ADJUSTMENT DEVICE FOR ADJUSTING SEVERAL GUIDE VANES OF AN ENGINE

Abstract

An adjustment device for adjusting several guide vanes of the engine, wherein the adjustment device includes at least one adjusting element that couples with the guide vanes and is mounted in an adjustable manner, a connection element that couples with the adjusting element, as well as a crank shaft for controlling an adjusting movement of the adjusting element, and the crank shaft has at least one coupling element which couples with the connection element and at which the connection element is hinged to transform a rotational movement of the crank shaft about a longitudinal axis of the crank shaft into an adjusting movement of the adjusting element for adjusting the guide vanes. The crank shaft has a modular design with at least two shaft modules that are arranged behind each other along the longitudinal axis of the crank shaft.

Claims

1. An adjustment device for adjusting several guide vanes of an engine, wherein the adjustment device comprises at least one adjusting element that couples with the guide vanes and is mounted in an adjustable manner, a connection element that couples with the adjusting element, as well as a crank shaft for controlling an adjusting movement of the adjusting element, the crank shaft has at least one coupling element which couples with the connection element and at which the connection element is hinged to transform a rotational movement of the crank shaft about a longitudinal axis of the crank shaft into an adjusting movement of the adjusting element for adjusting the guide vanes, and the crank shaft has a modular design with at least two shaft modules that are arranged behind each other along the longitudinal axis of the crank shaft and can be fixated in different rotational positions about the longitudinal axis relative to each other by means of at least one toothing, and the coupling element is provided at one of the at least two shaft modules of the crank shaft.

2. The adjustment device according to claim 1, wherein the adjustment device comprises at least one further adjusting element and at least one further connection element that couples with the further adjusting element, and that a further coupling element at which the further connection element is hinged is provided at another shaft module of the crank shaft.

3. The adjustment device according to claim 1, wherein at least two shaft modules are fixated relative to each other in a rotational position about the longitudinal axis of the crank shaft via an intermediate piece that meshes with a first toothing of the one shaft module and a second toothing of the other shaft module.

4. The adjustment device according to claim 3, wherein the intermediate piece has an outer toothing and respectively meshes with an inner toothing of the two shaft modules.

5. The adjustment device according to claim 3, wherein the intermediate piece is embodied as a gear wheel ring.

6. The adjustment device according to claim 1, wherein at least two shaft modules are fixated relative to each other in a rotational position about the longitudinal axis of the crank shaft by means of a Hirth toothing.

7. The adjustment device according to claim 1, wherein the coupling element is arranged at a shaft module so as to be radially adjustable between at least two adjusting positions with respect to the longitudinal axis, and can be fixated in each of the adjusting positions.

8. An adjustment device for adjusting several guide vanes of an engine, wherein the adjustment device comprises at least one adjusting element that couples with the guide vanes and is mounted in an adjustable manner, a connection element that couples with the adjusting element, as well as a crank shaft for controlling an adjusting movement of the adjusting element, the crank shaft has at least one coupling element which couples with the connection element and at which the connection element is hinged to transform a rotational movement of the crank shaft about a longitudinal axis of the crank shaft into an adjusting movement of the adjusting element for adjusting the guide vanes, and the coupling element is arranged at the crank shaft so as to be radially adjustable between at least two adjusting positions with respect to the longitudinal axis, and can be fixated in each of the adjusting positions by means of at least one toothing.

9. The adjustment device according to claim 8, wherein the coupling element has a fastening body with at least one toothed toothing surface for fixating in one of the possible adjusting positions.

10. The adjustment device according to claim 9, wherein two toothed toothing surfaces are provided at the fastening body of the coupling element, and namely at front faces of the fastening body that are facing away from each other.

11. The adjustment device according to claim 9, wherein the fastening body is received at least partially inside a recess, with a toothed toothing surface being provided at least at one inner wall of the same, acting together with the toothing surface of the fastening body.

12. The adjustment device according to claim 1, wherein the coupling element is arranged at the crank shaft so as to be radially adjustable between at least two adjusting positions with respect to the longitudinal axis, and can be fixated in each of the adjusting positions by means of at least one toothing, wherein the coupling element has a fastening body with at least one toothed toothing surface for fixating in one of the possible adjusting positions, wherein the at least two shaft modules are axially pre-stressed against one another by means of a tension rod that extends along the longitudinal axis, and the fastening body has a radially extending passage opening through which the tension rod extends and via which the fastening body can be radially adjusted with respect to the tension rod when an axial pre-stress of the shaft modules is reduced or removed.

13. The adjustment device according to claim 1, wherein the coupling element has a fork head for coupling to the connection element.

14. The adjustment device according to claim 8, wherein the coupling element has a fork head for coupling to the connection element.

15. An engine with at least one adjustment device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The attached Figures illustrate possible embodiment variants of the solution according to the invention by way of example.

[0030] FIGS. 1A-1C show, in different views, a modular crank shaft constructed with several radially adjustable coupling elements of an embodiment variant of an adjustment device for adjusting several guide vanes of an engine according to the invention.

[0031] FIGS. 2A-2B show, in an exploded view and in a perspective rendering, two shaft modules of the crank shaft of FIGS. 1A to 1C that are connected to each other in a torque-proof manner in a certain rotational position relative to each other by means of an externally toothed intermediate piece.

[0032] FIG. 2C shows an exploded view of the shaft modules of FIGS. 2A and 2B with a coupling element that has a fork head and that can be fixated at the shaft modules in different radial adjusting positions.

[0033] FIG. 3 shows the shaft module with the coupling element in the assembled state.

[0034] FIG. 4 shows two alternatively embodied shaft modules with coupling elements integrally embodied thereat and fixedly attached in a torque-proof manner at each other by means of a Hirth toothing.

[0035] FIG. 5A shows, in sections and in a perspective view, an arrangement with several guide vane assemblies as it is known from the state of the art, with respectively one guide vane row and several rotor blade assemblies.

[0036] FIG. 5B shows, based on the arrangement of FIG. 5A, an adjustment device for adjusting guide vanes of several guide vane rows by means at least one rotatable crank shaft and several coupling elements provided thereat, as it is known from the state of the art.

[0037] FIG. 6 shows, in sectional view and in a schematic manner, a gas turbine engine in which at least one guide vane assembly according to the invention is used.

DETAILED DESCRIPTION

[0038] FIG. 6 schematically illustrates, in a sectional rendering, a (gas) turbine engine T in which the individual engine components are arranged in succession along a central axis or rotational axis M. By means of a fan F, air is suctioned in along an entry direction E at an inlet or an intake E of the engine T. This fan F is driven via a shaft that is set into rotation by a turbine TT. Here, the turbine TT connects to a compressor V, which for example has a low-pressure compressor 11 and a high-pressure compressor 12, and where necessary also a medium-pressure compressor. The fan F supplies air to the compressor V, on the one hand, and, on the other hand, to a by-pass channel B for generating a thrust. The air that is conveyed via the compressor V is transported into a combustion chamber section BK where the driving power 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 turbine TT drives the fan F by means of the energy that is released during combustion in order to generate the necessary thrust by means of the air that is conveyed into the bypass channel B. The air is discharged from the bypass channel B in the area of an outlet A at the end of the engine T, where exhaust from the turbine TT flows outwards. Here, the outlet A usually has a thrust nozzle.

[0039] The compressor V comprises multiple rows of rotor blades 110 that are arranged behind each other in the radial direction, as well as rows of guide vanes 111 arranged in between them in the area of the low-pressure compressor 11. The rows of rotor blades 110 rotating about the central axis M and the rows of stationary guide vanes 111 are arranged alternatingly along the central axis M and accommodated inside a (compressor) housing 1 of the compressor V. The individual guide vanes 111 are mounted at the single-part or multi-part housing 1 in an adjustable mannerusually in addition to a radially inner bearing at the hub of the compressor V.

[0040] Here, FIG. 5A shows, in sections and in greater detail, an arrangement of rotor blade rows 12a to 12d and guide vane rows 13a to 13c for the low-pressure compressor 11 as known from the state of the art. The guide vanes 111 of the guide vane rows 13a, 13b and 13c that are arranged behind each other are mounted at the housing 1 in an adjustable manner so that the position of the guide vanes 111 can be changed depending on the compressor's rotational speed. For this purpose, a bearing journal 111a of each rotor blade 111 is mounted in a rotatable manner in a bearing opening that is embodied by a sleeve-shaped and radially outwardly protruding bearing extension 10 of the housing 1. Each bearing journal 111a is mounted and supported inside an associated bearing extension 10 so as to be rotatable about a rotational axis D. At that, each bearing journal 111a passes through an associated bearing extension 10, so that a journal end 111b projects from the bearing extension 10 at the outer side of the housing 1.

[0041] Thus, respectively one adjustment lever 31 of an (guide vane) adjustment device 3 can engage at the individual journal ends 111b to rotate the bearing journal 111a, and thus change the position of the associated guide vane 111. Here, the levers 31 of a guide vane row 13a, 13b or 13c are respectively hinged at an adjusting element in the form of an adjusting ring 30a, 30b or 30c of the adjustment device 3. The adjusting ring 30a, 30b, 30c, which is often comprised of multiple parts and divided into at least two segments, extends at the circumferential side along the outer shell surface of the housing 1. Thus, by adjusting the adjusting ring 30a, 30b, 30c, the adjustment levers 31 hinged thereat as well as multiple, usually all, guide vanes 111 of a guide vane row 13a, 13b or 13c can be adjusted. At that, the individual adjusting rings 30a, 30b, 30c for the individual guide vane rows 13a, 13b and 13c are usually adjustable independently of each other. An adjusting ring 30a, 30b, 30c is supported at an outer side of the housing 1, for example at a contact surface 114 that extends at the circumferential side.

[0042] Further, FIG. 5B shows, in sections and also in a perspective rendering, a more detailed illustration of an adjustment device 3 for adjusting the guide vanes 111 as it is known from the state of the art. Here, a crank shaft 2 for adjusting the individual adjusting rings 30a, 30b, 30c is shown in addition to the individual adjusting rings 30a, 30b, 30c for the individual rotor blade rows 13a, 13b, 13c. The crank shaft 2 is mounted at bearing blocks 4A, 4B at an outer shell surface of the housing 1 so as to be rotatable about the longitudinal axis LA. Further provided at the crank shaft 2 are several coupling elements 20.1, 20.2, 20.3 with respectively one fork head 201 at which a connection element in the form of a connecting rod 32a, 32b or 32c is hinged. Each connecting rod 32a, 32b and 32c is assigned to one of the adjusting rings 30a, 30b, 30c and connected to the same in an articulated manner. Thus, when the crank shaft 2 rotates, an adjustment force is transferred to the individual adjusting rings 30a to 30c to adjust them along the circumference in a circumferential direction U and to rotate the guide vanes 111 of the different guide vane rows 13a to 13c about their respective rotational axis D through the adjustment levers 31 that are connected to the respective adjusting rings 30a to 30c.

[0043] How strongly the individual guide vanes 111 of the different guide vane rows 13a to 13c are adjusted during rotation of the crank shaft 2 and in particular at which point in time and to what extent the individual guide vanes 111 of a guide vane row 13a to 13c are adjusted in relation to other guide vane rows 13a to 13c, significantly depends on the (angular) position of the individual coupling elements 20.1, 20.2 and 20.3 relative to each other, as well as on their radial position with respect to the longitudinal axis LA of the crank shaft 2. In the mounted state of the crank shaft 2 according to the intended use and during operation of the engine T, the positions of the coupling elements 20.1 to 20.3 are invariable and have been adjusted beforehand to the operational conditions of the engine T. However, especially during the development phase of the engine T, it is not uncommon that different transmission and adjustment ratios for adjusting the guide vanes 111 of the individual guide vane rows 13a to 13c are to be tested. For this purpose, it has turned out to be advantageous if the coupling elements 20.1 to 20.3 are embodied at the crank shaft 2 in an adjustable manner, so that the respective conditions may be varied also without exchanging the crank shaft 2. Here, it is provided that the coupling elements 20.1 to 20.3 can be adjusted radially with respect to the longitudinal axis LA of the crank shaft 2, for example according to the teaching of EP 2 949 878 A1 by means of a spline connection. However, here the radial adjustability of the individual coupling elements 20.1 to 20.3 is limited. Further, setting the rotational positions of the individual coupling elements 20.1 to 20.3 about the longitudinal axis LA relative to each other is also not possible. For this purpose, a completely new crank shaft 2 would usually have to be provided. The embodiment variants of an adjustment device 3 according to the invention of FIGS. 1A to 4 provide a solution particularly in this respect.

[0044] What is thus proposed is an adjustment device 3 with a crank shaft 2, which is shown in different views in FIGS. 1A to 10. This crank shaft 2 is constructed in a modular manner with several shaft modules 6.1, 6.2, 6.3, 6.4, 7A and 7B. At that, the rotation of the crank shaft 2 about its longitudinal axis LA is realized by means of an actuator, which is not shown in the present case. This actuator may for example engage in the area of a front or rear axial end of the crank shaft 2. In the present case, the crank shaft 2 comprises different types of shaft modules, namely (a) shaft modules 6.1 to 6.4 that are embodied as holder modules and respectively have a coupling element 20.1 to 20.4 with a fork head 201 for linking a connecting rod 23a to 23c, as well as (b) bearing modules 7A, 7B without a coupling element that are configured to provide a rotatable mounting of the crank shaft 2 at the [bearing blocks] 4A and 4B. For this purpose, the bearing modules 7A and 7B may for example be embodied in a tubular or sleeve-shaped manner and received in a rotatable manner at the respectively associated bearing block 7A or 7B.

[0045] Amongst each other, the individual shaft modules 6.1 to 6.4, 7A, 7B are fixated at each other by means of at least one toothing in the mounted state of the crank shaft 2 according to the intended use as it is shown in FIGS. 1A to 10. However, in principle the individual shaft modules 6.1 to 6.4, 7A, 7B can be fixated in different rotational positions relative to each other about the longitudinal axis LA, so that individual shaft modules 6.1 to 6.4, 7A, 7B can be aligned differently relative to each other, and can subsequently be fixated at each other and connected to each other in a torque-proof manner.

[0046] A tension rod 5 is provided for fixating the individual shaft modules 6.1 to 6.4, 7A and 7B arranged behind each other along the longitudinal axis LA relative to each other and to connect them to each other in a torque-proof manner. This tension rod 5 extends through corresponding passage openings 60H, 70H of the individual shaft modules 6.1 to 6.4, 7A, 7B. The individual shaft modules 6.1 to 6.4, 7A and 7B are axially pre-stressed against one another by means of a head 50 of the tension rod 5, which abuts a holder module 6.4 at a first axial end of the crank shaft 2, and a nut N that is screwed onto the tension rod 5 at the other axial end of the crank shaft 2. In the present case, the nut N acts on a bearing module 7A.

[0047] On the front-face side, each of the shaft modules 6.1 to 6.4, 7A, 7B has respectively one inner toothing 608A, 608B or 78 for the torque-proof toothing of the individual shaft modules 6.1 to 6.4, 7A and 7B amongst each other. Here, the face-side ends of the individual shaft modules 6.1 to 6.4, 7A, 7B respectively have a circular cross section, wherein the respective inner toothing 608A, 608B or 78 is embodied in a circumferential manner at an annular protruding edge at each front face of the respective shaft module 6.1 to 6.4, 7A, 7B. Respectively one externally toothed intermediate piece in the form of a gear wheel ring 8.1, 8.2, 8.3, 8.4 or 8.5, which is assigned to two shaft modules 7A/6.1, 6.1/6.2, 6.2/6.3, 6.3/7B or 7B/6.4, is provided for the torque-proof connection to an adjoining shaft module 6.1 to 6.4, 7A, 7B.

[0048] A likewise circumferential outer toothing 88 is embodied at an outer shell surface at each gear wheel ring 8.1 to 8.5. Respectively protruding in a ring-shaped manner, the internally toothed edges of each shaft module 6.1 to 6.4, 7A, 7B respectively project so far axially that the outer toothing 88 of a gear wheel ring 8.1 to 8.5 can be received between booth adjoining shaft modules and meshes with the inner toothings 608A/608B, 608B/78 or 78/608A of two adjoining shaft modules, so that they are thus connected to each other in a torque-proof manner when a sufficient axial pre-stress is applied to the shaft modules 6.1 to 6.4, 7A, 7B arranged along the longitudinal axis LA via the tension rod 5 and the nut N screwed thereto. At that, each of the intermediate pieces 8.1 to 8.5 has a passage opening 80H for the tension rod 5.

[0049] Through the toothings of the individual shaft modules 6.1 to 6.4, 7A, 7B, a highly stressable form-fit connection and fixation of the individual shaft modules 6.1 to 6.4, 7A, 7B to each other is achieved. At the same time, the individual shaft modules 6.1 to 6.4, 7A, 7B can also easily take different relative positions with respect to each other when an axial pre-stress is reduced or eliminated, and the individual shaft modules have been displaced along the longitudinal axis LA relative to each other, e.g. after the nut N has been screwed on.

[0050] As an additional adjusting possibility, each coupling element 20.1 to 20.4 is provided to be radially adjustable at the holder modules 6.1 to 6.4 of the crank shaft 2. As illustrated by way of example for a holder module 6.3 with a coupling element 20.3 based on FIGS. 2A to 2C and 3, for this purpose each holder module 6.1 to 6.4 is provided with a centrally arranged recess 600, by means of which a carrier body 60 of each holder module 6.1 to 6.4 is divided into two (front and rear) module sections 60A and 60B. These two module sections 60A, 60B are connected to each other via an axially extending attachment section 61 having a circular-segment-shaped cross section. A part of each module section 60A, 60B is the respective internally toothed edge projecting at the front-face side for the torque-proof connection to the adjoining shaft module 6.1 to 6.4, 7A, 7B by means of the associated gear wheel ring 8.1 to 8.5.

[0051] Inner walls of the recess 600 that are positioned opposite each other along the longitudinal axis LA and are formed by both module sections 60A and 60B, respectively have a toothed toothing surface 601 or 602 on their entire surface, interrupted only by a part of the passage opening 60H for the tension rod 5. Respectively one toothed toothing surface 2001, 2002 of a fastening body 200 of the associated coupling element 20.1-20.4 can be brought into a form-fit mesh with these opposite toothing surfaces 601, 602 to fixate the respective coupling element 20.1 to 20.4 in a prescribed radial position.

[0052] When the crank shaft 2 is mounted according to the intended use, the fastening body 200 of each coupling element 20.1 to 20.4, which in the present case extends longitudinally and has a rectangular cross section, abuts the associated (counterpart) toothing surfaces in a locking manner via its toothing surfaces 2001 and 2002 that are facing away from one another. At that, the axial pre-stress applied via the tension rod 5 supports the meshing of the respective toothing surfaces 601/2001 and 602/2002 of the fastening body 200, on the one hand, and of the associated shaft module 6.1, 6.2, 6.3 or 6.4, on the other.

[0053] For (additionally) fixating a coupling element 20.1, 20.2, 20.3 or 20.4 at a holder module 6.1, 6.2, 6.3 or 6.4, each fastening body 200 of a coupling element 20.1 to 20.4 is provided with two oblong holes 2003 that are embodied to be longitudinally extending in the radial direction and arranged opposite each other at two walls of the fastening body 200. An attachment element in the form of a threaded bolt S is passed through the two oblong holes 2003 substantially perpendicular to the longitudinal axis LA. With its head, this threaded bolt S abuts at the attachment section 61 of the respective holding module 6.1 to 6.4, and with its shaft extends through a passage opening 61H in the attachment section 61 as well as further through the opposite oblong holes 2003 of the fastening body 200. A nut is screwed on at an end of the threaded bolt S projecting from the fastening body 200 to additionally apply a holding force perpendicular to the longitudinal axis LA for fixating a coupling element 20.1 to 20.4 in an occupied radial adjusting position.

[0054] Consequently, for modifying the radial position of the fork heads 201 of a coupling element 20.1 to 20.4, the axial pre-stress that is applied via the tension rod 5 is reduced by screwing on the nut N at the end of the tension rod 5. What is further facilitated by detaching the nut of the threaded bolt S at the respective holder module 6.1 to 6.4 is an adjustment of the respective fastening body 200 and of the fork head 201 embodied in one piece with the same relative to the carrier body 60 of the holder module 6.1 to 6.4. Here, the different adjusting positions to be occupied, are predetermined by the meshing teeth of the different toothing surfaces 601/2001 and 2002/602.

[0055] To be able to adjust the coupling element 20.1-20.4 relative to the respective carrier body 60 as well as radially to the tension rod 5, the fastening body 200 of at each of the toothing surfaces 2001 and 2002 has a radially extending continuous oblong hole 2001H or 2002H through which the tension rod 5 extends.

[0056] The embodiment variant of a crank shaft 2 for an adjustment device 3 according to the invention that is shown in FIGS. 1A to 1C, 2A to 2C and 3 is variable in two aspects when it comes to setting a transmission and adjustment track ratio of the individual guide vanes 111 of different guide vane rows 13a to 13c that are to be adjusted by the rotation of the crank shaft 2. On the one hand, the individual shaft modules 6.1 to 6.4, 7A, 7B can be fixated in different rotational positions relative to each other to thus be able to vary the orientation and angular position of the coupling elements 20.1 to 20.4, which are provided at individual holder modules 6.1 to 6.4 and at which the connecting rods 32a, 32b, 32c coupled to the adjusting rings 30a, 30b and 30c are hinged, relative to each other. On the other hand, where necessary, also each coupling element 20.1 to 20.4 including the fork head 201 provided for linking is adjustable in the radial direction with respect to the longitudinal axis LA of the crank shaft 2, and thus the length with which a fork head 201 of a coupling element 20.1 to 20.4 radially projects with respect to the longitudinal axis LA is variable. At the same time, a highly stressable form-fit connection of the individual components of the crank shaft 2 to each other is ensured via the respective fixation by means of one or several toothings in the mounted state of the crank shaft 2 according to the intended use.

[0057] FIG. 4 illustrates a further embodiment variant for the torque-proof, but releasable connection of two shaft modules 9.1, 9.2 of a modular crank shaft 2 for an adjustment device 3 according to the invention. The shaft modules 9.1, 9.2 that are shown here are embodied integrally and thus in one piece with the coupling elements 92.1 and 92.2 at which the linking of the respective connecting rod 30a to 30c occurs. Here, the coupling elements 92.1 and 92.2 respectively project radially from a base body 90 of a shaft module 9.1 or 9.2.

[0058] Each shaft module 9.1, 9.2 further has a passage opening 90H for the tension rod 5. In the present case, the axial pre-stress that is applied by the tension rod 5 is also used for securing an alternating form-fit toothing mesh to fixate the two shaft modules 9.1 and 9.2 to each other in a torque-proof manner in the mounted state of the crank shaft 2 according to the intended use. In the present case, a Hirth toothing 98A, 98B is provided. A corresponding annular circumferential toothing surface for the respective Hirth toothing 98A or 98B is embodied at both axial front faces of each shaft module 9.1,9.2.

PARTS LIST

[0059] 1 housing [0060] 10 bearing extension [0061] 11 low-pressure compressor [0062] 110 rotor blade [0063] 111 guide vane [0064] 111a bearing journal [0065] 111b journal end [0066] 114 shell surface [0067] 12 high-pressure compressor [0068] 12a-12d rotor blade row [0069] 13 high-pressure turbine [0070] 13a-13c guide vane row [0071] 15 medium-pressure turbine [0072] 15 low-pressure turbine [0073] 2 crank shaft [0074] 20.1-20.4 coupling element [0075] 200 fastening body [0076] 2001, 2002 toothing surface [0077] 2001H, 2002H oblong hole/passage opening [0078] 2003 oblong hole/passage opening [0079] 201 fork head [0080] 3 (guide vane) adjustment device [0081] 30a, 30b, 30c adjusting ring (adjusting element) [0082] 31 adjustment lever [0083] 32a, 32b, 32c connecting rod (connection element) [0084] 4A, 4B bearing block [0085] 5 tension rod [0086] 50 head [0087] 6.1-6.4 holder module (shaft module) [0088] 60 carrier body [0089] 600 recess [0090] 601, 602 toothing surface [0091] 608A, 608B inner toothing [0092] 60A, 60B module section [0093] 60H passage opening [0094] 61 attachment section [0095] 61H passage opening [0096] 70H passage opening [0097] 78 inner toothing [0098] 7A, 7B bearing module (shaft module) [0099] 8.1-8.5 gear wheel ring (intermediate piece) [0100] 80H passage opening [0101] 88 outer toothing [0102] 9.1, 9.2 shaft module [0103] 90H passage opening [0104] 92.1, 92.2 coupling element [0105] 98A, 98B Hirth toothing [0106] A outlet [0107] B bypass channel [0108] BK combustion chamber section [0109] D rotational axis/spindle axis [0110] E inlet/intake [0111] F fan [0112] L guide vane assembly [0113] LA longitudinal axis [0114] M central axis/rotational axis [0115] N nut [0116] R entry direction [0117] S threaded bolt (attachment element) [0118] T gas turbine engine [0119] TT turbine [0120] U circumferential direction [0121] V compressor