Aircraft turbine engine

Abstract

The invention relates to a turbine engine (1) for an aircraft, comprising an annular lubrication enclosure (17) in which a reduction gear (12) is arranged; a lubrication system for lubricating a reduction gear (12), the lubrication system comprising a main lubrication circuit (24) and an auxiliary lubrication circuit (25) connected to a lubrication enclosure (17), the auxiliary circuit (25) being connected to an auxiliary reservoir (31), an inner shroud (19) extending around the lubrication enclosure (17), the auxiliary reservoir (31) being located outside an outer shroud (18), one of the arms, referred to as a 6 o'clock arm (20), is tubular and is in a 6 o'clock position, the lubrication enclosure (17) comprising a deflector (22) connected to a radially inner end (20a) of the 6 o'clock arm (20) and configured to deflect oil flowing by gravity from the lubrication enclosure (17) towards an upstream compartment (21a) of the 6 o'clock arm (20).

Description

Technical Field

[0001] The present invention relates to the field of aircraft turbine engines and more particularly to the field of turbine engines comprising a system for lubricating a reduction gear, the system comprising a main lubrication circuit and an auxiliary lubrication circuit. Background Art

[0002] An aircraft turbine engine generally comprises, from upstream to downstream in the direction of air flow, a fan rotating about a longitudinal axis, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine and an exhaust nozzle.

[0003] The fan enables the suction of an air flow which is divided into a primary flow and a secondary flow. The primary flow passes through a primary duct of the turbine engine, while the secondary flow is directed towards a secondary duct surrounding the primary duct.

[0004] The turbine engine also includes an inlet casing centered on the longitudinal axis and defining an inlet to the main duct. The inlet casing includes an annular inner shroud surrounded by an annular outer shroud connected by radial arms.

[0005] The main flow is compressed in the compressor. The compressed air is then mixed with fuel and burned in the combustion chamber. The gases produced by the combustion pass through the turbine and are then discharged through a nozzle whose cross section enables these gases to be accelerated to produce propulsion.

[0006] The rotor of the low-pressure turbine is connected to the rotor of the low-pressure compressor via a low-pressure shaft, and the rotor of the high-pressure turbine is connected to the rotor of the high-pressure compressor via a high-pressure shaft. In addition, the fan is driven to rotate by a fan shaft connected to the low-pressure shaft via a reduction gear, so that the fan can be driven at a rotation speed lower than the rotation speed of the low-pressure shaft. The reduction gear is usually arranged in a lubrication enclosure for lubricating the reduction gear. The lubrication enclosure is usually located inside the inner shroud.

[0007] In order to ensure lubrication of the reduction gear in the lubricating enclosure, the turbine engine also includes a main lubrication circuit of the reduction gear connected to the lubricating enclosure. The main circuit includes an oil feed pump of the reduction gear connected to the main oil reservoir. The oil feed pump is usually driven in rotation by the high-pressure shaft via the accessory gearbox.

[0008] During certain operating phases of the turbine engine, such as the free rotation phase of the fan (known as "windmilling"), during which the fan shaft is driven in rotation and thus drives the low-pressure shaft, the rotation speed of the high-pressure shaft is not sufficient to drive the feed pump at a speed sufficient to provide the flow rate required to lubricate the reduction device. However, even during these operating phases of the turbine engine, it is necessary to ensure the lubrication of the reduction device.

[0009] In this context, a turbine engine comprises an auxiliary lubrication circuit for the reduction gear. The auxiliary circuit generally comprises an auxiliary pump powered by, for example, a generator or driven by the low-pressure shaft, which enables the auxiliary pump to be activated even in the case of free-spinning of the fan and low rotational speed of the high-pressure shaft.

[0010] In order to supply oil to the auxiliary circuit, document FR-A1-3 075 875 proposes to recover the oil that flows by gravity into the bottom of the enclosure. To this end, one of the radial arms, located at 6 o'clock, has an inner cavity leading to the enclosure via an oil inlet. The arm also has a first oil outlet connected to the main circuit by a first pipe and a second oil outlet connected to the auxiliary circuit by a second pipe. The first pipe is connected to an oil recovery pump that supplies the main reservoir, and the second pipe is connected to an auxiliary pump in the auxiliary circuit.

[0011] Furthermore, according to this document, radial partitions are arranged in the inner cavity and delimit an upstream compartment to which the second tube is connected and a downstream compartment to which the first tube is connected.

[0012] Thus, for example, during the phases when the fan is free-spinning when the supply pump is not activated, the auxiliary pump and the recovery pump draw oil by gravity flow through each of the pipes into the arm located at 6 o'clock. Thus, during these phases, oil can be supplied to the auxiliary circuit to lubricate the reduction gear.

[0013] Although this solution provides an amount of oil for auxiliary lubrication of the reduction gear in the case of free rotation of the fan, for example, the amount of oil available for these operating phases cannot be guaranteed and may prove to be insufficient. In fact, the document teaches that in order to maximize oil recovery, the oil inlet has a maximum axial dimension, which extends over the entire axial width of the arm and is limited between the upstream axial wall and the downstream axial wall of the arm. The combination of the configuration of the oil inlet and the presence of the radial wall prevents sufficient oil recovery in the first tube. In fact, the oil flowing down the arm by gravity supplies the upstream compartment and the downstream compartment. Therefore, even if the auxiliary circuit does not have enough volume during the operating phase of free rotation of the fan, oil can be supplied to the main circuit. During these phases, insufficient lubrication of the reduction gear may occur, which may cause irreversible damage to the reduction gear.

[0014] It is therefore necessary to provide a turbine engine that ensures sufficient, effective and reliable lubrication of the reduction gear during all operating phases of the turbine engine. Summary of the invention

[0015] To this end, the invention proposes a turbine engine for an aircraft, the turbine engine extending about a longitudinal axis and comprising:

[0016] - a fan, the fan being driven in rotation about a longitudinal axis by a fan shaft,

[0017] - Low-pressure shaft, which is connected to the fan shaft through a mechanical reduction gear,

[0018] - an annular lubricating enclosure in which the reduction device is arranged,

[0019] a lubrication system for lubricating the reduction gear, the lubrication system comprising a main lubrication circuit and an auxiliary lubrication circuit connected to the lubrication enclosure, the auxiliary circuit being connected to an auxiliary reservoir,

[0020] - an air intake housing comprising an inner shroud and an outer shroud centered on the longitudinal axis and connected by an arm, the inner shroud extending around the lubrication enclosure, the auxiliary reservoir being located outside the outer shroud, one of the arms, referred to as the 6 o'clock arm, being tubular and located at the 6 o'clock position, the 6 o'clock arm comprising:

[0021] a radially outer end portion and an opposite radially inner end portion, the radially outer end portion being connected to the outer shroud,

[0022] The inner cavity leads to the lubrication enclosure through the oil inlet,

[0023] The first oil outlet is connected to the main circuit.

[0024] a second oil outlet connected to the auxiliary reservoir, the first oil outlet and the second oil outlet being diametrically opposite to the oil inlet, and

[0025] A radial partition is arranged in the inner cavity and defines an upstream compartment and a downstream compartment, the second outlet is located in the upstream compartment, and the first outlet is located in the downstream compartment.

[0026] The turbine engine according to the invention is notable in that the lubrication enclosure also comprises a deflector connected to the radially inner end of the 6 o'clock arm and configured to deflect oil flowing by gravity from the lubrication enclosure towards the upstream compartment.

[0027] Due to the deflector of the arm, the oil flows in a privileged manner into the upstream compartment connected to the auxiliary reservoir. When the amount of oil in the auxiliary reservoir exceeds the maximum volume of the auxiliary reservoir, the oil accumulates in the upstream compartment. When the amount of oil in the upstream compartment is at the maximum value of the oil amount, the oil flowing by gravity overflows into the downstream compartment. This oil then circulates to the main circuit. Therefore, the auxiliary reservoir is preferentially supplied with oil, which ensures lubrication of the reduction gear when the auxiliary circuit is active.

[0028] In addition, according to the present invention, the auxiliary reservoir extends outside the outer shroud. Such a configuration of the auxiliary reservoir enables a large volume of the auxiliary reservoir without interfering with the flow of the main flow in the main duct defined by the inner shroud and the outer shroud.

[0029] Thanks to the invention, a sufficient amount of oil can be stored in the auxiliary reservoir to supply the auxiliary circuit. Thus, the reduction gear can be reliably and efficiently lubricated during all operating phases of the turbine engine.

[0030] The present invention may include one or more of the following features taken alone or in combination with each other:

[0031] - the deflector comprises an axial wall connected to the 6 o'clock arm and the inner shroud, the axial wall having a flow surface inclined towards the inner cavity so that the axial wall continuously moves away from the longitudinal axis as the axial wall advances upstream of the 6 o'clock arm,

[0032] - the 6 o'clock arm comprises axially opposite upstream and downstream walls extending radially between the inner and outer ends, the oil inlet being axially delimited by the edge of the deflector and the upstream wall of the 6 o'clock arm,

[0033] - the circumferential width of the deflector is equal to the circumferential width of the 6 o'clock arm,

[0034] - the passage cross section of the oil inlet is equal to or greater than the passage cross section of the first oil outlet,

[0035] - the radially outer end of the 6 o'clock arm has a bottom wall, the second oil outlet is formed in the bottom wall, and the partition extends radially from the bottom wall towards the inside of the 6 o'clock arm,

[0036] - a separation barrier is arranged in the inner cavity and extends radially from the deflector at least to the second oil outlet,

[0037] - an exhaust port is formed in the deflector and opens into the lubrication enclosure and into the inner cavity on the downstream compartment side,

[0038] - the auxiliary reservoir is directly connected to the second oil outlet,

[0039] - the auxiliary reservoir is housed in a venous compartment which divides the air flow generated by the fan into a primary flow and a secondary flow,

[0040] -The main circuit includes:

[0041] - a recovery pump having a hydraulic inlet line and a hydraulic outlet line,

[0042] - a hydraulic anti-cavitation line connected to the hydraulic outlet line of the recovery pump, and

[0043] -Hydraulic auxiliary valve, which is arranged between the recovery pump and the arm. The auxiliary valve includes:

[0044] a first inlet port, the first inlet port being connected to the first oil outlet,

[0045] The second inlet port is connected to the hydraulic anti-cavitation line.

[0046] an outlet port, the outlet port being connected to the hydraulic inlet line of the recovery pump, and

[0047] A member is movable between a first position in which the outlet port is in fluid communication with the first inlet port and a second position in which the outlet port is in fluid communication with the second inlet port. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Other features and advantages will emerge from the following description of non-limiting embodiments of the invention and with reference to the accompanying drawings, in which:

[0049] Figure 1 is a schematic diagram of a longitudinal section of an aircraft turbine engine according to the invention,

[0050] Figure 2 Is equipped with Figure 1 Schematic diagram of a longitudinal cross section of a reduction gear on a turbine engine,

[0051] Figure 3 According to an example of the present invention, Figure 2 Schematic diagram of the system for lubricating the reduction gear in FIG.

[0052] Figure 4 According to another embodiment of the present invention, Figure 2 Schematic diagram of the system for lubricating the reduction gear in FIG.

[0053] Figure 5a is a schematic diagram of a longitudinal section of an arm at the 6 o'clock position according to a first embodiment of the present invention,

[0054] Figure 5b is a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a variation of the first embodiment of the present invention,

[0055] Figure 6a is a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a first embodiment when the turbine engine is stationary and the primary circuit and the auxiliary circuit are stationary,

[0056] Figure 6bis a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a first embodiment when the turbine engine is in a first nominal operating phase, during which the amount of oil in the upstream compartment is less than the maximum volume of the upstream compartment, the primary circuit is active and the auxiliary circuit is stationary,

[0057] Figure 6c is a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a first embodiment when the turbine engine is in a second nominal operating phase, during which the amount of oil in the upstream compartment is greater than the maximum volume of the upstream compartment, the primary circuit is active and the auxiliary circuit is stationary,

[0058] Figure 6d is a schematic diagram of a longitudinal section of an arm according to a first embodiment at 6 o'clock when the turbine engine is in a third operating phase (for example free rotation of the fan), during which the auxiliary circuit is active,

[0059] Figure 7 is a longitudinal sectional view of an arm at 6 o'clock according to a second embodiment of the present invention,

[0060] Figure 8a is a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a second embodiment when the turbine engine is stationary and the primary circuit and the auxiliary circuit are stationary,

[0061] Figure 8b is a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a second embodiment when the turbine engine is in a first nominal operating phase, during which the amount of oil in the upstream compartment is less than the maximum volume of the upstream compartment, the primary circuit is active and the auxiliary circuit is stationary,

[0062] Figure 8c is a schematic diagram of a longitudinal section of an arm at 6 o'clock according to a second embodiment when the turbine engine is in a second nominal operating phase, during which the amount of oil in the upstream compartment is greater than the maximum volume of the upstream compartment, the primary circuit is active and the auxiliary circuit is stationary,

[0063] Figure 8d is a schematic diagram of a longitudinal section of an arm according to a second embodiment at 6 o'clock when the turbine engine is in a third operating phase (for example free rotation of the fan) during which the auxiliary circuit is active. DETAILED DESCRIPTION

[0064] Figure 1 An example of an aircraft turbine engine 1 according to the invention is shown. The turbine engine 1 surrounds a longitudinal axis X and extends along the longitudinal axis X.

[0065] In the present application, the terms “axial”, “axially”, “radially” and “radially” are defined relative to the longitudinal axis X.

[0066] The terms “upstream”, “downstream”, “axial” and “axially” are defined relative to the direction of the air flow along the longitudinal axis X in the turbine engine 1 .

[0067] The terms “inner”, “inner”, “outer”, “outer”, “externally” are defined relative to the distance from the longitudinal axis X along a radial axis Z perpendicular to the longitudinal axis X.

[0068] The terms "horizontal" and "vertical" are defined relative to the direction of gravity, which defines vertical. Horizontal is perpendicular to the direction of gravity, and vertical is parallel to the direction of gravity.

[0069] The turbine engine 1 includes, from upstream to downstream, a fan 2, at least one compressor (eg, a low-pressure compressor 3 and a high-pressure compressor 4), a combustion chamber 5, at least one turbine (eg, a high-pressure turbine 6 and a low-pressure turbine 7), and a nozzle for exhausting gas.

[0070] The fan 2 sucks in an air flow F, which is divided into a main flow F1 and a secondary flow F2. The main flow F1 passes through a main duct 1a of the turbine engine 1, while the secondary flow F2 is directed toward a secondary duct 1b surrounding the main duct 1a.

[0071] The main flow F1 is compressed in the low-pressure compressor 3 and then in the high-pressure compressor 4. The compressed air is then mixed with fuel and burned in the combustion chamber 5. The gases formed by the combustion pass through the high-pressure turbine 6 and the low-pressure turbine 7. Finally, the gases escape through a nozzle whose cross section enables them to be accelerated to generate propulsion.

[0072] The fan 2 moves in rotation about a longitudinal axis X. The fan 2 comprises blades 2a evenly distributed around a disk centered on the longitudinal axis X.

[0073] The fan 2 is, for example, of the ducted type. The turbine engine 1 then comprises an annular nacelle 2 b surrounding the fan 2 centered on the longitudinal axis X. The nacelle 2 b is, for example, supported by a fan casing (not shown).

[0074] The turbine engine 1 further comprises an air intake casing 8. The air intake casing 8 is located, for example, inside the nacelle 2b. The air intake casing 8 is arranged, for example, axially between the fan 2 and the low-pressure compressor 3. The air intake casing 8 forms an air intake opening for the main duct 1a. In particular, the air intake casing 8 comprises an outer shroud 18 and an inner shroud 19 arranged in the outer shroud 18. The outer shroud 18 and the inner shroud 19 are centered on the longitudinal axis X and are connected by radial arms.

[0075] The main duct 1 a is delimited downstream of the air intake opening by an inner casing 110 arranged downstream of the outer shroud 18 and the inner shroud 19 .

[0076] The secondary duct 1 b is also radially delimited by the nacelle 2 b and an intervein casing 180 which is arranged radially between the nacelle 2 b and the air inlet casing 8 .

[0077] Furthermore, the choroid compartment 1c is arranged radially between the secondary duct 1b and the main duct 1a. The choroid compartment 1c has a first zone Z1 delimited internally by the outer shield 18 and externally by the interchoroid housing 180. The choroid compartment 1c comprises a second zone Z2 downstream of the first zone Z1.

[0078] exist Figure 1 In the particular example shown, the rotor of the low-pressure turbine 7 is connected to the rotor of the low-pressure compressor 3 via a low-pressure shaft 10. The rotor of the high-pressure turbine 6 is connected to the rotor of the high-pressure compressor 4 via a high-pressure shaft 9. The low-pressure shaft 10 is arranged coaxially inside the high-pressure shaft 9 and extends along the longitudinal axis X.

[0079] The low-pressure shaft 10 is guided in rotation by a bearing. An intermediate bearing 10a is, for example, radially arranged between the low-pressure shaft 10 and a first bearing support 10b, which is, for example, connected to the inner shroud 19. The intermediate bearing 10a is, for example, a ball bearing.

[0080] The fan 2 is driven to rotate by a fan shaft 11. The fan shaft 11 is connected to the disk to drive the disk to rotate. The fan shaft 11 is supported by a downstream bearing 11a, which is radially arranged between the fan shaft 11 and a second bearing support 11b, which is connected to the inner shroud 19. The downstream bearing 11a is, for example, a ball bearing. The downstream bearing 11a is located upstream of the intermediate bearing 10a. The downstream bearing 11a is arranged on the downstream end of the fan shaft 11.

[0081] The fan shaft 11 is also connected to the low-pressure shaft 10 via a reduction gear 12. The reduction gear 12 is a mechanical reduction gear.

[0082] like Figure 2 It can be seen that the reduction gear 12 includes a sun gear 13 , a ring gear 14 , at least one planetary gear 15 meshing with the ring gear 14 and the sun gear 13 , and a planetary carrier 16 .

[0083] The sun gear 13 is rotationally coupled with the low-pressure shaft 10. The sun gear 13 forms an inlet of the reduction device 12.

[0084] The reduction gear 12 includes a plurality of planetary gears 15. Each planetary gear 15 has a central axis Y parallel to the longitudinal axis X.

[0085] The ring gear 14 is annular and is arranged about a longitudinal axis X. Figure 1 In the example in FIG. 1 , the ring gear 14 is rotationally coupled with the fan shaft 11 . The ring gear 14 comprises, for example, an attachment flange 14a, which is connected to the fan shaft 11 by means of, for example, an attachment rod 14b such as a screw. The ring gear 14 forms an outlet of the reduction device 12 .

[0086] 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 turbine engine 1. Figure 2 As shown, the planet carrier 16 is connected to the inner shroud 19 , for example via a flexible support 11 c .

[0087] The reduction gear 12 is composed of gears and rolling bearings that need lubrication. For this purpose, lubricating oil is sprayed onto the reduction gear 12. In order to protect other components of the turbine engine 1 from the influence of the oil, the reduction gear 12 is arranged in an annular lubricating enclosure 17. The lubricating enclosure 17 is, for example, an upstream enclosure. The lubricating enclosure 17 is located inside the inner shroud 19. The lubricating enclosure 17 may include an upstream bearing 11a and an intermediate bearing 10a.

[0088] The lubrication enclosure 17 has an enclosure bottom F. The enclosure bottom F is located at the lowest point of the lubrication enclosure 17 (ie, the inner shroud 19). The lubrication oil flows into the enclosure bottom F by gravity.

[0089] In the radial arm extending radially between the outer shield 18 and the inner shield 19, similar to the corresponding position on the dial of a clock, the tubular arm 20 is located at the 6 o'clock position. For simplicity, in the rest of the specification, the arm located at the 6 o'clock position will be referred to as "arm".

[0090] The arm 20 comprises a radially inner end 20a, which is connected, for example, to the lubrication enclosure 17, in particular to the enclosure bottom F. The radially inner end 20a is, for example, open. The arm 20 also comprises a radially outer end 20b connected to the outer shroud 18 and opposite to the radially inner end 20a. The radially outer end 20b has an axial bottom wall 20b', which is preferably formed by the outer shroud 18.

[0091] The arm 20 also has a first face and a second face that are opposite to each other and extend radially between the radially outer end 20b and the radially inner end 20a. The first face and the second face intersect at the upstream edge 201 and the downstream edge 202. The upstream edge 201 and the downstream edge 202 are axially connected to each other at their upper ends by a bottom wall 20b'.

[0092] The arm 20 further comprises an inner cavity 200 which opens via an oil inlet 200a to the lubrication enclosure 17, in particular to the enclosure bottom F. Thus, lubrication oil can flow by gravity from the lubrication enclosure 17 into the arm 20. The oil inlet 200a is formed, for example, in the inner shroud 19 and opens into the inner cavity 200.

[0093] The arm 20 further includes a first oil outlet 20c and a second oil outlet 20d radially opposite to the oil inlet 200a. For example, the first oil outlet 20c and the second oil outlet 20d are formed in the bottom wall 20b' and / or the downstream wall 202. The first outlet 20c is formed in the downstream wall 202, for example, and the second outlet 20d is formed in the bottom wall 20b'. The oil inlet 200a has a first passage cross section S1, and the first oil outlet 20c has a second passage cross section S2. Preferably, the first passage cross section S1 is greater than or equal to the second passage cross section S2.

[0094] The arm 20 further includes a radial partition 21 arranged in the inner cavity 200. The radial partition 21 is axially arranged between the first outlet 20c and the second outlet 20d. The radial partition 21 is located downstream of the oil inlet 200a. The radial partition 21 defines an upstream compartment 21a and a downstream compartment 21b in the arm 20. The upstream compartment 21a and the downstream compartment 21b each have a predetermined volume. The first outlet 20c is located in the downstream compartment 21b, and the second outlet 20d is located in the upstream compartment 21a.

[0095] The radial partition 21 extends radially from the bottom wall 20b' toward the inside. The radial partition 21 has a radial inner free end 210 opposite to the bottom wall 20b'.

[0096] Preferably, radial baffles 21 have a maximum height H configured so that the volume of upstream compartment 21a is sufficient to prevent oil from escaping into lubrication enclosure 17 when turbine engine 1 is tilted upstream at the maximum permissible angle (typically during nose-down maneuvers of the aircraft).

[0097] When the turbine engine 1 is tilted upstream at the maximum permissible tilt angle, the free end 210 is located outside a first straight line D1 passing through the inner end of the upstream wall 201 and parallel to the horizontal plane. This prevents oil from escaping into the lubrication enclosure 17 when the turbine engine 1 is tilted upstream to the maximum permissible angle (usually during nose-down maneuvers of the aircraft). For example, the ratio between the maximum height H of the radial partition 21 and the height H' of the upstream wall 201 is between 40% and 90%.

[0098] According to the invention, the lubrication enclosure 17 further comprises a deflector 22 connected to the radially inner end 20a of the arm 20. The deflector 22 is configured to deflect the oil flowing by gravity from the lubrication enclosure 17 towards the upstream compartment 21a.

[0099] The deflector 22 is connected to the inner shield 19. Preferably, the deflector 22 forms an integral piece with the inner shield 19. In another example, the deflector 22 and the inner shield 19 may be two separate parts connected to each other.

[0100] The deflector 22 comprises an axial wall 22a connected to the inner shroud 19 and to the arm 20, in particular to the lower end of the downstream wall 202 of the arm 20. The axial wall 22a has a flow surface inclined towards the inner cavity 200 of the arm 20. In this way, the axial wall 22a moves continuously away from the longitudinal axis X as it moves upstream of the arm 20. Preferably, the axial wall 22a is inclined at an angle of inclination or slope α comprised between 5° and 45° relative to the longitudinal axis X. This slope α ensures that the oil flows by gravity into the upstream compartment 21a despite the downstream inclination of the turbine engine 1, typically during nose-up maneuvers of the aircraft, for example during the take-off phase of the aircraft.

[0101] Advantageously, the circumferential width of the deflector 22 is equal to the circumferential width of the arm 20. The deflector 22 extends circumferentially between the first face and the second face of the arm 22. This prevents the oil from flowing by gravity into the downstream compartment 21b.

[0102] The deflector 22 partially covers the radially inner end 20a of the arm 20. The deflector 22 has an edge 22b axially opposite the downstream wall 202 of the arm 20. This edge 22b axially delimits with the upstream wall 201 of the arm 20 an oil inlet 200a.

[0103] Preferably, the radial partition 21 is positioned in the inner cavity 200 of the arm 20 so that when the turbine engine 1 is tilted downstream at the maximum permissible angle (typically during nose-up maneuvers of the aircraft, such as during the take-off phase of the aircraft), oil flows from the bottom F of the enclosure into the upstream compartment 21a.

[0104] according to Figure 5a and Figure 5b In the first embodiment shown, when the turbine engine 1 is tilted downstream at the maximum authorized tilt angle, the free end 210 of the partition 21 is located on or downstream of the second straight line D2, which passes through the free edge 22b of the deflector 22 and is parallel to the vertical plane. This ensures that during nose-up maneuvers of the aircraft, the oil flows into the upstream compartment 21a and not into the downstream compartment 21b.

[0105] according to Figure 5bIn the variant of the first embodiment shown, the partition 21 has a curved section 211 connected to the bottom wall 20b'. This increases the volume of the upstream compartment 20a. According to this variant, in order to minimize pressure losses, the second cross section S2 is smaller than the intermediate oil passage cross section S3 of the downstream compartment 21b.

[0106] exist Figure 7 In the second embodiment shown, the partition barrier 23 is arranged in the upstream compartment 21a. The partition barrier 23 divides the upstream compartment 21a into a first sub-compartment 21a' and a second sub-compartment 21a". The second sub-compartment 21a" is located between the downstream compartment 21b and the first sub-compartment 21a'. The first sub-compartment 21a' and the second sub-compartment 21a" are separated by the partition barrier 23.

[0107] Preferably, the partition barrier portion 23 extends radially from the deflector 22 toward the outside and extends at least to the second outlet 20d. Figure 7 In the example shown, the separation barrier 23 extends into the second outlet 20d. Even more preferably, the separation barrier 23 is connected to the edge 22b of the deflector 22. The separation barrier 23 and the deflector 22 may form one piece or two separate parts joined together by, for example, gluing.

[0108] Preferably, the exhaust port 22c is formed in the axial wall 22a of the deflector 22. The exhaust port 22c is continuous, and the exhaust port 22c opens to the lubrication enclosure 17 and a portion of the inner cavity 200 on the downstream compartment 21b side.

[0109] In order to ensure lubrication of the reduction gear 12 in the lubricating enclosure 17, the turbine engine 1 comprises a lubricating device for example Figure 3 and Figure 4 The reduction gear unit 12 is shown with a lubrication system for lubricating it.

[0110] The lubrication system comprises a main lubrication circuit 24 and an auxiliary lubrication circuit 25, which are connected to the lubrication enclosure 17. The lubrication system 23 may also comprise a selective injection device 26 for injecting lubricating oil into the lubrication enclosure 17, which is connected to the main circuit 24 and the auxiliary circuit 25.

[0111] The main circuit 24 typically comprises a supply circuit 240 connecting a main reservoir 240b to the lubrication enclosure 17. The supply circuit 240 comprises a supply pump 240a, which is installed between the main reservoir 240b and the lubrication enclosure 17, in particular between the main reservoir 240b and the selective injection device 26. The supply pump 240a is mechanically driven, for example, by the high-pressure shaft 9. Advantageously, the supply pump 240a is connected to the high-pressure shaft 9 via an accessory gearbox (AGB). The accessory box is housed, for example, in the vein compartment 1c. Thus, when the high-pressure shaft 9 is driven to rotate, the high-pressure shaft 9 starts the supply pump 240a, which draws oil from the main reservoir 240b and supplies oil to the selective injection device 26. The supply circuit 240 may also comprise at least one air / oil exchanger 240c, which is arranged, for example, between the selective injection device 26 and the supply pump 240a.

[0112] The main circuit 24 also comprises a return circuit 241 which connects the main reservoir 240b to the downstream compartment 21b of the arm 20. The return circuit 241 comprises a recovery pump 241a which is advantageously located in the choroidal compartment 1c. The recovery pump 241a is connected to the main reservoir 240b and to the first outlet 20c of the arm 20. In particular, the recovery pump 241a has an inlet hydraulic line 242a connected to the first outlet 20c and an outlet hydraulic line 242b connected to the main reservoir 240b.

[0113] In some cases, the high-pressure shaft 9 is not driven to rotate, or is driven at a speed that is insufficient to drive the feed pump 240a to rotate. For example, when the fan 2 is in free rotation (or automatic rotation, also known as "windmill rotation"), or during the startup or shutdown phase of the turbine engine 1, the feed pump 240a is not started and can no longer supply oil to the selective injection device 26. Then, the reduction device 12 is no longer lubricated by the main circuit 24. In this case, the lubrication of the reduction device 12 is provided by the auxiliary circuit 25.

[0114] The auxiliary circuit 25 is a closed lubrication circuit for the lubrication enclosure 17 . The auxiliary circuit 25 comprises an auxiliary pump 28 connected to an auxiliary reservoir 31 and to the lubrication enclosure 17 , in particular to the selective injection device 26 .

[0115] The auxiliary reservoir 31 is located outside the outer shroud 18. Preferably, the auxiliary reservoir 31 is located in the choroid compartment 1c, for example in the first zone Z1. Since the auxiliary reservoir 31 is located outside the main duct 1a, the auxiliary reservoir 31 can have a large internal volume without affecting the aerodynamic performance of the turbine engine 1. This means that a large amount of oil can be stored.

[0116] The auxiliary reservoir 31 is connected to the second oil outlet 20d of the arm 20. In this way, the auxiliary reservoir 31 is connected to the upstream compartment 21a. The oil flowing into the upstream compartment 21a by gravity is stored in the auxiliary reservoir 31. Due to the deflector 22 of the present invention, the auxiliary reservoir 31 is filled preferentially. The risk of insufficient oil supply to the auxiliary reservoir 31 is limited. This ensures reliable lubrication of the reduction gear 12 regardless of the operating phase of the turbine engine 1.

[0117] Preferably, the auxiliary reservoir 31 is directly connected to the second oil outlet 20 d of the arm 20 .

[0118] The auxiliary pump 28 is driven, for example, by an electric motor 29. The auxiliary pump 28 and the electric motor 29 are located, for example, in the venous compartment 1c. The electric motor 29 is supplied with electrical energy by a generator (not shown) located, for example, in the lubrication enclosure 17. The generator supplies the electric motor 29 with electrical energy from mechanical energy. For example, the generator draws mechanical energy from the fan shaft 11. For example, the generator is connected to the fan shaft 11 via a gear 30.

[0119] For example, the electric motor is controlled by a control unit 290. The control unit 290 regulates the speed of the auxiliary pump 28 via the electric motor. The control unit is, for example, a Fully Automatic Digital Engine Control (FADEC).

[0120] In another example, the auxiliary pump 28 is driven by the low-pressure shaft 10 .

[0121] The selective spraying device 26 comprises, for example, a selection member 27' and at least one spray head 27 arranged in the lubrication enclosure 17. The selection member 27' is, for example, a selection valve connected to the main circuit 24 and the auxiliary circuit 25.

[0122] The spray heads 27 make it possible to spray the lubricating oil into the lubricating enclosure 17. Advantageously, the selective spraying device 26 comprises two spray heads 27, a first spray head spraying the lubricating oil onto the reduction device 12 and a second spray head spraying the oil onto the gear 30. The spray heads are connected to the selection member 27' and are supplied with lubricating oil through one of the circuits 24, 25 depending on the position of the selection valve.

[0123] Now refer to Figures 6a to 6d and Figures 8a to 8d The operation of the main circuit 24 and the auxiliary circuit 25 will be described.

[0124] exist Figure 6a and Figure 8a In the first stage, the turbine engine 1 is stationary. Therefore, the main circuit 24 and the auxiliary circuit 25 are stopped. In this first stage, the auxiliary reservoir 31 contains the oil remaining from the previous flight.

[0125] exist Figure 6b and Figure 8b In the first nominal operating phase of the turbine engine 1 shown, the auxiliary circuit 25 is inactive, i.e. the auxiliary pump 28 is inactive. The main circuit 24 is active, i.e. the supply pump 240a is active and draws oil from the main reservoir 240b. The oil is delivered to the lubrication enclosure 17 via the main circuit 24. In this first phase, the lubricating oil flows by gravity into the bottom F of the enclosure and into the arm 20. Due to the deflector 22, the oil preferentially flows into the upstream compartment 21a, as indicated by the non-shaded arrow. The oil is stored in the auxiliary reservoir 31. During this phase, the amount of oil in the upstream compartment 21a is less than the maximum volume of the upstream compartment 21a. For example, the recovery pump 241a is also active. A small amount of oil that flows by gravity into the inner cavity 200 of the arm 20 can be extracted by the recovery pump 241a.

[0126] During this phase, there is a risk that the recovery pump 241a will extract a large amount of oil from the upstream compartment 21a, depending on the size of the recovery pump 241a. In order not to drain the oil from the upstream compartment 21a, Figure 8b In the second embodiment shown, the exhaust port 22c enables air to be drawn from the lubrication enclosure 17 by a recovery pump 241a, as shown by the shaded arrows.

[0127] exist Figure 6c and Figure 8c In the second nominal operation phase of the turbine engine 1 shown, the main circuit 24 is still active, but the amount of oil in the auxiliary reservoir 31 is greater than the maximum volume of the auxiliary reservoir 31 and the maximum volume of the upstream compartment 21a. The oil overflows into the downstream compartment 21b. In this second phase, the recovery pump 241a extracts oil from the downstream compartment 21b, thereby enabling the oil to circulate in the return circuit 241 of the main circuit 24 to supply the oil to the main reservoir 240b.

[0128] exist Figure 6d and Figure 8d In the third operating phase of the turbine engine 1 shown, for example in the case of free rotation of the fan 2 and the high-pressure shaft 10 stopped or under-speed, the pressure in the main circuit 24 decreases, so that the selection member 27 'becomes supplied by the auxiliary circuit 25 with a higher oil pressure. Then, when the auxiliary circuit 25 is active, the supply pump 240a is not activated or supplies an insufficient flow. The auxiliary pump 28 draws oil from the auxiliary reservoir 31, and the auxiliary pump 28 enables the oil to circulate in the auxiliary circuit 25 to lubricate the reduction device 12 in the lubricating enclosure 17. The recovery pump 241a can still rotate at a sufficient speed to allow the pump to suck a large amount of air from the upstream compartment 21a, as shown by the shaded arrows.

[0129] This air inhalation may cause cavitation damage to the recovery pump 241a.

[0130] In order to limit this risk of cavitation, Figure 4 In the particularly advantageous embodiment shown, the return circuit 241 comprises a hydraulic auxiliary valve 243 arranged between the arm 20 and the recovery pump 241a and a hydraulic anti-cavitation line 244 connected to the hydraulic outlet line 242b of the recovery pump 241a.

[0131] The auxiliary valve 243 includes a first inlet port 243a connected to the first oil outlet 20c of the arm 20, a second inlet port 243b connected to the hydraulic anti-cavitation line 244, and an outlet port 243c connected to the hydraulic inlet line 242a of the recovery pump 241a.

[0132] The auxiliary valve 243 also includes a member that can move between a first position and a second position, in which the outlet port 243c is in fluid communication with the first inlet port 243a, and in which the outlet port 243c is in fluid communication with the second inlet port 243b. In the first position, the recovery pump 241a draws oil from the downstream compartment 21b, and in the second position, the recovery pump 241a draws oil from the main reservoir 240b.

[0133] The auxiliary valve 243 is, for example, a spring-loaded valve.

[0134] Preferably, the auxiliary valve 243 has an electrical control system. For example, the auxiliary valve 243 is controlled by the control unit 290 .

[0135] Thus, when the turbine engine 1 is in the third operating phase (e.g., the fan 2 is free-spinning), the control unit 290 controls the auxiliary valve 243 in the second position. Thus, the recovery pump 241a can draw oil from the main reservoir 240b instead of drawing air from the downstream compartment 21b. Thus, this type of embodiment limits the risk of damage to the recovery pump 241a due to cavitation.

[0136] Thanks to the invention, it is possible to increase the volume of the auxiliary reservoir 31 without affecting the aerodynamic performance and the overall dimensions of the turbine engine 1 .

[0137] Thanks to the invention, when the supply pump 240a of the main circuit 24 stops, for example when the fan 2 rotates freely, it can be ensured that there is a sufficient amount of oil in the auxiliary reservoir 31 for lubricating the reduction device 12 in the lubricating enclosure 17.

[0138] Thanks to an advantageous embodiment of the invention, it is possible to supply the upstream compartment 21a despite the nose of the aircraft being maneuvered upwards.

[0139] Due to the advantageous embodiment of the invention, the risk of oil escaping from the upstream compartment 21 a into the lubrication enclosure 17 in the event of a nose-down maneuver of the aircraft is reduced.

Claims

1. A turbine engine (1) for an aircraft, the turbine engine extending about a longitudinal axis (X) and comprising: - a fan (2) driven in rotation about said longitudinal axis (X) by a fan shaft (11), - a low-pressure shaft (10) connected to the fan shaft via a mechanical reduction device (12), - an annular lubricating enclosure (17), in which the reduction device (12) is arranged, a lubrication system for lubricating the reduction gear (12), the lubrication system comprising a main lubrication circuit (24) and an auxiliary lubrication circuit (25) connected to the lubrication enclosure (17), the auxiliary circuit (25) being connected to an auxiliary reservoir (31), - an air intake housing (8) comprising an inner shroud (19) and an outer shroud (18) centered on the longitudinal axis (X) and connected by an arm, the inner shroud (19) extending around the lubrication enclosure (17), the auxiliary reservoir (31) being located outside the outer shroud (18), one of the arms, referred to as the 6 o'clock arm (20), being tubular and located at the 6 o'clock position, the 6 o'clock arm (20) comprising: a radially outer end portion (20b) and an opposite radially inner end portion (20a), the radially outer end portion being connected to the outer shroud (18), an inner cavity (200) which leads to the lubricating enclosure (17) via an oil inlet (200a), a first oil outlet (20c), the first oil outlet being connected to the main circuit (24), a second oil outlet (20d) connected to the auxiliary reservoir (31), the first and second oil outlets (20c, 20d) being diametrically opposed to the oil inlet (200a), and a radial baffle (21) arranged in the inner cavity (200) and defining an upstream compartment (21a) and a downstream compartment (21b), the second outlet (20d) being located in the upstream compartment (21a), the first outlet (20c) being located in the downstream compartment (21b), Characterized in that the lubrication enclosure (17) further comprises a deflector (22) connected to the radially inner end (20a) of the 6 o'clock arm (20) and configured to deflect oil flowing from the lubrication enclosure (17) towards the upstream compartment (21a) by gravity.

2. Turbine engine according to the preceding claim, characterized in that The deflector (22) includes an axial wall (22a) connected to the 6 o'clock arm (20) and the inner shroud (19), the axial wall (22a) having a flow surface inclined toward the inner cavity (200) so that the axial wall (22a) continuously moves away from the longitudinal axis (X) as it advances upstream of the 6 o'clock arm (20).

3. A turbine engine according to any one of the preceding claims, characterised in that The 6 o'clock arm (20) comprises axially opposed upstream and downstream walls (201, 202) extending radially between the inner and outer ends (20a, 20b), the oil inlet (200a) being axially bounded by an edge (22b) of the deflector (22) and the upstream wall (201) of the 6 o'clock arm (20).

4. A turbine engine according to any one of the preceding claims, characterised in that The circumferential width of the deflector (22) is equal to the circumferential width of the 6 o'clock arm (20).

5. A turbine engine according to any one of the preceding claims, characterised in that The passage cross section (S1) of the oil inlet (200a) is equal to or larger than the passage cross section (S2) of the first oil outlet (20c).

6. A turbine engine according to any one of the preceding claims, characterised in that The radially outer end portion (20b) of the 6 o'clock arm (20) has a bottom wall (20b'), the second oil outlet (20d) is formed in the bottom wall, and the partition plate (21) radially extends from the bottom wall (20b') toward the inside of the 6 o'clock arm (20).

7. A turbine engine according to any one of the preceding claims, characterised in that A separation barrier (23) is arranged in the inner cavity (200) and extends radially from the deflector (22) at least to the second oil outlet (20d).

8. Turbine engine according to the preceding claim, characterized in that An exhaust port (22c) is formed in the deflector (22) and opens into the lubrication enclosure (17) and the inner cavity (200) on the side of the downstream compartment (21b).

9. A turbine engine according to any one of the preceding claims, characterised in that The auxiliary reservoir (31) is directly connected to the second oil outlet (20d).

10. A turbine engine according to any one of the preceding claims, characterised in that The auxiliary reservoir (31) is housed in a venous compartment (1c) which divides the air flow (F) generated by the fan (2) into a primary flow (F1) and a secondary flow (F2).

11. A turbine engine according to any one of the preceding claims, characterised in that The main circuit (24) comprises: a recovery pump (241a) having a hydraulic inlet line (242a) and a hydraulic outlet line (242b), - a hydraulic anti-cavitation line (244) connected to the hydraulic outlet line (242b) of the recovery pump (241a), and - a hydraulic auxiliary valve (243), which is arranged between the recovery pump (241a) and the arm (20), and the auxiliary valve (243) comprises: a first inlet port (243a), the first inlet port being connected to the first oil outlet (20c), a second inlet port (243b) connected to the hydraulic anti-cavitation line (244), an outlet port (243c) connected to the hydraulic inlet line (242a) of the recovery pump (241a), and A member movable between a first position in which the outlet port (243c) is in fluid communication with the first inlet port (243a) and a second position in which the outlet port (243c) is in fluid communication with the second inlet port (243b).

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