ASSEMBLY METHOD AND ASSEMBLY AID WITH MAGNETIC ELEMENT

Abstract

The proposed solution relates in particular to a method for assembling an engine assembly having a first engine component and a second engine component, wherein at least one fastening element is first of all arranged on an assembly aid, the at least one fastening element is arranged on the first engine component via the assembly aid and is held in an assembly position under the action of at least one magnetic element of the assembly aid, the at least one fastening element is fixed to the second engine component, and the assembly aid is removed again from the first engine component.

Claims

1. A method for assembling an engine assembly having a first engine component and a second engine component, wherein at least one fastening element is first of all arranged on an assembly aid, the at least one fastening element is arranged on the first engine component via the assembly aid and is held in an assembly position under the action of at least one magnetic element of the assembly aid, the at least one fastening element is fixed to the second engine component, and the assembly aid is removed again from the first engine component.

2. The method according to claim 1, wherein the first engine component and the second engine component are connected to each other only after the at least one fastening element has been arranged on the first engine component via the assembly aid.

3. The method according to claim 1, wherein the at least one fastening element is first of all transferred from its assembly position into an intermediate position, in which the at least one fastening element is fixed to the second engine component, the assembly aid is then removed and the at least one fastening element is subsequently transferred from the intermediate position into a securing position, in which the first engine component and the second engine component are secured to each other via the at least one fastening element.

4. The method according to claim 1, wherein the at least one fastening element is plugged onto the assembly aid and/or is suspended on the assembly aid.

5. The method according to claim 1, wherein the assembly aid is removed from the first engine component by a pull being exerted on the assembly aid.

6. The method according to claim 1, wherein at least two fastening elements provided for securing the first and second engine components are arranged on the assembly aid, said fastening elements being arranged together on the first engine component via the assembly aid and each being held in an assembly position under the action of the at least one magnetic element of the assembly aid.

7. The method according to claim 1, wherein the at least one fastening element is arranged on a flange section of the first engine component via the assembly aid.

8. The method according to claim 1, wherein at least two assembly aids having in each case at least one fastening element are used for the assembly of the engine assembly.

9. An assembly aid for assembling an engine assembly, wherein the assembly aid has a holding body which is provided for the arrangement of at least one fastening element and on which at least one magnetic element is provided for fixing the assembly aid to an engine component of the engine assembly.

10. The assembly aid according to claim 9, wherein the holding body has at least one holding opening onto which the at least one fastening element can be plugged and/or on which the at least one fastening element can be suspended.

11. The assembly aid according to claim 10, wherein the at least one holding opening is designed as a laterally open through opening.

12. The assembly aid according to claim 9, wherein the holding body for the arrangement of at least two fastening elements is formed on the assembly aid.

13. The assembly aid according to claim 10, wherein the holding body has two holding openings with an intermediate section which is present between the holding openings and on which the at least one magnetic element is provided.

14. The assembly aid according to claim 9, wherein a plurality of magnetic elements are provided on the holding body.

15. The assembly aid according to claim 9, wherein the holding body is in the shape of a circular ring segment.

Description

[0034] In the figures:

[0035] FIGS. 1A-1B show perspective views of a variant embodiment of an assembly aid with a plurality of holding openings for fastening elements suspended thereon and with a plurality of magnets on intermediate webs provided between the holding openings;

[0036] FIG. 2 shows a perspective and partially sectioned view of a first engine component with fastening elements attached to a flange section via the assembly aid of FIGS. 1A and 1B;

[0037] FIG. 3A shows an enlarged and sectioned illustration of the first engine component with a second engine component fitted thereon, with the fastening elements in an assembly position corresponding to FIG. 2;

[0038] FIG. 3B shows a sectioned illustration comparable to FIG. 3A of a fastening element in an intermediate position, in which the fastening element is fixed to the second engine component and before the assembly aid is removed;

[0039] FIG. 4 shows a flow diagram for a variant embodiment of a proposed assembly method;

[0040] FIG. 5 shows schematically and in a sectional illustration a gas turbine engine, in which a proposed assembly aid and a proposed assembly method are used for connecting engine components.

[0041] FIG. 5 illustrates, schematically and in a sectional illustration, a (gas turbine) engine T, in which the individual engine components are arranged one behind the other along an axis of rotation or central axis M. The engine T is designed by way of example as a turbofan engine. At an inlet or intake E of the engine T, air is drawn in along an inlet direction R by means of a fan F. This fan F, which is arranged in a fan casing FC, is driven by means of a rotor shaft RS which is set in rotation by a turbine TT of the engine T. The turbine TT here adjoins a compressor V, which has, for example, a low-pressure compressor 11 and a high-pressure compressor 12, and optionally also a medium-pressure compressor. The fan F on the one hand supplies air to the compressor V and on the other hand supplies air to a secondary flow duct or bypass duct B, in order to generate thrust. The bypass duct B runs here around a core engine, which comprises the compressor V and the turbine TT and comprises a primary flow duct for the air supplied to the core engine by the fan F.

[0042] The air conveyed into the primary flow duct via the compressor V enters a combustion chamber section BK of the core engine, in which the driving energy for driving the turbine TT is generated. For this purpose, the turbine TT has a high-pressure turbine 13, a medium-pressure turbine 14 and a low-pressure turbine 15. The energy released during the combustion is used here by the turbine TT to drive the rotor shaft RS and thus the fan F in order to generate the required thrust by means of the air conveyed into the bypass duct B. The air from the bypass duct B and the exhaust gases from the primary flow duct of the core engine flow out via an outlet A at the end of the engine T. In this arrangement, the outlet A generally has a thrust nozzle with a centrally arranged outlet cone C.

[0043] In principle, the fan F can also be coupled to the low-pressure turbine 15, and can be driven by the latter, via a connecting shaft and an epicyclic planetary transmission. It is furthermore also possible to provide other gas turbine engines of different configurations in which the proposed solution can be used. For example, engines of this type can have an alternative number of compressors and/or turbines and/or an alternative number of connecting shafts. As an example, the engine can have a split-flow nozzle, meaning that the flow through the bypass duct B has its own nozzle, which is separate from and situated radially outside the core engine nozzle. However, this is not limiting, and any aspect of the present disclosure may also apply to engines in which the flow through the bypass duct B and the flow through the core are mixed or combined before (or upstream of) a single nozzle, which may be referred to as a mixed-flow nozzle. One or both nozzles (whether mixed flow or split flow) may have a fixed or variable region. While the described example relates to a turbofan engine, the proposed solution may be applied, for example, to any type of gas turbine engine, such as an open-rotor (in which the fan stage is not surrounded by an engine nacelle) or turboprop engine, for example.

[0044] During the assembly of engine assemblies of the engine T, engine components are in practice generally secured to one another very substantially manually by a fitter, in particular since possible securing points of two engine components are not readily accessible by an assembly robot. Possible fastening elements for securing two engine components to each other also have to be frequently pre-positioned on one of the engine components before the two engine components are arranged on each other since, following a corresponding arrangement and the thus predetermined spatial orientation of the engine components, the corresponding fastening points are still accessible at most to a limited extent.

[0045] In practice, it is frequently conventional to provide holding elements for this purpose on one of the engine components, via which holding elements a corresponding fastening element can be held in a pre-assembly position on the one engine component until securing to the other engine component can be undertaken via said fastening element. Corresponding holding elements are integrated here on the engine component and remain on the engine assembly even after the assembly. Said holding elements therefore in particular increase the weight of the engine assembly although they have no function after the assembly.

[0046] By contrast, in one variant embodiment of the proposed solution, a separately mountable assembly aid is provided which can be removed again from the engine component during the assembly process. In particular, such a corresponding assembly aid can be used repeatedly for the assembly of a plurality of engine assemblies.

[0047] The assembly aid 1 illustrated in FIGS. 1A and 1B is provided with, for example, a holding body 10 on which a plurality of fastening elementshere in each case in the form of screw bolts 2can be arranged, said fastening elements being provided for securing two engine components to each other. The holding body 10 of the assembly aid 1 of FIGS. 1A and 1B is designed in the shape of a circular ring segment and therefore has a concavely curved inner side 10i and a convexly curved outer side 10a facing away therefrom.

[0048] For the arrangement of the plurality of screw bolts 2 on the holding body 10, a plurality of holding openings 101here more than two, namely five holding openings 101are provided on the holding body 10. Each holding opening 101 is designed as a through opening and is additionally laterally open towards the outer side 10a of the holding body 10 such that a screw bolt 2 can also be plugged onto and suspended on the holding body 10 via the outer side 10a.

[0049] Each elongate screw bolt 2 has a bolt head 20 at one end and a threaded section 22 at the opposite end. A stem section 21 which has a smaller diameter than the threaded section 22 and therefore a smaller cross-sectional area extends between the threaded section 22 and the bolt head 20. The diameter of the stem section 21 and the width of a holding opening 101 are coordinated with each other in such a manner that there is space for the stem section 21 in a holding opening 101. By contrast, the threaded section 22 is dimensioned in such a manner that it does not fit through a holding opening 101. Each screw bolt 2 therefore rests in the region of a transition between its stem section 21 and its threaded section 22 on the edge of the respective holding opening 101 and is thus held suspended in a form-fitting manner on the holding body 10 of the assembly aid 1.

[0050] A respective intermediate section in the form of an intermediate web 102 extends between the holding openings 101 of the assembly aid 1. A magnet 11 is provided on each of said intermediate webs 102. The assembly aid 1 can be fixed to a (first) metallic engine component 3 according to FIG. 2 via said magnets 11. Under the action of the magnets 10, the assembly aid 1 can therefore be used to arrange a plurality of screw bolts 2 together on the engine component 3 and hold same in an assembly position.

[0051] In the illustrated variant embodiment, the screw bolts 2 are required, for example, for securing the first engine component 3 and a second engine component 4 to each other. The first and second engine components 3 and 4 are intended to be secured to each other here via end-face flange sections 30 and 40. Each of said flange sections 30 and 40 here has an end face with a double-row toothing for a form-fitting connection between the two engine components 3 and 4 arranged on each other as specified. However, the final securing of the two engine components 3 and 4 is undertaken only via a plurality of screw bolts 2 to be arranged along the circumference of the flange sections 30 and 40.

[0052] For the connection of the two engine components 3 and 4, a (first) engine component 3 has to be positioned here in such a manner that the screw bolts 2 are accessible from below with respect to a vertical. The assembly aid 1 with the plurality of screw bolts 2 is therefore fitted to the flange section 30 along an assembly direction MR, for example counter to the gravitational force. The flange section 30 of the first engine component 3 forms an assembly surface 300 which is in the shape of a circular ring and on which a plurality of through openings or bores 302 following one another along the circumference are provided for the screw bolts 2. Via the magnets 11 of the assembly aid 1, the assembly aid 1 remains locked on the assembly surface 300 of the first engine component 3 and therefore captively holds the screw bolts 2 in an assembly position, in which the threaded sections 22 thereof project through the respective through openings 302 of the assembly surface 300 and protrude on the end face 301 of the flange section 30 between the two toothing rows of the first engine component 3.

[0053] If, subsequently, according to FIG. 3A, the second engine component 4 is arranged on the first engine component 3, there is already a form-fitting connection between the two engine components 3 and 4 via the end faces 301 and 401, with the double-row toothings, on their flange sections 30 and 40. Furthermore, through openings or bores 402 are likewise provided on the flange section 40 of the second engine component 4 between the toothing rows. When the first and second engine components 3 and 4 are arranged on each other as specified, the flange-side through openings 302 and 402 of the first and second engine components 3 and 4 are aligned with each other. If the two engine components 3 and 4 are positioned on each other as specified, the threaded sections 22 of the screw bolts 2 held on the first engine component 3 via the assembly aid 1 consequently project into the through openings for 402 of the second engine component 4. A clearance fit is provided here between a through opening 402 and an associated screw bolt 2.

[0054] Each through opening 402 of the second engine component 4 is joined by a sleeve section 403 with an internal thread. A screw bolt 2 is fixed to and therefore held on the second engine component 4 only by being screwed into said sleeve section 403.

[0055] During the further assembly process, according to FIG. 3B each screw bolt 2 is transferred from the assembly position into an intermediate position by each screw bolt 2 being screwed by a predetermined minimum amount into the associated sleeve section 403 of the second engine component 4. A screw bolt 2 is thereby fixed to the second engine component 4. Accordingly, a screw bolt 2 then no longer lies against the assembly aid 1 via the threaded section 22 and consequently also no longer has to be secured via the assembly aid 1 against dropping out. The assembly aid 1 can accordingly be removed from the assembly surface 300 of the first engine component 3.

[0056] If all of the screw bolts 2 which have been previously arranged on the assembly aid 1 are at least partially screwed into associated sleeve sections 403 of the second engine component 4, the assembly aid 1 is pulled off from the assembly surface 300. For this purpose, a pull is exerted, for example, on a tension element which is provided on the inner side 10i of the holding body 10. Examples of such a tension element are a belt, a clip or a cable. For example, said tension element is produced from Kevlar. The holding body 10 can be pulled off from the screw bolts 2 through the holding openings 101, which are each open laterally, and can therefore be separated. All that is necessary is to overcome the magnetic force applied by the magnets 11, in order to pull off the assembly aid 1 from the assembly surface 300 of the first engine component 3 counter to the original assembly direction MR.

[0057] After removal of the assembly aid 1, the screw bolts 2 are then each completely screwed in such that the two engine components 3 and 4 are thereby secured to each other at their flange sections 30 and 40.

[0058] A plurality of assembly aids 1 can be used simultaneously for arranging all of the screw bolts 2 along the circumference of the flange section 30 of the first engine component 3, For example, each assembly aid 1 with its holding body 10 covers a quarter of the circumference of the flange section 30 such that, via a total of four assembly aids 1, all of the screw bolts 2 provided for the securing can be captively positioned in an assembly position on the flange section 30 of the first drive component 3 under the action of the respective magnetic elements 11. After all of the screw bolts 2 have been transferred into the intermediate position, illustrated by way of example for one screw bolt 2 in FIG. 3B, and are therefore fixed to the second engine component 4 (without already taking up their final securing position), the assembly aids 1 are pulled off from the first engine compartment 3. Subsequently, all of the screw bolts 2 are tightened and are therefore completely screwed in such that they are in their respective securing position and the two engine components 3 and 4 are thereby fixed to each other as specified at the flange sections 30 and 40. The assembly aids 1 are thereby reusable and can be used for the following assembly of a further engine assembly.

[0059] The basic procedure of an above-discussed variant embodiment of a proposed assembly method is illustrated once again with reference to the flow diagram of FIG. 4.

[0060] After the first engine component 3 and one or more assembly aids 1 have been provided in a method step 40, first of all, in a method step 41, a plurality of screw bolts 2 are in each case arranged on the holding body 10 of an assembly aid 1. Then, in a method step 42, the assembly aid 1 with the screw bolts 2 held thereon is fitted along the assembly direction MR onto the assembly surface 300 of the flange section 30 of the first engine component 2. The screw bolts 2 are then held in an assembly position on the first engine component 1 via the plurality of magnets 11 of the assembly aid 1. Optionally, further assembly aids 1 are attached to in each case at least one further screw bolt 2 in order to occupy all of the through openings 302 on the flange section 30 of the first engine component 1 with screw bolts 2.

[0061] When the assembly aid(s) 1 is (are) attached, the first engine component 3 can already be positioned as specified relative to the second engine component 3 and therefore can optionally also already be connected to said second engine component 4 at the flange sections 30 and 40. Alternatively, the two engine components 3 and 4 can be fitted to each other only after the first engine component 3 already has the screw bolts 2 held thereon via the assembly aid(s) 1. In particular, a spatial orientation of the engine component 3 can be changed and therefore, for example, the first engine component 3 can be rotated after the first engine component 3 has already been fitted with the screw bolts 2 via the assembly aid(s) 1.

[0062] In a subsequent method step 43, the screw bolts 2 are first of all transferred into the intermediate position by each screw bolt 2 being screwed into an internal thread on the second engine component 4. Such an internal thread is formed, for example, by the sleeve section 403 corresponding to FIGS. 3A and 3B.

[0063] If all of the screw bolts 2 of an assembly aid 1 are therefore present in a manner at least partially secured on the second engine component 4, the assembly aid 1 is removed and consequently pulled off counter to the applied magnetic force. This is provided in a method step 44 of FIG. 4.

[0064] Finally, in a method step 45, the screw bolts 2 are tightened and the first and second engine components 3 and 4 are thereby secured to each other as specified.

LIST OF REFERENCE SIGNS

[0065] 1 Assembly aid [0066] 10 Holding body [0067] 101 Holding opening [0068] 102 Intermediate web (intermediate section) [0069] 10a Outer side [0070] 10i Inner side [0071] 11 Magnet [0072] 2 Screw bolt (fastening element) [0073] 20 Bolt head [0074] 21 Stem section [0075] 22 Threaded section (fastening section) [0076] 3 1st Engine component [0077] 30 Flange section [0078] 300 Assembly surface [0079] 301 End face [0080] 302 Through opening/bore [0081] 4 2nd Engine component [0082] 40 Flange section [0083] 401 End face [0084] 402 Through opening/bore [0085] 403 Sleeve section with internal thread [0086] A Outlet [0087] B Bypass duct [0088] BK Combustion chamber section [0089] E Inlet/Intake [0090] F Fan [0091] M Central axis/axis of rotation [0092] MR Assembly direction [0093] R Inlet direction [0094] RS Rotor shaft [0095] T Gas turbine engine [0096] TT Turbine [0097] V Compressor