms.

[0007] To ensure lubrication of the speed reducer in the lubrication chamber, the turbomachine further includes a main lubrication circuit for the reducer. The main circuit includes a main oil supply pump for the gearbox. The main pump is typically driven by the high-pressure shaft via an accessory gearbox.

[0008] During certain operating phases of the turbomachine, such as the free-rotating phases of the fan (known as "windmilling") during which the high-pressure shaft is barely rotated, the main pump is not primed and the main circuit does not lubricate the gearbox. In this context, the turbomachine includes an auxiliary lubrication circuit for the gearbox. The auxiliary circuit typically includes an auxiliary pump, for example, driven by the low-pressure shaft, or powered by an electric generator so that its rotational speed can be decoupled from the speed of the low-pressure or high-pressure shaft. The auxiliary pump draws oil from an auxiliary oil reservoir. The auxiliary circuit thus allows the gearbox to be lubricated by the auxiliary pump even when the fan is freely rotating.

[0009] Document FR-A1-3 108 951 describes a turbomachine comprising a lubrication chamber radially delimited by an inner shell which is surrounded by an outer shell. A speed reducer is arranged within the lubrication chamber.

[0010] According to this document, the turbomachine further comprises a main lubrication circuit for the gearbox and an auxiliary lubrication circuit for the gearbox, both connected to the lubrication chamber. The auxiliary circuit is connected to an auxiliary reservoir formed within a radial storage arm extending between the inner and outer shells. The storage arm is hollow and is positioned at the bottom of the chamber, i.e., at the 6 o'clock position, to collect the oil falling into the bottom of the chamber by gravity.

[0011] According to this document, the main circuit is also connected to a recovery arm adjacent to the storage arm. The oil flowing into the bottom of the lubrication chamber by gravity is conveyed to the recovery arm by overflow, that is, when the volume of oil in the lubrication chamber exceeds a certain volume, which is therefore greater than the volume of the auxiliary reservoir. The oil is then drawn from the recovery arm by a recovery pump from the main circuit.

[0012] Such a solution is not entirely satisfactory. Indeed, some components of the gearbox can become submerged in the stagnant oil within the lubrication chamber. As the gearbox has rotating parts, typically a ring gear, oil heating (generally called churning) can occur and damage the speed reducer.

[0013] There is therefore a need to provide a turbomachine which ensures efficient and reliable lubrication of the speed reducer. Summary of the invention

[0014] To this end, the invention proposes a turbomachine for an aircraft, extending around a longitudinal axis and comprising:

[0015] - a blower driven in rotation around the longitudinal axis by a shaft of blower,

[0016] - a low-pressure shaft connected to the blower shaft by a speed reducer mechanical,

[0017] - a lubrication chamber in which the speed reducer is arranged, the lubrication chamber being radially delimited by an internal annular ferrule centered on the longitudinal axis,

[0018] - an outer ferrule arranged coaxially around the inner ferrule,

[0019] - a storage arm arranged at 6 o'clock (six o'clock) and extending radially between the internal and external ferrules, the storage arm having an internal cavity opening into the lubrication chamber and forming an auxiliary oil reservoir intended to be connected to an auxiliary lubrication circuit of the speed reducer, and

[0020] - an oil recovery arm from the lubrication chamber extending dialement between the inner and outer shells and intended to be connected to a main lubrication circuit of the speed reducer, the recovery arm having an internal channel opening into the lubrication chamber.

[0021] The turbomachine is characterized in that the lubrication chamber further comprises:

[0022] - an oil recovery scoop for the configured lubrication chamber in order to convey the oil from the lubrication chamber to the recovery arm and in order to limit the oil level in the lubrication chamber when the oil level in the internal cavity has reached a predetermined threshold.

[0023] The lubrication chamber includes a storage arm having an internal cavity opening into the lubrication chamber and forming an auxiliary oil reservoir intended to be connected to an auxiliary lubrication circuit for the gearbox. The storage arm is located at the 6 o'clock position (six o'clock by analogy to the corresponding position on a clock face), that is, at the bottom of the chamber, at the lowest point of the lubrication chamber. The gearbox lubricating oil thus flows by gravity into the auxiliary reservoir. When the oil volume in the internal cavity of the auxiliary reservoir exceeds a certain threshold, in particular the maximum volume of the internal cavity, the oil accumulates in the lubrication chamber, and specifically at the bottom of the lubrication chamber. According to the invention, the lubrication chamber thus includes an oil recovery scoop for the lubrication chamber.This recovery scoop allows the oil to be conveyed from the lubrication chamber to the arm. recovery and limiting the oil level in the lubrication chamber.

[0024] Thanks to the invention, the oil level in the lubrication chamber is controlled by the recovery scoop and maintained at a predetermined level. Rotating parts of the gearbox are therefore no longer at risk of being submerged in the oil present in the lubrication chamber, thus limiting the risk of oil overheating. The oil circulating in the main circuit can therefore remain at a suitable temperature to dissipate heat from the gearbox.

[0025] The invention may comprise one or more of the following features, taken individually or in combination with each other:

[0026] - the recovery scoop extends circumferentially between the storage arm and the recovery arm;

[0027] - the recovery scoop is arranged inside the lubrication chamber and attached to the internal ferrule;

[0028] - the storage arm has a closed radially external end and a radially internal end having an opening, and the recovery scoop has an inlet arranged at the opening so that oil is transferred by overflow into the inlet when the volume of oil in the lubrication chamber exceeds a threshold;

[0029] - the speed reducer includes a solar element coupled in rotation with the lower shaft pressure, a crown extending around the longitudinal axis and coupled in rotation with the blower shaft, at least one satellite meshing with the crown and the solar and a fixed satellite carrier, the internal ferrule being arranged around the crown;

[0030] - the lubrication chamber includes an oil recovery gutter the lubrication chamber, this gutter being arranged in the inner ferrule and connected to the inner ferrule and comprising an annular body centered on the longitudinal axis and a trumpet having an inlet mouth formed in the body of the gutter and an oil ejection outlet towards the recovery scoop;

[0031] - the trumpet surmounts the storage arm;

[0032] - the proboscis is curved and extends radially outwards from the body;

[0033] - the ejection outlet section is between 20% and 80% of the section of the inlet of the recovery scoop;

[0034] - the cross-section of the inlet opening is greater than or equal to the cross-section of the outlet ejection; - The oil recovery scoop of the lubrication chamber is configured to convey oil from the lubrication chamber to the recovery arm when the oil level in the lubrication chamber, and in particular at the bottom of the chamber, has reached a predetermined threshold,

[0035] - the turbomachine includes a speed reducer lubrication system comprising a main lubrication circuit and an auxiliary lubrication circuit, the circuits being connected to the lubrication chamber. Brief description of the figures

[0036] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0037] [Fig. 1] is a schematic longitudinal cross-sectional representation of half an aircraft turbomachine according to the invention,

[0038] [Fig.2] is a schematic longitudinal sectional representation of a speed reducer equipping the turbomachine of [Fig.1],

[0039] [Fig.3] is a schematic view of a lubrication system for the reducer of [Fig.2], comprising an auxiliary circuit when stopped and a main circuit when running,

[0040] [Fig.4] is a schematic view of a lubrication system for the reducer of [Fig.2], comprising an auxiliary circuit in operation and a main circuit in operation,

[0041] [Fig.5] is a cross-sectional view of a lubrication chamber equipping the turbomachine of [Fig.1],

[0042] [Fig.6] is an enlarged perspective view of part of the lubrication chamber of [Fig.5],

[0043] [Fig.7] is another enlarged perspective view of part of the lubrication chamber of [Fig.5],

[0044] [Fig.8a] is an enlarged perspective view of a portion of the lubrication chamber of [Fig.5] when the oil level in the bottom of the lubrication chamber is below a threshold,

[0045] [Fig.8b] is an enlarged perspective view of a portion of the lubrication chamber of [Fig.5] when the oil level in the bottom of the lubrication chamber is above a threshold. Detailed description of the invention

[0046] An example of an aircraft turbomachine 1 according to the invention is shown in [Fig. 1]. The turbomachine 1 extends around and along a longitudinal axis X.

[0047] In the present application, the terms "upstream", "downstream" are defined with respect to the direction of gas flow in the turbomachine 1 along the longitudinal axis X.

[0048] The terms “axial”, “axially” are defined with respect to the longitudinal axis X.

[0049] The terms "radial" and "radially" are defined with respect to a radial axis Z which is perpendicular to the X axis of turbomachine 1.

[0050] The terms "internal", "interior", "external", "outside", "externally" are defined with respect to the distance from the longitudinal axis X along the radial axis Z.

[0051] The turbomachine 1 comprises, from upstream to downstream, a blower 2, at least one compressor such as a low-pressure compressor 3 and a high-pressure compressor 4, a combustion chamber 5, at least one turbine such as a high-pressure turbine 6 and a low-pressure turbine 7, and a nozzle (not shown).

[0052] The blower 2 allows the intake of an airflow which divides into a primary flow Fl and a secondary flow F2. The primary flow Fl passes through a primary channel la of the turbomachine 1 while the secondary flow F2 is directed towards a secondary channel 1b.

[0053] The primary flow Fl is compressed within the low pressure compressor 3 and then the high pressure compressor 4. The compressed air is then mixed with a fuel and burned within the combustion chamber 5. The gases formed by the combustion pass through the high pressure turbine 6 and low pressure turbine 7. The gases finally escape through the nozzle whose cross-section allows the acceleration of these gases to generate propulsion.

[0054] The fan 2 is, for example, shrouded. It is surrounded by an annular casing 2b centered on the longitudinal axis X. The casing 2b is, for example, surrounded by a nacelle (not shown) of the turbomachine 1.

[0055] In the particular example of [Fig. 1], the turbomachine 1 further comprises a rectifier 8. The rectifier 8 rectifies the secondary airflow F2 downstream of the fan 2 in order to improve the performance of the turbomachine 1. The housing 2b surrounds the rectifier 8. The rectifier 8 comprises, for example, fixed blades 8a supported by an inter-compressor housing 8b arranged axially between the low-pressure compressor 3 and the high-pressure compressor 4.

[0056] The inter-compressor housing 8b is arranged between the low-pressure and high-pressure compressors 3, 4. It includes, for example, an external ferrule 18. The external ferrule 18 is annular and centered on the longitudinal axis X. It is arranged inside the housing 2b.

[0057] The inter-compressor housing 8b further includes an annular internal ferrule 19 arranged coaxially inside the external ferrule 18.

[0058] Alternatively, the external and internal ferrules 18 are separate from the inter-compressor housing 8b. They can, for example, be arranged upstream of the inter-compressor housing 8b.

[0059] The inner ferrule 19 delimits with the outer ferrule 18 a portion of the primary vein la.

[0060] The secondary vein 1b is delimited by the casing 2b and the external ferrule 18.

[0061] In the particular example of [Fig. 1], the rotor of the low-pressure turbine 7 is connected to the rotor of the low-pressure compressor 3 by a low-pressure shaft 10. The rotor of the high-pressure turbine 6 is connected to the rotor of the high-pressure compressor 4 by a high-pressure shaft 9. The low-pressure shaft 10 is arranged at the inside of the high-pressure shaft 9 coaxially and extends along the longitudinal axis X.

[0062] The low-pressure shaft 10 is guided in rotation by bearings. An upstream bearing 10a is, for example, arranged radially between the low-pressure shaft 10 and an upstream bearing support 10b, connected, for example, to the inter-compressor housing 8b. The upstream bearing 10a is, for example, a ball bearing.

[0063] The blower 2 is mobile in rotation about the longitudinal axis X. The blower 2 comprises blades 2a regularly distributed on a disk centered on the longitudinal axis X.

[0064] The blower 2 is driven in rotation by a blower shaft 11. The blower shaft 11 is connected to the disk for its rotational drive. The blower shaft 11 is supported by a downstream bearing 11a arranged radially between the blower shaft 11 and a downstream bearing support 11b connected, for example, to the inter-compressor housing 8b. The downstream bearing 11a is, for example, a ball bearing. It is arranged upstream of the upstream bearing 10a.

[0065] The blower shaft 11 is also connected to the low-pressure shaft 10 via a speed reducer 12. The speed reducer 12 is of the mechanical type.

[0066] As more clearly seen in [Fig.2], the speed reducer 12 comprises a solar 13, a ring 14, at least one satellite 15 which meshes with the ring 14 and the solar 13, and a satellite carrier 16.

[0067] The solar element 13 is rotationally coupled with the low-pressure shaft 10. It forms the input of the reducer 12.

[0068] The speed reducer 12 comprises a plurality of satellites 15. Each satellite 15 has a central axis Y parallel to the longitudinal axis X.

[0069] The ring 14 is annular and is arranged around the longitudinal axis X. According to the example of [Fig.2], the ring 14 is rotationally coupled with the blower shaft 11. The ring 14 includes, for example, a fixing flange 14a connected to the blower shaft 11, for example, by means of fixing rods 14b such as screws.

[0070] The crown 14 forms the output of the reducer 12.

[0071] The planet carrier 16 is fixed in rotation about the longitudinal axis X. The planet carrier 16 is connected to a fixed structure of the turbomachine 1. According to the example of [Fig.2], the planet carrier 16 is connected to the inter-compressor housing 8b for example, by means of a flexible support 12a for example.

[0072] The speed reducer 12 is arranged in a lubrication chamber 17 of the turbomachine 1.

[0073] In order to ensure the lubrication of the speed reducer 12 in the lubrication chamber In the case of the turbomachine 1, a lubrication system 23 is shown, for example, in Figures 3 and 4. The lubrication system 23 includes a main lubrication circuit 24, an auxiliary lubrication circuit 25 for the speed reducer 12, the main and auxiliary circuits 24 and 25 being connected to the lubrication chamber 17. The lubrication system 23 may further include a device 26 for spraying lubricating oil into the lubrication chamber 17. The spraying device 26 is connected to the main circuit 24 and the auxiliary circuit 25.

[0074] The main circuit 24 typically includes a feed pump connected to a main reservoir (not shown). The feed pump is, for example, mechanically driven by the high-pressure shaft 9 via, for example, an accessory gearbox (known by the English acronym AGB for "accessory gearbox"). The accessory gearbox is, for example, housed in an interflow compartment of the turbomachine 1 arranged between the primary flow 1a and the secondary flow 1b. Thus, when the high-pressure shaft 9 is rotated, it primes the feed pump, which draws oil from the main reservoir and supplies oil to the spray device 26 as illustrated in [Fig. 3].

[0075] The main circuit further includes a return circuit connected to the main reservoir. The return circuit includes a recovery pump.

[0076] In certain cases, particularly when the high-pressure shaft 9 is barely rotating but the blower 2 is freely rotating (or self-rotating, also known as "windmilling"), or during the start-up or shutdown phases of the turbomachine 1, the feed pump is not primed and is no longer able to supply oil to the spray device 26. The speed reducer 12 is then no longer lubricated by the main circuit 25 as illustrated in [Fig. 4]. In such a case, lubrication of the speed reducer 12 is ensured by the auxiliary circuit 25.

[0077] The auxiliary circuit 25 includes an auxiliary pump 28 driven, for example, by an electric motor 29. The auxiliary pump 28 and the electric motor 29 are, for example, arranged outside the lubrication chamber 17. They are, for example, located in the nacelle. Alternatively, the auxiliary pump 28 and the electric motor 29 are arranged in the inter-vein compartment. The electric motor 29 is supplied with electrical energy by an electric generator 30 located, for example, in the lubrication chamber 17. The electric generator 30 provides electrical energy to the electric motor 29 from mechanical energy. The electric generator 30, for example, draws mechanical energy from the blower shaft 11. For example, the electric generator 30 is connected to the blower shaft 11 via gears 31. The electric motor 29 is, for example, controlled by a control unit 32.The control unit 32 allows the operating regime of the . auxiliary pump 28 via electric motor 29. The control unit 32 is for example a FADEC (for "Full Automatic Digital Engine Control" in English).

[0078] According to another example, the auxiliary pump 28 can be mounted on the low-pressure shaft 10 which, in the start-up, stop-start or self-rotation phases of the blower 2, is driven in rotation via the blower shaft 11. Its drive is then a function of the rotational speed of the low-pressure shaft 10.

[0079] The auxiliary circuit 25 further includes an auxiliary reservoir 20a connected to the auxiliary pump 28. The auxiliary pump 28 draws oil from the auxiliary reservoir 20a and supplies the spraying device 26 with lubricating oil.

[0080] The projection device 26 includes at least one nozzle 27 arranged in the lubrication chamber 17. The nozzle 27 allows the lubricating oil to be projected into the lubrication chamber 17. The projection device 26 advantageously includes two nozzles 27, a first nozzle 27a projecting the lubricating oil onto the reducer 12 and a second nozzle 27b projecting the oil onto the gears 31.

[0081] The lubrication chamber 17 is an upstream chamber. The lubrication chamber 17 is located, for example, between the downstream bearing 11a and the upstream bearing 10a. More particularly, the lubrication chamber 17 is axially delimited by the downstream bearing support 11b and the downstream bearing support 10b connected, for example, to the inter-compressor housing 8b.

[0082] As can be seen in Figures 5 and 6, the lubrication chamber 17 is annular. The lubrication chamber 17 is radially delimited by the inner ferrule 19. The inner ferrule 19 surrounds the ring 14.

[0083] The lubrication enclosure 17 includes an enclosure bottom F. The enclosure bottom F is located at the lowest point of the inner ferrule 19. The lowest point of the inner ferrule 19 is located at 6 o'clock (six o'clock by analogy to the corresponding position on the dial of a clock), as shown in [Fig.5].

[0084] The lubricating oil projected into the lubrication chamber 17 flows by gravity into the bottom of the chamber F.

[0085] The turbomachine 1 further includes an oil storage arm 20 extending radially between the outer shell 18 and the inner shell 19. It is further located at 6h as shown in [Fig.5].

[0086] With reference, for example, to [Fig. 6], the storage arm 20 is hollow. It has an internal cavity 200 opening into the lubrication chamber 17. In other words, the internal cavity 200 opens into the bottom of the chamber F, at the lowest point of the lubrication chamber 17. The storage arm 20 is arm C5. The storage arm 20 forms the auxiliary oil reservoir 20a. It is connected to the auxiliary pump 28.

[0087] The storage arm 20 is tubular. It has a closed radially external end 201 and a radially internal end 202 opposite the radially external end. external 201 open. The opening is in fluidic communication with the internal cavity 200. The opening allows the flow of oil from the lubrication chamber 17 by gravity into the internal cavity 200 of the storage arm 20.

[0088] The radially external end 201 is connected to the external ferrule 18 and the radially internal end 202 is connected to the internal ferrule 18. An outlet port connected to the auxiliary pump 28 can be provided on the radially external end 201.

[0089] The turbomachine 1 further includes an oil recovery arm 21. The recovery arm 21 extends radially between the outer shell 18 and the inner shell 19. The recovery arm 21 is, for example, adjacent to the storage arm 20. It is, for example, located at 7 o'clock (seven o'clock by analogy to the corresponding position on a clock face). The recovery arm 21 is also hollow to allow the circulation of oil within the recovery arm. The recovery arm 21 thus has an internal channel opening into the lubrication chamber 17. The recovery arm 21 is connected to the main circuit 24 and, in particular, to the return circuit of the main circuit 24. The recovery pump is, for example, connected to the recovery arm 21. The recovery pump draws oil from the recovery arm 21 to supply the main reservoir. The recovery pump is thus connected to the main reservoir and to the recovery arm 21.

[0090] The recovery arm 21 is also tubular and extends between a first end connected to the outer ferrule 18 and a second opposite end connected to the inner ferrule 19. The second end has an inlet communicating with the internal channel. This allows the oil to pass into the internal channel. The first end is, for example, closed. It includes an outlet port connected to the main circuit and, in particular, to the recovery pump.

[0091] When the volume of oil in the auxiliary reservoir 20a is at its maximum, the oil accumulates in the lubrication chamber 17, and in particular in the bottom of the chamber F, up to a level that allows it to pass into the recovery arm 21 by overflow and be pumped by the recovery pump. In order to prevent rotating parts of the speed reducer 12 from being submerged in the oil that accumulates in the bottom of the chamber F, and in particular the ring gear 14 which, being mobile in rotation, can cause the oil to overheat and degrade the speed reducer 12, the lubrication chamber 17 further includes an oil recovery scoop 22 from the lubrication chamber 17 illustrated in [Fig. 6].The recovery scoop 22 conveys oil from the lubrication chamber 17, and in particular from the bottom of the chamber F, to the recovery arm 21 in order to limit the oil level in the lubrication chamber 17, and in particular in the bottom of the chamber F, when the oil level in the internal cavity 220a reaches a predetermined threshold. The recovery scoop 22 thus allows the oil level in the bottom of the chamber F to be lowered when the oil level in the chamber reaches a certain threshold. The internal cavity 220 has reached a predetermined threshold. The only predetermined value in the internal cavity 220 corresponds in particular to the maximum volume of the auxiliary reservoir 20a, and therefore to the maximum volume of the internal cavity 220.

[0092] The recovery scoop 22 is arranged inside the lubrication enclosure 17.

[0093] The recovery scoop 22 extends circumferentially between the storage arm 20 and the recovery arm 21. It extends, for example, over an angular sector of less than 60°, preferably between 30° and 45°. The angular extent of the recovery scoop 22 is a function of the angular distance separating the storage arm 20 and the recovery arm 21.

[0094] The recovery scoop 22 extends circumferentially between a first end and a second opposite end.

[0095] The recovery scoop 22 has an internal oil circulation passage. The internal passage extends from the first end to the second end.

[0096] It also includes an oil inlet 220 arranged at the opening of the storage arm 20. The inlet 220 is therefore positioned approximately at the 6 o'clock position. This allows the oil to be transferred from the lubrication chamber 17, and in particular from the bottom of the chamber F, by overflow into the recovery scoop 22 when the volume of oil in the lubrication chamber 17 exceeds a threshold as illustrated in Figures 8a and 8b. Figure 8a illustrates a case where the volume of oil in the auxiliary reservoir 20a is at its maximum but the volume of oil in the bottom of the chamber F is below a threshold. Figure 8b illustrates a case where the volume of oil in the auxiliary reservoir 20a is at its maximum and the volume of oil in the bottom of the chamber F is above a given threshold. In this case, the oil is conveyed by overflow into the recovery scoop 22.

[0097] The recovery scoop 22 also has an outlet 221 arranged at the inlet of the recovery arm 21. This allows the oil to be drawn from the recovery scoop 22 by the recovery pump through the recovery arm 21.

[0098] The inlet 220 of the recovery scoop 22 is arranged at the first end of the recovery scoop 22 and the outlet 221 is arranged at the second end of the recovery scoop 22.

[0099] The recovery scoop 22 is metallic. The recovery scoop 22 has a polygonal cross-section, for example rectangular or square.

[0100] The recovery scoop 22 is fixed. The recovery scoop 22 is arranged inside the inner ferrule 19 and is integral with the inner ferrule 19. It is connected to the inner ferrule 19 by a connecting flange 22a.

[0101] Furthermore, oil is projected by centrifugal force through orifices 14c formed on the ring 14. In order to recover this oil, the lubrication chamber 17 further includes an oil recovery gutter 33 from the lubrication chamber. brification 17. The gutter 33 is arranged around the crown 14.

[0102] The gutter 33 has an annular body centered on the longitudinal axis X. The gutter 33 is rotationally fixed with respect to the longitudinal axis X. It is arranged inside the inner ferrule 19. It is connected to the inner ferrule 19. The gutter 33 is, for example, fixed to the inner ferrule 19 by means of a connecting flange 34 which cooperates with a complementary flange of the gutter 33. The gutter 33 is integral with the recovery scoop 22 by means of the inner ferrule 19. It is, for example, connected to the recovery scoop 22 by means of the connecting flange 22a which cooperates with a complementary connecting flange of the gutter 33.

[0103] The gutter 33 has a first radial wall 33b and a second radial wall 33c. The first and second radial walls 33a, 33b define an internal track 33d for the circulation of oil projected by centrifugal force from the ring 14. The first and second radial walls 33a, 33b extend radially inwards from the internal track 33d. The internal track 33d is opposite the ring 14. The internal track 33d forms the bottom of the gutter 33.

[0104] The additional flanges are for example attached to one of the radial walls 33a, 33b.

[0105] Advantageously, the gutter 33 includes a trumpet 35. The trumpet 35 has an inlet mouth 36 formed in the body 33a of the gutter 33 and an ejection outlet 37 of the oil towards the recovery scoop 22. The trumpet 35 thus makes it possible to direct the oil from the gutter 33 directly into the recovery scoop 22 in order to prevent the oil from the gutter 33 from filling the auxiliary reservoir 20a.

[0106] The inlet 220 of the recovery scoop 22 is opposite the ejection outlet 37. They are approximately located at 6 o'clock.

[0107] The cross-sections of the inlet 36 and the ejection outlet 37 are, for example, rectangular. Preferably, the cross-section of the inlet 36 is larger than the cross-section of the ejection outlet 37. This accentuates the venturi shape of the nozzle 35 and thus the jet nozzle effect, which draws the stagnant oil from the bottom of the housing F into the recovery scoop 22 by the Venturi effect. Such a nozzle 35 thus minimizes the power of the recovery pump, which does not need to be oversized to draw the oil from the recovery scoop 22 through the recovery arm 21. This results in a reduction in the mass and size of the turbomachine 1.

[0108] Preferably, the section of the ejection outlet 37 is between 20% and 80% of the section of the inlet 220. This further improves the ejection of oil from the gutter 33 into the recovery scoop 22.

[0109] The trumpet 35 is mounted on the storage arm 20. The trumpet 35 is curved and extends radially outwards from the annular body 33a. The trumpet 35 comprises a first portion 35a extending from body 33a and a second portion 35b extending towards recovery scoop 22. The first portion 35a is connected to the second portion 35b by a curved portion 35c.

[0110] The recovery scoop 22 according to the invention has the advantage of preventing rotating components of the speed reducer 12, such as the ring gear 14, from becoming submerged in the stagnant oil at the bottom of the enclosure F. The oil can be efficiently evacuated into the main circuit 24. Also, the main circuit can be equipped with a recovery pump connected to the main reservoir and the auxiliary reservoir, which has minimal power thanks to the presence of the nozzle 35.

Claims

Demands

1. Turbomachine (1) for an aircraft, extending about a longitudinal axis (X) and comprising: - a fan (2) driven in rotation about the longitudinal axis (X) by a fan shaft (11), - a low-pressure shaft (10) connected to the fan shaft (11) by a mechanical speed reducer (12), - a lubrication chamber (17) in which the speed reducer (12) is arranged, the lubrication chamber (17) being radially delimited by an annular inner shell (19) centered on the longitudinal axis (X), - an outer shell (18) arranged coaxially around the inner shell (19), - a storage arm (20) arranged at 6 o'clock and extending radially between the inner (19) and outer (18) shells,the storage arm (20) having an internal cavity (200) opening into the lubrication chamber (17) and forming an auxiliary oil reservoir (20a) intended to be connected to an auxiliary lubrication circuit (25) for the speed reducer (12), and - an oil recovery arm (21) from the lubrication chamber (17) extending radially between the internal (19) and external (18) ferrules and intended to be connected to a main lubrication circuit (24) for the speed reducer (12), the recovery arm (21) having an internal channel opening into the lubrication chamber (17),characterized in that the lubrication chamber (17) further comprises: - an oil recovery scoop (22) for the lubrication chamber (17) configured to convey the oil from the lubrication chamber (17) to the recovery arm (21) and to limit the oil level in the lubrication chamber (17) when the oil level in the internal cavity (220) has reached a predetermined threshold.

2. Turbomachine according to the preceding claim, characterized in that the recovery scoop (22) extends circumferentially between the storage arm (20) and the recovery arm (21).

3. Turbomachine according to any one of the preceding claims, characterized in that the recovery scoop (22) is arranged inside the lubrication chamber (17) and is integral with the shell internal (19).

4. Turbomachine according to any one of the preceding claims, characterized in that the storage arm (20) has a closed radially external end (201) and a radially internal end (202) having an opening, and in that the recovery scoop (22) has an inlet (220) arranged at the opening so that oil is transferred by overflow into the inlet (220) when the volume of oil in the lubrication chamber (17) exceeds a threshold.

5. Turbomachine according to any one of the preceding claims, characterized in that the speed reducer (12) comprises a solar (13) rotationally coupled with the low pressure shaft (10), a ring (14) extending around the longitudinal axis (X) and rotationally coupled with the blower shaft (11), at least one satellite (15) meshing with the ring (14) and the solar (13) and a fixed satellite carrier (16), the inner shell (19) being arranged around the ring (14).

6. Turbomachine according to the preceding claim, characterized in that the lubrication chamber (17) comprises a gutter (33) for recovering oil from the lubrication chamber (17), this gutter (33) being arranged in the inner shell (19) and connected to the inner shell (19) and comprising an annular body (33a) centered on the longitudinal axis (X) and a trumpet (35) having an inlet mouth (36) formed in the body (33a) of the gutter (33) and an ejection outlet (37) of the oil towards the recovery scoop (22).

7. Turbomachine according to the preceding claim, characterized in that the trumpet (35) surmounts the storage arm (20).

8. Turbomachine according to any one of claims 6 or 7, characterized in that the nozzle (35) is curved and extends radially outwards from the body (33a).

9. Turbomachine according to any one of claims 6 to 8, characterized in that the section of the ejection outlet (37) is between 20% and 80% of the section of the inlet (220) of the recovery scoop (22).

10. Turbomachine according to any one of claims 6 to 9, characterized in that the inlet mouth section (36) is greater than or equal to the ejection outlet section (37).

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