A method for manufacturing a device for transferring fluid, comprising measures for protecting a seal against an edge formed by an outlet orifice of a tubular channel.
The protective tool method addresses seal damage in fluid transfer devices by shielding the seal during assembly, improving turbomachinery performance and reducing environmental impact.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2024-06-20
- Publication Date
- 2026-05-08
AI Technical Summary
Existing fluid transfer devices, particularly in turbomachinery for aircraft propulsion, face issues with compressible seals being damaged during assembly due to contact with the edge of an outlet orifice, leading to bulkiness and performance penalties.
A method involving the use of a protective tool to shield the compressible seal during installation, preventing it from striking the edge of the tubular channel outlet, ensuring the seal's integrity and enabling smooth assembly.
The method protects the compressible seal from damage, reducing the risk of assembly failures and enhancing the overall performance and environmental impact of turbomachinery.
Smart Images
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Abstract
Description
Title of the invention: Method for manufacturing a device for transferring fluid comprising measures for protecting a seal against an edge formed by an outlet orifice of a tubular channel. Technical field
[0001] The present invention relates to the field of fluid transfer devices, and more particularly to the manufacture of devices for which a compressible seal may be damaged by contact with the edge of an orifice during the assembly of the elements constituting such devices.
[0002] Such a device may in particular be part of a system designed to transfer several fluid paths from a fixed structure to a rotating structure, or more generally between two structures in relative rotation with respect to each other.
[0003] In specific application examples in the field of turbomachinery for aircraft propulsion, the stationary structure may be defined by a stator of such a turbomachine, while the rotating structure may be defined by its rotor. In such applications, the fluid is, for example, oil, or another fluid, intended for the fluidic control of actuators. In specific applications, the system under consideration is of the type commonly referred to as an OTB (from the Anglo-Saxon terminology "Oil Transfer Bearing"), and is, for example, intended to supply a cylinder controlling the pitch of one or more propeller blades, as well as a blade safety actuator. Prior art
[0004] Multi-way fluid transfer systems between two structures in relative rotation, such as those intended for the control of actuators within turbomachinery for aircraft propulsion, are generally bulky and heavy, which penalizes the overall performance of turbomachinery and results in a negative impact on climate change.
[0005] There is therefore a need for an improved multi-way fluid transfer system.
[0006] In the context of developing such a system, a problem arises with regard to concerns a device for transferring fluid, the manufacture of which requires: • to provide (or manufacture) an external part, having a cylindrical internal surface delimiting a housing having an open axial end, the external part comprising a tubular channel having an outlet opening through the aforementioned internal surface; and • provide an internal part having an external surface with a groove in which a compressible seal is housed; then • Insert the inner part through the open axial end of the housing defined by the outer part, and move the inner part in axial translation within the housing by sliding the compressible seal against the inner surface of the outer part, until the compressible seal is brought beyond the outlet of the tubular channel.
[0007] Indeed, there appears to be a risk of damage to the compressible seal in contact with an edge formed by a contour of the outlet of the tubular channel defined in the internal surface of the external part, during the axial movement of the internal part along the internal surface of the external part.
[0008] Such a problem can of course arise with fluid transfer devices in contexts other than that of multi-way fluid transfer systems between two frames in relative rotation.
[0009] The present invention generally aims to remedy this problem and is the result of technological research conducted by the Applicant, aimed at significantly improving aircraft performance. In this respect, the invention contributes to reducing the environmental impact of aircraft. Description of the invention
[0010] The invention proposes for this purpose a method for manufacturing a device for transferring fluid, the method comprising at least steps consisting of: • SA) to provide an external part, having an internal surface cylindrical in shape along an axis and defining a housing having an open axial end, the external part comprising a tubular channel having an outlet opening through said internal surface; and to provide an internal part having an external surface shaped so that the internal part can be inserted into the housing, the external surface having a groove in which is housed a compressible seal which thus surrounds said external surface; then • SB) mount, in the tubular canal, a protective tool, so that a distal end of the latter is entirely surrounded by an edge formed by a contour of the tubular canal outlet defined in the internal surface of the external part; then • SC) Insert the inner part through the open axial end of the housing defined by the outer part, and move the inner part axially within the housing by sliding the compressible seal against the inner surface of the outer part and against the distal end of the protective tool, until the compressible seal is brought beyond the outlet of the tubular channel, a step during which the distal end of the protective tool prevents the compressible seal from axially striking the edge formed by the contour of the tubular channel outlet; then • SD) remove the protective tool from the tubular channel.
[0011] The method according to the invention thus allows protection of the compressible seal against risks of damage by the edge defined by the contour of the outlet of the tubular channel, during the installation of the seal.
[0012] In preferred embodiments of the invention, the distal end of the protective tool has a terminal surface recreating a profile of the internal surface of the external part at the outlet of the tubular channel.
[0013] In preferred embodiments of the invention, the tubular channel is a straight channel and the protective tool has a straight shape.
[0014] In preferred embodiments of the invention, step SA includes providing a part intended to form the external part, and then drilling the tubular channel through an external wall of said part.
[0015] In preferred embodiments of the invention, the method comprises, after step SD, a step SE consisting of placing a plug so as to seal a radially external end of the tubular channel.
[0016] In preferred embodiments of the invention, the external part and the internal part are such that at the end of step SD: • the internal surface of the external part and the external surface of the internal part define between them a first transfer channel closed axially by the compressible seal and extending axially beyond the latter in the direction opposite to the open axial end of the housing; • the internal part defines a second transfer channel extending concentrically to the first transfer channel and communicating with the tubular channel via a passage orifice opening through the external surface of the internal part.
[0017] In preferred embodiments of the invention, the external part comprises a first tubular inlet and a second tubular inlet such that at the end of step SD, the first tubular inlet is connected to the first transfer channel, and the second tubular inlet is connected to the second transfer channel via the tubular channel.
[0018] In preferred embodiments of the invention, the internal part defines a third, tubular-shaped transfer channel around which the second transfer channel extends, and having, at the end of step SD, an axial end making protruding out of the housing through the open axial end of the housing and forming a third tubular entrance.
[0019] The invention also relates to a system for transferring multiple fluid pathways between two structures rotating relative to each other, comprising: • a central part intended to be integral with one of the two structures, the central part being made up of the device manufactured by means of a process of the type defined above, the external part of which defines an external surface of the central part, with geometry of revolution around the axis, and whose tubular inlets constitute fluidic inlets of the system; • a peripheral part intended to be integral with the other of the two structures, the peripheral part having an internal surface with geometry of revolution around the axis arranged around the external surface of the central part with the ability to rotate relative to the latter around the axis; • transfer chambers defined between the external surface of the central part and the internal surface of the peripheral part;
[0020] in which: • the device constituting the central part comprises, for each of said transfer channels, at least one fluidic branch connected to the transfer channel in question and opening through the external surface of the central part into a corresponding transfer chamber, so that the device respectively puts the fluidic inlets of the system into fluidic communication with the transfer chambers; and • the peripheral part is configured to connect respectively fluidic outlets of the system to the transfer chambers through said internal surface of the peripheral part.
[0021] The invention also relates to an aircraft turbomachine, comprising at least one system of the type defined above, and comprising a stator attached to one of the central and peripheral parts of the system and a rotor attached to the other of the central and peripheral parts of the system.
[0022] The invention also relates to a method for manufacturing a system of the type defined above, comprising at least steps consisting of: • manufacture the device intended to constitute the central part using a process of the type defined above, and make the peripheral part available; then • mount the peripheral part around the central part in such a way as to allow relative rotation between these two parts. Brief description of the drawings
[0023] The invention will be better understood, and other details, advantages and features thereof will become apparent from the following description, given by way of non-limiting example and with reference to the accompanying drawings in which:
[0024] [Fig-1] is a flowchart of a process for manufacturing a device for transferring fluid, according to a preferred embodiment of the invention;
[0025] [Fig.2] is a partial schematic axial cross-sectional view of elements intended to to constitute such a device, made available as part of a first step A of the process;
[0026] [Fig.3] is a view similar to [Fig.2], illustrating a later step B of the process;
[0027] [Fig.4] is a view similar to [Fig.3], illustrating a later step C of the process;
[0028] [Fig.5] is a view similar to [Fig.4], illustrating the device at the end of step C of the process;
[0029] [Fig.6] is a view similar to [Fig.5], illustrating a later step D of the process;
[0030] [Fig.7] is a view similar to [Fig.6], illustrating a later step E of the process;
[0031] [Fig.8] is a schematic axial cross-sectional view of the device, at the end of the process figures 1-7;
[0032] [Fig.9] is a view similar to [Fig.8], according to another cutting plane;
[0033] [Fig. 10] is a schematic axial cross-sectional view of a system for transferring several fluid paths between two structures rotating relative to each other, comprising the device of Figures 8 and 9;
[0034] [Fig. 11] is a schematic axial cross-sectional view of a turbomachine comprising a system such as that of [Fig. 10].
[0035] Throughout these figures, identical references may designate identical or analogous elements. Detailed presentation of preferred embodiments
[0036] A process for manufacturing a device 20 for transferring fluid will first be described with reference to Figures 2 to 7, and with constant reference to [Fig.1] which represents the flowchart of the process.
[0037] Firstly, a step SA of this process consists of making available an external part 210 and an internal part 212 ([Fig.2]) intended to form the device 20 once assembled together.
[0038] Generally, the external part 210 has an internal surface 214 that is cylindrical along an axis 8. The internal surface 214 of the external part delimits a housing 215 having an open axial end 216, on a first axial side SI of the device.
[0039] By "cylindrical", it is necessary to understand, in the mathematical sense, a ruled surface whose generatrices are parallel to the axis 8. In the illustrated example, the internal surface 214 is cylindrical in shape, but other cylindrical shapes are possible within the framework of the invention, the important thing being that the internal part 212 can slide in the housing 215, along the internal surface 214, as will become clearer in what follows.
[0040] Throughout this description, the axial direction X is the direction of axis 8. A cylindrical coordinate system centered on axis 8 is further considered, in which a radial direction R is at every point orthogonal to and passing through axis 8, while an orthoradial or circumferential direction C is, at every point, a direction locally orthogonal to the radial direction R and to axis 8. A transverse plane is a plane orthogonal to axis 8. The terms "internal" and "external" refer respectively to a relative proximity and a relative distance of an element from axis 8. Furthermore, the qualifier "axial" is used with reference to axis 8.
[0041] Furthermore, the external part 210 includes a tubular channel 218 having an outlet 220 opening through the internal surface 214. The contour of the outlet 220 forms an edge 220A. This edge 220A, which is generally difficult to smooth, may have a sharp character.
[0042] In the illustrated example, the tubular channel 218 is a straight channel, for example a radial channel, that is to say a channel oriented radially with respect to the axis 8.
[0043] Step SA includes, for example, the prior provision of a part intended to form the external part, then drilling the tubular channel 218 through an external wall 221 of the part, so as to obtain the external part 210.
[0044] The inner part 212 has an outer surface 222 shaped so that the inner part can be inserted into the housing 215 defined by the outer part. For this purpose, the outer surface 222 of the inner part is preferably cylindrical in shape with a cross-section homothetic to the cross-section of the inner surface 214 of the outer part 210.
[0045] Furthermore, the external surface 222 of the internal part has a groove 224. A compressible seal 226 is housed in the groove 224 so that the compressible seal 226 surrounds the external surface 222.
[0046] In the illustrated example, in which the internal surface 214 of the external part is cylindrical in shape, the external surface 222 of the internal part 212 is therefore also cylindrical in shape, and the groove 224 and the compressible seal 226 are annular in shape.
[0047] In the context of this process, a protective tool 230 is further provided, shaped to be able to be inserted into the tubular channel 218, and having a distal end 232.
[0048] In the case where the tubular channel 218 is straight in shape, the protective tool 230 also has a straight shape.
[0049] For more complex shapes of the tubular channel, including one or more curved portion(s), the protective tool 230 can be designed to be flexible and thus conform to the curved portion(s).
[0050] Preferably, the protective tool 230 is at least partially made of Teflon or any other material having good anti-adhesion properties, at least at the distal end 232 of the tool.
[0051] Step SB of the process then consists of mounting the protective tool 230 in the tubular channel 218 ([Fig. 3]) such that the distal end 232 of the protective tool 230 is completely surrounded by the edge 220A formed by the contour of the outlet 220 of the tubular channel 218, while allowing the internal part 212 to be inserted axially into the housing 215 beyond the outlet 220 of the tubular channel 218, as will become clearer in what follows. For this purpose, it should be understood that the distal end 232 of the tool is flush with the internal surface 214 of the external part or protrudes slightly beyond it towards the interior of the housing 215.
[0052] Step SC of the process then consists of inserting the inner part 212 through the open axial end 216 of the housing 215, and moving the inner part 212 in axial translation in the housing 215 by sliding the compressible seal 226 against the inner surface 214 of the outer part ([Fig.4]), until the compressible seal 226 is brought beyond the outlet 220 of the tubular channel 218 ([Fig.5]).
[0053] During this SC step, the distal end 232 of the protective tool 230 prevents the compressible seal 226 from axially striking the edge 220A defined by the contour of the outlet 220 of the tubular channel 218.
[0054] The protective tool 230 thus protects the compressible seal 226 against risks of damage by the edge 220A during the installation of the internal part 212.
[0055] In the preferred embodiment of the invention, the distal end 232 of the protective tool has a terminal surface 233 shaped to reconstitute a profile of the internal surface 214 of the external part at the outlet 220 of the tubular channel 218, when the protective tool 230 is in place in the tubular channel 218. In other words, the terminal surface 233 of the tool creates substantially a continuity of the internal surface 214 at the outlet of the tubular channel 218, and is shaped so as to fit within the cylindrical profile of the internal surface 214. The internal geometry of the housing 215 is thus not affected by the presence of the protective tool. 230, so that the axial translation of the internal part 212 within the housing 215 can be optimally achieved. Means for angular orientation and error correction of the protective tool 230 within the tubular channel 218 can be provided to facilitate tool placement and ensure that its terminal surface 233 assumes the correct position.
[0056] At the end of step SC ([Fig.5]), the compressible seal 226 is therefore applied against the internal surface 214 of the external part 210, in a position located beyond the outlet 220 of the tubular channel 218 towards the interior of the housing 215, that is to say from a second axial side S2 opposite to the first axial side SI.
[0057] The compressible seal 226 thus makes it possible to separate, in a watertight manner, two annular fluid passages defined each between the internal surface 214 of the external part 210 and the external surface 222 of the internal part 212.
[0058] A first of these two fluid passages 234 is defined between the compressible joint 226 and the open axial end 216 of the housing 215, while the other passage, which defines a first transfer channel 36A according to the terminology adopted in this disclosure, is closed axially by the compressible joint 226 and extends axially beyond this joint in the direction of the second axial side S2.
[0059] The SD step of the process finally consists of removing the protective tool 230 out of the tubular channel 218 ([Fig.6]).
[0060] At the end of this step, the outlet 220 of the tubular channel 218 opens into the first fluid passage 234 mentioned above.
[0061] In the illustrated example, the device 20 comprises a tubular fluid inlet 14B formed in the external portion 210 and opening into the tubular channel 218, for example parallel to the axis 8, between a radially external end 236 of the tubular channel and the outlet 220 of the tubular channel. Fluid is thus not admitted into the tubular channel 218 through the radially external end 236 of the tubular channel, but through the tubular fluid inlet 14B.
[0062] In such a case where the admission of fluid into the tubular channel 218 is carried out by a means other than by the radially external end 236 thereof, the process advantageously includes, after the step SD, a step SE consisting of putting in place a plug 240 so that the latter closes this radially external end 236 ([Fig.7]).
[0063] Figures 8 and 9 illustrate more fully the device 20 in the context of a particular application of the invention.
[0064] As can be seen more clearly in these figures, the internal part 212 comprises a central tube 212A, for example with a circular cross-section, and a sleeve 212B, for example with a cylindrical shape of revolution, which surrounds the central tube 212A. The central tube 212A and the sleeve 212B are, for example, respectively attached to flanges 213A, 213B by which these elements are fixed to a corresponding flange 211 of the external part 210, for example by means of fasteners (not shown) such as bolts.
[0065] As shown in particular in [Fig.8], the internal part 212 defines a second transfer channel 36B extending concentrically to the first transfer channel 36A, for example between the central tube 212A and the sleeve 212B, and communicating with the first fluid passage 234, and therefore with the tubular channel 218, via a passage orifice 242 formed through the sleeve 212B so that this orifice opens through the external surface 222 of the internal part 212, preferably opposite the outlet 220 of the tubular channel 218.
[0066] Furthermore, with reference to [Fig. 9], the external portion 210 comprises a first tubular inlet 14A connected to the first transfer channel 36A, for example, via another tubular channel 250. Like the tubular channel 218, the other tubular channel 250 is, for example, also a straight channel, for example, a radial channel. The first tubular inlet 14A thus opens into the tubular channel 250, for example, axially, between a radially external end of this tubular channel and a radially internal outlet 252 of this tubular channel. Fluid is therefore not admitted into this tubular channel 250 through its radially external end, but through the first tubular fluid inlet 14A. This other tubular channel 250 can be made by drilling radially through the same wall of the external portion 210 as the tubular channel 218.Furthermore, another plug 256 can be placed in the radially external end of this other tubular channel 250 in order to obturate this end.
[0067] The tubular inlet 14B described above with reference to Figures 2-7 constitutes a second tubular inlet of the device, which is therefore connected to the second transfer channel 36B via the tubular channel 218, the first fluid passage 234, and the passage orifice 242 ([Fig.8]).
[0068] Furthermore, the internal part 212 defines a third tubular transfer channel 36C, around which the second transfer channel 36B extends, and having an axial end projecting out of the housing 215 defined by the external part 210, through the open axial end 216 of the housing 215, and forming a third tubular inlet 14C. In the illustrated example, this third transfer channel 36C is defined by the central tube 212A, at the center of the internal part 212.
[0069] The transfer channels 36A-36C are thus concentric channels extending along axis 8.
[0070] Furthermore, still with reference to figures 8 and 9, the external part 210 defines an external surface 20A of the device, which has a geometry of revolution about the axis 8. The external surface 20A surrounds all the transfer channels 36A-36C.
[0071] The external part 210 further defines a trunnion 34 at its end located on the second axial side S2 (that is to say on the side opposite to the open axial end 216 of the housing 215).
[0072] On the second axial side S2 (i.e., on the side of the trunnion 34), the transfer channels 36A-36C have staggered ends 39A-39C along the axis 8 (Figures 8 and 9) such that the further a channel is located from the axis 8, the less it extends towards the second axial side S2 (and, in this case, the shorter this channel is). Thus, the third channel 36C is the channel that extends furthest towards the trunnion 34, while the first channel 36A is the channel that extends the least towards the trunnion 34. In the illustrated example, the first channel 36A is delimited, in the direction of the second axial side S2, by a compressible annular joint 40A interposed between the surfaces 222 and 214.Similarly, the second channel 36B is delimited, in the direction of the second axial side S2, by a compressible annular joint 40B interposed between one end of the central tube 212A protruding beyond the sleeve 212B in the direction of the second axial side S2, and the external part 210.
[0073] In addition, the device 20 includes, for each of the transfer channels 36A to 36C, at least one fluidic branch 38A-38C connected to the transfer channel in question and opening through the external surface 20A of the device.
[0074] In the preferred example illustrated, the device 20 comprises, for each transfer channel 36A-36C, a corresponding series of fluidic connections 38A-38C, each having an internal end connected to the transfer channel 36A-36C in question and an external end opening through the external surface 20A. The fluidic connections of each series 38A-38C thus originate from the corresponding transfer channel 36A-36C.
[0075] For this purpose, for each of the transfer channels 36A-36C, the fluidic branch(es) 38A-38C connected to it extend(s) beyond any other transfer channel formed around the transfer channel considered, in the direction of the second axial side S2.
[0076] The fluidic connections 38A-38C of each series are, for example, arranged in the form of an annular row of fluidic connections regularly distributed around the axis 8. The fluidic connections 38A-38C preferably extend each in the radial direction R.
[0077] The device 20 of figures 8 and 9 is intended to form the central part of a system 10 intended for the transfer of several fluid paths, for example three in number, between two structures in relative rotation with respect to each other.
[0078] With reference to [Fig. 10], such a system therefore comprises the central part consisting of the device 20 and intended to be attached to one of the structures, such as a turbomachine stator. The tubular inlets 14A-14C of the device 20 constitute respectively fluidic inlets for system 10, intended respectively for the different fluid paths to be transferred.
[0079] Such a system 10 further comprises a peripheral part 22 intended to be integral with the other structure, such as a turbomachine rotor. This peripheral part 22 has an internal surface 22A with a geometry of revolution about the axis 8, arranged around the external surface 20A of the central part with the ability to rotate relative to the latter about the axis 8. The internal surface 22A can be defined by several elements constituting the peripheral part 22 and may, therefore, have discontinuities.
[0080] Such a system 10 further comprises transfer chambers 24A-24C defined between the external surface 20A of the central part and the internal surface 22A of the peripheral part to allow each the transfer of fluid between the central part 20 and the peripheral part 22.
[0081] The fluidic connections 38A-38C (or the series of fluidic connections 38A-38C) are arranged so as to put the transfer channels 36A-36C of the system in fluidic communication with the transfer chambers 24A-24C respectively.
[0082] Thus, the device 20 puts the fluidic inputs 14A-14C of the system into fluidic communication with the transfer chambers 24A-24C.
[0083] Furthermore, the peripheral part 22 is configured to connect fluidic outlets of the system 16A-16C to the transfer chambers 24A-24C, respectively, through the internal surface 22A of the peripheral part 22. The means for achieving such a result will not be described here and are unrelated to the invention. An example of a configuration for the peripheral part is given, for example, in the patent application filed in France on October 20, 2023, under number FR2311395.
[0084] To connect the central part 20 and peripheral part 22 by allowing rotational guidance of one relative to the other, the system 10 includes at least one bearing 110A, 110B radially interposed between the central part 20 and the peripheral part 22, for example two such bearings 110A, 110B arranged axially on either side of the set of transfer chambers 24A to 24C.
[0085] Furthermore, a manufacturing process for system 10 generally comprises the steps of: • manufacture, using the process described above, the device intended to constitute the central part 20, and make available the peripheral part 22; then • mount the peripheral part 22 around the central part 20 so as to allow relative rotation between these two parts.
[0086] The mounting of the peripheral part 22 around the central part 20 is of course carried out in such a way as to connect the fluid connections 38A-38C with the fluidic outlets defined by the peripheral part 22, respectively via the transfer chambers 24A-24C.
[0087] A method for implementing a system of the type described above generally comprises: • selective fluid supply to the 14A-14C fluidic inlets of the system; • the circulation of the fluid in the central part 20 up to the transfer chambers 24A-24C; • the circulation of the fluid in the peripheral part 22 from the transfer chambers 24A-24C, up to the fluid outlets of the system.
[0088] Fig. 11 illustrates a turbomachine 310, for example a twin-spool turbofan engine for aircraft, generally comprising a fan 312 for the intake of an airflow Fl which divides downstream of the fan into a primary flow F2 flowing in a primary flow channel, hereinafter referred to as the primary flow PV, and a secondary flow F3 flowing in a secondary flow channel, hereinafter referred to as the secondary flow SV, arranged around the primary flow PV.
[0089] The turbomachine comprises, for example, a low-pressure compressor 314, a high-pressure compressor 316, a combustion chamber 318, a high-pressure turbine 320, and a low-pressure turbine 322, which together define the primary flow PV. The respective rotors of the high-pressure compressor and the high-pressure turbine are connected by a shaft called the "high-pressure shaft," while the respective rotors of the low-pressure compressor and the low-pressure turbine are connected by a shaft called the "low-pressure shaft," in a well-known manner. These rotors are mounted to rotate about a shaft 328 of the turbomachine.
[0090] The turbomachine includes a system 10 of the type described above, with axis 8 for example coinciding with axis 328 of the turbomachine 310.
[0091] A stator of the turbomachine is attached to one of the central 20 and peripheral 22 parts of the system, in this case the central part 20. A rotor of the turbomachine is attached to the other part, in this case the peripheral part 22, of the system.
[0092] The system 10, illustrated schematically in [Fig. 11], is arranged, for example, so that its fluidic outlets are connected to fluidic chambers of actuators mounted on the aforementioned rotor to enable the control of these actuators. In particular, the system is, for example, of the type commonly known as OTB (Oil Transfer Bearing) and is designed to supply a cylinder controlling the pitch of one or more propeller blades, as well as a blade safety actuator.
Claims
1. Demands A method for manufacturing a device (20) for transferring fluid, the method comprising at least steps consisting of: • SA) to provide an external part (210), having an internal surface (214) cylindrical in shape along an axis (8) and defining a housing (215) having an open axial end (216), the external part comprising a tubular channel (218) having an outlet (220) opening through said internal surface (214); and to provide an internal part (212) having an external surface (222) shaped so that the internal part (212) can be inserted into the housing (215), the external surface (222) having a groove (224) in which a compressible seal (226) is housed, thus surrounding said external surface (222); then • SB) mount, in the tubular channel (218), a protective tool (230), so that a distal end (232) of the latter is entirely surrounded by an edge (220A) formed by a contour of the outlet (220) of the tubular channel defined in the internal surface (214) of the external part (210); then • SC) insert the inner part (212) through the open axial end (216) of the housing (215) defined by the outer part (210), and move the inner part (212) axially within the housing (215) by sliding the compressible seal (226) against the inner surface (214) of the outer part (210) and against the distal end (232) of the protective tool (230), until the compressible seal (226) is brought beyond the outlet (220) of the tubular channel (218), a step during which the distal end (232) of the protective tool (230) prevents the compressible seal (226) from axially striking the edge (220A) formed by the contour of the outlet (220) of the tubular channel (218); then • SD) remove the protective tool (230) from the tubular channel (218).
2. A method according to claim 1, wherein the distal end (232) of the protective tool (230) has a terminal surface (233) reconstructing a profile of the internal surface (214) of the external part (210) at the outlet (220) of the tubular channel (218).
3. Method according to claim 1 or 2, wherein the tubular channel (218) is a straight channel and the protective tool (230) has a straight shape.
4. A method according to claim 3, wherein step SA comprises making available a part intended to form the external part (210), and then drilling the tubular channel (218) through an external wall (221) of said part.
5. A method according to any one of claims 1 to 4, comprising, after step SD, a step SE consisting of placing a plug (240) so as to seal a radially external end of the tubular channel (218).
6. A method according to any one of claims 1 to 5, wherein the outer part (210) and the inner part (212) are such that at the end of step SD: • the inner surface (214) of the outer part (210) and the outer surface (222) of the inner part (212) define between them a first transfer channel (36A) closed axially by the compressible seal (226) and extending axially beyond the latter in the direction opposite to the open axial end (216) of the housing (215); • the inner part (212) defines a second transfer channel (36B) extending concentrically to the first transfer channel (36A) and communicating with the tubular channel (218) via a through orifice (242) opening through the outer surface (222) of the inner part (212).
7. Method according to claim 6, wherein the external part (210) comprises a first tubular inlet (14A) and a second tubular inlet (14B) such that at the end of step SD, the first tubular inlet (14A) is connected to the first transfer channel (36A), and the second tubular inlet (14B) is connected to the second transfer channel (36B) via the tubular channel (218).
8. Method according to claim 7, wherein the internal part (212) defines a third transfer channel (36C), tubular in shape, around which the second transfer channel (36B) extends, and having, at the end of step SD, an axial end protruding out of the housing (215) through the open axial end (216) of the housing and forming a third tubular inlet (14C).
9. System (10) for transferring several fluid paths between two structures rotating relative to each other, comprising: • a central part intended to be fixed to one of the two structures, the central part being made up of the device (20) manufactured by means of the process according to claim 8, the external part (210) of which defines an external surface (20A) of the central part, having a geometry of revolution about the axis (8), and whose tubular inlets (14A to 14C) constitute fluidic inlets of the system (10); • a peripheral part (22) intended to be fixed to the other of the two structures, the peripheral part (22) having an internal surface (22A) having a geometry of revolution about the axis (8) arranged around the external surface (20A) of the central part with the ability to rotate relative to the latter about the axis (8);• transfer chambers (24A to 24C) defined between the external surface (20A) of the central part and the internal surface (22A) of the peripheral part; wherein: • the device (20) constituting the central part comprises, for each of said transfer channels (36A to 36C), at least one fluidic branch (38) connected to the transfer channel in question and opening through the external surface (20A) of the central part into a corresponding transfer chamber (24A to 24C), such that the device (20) respectively puts the fluidic inlets of the system into fluidic communication with the transfer chambers (24A to 24C); and; • the peripheral part (22) is configured to connect respectively fluidic outlets (16A to 16C) of the system to the transfer chambers (24A to 24C) through said internal surface (22A) of the peripheral part (22).
10. Aircraft turbomachine (310), comprising at least one system (10) according to claim 9, and comprising a stator integral with one of the central (20) and peripheral (22) parts of the system and a rotor integral with the other of the central (20) and peripheral (22) parts of the system.
11. A method for manufacturing a system (10) according to claim 9, comprising at least steps of: • manufacturing the device (20) intended to constitute the central part by means of the method according to claim 8, and making available the peripheral part (22); then • mounting the peripheral part (22) around the central part (20) so as to allow relative rotation between these two parts.