Endoscope plug mounting method

Abstract

This document relates to a turbomachine assembly (100) comprising a mounting device (300) for an endoscope plug (S5) in an annular row of stator blades of the turbomachine with a longitudinal axis, the annular row of stator blades having an orifice (182) for receiving the endoscope plug, the mounting device (300) comprising keying means (301) including a sealing portion (302) configured to seal at least a portion of said orifice (182), and a retractable portion (304) configured to be moved in a first circumferential direction (306) under the effect of a radial displacement of the endoscope plug (S5) in the direction of the longitudinal axis (X), said retractable portion (304) being connected to the sealing portion (302) and causing the movement of the sealing portion (302) in the first circumferential direction (306) to free the orifice (182). Figure to be published with the abbreviation: [Fig. 5]

Description

Title of the invention: Means for mounting endoscope caps Technical field of the invention

[0001] The present invention belongs to the field of turbomachine mounting. It relates more particularly to a device for mounting an endoscope in a row of blades of a turbomachine. State of the prior art

[0002] Monitoring the wear and use of a turbomachine requires detailed knowledge of the conditions during the various flights, both in terms of environmental data, in particular the meteorological environment, and in terms of engine operating data. For this purpose, endoscope plugs are provided in annular rows of blades of the turbomachine.

[0003] An assembly for an aircraft turbomachine is shown in [fig. 1], in which the upstream (AM) and downstream (AV) of the structure along an engine axis, i.e. the longitudinal axis X below, are located respectively to the left and right of [fig.l].

[0004] The central portion of the turbomachine 10, forming the gas turbine engine 12, is mounted within an engine nacelle assembly 14, as is typical of an aircraft designed for subsonic operation, such as a turboprop or a turbofan engine. The nacelle assembly 14 generally comprises an engine nacelle 16 and a fan nacelle 18 surrounding a fan 20 located axially upstream of the engine 12.

[0005] The engine 12 comprises, axially in the downstream part, at least one turbine which may be a low pressure turbine and at least one turbine which may be a high pressure turbine, and again in the downstream part, an exhaust casing 22 comprising an internal annular shell 22a and an external annular shell 22b delimiting between them a downstream part of the primary annular vein 24 in which the combustion gases from the combustion chamber of the engine 12 circulate. The internal annular shell 22a is connected, at its downstream end, to the ejection cone 1, which may comprise an upstream part 1a, of substantially cylindrical shape, and a downstream part 1b of conical shape.

[0006] Compressors and turbines are formed by an intercalated succession of annular rows of stator blades and annular rows of moving blades. To monitor the condition of compressors and turbines, in particular the condition of the stator blades, endoscope plugs are generally arranged in holes provided in the casing surrounding the annular rows of stator blades.

[0007] When assembling the compressor or maintaining it, reversing the plugs endoscope in their respective holes can be committed.

[0008] There is a need to improve the mounting of endoscope caps in compressors by avoiding confusion between the holes of the endoscope caps. Summary of the invention

[0009] To this end, the present disclosure proposes an assembly for a turbomachine comprising a device for mounting an endoscope plug in an annular row of stator blades of a turbomachine with a longitudinal axis, the annular row of stator blades having an orifice provided for receiving the endoscope plug,

[0010] the mounting device comprises keying means comprising a sealing portion configured to seal at least a portion of said orifice, and a retractable portion configured to be moved in a first circumferential direction under the effect of a radial movement of the endoscope cap in the direction of the longitudinal axis, said retractable portion being connected to the sealing portion and causing the sealing portion to move in the first circumferential direction to release the orifice.

[0011] Thus, the mounting device makes it possible to ensure the mounting of only the endoscope cap capable of moving the keying means to release the orifice receiving the endoscope cap. The mounting device therefore makes it possible to limit confusion between endoscope caps during the mounting or maintenance of the turbomachine.

[0012] The endoscope plug may be mounted at a compressor of the turbomachine, in particular a high-pressure compressor. The compressor may be formed by a succession of stages where each stage comprises an annular row of stator blades adjacent to an annular row of moving blades. In particular, the endoscope plug may be mounted in a casing surrounding the compressor and carrying the annular row of stator blades.

[0013] The retractable portion may include a protrusion extending in a second circumferential direction opposite the first circumferential direction. The protrusion may be configured to be moved in the first circumferential direction when it contacts a skirt of the endoscope cap.

[0014] The endoscope cap may have a portion insertable into the orifice, the skirt being arranged above the portion insertable into the orifice.

[0015] The skirt of the endoscope cap may have a diameter greater than the diameter of the orifice provided to receive said endoscope cap.

[0016] The keying means may comprise a tab carrying the retractable portion and the closure portion. The tab may be deformable. The tab may be metallic.

[0017] The mounting device may comprise fastening means configured to fasten said device to a ferrule surrounding the annular row of stator vanes at the orifice.

[0018] The assembly may comprise a succession of a first annular row of stator blades and a second annular row of stator blades separated by an annular row of moving blades.

[0019] The assembly may further comprise a first endoscope plug provided with a skirt intended to be mounted in the first annular row of stator vanes by the mounting device and a second endoscope plug intended to be mounted in the second annular row of stator vanes.

[0020] The second endoscope cap may be skirtless. Alternatively, the second endoscope cap may include a skirt having a diameter smaller than the diameter of the skirt of the first endoscope cap.

[0021] The present disclosure also relates to a turbomachine comprising an assembly as mentioned above.

[0022] The present disclosure also relates to a method of mounting an endoscope cap in an assembly as described above, comprising the following steps:

[0023] - fix the mounting device at the hole,

[0024] - inserting said endoscope plug into the orifice by radially moving the plug endoscope towards the longitudinal axis,

[0025] - exchange said endoscope cap with another endoscope cap when it is not can be introduced into the hole during the previous step. Brief description of the figures

[0026] [fig. 1] [fig.l], already described, represents a schematic section of the profile of a turbomachine for aircraft.

[0027] [fig.2] [fig.2] represents a schematic section in profile of an example of a tur bomachine.

[0028] [fig.3] [fig.3] represents a part of the schematic section of the profile of com turbomachine presser of [fig.2] equipped with endoscope plugs.

[0029] [fig.4] [fig.4] represents an enlarged part of the schematic section of the com presser of [fig.3].

[0030] [fig.5] [fig.5] represents a device for mounting an endoscope cap in the compressor of figures 3 and 4, front view.

[0031] [fig.6] [fig.6] represents the mounting device of an endoscope cap of the [fig.5] side view.

[0032] [fig.7] [fig.7] shows a method of mounting an endoscope cap in the compressor of figures 3 and 4. Detailed description of the invention

[0033] With reference to Figures 2 to 4, the turbomachine 100 comprises a fan 111, a low-pressure compressor 112, a high-pressure compressor 113, a combustion chamber 114, a high-pressure turbine 115 and a low-pressure turbine 116. The compressors 112 and 113, the combustion chamber 114 and the turbines 115 and 116 are arranged in a primary vein 170 extending between a first radially internal surface 117, and a first radially external surface 118 extending radially around the radially internal surface 117, a second radially internal surface 110 also defining with a second radially external surface 119 a secondary vein 190.

[0034] The high pressure compressor HP 113 is made up of stages of successive rotating parts around a longitudinal axis X, where each stage of rotating parts comprises an annular row of stator blades 124 and an annular row of moving blades, not shown in the figures.

[0035] The annular rows of stator blades 124 may comprise stator blades with a variable pitch angle, thus forming rectifier stages. In this case, each annular row of stator blades 124 is associated with a means 126 for controlling the pitch angle of the stator blades.

[0036] Alternatively, the stator vanes may be stator vanes with a fixed pitch angle, thus forming a stage of distributors.

[0037] The turbomachine 100 further comprises endoscopy holes 180 arranged in the casing of the HP compressor 113 and which are provided to receive endoscope plugs S1 to S6 and allowing access, for example visually using an endoscope, to the blades of the high-pressure compressor 113 to check their condition during ground maintenance operations.

[0038] Each endoscopy hole 180 is preferably located at each annular row of stator vanes 124.

[0039] These endoscopy holes 180 are located on a high-pressure compressor casing 113 of the turbomachine, i.e. the first radially external surface 118, mostly on one side thereof, and sporadically on the other side for reasons of practical access and space requirements.

[0040] Each endoscope cap S1-S6 is an optical instrument and comprises a main body including a portion 202 abutting against the high pressure compressor housing 113 and closing the endoscopy hole 180.

[0041] The annular rows of stator blades 124 are mounted on shrouds 122 and 123 connected to each other by connecting flanges. An annular thermal protection 120 is arranged around the shrouds 122, 123 comprising the annular rows sta- toric 124.

[0042] The ferrules 122 and 123 each comprise an orifice 182 and 184 provided to receive an endoscope cap S5 and S6, respectively.

[0043] The associated orifices 182 and 184 are through-holes to allow access to the aerodynamic vein 170 in order to allow its inspection through the endoscopy orifices 182 and 184 closed by the endoscope plugs S5-S6.

[0044] When mounting the endoscope caps S5-S6 in their respective holes 182 and 184, there is a risk of confusion in mounting the endoscope cap S5 in hole 184 and / or the endoscope cap S6 in hole 182.

[0045] To avoid these mounting errors and to simplify it, a mounting device 300, shown in Figures 5 and 6, is arranged at the orifice 182 receiving the endoscope cap S5. The mounting device 300 allows the mounting of the endoscope S5 in the orifice 182 only.

[0046] Alternatively, the mounting device 300 may be configured to allow mounting of the endoscope cap S6 in the port 184 only.

[0047] The mounting device 300 comprises keying means 301 in the form of a deformable tab.

[0048] The foolproofing means 301 comprise a closure part 302 capable of closing the orifice 182 and a retractable part 304 connected to the closure part 302.

[0049] The retractable portion 304 is movable in a first circumferential direction 306 and thus causes the closure portion 302 to move in the first circumferential direction 306, thereby freeing the orifice 182. The retractable portion 304 is movable in the first circumferential direction 306 when the endoscope cap S5 is moved in the radial direction toward the longitudinal axis X. This arrangement makes it possible to mount the endoscope cap S5 in the orifice 182 in a simple manner.

[0050] The endoscope cap S5 is provided with a skirt 204 arranged above an insertable portion 205 of the endoscope cap S5 in the corresponding orifice 182. The insertable portion 205 may have a cylindrical shape.

[0051] The endoscope cap S6 is preferably without a skirt. Alternatively, the endoscope cap S6 comprises a skirt having a diameter smaller than the diameter of the skirt of the endoscope cap S5.

[0052] Preferably, the skirt 204 of the endoscope cap S5 has a diameter greater than the diameter of the insertable portion 205.

[0053] The retractable portion 304 of the endoscope cap S5 has a protrusion extending in a second circumferential direction opposite the first circumferential direction. The protrusion of the retractable portion is preferably sized in the second circumferential direction such that it causes the total or partial release of the orifice 182 when the skirt 204 is in contact with said protuberance.

[0054] The mounting device 300 may be metallic or made of any other deformable material. Preferably, the radial displacement of the endoscope cap S5 causes a deformation of the tab 301 in the elastic domain.

[0055] The mounting device 300 further comprises means 308 for fixing the mounting device 300 to the ferrule 122, in particular to a flange of said ferrule 122. The fixing means 308 are advantageously in the form of a sheet metal fixed to the flange of the ferrule 122 by any fixing means, for example screws and nuts. For example, these screws and nuts may be the fixing means connecting the flange of the ferrule 122 to a flange of the ferrule 123 carrying the orifice 184 provided to receive the endoscope cap S6.

[0056] Furthermore, the ferrule 123 is fixed to another ferrule 125 connected to the high pressure compressor casing 113.

[0057] [fig.7] represents a method 400 of mounting an endoscope plug S1-S6 in an orifice giving access to a stage of rotating parts of the HP compressor 113. For example, the orifice can be the orifice 182 of the turbomachine 100.

[0058] The method 400 comprises a step 402 of fixing the mounting device 300 at the orifice 182.

[0059] The method 400 then comprises a step 404 of inserting an endoscope plug S1-S6 into the orifice 182 by radially moving the endoscope plug S1-S6 towards the longitudinal axis. This step causes the retractable part 304 to move and therefore the sealing part 302 if the endoscope plug introduced is indeed the endoscope plug S5 includes the skirt 204.

[0060] The method 400 comprises a step 406 of exchanging said endoscope plug S1-S6 with another endoscope plug when it cannot be introduced into the orifice during step 402.

Claims

Claims

1. Assembly for a turbomachine (100) comprising a mounting device (300) for an endoscope plug (S1-S6) in an annular row of stator vanes (124) of the turbomachine (100) of longitudinal axis (X), the annular row of stator vanes (124) having an orifice (182, 184) provided to receive the endoscope plug (S1-S6), the mounting device (300) comprises keying means (301) comprising a closing portion (302) configured to close at least a portion of said orifice (182, 184), and a retractable portion (304) configured to be moved in a first circumferential direction (306) under the effect of a radial movement of the endoscope plug (S5) in the direction of the longitudinal axis (X), said retractable portion (304) being connected to the closure portion (302) and causing the closure portion (302) to move in the first circumferential direction (306) to release the orifice (182,184).

2. An assembly according to claim 1, wherein the retractable portion (304) comprises a protrusion extending in a second circumferential direction opposite to the first circumferential direction (306), said protrusion being configured to be moved in the first circumferential direction (306) when it comes into contact with a skirt (204) of the endoscope cap (S5).

3. Assembly according to claim 1 or 2, in which the keying means (301) comprise a tab carrying the retractable part (304) and the closing part (302).

4. An assembly according to one of claims 1 to 3, wherein the mounting device (300) comprises fixing means configured to fix said device to a ferrule (122) surrounding the annular row of stator blades (124) at the orifice (182,184).

5. An assembly according to any one of claims 1 to 4, comprising a succession of a first annular row of stator vanes (124) and a second annular row of stator vanes (124) separated by an annular row of moving vanes, the assembly further comprising a first endoscope plug (S5) provided with a skirt (204) intended to be mounted in the first annular row of stator vanes (124) by the mounting device (300) and a second endoscope plug (S6) intended to be mounted in the second annular row of stator blades (124).

6. An assembly according to claim 5, wherein the second endoscope cap (S6) is skirtless.

7. Turbomachine (100) comprising an assembly according to one of the preceding claims.

8. Method (400) for mounting an endoscope cap (S1-S5) in an assembly according to one of claims 1 to 6, comprising: - fixing (402) the mounting device (300) at the orifice (182), - inserting (404) said endoscope cap (S1-S6) into the orifice (182) by radially moving the endoscope cap (S1-S6) towards the longitudinal axis (X), - exchanging (406) said endoscope cap (S1-S6) with another endoscope cap (S1-S6) when it cannot be introduced into the orifice (182) during the previous step (402).

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