Connecting strut for service conduits in a turbofan engine

0001The invention relates to a turbofan engine having an outer casing of the secondary flow.

0002A turbofan engine comprises, functionally, an air inlet duct, a fan, a compressor, a combustion chamber, a turbine and an exhaust nozzle. These elements are contained in casings.

0003Generally, it is suspended to the structure of an aircraft by two housings: a housing intermediate said, placed just downstream of the retention casing of the fan blades, and an exhaust casing to the rear of the engine.

0004In the case, for example, where a turbojet is placed on the fuselage of an aircraft, usually in the rear position, the secondary air flow must be contained and guided along the jet engine to the exhaust casing. In this guiding purpose, a casing of structural external secondary flow, called "outer fan duct", is placed between the intermediate housing and a suspension ring connected to the exhaust case by a series of rods. The outer casing of structural secondary flow has a dual function, restraining and guiding the secondary air flow, first, recovery of the thrust forces on the other.

0005The annular flow of secondary air is guided on its inner surface by an inner casing called "inner fan duct", positioned generally concentrically to the structural outer housing between the inner base of the arm of the intermediate casing and the exhaust casing.

0006The various fluids required for the operation of the jet engine, such as fuel, oil, and the control fluid engine accessory organs, must be routed from outside the jet engine, in particular outside the structural outer casing, towards its core, that is to say, the enclosure defined by the inner housing, containing the compressor, the combustor, the turbine and the nozzle. This routing is performed by generally known servitudes pipes. The invention particularly relates to the passage easements between the external casing of the secondary flow and the inner casing.

0007The document <patcit id="pcit0001" dnum="US20030019205A1"><text>US 2003/0019205 A1</text></patcit> discloses a combustion arm to eject the fuel in a gas turbine engine.

0008On the <figref idrefs="f0001">figure 1</figref>, Which partially shows the elements of the casing, a jet engine 1 of the prior art, there is shown a middle housing 2 and a suspension ring 3. The ring is fixed to the exhaust casing, not shown, by connecting rods . A structural outer casing 4 mounted between the housing 2 and the ring 3 comprises access hatches 5 distributed around its circumference, allowing access to the interior of the chamber defined therein, and in particular the inner casing. It is through these doors that are mounted 5 easements 7.

0009Referring to <figref idrefs="f0001">2</figref>The inner casing comprises a plurality of plates 6 of panel support extending longitudinally between the base of the arms of the intermediate casing and the exhaust casing. They are intended to support panels that define the surface of the inner casing. Easement 7 are supplied and attached to these carrier plates of panels 6, which the operator has access by access doors 5 of the structural outer casing 4, a flange 8 projecting radially from the plates 6. In this sole 8 is then mounted between the structural outer casing 4 and non-structural internal casing, envelopment profiled shirt easements 7, to ensure their protection and good flow of the gas stream. Mounting the profiled sleeve is made also by the trap 5. The latter can then be closed.

0010The assembly of servitude s as just described has many disadvantages. It is very tedious, easements must be mounted one by one on the base, according to a specific assembly order. Access to the inner casing from the doors of the structural external housing is also impractical. Maintenance or disassembly finally present the same drawbacks as the mounting.

0011The invention aims to simplify the assembly, disassembly and maintenance easements passing between the outer casing structural and non structural inner casing of a jet engine.

0012According to the invention a dual-flow turbojet, comprising an outer casing of the secondary flow, an inner casing of the secondary flow, the fluid transport easement located outside the outer casing of the secondary flow, the fluid transport easement located inside of the inner casing of the secondary flow, is characterized in that at least one removable modular arm forming ancillary-connection is arranged between said outer casing and said inner casing.

0013Thanks to the invention, the connection of external easements to the outer casing of the secondary flow, domestic servitude to the inner casing, is simply done using a removable modular arm, it is easy to mount and dismount. Indeed, since it is modular, the arm forms a whole composed of a set of standard elements préféfini; its removable nature means the ability to remove, in its modular set.

0014This arm can also be calibrated for different applications or different jet engines.

0015Preferably, the non-structural internal housing having panels and longitudinal plates of the bearing panels, at least one longitudinal plate panel support comprises a receiving plate of a removable modular arm.

0016According to another feature, the outer casing comprises at least one orifice for passage of a removable modular arm.

0017According to another feature, the modular arm includes piping elements comprising external connection means to constraints, and intended to be inserted in channels opening onto the external face of the plate.

0018Advantageously in this case, the channels also open on at least one different face of the plate and comprise coupling means to constraints.

0019Advantageously, the outer face of the plate comprises a recess for receiving the modular arm, wherein the channels are drilled.

0020The invention relates, as intermediate product, a removable modular arm for the turbojet presented above, comprising a sheet pierced by calibrated passage of piping elements orifices calibrated pipe elements and a profiled jacket s adapting to the plate.

0021Preferably, the piping elements comprise at one of their ends, connecting means to constraints.

0022Preferably, the piping elements comprise at one of their ends, a sealing O-ring.

0023Preferably, the sheet comprises a recess, on which are drilled the holes, to be fitted into the profiled liner.

0024The invention will be better understood using the following description of the preferred embodiment of the turbojet engine and its modular arm coupling easement of the invention, with reference to the accompanying drawings, in which:<ul><li>the <figref idrefs="f0001">figure 1</figref> shows a schematic perspective view of a jet engine casing of the prior art; </li><li>the <figref idrefs="f0001">2</figref> shows a schematic perspective view of the easement mounted on an inner casing supporting plate of the prior art;</li><li>the <figref idrefs="f0002">3</figref> shows a sectional side view of the jet engine of the invention;</li><li>the <figref idrefs="f0002">4</figref> shows a schematic perspective view of a portion of the modular arm of the invention;</li><li>the <figref idrefs="f0002">5</figref> shows a schematic bottom view partly in section of the modular arm of the invention;</li><li>the <figref idrefs="f0003">6</figref> shows a schematic perspective view of another part of the modular arm of the invention;</li><li>the <figref idrefs="f0003">7</figref> shows a side view of the modular arm of the invention;</li><li>the <figref idrefs="f0003">8</figref> shows a schematic perspective view of the panel supports of the non-structural inner casing of the turbojet engine of the invention;</li><li>the <figref idrefs="f0004">9</figref> shows a cross sectional view of a panel support of the non-structural internal casing of the turbojet, wherein are inserted the pipe elements of the modular arm of the invention, and</li><li>the <figref idrefs="f0004">Figure 10</figref> shows a schematic front view of the jet engine of the invention.</li></ul>

0025Referring to <figref idrefs="f0002">3</figref>The turbojet 10 of the invention comprises, from upstream to downstream in the direction of the gas flow, an air inlet duct, a fan 11, a compressor 12, a combustor 13, a turbine 14 and an exhaust duct 15. the blower is contained in a fan retention casing 16, downstream of which is mounted an intermediate casing 17, supported by arm 18 resting on an annular inner base 19 extending around the casing compressor 20. the conduit 15 is contained in an exhaust casing 21. a suspension ring 22, intended to be fixed to a suspension of the turbojet engine in a plane, is fixed to the exhaust casing 21 by not shown connecting rods.

0026Between the annular inner base 19 on the one hand, and the exhaust casing 21, on the other hand, is mounted an inner casing 23, non-structural, commonly called "inner fan duct", which wraps the core of the turbojet 10, in order to contain and guide the secondary flow flowing to the outside thereof.

0027Between the intermediate casing 17, on the one hand, and the suspension ring 22, on the other hand, is mounted an outer casing of the secondary flow 24, structural, commonly called "outer fan duct", whose function is to contain and guide on its outer surface, the secondary flow flowing outside the core of the turbojet engine 10, but also to take the thrust forces between the suspension ring 22 and the intermediate casing 17, which is connected to the another suspension of the turbojet 10 to the plane.

0028According to the invention, a modular radial arm 25 easements connector is disposed in order to connect easements between the external casing 24 and the inner casing 23. Its role is to ensure continuity between easements located outside the outer casing of the secondary stream 24 and other located inside the inner casing 23.

0029Referring to <figref idrefs="f0002">4</figref>The modular arm 25 includes a generally rectangular plate 26, slightly curved, wherein is formed a recess 27, here oval. In the recess 27 are drilled holes 28 passing piping elements 29, here ten in number. More specifically, in each hole 28, a pipe member 29 can be inserted and fixed, for example by bolting, at this orifice 28, as will be seen more precisely below. The 29 pipes metal elements are here.

0030Each channeling member 29 is a bonded connection between a bonded outside the external casing 24 and its extension inside the inner casing 23. Each pipeline element 29 is calibrated to the bondage which it ensures the fitting function. The diameter of the orifice 28 is calibrated to the section of pipe 29 it receives.

0031By internal or external, to a room or part of a workpiece will be understood later, a portion that, once mounted, is placed respectively radially inwards or outside the turbojet engine 10.

0032Referring to <figref idrefs="f0002">5</figref>, Each conduit member 29 includes a skirt 31 for positioning and sealing, which in turn is integral and is intended to abut on the inner face of the recess 27. Thus, during assembly of the modular arm 25, each conduit member 29 is inserted, by its end nearest to the skirt 31, in the orifice 28 which is intended for it, until the skirt 31 abuts the inner face of the recess 27. A nut 30 is then screwed on a thread of the pipe member 29 provided for this purpose on the outer side of the recess 27, ensuring the maintenance of the pipe member 29 in its hole 28, between the nut 30 and the skirt 31. on the other intermediate sealing parts or positioning, in particular the outer side of recess 27, may be provided. At the end closest to the skirt 31, 29 of piping elements comprise, beyond the nut 30, connecting means 50 to a bonded, for example by a thread 50 on the pipe member 29 considered. These connection means 50 are used to connect the easement located outside of the outer casing 24, and for which we want to make a connection with an easement within the enclosure defined by the inner casing 23, at the channeling member 29, which has previously been sized to ensure that connection.

0033All 29 lines of elements are fixed in their respective opening 28. It is expected the same number of holes 28 as piping elements 29. If this were not the case, the unused 28 holes are plugged. In the illustrated embodiment of the invention, the pipes 29 elements have a bend 32 near their skirt 31 and extend generally linearly on either side of the bend 32. The elements 29 piping all have the same form, except for their diameter, and thus all extend parallel to each other when mounted.

0034Referring to <figref idrefs="f0003">6</figref>The removable modular arm 25 of the invention further comprises a shaped jacket 33. The jacket 33 comprises a jacket body 34 of generally oval cross section, corresponding to the oval shape of the recess 27, and elongated so as to adapt to the distance between the inner casing 23 of the outer casing 24. the liner 33 is hollow and open at both ends, and comprises an outer rim 35, generally perpendicular to the liner body 34, and the shape corresponding to the shape of the sheet 26 .

0035The oval shape is due to the departure to the oval shape that is desired to give to the jacket 33 of the modular arm 35. In effect, once the mounted jet engine, the liner 33 extends between the inner casing 23 and the outer casing 24, therefore in the secondary flow, its shape to be adapted according to the flow of the secondary flow around it. The oval shape can of course be replaced by any suitable form.

0036Referring to <figref idrefs="f0003">7</figref>But also the <figref idrefs="f0002">5</figref>The modular arm 25 of the invention, when assembled, comprises the plate 26, on which are fixed the pipe elements 29, around which is fitted the shaped jacket 33, whose shape adapts to the whole. The rim 35 of the liner 33 is arranged, as we have seen, to match the shape of the inner face of the sheet 26, the recess 27 of the sheet being embedded, on the inside where it projects in the body 34 of the jacket 33, dimensioned to this end. The liner 33 is secured by welding or soldering, for example, plate 26, forming with it and piping elements 29, the modular arm 25 of the invention. Once the assembled arm 25, the piping members 29 protrude opposite to the sheet 26, from the enclosure defined by the liner 33.

0037Referring to <figref idrefs="f0003">8</figref>, The inner casing 23 comprises a plurality of longitudinal plates panel supports 36, here four in number, which, together with other retaining elements such as ring 37, the armature of the inner casing 23. With reference to the <figref idrefs="f0004">Figure 10</figref>, The inner casing 23 is formed when the panels 38 are placed between the supports of successive panels 36, wedged in recesses 47 provided for this purpose, thus creating the required surface for wrapping the core of the turbojet engine 10 and the flow guide secondary.

0038On the panel supports 36, in the central part which is not in contact with the panels 38, is arranged a plate 39 for receiving a modular arm 25 fitting easement. Such a plate 39 comprises a longitudinal recess 40, forming a shoulder 41 which follows a generally oval shape corresponding to the inner end section of the jacket 33 of the modular arm 25.

0039Referring to <figref idrefs="f0004">9</figref>The recess 40 is drilled with a plurality of channels 42, here ten in number, for receiving and fitting of pipe elements 29 of the modular arm 25 of the invention. Each channel 42 comprises a portion 43 opening onto the surface of the recess 40, here in a front view perpendicular to that surface, a bend 51 and a portion 44 parallel to the surface of the recess 40, thus perpendicular to the first portion 43, opening onto a lateral longitudinal wall of the support 36 in which the channel 42 is pierced. In the preferred embodiment of the jet engine 10 of the invention, two parallel rows of five channels 42 are pierced on the recess 40, the channels 42 opening, according to the row to which they belong, on either longitudinal side walls of the carrier 36. of course, instead of lead on the side faces of the holder 36, the channels 42 lead to its inner face.

0040It is possible to connect, at the portion 44 of a channel 42 opening on the side of the support 36, properly dimensioned, an easement 45 located within the enclosure defined by the non-structural inner case 23. couplings 46, well known in the art, can be provided for this purpose on the support 36. the connections 46 and 42 channels of course are sized according to the servitude to which they must serve fitting.

0041Each channel 42 is dimensioned, in its portion 43 opening onto the surface of the recess 40 for receiving the end of a pipe member 29. The latter can be provided with an O-ring 48 sealing. In the exemplary embodiment of the invention described herein, the ten channels 42 are each dimensioned to receive the end of the pipe element 29 of the modular arm 25 corresponding to their position.

0042The distribution and diameter of the channels 42 on the surface of the recess 40 of the holder 36 is comparable to the distribution and diameter of the orifices 28 on the surface of the recess 27 of the modular arm 25. The plate 39 is arranged and designed to exactly receiving a modular arm 25 particular: its channels 42 are arranged to receive the pipe elements 29, while the shoulder 41 of the recess 40 is arranged to support the inner end of body 34 of jacket 33.

0043Mounting easement and connection between the external casing 24 and the inner casing 23 of the jet engine 10 of the invention will now be described in more detail, taking the example of a connection by a single modular arm 25.

0044The panel supports 36 of the inner casing 23 of the turbojet engine 10 are mounted around the core of the turbojet engine 10, between the inner base 19 of the arm 18 of the intermediate casing 17 and the exhaust casing 21. The auxiliary services, extending the inside the chamber to be defined by the inner casing 23 and intended to be connected with easement located outside of the outer casing 24 are then connected to the portions 43 of channels 42 that are intended for them on the fittings 46, provided for this purpose, the support 36 on which is arranged the plate 39 for receiving the modular arm 25.

0045This internal connection is performed, it is possible to place the panels 38 to their supports 36 and thereby form the non-structural inner case 23. The outer structural casing 24 is then mounted between the intermediate casing 17 and the suspension ring 22 .

0046The modular arm 25 is then slipped through an opening 49 oval provided for this purpose on the external casing 24, between the latter and the inner casing 23. The aperture 49 is located directly above the platen 39, so it is possible, just by inserting the arm 25 in the orifice 49, to come inserting ends pipes 29 of the elements in the portions 43 of pipes 42 of the plate 39 for receiving them, without need for access to the space defined by the inner casing 23 and the outer casing 24. the sheet 26 of the arm 25 is then removably attached to the structural outer casing 24, for example with inserts or other suitable means. It may also be brazed, which however make more difficult a dismounting operation of the arm 25.

0047Easement extending outside the outer casing 24, and to be connected to the aforementioned internal easement, can then be connected to the connection means 50 conduits 29 elements, the choice obviously depending performing bondage already connected to each conduit member 29 through the plate 39.

0048Thus, thanks to the modular arm 25 of the invention, the connector easements between the structural outer casing 24 and the non-structural internal casing 23 is provided, the arm 25, in cooperation with the plate 39 and the orifice 49 of the outer casing structural 24, here for the fitting of easements. This connector is assembled and disassembled easily, without dismantling including internal connections made at the side walls of supports 36.

0049It goes without saying that several arm assembly 25, 39 and orifice plate 49 may be provided, either on different panel supports 36 of non-structural inner case 23, or even on the same support 36, for example along the latter.

0050In the embodiment described of the jet engine 10 of the invention, the modular arm 25, orifices 28 for passage of pipe elements 29, the piping members 29 and their connections 50, channels 42 and their connections 46 are calibrated according easements that allow you to connect. It goes without saying that all of these elements could be calibrated as standard, the connectors 46, 50 or other couplings allowing adaptation depending on the type and caliber of the easements to be connected.