Housing for aircraft turbine engine

Abstract

The invention relates to a housing (8) comprising:-an inner annular shell part (19) and an outer annular shell part (18), the inner annular shell part defining a lubrication enclosure (17) internally; -an arm extending radially between the inner and outer annular shells (19, 18), the arm comprising an inner cavity (200) provided with a first compartment (21a) leading to the lubrication enclosure (17) through an oil inlet (200a) provided in the inner shell (19), and a second compartment (21b) separated from the lubrication enclosure (17) by a cover (22), the cover extends longitudinally within the lubrication enclosure (17) from the second annular edge (19b) of the inner annular shell portion (19) to the oil inlet (200a), where the oil inlet (200a) is circumferentially delimited on either side of the oil inlet (200a) by first and second walls (23a, 23b) extending radially from the inner shell portion (19).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of a casing for a turbine engine of an aircraft.

[0002] More particularly, the present invention relates to the field of a casing defining a lubrication enclosure for a turbine engine comprising a lubrication system for a reduction gear, the lubrication system comprising a main lubrication circuit and an auxiliary lubrication circuit. BACKGROUND

[0003] Document US-A1-2006 / 042223 describes the state of the art.

[0004] An aircraft turbine engine generally comprises, in the gas flow direction from upstream to downstream, a fan, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine and a gas discharge nozzle, in rotation around a longitudinal axis.

[0005] The fan makes it possible to draw in an air flow which is divided into a primary flow and a secondary flow. The primary flow passes through a main channel of the turbine engine, while the secondary flow is directed towards a secondary channel which surrounds the main channel.

[0006] The turbine engine also comprises an inlet casing which is centred on the longitudinal axis and which defines an inlet of the main channel. The inlet casing comprises an annular inner casing portion which is surrounded by an annular outer casing portion, the annular inner casing portion and the annular outer casing portion being connected by radial arms.

[0007] The primary flow is compressed in the compressor downstream. 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 then through the nozzle, the cross section of which makes it possible to accelerate these gases to produce a propulsive force.

[0008] The rotor of the low-pressure turbine is connected to the rotor of the low-pressure compressor by a low-pressure shaft, the rotor of the high-pressure turbine being connected to the rotor of the high-pressure compressor by a high-pressure shaft. Furthermore, the fan is driven in rotation by a fan shaft which is connected to the low-pressure shaft by a reduction gear, making it possible to drive the fan at a lower rotational speed than that of the low-pressure shaft. The reduction gear is generally arranged in a lubrication enclosure for lubricating the reduction gear. The lubrication enclosure is generally located inside the inner casing portion.

[0009] In order to ensure the lubrication of the reduction gear in the lubrication enclosure, the turbine engine also comprises a main lubrication circuit of the reduction gear connected to the lubrication enclosure. The main circuit comprises an oil supply pump of the reduction gear connected to a main oil reservoir. The oil supply pump is generally driven in rotation by the high-pressure shaft through an accessory gearbox.

[0010] During some operating phases of the turbine engine, for example the free rotation phase of the fan, known as "windmilling" (during which the fan shaft is driven in rotation so as to drive the low pressure shaft), the rotation speed of the high pressure shaft is not sufficient to drive the supply pump at a speed sufficient to provide the flow required for lubricating the reduction gear. However, it is necessary to ensure lubrication of the reduction gear even during these operating phases of the turbine engine.

[0011] In this case, the turbine engine comprises an auxiliary lubrication circuit for the reduction gear. The auxiliary circuit generally comprises an auxiliary pump, for example supplied with energy by the generator or driven by the low pressure shaft, which makes it possible to start the auxiliary pump even in the case of free rotation of the fan and low rotation speed of the high pressure shaft.

[0012] To supply the auxiliary circuit with oil, the document FR-A1-3 075 875 proposes to recover the oil which flows by gravity into the bottom of the enclosure. To do this, one radial arm, located at the 6 o'clock position, has an inner cavity which opens into the enclosure through an oil inlet. The arm also has a first oil outlet connected to the main circuit through a first duct and a second oil outlet connected to the auxiliary circuit through a second duct. The first duct is connected to an oil recovery pump which supplies the main reservoir and the second duct is connected to an auxiliary pump in the auxiliary circuit.

[0013] Furthermore, according to this document, a radial partition is arranged in the inner cavity and delimits an upstream compartment and a downstream compartment, the second duct being connected to the upstream compartment and the first duct being connected to the downstream compartment.

[0014] Thus, for example, during the free rotation phase of the fan, when the supply pump is not started, the auxiliary pump sucks in the oil which flows by gravity into the arm located at the 6 o'clock position through the second duct. Thus, the auxiliary circuit can be supplied with oil to lubricate the reduction gear during these phases.

[0015] Although this solution provides a volume of oil for the auxiliary lubrication of the reduction gear in the case of free rotation of the fan, however, the volume of oil which can be used for these operating phases can be increased. Indeed, this document teaches that, in order to maximize the recovery of oil, the oil inlet has a maximum axial dimension which is defined between the upstream edge and the downstream edge of the arm and extends over the entire axial width of the arm. The combination of the oil inlet configuration and the radial wall hinders optimal recovery of oil in the first duct. Indeed, the oil which flows by gravity down the arm supplies the upstream compartment and the downstream compartment. Thus, even if the auxiliary circuit does not have the maximum volume during the free rotation phase of the fan, the main circuit can still be supplied with oil. During these phases, although the lubrication of the reduction gear is ensured, the lubrication of the reduction gear can be optimized.

[0016] There is therefore a need to provide a solution for optimizing the lubrication of the reduction gear during all operating phases of the turbine engine. SUMMARY

[0017] To this end, the application proposes a casing for a turbine engine of an aircraft, the casing extending around a longitudinal axis and comprising: - an inner annular shell portion centered on the longitudinal axis and internally defining a lubrication enclosure, the inner annular shell portion having axially opposite first and second annular edges, - an outer annular shell portion arranged coaxially around the inner annular shell portion, - arms extending radially between the inner and outer annular shell portions, one of the arms, referred to as the 6 o'clock position arm, being tubular and located at the 6 o'clock position, the 6 o'clock position arm comprising: - a radially outer end connected to the outer shell portion and a radially inner end connected to the inner shell portion, - an inner cavity comprising a first compartment and a second compartment, the first compartment opening onto the lubrication enclosure via an oil inlet provided in the inner shell portion, - a first oil outlet located in the second compartment, - a second oil outlet located in the first compartment, the first and second oil outlets being radially offset from the radially inner end.

[0018] The casing according to the application is particularly characterized in that the second compartment is separated from the lubrication enclosure by a cover extending longitudinally in the lubrication enclosure from the second annular edge toward the oil inlet, and in that the oil inlet is circumferentially delimited on both sides of the oil inlet by first and second walls extending radially from the inner shell portion.

[0019] Thanks to the cover separating the second compartment of the 6 o'clock position arm from the first compartment of the 6 o'clock position arm, in combination with the first and second walls delimiting the oil inlet, the oil flows into the first compartment in a preferential manner, the first compartment being configured to be connected to an auxiliary reservoir of an auxiliary lubrication circuit.

[0020] The auxiliary reservoir is therefore preferentially supplied with oil, which ensures the lubrication of the reduction gear when the auxiliary circuit is in operation.

[0021] Thanks to the casing of the application, a greater volume of oil can be stored in the auxiliary reservoir to supply the auxiliary circuit. The reduction gear can therefore be optimally, reliably and efficiently lubricated during all operating phases of the turbine engine.

[0022] The application can include one or more of the following features taken individually or in combination with each other: - the first and second walls extend longitudinally in the inner shell portion from the first annular edge to the second annular edge, - the oil inlet is axially delimited by a third wall, the third wall being located between the first and second walls and extending radially into the first compartment, - the third wall extends radially to the second oil outlet, - the first and second grooves are arranged on either side of the first and second walls and are configured to transport oil from the lubrication enclosure towards the oil inlet, - the first and second grooves extend over an angular sector of between 5° and 10° around the longitudinal axis, - the 6 o'clock position arm comprises a radial partition arranged in the inner cavity and separating the first compartment from the second compartment, - the radially outer end of the 6 o'clock position arm has a bottom wall in which the second oil outlet is provided, the partition extending radially from the bottom wall towards the interior of the 6 o'clock position arm.

[0023] The application also relates to a turbine engine for an aircraft, the turbine engine comprising a casing according to any one of the preceding characteristics.

[0024] The turbine engine can comprise one or more of the following characteristics taken separately or in combination: - a fan, the fan being driven in rotation around the longitudinal axis by a fan shaft, - a low-pressure shaft connected to the fan shaft by a mechanical reduction gear arranged in the lubrication enclosure, - a lubrication system for lubricating the reduction gear, the lubrication system comprising a main lubrication circuit and an auxiliary lubrication circuit, the main lubrication circuit and the auxiliary lubrication circuit being connected to the lubrication enclosure of the casing, the auxiliary circuit being connected to an auxiliary reservoir, the auxiliary reservoir being located outside the outer shell portion of the casing, the first oil outlet being connected to the main circuit, the second oil outlet being connected to the auxiliary reservoir, - the auxiliary reservoir being directly connected to the second oil outlet of the casing, - the auxiliary reservoir being housed in a channel compartment, the channel compartment being configured to divide the air flow generated by the fan into a primary flow and a secondary flow, - the channel compartment being radially located between a primary flow channel for the primary flow and a secondary flow channel for the secondary flow. BRIEF DESCRIPTION OF DRAWINGS

[0025] Other features and advantages will become apparent from the following description of non-limiting embodiments of the application, with reference to the attached drawings, in which: Figure 1 is a longitudinal cross-sectional view of an aircraft turbine engine according to the application, Figure 2 is a longitudinal cross-sectional view of an aircraft turbine engine according to the application, Figure 1a longitudinal cross-sectional view of a reduction gear of a turbo engine, Figure 3 a lubrication system of a reduction gear according to an example of an embodiment of the application, Figure 2 a schematic view of a lubrication system of a reduction gear, Figure 4 a schematic perspective view of a housing according to the application, Figure 5 a further schematic perspective view of a housing shown in Figure 4 Figure 6 longitudinal cross-sectional views of a housing shown in Figure 4 and Figure 5 . DETAILED DESCRIPTION

[0026] An example of an aircraft turbo engine 1 according to the application is shown in Figure 1 . The turbo engine 1 extends around and along a longitudinal axis X.

[0027] In the present application, the terms "axial", "axially", "radial" and "radially" are defined with respect to the longitudinal axis X.

[0028] The terms "upstream" and "downstream" are defined with respect to the direction of the gas flow along the longitudinal axis X in the turbo engine 1.

[0029] The terms "internal", "in", "external", "out", and "outward" are defined with respect to the distance from the longitudinal axis X along a radial axis Z perpendicular to the longitudinal axis X.

[0030] The turbo engine 1 comprises, from upstream to downstream, a fan 2, at least one compressor (for example a low-pressure compressor 3 and a high-pressure compressor 4), a combustion chamber 5, at least one turbine (for example a high-pressure turbine 6 and a low-pressure turbine 7), and a nozzle for the exhaust.

[0031] The fan 2 makes it possible to draw in an air flow F which is divided into a primary flow F1 and a secondary flow F2. The primary flow F1 passes through a primary channel la of the turbo engine 1, while the secondary flow F2 is directed towards a secondary channel lb surrounding the primary channel la.

[0032] The primary 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. The gases are finally expelled through the nozzle, the cross section of which makes it possible to accelerate these gases to produce a propulsive force.

[0033] The fan 2 is in rotational movement around the longitudinal axis X. The fan 2 comprises blades 2a distributed uniformly around a disc centered on the longitudinal axis X.​

[0034] The fan 2 is, for example, ducted. Therefore, the turbine engine 1 includes an annular nacelle 2b surrounding the fan 2, centered on the longitudinal axis X. The nacelle 2b is supported, for example, by the fan casing (not shown).

[0035] The turbine engine 1 also includes a casing 8. The casing 8 is, for example, an inlet casing. The casing 8 is, for example, located inside the nacelle 2b. The casing 8 is, for example, axially arranged between the fan 2 and the low-pressure compressor 3. The casing 8 forms an inlet port for the main passage 1a. The casing 8 includes an annular outer casing portion 18 and an annular inner casing portion 19 arranged within the outer casing portion 18. The outer casing portion 18 and the inner casing portion 19 are connected about a longitudinal axis X by a radial arm. Each of the outer casing portion 18 and the inner casing portion 19 has a first annular edge 18a, 19a (particularly upstream annular edges 18a, 19a) and a second annular edge 18b, 19b (particularly downstream annular edges 18b, 19b). The first annular edges 18a, 19a and the second annular edges 18b, 19b are axially opposite each other.

[0036] The main channel 1a is defined downstream of the inlet port by the inner shell 110, which is arranged downstream of the outer shell 18 and the inner shell 19.

[0037] The secondary passageway 1b is further defined radially by nacelle 2b and inter-passage hull 180, which is arranged radially between nacelle 2b and hull 8.

[0038] Furthermore, the channel compartment 1c is radially arranged between the secondary channel 1b and the main channel 1a. The channel compartment 1c has a first region Z1, which is defined internally by the outer shell portion 18 and externally by the inter-channel housing 180. The channel compartment 1c includes a second region Z2 located downstream of the first region Z1.

[0039] exist Figure 1 In the specific 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 within the high-pressure shaft 9 and extends along the longitudinal axis X.

[0040] The low-pressure shaft 10 is guided to rotate by a bearing. For example, an intermediate bearing 10a is arranged radially between the low-pressure shaft 10 and a first bearing support 10b, which is connected, for example, to the inner housing 19. The intermediate bearing 10a is, for example, a ball bearing.

[0041] The fan 2 is driven in rotation by a fan shaft 1 1. The fan shaft 1 1 is connected to the disc to drive it in rotation. The fan shaft 1 1 is supported by a downstream bearing 1 1 a arranged radially between the fan shaft 1 1 and a second bearing support 1 1 b connected to the inner casing portion 19. The downstream bearing 1 1 a is for example a ball bearing. The downstream bearing is located upstream of the intermediate bearing 10a. The downstream bearing 1 1 a is arranged at a downstream end of the fan shaft 1 1.

[0042] The fan shaft 1 1 is also connected to the low pressure shaft 10 by means of a reduction gear 12. The reduction gear 12 is mechanical.

[0043] As best seen in Figure 2 The reduction gear 12 comprises a sun gear 13, a ring gear 14, at least one planet gear 15 meshing with the ring gear 14 and the sun gear 13, and a planet carrier 16.

[0044] The sun gear 13 is rotationally coupled with the low pressure shaft 10. The sun gear forms an inlet portion of the reduction gear 12.

[0045] The reduction gear 12 advantageously comprises a plurality of planet gears 15. Each planet gear 15 has a central axis X' parallel to the longitudinal axis X.

[0046] The ring gear 14 is annular and arranged around the longitudinal axis X. According to the example in Figure 1 The ring gear 14 is rotationally coupled with the fan shaft 1 1. The ring gear 14 comprises for example an attachment flange 14a connected to the fan shaft 1 1 by means of attachment bars 14b such as screws for example. The ring gear 14 forms an outlet portion of the reduction gear 12.

[0047] The planet carrier 16 is fixed around the longitudinal axis X without rotation. The planet carrier 16 is connected to a fixed structure of the turbine engine 1. As shown in the example in Figure 2 The planet carrier 16 is connected to the inner casing portion 19 for example via a flexible support 1 1 c.

[0048] The reduction gear 12 is made of gears and rolling bearings which require lubrication. To this end, lubricating oil is injected onto the reduction gear 12. In order to protect other components of the turbine engine 1 from this oil, the reduction gear 12 is arranged in an annular lubrication enclosure 17. The lubrication enclosure 17 is for example an upstream enclosure. The lubrication enclosure 17 is located inside the inner casing portion 19. The lubrication enclosure 17 is therefore delimited by the inner casing portion 19. The lubrication enclosure can contain the upstream bearing 1 1 a and the intermediate bearing 10a.

[0049] The lubrication enclosure 17 has an enclosure bottom F. The enclosure bottom F is located at the lowest point of the lubrication enclosure 17, i.e. at the lowest point of the inner casing portion 19. The lubricating oil flows by gravity into the enclosure bottom F.

[0050] With reference toFigure 3 Among the radial arms extending radially between the outer housing portion 18 and the inner housing portion 19, the tubular arm 20 is located at the 6 o'clock position, by analogy with the corresponding position on a clock face. For the sake of simplicity, this 6 o'clock position arm (6h arm) will be referred to as the "arm" in the remainder of the description.

[0051] The arm 20 comprises a radially inner end portion 20a connected to the inner housing portion 19, in particular to the lubricating enclosure 17, in particular to the enclosure bottom F. The radially inner end portion 20a is, for example, open. The arm 20 also comprises a radially outer end portion 20b connected to the outer housing portion 18 and opposite the radially inner end portion 20a. The radially outer end portion 20b has, for example, a bottom wall 20b' formed preferably by the outer housing portion 18.

[0052] The arm 20 also has a first face and a second face opposite each other and extending radially between the radially outer end portion 20b and the radially inner end portion 20a. Advantageously, the first face and the second face extend axially between the annular edges of the outer housing portion 18 and the inner housing portion 19. The first face and the second face meet at a first edge 201, in particular an upstream edge 201, and at a second edge 202, in particular a downstream edge 202. The upstream edge 201 and the downstream edge 202 are axially connected to each other at their outer end portions by the bottom wall 20b'.

[0053] The arm 20 also comprises an inner cavity 200 comprising a first compartment 21a, in particular an upstream compartment 21a, and a second compartment 21b, in particular a downstream compartment 21b. According to a preferred embodiment of the application, the arm 20 comprises a radial partition 21 arranged in the inner cavity 200 and separating the first compartment 20a and the second compartment 20b. The radial partition 21 extends, for example, radially inwardly from the bottom wall 20b'. The first compartment 21a and the second compartment 21b each have a predetermined volume.

[0054] The first compartment 21a opens into the lubricating enclosure 17 via an oil inlet 200a. Thus, lubricating oil can flow by gravity from the lubricating enclosure 17 into the arm 20. The oil inlet 200a is, for example, provided in the inner housing portion 19 and opens into the first compartment 21a.

[0055] Reference is made to Figure 4 and Figure 5According to the application, the oil inlet 200a is circumferentially delimited by the first wall 23a and the second wall 23b around the longitudinal axis X. The first wall 23a and the second wall 23b are arranged on either side of the oil inlet 200a. The first wall 23a and the second wall 23b are located in the inner shell portion 19 and extend radially from the inner shell portion 19. The first wall and the second wall extend radially inwards from the inner shell portion 19. For example, the first wall and the second wall form an integral piece with the inner shell portion 19. The inner shell portion 19 and the first wall 23a and the second wall 23b are made integrally.

[0056] Preferably, the first wall 23a and the second wall 23b extend radially in the extension of the arm 20, i.e. in the extension of the first face and the second face of the arm 20. The first wall 23a and the second wall 23b extend longitudinally in the inner shell portion 19. The first wall and the second wall extend between the first annular edge 19a and the second annular edge 19b, preferably from the first annular edge 19a to the second annular edge 19b of the inner shell portion 19. The first wall 23a and the second wall 23b are parallel to each other. The first wall 23a and the second wall 23b have a height hi measured along the radial axis Z which is preferably equal.

[0057] With reference to Figure 4 to Figure 6 According to a preferred embodiment of the application, the oil inlet 200a is axially delimited by a third wall 23c. The third wall 23c is arranged between the first wall 23a and the second wall 23b. The third wall extends radially inwards from the inner shell portion 19 and is perpendicular to the first wall 23a and the second wall 23b. The third wall 23c extends radially into the first compartment 21a. The third wall is located upstream of the partition 21.

[0058] According to the application, the second compartment 21b is separated from the lubrication enclosure 17 by the cover 22. The cover 22 thus enables the second compartment 21b to be closed at the inner end of the second compartment, so that oil only flows into the first compartment 21a.

[0059] The cover 22 extends longitudinally from the second annular edge 19b into the lubrication enclosure 17 towards the oil inlet 200a. The cover 22 thus has an upstream end 22a located on the same side as the oil inlet 200a and an axially opposite downstream end 22b. The third wall 23c is thus axially offset downstream relative to the upstream end 22a of the cover 22. This further reduces the risk of oil leaking from the lubrication enclosure 17 into the second compartment 21b.

[0060] In a preferred embodiment of the application, the cover 22 is fixed to the first wall 23a and to the second wall 23b. The cover 22 is bolted to the first wall 23a and to the second wall 23b. For example, lugs 23c protrude from the first wall 23a and from the second wall 23b. The lugs 23c of the first wall 23a face the lugs 23c of the second wall 23b. The lugs 23c of the first wall 23a and of the second wall 23b are for example staggered. The cover 22 is connected to the lugs 23c by means of bolts 22c.

[0061] Advantageously, the circumferential width of the cover 22 is equal to the circumferential width of the arm 20. The cover 22 extends circumferentially between the first face and the second face of the arm 22. This prevents the oil from flowing into the second compartment 21b by gravity.

[0062] According to a preferred embodiment of the application, the casing 8 further comprises a first groove 32a and a second groove 32b arranged on both sides of the first wall 23a and of the second wall 23b. The first groove 32a and the second groove 32b are configured to transport the oil from the lubrication enclosure 17 towards the oil inlet 200a and thus to facilitate the flow of oil into the first compartment 21a. The first groove 32a and the second groove 32b extend from the first wall 23a and from the second wall 23b, opposite the second annular edge 19b of the inner casing 19. Thus, the first groove and the second groove are located on the side of the oil inlet 200a. The first groove 32a and the second groove 32b extend over an angular sector of between 5° and 10° around the longitudinal axis X.

[0063] With reference to Figure 3 , the arm 20 further comprises a first oil outlet 20c and a second oil outlet 20d radially opposite the oil inlet 200a. For example, the first oil outlet and the second oil outlet are provided in the bottom wall 20b' and / or in the downstream edge 202. The first outlet 20c is for example provided in the downstream edge 202 and the second outlet 20d is for example provided in the bottom wall 20b'.

[0064] The first outlet 20c is located in the second compartment 21b, i.e. the downstream compartment 21b, and the second outlet 20d is located in the first compartment 21a, i.e. the upstream compartment 21a. Preferably, the third wall 23c extends up to the second outlet 20d.

[0065] To ensure the lubrication of the reduction gear 12 in the lubrication enclosure 17, the turbine engine 1 comprises a lubrication system for lubricating the reduction gear 12.

[0066] The lubrication system comprises a main lubrication circuit 24 and an auxiliary lubrication circuit 25, the main circuit 24 and the auxiliary circuit 25 being connected to the lubrication enclosure 17. The lubrication system 23 can also comprise a selective injection device 26 for injecting lubricating oil into the lubrication enclosure 17, the selective injection device 26 being connected to the main circuit 24 and to the auxiliary circuit 25.

[0067] The main circuit 24 generally comprises a supply circuit 240 connecting the main reservoir 240b to the lubrication enclosure 17. The supply circuit 240 comprises a supply pump 240a mounted 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 for example mechanically driven by the high-pressure shaft 9. Advantageously, the supply pump 240a is connected to the high-pressure shaft 9 through an accessory gearbox (AGB). The accessory gearbox is for example housed in the tunnel compartment 1c. Thus, when the high-pressure shaft 9 is driven in rotation, it activates the supply pump 240a which sucks oil from the main reservoir 240b and supplies it to the selective injection device 26. The supply circuit 240 can also comprise at least one air / oil exchanger 240c arranged for example between the selective injection device 26 and the supply pump 240a.

[0068] The main circuit 24 also comprises a return circuit 241 connecting the main reservoir 240b to the second compartment 21b of the arm 20. The return circuit 241 comprises a recovery pump 241a advantageously located in the tunnel 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.

[0069] In some cases, the high-pressure shaft 9 is not driven in rotation, or is driven at a rotational speed that is not sufficient to drive the supply pump 240a in rotation. For example, when the fan 2 is in a free-rotation state (or automatic-rotation state, also called "windmilling"), or during the start-up or shutdown phases of the turbomachine 1, the supply pump 240a is not activated and can no longer supply oil to the selective injection device 26. The reducer 12 is thus no longer lubricated by the main circuit 24. In this case, the lubrication of the reducer 12 is provided by the auxiliary circuit 25.

[0070] The auxiliary circuit 25 is a closed lubrication circuit of the lubrication enclosure 17. The auxiliary circuit comprises an auxiliary pump 28 connected to the auxiliary reservoir 31 and to the lubrication enclosure 17, in particular to the selective injection device 26.

[0071] The auxiliary reservoir 31 is located outside the housing part 18. Preferably, the auxiliary reservoir 31 is located in the tunnel compartment 1c, for example in the first zone Z1. Since the auxiliary reservoir 31 is located outside the main tunnel 1a, it can have a large content volume without affecting the aerodynamic performance of the turbomachine 1. This means that a large volume of oil can be stored.

[0072] 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 with the first compartment 21a. The oil that flows by gravity into the first compartment 21a is stored in the auxiliary reservoir 31.

[0073] Thanks to the cover 22 of the application, the auxiliary reservoir 31 is filled first. The risk of oil shortage for the auxiliary reservoir 31 is limited. This ensures that the reduction gear 12 is optimally and reliably lubricated whatever the operating phase of the turbine engine 1.

[0074] Preferably, the auxiliary reservoir 31 is directly connected with the second oil outlet 20d of the arm 20.

[0075] The auxiliary pump 28 is driven, for example, by an electric motor 29. The auxiliary pump 28 and the electric motor 29 are, for example, located in the passage compartment 1c. The electric motor 29 is supplied with electrical energy by an electric generator (not shown) located, for example, in the lubrication enclosure 17. The electric generator supplies the electric motor 29 with electrical energy from mechanical energy. For example, the electric generator takes the mechanical energy from the fan shaft 11. For example, the electric generator is connected to the fan shaft 11 by a gear 30.

[0076] The electric motor is controlled, for example, by a control unit 290. The control unit 290 makes it possible to adjust the speed of the auxiliary pump 28 via the electric motor. For example, the control unit is a Full Automatic Digital Engine Control (FADEC).

[0077] In another example, the auxiliary pump 28 is driven by the low-pressure shaft 10.

[0078] The selective injection device 26 comprises, for example, a selection member 27' and at least one sprayer 27 arranged in the lubrication enclosure 17. The selection member 27' is, for example, a selection valve connected to the main circuit 24 and to the auxiliary circuit 25.

[0079] The sprayers 27 make it possible to inject lubricating oil into the lubrication enclosure 17. The selective injection device 26 advantageously comprises two sprayers 27, namely a first sprayer that injects lubricating oil onto the reduction gear 12 and a second sprayer that injects oil onto the gear 30. The sprayers are connected to the selection member 27' and are supplied with lubricating oil by one of the circuits 24, 25 depending on the position of the selection valve.

[0080] The operation of the main circuit 24 and of the auxiliary circuit 25 will now be described.

[0081] In a first operating phase, the turbine engine 1 is in a stationary state. The main circuit 24 and the auxiliary circuit 25 are therefore stopped. In this first phase, the auxiliary reservoir 31 comprises the oil remaining from the previous flight.

[0082] At a first nominal operating phase of the turbine engine 1, the auxiliary circuit 25 is not operating, i.e. the auxiliary pump 28 is not operating. The main circuit 24 is operating, i.e. the supply pump 240a is operating and oil is taken from the main reservoir 240b. The oil is delivered to the lubrication enclosure 17 via the main circuit 24. At this first phase, the lubricating oil flows by gravity into the enclosure bottom F and into the arm 20. Due to the cover 22, the oil preferentially flows into the first compartment 21a. This oil is stored in the auxiliary reservoir 31. At this phase, the volume of oil in the first compartment 21a is less than the maximum volume of the first compartment 21a. The recovery pump 241a is also operating, for example.

[0083] At a second nominal operating phase of the turbine engine 1, the main circuit 24 is still operating, but the volume of oil in the auxiliary reservoir 31 is greater than the maximum volume of the auxiliary reservoir 31 and the maximum volume of the first compartment 21a. The oil is delivered into the second compartment 21b, for example by overflow. At this second phase, the recovery pump 241a sucks oil from the second compartment 21b and enables the circulation of oil in the return circuit 241 of the main circuit 24 to supply the main reservoir 240b with oil.

[0084] At a third operating phase of the turbine engine 1, for example in case of free rotation of the fan 2 and stop or insufficient rotation of the high pressure shaft 10, the pressure in the main circuit 24 decreases so that the selection member 27' becomes supplied by the auxiliary circuit 25 which has a higher oil pressure. Then, the supply pump 240a is stopped or supplies a deficient flow, while the auxiliary circuit 25 is operating. The auxiliary pump 28 takes oil from the auxiliary reservoir 31 and enables the circulation of oil in the auxiliary circuit 25 to lubricate the reduction gear 12 in the lubrication enclosure 17.

[0085] Thanks to the invention, it is possible to increase the volume of the auxiliary reservoir 31 without affecting the aerodynamic performance and the overall size of the turbine engine 1.

[0086] Thanks to the invention, in case of stop of the supply pump 240a of the main circuit 24, for example in case of free rotation of the fan 2, it is possible to guarantee an optimum amount of oil in the auxiliary reservoir 31 to lubricate the reduction gear 12 in the lubrication enclosure 17.

Claims

1. A housing (8) for an aircraft turbine engine (1), the housing (8) extending about a longitudinal axis (X), and comprising: - Inner annular shell portion (19), which is centered on the longitudinal axis (X) and defines a lubricating enclosure portion (17) inside, the inner annular shell portion (19) having an axially opposite first annular edge and a second annular edge (19a, 19b). -Outer annular shell portion (18), which is arranged coaxially around the inner annular shell portion (19). - An arm, which extends radially between the inner annular shell portion and the outer annular shell portion (19, 18), one of the arms, referred to as the 6 o'clock position arm (20), is tubular and located at the 6 o'clock position, the 6 o'clock position arm (20) comprising: Radial outer end (20b) and radial inner end (20a), the radial outer end being connected to the outer shell portion (18), and the radial inner end being connected to the inner shell portion (19). The inner cavity (200) includes a first compartment (21a) and a second compartment (21b), the first compartment being connected to the lubrication enclosure (17) via an oil inlet (200a) disposed in the inner shell portion (19). The first oil outlet (20c) is located in the second compartment (21b). A second oil outlet (20d) is located within the first compartment (21a), and the first and second oil outlets (20c, 20d) are radially offset from the radially inner end (20a). The second compartment (21b) is separated from the lubrication enclosure (17) by a cover (22), the cover extending longitudinally from the second annular edge (19b) toward the oil inlet (200a) in the lubrication enclosure (17), and the oil inlet (200a) is circumferentially defined on both sides by a first wall and a second wall (23a, 23b) extending radially from the inner shell (19).

2. The housing according to the preceding claim, characterized in that, The first wall and the second wall (23a, 23b) extend longitudinally from the first annular edge (19a) to the second annular edge (19b) in the inner shell portion (19).

3. The housing according to any one of the preceding claims, characterized in that, The oil inlet (200a) is axially defined by a third wall (23c) located between the first wall and the second wall (23a, 23b) and extending radially into the first compartment (21a).

4. The housing according to the preceding claim, characterized in that, The wall (23c) extends radially to the second oil outlet (20d).

5. The housing according to any one of the preceding claims, characterized in that, The housing includes a first groove and a second groove (32a, 32b) arranged on both sides of the first wall and the second wall (23a, 23b), the first groove and the second groove being configured to deliver oil from the lubrication enclosure (17) toward the oil inlet (200a).

6. The housing according to the preceding claim, characterized in that, The first slot and the second slot (32a, 32b) extend around the longitudinal axis (X) in an angular sector between 5° and 10°.

7. The housing according to any one of the preceding claims, characterized in that, The 6 o'clock position arm (20) includes a radial partition (21) arranged in the inner cavity (200) and separating the first compartment (21a) from the second compartment (21b).

8. The housing according to the preceding claim, characterized in that, The radially outer end (20b) of the 6 o'clock position arm (20) has a bottom wall (20b'), in which the second oil outlet (20d) is disposed, and the partition (21) extends radially from the bottom wall (20b') toward the interior of the 6 o'clock position arm (20).

9. A turbine engine (1) for an aircraft, characterized in that, The turbine engine includes a housing (8) according to any one of the preceding claims.

10. The turbine engine according to the preceding claim, characterized in that, The turbine engine also includes: - Fan (2), the fan being driven by fan shaft (11) to rotate about the longitudinal axis (X), - Low-pressure shaft (10), which is connected to the fan shaft via a mechanical reducer (12) arranged in the lubrication enclosure (17). - A lubrication system for lubricating the reducer (12), the lubrication system including a main lubrication circuit (24) and an auxiliary lubrication circuit (25), the main lubrication circuit and the auxiliary lubrication circuit being connected to the lubrication enclosure (17) of the housing (8), the auxiliary circuit (25) being connected to an auxiliary storage section (31), the auxiliary storage section (31) being located outside the outer shell (18) of the housing (8), the first oil outlet (20c) being connected to the main circuit (24), and the second oil outlet (20d) being connected to the auxiliary storage section (31).

11. The turbine engine according to the preceding claim, characterized in that, The auxiliary storage unit (31) is directly connected to the second oil outlet (20d) of the housing (8).

12. The turbine engine according to claim 10 or 11, characterized in that, The auxiliary storage unit (31) is housed in a channel partition chamber (1c), which is configured to divide the airflow (F) generated by the fan (2) into a main flow (F1) and a secondary flow (F2).

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