Module for a turbine engine comprising a lubrication chamber

Abstract

The invention relates to a module comprising: - a lubrication chamber (16); - a first seal (30) and a second seal (31); - a pressurisation chamber (32); - an annular shroud (41) which axially faces either of the first and second seals (30, 31) and defines an annular portion (39, 40) of the pressurisation chamber (32), characterised in that the module further comprises an oil drainage port (44) formed in the stator (33) of the pressurisation chamber (32), and in that the shroud (41) is connected to the stator (33) so that the annular portion (39, 40) of the pressurisation chamber (32) forms an oil drainage cavity (H) liable to exit from the annular lubrication space (29) in order to be discharged outside the pressurisation chamber (38) through the oil drainage port (44).

Description

[0001] DESCRIPTION

[0002] TITLE: MODULE FOR A TURBOMACHINE COMPRISING A LUBRICATION ENCLOSURE

[0003] Technical field of the invention

[0004] The invention relates to the field of modules for aircraft turbomachines comprising at least one annular lubrication enclosure.

[0005] The invention relates in particular to the field of modules comprising a lubrication enclosure delimited axially by seals and an enclosure for pressurizing these seals.

[0006] Technical background

[0007] A turbomachine, particularly an aircraft turbomachine, generally extends along and around a longitudinal axis. In the case of a twin-spool, twin-flow turbomachine, it comprises a gas generator which typically comprises, from upstream to downstream, in the direction of gas flow in the turbomachine, a low-pressure compressor, a high-pressure compressor, a gas combustion chamber, a high-pressure turbine and a low-pressure turbine.

[0008] The low-pressure compressor rotor is typically connected to the low-pressure turbine rotor via a low-pressure shaft. The high-pressure compressor rotor is connected to the high-pressure turbine rotor via a high-pressure shaft.

[0009] The turbomachine further comprises a fan which is located upstream of the gas generator and which is rotated about the longitudinal axis by a fan shaft. In certain types of turbomachines with a high bypass ratio, the fan shaft may be connected to the low-pressure shaft via a speed reducer. The high- and low-pressure shafts are guided in rotation by means of guide bearings which must be lubricated to ensure their proper operation. In order to preserve the associated components of the turbomachine from this lubricating oil, the bearings are typically arranged in lubrication enclosures.

[0010] Each lubrication chamber is connected to a lubrication circuit that supplies oil to the lubrication chamber. Each chamber therefore contains a mixture of air and lubricating oil that must be contained to prevent oil leaks to the outside of the chambers and limit the risk of fire or the generation of an imbalance, for example.

[0011] Each lubrication enclosure is generally delimited by at least one rotating movable wall and by at least one rotating fixed wall located around this movable wall. In operation, it is therefore necessary to ensure a seal at each interface between a fixed wall and a movable wall. This seal is ensured by seals, typically of the dynamic type, which are mounted between the fixed wall and the movable wall, and which delimit the lubrication enclosures. Typically, first and second seals axially delimit the lubrication enclosure.

[0012] To limit oil leaks outside the enclosure through these seals, it is necessary to adjust the pressures between the inside and outside of the lubrication enclosures to ensure a continuous incoming air flow. To this end, it is proposed to bring pressurized air from outside the enclosure to the seals. For this, the air pressure outside the enclosure must be higher than the pressure inside the enclosure. The pressurized air located outside the enclosure will therefore naturally pass through the seals and enter the enclosure, which limits oil leaks from the enclosure to the outside through these seals.

[0013] For this purpose, the turbomachine may be equipped with a pressurization enclosure delimited by a stator which is located around the lubrication enclosure. The pressurization enclosure is supplied with pressurized air through an air inlet arranged for example in the movable wall of the lubrication enclosure. The pressurized air is for example taken from the upstream stages of the high-pressure compressor and directed to the seals of this enclosure through the air inlet of the pressurization enclosure.

[0014] In order to limit the risk of oil leakage through one of the seals, the pressures at the terminals of the lubrication enclosure, i.e. the pressure measured upstream of the first and second seals in the direction of circulation of the pressurized air, must be substantially identical, in other words in equilibrium, in order to guarantee the passage of the pressurized air in a substantially identical manner through each of the first and second seals. When there is a pressure differential upstream of the seals, then a preferential path of the pressurized air could be created for one of the seals. Such a preferential path would directly impact the sealing of the pressurized seal and could lead to significant oil leaks through this seal.

[0015] In some cases, the first seal is subjected to a higher pressure than the second seal due to the pressure gradient in the pressurization enclosure. Such a phenomenon is notably caused by the rotation of the pressurized air flow as it passes through the air inlet which is arranged on the movable wall. The pressurized air flow creates a vortex generating a pressure gradient. A first pressurized air flow exists at the first seal and a second air flow having a lower pressure exists at the second seal.

[0016] In order to maintain a sufficient pressure differential between the inside and outside of the lubrication enclosures, turbomachines can be equipped, for example, with an oil separator or a lubrication oil recovery pump. However, the greater the air flow at the first seal, for example, the greater the sizing of the recovery pump or oil separator, which directly impacts the mass and size of the turbomachine.

[0017] In order to minimize the pressure differential between the first and second seals, document FR-A1 -3 016 661 proposes equipping the lubrication chamber with an annular shell connected to the fixed wall of the lubrication chamber by a spacer. According to this document, the annular shell faces axially the first seal and delimits with the movable wall an annular passage for the pressurizing air coming from the air inlet and intended to supply the pressurization chamber. This shell makes it possible to limit the rotation of the air flow in the lower part of the pressurization chamber. The pressure gradient of the air flow is limited in the pressurization chamber, which makes it possible to increase the pressure at the second seal. Thanks to the shell of this document, the pressure differential between the first and second seals is minimized.

[0018] However, in document FR-A1-3 016 661, the spacer is equipped with orifices for the passage of pressurization air for the seals. If oil passes to the outside of the lubrication chamber via the seals, this oil could escape from the pressurization chamber through the orifices in the spacer, which does not allow optimal drainage of the oil from the pressurization chamber. This passage of oil through the orifices could create a risk of fire in the turbomachine.

[0019] Therefore, there is a need to provide a lubrication enclosure in which oil drainage is improved, to reduce the risk of fire in the turbomachine.

[0020] Summary of the invention

[0021] For this purpose, the invention proposes a module for an aircraft turbomachine, this module comprising:

[0022] - an annular lubrication enclosure comprising: - a wall movable around a longitudinal axis, the movable wall being annular and centered on the longitudinal axis,

[0023] - a fixed wall arranged coaxially around the movable wall,

[0024] - an annular lubrication space defined by the fixed and moving walls,

[0025] - a first annular sealing gasket located at a first axial end of the lubrication enclosure and between the movable and fixed walls,

[0026] - a second annular sealing gasket located at a second axial end of the lubrication enclosure, and between the movable and fixed walls,

[0027] - an annular pressurization enclosure which extends around the lubrication enclosure, the pressurization enclosure comprising:

[0028] - a stator arranged coaxially around the fixed wall,

[0029] - an annular pressurization space of the first and second seals defined by the stator and the fixed wall,

[0030] - a pressurized air inlet for supplying pressurized air to the pressurization enclosure, and

[0031] - an annular ferrule which faces axially one or other of the first and second seals and defining with the movable wall an annular passage for the pressurized air coming from the pressurized air inlet and intended to supply the pressurization enclosure, the ferrule axially delimiting with the fixed wall an annular part of the pressurization enclosure.

[0032] The module according to the invention is remarkable in that it further comprises an oil drainage orifice provided in the stator and in that the shell is connected to the stator so that the annular part of the pressurization enclosure forms an oil drainage cavity capable of exiting the annular lubrication space, the oil from the drainage cavity being channeled into the drainage cavity to be evacuated outside the pressurization enclosure through the oil drainage orifice.

[0033] The ferrule according to the invention therefore has a dual function of minimizing bypass pressure losses to reduce the pressure differential between the seals, and of draining oil in the event of an oil leak from the lubrication enclosure. The ferrule makes it possible, on the one hand, to limit or even eliminate the effects of the rotational drive of the pressurized air flow which enters through the pressurized air inlet into the pressurization enclosure. This makes it possible to minimize the pressure gradient of this pressurized air flow and therefore to increase the pressure of the pressurized air flow at one of the seals of the lubrication enclosure. The pressure difference between the first and second seals is thus reduced. The sealing of the lubrication enclosure is therefore improved, which makes it possible to reduce the risks of oil leakage at the first or second seal.

[0034] The shell according to the invention also makes it possible to create a cavity for recovering and draining any oil that has escaped from the lubrication enclosure. For simplicity, this recovery and drainage cavity is called a "drainage cavity" in the present invention. The oil is confined in this drainage cavity delimited in part by the shell of the invention, and this shell makes it possible to guide the oil that may have escaped into the drainage cavity towards a drainage orifice. The oil can thus be evacuated or collected by a drainage circuit connected to the drainage orifice, reducing the risk of fire in the turbomachine.

[0035] The invention may comprise one or more of the following features, taken in isolation from each other or in combination with each other:

[0036] -- the module includes a single drainage hole,

[0037] -- at least one bearing or gear is located in the lubrication space, -- the module comprises a pressurization circuit for the pressurization enclosure and a lubrication circuit for the lubrication enclosure,

[0038] -- the module includes an oil drainage circuit connected to the drainage port,

[0039] - the oil drainage hole opens into the pressurization enclosure and is located between 3 o'clock and 9 o'clock, preferably at 6 o'clock, by analogy with the dial of a clock, - the ferrule extends radially inwards from the stator and has an annular surface for guiding the oil towards the oil drainage hole,

[0040] - the ferrule is connected to the stator in a watertight manner,

[0041] - the ferrule has a shape that is at least partly truncated cone-shaped and flares out towards the longitudinal axis,

[0042] - the ferrule is attached and fixed to the stator,

[0043] - the stator comprises a ring having an axial end carrying the ferrule,

[0044] - the fixed wall comprises a first seal support extending radially towards the longitudinal axis from the fixed wall and cooperating with the movable wall to form the first seal,

[0045] - the ring is located outside the first seal support, in particular around the first seal support,

[0046] - the fixed wall comprises a second seal support extending radially towards the longitudinal axis from the stator and cooperating with the movable wall to form the second seal, and the stator comprises an annular axial end located downstream of the second seal support, the second seal support axially delimiting with the axial end a second annular part of the pressurization enclosure, the second seal support having a bore for the passage of pressurized air from the annular part of the pressurization enclosure to the second annular part,

[0047] - the air inlet comprises at least one orifice formed in the movable wall.

[0048] The invention also relates to a turbomachine for an aircraft which is remarkable in that it comprises at least one module according to any one of the preceding characteristics.

[0049] Brief description of the figures Other characteristics and advantages will emerge from the following description of non-limiting embodiments of the invention with reference to the appended drawings in which:

[0050] [Fig.1] Figure 1 is a longitudinal sectional view of an example of an aircraft turbomachine according to the invention;

[0051] [Fig.2] Figure 2 is a schematic view in longitudinal section of a lubrication enclosure and a pressurization enclosure according to the invention equipping the turbomachine of Figure 1.

[0052] Detailed description of the invention

[0053] An example of a turbomachine 1, in particular an aircraft turbomachine, according to the invention is shown in Figure 1. The turbomachine 1 is for example a bypass turbojet. The turbomachine 1 may have any other architecture and be in the form of a turboprop, for example. The turbomachine 1 is modular. It comprises a plurality of modules assembled together. In the remainder of the description, the terms “turbomachine module” and “turbomachine” are used interchangeably.

[0054] The turbomachine 1 extends along a longitudinal axis X. A gas flow F flows into the turbomachine 1.

[0055] For the purposes of the present invention, the terms "upstream" and "downstream" are understood to refer to the direction of flow of the gas flow F in the turbomachine 1. The gas flow F flows in particular from left to right in Figures 1 and 2.

[0056] Furthermore, the terms "longitudinal", "longitudinally", "radial", "radially" are understood relative to the longitudinal axis X of the turbomachine 1. The terms "external", "internal" are understood relatively to the distance from the longitudinal axis X along a radial axis perpendicular to the longitudinal axis X.

[0057] The turbomachine 1 comprises, from upstream to downstream, a fan 2 and a gas generator. The gas generator comprises, from upstream to downstream, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber 5, a high-pressure turbine 6 and a low-pressure turbine 7.

[0058] Each compressor 3, 4 comprises a compressor rotor 3a, 4a and each turbine 6, 7 comprises a turbine rotor 6a, 7a. The compressor rotors 3a, 4a and turbine rotors 6a, 7a are composed of a plurality of stages each comprising a bladed wheel.

[0059] The compressor rotor 3a of the low-pressure compressor 3 is connected to the turbine rotor 7a of the low-pressure turbine 7 by a low-pressure shaft 8. They form a low-pressure body.

[0060] The compressor rotor 4a of the high-pressure compressor 4 is connected to the turbine rotor 6a of the high-pressure turbine 6 by a high-pressure shaft 9. They form a high-pressure body.

[0061] The low pressure shaft 8 and high pressure shaft 9 are centered on the longitudinal axis X and rotatable about the longitudinal axis X. The high pressure shaft 9 is arranged coaxially around the low pressure shaft 8.

[0062] The gas flow F passes through the blower 2 and is divided into a primary air flow F1 passing through a primary vein v1 and a secondary air flow F2 passing through a secondary vein v2 surrounding the primary vein. The primary air flow F1 passes through the low pressure 3 and high pressure 4 compressors. The compressed primary air flow F1 then passes through the combustion chamber 5 in which it is mixed with a fuel. The gases resulting from the combustion thus pass through the high pressure 6 and low pressure 7 turbines. The energy of the gases is transformed by the turbine rotor 7a of the low pressure turbine 7 into mechanical energy making it possible to drive the low pressure shaft 8 in rotation and consequently the low pressure compressor 3.

[0063] The fan 2 comprises a mobile disc rotating around the longitudinal axis X and blades 2a carried by the disc and regularly distributed around the longitudinal axis X. In the example of figure 1, the fan 2 is surrounded by a fan casing 2b. The fan 2 is of the ducted type. The fan casing 2b carries a nacelle 2c and together define a fan compartment 2d.

[0064] According to another example not shown, the blower 2 is of the unducted type.

[0065] The fan disc 2 is rotated by a fan shaft

[0066] 10. In the example described, and therefore optionally, the fan shaft 10 is connected to the low pressure shaft 8 via a speed reducer 11. The speed reducer 11 is of the mechanical type. It is for example an epicyclic or planetary gear. In a manner not illustrated, the speed reducer 11 conventionally comprises a sun gear and a crown both centered on the longitudinal axis X. It further comprises satellites meshing with the sun gear and the crown. It further comprises a planet carrier.

[0067] The solar is rotationally fixed to the low pressure shaft 8 and forms the input of the speed reducer 11, while one or the other of the crown and the planet carrier, depending on the configuration of the reducer 11, is rotationally fixed to the fan shaft 10 and forms the output of the speed reducer.

[0068] 11.

[0069] The speed reducer 11 allows the fan shaft 10 to be driven at a rotational speed lower than the rotational speed of the low pressure shaft 8. This allows the bypass ratio of the turbomachine 1 to be increased.

[0070] The turbomachine 1 further comprises an inter-compressor casing 12 arranged axially between the low-pressure compressor 3 and the high-pressure compressor 4. The inter-compressor casing 12 comprises, for example, an inner shell and an outer shell which are centered on the longitudinal axis X. The inner and outer shells are, for example, connected by arms.

[0071] The turbomachine 1 may further comprise an inlet casing 13. The inlet casing 13 is arranged axially between the fan 2 and the low-pressure compressor 3. The inlet casing 13 comprises, for example, an inner shell and an outer shell which are centered on the longitudinal axis X. The inner and outer shells are, for example, connected by arms.

[0072] The turbomachine 1 may further comprise an inter-turbine casing 14. The inter-turbine casing 14 is arranged axially between the high-pressure turbine 6 and the low-pressure turbine 7.

[0073] The turbomachine 1 may further comprise an inter-vein compartment v3 located between the primary vein v1 and the secondary vein v2.

[0074] The turbomachine 1 comprises at least one bearing 15. In particular, the fan shaft 10 is guided in rotation by a first bearing 15a and advantageously a second bearing 15b. The first and second bearings 15a, 15b are arranged radially between the fan shaft 10 and the inlet casing 13.

[0075] The low pressure shaft 8 is guided in rotation by at least a third and fourth bearing 15c, 15d. The third bearing 15c is arranged radially between the inlet casing 13 and the low pressure shaft 8. The fourth bearing 15d is arranged radially between the inter-compressor casing 12 and the low pressure shaft 8.

[0076] The high-pressure shaft 9 is guided in rotation by a fifth bearing 15e. The fifth bearing 15e is, for example, arranged radially between the high-pressure shaft 9 and the inter-turbine casing 14.

[0077] The low pressure shaft 8 can be guided in rotation downstream by a sixth bearing 15f arranged radially between a downstream end of the low pressure shaft 8 and the inter-turbine casing 14 for example.

[0078] Each bearing includes, for example, a rolling bearing. The rolling bearing is, for example, at least one row of balls or rollers.

[0079] The bearings 15 and the possible speed reducer 11 are lubricated with oil to ensure their proper operation. To avoid contaminating the related components of the turbomachine 1 with oil, the bearings 15 and the speed reducer 11 are arranged in lubrication chambers. The lubrication chambers may also be intended for the lubrication of other elements of the turbomachine 1, such as gears, bearings.

[0080] For this purpose, the turbomachine 1 further comprises at least one lubrication enclosure 16, in particular a first upstream enclosure 17 in which the first, second and third bearings 15a, 15b, 15c and the speed reducer 11 are arranged, a second upstream lubrication enclosure 18 in which the fourth bearing 15d is arranged and a downstream lubrication enclosure 19 in which the fifth and sixth bearings 15e, 15f are arranged.

[0081] Depending on the configuration of the turbomachine 1, the number of bearings 15 and lubrication chambers 16 may vary.

[0082] Each lubrication enclosure 16 is annular. Each lubrication enclosure 16 is delimited externally by a fixed wall 20 such as a casing and internally by a movable wall such as a shaft.

[0083] For example, the first upstream lubrication enclosure 17 is located in the inner shell of the inlet casing 13 and is delimited internally by the fan shaft 10. The second upstream lubrication enclosure 18 is located in the inner shell of the inter-compressor casing 12 and is delimited internally by the low pressure shaft 8 and the downstream lubrication enclosure 19 is located in the inner shell of the inter-turbine casing 14 and is delimited internally by the high pressure shaft 9.

[0084] With reference to Figure 2, the fixed wall 20 of the lubrication enclosure 16 is annular and centered on the longitudinal axis X. It is located coaxially around the movable wall 21 which is also annular and centered on the longitudinal axis X. The fixed wall 20 advantageously comprises an annular body 20a which extends axially and an annular bearing support 22 which extends radially inwards from the fixed wall 20 and in particular from the annular body 20a. The bearing support 22 delimits with the movable wall 21 an annular space in which the rolling bearing 15 is located. The fixed wall 20 further comprises first and second seal supports 23, 24 located on either side of the bearing support 22. The first and second seal supports 23, 24 are annular and extend radially from the fixed wall 20. The first seal support 23 is arranged upstream of the second seal support 24.The first and second seal supports 23, 24 each comprise an annular ferrule 23a, 24a extending radially inward from the cylindrical body 20a and an annular sole 23b, 24b carried by the annular ferrule 23a, 24a. The annular ferrule 24a of the second seal support 24 advantageously comprises at least one bore 24c. The movable wall 21 may comprise an axially extending cylindrical body 25 and first and second annular journals 26, 27 extending radially and outwardly from the cylindrical body 25. The movable wall 21 may comprise a third journal 28 arranged upstream of the first and second journals 26, 27 and extending radially outwardly from the cylindrical body 25. Each journal 26, 27, 28 comprises a radial annular end 26a, 27a, 28a connected to the cylindrical body 25 and an axial annular end 26b, 27b, 28b extending axially.

[0085] The fixed and movable walls 20, 21 delimit between them an annular lubrication enclosure space 29 in which one or more bearings 15 and / or the possible speed reducer 11 may be located. For simplification, this space is also called lubrication space 29 in the present description.

[0086] The lubrication space 29 is supplied with oil by at least one lubrication circuit C1. The lubrication circuit C1 comprises an oil outlet opening into the lubrication space 29 and an oil inlet connected for example to an oil reservoir for supplying oil to the lubrication circuit C1. The lubrication oil from the oil reservoir is thus projected into the lubrication enclosure 16 through the oil outlet for lubricating the bearings and / or meshes, for example of the bearing(s) 15 and the speed reducer 11.

[0087] In order to limit oil leaks outside the lubrication enclosure 16, a first seal 30 is arranged at a first axial end of the lubrication enclosure 16 and a second seal 31 is arranged at a second axial end of the lubrication enclosure 16. The first and second seals 30, 31 are each located radially between the fixed wall 20 and the movable wall 21. The first seal 30 is located upstream of the second seal 31. The seal 30 can be called the upstream seal and the second seal 31 can be called the downstream seal.

[0088] The first and second seals 30, 31 are advantageously of the dynamic type. A dynamic type seal is understood as an assembly limiting leaks of a fluid between the fixed wall 20 and the movable wall 21. Preferably, the first and second seals 30, 31 are labyrinth seals. For example, the first seal 30 is located between the first seal support 23 and the movable wall 21. In particular, the first seal 30 comprises wipers carried by the sole 23b of the first seal support 23 and which cooperate with an abradable coating carried by the first journal 26. The second seal 31 is for example located between the second seal support 24 and the movable wall 21. In particular, the second seal 31 comprises wipers carried by the sole 24b of the second seal support 24 and which cooperate with an abradable coating carried by the second journal 27.

[0089] In order to limit oil leaks through the first and second seals 30, 31, the turbomachine 1 further comprises an annular pressurization enclosure 32 located coaxially around the lubrication enclosure 16. The pressurization enclosure 32 comprises a stator 33 located coaxially around the fixed wall 20 of the lubrication enclosure 16. The stator 33 is annular and centered on the longitudinal axis X. It comprises an annular body 34 extending axially between first and second axial ends 35, 36. Each first and second axial ends 35, 36 are annular and extend radially inward from the annular body 34. The first axial end 35 is located upstream of the second axial end 36. The stator 33 further comprises a ring 37 connected to the annular body 34 and located axially between the axial ends 35, 36. The ring 37 extends radially inward from the annular body 34.The ring 37 has a radial end 37a secured to the annular body 34 and extending radially inwards and an axial end 37b extending axially from the radial end 37a. The axial end 37b extends for example axially upstream from the radial end 37a. The ring 37 is advantageously located axially between the first axial end 35 of the stator 33 and the first seal support 23 of the lubrication enclosure 16.

[0090] Furthermore, the stator 33 can be connected to the fixed wall 20 of the lubrication enclosure 16. The stator 33 can be connected to the fixed wall 20 by the second seal support 24. The bore 24c of the second seal support 24 is located radially between the stator 33 and the annular body 20a of the fixed wall 20.

[0091] The pressurization enclosure 32 comprises an annular pressurization space 38 delimited by the stator 33 and the fixed wall 20 of the lubrication enclosure 16. The pressurization space 38 typically comprises a first annular portion 39 for pressurizing the first seal 30 and a second annular portion 40 for pressurizing the second seal 32. Advantageously, the first annular portion 39 communicates fluidically with the second annular portion 40 via the bore 24c. The first annular portion 39 is for example connected to the second annular portion 40 by an annular central portion 38' delimited radially by the annular body 34 of the stator 33 and the annular body 20a of the fixed wall 20.

[0092] According to the invention, the turbomachine 1 further comprises an annular shroud 41 connected to the stator 33. The shroud 41 is preferably carried by the ring 37 of the stator 33, in particular by the axial end 37b of this ring 37. Preferably, the shroud 41 is attached and fixed to the stator 33. The shroud 41 is fixed to the stator 33 in a sealed manner. Thus, there is no passage or fluid path between the stator 33 and the shroud 41. According to another example, the shroud 41 and the stator 33 form a single-piece assembly or are made in one piece. The shroud 41 extends radially towards the inside of the turbomachine 1. The shroud 41 has an at least partly frustoconical shape. The shell 41 is flared, preferably towards the inside of the turbomachine 1, that is to say in the direction of the longitudinal axis X.

[0093] The ferrule 41 comprises a first annular surface 41a and a second annular surface 41b facing one or other of the seals 30, 31. The ferrule 41 further comprises an annular peripheral edge 41c.

[0094] The ferrule 41 axially faces one of the first and second seals 30, 31. Preferably, the ferrule 41 faces the first seal 30 which is located upstream of the second seal 31. The ferrule 41 is thus located upstream of the first seal 31. Thus, the second annular surface 41b is opposite the first seal 31.

[0095] The ferrule 41 is located around or outside the movable wall 21 of the lubrication enclosure 16. In particular, the ferrule 41 is located around or outside the first journal 26. In particular, the peripheral edge 41c is opposite the movable wall 21.

[0096] The ferrule 41 axially delimits with the fixed wall 33 the first annular part 39 of the pressurization enclosure 32. In particular, this first annular part 39 is axially delimited by the first seal support 23 and the ferrule 41.

[0097] In order to supply the pressurization enclosure 32 with pressurized air, the turbomachine 1 comprises a pressurized air inlet 42 and a pressurized air passage 43 opening into the pressurization enclosure 32.

[0098] The pressurized air inlet 42 is fluidically connected to a pressurization circuit C2. The pressurization circuit C2 comprises an air sampling member (not shown) configured to sample air from the high-pressure compressor 4, for example.

[0099] The pressurized air inlet 42 comprises at least one orifice which is advantageously arranged in the movable wall 25 of the lubrication enclosure 16. In particular, the pressurized air inlet 42 is located axially between the first journal 26 and the third journal 28. The orifice of the pressurized air inlet 42 is open, that is to say that it passes through the movable wall 25 on either side. The pressurized air inlet 42 could comprise a plurality of orifices.

[0100] The pressurized air passage 43 is delimited radially by the ferrule 41 and the movable wall 21 of the lubrication enclosure 16. The pressurized air passage 43 is in particular defined radially between the peripheral edge 41c of the ferrule 41 and the movable wall 21, in particular the first journal 26.

[0101] According to the invention, the pressurized air A1 is taken from the high-pressure compressor 4 for example, then conveyed through the pressurization circuit C2 to the pressurized air inlet 42. The pressurized air A1 passes through the pressurized air inlet 42 then the pressurized air passage 43 and supplies the first annular part 39 of the pressurization enclosure 32.

[0102] The pressurized air A1 is divided into a first pressurized air flow P1 which pressurizes the first seal 30 and into a second pressurized air flow P2 which enters the second annular part 40 of the pressurization enclosure 32 through the bore 24c for example. This second pressurized air flow P2 makes it possible to pressurize the second seal 31.

[0103] Thanks to the ferrule 41, the pressure gradient of the pressurized air flow A1 in the vicinity of the first seal 30 is limited or even eliminated, which makes it possible to reduce the pressure differential upstream of the first and second seals 30, 31, the term upstream referring to the circulation of the pressurized air flow A1. The pressure of the first pressurized air flow P1 and of the second pressurized air flow P2 is substantially equal, apart from the linear pressure losses. The sealing of the seals 30, 31 is thus improved, which makes it possible to limit oil leaks outside the lubrication space 29.

[0104] However, lubricating oil can still escape from this lubrication space 29. For this purpose, in order to contain and evacuate this oil, the turbomachine 1 comprises a drainage cavity 39 and an oil drainage orifice 44 connected to an oil drainage circuit C3. The oil drainage orifice 44 makes it possible to evacuate the oil H leaving the lubrication space 29 outside the pressurization enclosure 32. The oil drainage orifice 44 is provided in the stator 33 of the pressurization enclosure 32. In particular, the oil drainage orifice 44 is provided in the annular body 34 of the stator 33. The oil drainage orifice 44 is in particular located axially between the ring 37 and the second seal support 24.

[0105] The oil drainage hole 44 is a through hole. It passes through the stator 33 on either side. The oil drainage hole 44 opens into the pressurization enclosure 32, in particular into the central part 38' of this pressurization enclosure 32.

[0106] The oil drainage orifice 44 is for example located between 3 o'clock (three o'clock) and 9 o'clock (nine o'clock), preferably at 6 o'clock (six o'clock) by analogy with the corresponding position of the hands on a clock face. Such a position makes it possible to promote the flow of the oil H by gravity and its evacuation through the oil drainage orifice 44.

[0107] Preferably, the oil drain port 44 is unique.

[0108] According to the invention, the drainage cavity 39 is formed by the first annular part 39 of the pressurization enclosure 32. Such a drainage cavity 39 makes it possible to collect the oil H for its evacuation through the oil drainage orifice 44. The ferrule 41 makes it possible to confine the oil in the drainage cavity 39 and to guide this oil H towards the drainage evacuation orifice 44. In particular, the second annular surface 41 b is a surface for guiding this oil H towards the oil drainage orifice 44.

[0109] Thanks to the configuration of the shell 41 according to the invention, and in particular in that the shell 41 is carried by the stator 33, the oil H which escapes outside the lubrication space 29 through the first seal 30 is confined in the drainage cavity 39 formed by the first annular part 39 of the pressurization enclosure 32. This oil H is further guided by the shell 41 towards the oil drainage orifice 44. Thanks to the shell 41 of the invention, the circulation of the oil H which escapes from the lubrication enclosure 16 is controlled, which limits the risk of fire in the turbomachine 1.

[0110] Furthermore, the pressurized air passage 43 is dimensioned so that the flow rate of the pressurized air flow A1 prevents the oil H from escaping through this pressurized air passage 43. The dimension of this pressurized air passage 43 can be adjusted by modifying the dimensions of the ferrule 41 in particular. This makes it possible to limit oil leaks outside the drainage cavity 39.

[0111] Furthermore, the turbomachine 1 may comprise an additional seal 45 located upstream of the first seal 30. The additional seal 45 is advantageously located radially between the movable wall 21 and the stator 33. In particular, the additional seal 45 is located radially between the third journal 28 and the stator 33.

[0112] The additional seal 45 advantageously makes it possible to maintain the pressure of the pressurized air flow A1 of the pressurization circuit C2 after its passage through the pressurized air inlet 42 and to maintain the pressure of this pressurized air flow A1 in the drainage cavity 39.

Claims

CLAIMS 1. Module for an aircraft turbomachine (1), this module comprising: - an annular lubrication enclosure (16) comprising: - a movable wall (21) around a longitudinal axis (X), the movable wall being annular and centered on the longitudinal axis (X), - a fixed wall (20) arranged coaxially around the movable wall (21), - an annular lubrication space (29) defined by the fixed and movable walls (20, 21), - a first annular sealing joint (30) located at a first axial end of the lubrication enclosure (16) and between the movable and fixed walls (21, 20), - a second annular sealing joint (31) located at a second axial end of the lubrication enclosure (16), and between the movable and fixed walls (21, 20), - an annular pressurization enclosure (32) which extends around the lubrication enclosure (16), the pressurization enclosure (32) comprising: - a stator (33) arranged coaxially around the fixed wall (20), - an annular pressurization space (38) of the first and second seals (30, 31), defined by the stator (33) and the fixed wall (20), - a pressurized air inlet (42) for supplying pressurized air to the pressurization enclosure (32), and - an annular ferrule (41) which faces axially one or the other of the first and second seals (30, 31) and defining with the movable wall (21) an annular passage for the pressurized air (43) coming from the pressurized air inlet (42) and intended to supply the pressurization enclosure (32), the ferrule (41) axially delimiting with the fixed wall (20) an annular part (39, 40) of the pressurization enclosure (32), characterized in that the module further comprises an oil drainage orifice (44) formed in the stator (33) and in that the ferrule (41) is connected to the stator (33) so that the annular portion (39, 40) of the pressurization enclosure (32) forms an oil drainage cavity (H) capable of exiting the annular lubrication space (29), the oil (H) from the drainage cavity being channeled into the drainage cavity to be discharged outside the pressurization enclosure (38) through the oil drainage orifice (44).

2. Module according to the preceding claim, characterized in that the oil drainage orifice (44) opens into the pressurization enclosure (38) and is located between 3 o'clock and 9 o'clock, preferably at 6 o'clock, by analogy with the dial of a clock.

3. Module according to the preceding claim, characterized in that the ferrule (41) extends radially inwards from the stator (33) and has an annular surface (41 b) for guiding the oil (H) towards the oil drainage orifice (44).

4. Module according to any one of the preceding claims, characterized in that the ferrule (41) is connected to the stator (33) in a sealed manner.

5. Module according to any one of the preceding claims, characterized in that the ferrule (41) has an at least partly frustoconical shape which flares in the direction of the longitudinal axis (X).

6. Module according to any one of the preceding claims, characterized in that the ferrule (41) is attached and fixed to the stator (33).

7. Module according to any one of the preceding claims, characterized in that the stator (33) comprises a ring (37) having an axial end (37b) carrying the ferrule (41).

8. Module according to any one of the preceding claims, characterized in that the fixed wall (20) comprises a first joint support (23) extending radially towards the longitudinal axis (X) from the fixed wall (20) and cooperating with the movable wall (21) to form the first seal (30).

9. Module according to claims 7 and 8, characterized in that the ring (37) is located outside the first seal support (23), in particular around the first seal support (23).

10. Module according to any one of the preceding claims, characterized in that the fixed wall (20) comprises a second joint support. (24) extending radially towards the longitudinal axis (X) from the stator (33) and cooperating with the movable wall (21) to form the second seal (31), and in that the stator (33) comprises an annular axial end (36) located downstream of the second seal support (24), the second seal support (24) axially delimiting with the axial end (36) a second annular part (39, 40) of the pressurization enclosure (38), the second seal support (24) having a bore (24c) for the passage of pressurized air (A1) from the annular part (39, 40) of the pressurization enclosure (32) to the second annular part (40).

11. Module according to any one of the preceding claims, characterized in that the air inlet (42) comprises at least one orifice formed in the movable wall (25).

12. Turbomachine (1) for an aircraft, characterized in that it comprises at least one module according to any one of the preceding claims.

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