Operating assembly and method for operating aircraft propulsion unit

Abstract

The invention relates to an operating assembly (31) of a propulsion assembly comprising a nacelle and an aircraft turbofan engine, characterized in that the operating assembly comprises: an operating jacket (35) covering at least half of the circumference of an outer wall (37) of an air intake duct (33) of the nacelle when the propulsion assembly is mounted on the operating assembly; at least two connections (43) for attaching a sling for connection to a lifting system (47) located outside the operating assembly (31). The invention also relates to a method for operating a propulsion assembly.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 201980055871.4, application date August 30, 2019, priority date August 31, 2018, and invention name “Operation components and methods for operating aircraft propulsion units”. Technical Field

[0002] The invention relates to an assembly for operating an aircraft propulsion unit and to a method for operating such an aircraft propulsion unit. Background Art

[0003] Multi-engine aircraft are driven by a plurality of propulsion units, each of which comprises a turbojet engine housed in a nacelle.

[0004] like Figure 1 As shown, the propulsion unit 1 comprises a nacelle 3 and a turbojet 5, for example a twin-flow type turbojet, capable of generating, via the blades of a rotating fan, a hot air flow (also called a mainstream) and a cold air flow (also called a secondary air flow), which circulates outside the turbojet through an annular channel 7 (also called annular channel) formed between two concentric walls of the nacelle. The mainstream and the secondary flow are ejected from the turbojet at the rear of the nacelle.

[0005] The nacelle generally has a tubular structure comprising an upstream section or air inlet 9 upstream of the turbojet engine, an intermediate section 11 for surrounding the fan of the turbojet engine, a downstream section 13 for surrounding the combustion chamber of the turbojet engine, this downstream section 13 carrying thrust reversal means and being able to be terminated by a nozzle located downstream of the turbojet engine.

[0006] In order to carry out maintenance operations on the nacelle, it is desirable to be able to manipulate the air intake of the nacelle independently of the middle and downstream sections of the nacelle.

[0007] Reference Figure 2 , which shows an embodiment of the prior art allowing manipulation of the air intake duct.

[0008] The prior art operating assembly 15 comprises two suspension cables 17, the lower ends of which are connected and fastened to the outer wall 19 of the air intake duct 9 of the nacelle, in contact with the external airflow flowing around the nacelle when the nacelle is in operation.

[0009] For this purpose, the nacelle comprises two or more fastening points 21 at its outer wall 19, forming suspension points, on which fittings supporting the suspension cables 17 are mounted.

[0010] When the sling 17 is mounted on the sling point 21 of the air intake 9, the operator can, for example, Figure 3 It is shown that the air intake duct is manipulated by tilting the air intake duct vertically so that the air intake duct can be placed on the ground in this vertical position.

[0011] A recurring problem for aircraft manufacturers is to reduce the aerodynamic disturbances of the cabin. To this end, cabin manufacturers seek to make certain surfaces of the cabin, in particular the outer walls of the cabin, smooth.

[0012] This object can be achieved in part by providing a nacelle comprising an air intake of a so-called laminar type, that is to say an air intake without aerodynamic folds, that is to say in particular without points for fastening accessories on which the slings of the operating assemblies of the prior art are intended to be mounted.

[0013] Removing the fastening points from the outer wall of the air intake of the nacelle makes it incompatible to use such an operating assembly of the prior art on a laminar nacelle. Summary of the invention

[0014] The aim of the present invention is to solve the above-mentioned drawbacks by proposing an assembly for operating the air intake of a cabin, in particular of the type that does not comprise attachment points at its outer wall.

[0015] To this end, the invention relates to an assembly for operating a propulsion unit comprising a nacelle and an aircraft turbojet engine, said operating assembly being notable in that it comprises:

[0016] an operating cowl which covers at least half of the circumference of the outer wall of the air intake of the nacelle when the propulsion unit is mounted on the operating assembly,

[0017] - At least two sling fastening connections for connection to a lifting system external to the handling assembly.

[0018] Thus, by providing an operating assembly comprising an operating housing designed to receive a sling fastening connection, the operating assembly may be used in particular on nacelles whose air inlets are laminar, that is to say do not comprise prior art accessory fastening points for mounting slings.

[0019] Optional features of the operating assembly according to the invention:

[0020] - the operating housing further comprises at least two pockets for receiving the at least two sling fastening connections, designed to hold the at least two sling fastening connections in position on the operating housing;

[0021] -The sling fastening connection part includes:

[0022] - a plate shaped to be inserted into the receiving pocket, and

[0023] - A sling fastening fitting, fixed to said plate, designed to receive a sling.

[0024] - pockets for receiving said at least two sling fastening connections are located on either side of the longitudinal plane of the operating assembly;

[0025] - a pocket for receiving said at least two fastening connections comprising means for closing said receiving pocket on the operating housing;

[0026] - the means for closing the receiving pocket on the operating housing is a Velcro Type self-tightening belt or zipper;

[0027] - the operating cowl comprises a transverse extension shaped so as to at least partially cover the circumference of the downstream edge of the air inlet duct of the nacelle when the propulsion unit is mounted on the operating assembly;

[0028] - According to one embodiment, the operating assembly comprises an inflatable flexible element which, when inflated, comes into contact at least with the inner wall of the air inlet of the nacelle when the propulsion unit is mounted on the operating assembly;

[0029] - when the inflatable flexible element is inflated and when the propulsion unit is mounted on the operating assembly, the inflatable flexible element occupies the entire internal space defined by the inner wall of the air intake duct of the nacelle;

[0030] - according to one embodiment, the inflatable flexible element comprises an upstream protrusion which, when said inflatable flexible element is inflated and when the propulsion unit is mounted on said operating assembly, comes into contact with the leading edge of the air inlet of the nacelle;

[0031] - the operating assembly comprises a main fastening strap, a first end of which is attached to the expandable flexible element and a second end of which is attached to the operating housing;

[0032] - the operating assembly comprises a circumferential main band positioned on a flange for fastening the air intake of the nacelle upstream of the fan casing of the turbojet engine;

[0033] The operating assembly comprises an additional fastening strap, a first end of which is attached to the circumferential main strap and a second end of which is attached to the operating housing.

[0034] The invention also relates to a method for operating a propulsion unit, the propulsion unit comprising:

[0035] - the cabin including the air intake, and

[0036] - an aircraft turbojet engine comprising a fan casing to which the air inlet of the nacelle is attached,

[0037] The operating method is characterized in that it comprises the following consecutive steps, which are intended to perform:

[0038] - covering at least half of the circumference of the outer wall of the air intake duct of the nacelle with an operating cowl;

[0039] - Positioning the sling fastening connection on the operating housing;

[0040] - a lifting system connecting the sling fastening connection to the outside of the operating assembly via a sling;

[0041] - Disassembling the air inlet from the fan casing of the turbojet engine.

[0042] In some embodiments, during the step aimed at positioning the sling fastening connection on the operating housing, the sling fastening connection is positioned within a pocket for receiving the operating housing.

[0043] In some embodiments, the operating method includes a first additional step before the step of covering at least half of the circumference of the outer wall of the air inlet of the cabin with an operating cover, the first additional step being intended to expand an inflatable flexible element of the operating assembly within an internal space defined by an inner wall of the air inlet of the cabin until the flexible element is in contact with at least the inner wall of the air inlet of the cabin.

[0044] In some embodiments, the operating method comprises, after the step of detaching the air inlet from the fan casing of the turbojet engine, a second additional step aimed at securing the operating assembly by attaching a first end of the main fastening strap to the expandable flexible element and attaching a second end of the main fastening strap to the operating cover.

[0045] According to one embodiment of the operating method according to the invention, the operating method comprises, before the step of detaching the air inlet from the fan case of the turbojet engine, a third additional step aimed at mounting a circumferential main belt on the fastening flange of the air inlet of the nacelle upstream of the fan case of the turbojet engine and aimed at attaching said main belt to the inflatable flexible element of the operating cowl by means of an additional fastening belt. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Other features and advantages of the present invention will become apparent upon reading the following detailed description, for the understanding of which reference should be made to the accompanying drawings, in which:

[0047] Figure 1 is a longitudinal cross-sectional view of a prior art propulsion unit;

[0048] Figure 2 and Figure 3 The operating components of the prior art supporting the air inlet of a turbojet engine nacelle are shown;

[0049] Figure 4 and Figure 5 Represents a perspective view of an operating assembly obtained according to a first embodiment of the invention, which supports an air inlet of a nacelle of a turbojet engine of an aircraft;

[0050] Figure 6 yes Figure 5 A main detailed view of area VI;

[0051] Figure 7 is a perspective view of an operating assembly for supporting an air inlet duct of a nacelle of a turbojet engine of an aircraft obtained according to a second embodiment of the present invention;

[0052] Figures 8 to 10 It shows the disassembly sequence of an air intake duct operated by an operating assembly obtained according to a second embodiment of the invention. DETAILED DESCRIPTION

[0053] In the description and claims, the terms "upstream" and "downstream" are to be understood relative to the circulation of the air flow inside the propulsion unit formed by the nacelle and the turbojet engine, that is to say with reference to Figure 1 From left to right.

[0054] Similarly, the terms "inner" or "inner" and "outer" or "external" will be used in a non-limiting manner with reference to radial distances relative to the longitudinal axis of the propulsion unit, the term "inner" or "inner" defining a region radially closer to the longitudinal axis of the nacelle, as opposed to the term "outer" or "external".

[0055] In addition, in the description and the claims, in order to clarify the description and the claims, the terms "longitudinal", "vertical" and "lateral" will be used without restriction with reference to the direct trihedrons L, V, T shown in the accompanying drawings, and the longitudinal axis L of the direct trihedrons L, V, T is parallel to the longitudinal axis of the operating component, and when the propulsion unit is supported by the operating component, the longitudinal axis of the operating component corresponds to the longitudinal axis of the propulsion unit.

[0056] Furthermore, in all the drawings, the same or similar reference numerals denote the same or similar components or component groups.

[0057] Reference Figure 4 and Figure 5 , which shows in a perspective view an operating assembly 31 obtained according to a first embodiment of the invention, which supports an air inlet 33 of a turbojet engine nacelle, Figure 4 and Figure 5 , respectively, the operating components are shown in an open position and in a closed position.

[0058] The operating assembly 31 comprises an operating cover 35 designed to support the turbojet nacelle air intake. For this purpose, the operating cover 35 can be obtained, for example, from any textile technical fabric, such as Available as nonwoven technical fabrics or as reinforced PVC.

[0059] The operating cover 35 covers the outer wall 37 of the air inlet duct 33. In the first embodiment of the operating assembly 31, the operating cover 35 preferably covers the entire circumference of the outer wall 37 of the air inlet duct when the operating assembly is in the closed position. However, it is conceivable to design the size of the operating cover 31 so that when the operating assembly is in the closed position, it only covers half of the circumference of the outer wall 37 of the air inlet duct.

[0060] Thanks to the closing means, for example when the treatment assembly supports the air intake, the closing means is positioned at twelve o'clock, thus achieving operation of the housing 35. Such closing means can be obtained, for example, by a self-tightening band 38 of the Velcro type.

[0061] According to one embodiment, the operating cowl 31 comprises a transverse extension 39 shaped so as to cover all or part of the circumference of the downstream edge 41 of the air inlet 33 of the nacelle.

[0062] The operating assembly 31 also includes two connecting parts 43 ( Figure 4 and 5 The sling 45 is intended to be connected to a lifting system 47 outside the operating assembly 31, which allows the operating assembly supporting the air intake of the nacelle to be manipulated. For this purpose, the operating housing 35 comprises two pockets 49 for receiving the sling fastening connections. The pockets 49 for receiving the sling fastening connections 43 are preferably located on either side of the longitudinal plane (L, V) of the operating assembly. The receiving pockets 49 are designed to keep the sling fastening connections 43 in position on the operating housing 35.

[0063] Reference Figure 6 , which is Figure 5 VI of FIG. 1 and shows a receiving pocket 49 in which the sling fastening connection 43 is inserted.

[0064] According to one embodiment, the sling fastening connection 43 comprises a plate 51 and a fitting 53 fixed to the plate 51, to which the sling 45 is fastened. The plate 51 is shaped to be insertable into the receiving pocket 49. The receiving pocket 49 has a rectangular overall shape extending along a longitudinal axis L defined by a right trihedron L, V, T shown in the figures.

[0065] The receiving pocket 49 has an opening 55 which receives the fitting 53 of the sling fastening connection 43. The receiving pocket 49 is also equipped with closing means allowing it to be closed on the operating housing 35, which can be obtained by means of a self-tightening strip of the Velcro type or a zipper.

[0066] Reference Figure 7, which shows in a perspective view an operating assembly 31 obtained according to a second embodiment of the invention, which supports an air inlet 33 of a turbojet engine nacelle.

[0067] According to this second embodiment, the operating assembly 31 also comprises an expandable flexible element 57 , which may be obtained, for example, from a plastic material such as PVC.

[0068] The inflatable flexible element 57 comprises a central bag 59 in a generally cylindrical shape. When the propulsion unit is mounted on said operating assembly, the inflatable flexible element 57, when inflated, comes into contact with the inner wall of the air inlet 33 of the nacelle, the inner wall of the air inlet being defined by the wall in contact with the airflow sucked by the propulsion unit when the propulsion unit is in operation. When the inflatable flexible element 57 is inflated, it occupies the entire internal space defined by the inner wall of the air inlet of the nacelle when the propulsion unit is mounted on the operating assembly 31.

[0069] According to a variant, the inflatable flexible element 57 comprises an upstream protuberance 61 or upstream coil which may adopt a substantially toroidal shape. When inflated, the upstream protuberance 61 comes into contact with the leading edge of the air inlet 33 of the nacelle when the propulsion unit is mounted on the operating assembly 31 .

[0070] The upstream protrusion 61 may be an integral part of the expandable flexible element 57 , that is, the central bladder 59 is extended by the upstream protrusion 61 at its upstream portion.

[0071] Alternatively, the upstream protuberance 61 may be associated with the central capsule 59. In this case, the expandable flexible element 57 comprises two independent subassemblies formed by the central capsule 59 on the one hand and by the upstream protuberance 59 on the other hand.

[0072] The presence of such an upstream projection 61 defines a stop at the leading edge of the air inlet duct 33 when the operating assembly 31 supports the latter.

[0073] This allows protecting the air intakes of the nacelle from possible impacts that may occur during its maneuvers.

[0074] According to one embodiment of the operating assembly 31 obtained according to this second embodiment, the operating assembly may comprise a plurality of main fastening straps 65 distributed on the periphery of the operating cover 35. Each fastening strap 65 comprises a first end 67 attached to the inflatable flexible element 57 and a second end 69 attached to the operating cover 35. 35. For this purpose, the upstream protrusion 61 and the central bag 59 comprise a plurality of anchoring points for the main fastening straps. Once in place, the main fastening straps ensure that the operating cover is held on the inflatable flexible element. Thus, the fastening straps allow the operating cover to be tensioned around the air inlet.

[0075] Reference now Figures 8 to 10Describing the operating method implemented by the operating assembly 31 according to the second embodiment of the present invention, these figures show the disassembly sequence of the air intake duct 33.

[0076] exist Figures 8 to 10 In the example shown, one attempts to manipulate the nacelle's air intake 33. For better visibility, the middle and downstream sections of the nacelle are hidden from the figure. The nacelle's air intake 33 is mounted on the fan casing of a turbojet engine 71 via a circumferential downstream fastening flange 73.

[0077] The inflatable flexible element 57 of the operating assembly 31 is inflated in the internal space defined by the inner wall of the air intake of the cabin. Once inflated, the inflatable flexible element 57 contacts the inner wall of the air intake of the cabin. If the inflatable element includes an upstream protrusion, the upstream protrusion is also inflated at this stage.

[0078] The outer wall 37 of the air intake duct 33 of the nacelle is then covered thanks to the operating cowl 35. As previously indicated, at least half of the circumference of the outer wall of the air intake duct is covered by the operating cowl 35.

[0079] The fan cowls (not shown) of the nacelle, which cowls surround the fan casing of the turbojet engine, are then opened or removed.

[0080] At this stage, it is possible to optionally mount a circumferential main belt 75 on a fastening flange 73 of the air inlet of the nacelle on the fan case of the turbojet engine 71 and then attach the main belt 75 to the operating cowl 35 by means of additional fastening belts 77 .

[0081] The sling fastening connection 43 is then positioned in a pocket 49 for receiving these connections, which are part of the operating housing 35. When the fastening connection 43 is positioned in the receiving pocket 49, the pocket 49 is closed due to the closing device and the sling fastening connection 43 is connected to the lifting system 47 via the sling 45.

[0082] When the air inlet 33 is connected to the lifting system 47, the air inlet 33 is separated from the fan casing of the turbojet engine 71 ( Fig. 9 ).

[0083] The operating assembly is fixed thanks to the main fastening strap 65. For this purpose, a first end 67 of the main fastening strap is attached to the expandable flexible element 57 and a second end 69 of the main fastening strap is attached to the operating housing 35.

[0084] According to one embodiment, the main fastening strap 65 connects the operating housing 35 on the one hand to the upstream protuberance of the inflatable flexible element 57 and on the other hand to the central bag 59 of the inflatable flexible element 57 at its downstream edge 79 .

[0085] Of course, the present invention is not limited to the only embodiments of the operating assembly and the operating method described above by way of exemplary examples, but on the contrary, the present invention includes all variants and combinations thereof involving technical equivalents of the device, if these variants and combinations thereof fall within the scope of the present invention.

Claims

1. An operating assembly (31) for operating a propulsion unit comprising a nacelle and an aircraft turbojet engine, the operating assembly (31) being characterized in that it comprises: - an operating cowl (35) which covers at least half of the circumference of the outer wall (37) of the air intake duct (33) of the nacelle when the propulsion unit is mounted on the operating assembly (31), - at least two connections (43) for fastening slings for connection to a lifting system (47) outside the operating assembly (31), The operating assembly is characterized in that the operating assembly comprises an expandable flexible element (57), which, when expanded, contacts at least the inner wall of the air inlet (33) of the cabin when the propulsion unit is mounted on the operating assembly (31).

2. The operating assembly (31) according to claim 1, wherein: The operating housing (35) further comprises at least two receiving pockets (49) for receiving the at least two connecting portions (43) for fastening the sling, the pockets being configured to hold the at least two connecting portions (43) for fastening the sling in position on the operating housing (35).

3. The operating assembly (31) according to claim 2, characterized in that One of the at least two connecting parts (43) for fastening the sling comprises: - a plate (51) shaped to be inserted into one of the at least two receiving pockets (49), and - a sling fastening fitting (53) designed to receive one of said slings, said sling fastening fitting being fixed to said plate (51).

4. The operating assembly (31) according to any one of claims 2 or 3, characterized in that: The at least two receiving pockets (49) for receiving the at least two connecting portions (43) for fastening slings are positioned on either side of the longitudinal plane of the operating assembly (31).

5. The operating assembly (31) according to claim 1 or 2, characterized in that: The operating cowl (35) comprises a transverse extension (39) shaped to at least partially cover the circumference of a downstream edge (41) of the air inlet (33) of the nacelle when the propulsion unit is mounted on the operating assembly (31).

6. The operating assembly (31) according to claim 1 or 2, characterized in that: When the inflatable flexible element (57) is inflated and when the propulsion unit is mounted on the operating assembly (31), the inflatable flexible element (57) occupies the entire internal space defined by the inner wall of the air inlet duct (33) of the nacelle.

7. The operating assembly (31) according to claim 1 or 2, characterized in that: The inflatable flexible element (57) comprises an upstream protrusion (61) which comes into contact with the leading edge of the air inlet (33) of the nacelle when the inflatable flexible element (57) is inflated and when the propulsion unit is mounted on the operating assembly (31).

8. The operating assembly (31) according to claim 1 or 2, characterized in that: The operating assembly comprises main fastening straps (65), each of which has a first end (67) attached to the expandable flexible element and a second end (69) attached to the operating housing (35).

9. The operating assembly (31) according to claim 1 or 2, characterized in that: The operating assembly comprises a circumferential main band (75) positioned on a flange in order to fasten the air inlet (33) of the nacelle upstream of the fan case of the turbojet engine.

10. The operating assembly (31) according to claim 9, characterized in that The operating assembly comprises additional fastening straps (77), each of which has a first end attached to the circumferential main strap (75) and a second end attached to the operating housing (35).

11. A method for operating a propulsion unit, the propulsion unit comprising: - a nacelle including an air intake (33), and - an aircraft turbojet engine (71) comprising a fan casing to which the air inlet (33) of the nacelle is attached, The operating method is characterized in that it comprises the following consecutive steps: - covering at least half of the circumference of the outer wall (37) of the air inlet duct (33) of the nacelle with an operating cover (35) of an operating assembly according to claim 1 or 2; - positioning at least two connecting parts (43) of an operating assembly according to claim 1 or 2 for fastening a sling on the operating housing (35); - connecting the at least two connecting parts (43) for fastening the slings to a lifting system outside the operating assembly (31) via slings; - Disassembling the air inlet (33) from the fan casing of the turbojet engine (71).

12. The operating method according to claim 11, characterized in that: The operating method comprises, before the step of covering at least half of the circumference of the outer wall of the air inlet duct of the nacelle with the operating cover, a first additional step aimed at inflating the inflatable flexible element (57) of the operating assembly (31) in the internal space defined by the inner wall of the air inlet duct (33) of the nacelle until the flexible element is in contact with at least the inner wall of the air inlet duct (33) of the nacelle.

13. The operating method according to claim 12, characterized in that: The operating method comprises, after the step of disassembling the air inlet from the fan casing of the turbojet engine, a second additional step aimed at securing the operating assembly (31) by attaching a first end (67) of each of the main fastening straps (65) to the expandable flexible element (57) and attaching a second end (69) of each of the main fastening straps (65) to the operating housing (35).

14. The operating method according to claim 13, characterized in that: The operating method comprises, before the step of removing the air inlet (33) from the fan casing of the turbojet engine (71), a third additional step aimed at installing a circumferential main belt (75) on the fastening flange (73) of the air inlet (33) of the nacelle upstream of the fan casing of the turbojet engine and at attaching the main belt (75) to the inflatable flexible element of the operating cover (35) by means of an additional fastening belt (77).

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