Assembly for turbomachine accessory housing

Abstract

This disclosure relates to an accessory housing assembly (1) for a turbomachine, assembly (1) comprising: - a tubular shaft (2) having a first channel (21), - a pinion (3) rotationally coupled to the tubular shaft (2), and - at least one annular air / oil mixture separator (4a, 4b) arranged around the tubular shaft (2) and rotationally fixed to the tubular shaft (2), wherein assembly (1) includes a filtered airflow segregation device (5), the segregation device (5) being mounted radially inside the tubular shaft (2) and being rotationally fixed to the tubular shaft (2), the segregation device (5) comprising at least one second channel (51) extending axially and being arranged radially outside the first channel (21), said at least one second channel (51) being in upstream fluidic communication with a filtered air outlet (45b) of one of said at least one annular organ (4a,4b).Figure from the summary: Figure 3.

Description

Title of the invention: Assembly for a turbine accessory housing technical field

[0001] This disclosure relates to an accessory housing assembly for a turbomachine, and more particularly to an assembly capable of ensuring the separation of an air / oil mixture. Previous technique

[0002] An accessory gearbox is a component used to support and mechanically drive other equipment, called accessories, such as electric generators, oil or fuel pumps, or other components necessary for the operation of the turbomachine or the aircraft on which the turbomachine is mounted. To provide this drive, the required power is taken from a main shaft of the turbomachine, generally by means of a radial drive shaft meshed with the main shaft, and this power is then mechanically transmitted to the accessory gearbox. The accessory gearbox typically comprises a fixed housing containing gears that distribute power to the various accessories.

[0003] The accessory gearbox can also be combined with an air / oil mixture separation device, also known as an oil separator. To do this, air is drawn directly from the turbomachine's air stream. This air then passes through the turbomachine and is subsequently vented to the outside of the turbomachine to limit the pressure buildup in other areas of the turbomachine. This air, having passed through various areas of the turbomachine, is laden with oil used for cooling and lubricating the bearings and gears of the rotating assemblies. To avoid the release of oil-laden air, mitigate the environmental impact of turbomachines, reduce oil consumption, and limit the need for oil reservoir refilling, it is important to provide devices that separate the oil from the air before venting the air to the outside of the turbomachine.

[0004] It is known to implement the air / oil mixture separation device in an additional accessory outside the accessory housing. [Fig. 1] represents such a device comprising an air / oil mixture inlet 11, a housing 12 delimiting a first chamber 13 for receiving the air / oil mixture and a second chamber 14 for receiving the oil extracted from the air / oil mixture, a filter element 15, an oil outlet 16 and a shaft 17 having a channel 18 for discharging the filtered air, the filter element 15 being integral with the shaft 17.

[0005] The air and oil mixture is brought into the crankcase through inlet 11, then passes through The filter element 15 separates the oil from the air and extracts it radially outwards by centrifugal force, before it enters the second chamber 14 where it is discharged at the bottom through outlet 16. The filtered air, having passed through the filter element 15, is directed towards the channel 18 of the shaft 17 before being discharged to the outside. The separation of the mixture by the filter element 15 can, in particular, be achieved by rotating cross-linked foams or a porous material.

[0006] This arrangement, although allowing for the treatment of a large air / oil mixture flow rate, is bulky.

[0007] However, some recent engines require the accessory drive unit to be installed in a more confined space within the turbomachine. In this case, the compactness of the accessory drive unit is more important.

[0008] With the aim of improving the compactness of air / oil mixture separation devices, one solution provided is to integrate the separation device within the accessory housing, as is known from document FR 3 064 305 in the name of the Applicant.

[0009] Figure 2 illustrates such a device arranged and driven by a mechanical power take-off at the accessory gearbox. The device comprises an annular air / oil mixture inlet 11, a filter element 15, an oil outlet 16, a rotating shaft 17 with axis of rotation X, and a toothed pinion 19 mounted on the shaft. The toothed pinion meshes with another pinion in the accessory gearbox to drive the shaft 17 in rotation. The tubular shaft 17 internally forms a channel 18 for the discharge of filtered air. The terms axial and radial are defined with respect to the axis of rotation X.

[0010] The air-oil mixture is drawn into the crankcase through inlet 11, then passes through filter element 15 where the oil is separated from the air and extracted radially outwards by centrifugal force, before being discharged. The filtered air, having passed through filter element 15, is directed to channel 18 of shaft 17 before being discharged. The separation of the mixture by filter element 15 can similarly be achieved by rotating cross-linked foams or a porous material.

[0011] However, such integration of the separation device into the accessory housing implies a reduction in the diameter of the filter elements to be compatible with the external diameter of a toothed pinion. This results in higher pressure losses than in the external filtration configuration.

[0012] There is currently a need to recover as much energy as possible in order to improve the efficiency of the turbomachine.

[0013] The invention aims to provide a solution to this need in a simple, inexpensive and reliable way. Summary

[0014] This disclosure improves the situation.

[0015] An accessory housing assembly for a turbomachine is proposed. The assembly comprises a tubular shaft designed to rotate about an axis of rotation, a pinion rotationally coupled to the tubular shaft, and at least one annular air / oil mixture separator arranged around the tubular shaft and rotationally fixed to it. The tubular shaft has a first internal tubular channel coaxial with the shaft. This at least one annular element comprises an annular body housing an annular filter. Each annular body includes an air / oil mixture inlet, an oil outlet opening radially outside the annular body, and a filtered air outlet opening radially inside the annular body. The assembly includes a device for segregating the filtered airflows, specifically for segregating the filtered airflows originating from the first and second annular elements, respectively.The segregation device is mounted radially inside the tubular shaft and is rotationally fixed to the tubular shaft. The segregation device comprises at least one second channel extending axially and arranged radially outside the first channel. This at least one second channel is in upstream fluidic communication with the filtered air outlet of one of said at least one annular component. In particular, the filtered air outlet of the second annular component opens radially into said at least one second channel.

[0016] The terms axial and radial are defined with respect to the axis of rotation of the rotating tubular shaft.

[0017] The implementation of the filtered airflow segregation device further improves the performance of the air / oil mixture filtration by the annular components.

[0018] The assembly preferably comprises a first annular element and a second annular element for separating the air / oil mixture.

[0019] In particular, two annular organs are understood to mean that the annular filters of each of the two annular organs are fluidly separated from each other.

[0020] Advantageously, the first annular element is arranged upstream of the second annular element in a direction of filtered air flow in the first channel. The filtered air outlet of the first annular element opens radially into the first channel. Said at least one second channel is in fluidic communication upstream with the filtered air outlet of the second annular element and downstream with the first channel.

[0021] In particular, the air filtered by the first annular organ flows only in the first channel and only the air filtered by the second annular organ flows in the second channel before joining the first channel further downstream.

[0022] More specifically, each of the annular air / oil mixture separation elements is configured so that an air / oil mixture opens into each element The annular element is entered through the corresponding air / oil mixture inlet and then rotated within the annular element such that the oil contained in the air / oil mixture is radially centrifuged out of the annular element through the corresponding oil outlet, and the filtered air exits radially inward through the filtered air outlet. The filtered air from the first annular element exits radially directly into the first channel. The filtered air from the second annular element exits radially into at least one second channel before exiting axially further downstream into the first channel.

[0023] By implementing two separate annular air / oil mixture separation devices, the present disclosure provides at least two different paths for filtering the air / oil mixture. This configuration thus increases the air passage area and consequently reduces the pressure losses of the assembly, and more generally of the turbomachine. Furthermore, the present disclosure increases the compactness of the means implemented for separating an air / oil mixture thanks to the compact integration of said at least two annular air / oil mixture separation devices into the accessory housing.

[0024] Furthermore, the implementation of the filtered airflow segregation device further improves the performance of the air / oil mixture filtration by the two annular elements. Indeed, performing fluidic separation of the filtered air exiting each annular element limits the impact of the air / oil mixture being drawn in through the second annular element on the air / oil mixture being drawn in through the first annular element. Consequently, such a configuration reduces the overall pressure drop, and therefore the pressure drop across the accessory housing.

[0025] Furthermore, the assembly may include means for air circulation so that air circulation exists between the air / oil mixture inlet of the annular body and the inside of the tubular shaft in operation.

[0026] In particular, the second channel opens axially downstream, specifically from the second annular element, into the first channel. This configuration advantageously prevents the flow of filtered air in the second channel from excessively disturbing the flow of filtered air in the first channel when these flows meet.

[0027] The filtered air outlet of the first annular organ and the second annular organ may include a plurality of filtered air outlet orifices.

[0028] Advantageously, the segregation device is formed as a single unit with the tubular shaft.

[0029] Alternatively, the segregation device may be a separate part of the tubular shaft intended to be mounted radially inside the tubular shaft. This ca This characteristic makes it advantageous to facilitate the implementation and maintenance of the segregation device.

[0030] Advantageously, the segregation device comprises a radially internal annular ring and a radially external annular ring coaxial with each other, delimiting the second channel. In particular, the radially internal annular ring forms a wall radially delimiting the first and second channels.

[0031] The segregation device includes, in particular, a circumferential bottom wall connecting the radially external annular ferrule to the radially internal annular ferrule. The circumferential bottom wall is arranged, in particular, at an upstream axial end of the second channel. This wall occludes the second channel at its upstream axial end.

[0032] The radially external annular ferrule can in particular be mounted against a wall of the first channel.

[0033] The radially external annular ferrule advantageously comprises at least one first opening radially opposite the filtered air outlet of the second annular element. The filtered air exiting the filtered air outlet of the second annular element can thus pass radially through said at least one first opening in order to exit radially into the second channel.

[0034] The radially external annular ferrule may, in particular, comprise a plurality of first openings. The number of first openings is preferably equal to the number of filtered air outlets of the second annular element.

[0035] Advantageously, the segregation device comprises a plurality of second channels distributed circumferentially, preferably regularly, around the axis of rotation. The number of second channels is preferably equal to the number of filtered air outlets of the second annular component. For example, the segregation device may comprise between 6 and 10 second channels.

[0036] The segregation device may, in particular, include first radial walls extending axially and radially between the inner radially oriented annular ferrule and the outer radially oriented annular ferrule, and circumferentially delimiting the second channels from one another. The implementation of the first radial walls makes it possible, in particular, on the one hand, to improve the mechanical strength of the segregation device, and on the other hand, to guide the flow axially in the second channels.

[0037] Advantageously, the radially external annular ferrule extends axially upstream beyond the filtered air outlet of the first annular element. The radially external annular ferrule includes at least one second opening radially opposite the filtered air outlet of the first annular element. The filtered air exiting the filtered air outlet of the first annular element can thus pass radially through said at least one second opening in order to exit radially into the first channel. This configuration of the radially external annular ferrule improves the retention of the segregation device in the tubular shaft.

[0038] The radially external annular ferrule may, in particular, include a plurality of secondary openings. The number of secondary openings is preferably equal to the number of filtered air outlets of the first annular element.

[0039] The segregation device may include radial guide fins extending axially and radially inwards from the radially external annular ferrule, at the periphery of the second openings. The implementation of the radial guide fins makes it possible, in particular, on the one hand, to improve the mechanical strength of the segregation device, and on the other hand, to radially guide the flow of filtered air towards the first channel.

[0040] The radial guide fins can in particular be connected to the circumferential bottom wall of the segregation device.

[0041] Each of the radial guide fins may include a radially internal end opposite the radially external annular ferrule. The radially internal end of the radial guide fins is free. Advantageously, the radially internal end of the radial guide fins is arranged in substantially the same radial position as the radially internal annular ferrule. This arrangement allows the filtered air exiting the first annular element to be guided radially, initially, to the level of the radially internal annular ferrule, and then axially towards the interior of the radially internal annular ferrule.

[0042] Advantageously, the pinion is arranged axially between the first annular element and the second annular element. This configuration allows for a balanced mounting of the annular elements on the tubular shaft on either side of the pinion.

[0043] The annular filter may comprise a plurality of filter elements and the annular body may form a plurality of circumferentially side-by-side housings separated by radial walls of the annular body, each housing of the plurality of housings housing a filter element of the plurality of filter elements.

[0044] The annular filter can in particular be made of a cross-linked foam or of a porous material.

[0045] According to another aspect, an accessory housing for a turbomachine is proposed, comprising an assembly as previously described. The assembly as previously described is notably mounted inside the accessory housing.

[0046] Advantageously, the accessory housing comprises a casing containing a plurality of power take-offs capable of being driven by a shaft of the turbomachine and capable of rotating at least one accessory piece of equipment. Each power take-off includes, in particular, a shaft and at least one pinion rotationally coupled to the shaft. The assembly is arranged, in particular, at one of the power take-offs of the accessory case.

[0047] The accessory box may comprise a plurality of assemblies as previously described, each of the assemblies being mounted to a separate power outlet of the accessory box.

[0048] According to another aspect, a turbomachine is proposed comprising the accessory housing as previously described. Brief description of the drawings

[0049] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0050] [Fig.1] schematically illustrates a cross-sectional view of an example of a separation device according to the prior art. Fig. 2

[0051] [Fig.2] schematically illustrates a cross-sectional view of another example of a separation device according to the prior art. Fig. 3

[0052] [Fig.3] schematically illustrates a cross-sectional view of an assembly according to one embodiment. Fig. 4

[0053] [Fig.4] schematically illustrates two views (figures 4A and 4B) of an assembly according to one embodiment. Fig. 5

[0054] [Fig.5] schematically illustrates a view of a segregation device according to one embodiment. Description of the implementation methods

[0055] Figures 3, 4 and 5 represent, at least partially, an assembly 1 for an accessory housing of a turbomachine. The assembly is mounted inside the accessory housing.

[0056] The accessory gearbox conventionally comprises a housing containing a plurality of power take-offs capable of being driven by a shaft of the turbomachine and capable of rotating at least one accessory component. Each power take-off includes, in particular, a shaft and at least one pinion rotationally coupled to the shaft. The assembly according to this disclosure is mounted, in particular, to one of the power take-offs of the accessory gearbox. The accessory gearbox may comprise a plurality of assemblies, each of the assemblies being mounted to a separate power take-off of the accessory gearbox.

[0057] Assembly 1 comprises a tubular shaft 2 intended to be driven in rotation around of a rotation axis X and a pinion 3 coupled in rotation to the tubular shaft 2. The tubular shaft has a first internal tubular channel 21 coaxial with the tubular shaft 2.

[0058] The terms axial and radial are defined with respect to the axis of rotation X of the rotating tubular shaft.

[0059] More particularly, the pinion 3 comprises an annular disc 31 carrying at its radially external end a toothing intended to be coupled in rotation with a corresponding toothing of another pinion.

[0060] Assembly 1 comprises at least one, preferably a first 4a and a second 4b, annular air / oil mixture separation elements arranged around the tubular shaft 2 and rotationally fixed to the tubular shaft 2. The annular air / oil mixture separation element is also referred to as an oil separator. The first annular element 4a is arranged, in particular, upstream of the second annular element 4b in a direction of filtered air flow in the first channel 21.

[0061] By implementing two separate annular air / oil mixture separation devices, the present disclosure provides at least two different paths for filtering the air / oil mixture. This configuration thus increases the air passage area and consequently reduces the pressure losses of the assembly, and more generally of the turbomachine. Furthermore, the present disclosure increases the compactness of the means implemented for separating an air / oil mixture thanks to the compact integration of said at least two annular air / oil mixture separation devices into the accessory housing.

[0062] As illustrated in [Fig.3], the pinion 3 can be arranged axially between the first annular member 4a and the second annular member 4b. This configuration allows for a balanced mounting of the annular members on the tubular shaft on either side of the pinion.

[0063] Each annular organ 4a, 4b comprises an annular body 41a, 41b housing an annular filter 42a, 42b. It is understood in particular by two annular organs that the annular filters of each of the two annular organs are fluidically separated from each other.

[0064] Each annular body 41a,41b includes in particular a bottom wall extending radially and a radially external annular wall connected at an axial end to a radially external end of the bottom wall.

[0065] The annular filter 42a,42b may comprise a plurality of filter elements and the The annular body can form a plurality of circumferentially adjacent housings separated by radial walls of the annular body, each housing in the plurality of housings containing a filter element from the plurality of filter elements. The annular filter 42a, 42b can notably be made of a cross-linked foam or in a porous material.

[0066] Each annular body 4la,41b includes an air / oil mixture inlet 43a,43b, an oil outlet 44a,44b opening radially outside the annular body 41a,41b and a filtered air outlet 45a,45b opening radially inside the annular body.

[0067] The air / oil mixture inlet 43a,43b opens axially opposite the annular filter 42a,42b. The air / oil mixture inlet 43a,43b may in particular be arranged at an axial end of the annular body 4la,41b.

[0068] The air / oil mixture inlet 43a, 43b may have one or more air / oil mixture inlet ports, each of which may be annular. In particular, the air / oil mixture inlet may have a single air / oil mixture inlet port extending annularly from an axial end of the annular body 41a, 41b opposite the bottom wall of the annular body. Alternatively, the air / oil mixture inlet may have a plurality of air / oil mixture inlet ports distributed circumferentially around an axial end of the annular body 41a, 41b.

[0069] The oil outlet 44a, 44b may include one or more oil outlet ports, each of which may be annular. The oil outlet ports are distributed circumferentially on the radially external wall of the annular body 41a, 41b. The oil outlet ports may, in particular, form one or more annular rows of oil outlet ports, each annular row of oil outlet ports being axially spaced from the others.

[0070] The filtered air outlet 45a, 45b may have one or more filtered air outlets, each of which may be annular. The filtered air outlet is, in particular, arranged, at least partially, opposite one or more openings 22a, 22b of the tube shaft. The filtered air outlet may, in particular, form a filtered air outlet extending annularly opposite said one or more openings 22 of the tube shaft when the filtered air outlet has only one filtered air outlet. Alternatively, when the filtered air outlet has several filtered air outlets, the filtered air outlets may form one or more annular rows of filtered air outlets, each of the annular rows of filtered air outlets being axially spaced from the others.

[0071] In particular, each of the annular air / oil mixture separation organs is configured so that an air / oil mixture enters each annular organ through the corresponding air / oil mixture inlet, and is then driven into rotation within the annular organ so that the oil contained in the air / oil mixture is radially centrifuged out of the annular organ through the corresponding oil outlet and the filtered air exits radially inwards through the filtered air outlet.

[0072] Furthermore, the assembly may include means for air circulation so that air circulation exists between the air / oil mixture inlet of the annular body and the inside of the tubular shaft in operation.

[0073] Furthermore, with reference to figures 3, 4A, 4B and 5, the filtered air outlet 45a of the first annular organ 4a opens radially into the first channel 21.

[0074] Assembly 1 comprises a filtered airflow segregation device 5, in particular for segregating the filtered airflows originating respectively from the first and second annular elements. The segregation device is mounted radially inside the tubular shaft 2 and is rotationally fixed to the tubular shaft 2. The segregation device 5 comprises at least one second channel 51 extending axially and arranged radially outside the first channel 21. Said at least one second channel 51 is in fluidic communication upstream with the filtered air outlet 45b of one of said at least one annular element, in particular the second annular element 4b, and in particular downstream with the first channel 21. In particular, the filtered air outlet 45b of the second annular element 4b opens radially into said at least one second channel 51.

[0075] The second channel 51 is notably delimited axially by an upstream axial end 52 that is closed and by a downstream axial end 53 opening onto the first channel 21.

[0076] In particular, the second channel 51 opens axially and advantageously downstream, in particular from the second annular organ, into the first channel 21.

[0077] By implementing two separate annular air / oil mixture separation devices, the present disclosure provides at least two different paths for filtering the air / oil mixture. This configuration thus increases the air passage area and consequently reduces the pressure losses of the assembly, and more generally of the turbomachine. Furthermore, the present disclosure increases the compactness of the means implemented for separating an air / oil mixture thanks to the compact integration of said at least two annular air / oil mixture separation devices into the accessory housing.

[0078] Furthermore, the implementation of the filtered airflow segregation device further improves the performance of the air / oil mixture filtration by the two annular elements. Indeed, performing fluidic separation of the filtered air exiting each annular element limits the impact of the air / oil mixture being drawn through the second annular element on the air / oil mixture being drawn through the first annular element. Consequently, such a configuration reduces the overall pressure drop.

[0079] Advantageously, the segregation device 5 is formed as a single unit with the tubular shaft.

[0080] Alternatively, the segregation device 5 can be a separate part of the tubular shaft 2 intended to be mounted radially inside the tubular shaft 2. This feature advantageously facilitates the implementation and maintenance of the segregation device.

[0081] More specifically, the segregation device 5 comprises a radially internal annular ring 54 and a radially external annular ring 55 coaxial with each other, delimiting the second channel 51. The radially internal annular ring forms, in particular, a wall radially delimiting the first and second channels. The radially external annular ring 55 can, in particular, be mounted against a wall 24 of the first channel 21.

[0082] The segregation device 5 includes, in particular, a circumferential bottom wall 60 connecting the radially external annular ferrule 55 to the radially internal annular ferrule 54. The circumferential bottom wall 60 is arranged, in particular, at the upstream axial end 52 of the second channel. This wall closes off the second channel at its upstream axial end. The circumferential bottom wall 60 may, in particular, include, at its upstream end, a surface inclined from upstream to downstream, so as to facilitate the flow of air filtered by the first annular element 4a.

[0083] The radially external annular ferrule 54 advantageously comprises at least one first opening 56 radially opposite the filtered air outlet 45b of the second annular member 4b. The filtered air exiting the filtered air outlet of the second annular member can thus radially pass through said at least one first opening in order to exit radially into the second channel.

[0084] The radially external annular ferrule 55 may in particular include a plurality of first openings 56. A number of first openings is preferably equal to a number of filtered air outlet orifices of the second annular organ 4b.

[0085] Furthermore, the segregation device may include a plurality of second channels 51 distributed circumferentially, preferably regularly, around the axis of rotation X. The number of second channels 51 is preferably equal to the number of filtered air outlets of the second annular organ 4b. For example, the segregation device may include between 6 and 10 second channels.

[0086] The segregation device may, in particular, include first radial walls 58 extending axially and radially between the internal radially oriented annular ferrule 54 and the external radially oriented annular ferrule 55 and circumferentially delimiting the second channels 51 from one another. The implementation of the first radial walls 58 makes it possible, in particular, on the one hand, to improve the mechanical strength of the segregation device, and on the other hand, to guide the flow axially in the second channels.

[0087] Advantageously, the radially external annular ferrule 55 extends axially upstream beyond the filtered air outlet 45a of the first annular member 4a. The radially external annular ferrule 55 includes, in particular, at least one second opening 57 radially opposite the filtered air outlet 45a of the first annular member 4a. The filtered air exiting the filtered air outlet of the first annular member can thus radially pass through said at least one second opening in order to exit radially into the first channel. This configuration of the radially external annular ferrule improves the retention of the segregation device within the tubular shaft.

[0088] The radially external annular ferrule 55 may in particular include a plurality of second openings 57. A number of second openings 57 is preferably equal to a number of filtered air outlet orifices 45a of the first annular organ 4a.

[0089] The segregation device 5 may include radial guide fins 59 extending axially and radially inwards from the radially external annular ferrule 55, at the periphery of the second openings 57. The implementation of the radial guide fins 59 makes it possible, on the one hand, to improve the mechanical strength of the segregation device, and on the other hand, to guide the flow of filtered air radially towards the first channel.

[0090] The radial guide fins 59 can in particular be connected to the circumferential bottom wall 60 of the segregation device.

[0091] Each of the radial guide fins 59 may include a radially internal end opposite the radially external annular ferrule 55. The radially internal end of the radial guide fins 59 is free.

[0092] The radially internal end of the radial guide fins 59 is advantageously arranged substantially in the same radial position as the radially internal annular ferrule 54. This arrangement allows the filtered air exiting the first annular member to be guided radially, initially, to the level of the radially internal annular ferrule 54, and then axially towards the interior of the radially internal annular ferrule.

Claims

Claims

1. Assembly (1) for an accessory housing of a turbomachine, the assembly (1) comprising: - a tubular shaft (2) intended to be driven in rotation about an axis of rotation (X) and comprising a first internal tubular channel (21) coaxial with the tubular shaft (2), - a pinion (3) coupled in rotation to the tubular shaft (2), and - at least one annular member (4a, 4b) for separating the air / oil mixture arranged around the tubular shaft (2) and integral in rotation with the tubular shaft (2), said at least one annular member (4a, 4b) comprising an annular body (41a, 41b) housing an annular filter (42a, 42b), each annular body (41a, 41b) comprising an air / oil mixture inlet (43a, 43b), an oil outlet (44a, 44b) opening radially to the exterior of the annular body (41a, 41b) and a filtered air outlet (45a, 45b) opening radially inside the annular body (41a, 41b),wherein the assembly (1) comprises a device (5) for segregating the filtered air flows, the segregation device (5) being mounted radially inside the tubular shaft (2) and being mounted so as to rotate with the tubular shaft (2), the segregation device (5) comprising at least one second channel (51) extending axially and being arranged radially outside the first channel (21), said at least one second channel (51) being in fluid communication upstream with the filtered air outlet (45b) of one of said at least one annular member (4a, 4b).,

2. Assembly (1) according to claim 1, comprising a first annular member (4a) and a second annular member (4b) for separating the air / oil mixture.

3. Assembly (1) according to claim 2, in which the first annular member (4a) is arranged upstream of the second annular member (4b) in a direction of flow of filtered air in the first channel (21), the filtered air outlet (45a) of the first annular member (4a) opening radially into the first channel (21), said at least one second channel (51) being in fluid communication upstream with the filtered air outlet (45b) of the second annular member (4b) and downstream with the first channel (21).

4. Assembly (1) according to one of the preceding claims combined with the claim 2, wherein the second channel (51) opens axially downstream of the second annular member (4b) into the first channel (21).

5. Assembly (1) according to one of the preceding claims, in which the segregation device (5) comprises a radially internal annular ferrule (54) and a radially external annular ferrule (55) coaxial and delimiting between them the second channel (51), the radially external annular ferrule (54) comprising at least a first opening (56) radially opposite the filtered air outlet (45b) of the second annular member (4b).

6. Assembly (1) according to claim 5 combined with claim 2, in which the radially external annular ferrule (55) extends axially upstream beyond the filtered air outlet (45a) of the first annular member (4a), the radially external annular ferrule (55) comprising at least one second opening (57) radially opposite the filtered air outlet (45a) of the first annular member (4a).

7. Assembly (1) according to one of the preceding claims, in which the segregation device (5) comprises a plurality of second channels (51) distributed circumferentially, preferably regularly, around the axis of rotation (X).

8. Assembly (1) according to claim 7 combined with claim 2, wherein the filtered air outlet (45b) of the second annular member (4b) comprises a plurality of filtered air outlet orifices, the number of second channels (51) being equal to the number of filtered air outlet orifices of the second annular member (4b).

9. Assembly (1) according to one of the preceding claims, in which the segregation device (5) is formed in one piece with the tubular shaft (2).

10. Assembly (1) according to one of claims 1 to 8, in which the segregation device (5) is a part separate from the tubular shaft (2) intended to be mounted radially inside the tubular shaft (2).

11. Assembly (1) according to one of the preceding claims combined with claim 2, in which the pinion (3) is arranged axially between the first annular member (4a) and the second annular member (4b).

12. Accessory housing for a turbomachine comprising an assembly (1) according to one of the preceding claims.

13. Turbomachine comprising an accessory housing according to claim previous instruction.

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