Ferrule segment

Abstract

The invention relates to a ferrule segment (20) adapted to delimit a portion of a turbomachine duct, characterized in that it comprises, on a first face (201, 241), a sealing plate (10) movably mounted to slide between a first position and a second position, said sealing plate (10) being adapted to be selectively fixed to the ferrule segment (20) in the second position in which the sealing plate protrudes from a lateral edge of the ferrule segment (20) to cover a junction between the ferrule segment and a structural arm (50) of the turbomachine. Figure for the abstract: Fig 5

Description

Title of the invention: Ferrule segment technical field

[0001] The field of the invention is that of aircraft turbomachinery. The invention relates more particularly to a ferrule segment for a structural arm, more particularly a structural arm arranged in a duct of an airflow, and to a method of assembling such a ferrule segment on a structural arm. State of the art

[0002] An aircraft is known to comprise one or more turbomachines for propulsion. A turbomachine includes a primary runner through which an airflow for the combustion chamber flows and a secondary runner through which an airflow for propulsion flows. A triple-flow turbomachine further comprises a tertiary runner. The airflow in the tertiary runner is separate from the secondary flow and may converge with and / or diverge from the primary flow. A triple-flow turbomachine is, for example, described in patent application WO 2023 / 099527 AL. Generally, each runner is a fixed part, i.e., it does not rotate during the operation of the turbomachine.

[0003] The tertiary vein is typically annular and circumferentially contained around a longitudinal axis of the turbomachine by a ferrule. Such a ferrule extends discontinuously over 360° around the longitudinal axis of the vein and is divided into several angular segments, for example into eight segments.

[0004] Each ferrule segment is made of a composite material and includes a metal coating on the radially internal faces of its upstream and downstream ends relative to the airflow circulating in the vein.

[0005] The tertiary vein may be traversed by structural arms extending radially within said vein. These structural arms delimit the angular sectors of the ferrule. A mechanical clearance of approximately 2 mm typically exists between the structure of an arm and the respective segment of the ferrule.

[0006] It is necessary to prevent fire penetration through this mechanical clearance. This implies ensuring a fire-tight seal between the structure of each arm and each segment of the shell, particularly the portion of the shell segment with a metal lining. However, during the turbomachine's service life, the shell sections must be disassembled regularly for maintenance and / or functional testing.

[0007] The space inside the vein is restricted and difficult to access, which limits the addition and attachment of elements to the ferrule.

[0008] One possible solution for ensuring fire tightness is to cover the gap between the arm and a ferrule segment with a cover plate fixed to the radially external face of the ferrule segment. However, such a cover plate creates a bulge in the third flow channel and therefore impacts the aerodynamic properties of the channel. For this reason, applying a cover plate to the radially external face is often incompatible with the geometry and / or kinematics of the channel.

[0009] Another possible solution is to fill the mechanical gap between mechanical parts by applying a fire-resistant polymer, followed by vulcanizing the polymer at room temperature. This method is known as RTV (an acronym for the English term "room temperature vulcanizing").

[0010] However, the RTV technique is time-consuming to implement and therefore impacts the assembly and disassembly time of the shell for maintenance or testing. In particular, it is necessary to remove the polymer completely during each disassembly, clean the shell and arm components, and reapply the polymer using RTV during assembly. Due to the numerous joints to be treated, there is also a risk of partial omission of the polymer during assembly. Furthermore, the polymer layer is susceptible to damage during operations on the turbomachine or during its use, thus resulting in a loss of fire tightness at the affected joint.

[0011] A third possible solution is the addition of a specific seal in the ferrule to ensure fire tightness. However, integrating such a seal into the groove is complex and makes assembling the ferrule segments difficult.

[0012] In conclusion, the methods for achieving fire tightness either have an impact on the aerodynamics of the vein, or make the assembly and disassembly of the ferrule longer and more complex. Description of the invention

[0013] An object of the invention is to provide a fire-sealing device for a ferrule arranged in a groove, facilitating the assembly and disassembly of the ferrule while ensuring adequate fire sealing for the safety of the turbomachine.

[0014] To this end, the invention proposes a ferrule segment adapted to delimit a portion of a turbomachine flow,

[0015] characterized in that it comprises, on a first face, a sealing plate mounted to slide movably between a first position and a second position,

[0016] said sealing plate being adapted to be selectively fixed to the ferrule segment in the second position in which the sealing plate protrudes relative to a lateral edge of the shell segment to cover a junction between the shell segment and a structural arm of the turbomachine.

[0017] The arrangement of the sealing plate inside the ferrule prevents modification of the outer wall of the arm and the third flow channel. The sliding, movable mounting allows the sealing plate to be moved to its final position after the ferrule has been assembled.

[0018] Preferably, the sealing plate is arranged on a first face of one end of the ferrule segment having a metal coating.

[0019] Advantageously, the sealing plate is removable from the ferrule segment.

[0020] Advantageously, the sealing plate has a fixing hole and an oblong hole, the ferrule segment having a first hole and a first fixing means adapted to pass through the first hole and the oblong hole of the sealing plate so as to keep the movable sealing plate sliding relative to the ferrule segment, the ferrule segment further having a second hole and a second fixing means adapted to pass through the second hole and the fixing hole of the sealing plate so as to fix the sealing plate in the second position.

[0021] Preferably, the first and / or second means of fixing is a countersunk screw and the first hole and / or second hole has a milling adapted to house the head of said countersunk screw in a second face opposite to the first face of the ferrule segment.

[0022] Advantageously, the sealing plate is made of metal, preferably steel or titanium.

[0023] The invention also relates to an aircraft turbomachine, comprising a shell forming at least partially an airflow channel, said shell comprising a plurality of segments as described above, said segments being delimited by a plurality of structural arms extending radially in the channel, each sealing plate being arranged to cover a junction between a shell segment and a respective structural arm.

[0024] Preferably, at least one sealing plate arranged on a ferrule segment covers, in the second position, a surface having a width of at least ten times the width of a mechanical clearance within the junction between a ferrule segment and a respective structural arm.

[0025] The invention also relates to a method for mounting a ferrule segment in a turbomachine comprising a structural arm extending in a channel, said method comprising the following steps: • the provision of at least one ferrule segment as described above, with the sealing plate in the first position; • the assembly of the ferrule segment in the turbomachine, a mechanical play occurring between the ferrule segment and the structural arm; • the movement of the sealing plate in a direction essentially parallel to an upstream or downstream edge 26 of the ferrule segment, so as to cover the junction between the ferrule segment and the arm; and • the fixing of the sealing plate in a fixed manner relative to the ferrule segment in the second position.

[0026] Preferably, in the second position, the sealing plate comes against a rib arranged on a first face of the arm opposite the vein and formed by a fold included in a sheet forming the arm, said fold forming a slot on a second face of the arm oriented towards the vein. Brief description of the figures

[0027] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the accompanying drawings, in which:

[0028] Fig. 1 illustrates the mechanical play between one end of a ferrule segment and a structural arm.

[0029] Fig. 2 is a view of a movable sealing plate in translation on a segment of the ferrule.

[0030] Fig. 3 is a view of a sealing plate covering the junction between a ferrule segment and a structural arm.

[0031] Fig. 4 is a cross-sectional view of a ferrule segment comprising a sealing plate and a portion of a structural arm.

[0032] Fig. 5 illustrates a first step in covering a mechanical gap between a ferrule segment and a structural arm.

[0033] Fig. 6 illustrates a sealing plate abutting a rib of the structural arm.

[0034] Fig. 7 illustrates a second stage of covering a mechanical gap between a ferrule segment and a structural arm. Detailed description of implementation methods

[0035] In the following description, the terms "internal" and "external" refer to positioning relative to the longitudinal axis X of a turbomachine. The radial direction is perpendicular to the longitudinal axis X. The terms "upstream" and "downstream" are to be understood in the direction of the airflow circulating in a duct.

[0036] The invention relates to a ferrule segment forming a portion of a wall of a turbomachine duct, for example a tertiary duct. The wall may be a radially internal or radially external wall of the duct. The ferrule segment has an edge upstream of the airflow in the vein, an edge downstream of said airflow, and two lateral edges extending essentially parallel to the direction of the airflow.

[0037] Figure 1 illustrates the upstream end of a ferrule segment 20. The ferrule segment 20 has, at its upstream and / or downstream ends, a metal coating 24 extending over a first face 201 of the ferrule segment. This first face 201 is opposite a second face forming the wall of the tertiary vein. The metal coating comprises a first free face 241 and a second face in surface contact with the ferrule segment.

[0038] The lateral edge 27 of the ferrule segment is essentially perpendicular to the upstream edge 26.

[0039] A structural arm 50 extends radially in the tertiary vein. A portion of the structural arm delimits the ferrule segment 20 at its lateral edge 27. During assembly of the ferrule segment 20, a mechanical clearance 52 occurs between the structural arm 50 and the lateral edge 27 of the ferrule segment. Typically, the mechanical clearance is approximately 2 mm.

[0040] In order to cover this mechanical play at its upstream and / or downstream ends, the ferrule segment according to the invention comprises one or more sealing plates.

[0041] For the sake of simplicity, we will now describe the arrangement of a sealing plate at an upstream end. However, the invention is not limited to the arrangement at the upstream edge. The sealing plate can be similarly positioned at the downstream edge of the ferrule segment or on another part of the ferrule having a metal coating. Likewise, the sealing plate can be positioned near each lateral edge of the ferrule segment.

[0042] Figure 2 schematically illustrates a ferrule segment comprising a plate sealing 10 at its upstream end. The sealing plate is mounted on the ferrule segment in a removable manner, i.e. it can be removed non-destructively using one or more known tools, for example a screwdriver or an adjustable wrench.

[0043] The sealing plate 10 is a metal plate, preferably made of steel or titanium. By way of illustration and without limitation, the sealing plate 10 has an essentially rectangular geometry with a first edge essentially parallel to the mechanical gap 52 between the structural arm 50 and the lateral edge 27 of the ferrule segment, and a second edge essentially parallel to the upstream edge 26 of the ferrule segment. Preferably, the sealing plate has a length of at least 20 mm in the direction of the upstream edge of the ferrule 26. This ensures sufficient fire tightness for the mechanical gap, which is approximately 2 mm wide.

[0044] The sealing plate 10 is in surface contact with the first face 241 of the metal coating of the ferrule segment 20 and is movable in sliding in a direction essentially parallel to the upstream edge 26 of the ferrule segment.

[0045] The ferrule segment and the metal cladding may have a curvature about the longitudinal axis of the vein, for example, such that the section perpendicular to the longitudinal axis of the ferrule segment corresponds to a circular segment. In this case, the sealing plate is preferably curved so that the curvature of the sealing plate corresponds to the curvature of the first face 241 of the metal cladding.

[0046] When the ferrule segment and the metal cladding have, with reference to [Fig.1], a fold 29 parallel to the upstream face of the ferrule segment, the sealing plate preferably includes a fold 19 illustrated in Figures 5 and 6. The fold 19 in the sealing plate corresponds to the fold 29 of the first face 241 of the metal cladding.

[0047] Thus, the plate is at least partially in surface contact with the first face 241 of the metal coating in all positions that the plate can adopt during its sliding.

[0048] The sealing plate is movable between a first position illustrated in [Fig.2], in which the entire surface of the sealing plate is in contact with the first face 201 of the ferrule segment and / or the first face 241 of the metal coating, and a second position illustrated in [Fig.3] in which the sealing plate protrudes from the lateral edge 27 of the ferrule segment.

[0049] In the first position, the sealing plate does not extend beyond the lateral edge 27 of the ferrule segment 20. The plate may be flush with the lateral edge 27 of the ferrule segment, or recessed relative to said lateral edge 27. Such a position of the sealing plate facilitates mounting the ferrule close to the structural arm. In some embodiments, the sealing plate may be locked in the first position and selectively unlocked to allow sliding between the first and second positions.

[0050] In the second position, with reference to [Fig. 3], part of the sealing plate extends beyond the lateral edge 27. Typically, about half of the sealing plate remains in surface contact with the ferrule segment. Thus, the sealing plate is positioned to cover the junction between the ferrule segment 20 and the structural arm 50 after the ferrule has been assembled. The second position therefore covers the mechanical gap 52 that exists between these elements after assembly.

[0051] The sealing plate is configured to be fixed in a fixed position. This fixing is reversible to facilitate disassembly of the ferrule segment.

[0052] In a preferred embodiment, the sealing plate includes an oblong hole 11 extending essentially parallel to the upstream edge 26 of the ferrule segment to allow sliding between the first and second positions. A first fastening means 31 is arranged in the ferrule segment at the oblong hole 11 to hold the sealing plate against the first face 241 of the metal cladding, allowing the fastening means to slide within the oblong hole. The sealing plate further includes a fastening hole 12, for example, of circular geometry. A second fastening means 32 can be removably arranged in the ferrule segment at the fastening hole 12 in the second position, allowing the sealing plate 10 to be fixed in the second position during the assembly of the ferrule segment.

[0053] Preferably, with reference to [Fig. 4], the ferrule segment has a first hole 21 in which a first screw 31 can be fitted. The first screw 31 is inserted from the face 202 of the ferrule segment forming the turbomachine's flow. The first screw 31 passes through the ferrule segment 20, the metal cladding 24, and the oblong hole 11 in the sealing plate 10. A nut 61 is screwed onto the end of the first screw 31 to secure the sealing plate to the screw. A washer 71 can be fitted between the sealing plate and the nut 61 to better distribute the nut's bearing surface on the face of the sealing plate and thus facilitate sliding in the oblong hole.

[0054] The ferrule segment further has a second hole 22 into which a second screw 32 can be inserted after the ferrule has been assembled in the turbomachine. The second hole 22 is positioned to correspond to the position of the mounting hole 12 in the sealing plate when the sealing plate is in the second position. The second screw 32 can be inserted from the face 202 of the ferrule segment forming the wall of the flow. After insertion into the second hole 22, the second screw 32 passes through the ferrule segment 20, the metal cladding 24, and the mounting hole 12 of the sealing plate 10. A nut 62 can be screwed onto the end of the second screw 32 to secure the sealing plate in the second position. A washer 72 can be placed between the sealing plate and the nut 62 to facilitate tightening the screw 32.

[0055] Advantageously, the first hole 21 and the second hole 22 each have a respective milling in the second face 202 of the ferrule segment forming the wall of the vein. The first screw 31 and the second screw 32 are countersunk screws whose heads are housed in the milling of the first hole 21 and the second hole 22.

[0056] The milling allows the screw heads to be inserted completely into each respective hole, thus preventing the screw head from protruding into the groove and disrupting the airflow.

[0057] In an advantageous embodiment, the first and second screws replace two respective rivets provided in the ferrule segment for attaching the metal liner. This allows the use of holes 31, 32 already present in the ferrule segment, simplifying the addition of the sealing plate to an existing ferrule segment without requiring additional drilling of the ferrule segment structure.

[0058] We will now describe the assembly of a ferrule segment comprising a sealing plate in an aircraft turbomachine.

[0059] The turbomachine includes structural arms traversing, for example, a vein, for example, the tertiary vein. A ferrule segment is fixed in the turbomachine such that the second face 202 of said ferrule segment 20 forms a portion of a wall of said vein. Mechanical clearance occurs between a portion of a structural arm 50 and the ferrule segment 20.

[0060] The ferrule segment 20 has, on its first face 201 opposite the second face 202 forming the wall of the vein, a sealing plate 10 as described above. Advantageously, the lateral edge 17 of the sealing plate 10 is close to the lateral edge 27 of the ferrule segment 20. The sealing plate is mounted on the first face 201 by the first fastening means, for example a first screw 31 and a first nut 61.

[0061] With reference to [Fig. 5], the sealing plate is arranged in the first position and can be reversibly locked in this position. In the latter case, the sealing plate is unlocked to allow sliding parallel to the upstream edge 26 of the ferrule segment 20. For example, the sealing plate can be unlocked by loosening the nut 61 by rotating it relative to the screw 31.

[0062] The sealing plate 10 is then slid towards the structural arm to cover the mechanical gap 52 at the upstream end of the ferrule segment. After this step, the sealing plate is in its second position. A portion of the sealing plate remains in surface contact with the first face 241 of the metal cladding. Another portion of the sealing plate is in surface contact with a first surface 501 of the structural arm 50 oriented in the same direction as the first surface 201 of the ferrule segment. Thus, the mechanical gap is covered over its entire width.

[0063] Preferably, the sealing plate extends beyond the mechanical clearance 52 on each side by a distance corresponding to approximately 5 times the width of the mechanical clearance.

[0064] In one embodiment, with reference to [Fig. 6], the structural arm comprises a rib 57 essentially parallel to the lateral edge 17 of the sealing plate. The sealing plate 10 is slid until it reaches the rib 17, which forms a stop for the second position.

[0065] Such a rib is for example formed by a fold in the sheet forming the structural arm 50. The structural arm may have such a fold on its first surface 501 in order to form a groove 58 for the fixing of a seal of the structural arm on an inner face 502 of the groove, opposite to the first face 501. In this case, the rib 57 can be used as a stop for the sealing plate, without adding additional elements to the arm or other elements of the groove.

[0066] When the sealing plate reaches the second position, as shown in [Fig. 7], the second fastening means 32 is inserted into the second hole 22 of the ferrule segment and the fastening hole 12 of the sealing plate 10. The second fastening means is tightened, for example by adding a washer 72 and a nut 62 to the screw 32, to secure the sealing plate in the second position. Preferably, the first fastening means 31 is also tightened to further ensure the immobility of the sealing plate.

[0067] The sealing plate thus ensures a fire seal between the inside and outside of the duct, allowing for example the protection of elements such as heat exchangers arranged in the duct of the turbomachine.

[0068] In the case where the ferrule segment has several sealing plates, for example to cover a mechanical clearance at the upstream edge and at the downstream edge, and / or a mechanical clearance on both lateral edges, the process is repeated for all the respective sealing plates.

[0069] For the assembly of a complete ferrule, the process is repeated for all ferrule segments.

[0070] To disassemble a ferrule segment with a sealing plate, the second fastening means 32 is first loosened and removed. The sealing plate 10 is then slid from the second position to the first position. If necessary, the sealing plate can be locked in the first position. The ferrule segment can then be removed from the turbomachine in a known manner.

Claims

Demands

1. Ferrule segment (20) adapted to delimit a portion of a turbomachine duct, characterized in that it comprises, on a first face (201, 241), a sealing plate (10) mounted movably to slide between a first position and a second position, said sealing plate (10) being adapted to be selectively fixed to the ferrule segment (20) in the second position in which the sealing plate is projecting from a lateral edge of the ferrule segment (20) to cover a junction between the ferrule segment and a structural arm (50) of the turbomachine.

2. Ferrule segment according to claim 1, wherein the sealing plate is arranged on a first face (241) of an end of the ferrule segment having a metal coating (24).

3. Ferrule segment according to any one of claims 1 and 2, wherein the sealing plate (10) is removable from the ferrule segment (20).

4. Ferrule segment according to any one of claims 1 to 3, wherein the sealing plate (10) has a fixing hole (12) and an oblong hole (11), the ferrule segment (20) having a first hole (21) and a first fixing means (31) adapted to pass through the first hole (21) and the oblong hole (11) of the sealing plate (10) so as to keep the sealing plate (10) movable in sliding relative to the ferrule segment (20), the ferrule segment (20) further having a second hole (22) and a second fixing means (32) adapted to pass through the second hole (22) and the fixing hole (12) of the sealing plate so as to fix the sealing plate in the second position.

5. Ferrule segment according to claim 4, wherein the first and / or second fastening means (31, 32) is a countersunk head screw and the first hole (21) and / or second hole (22) has a milling adapted to house the head of said countersunk head screw in a second face (202) opposite the first face (201) of the ferrule segment (20).

6. Ferrule segment according to any one of claims 1 to 5, wherein the sealing plate (10) is made of metal, preferably steel or titanium.

7. Aircraft turbomachine, comprising a shell forming at least partially an airflow channel, said shell comprising a plurality of segments (20) according to any one of claims 1 to 6, said segments being delimited by a plurality of structural arms (50) extending radially in the channel, each sealing plate (10) being arranged to cover a junction between a shell segment (20) and a respective structural arm (50).

8. Turbomachine according to claim 7, wherein at least one sealing plate (10) arranged on a shell segment (20) covers, in the second position, a surface having a width of at least ten times the width of a mechanical clearance (52) within the junction between a shell segment (20) and a respective structural arm (50).

9. A method for mounting a ferrule segment (20) in a turbomachine comprising a structural arm extending in a channel, said method comprising the following steps: • making available at least one ferrule segment (20) according to any one of claims 1 to 6, the sealing plate (10) being in the first position; • mounting the ferrule segment (20) in the turbomachine, a mechanical clearance being present between the ferrule segment and the structural arm (50); • moving the sealing plate (10) in a direction essentially parallel to an upstream or downstream edge 26 of the ferrule segment, so as to cover the junction between the ferrule segment (20) and the arm (50); and • fixing the sealing plate (10) in a fixed manner relative to the ferrule segment (20) in the second position.

10. Method according to claim 9, wherein, in the second position, the sealing plate (10) comes to rest against a rib (57) arranged on a first face (501) of the arm (50) opposite the vein and formed by a fold included in a sheet forming the arm (50), said fold forming a slot (58) on a second face (502) of the arm (50) oriented in the direction of the vein.

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