REPAIR SKIN FOR A BLOWER RECTIFIER PLATFORM AND ASSOCIATED REPAIR PROCESS

Abstract

The present invention relates to a repair skin (33) for at least partially covering a turbomachine stator platform (30). The invention also relates to a method for repairing a damaged stator platform (30) extending between two successive stator blades, comprising a step of bonding a repair skin (33) to the stator platform (30) so as to at least partially cover a flow face (32) of said stator platform (30) to ensure aerodynamic continuity of the flow. Figure for the abstract: Figure 3

Description

Title of the invention: REPAIR SKIN FOR A BLOWER RECTIFIER PLATFORM AND ASSOCIATED REPAIR METHOD

[0001] The present invention relates to a repair skin for a fan stator platform and to the associated repair method. The invention finds a particularly advantageous, but not exclusive, application in the field of aeronautics, with dual-flow turbomachinery.

[0002] In a manner known per se, a turbomachine comprises a fan casing surrounding a fan designed to compress the air entering the engine. Part of this air constitutes the primary flow circulating in a primary flow channel, and the other part of this air constitutes the secondary flow circulating in a secondary flow channel. The primary flow passes through a low-pressure compressor, a high-pressure compressor, then a combustion chamber, a high-pressure turbine, and finally a low-pressure turbine before being ejected. The secondary flow bypasses the hot section of the turbomachine.

[0003] A straightener is disposed downstream of the fan in the secondary flow channel. The straightener comprises a plurality of fixed vanes that straighten the airflow exiting the fan. These vanes are also each designated by the acronym OGV for "Outlet Guide Vane" according to Anglo-Saxon terminology. The straightener also includes arms that provide a connection between a hub of the straightener and an intermediate casing (VCI) ferrule located downstream of the fan casing.

[0004] Stiffener platforms, known as "OGV platforms," ​​extend between two consecutive blades to form a portion of the radially outer side of the secondary flow channel. These OGV platforms, generally made of a rigid plastic material, contribute to the aerodynamic performance of the secondary flow channel between the stator blades.

[0005] During flights, the engine is subjected to various weather conditions and ingestions, particularly of birds. This can lead to damage to engine inlet components, especially the OGV platforms.

[0006] Damage to one or more OGV platforms can lead to a decrease in engine performance that may last for several flight cycles before the damaged platforms are replaced.

[0007] The invention aims to effectively remedy this drawback by proposing an assembly for an aircraft engine comprising: - a damaged rectifier platform extending between two successive rectifier blades, said rectifier platform having an off-flow face intended to be turned towards a structural element on a side opposite a flow channel and a flow face forming at least a portion of a flow channel, - said assembly further comprising a repair skin glued onto the rectifier platform, so as to cover at least part of the flow face of said rectifier platform to ensure aerodynamic continuity of the flow vein.

[0008] The invention thus makes it possible, thanks to the repair skin, to reconstruct the flow path following damage to the straightener platform. The invention also makes it possible to increase the number of flight cycles before replacing the broken part while limiting the loss of aerodynamic performance. The invention also has the advantage of not interfering with the assembly of adjacent parts and is economically advantageous since the invention is inexpensive to implement.

[0009] According to one embodiment of the invention, the repair skin has a low thickness, in particular less than 5mm, and preferably less than 2mm.

[0010] According to one embodiment of the invention, the repair skin includes a chamfer made in at least one inlet edge of an airflow.

[0011] According to one embodiment of the invention, the rectifier platform has fixing holes intended to receive fixing elements for fixing the rectifier platform onto the structural element.

[0012] According to one embodiment of the invention, the straightener platform comprises pads extending from the off-grain face, said pads carrying shock absorbers intended to bear against the structural element.

[0013] According to one embodiment of the invention, the straightener platform includes stiffening ribs.

[0014] The invention also relates to a method for repairing a damaged rectifier platform extending between two successive rectifier blades, said rectifier platform having an off-flow face intended to be turned towards a structural element on a side opposite a flow duct and a duct face forming at least a portion of a flow duct, said method comprising a step of gluing a repair skin onto the rectifier platform, so as to at least partially cover the duct face of said rectifier platform to ensure aerodynamic continuity of the flow duct.

[0015] According to one embodiment of the invention, said method includes a preliminary cutting step of an outer contour of the repair skin so as to correspond to the dimensions of the straightener platform.

[0016] According to one embodiment of the invention, the cutting of the outer contour of the repair skin is carried out using a template having dimensions corresponding to the outer contour of the platform.

[0017] According to one embodiment of the invention, the repair skin is pre-cut to the dimensions of the straightener platform.

[0018] Advantageously, said method is implemented during an underwing inspection and repair phase of the aircraft.

[0019] The present invention will be better understood and other features and advantages will become apparent upon reading the following detailed description, which includes embodiments given by way of illustration with reference to the accompanying figures, presented by way of non-limiting examples, which may serve to complete the understanding of the present invention and the explanation of its implementation and, where appropriate, contribute to its definition, on which:

[0020] [Fig-1] The [Fig. 1] is a partial longitudinal cross-sectional view of an aircraft turbomachine;

[0021] [Fig.2] Fig.2 is a detailed perspective view illustrating the positioning of OGV platforms on an intermediate casing ferrule;

[0022] [Fig. 3] Fig. 3 is a perspective view of an OGV platform intended to be covered by a repair layer;

[0023] [Fig.4] Fig.4 is a perspective view of a rear face of a platform OGV intended to be covered by a repair skin;

[0024] [Fig. 5] Fig. 5 is an exploded perspective view of a repair skin according to the invention intended to cover a radially internal face of an OGV platform;

[0025] [Fig. 6] Fig. 6 is a perspective view showing the curvature of a platform OGV covered by a repair skin according to the invention.

[0026] It should be noted that, in the figures, structural and / or functional elements common to the different embodiments may have the same reference numerals. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0027] In the following description, the radially internal and radially external faces of the straightener platform and the repair skin are considered with respect to the X axis of the turbomachine.

[0028] Figure 1 shows a schematic partial longitudinal cross-sectional view of an aircraft turbomachine 10, here a turbofan engine with axis X. This turbomachine 10 comprises a fan casing 12 surrounding a fan 11 for compressing the air entering the engine. Part of this air constitutes the primary flow circulating in a primary flow channel 13, and the other part of this air constitutes the secondary flow circulating in a secondary flow channel. 14. The primary flow passes through a low-pressure compressor 15, a high-pressure compressor, then a combustion chamber, a high-pressure turbine, and finally a low-pressure turbine before being ejected. The high-pressure compressor, combustion chamber, high-pressure turbine, and low-pressure turbine are not shown in the figure to facilitate understanding of the invention.

[0029] A straightener 18, also designated by the acronym OGV for "Outlet Guide Vane" according to Anglo-Saxon terminology, extends downstream of the blower 11 in the secondary flow channel 14. The straightener 18 comprises a plurality of fixed vanes 17 allowing the straightening of the airflow at the outlet of the blower 11. The straightener 18 further comprises arms providing a mechanical connection between a hub 20 of the straightener 18 and an intermediate casing ferrule 28 (VCI) located downstream of the blower casing 12.

[0030] Rectifier platforms 30 visible in [Fig. 2] are fixed to a structural element, in this case the intermediate housing ferrule 28, which is generally annular in shape. Each rectifier platform 30 extends between two successive rectifier blades 17.

[0031] Each straightener platform 30 has an off-flow face 31 corresponding to a radially external face of the straightener platform 30. The off-flow face 31 is oriented towards the structural element, in this case the intermediate housing shell 28, on a side opposite the secondary flow channel 14. Each straightener platform 30 also has a flow face 32 corresponding to a radially internal face 32 of the straightener platform 30. The flow face 32 forms at least a portion of the secondary flow channel 14. A straightener platform 30 can extend along an angular sector of an annular shape. The flow face 32 of the straightener platform 30 has a concave shape, while the off-flow face 31 of the straightener platform 30 has a convex shape, as illustrated in [Fig. 6]. Alternatively, a rectifier platform 30 can extend along an angular sector of a truncated cone shape.In some cases, a rectifier platform 30 may also exhibit at least partially a planar shape.

[0032] As illustrated in Figures 3 and 4, the rectifier platform 30 has mounting holes 34 for receiving fasteners for fixing the rectifier platform 30 to the intermediate housing ferrule 28. The fasteners preferably consist of screws, intended to be screwed onto the intermediate housing ferrule 28.

[0033] The straightener platform 30 may include pads 40 extending from the off-grain face 31 (see [Fig. 4]). The pads 40 carry dampers 41 intended to come into support against the intermediate casing ferrule 28. The shock absorbers 41 are made of an elastic material, such as an elastomer or silicone.

[0034] The straightener platform 30 may also include stiffening ribs 42 made on its off-rib face 31.

[0035] A repair skin 33 shown in Figures 3, 5 and 6 is glued onto a damaged straightener platform 30, so as to cover at least part of the vein face 32 of said straightener platform 30 to ensure aerodynamic continuity of the secondary flow vein 14.

[0036] For this purpose, the repair skin 33 has a radially internal face 35 with a smooth configuration and a radially external face 36 provided with an adhesive layer so as to be able to be glued onto the vein face 32 of the straightener platform 30. The adhesive can be chosen from a neoprene glue, a cyanoacrylate glue, an epoxy glue or any other type of glue suitable for fixing a repair skin 33 onto the straightener platform 30 generally made of a rigid plastic material.

[0037] The repair skin 33 has an outer contour corresponding to that of the blower straightener platform 30. The outer contour of the repair skin 33 may correspond exactly to the outer contour of the platform. In this case, the repair skin 33 completely covers the vein face 32 of the straightener platform 30 to recreate a complete external surface of the straightener platform 30. Alternatively, the repair skin 33 has an outer contour circumscribed within the contour of the straightener platform 30.

[0038] The repair skin 33 advantageously has a low thickness, in particular less than 5 mm, and preferably less than 2 mm. The repair skin 33 can be made of a material selected from: a plastic material, a metallic material, or a composite material. The material selected is sufficiently strong to withstand the impacts that may result from the ingestion of debris and / or volatiles inside the engine.

[0039] According to certain embodiments, the repair skin has a chamfer 39 formed in at least one inlet edge of an airflow. The inlet edge of the airflow is the edge of the repair skin 33 that the airflow encounters first when it flows inside the secondary flow channel 14. Such a configuration improves the aerodynamics of the repair skin 33.

[0040] The invention also relates to a method for repairing a damaged rectifier platform 30 comprising a step of bonding a repair skin 33 onto the rectifier platform 30, so as to cover the vein face 32 of said rectifier platform 30 to ensure aerodynamic continuity of the secondary flow vein 14.

[0041] The method may include a preliminary step of cutting an outer contour of the repair skin 33 so as to correspond to the dimensions of the straightener platform 30. The outer contour of the repair skin 33 may correspond exactly to the outer contour of the straightener platform 30. Alternatively, the outer contour of the repair skin 33 may be circumscribed within the outer contour of the straightener platform 30.

[0042] The cutting of the outer contour of the repair skin 33 is carried out using a template having dimensions corresponding to the outer contour of the straightener platform 30.

[0043] Alternatively, the repair skin 33 is pre-cut to the dimensions of the straightener platform 30. In this case, the operator will only have to remove a protective film from the repair skin 33 before sticking it onto the vein face 32 of the straightener platform 30.

[0044] Alternatively, the repair skin 33 has dimensions corresponding only to the dimensions of the damaged area of ​​the rectifier platform 30.

[0045] Advantageously, the method according to the invention is implemented during an underwing inspection and repair phase of the aircraft. This underwing inspection and repair phase can take place between flights on the tarmac or within an airport facility. This inspection and repair phase is short (on the order of a few hours at most) as opposed to repair phases carried out in a maintenance hangar that can last several days.

[0046] In the embodiment shown in Figures 1 to 6, the straightener platforms 30 are arranged radially outside the secondary flow channel 14. In the case where a straightener platform 30 is arranged radially inside the secondary flow channel 14, the off-channel face of the straightener platform 30 corresponds to a radially internal face and the channel face of the straightener platform 30 corresponds to a radially external face of the straightener platform 30. A repair skin 33 can then be bonded to a radially external damaged channel face of the straightener platform 30.

[0047] Alternatively, the rectifier platform 30 can be fixed on a structural element other than the intermediate housing ferrule 28.

[0048] Of course, the different features, variants and / or embodiments of the present invention can be combined with each other in various ways insofar as they are not incompatible or mutually exclusive.

[0049] Furthermore, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms, and other variants that a person skilled in the art may consider within the framework of the present invention and in particular all combinations of the different modes of operation described above, which can be taken separately or in association.

Claims

Demands

1. Assembly for an aircraft engine comprising: - a damaged stator platform (30) extending between two successive stator blades (17), said stator platform (30) having an off-flow face (31) intended to be turned towards a structural element (28) on a side opposite a flow duct (14) and a flow face (32) forming at least a portion of the flow duct (14), characterized in that said assembly further comprises a repair skin (33) bonded to the stator platform (30), so as to cover at least part of the flow face (32) of said stator platform (30) to ensure aerodynamic continuity of the flow duct (14).

2. Assembly according to claim 1, characterized in that the repair skin (33) has a low thickness, in particular less than 5mm, and preferably less than 2mm.

3. Assembly according to claim 1 or 2, characterized in that the repair skin (33) has a chamfer (39) made in at least one inlet edge of an airflow.

4. Assembly according to any one of claims 1 to 3, characterized in that the rectifier platform (30) has fixing holes (34) intended to receive fixing members for fixing the rectifier platform (30) onto the structural element (28).

5. Assembly according to any one of claims 1 to 4, characterized in that the straightener platform (30) comprises pads (40) extending from the off-grain face (31), said pads (40) carrying dampers (41) intended to bear against the structural element (28).

6. Assembly according to any one of claims 1 to 5, characterized in that the straightener platform (30) comprises stiffening ribs (42).

7. Method of repairing a damaged rectifier platform (30) extending between two successive rectifier blades (17), said rectifier platform (30) having an off-flow face (31) intended to be turned towards a structural element (28) on a side opposite a flow vein (14) and a flow face (32) forming at least a portion of the flow vein (14), characterized in that said process includes a step of bonding a repair skin (33) onto the straightener platform (30), so as to cover at least partially the vein face (32) of said straightener platform (30) to ensure aerodynamic continuity of the flow vein (14).

8. Method according to claim 7, characterized in that it comprises a preliminary cutting step of an outer contour of the repair skin (33) so as to correspond to dimensions of the straightener platform (30).

9. Method according to claim 8, characterized in that the cutting of the outer contour of the repair skin (33) is carried out by means of a template having dimensions corresponding to the outer contour of the platform.

10. Method according to claim 8, characterized in that the repair skin (33) is pre-cut to dimensions of the straightener platform (30).

11. A method according to any one of claims 7 to 10, characterized in that it is implemented during an underwing inspection and repair phase of the aircraft.

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