Modularization of aircraft turbine engine by means of axial and rotational locking means and corresponding installation method

Abstract

The invention relates to a turbine engine comprising:-a first module comprising a decelerator (3) having an input shaft (12); -a second module comprising a low pressure compressor connected to the first module; -a third module comprising a low-pressure shaft centered on the longitudinal axis X and comprising an upstream end connected to the input shaft; and-locking means configured to axially secure the second module relative to the first module and the second module, the locking means comprising:-a first nut (60) screwed onto the thread of the low-pressure shaft and in contact with the annular projection of the second module; -an anti-displacement member (65) configured to axially lock the first nut; -a second nut (73) screwed onto the thread of the second module and configured to axially secure the anti-displacement member; and-a third nut (93), the third nut being screwed onto the anti-displacement member.

Description

Technical Field

[0001] The invention relates to a solution for facilitating the modularization of aircraft turbine engines. Background Art

[0002] Prior art includes documents FR-A1-3115822, FR-A1-2896827 and FR-A1-3013388.

[0003] Aircraft turbine engines are usually constructed as an assembly of modules, each of which may include a fixed part and a movable part. A module is defined as a subassembly of the engine which has sufficiently precise geometric features at its interface with the adjacent modules to enable it to be delivered independently and which, when it includes a rotating part, has undergone individual balancing. The assembly of modules enables the construction of a complete engine, reducing the balancing and matching operations of the interface parts to a minimum.

[0004] The modularity of a turbine engine is a key element in maintaining a turbine engine. In fact, during intervention, parts must be easily accessible without having to disassemble a large number of engine parts. In practice, a turbine engine is constructed so that the turbine engine can be divided into a main module and a secondary module. For example, for a turbine engine with an upstream fan (the terms "upstream" and "downstream" are used relative to the gas flow in the turbine engine), it is configured with three main modules: an upstream main module for the front part including the fan, an intermediate main module for the middle part including the low-pressure compressor and the high-pressure body, and a downstream main module for the rear part including the low-pressure turbine and the low-pressure shaft. In this particular example, the low-pressure body is divided into two modules.

[0005] The low-pressure body can also be divided into three modules, wherein the low-pressure compressor is arranged independently from the rest of the middle main module.

[0006] Maintenance is particularly difficult on a turbine engine comprising a reducer and possibly a system for changing the pitch of the upstream blades. The reducer is attached to an upstream module or an intermediate main module. The reducer comprises an input shaft connected to the rotor of the low-pressure compressor and to the rotor of the low-pressure turbine. In particular, the upstream module and the intermediate main module and the downstream main module, which comprise the components of the low-pressure body, are attached to each other by means of a nut centered on the axis of the turbine engine and used to axially tighten the input shaft and the low-pressure shaft of the reducer.

[0007] During maintenance operations on the reducer or other components of the turbine engine of one of the above-mentioned modules, this nut must be unscrewed from upstream using a tool inserted into the turbine engine along its longitudinal axis. This leaves the downstream main module unfixed. However, this is not enough to completely free the input shaft, since the input shaft is also connected to the rotor of the low-pressure compressor by means of a journal that is attached to the input shaft and must also be disassembled. The rotor of the low-pressure compressor of the intermediate main module also includes a bearing, the inner ring of which is attached to the input shaft.

[0008] The problem in this case is therefore the number of parts that need to be disassembled in order to remove the components (in particular the input shaft) from one of the modules. Generally, it is not possible to disassemble the reducer without disassembling a large part of the turbine engine (including the upstream module, the intermediate main module and the downstream main module).

[0009] The present invention provides a solution to at least some of the above-mentioned problems, which solution simplifies the modularization of an aircraft turbine engine without compromising the performance of the turbine engine. Summary of the invention

[0010] According to the invention, this is achieved by means of a turbine engine, in particular for an aircraft, having a longitudinal axis and comprising:

[0011] - a first module, the first module comprising a reducer, the reducer comprising an input shaft centered on a longitudinal axis,

[0012] - a second module, the second module comprising a low-pressure compressor, the second module being connected to the first module,

[0013] a third module comprising a low-pressure shaft centered on the longitudinal axis, the low-pressure shaft comprising an upstream end connected to the input shaft, and

[0014] - a locking device configured to axially fix the third module relative to the first module,

[0015] The locking device is configured to axially fix the second module relative to the first module and the third module, and the locking device comprises:

[0016] a first nut which is screwed onto the thread of the upstream end of the low-pressure shaft and which comes into contact with the annular protrusion on the second module,

[0017] an anti-displacement member configured to axially limit the displacement of the first nut,

[0018] a second nut which is screwed onto the thread of the second module and is configured to axially fix the anti-displacement member, and

[0019] - a third nut which is screwed onto the anti-displacement member.

[0020] This solution therefore makes it possible to achieve the above-mentioned objectives. As a result, the modules of the low-pressure turbine and the low-pressure compressor can be disassembled with a reduced number of operations compared to other modules, and without the need to disassemble other adjacent modules. This applies in particular to the input shaft, which is subject to great stress and can now be inspected and replaced quickly and easily. The input shaft can be disassembled independently of the other shafts using a locking device, which includes a plurality of nuts and components that are tightened / engaged with each other to perform anti-rotation and anti-displacement functions or axial locking. In addition, this construction provides greater modularity and saves time when inspecting parts and disassembling some of them independently. This modularity is part of the drive to reduce environmental impact, as it means that only the necessary components can be repaired and inspected, thereby reducing the downtime of the turbine engine.

[0021] The turbine engine according to the invention may include one or more of the following features, taken in isolation from one another or in combination with one another:

[0022] The locking device comprises a locking element cooperating with the first nut and the third nut.

[0023] - The first nut is mounted so as to rotate freely about the longitudinal axis.

[0024] The second module comprises a low-pressure compressor shaft connected to the low-pressure compressor and centered on the longitudinal axis, the low-pressure compressor shaft being connected to the input shaft and the low-pressure shaft.

[0025] The low-pressure compressor shaft comprises an annular protrusion, and the first nut comprises a downstream face in contact with an upstream face of the annular protrusion.

[0026] The anti-displacement member comprises a plurality of teeth, each tooth being configured to engage in a recess in the low-pressure compressor shaft.

[0027] - The outer diameter of the plurality of teeth is greater than the outer diameter of the collar of the first nut.

[0028] The second nut is configured to be locked against rotation by the first locking system.

[0029] -The first locking system includes:

[0030] a first ring element, the first ring element being centered on the longitudinal axis and being configured to come into contact with the radial annular surface of the second nut, the first ring element comprising a plurality of radial teeth, each radial tooth being configured to engage in a radial recess of the low-pressure compressor shaft, and

[0031] - a second ring element, centered on the longitudinal axis and received in an annular groove of the second nut, the annular groove being arranged upstream of the radial annular surface.

[0032] The turbine engine comprises a second locking system configured to enclose the third nut in the annular cavity of the input shaft.

[0033] The third nut is configured to be locked against upstream translation by at least the second locking system.

[0034] - The second locking system includes:

[0035] a third ring element centered on the longitudinal axis and comprising a plurality of radial teeth having a downstream face configured to contact the annular face of the input shaft, the third ring element comprising an upstream face, the downstream face of the third nut abutting against the upstream face of the third ring element, and

[0036] - a fourth ring element, centered on the longitudinal axis and received in an annular groove of the input shaft, the fourth ring element facing the downstream face of the radial teeth.

[0037] The first module comprises a fan connected to a fan shaft and arranged upstream of the second module, the low-pressure shaft driving the fan shaft in rotation by means of a speed reducer.

[0038] -The fan is a ducted fan.

[0039] -The reducer is located in a lubricated enclosure.

[0040] -The low pressure compressor shaft is independent of the input shaft and the low pressure shaft.

[0041] The low-pressure shaft comprises an upstream end extending inside the low-pressure compressor shaft, and the first nut, the second nut and the third nut are mounted inside the low-pressure compressor shaft.

[0042] - A low-pressure compressor shaft is connected to the upstream end of the low-pressure shaft and to the downstream end of the input shaft.

[0043] -The low-pressure compressor shaft is connected to the rotor of the low-pressure compressor.

[0044] The low-pressure compressor shaft is connected to the rotor of the low-pressure compressor by means of journals which are fixed to the rotor of the low-pressure compressor and to the low-pressure compressor shaft.

[0045] The journal is formed as a single piece with the low-pressure compressor shaft.

[0046] - The third module comprises a low-pressure turbine connected to a low-pressure shaft, the low-pressure shaft comprising a downstream end connected to a low-pressure turbine rotor.

[0047] - The inner diameter of the input shaft of the reducer is smaller than the inner diameter of the low-pressure compressor shaft.

[0048] The internal diameter of the input shaft of the reducer is greater than the internal diameter of the downstream end of the low-pressure compressor shaft.

[0049] The first nut comprises a thread which is screwed onto the third module.

[0050] The radial recess of the low-pressure compressor shaft extends radially outwards from the second nut.

[0051] The locking device is configured to fix the low-pressure shaft relative to the low-pressure compressor shaft, to fix the input shaft relative to the low-pressure compressor shaft, and to fix the input shaft relative to the low-pressure shaft.

[0052] The invention also relates to an aircraft comprising at least one turbine engine as described above.

[0053] The invention also relates to a method for installing a turbine engine as described above, said method comprising the following steps:

[0054] - Screw the first nut onto the low pressure shaft,

[0055] - limiting the translation of the first nut along the longitudinal axis on the low-pressure compressor shaft by means of an anti-displacement member,

[0056] - axially fixing the anti-displacement member by means of the second nut, and

[0057] - Screw the third nut onto the anti-displacement member.

[0058] According to a feature of the method, the method comprises the step of engaging a locking element on the third nut and on the first nut. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Other features and advantages of the present invention will become apparent from the following detailed description. To understand other features and advantages of the present invention, reference is made to the accompanying drawings, in which:

[0060] Figure 1 is a schematic half view of an axial cross section of an aircraft turbine engine;

[0061] Figure 2 According to the present invention Figure 1 Detailed view of

[0062] Figure 3 is a perspective view showing the shaft of one of the modules of a turbine engine according to the invention;

[0063] Figure 4 is a perspective view of a shaft, wherein a first nut is installed following the steps of the installation method according to the present invention;

[0064] Figure 5is a perspective view of a shaft in which an anti-displacement member for a first nut is installed following the steps in the installation method according to the present invention;

[0065] Figure 6 According to the present invention Figure 5 Detailed view of

[0066] Figure 7 is a perspective view, substantially along a longitudinal sectional plane, of a shaft, wherein a second nut and a locking system for the nut are installed following the steps of the installation method according to the invention;

[0067] Figure 8 The first locking system for locking the rotation of the second nut according to the present invention is shown in more detail;

[0068] Fig. 9 yes Figure 7 a detailed view of a substantially radial cross-sectional plane of the shaft, wherein a second nut according to the invention is mounted;

[0069] Fig.10 is a perspective view of a shaft, wherein a third nut is installed following the steps in the installation method according to the present invention;

[0070] Fig.11 is a perspective view of a shaft in which a locking system is installed following the steps of the installation method according to the present invention;

[0071] Fig.12 A third nut according to the invention is shown in more detail;

[0072] Fig.13 yes Fig.11 perspective views of steps in the illustrated installation method;

[0073] Fig.14 is a perspective view of a shaft in which a locking system is installed following the steps of the installation method according to the present invention;

[0074] Fig.15 is a perspective view of two shafts being assembled together following the steps in the installation method according to the present invention; and

[0075] Fig.16 is a perspective view of locking the translation and rotation of a shaft using a locking device following the steps in the installation method according to the present invention. DETAILED DESCRIPTION

[0076] The present invention is applicable to Figure 1An aircraft turbine engine 1 is shown which is a turbojet engine equipped with a ducted fan 2 and a speed reducer 3. Of course, the invention is not limited to turbojet engines and can be applied to any type of turbine engine, in particular a turbine engine equipped with a speed reducer.

[0077] The turbine engine 1 extends along a longitudinal axis X, which is usually the axis of rotation of the rotor of the turbine engine. The turbine engine 1 comprises, from upstream to downstream along the longitudinal axis X and the gas flow, a fan 2, a low-pressure compressor 4, a high-pressure compressor 5, an annular combustion chamber 6, a high-pressure turbine 7 and a low-pressure turbine 8.

[0078] The low-pressure compressor 4 and the low-pressure turbine 7 are mechanically connected by a low-pressure shaft 9 to form a low-pressure body. The high-pressure compressor 5 and the high-pressure turbine 8 are mechanically connected by a high-pressure shaft 10 to form a high-pressure body. The low-pressure shaft 9 extends at least partially inside the high-pressure shaft 10 and is coaxial with the high-pressure shaft.

[0079] The turbine engine 1 is configured with a plurality of modules assembled / associated with each other, making the turbine engine easier to maintain. Shafts and / or interfaces are used to make these connections.

[0080] The first module 11 comprises a fan 2 and a reducer 3 . Advantageously, the reducer comprises an input shaft 12 centered on the longitudinal axis X. Advantageously, the input shaft 12 forms part of the first module 11 .

[0081] The fan 2 comprises a fan shaft 13 which is advantageously driven in rotation by the low-pressure shaft 9 via the speed reducer 3 .

[0082] The second module 14 comprises the low-pressure compressor 4. The second module 14 further comprises a low-pressure compressor shaft 15, to which the low-pressure compressor 4 is connected. The low-pressure compressor shaft 15 is centred on a longitudinal axis X.

[0083] The third module 16 comprises a low-pressure turbine 7 and a low-pressure shaft 9 centered on the longitudinal axis X. Advantageously, the low-pressure shaft 9 comprises an upstream end 9a connected to the rotor of the low-pressure compressor, and a downstream end 9b connected to the rotor of the low-pressure turbine. The upstream end 9a is connected to the input shaft 12 of the reducer 3.

[0084] The fourth module 17 comprises the high-pressure compressor 5 .

[0085] Advantageously, the fourth module 17 comprises a high-pressure turbine 7 . The fourth module 17 also comprises an annular combustion chamber 6 axially interposed between the high-pressure compressor 5 and the high-pressure turbine 7 .

[0086] In this configuration, the low-pressure body of the turbine engine 1 is divided into three modules. Alternatively, the low-pressure body is divided into two modules, wherein the low-pressure compressor forms part of the second module.

[0087] The speed reducer 3 (indicated by its acronym "RGB") includes an epicyclic gear train. Of course, the speed reducer may include a planetary gear.

[0088] The reducer 3 generally includes a sun gear 20 (or internal planetary gear), a plurality of planetary gears 21 (which are pinions), a planet carrier 22, and an outer gear ring 23 (or external planetary gear). The sun gear 20 is centered on the longitudinal axis X. The outer gear ring 23 is centered on the longitudinal axis X and extends around the sun gear 20. The planetary gears 21 are located between the sun gear 20 and the outer gear ring 23 and are carried by the planet carrier 22. The planetary gears 21 are respectively installed so that they can freely rotate around the planetary gear axis by means of bearings, and mesh with the external teeth on the sun gear 20 and the internal teeth on the outer gear ring 23.

[0089] In this case, the outer ring gear 23 is fixed and attached to the stator of the turbine engine, which in this case is the inlet housing 24. The sun gear 20 is rotatably movable and coupled to the input shaft 12, which in turn is connected to the low-pressure shaft 9. The planet carrier 22 is also rotatably movable and coupled to the fan shaft 13. Therefore, the fan 2 is driven in rotation by the low-pressure shaft 9 by means of the reducer 3.

[0090] In the case of a planetary gear reducer, the outer ring gear is rotationally fixed to the fan shaft and the planet carrier is fixed to a stationary structure such as the inlet housing 24 .

[0091] Advantageously, Figure 1 The reducer 3 in the embodiment of the present invention is arranged in a lubricating enclosure 25 extending around the longitudinal axis X. Therefore, the shape of the enclosure 25 is generally annular. The enclosure 25 is bounded at its inner periphery by the fan shaft 13 and the input shaft 12. Advantageously, but not exclusively, the lubricating enclosure 25 is bounded at its outer periphery by an inlet housing 24 extending around the reducer 3. The enclosure 25 is bounded upstream by a first annular bearing support 26. The first bearing support 26, for example, comprises an outer end attached to the inlet housing 24, and an inner end of an outer race holding two rolling bearings 27.

[0092] Advantageously, rolling bearings 27 comprise an inner ring attached to the fan shaft 13. These bearings make it possible to guide at least the fan shaft 13 in rotation. One of the upstream bearings closest to the reducer 3 also helps to guide the planet carrier in rotation in a more stable manner. The bearing closest to the reducer is optional.

[0093] Finally, the enclosure 25 is delimited downstream by, for example, a second annular bearing support 28. The second bearing support 28 comprises an outer end 28a attached to the inlet housing 24, and an inner end 28b holding the outer rings of two rolling bearings 29.

[0094] Advantageously, two downstream rolling bearings 29 enable the input shaft of the reducer and the low-pressure compressor shaft (which is fixed to the input shaft) to be guided.

[0095] In this example, the rolling bearing 29 comprises an inner ring attached to the low-pressure compressor shaft 15. The second bearing support 28 comprises an annular shell 30, a first end 30a of which is attached to the second bearing support 28 and a second end 30b of which cooperates with a sealing element 31 mounted around the low-pressure compressor shaft 15.

[0096] refer to Figure 1 , the enclosure 25 also includes sealing means for sealing the enclosure 25. These sealing means include a first removable cover 32 configured to seal the enclosure 25 upstream, and a second removable cover 33 configured to seal the enclosure downstream. The first cover 32 is mounted inside the fan shaft 13 and close to the reducer 3 along the longitudinal axis. The second cover 33 is mounted inside the input shaft 12, at the downstream end 12b of the input shaft. The second cover 33 is mounted downstream of the reducer 3 (more precisely, downstream of the flexible device).

[0097] Advantageously, both the low-pressure compressor shaft 15 and the input shaft 12 are hollow. The low-pressure shaft 9 is also hollow.

[0098] The turbine engine 1 further includes an intermediate casing 34 inserted between the low-pressure compressor 4 and the high-pressure compressor 5 , an inter-turbine casing 35 inserted between the high-pressure turbine 7 and the low-pressure turbine 8 , and an exhaust casing 36 located downstream of the low-pressure turbine 8 .

[0099] exist Figure 2 In the embodiment, the components of the shafts of the turbine engine are connected to each other and locked in place relative to each other. The components include a first shaft and a second shaft. In this example, the first shaft is the input shaft 12. The second shaft is the low-pressure compressor shaft 15. The shaft assembly also includes a third shaft as the low-pressure shaft 9.

[0100] The first coupling device 40 is configured to (removably) connect the first module 11 and the second module 14. The second coupling device 41 is configured to (removably) connect the second module 11 and the third module 15.

[0101] The turbine engine comprises locking means 42 configured to connect the modules together and to axially fix the modules together. More specifically, the locking means are configured to axially fix the second module relative to the first module and the third module.

[0102] The low pressure compressor shaft 15 is connected to the low pressure compressor rotor by means of a journal 43. In particular, the second module 14 comprises (in addition to the low pressure compressor) a journal 43 rotationally fixed to the rotor of the low pressure compressor and the low pressure compressor shaft 15. The low pressure compressor shaft 15 is connected to the input shaft 12.

[0103] like Figure 3 As shown, the low-pressure compressor shaft 15 comprises a generally straight cylindrical shape having an axis A. Advantageously, the low-pressure compressor shaft extends between an upstream end 15a and a downstream end 15b. An annular journal 43 extends radially from the outer surface of the low-pressure compressor shaft 15 at a first end 43a. The journal 43 comprises a second end 43b, which is fixed to the rotor via an attachment member such as a threaded rod (screw) and a nut. In the example shown, the journal 43 is formed as an integral piece with the low-pressure compressor shaft 15. Alternatively, the journal 43 is an insert, and the inner end 43a of the journal is attached and axially fixed to the downstream end 15b of the low-pressure compressor shaft 15.

[0104] Advantageously, the low-pressure compressor shaft 15 comprises an annular bearing surface 44 rising radially from its outer surface. The inner ring 29a of one of the bearings 29 is in axial contact with this annular bearing surface 44.

[0105] The low-pressure compressor shaft 15 comprises an external thread 45 configured to engage with an internal thread of a bearing nut 46 axially locking the inner ring 29a. The external thread 45 is arranged towards the upstream end 15a of the low-pressure compressor shaft 15.

[0106] As previously mentioned, the low-pressure compressor shaft 15 is connected to the input shaft 12. The low-pressure compressor shaft 15 is coupled to the input shaft 12 via a spline to transmit rotational torque. Figure 2 As shown, the first coupling device 40 includes first internal splines 47 formed on an inner surface 48 of the low-pressure compressor shaft 15. The first internal splines 47 are oriented along the axis A (and along the longitudinal axis) and are regularly arranged around the axis A. The first internal splines 47 are configured to engage with corresponding first external splines 49 of the input shaft 12. Advantageously, the first internal splines 47 are located close to (but not limited to) the upstream end 15a of the shaft 15.

[0107] The low-pressure compressor shaft 15 comprises second internal splines 50 formed on the inner surface 48. These second internal splines 50 are oriented along the axis A and are evenly distributed around this axis A. Advantageously, these second internal splines are situated at the downstream end 15b of the low-pressure compressor shaft.

[0108] In the example shown, the low pressure compressor shaft 15 comprises a first shaft section 15aa, a second shaft section 15ab and a third shaft section 15ac. The inner diameter D1 of the first section 15aa is greater than the inner diameter D2 of the second section 15ab. The inner diameter D2 of the second section 15ab is greater than the inner diameter D3 of the third section 15ac.

[0109] Advantageously but not limited to, the low-pressure compressor shaft 15 includes an annular protrusion 51 extending radially inwardly from the low-pressure compressor shaft. The annular protrusion 51 is arranged between the first shaft section 15aa and the third shaft section 15ac. More specifically, the annular protrusion 51 is arranged between the second section 15ab and the third section 15ac. In this example, the annular protrusion 51 is formed upstream of the spline 50.

[0110] The low-pressure compressor shaft 15 further comprises an annular shoulder 52 extending radially inwardly from the low-pressure compressor shaft. The shoulder 52 is arranged between the first shaft section 15aa and the third shaft section 15ac. More specifically, the annular shoulder 52 is arranged along the longitudinal axis X upstream of the annular protrusion 51.

[0111] exist Figure 2 and Figure 3 , the downstream end 12b of the input shaft 12 extends inside the low-pressure compressor shaft 15. Corresponding first external splines 49 are formed on the outer surface of the input shaft 12. The first external splines 49 are located at the downstream end 12b of the shaft 12. The shaft 12 has an outer diameter at the downstream end 12b, which is advantageously substantially smaller than the inner diameter D1 of the first section 15aa of the low-pressure compressor shaft 15.

[0112] The input shaft 12 also has an outer diameter D4 at the reducer 3, which is advantageously smaller than the outer diameter of the downstream end 12b of the input shaft. The efficiency of the turbine engine also depends on the radial overall size of the reducer, and the diameter of the input shaft 12 must be small so that the ratio of the diameter of the outer ring gear to the diameter of the sun gear is close to 1.

[0113] Advantageously, the diameter D4 of the input shaft 12 is between the following radii:

[0114] - a radius sufficient to transmit the rotational torque,

[0115] a radius sufficient to allow an external tool (described later) to pass inside the input shaft 12,

[0116] - a radius as small as possible to save weight, and

[0117] - A radius that is as low as possible to accommodate the height of the flexible elements (the height of these elements determines the flexibility of the part).

[0118] Advantageously, the reduction ratio of the reducer is between 2.5 and 7. The diameter of the input shaft 12 must be small enough to achieve the desired reduction ratio, but large enough to accommodate torque and tools. The ratio between the diameter of the ring gear and the diameter of the input shaft 12 must be the reduction ratio -1 (Willis formula for the reduction ratio between the ring gear and the sun gear in the reference frame of the planet carrier).

[0119] The input shaft 12 has sufficient flexibility to avoid hyperstatics in the reducer 3. Advantageously but without limitation, the input shaft 12 comprises a bellows which together with the splines allow such flexibility to be achieved. In this way, misalignment between the input shaft 12 and the low-pressure compressor shaft 15 may occur, which is particularly advantageous in the case of relatively long engines.

[0120] exist Figure 1 In the embodiment of the present invention, the low-pressure compressor shaft 15 is rotationally fixed to the low-pressure shaft 9. Advantageously, the low-pressure compressor shaft 15 is coupled to the low-pressure shaft 9 by means of a spline to transmit a rotational torque. Advantageously, the second coupling device 41 is formed by a spline. In particular, the upstream end 9a of the low-pressure shaft 9 extends inside the low-pressure compressor shaft 15. The low-pressure shaft 9 includes a second external spline 53, which corresponds to and engages with the second internal spline 50 of the low-pressure compressor shaft 15. The second external spline 53 is arranged on the outer surface of the low-pressure shaft 9 and faces the upstream end of the low-pressure shaft. The outer diameter of the low-pressure shaft 9 (at the upstream end 9a of the low-pressure shaft) is substantially smaller than the diameter of the third section 15ac of the low-pressure compressor shaft 15.

[0121] The locking device 42 is configured to fix the low-pressure shaft 9 relative to the low-pressure compressor shaft 15 , to fix the input shaft 12 relative to the low-pressure compressor shaft 15 , and to fix the input shaft 12 relative to the low-pressure shaft 9 .

[0122] refer to Figure 4 , the locking device 42 comprises a first nut 60 configured to at least partially axially lock the low-pressure shaft 9 relative to the low-pressure compressor shaft 15. Advantageously, the first nut 60 is screwed onto a thread on the upstream end 9a of the low-pressure shaft 9 and comes into contact with the annular protrusion 51 on the second module 14. The first nut 60 is configured to axially fix the low-pressure shaft 9 relative to the low-pressure compressor shaft 15 and to withstand the axial thrust of the low-pressure turbine.

[0123] Advantageously, the first nut 60 comprises a cylindrical body 61 having an axis of revolution B. The first nut 60 comprises a collar 62 extending radially outwards from one end of the cylindrical body 61. In this example, the first nut 60 comprises an L-shaped axial cross section.

[0124] The first nut 60 is screwed onto the low-pressure shaft 9 and is centered on the longitudinal axis. Advantageously, the first nut 60 is radially arranged between the low-pressure compressor shaft 15 and the low-pressure shaft 9. More specifically, the first nut 60 comprises an outer thread 63 engaged with an inner thread 64 of the low-pressure shaft 9. The outer thread 63 is supported by the outer surface of the cylindrical body 61. Advantageously, the inner thread 64 is located at the upstream end 9a of the low-pressure shaft 9.

[0125] In this example, the outer diameter of the nut 60 at the cylindrical body 61 is smaller than the inner diameter of the low-pressure shaft 9. It can be seen that the inner diameter of the nut is smaller than the inner diameter of the input shaft 12 (see Figure 2 ).

[0126] The collar 62 of the first nut 60 comprises an annular face configured to come into contact with an annular surface complementary to the annular protuberance 51. In particular and advantageously, the annular face is the downstream annular face 62b and the complementary annular surface is the complementary upstream annular surface 51a.

[0127] refer to Figure 5 and Figure 6 The locking device 42 includes an anti-displacement member 65, which is configured to "lower" the attachment device (here is a thread) and realize the assembly between the input shaft 12 and the third nut 90 described later (in particular, the engagement of the internal thread 72 of the cylindrical body 66 of the anti-displacement member 65 with the external thread 95 of the cylindrical body 90a of the third nut 90).

[0128] Advantageously, the collar 62 is arranged between the anti-displacement member 65 and the annular projection 51 .

[0129] Advantageously, the first nut 60 is mounted to rotate freely in the low-pressure compressor shaft 9, which will be explained below. There are some axial and radial clearances between the other parts. When the various components are loosened, the first nut 60 can move axially and rotate freely in a short space. When the various components are tightened, the first rotation locking system 77 abuts against the anti-displacement member 65. The anti-displacement member enables the first nut to move axially (depending on the size of the clearance provided). The first nut 60 faces and / or abuts against the annular protrusion 51 on the compressor shaft 15.

[0130] Advantageously, the anti-displacement member 65 comprises a cylindrical body 66 having an axis of revolution C. When mounted, the anti-displacement member 65 is centered on the axis X. Advantageously, the anti-displacement member 65 comprises an annular wing 67 extending radially outwards from one end of the cylindrical body 66. A plurality of teeth 68 extend from a downstream face 67 b of the annular wing 67 along the axis of revolution C. In particular, the teeth 68 are positioned close to an outer peripheral edge 69 of the annular wing 67. The downstream face 67 b faces the upstream annular face 62 a of the collar 67 of the first nut 60.

[0131] Advantageously, at least one axial gap J1 is provided between the downstream face 67 b and the upstream annular face 62 a , such that the first nut 60 can rotate about the longitudinal axis X.

[0132] The anti-displacement member 65 includes teeth 68 (those teeth described above) which are configured to engage in recesses 70 of complementary shape in the second module, respectively. Figure 3 As can be seen in FIG. 1 , the low-pressure compressor shaft 15 comprises a notch 70 oriented along the longitudinal axis. Advantageously, the notch 70 is located upstream of the annular protrusion 51 .

[0133] When installed, the teeth 68 extend radially beyond the annular edge 71 of the collar 62 of the first nut 60. In other words, the outer diameter of the plurality of teeth 68 is greater than the outer diameter of the annular edge 71 of the collar 62.

[0134] The distance L1 measured between the bottom of the recess 70 and the downstream face 67b (when installed along the longitudinal axis X) is greater than the distance L2 measured between the upstream annular surface 51a complementary to the protrusion 51 and the downstream face 67b. In this example, the bottom of the recess 70 is located in the same plane as the complementary upstream annular surface 51a. The difference between the distance L1 and the distance L2 generates an axial clearance J1 which is Figure 6 Indicated in the middle.

[0135] exist Figure 5 , the anti-displacement member 65 includes an internal thread 72 formed on an inner surface of a cylindrical body 66 thereof.

[0136] Advantageously, the outer diameter of the cylindrical body 66 of the anti-displacement member 65 is greater than the outer diameter of the cylindrical body 61 of the first nut 60 .

[0137] refer to Figure 7 , the locking device 42 also includes a second nut 73, which is screwed onto the thread of the second module 14 and is configured to fix the anti-displacement member 65 axially (i.e., along the longitudinal axis X). The second nut 73 includes a cylindrical body, the axis of which is coaxial with the longitudinal axis. Advantageously, the cylindrical body extends between the first annular surface 74a and the second annular surface 74b. The second nut 73 includes an external thread 74, which is formed on the outer surface 75 of the second nut and is configured to engage with the internal thread 76 of the low-pressure compressor shaft 15. The internal thread 76 is arranged at the second shaft section 15ab.

[0138] The outer diameter of the second nut 73 is greater than the outer diameter of the anti-displacement member 65. The inner diameter of the second nut 73 is also greater than the outer diameter of the anti-displacement member 65. A radial space is provided between the second nut 73 and the anti-displacement member 65. The radial space helps to avoid the transfer of parasitic forces and helps to integrate a locking ring (not shown) of the second nut 73. When installed, the second annular surface 74b of the second nut 73 contacts the upstream surface 67a of the annular wing 67.

[0139] like Figure 7 , Figure 8 and Fig. 9 It can also be seen that the second nut 73 is locked against rotation by a first locking system 77. Advantageously, the first rotation locking system 77 comprises a first ring element 78 centered on the longitudinal axis and configured to come into contact with the first annular surface 74a of the second nut 73. A lug 80 extends radially inwardly from the first annular surface 74a of the second nut 73 and away from the first annular surface 74a of the second nut 73.

[0140] Advantageously, each lug 80 extends over an angular sector around the longitudinal axis. The lugs 80 are also spaced apart to form slots 81. In this way, the slots 81 and the lugs 80 alternate around the longitudinal axis.

[0141] The first ring element 78 includes a plurality of radial teeth 82 extending from its peripheral edge (not shown). The radial teeth 82 are evenly distributed around the longitudinal axis X. Each radial tooth 82 is configured to engage in a corresponding radial recess 84 on the low-pressure compressor shaft 15. Advantageously, the radial recess 84 (e.g. Figure 3 The notch 84 is formed at the annular shoulder 52 .

[0142] Each radial tooth 82 is also arranged in a slot 81 in the second nut 73 .

[0143] like Figure 3 It can also be seen in FIG. 8 that the radial recess 84 opens into an annular surface 86 of the low-pressure compressor shaft 15 , centered on the axis X. In this example, the annular surface 86 is advantageously supported by the annular shoulder 52 .

[0144] The first rotation locking system 77 also includes a second ring element 85 centered on the longitudinal axis X. The second ring element 85 is divided in the general manner of a circlip. The second ring element 85 is received in an annular groove 87 in the second nut 76. The annular groove 87 has an orifice oriented toward the longitudinal axis X. Advantageously, the annular groove 87 is located upstream of the first annular face 74b. More precisely, the annular groove 87 is formed in the lug 80. Alternatively, the annular groove 87 is formed by the distance between the first annular face 74a of the second nut and the inner face of the lug. In this way, the second ring element 85 extends upstream of the first ring element 78, and the lug 80 enables the second ring element 85 to be axially locked. Advantageously, the second ring element 85 is in contact with the upstream face of the first ring element 78.

[0145] exist Fig.10 , the locking device 42 includes a third nut 90 configured to be screwed onto the anti-displacement member 65. The third nut 90 is also configured to be axially fixed on the input shaft 12. As shown, advantageously, the third nut 90 is mounted in an annular cavity 91 in the input shaft 12. Advantageously, but not limited to, the annular cavity 91 is delimited along the longitudinal axis by an upstream shoulder 92 and a radial lug 93. The annular cavity 91 is also radially delimited by a wall section of the downstream end 12b of the input shaft 12.

[0146] In this example, the third nut 90 includes a cylindrical body 90a having an axis D, and an annular base plate 94 extending radially from one end of the third nut 90. The third nut 90 includes an external thread 95 configured to engage with an internal thread 96 of the anti-displacement member 65.

[0147] Advantageously, the outer diameter of the cylindrical body 90 a of the third nut 90 is substantially smaller than the inner diameter of the cylindrical body of the anti-displacement member 65 .

[0148] The annular bottom plate 94 includes an outer peripheral edge 97 (see Fig.10 ), the outer peripheral edge 97 defines a diameter smaller than the inner diameter of the downstream end portion 12b of the input shaft 12. The annular bottom plate 94 includes an upstream face 94a and a downstream face 94b that are opposite to each other along the axis D.

[0149] Advantageously, the upstream face 94 a comprises a plurality of protrusions 98 extending along the axis D. These protrusions 98 are configured to engage in recesses of a tightening tool (not shown) that makes it possible to tighten the third nut 90 onto the anti-displacement member 65 .

[0150] Fig.11 , Fig.12 and Fig.13A second locking system 100 is shown, which is configured to enclose the third nut 90 in the annular cavity 91 of the input shaft 12. Advantageously, the third nut 90 is configured to be at least partially axially locked by the second locking system 100. This axial locking occurs in particular when all parts are tightened (screwed, etc.). Advantageously, the second locking system 100 comprises a third ring element 101 having an axis E and centered on the longitudinal axis when installed. The third ring element 101 is used to integrate and enclose the third nut 90 inside the input shaft 12. Advantageously, the third ring element 101 comprises an upstream face 101a and a downstream face 101b, which are connected by an inner peripheral edge 102a and an outer peripheral edge 102b. Advantageously, the third ring element 101 comprises a plurality of radial teeth 103 extending radially outwards from the outer peripheral edge 102b.

[0151] The downstream face 94b of the third nut 90 contacts the upstream face 101a of the third ring element 101. Each radial tooth 103 includes a downstream face 103b configured to contact the annular face (upstream face 93a) of the radial lug 93. The radial lug 93 also includes an annular downstream face 93b axially opposite to the upstream face 93a.

[0152] As previously mentioned and with reference to Fig.10 , the input shaft 12 comprises a radial lug 93 extending radially towards the longitudinal axis X. Advantageously, the radial lug 93 comprises a plurality of radial notches 104 passing through the radial lug 93 on both sides along the longitudinal axis X. Each radial notch 104 has a U-shaped radial cross section. The orifices of the radial notches 104 are oriented towards the longitudinal axis X and open to both sides of the radial lug 93, located on the upstream face 93a and the downstream face 93b.

[0153] The third ring element 101 is inserted from downstream at the downstream end 12b of the input shaft 12. To this end, the radial teeth 103 of the third ring element 101 pass through the radial recesses 104 respectively, so that the third ring element 101 is arranged in the annular cavity 91 of the input shaft 12. The third ring element 101 is pivoted along the longitudinal axis to form a contact between the downstream face 103b and the upstream face 93a of the radial lug 93. When installed, the inner peripheral edge 102a of the third ring element 101 extends radially inside the peripheral annular face 105 (or the free end of the radial lug 93). The downstream face 94b of the bottom plate is configured to contact the upstream face 101a of the third ring element 101.

[0154] refer to Fig.14Advantageously, the second locking system 100 comprises a fourth ring element 107 centered on the longitudinal axis X. The fourth ring element 107 is configured to axially lock the third ring element 101 in the first module, here in particular axially in the input shaft 12. The fourth ring element 107 is substantially split like a circlip. Advantageously, the fourth ring element 107 is received in an annular groove 108 centered on the longitudinal axis in the input shaft 12. The annular groove 108 is located upstream of the upstream face 93a of the radial lug 93. More specifically, the annular groove 108 is formed in the radial lug 93. The annular groove 108 has a U-shaped axial cross section, and the orifice of the annular groove 108 opens into the peripheral annular face 105 of the radial lug 93. Due to the radial recesses formed in the radial lug 93, the radial lug 93 is in the form of a plurality of radial tab sectors, which comprise segments of the annular groove. In this way, the fourth ring element 107 extends downstream of the third ring element 101 and into the radial notch 104. Advantageously, the fourth ring element 107 is arranged opposite the downstream face of the tooth.

[0155] Advantageously, the third ring element 101 comprises means for axially fixing the fourth ring element 107. Advantageously, the third ring element 101 comprises two protrusions 106, each protrusion 106 extending from the downstream face 103b of the radial teeth 103 of the third ring element 101 along the longitudinal axis X. The radial teeth 103 supporting the protrusions 106 face each other. In other words, these radial teeth 103 are diametrically opposed. In this example, each protrusion 106 has an L-shaped axial cross section.

[0156] Advantageously, each protrusion 106 comprises a first section extending axially from the downstream face, and a second section extending from one end of the first section towards the longitudinal axis X. In this way, the second section is at a distance from the downstream face 103b of the radial tooth 103. In the installed state, when the downstream face 103b of some radial teeth 103 is in contact with the downstream face 93a, the protrusion 106 engages in the corresponding radial recess 104, and the fourth ring element 107 is received in the space formed between the downstream face of the radial tooth 103 and the upstream face of the second section of the protrusion 106. Advantageously, but not limited to, the protrusion 106 engages in the corresponding recess after the third ring element 101 is rotated.

[0157] Advantageously, the locking device 42 comprises a locking element 110 configured to secure in place the first nut 60 and the third nut 90. Advantageously, but not limitingly, the locking element 110 engages with the first nut 60 and the second nut 73. More specifically, the locking element 110 comprises a cylindrical shape centered on a longitudinal axis and having an axis of rotation.

[0158] The locking element 110 comprises first external splines 111 which engage with internal splines 112 of the first nut 60. The first external splines 111 extend respectively along the axis of revolution of the locking element 110 and are evenly distributed around the axis of revolution.

[0159] In another advantageous feature, the locking element 110 further comprises second external splines 113 engaging with internal splines 114 of the third nut 90. The locking element 110 extends inside the low-pressure compressor shaft 15. The second external splines 113 extend respectively along the axis of rotation of the locking element 110 and are evenly distributed around the axis of rotation.

[0160] Advantageously, but not exclusively, the first external splines 111 and the second external splines 113 are axially offset.

[0161] Alternatively, the locking element 110 is screwed onto the threads of the first nut 60 and the third nut 90. In this case, the locking element 110 comprises an external thread that cooperates with the internal thread of the first nut and the internal thread of the second nut, respectively.

[0162] In this example, the locking element 110 comprises a first section 115a and a second section 115b having different cross sections. In particular, the inner diameter of the second section 115b is smaller than the inner diameter of the first section 115a. The first section 115a and the second section 115b are separated by a shoulder 115c.

[0163] Figures 4 to 16 The steps of installing a module of a turbine engine are shown. It will be appreciated that the installation or reassembly of a module of a turbine engine can be performed by repeating these operations in reverse order.

[0164] like Figure 4 As shown, the first step of the method is to install the first nut 60 in the low-pressure compressor shaft 15. The first nut 60 is inserted from the upstream end 15a of the low-pressure compressor shaft 15. The first nut 60 is moved translationally along the longitudinal axis until at least a portion of the downstream annular surface 62b of the collar 62 contacts the upstream annular surface 51a of the annular protrusion 51. Thus, the first nut 60 is stuck on the low-pressure compressor shaft 15.

[0165] The method comprises a second step of tightening the low-pressure shaft 9 onto the first nut 60 (the first nut being stuck in the low-pressure compressor shaft 15). To this end, the low-pressure shaft 9 is inserted into the low-pressure compressor shaft 15 by sliding using the splines 50, 53. The first nut 60 enables the low-pressure shaft 9 to be fixed to the low-pressure compressor shaft 15.

[0166] exist Figure 5 and Figure 6In the method, the method comprises a third step of limiting the translational movement of the first nut 60. The translation is limited by the anti-displacement member 65. This step comprises engaging the anti-displacement member 65 in the low-pressure compressor shaft 15. The anti-displacement member 65 is translationally displaced along the longitudinal axis to move the anti-displacement member from the disengaged position to an engaged position at least engaged with the low-pressure compressor shaft 15. In this engaged position of the anti-displacement member 65, the teeth 68 engage in the recess 70 of the low-pressure compressor shaft 15, and the downstream face 67b of the annular wing 67 of the anti-displacement member 65 faces the upstream annular face 62a of the collar 67 of the first nut 60. In this way, the first nut 60 can not move upstream along the longitudinal axis X (or at least over a short distance corresponding to the axial gap J1), but can still pivot. In particular, the teeth 68 make it possible to at least partially form the axial gap J1 that allows the first nut 60 to rotate freely.

[0167] refer to Figure 7 and Figure 8 , the method includes the fourth step of axially fixing the anti-displacement member 65. This enables the anti-displacement member 65 to be maintained so that the anti-displacement member axially limits the first nut 60 upstream. For this reason, the fourth step includes the sub-step of screwing the second nut 73 onto the low-pressure compressor shaft 15. In this way, the second nut 73 moves from the unscrewing position to the screwing position. The screwing step is carried out using another suitable tool (not shown) that is also inserted into the interior of the low-pressure compressor shaft. Screw the second nut 73 until the second nut is axially tightened against the anti-displacement member 65. In the screwing position, the internal thread 74 engages with the external thread 76, and the second annular surface 74b of the second nut 73 contacts the upstream face 67a of the annular wing 67 of the anti-displacement member 65. The low-pressure compressor shaft 15 is also prevented from moving downstream because the low-pressure compressor (that is, the second nut 73) prevents the low-pressure compressor and the low-pressure turbine from moving closer.

[0168] The method further comprises a fifth step of locking the second nut 73 to prevent rotation. The method comprises a sub-step of installing a first locking system 77. Advantageously, the first locking system 77 is a nut brake. Of course, other devices having the same function are also possible. Initially, the first ring element 78 is moved from the disengaged position to the engaged position. When moving from one position to another, the radial teeth 82 axially pass through the slots 81 in the second nut 73 and also through the radial recesses 84 arranged radially outside the second nut 73. The second nut 73 is screwed so that the slots face the radial recesses 84. In this way, the first ring element 78 extends through the first nut 60 and the low-pressure compressor shaft 15 so that the radial teeth 84 can not rotate around the longitudinal axis X. This is also possible because the outer diameter of the radial teeth is greater than the outer diameter of the second nut 73.

[0169] The first ring element 78 extends radially around the anti-displacement member 65. In a second step, the second ring element 85 is moved from the disengaged position to the engaged position. In the engaged position, the second ring element 85 is inserted into the annular groove 87 of the second nut 73. The radial teeth are axially blocked by the second ring element 85.

[0170] refer to Fig.10 , the method comprises a sixth step of mounting the third nut 90 on the input shaft 12. The third nut 90 is inserted in the upstream direction from the downstream end 12b of the input shaft 12. The third nut 90 is then located in the cavity 91 of the input shaft 12. This mounting is possible because the outer diameter of the annular bottom plate 94 is smaller than the inner diameter of the input shaft 12 measured at the peripheral annular surface 105 of the radial lug 93.

[0171] After being inserted into the cavity 91 , the third nut 90 is in a standby state.

[0172] refer to Fig.11 and Fig.12 , the method comprises a seventh step of clamping the third nut 90 in the cavity 91. To this end, the seventh step comprises a sub-step of mounting the third ring element 101 on the input shaft 12. The third ring element 101 is moved from the disengaged position to the engaged position. When moving from one position to the other, the third ring element 101 is positioned so that the radial teeth 103 axially pass through the radial recesses 104. Once the third ring element 101 is located in the cavity 91, the third ring element is Fig.12 The third nut 90 is rotated as shown so that the radial teeth 103 no longer face the radial recesses 104. In the engaged position, the downstream face 103b of the teeth faces the upstream face 93a of the radial lug 93. The downstream face 94b of the third nut 90 also faces the upstream face 101a of the third ring element 101, and the downstream face 94b is configured to contact the upstream face 101a. The inner diameter of the ring element 101 is smaller than the outer diameter of the annular bottom plate 94, and the third ring element 101 is configured to extend around the cylindrical body of the third nut 90. This configuration makes it possible to reduce the radial aperture at the downstream end 15b of the input shaft 12 defined by the peripheral annular surface 105, which prevents the third nut 90 from being removed downstream. Since the inner diameter of the third ring element 101 is smaller than the inner diameter of the lug 93 (defined by the annular surface 105), the contact surface with the third ring element 101 is larger. The third nut 90 is enclosed or stuck in the cavity 91.

[0173] refer to Fig.14, the method comprises an eighth step of clamping the third ring element 101 in the cavity 91. To this end, the method comprises a sub-step of moving the fourth ring element 107 from the disengaged position to the engaged position. In the engaged position, the fourth ring element 107 is inserted into the annular groove 108 of the input shaft 12. The radial teeth 103b are axially locked by the fourth ring element 107. More specifically, the third ring element 101 may not move axially downstream.

[0174] refer to Fig.15 , the method comprises a ninth step of fixing the input shaft 12 to the low-pressure compressor shaft 15. To this end, the downstream end 12b of the input shaft 12 is inserted inside the upstream end 15a of the low-pressure compressor shaft 15. The input shaft 12 is free to slide along the longitudinal axis relative to the low-pressure compressor shaft 15 by means of the splines 47, 49. In this way, the input shaft 12 is also moved from the disengaged position to the engaged position. In the engaged position, the splines 47, 49 are engaged and the downstream face 93b of the downstream end 12b of the input shaft 12 is in contact with the annular surface 86 of the low-pressure compressor shaft 15.

[0175] refer to Fig.16 , the method comprises a tenth step of screwing the third nut 90. In this way, the third nut 90 is moved from the unscrewing position to the screwing position. This screwing step is performed using a suitable tool (not shown) that is also inserted from upstream into the input shaft 12 of the reducer 3. The third nut 90 is screwed until the third nut is axially tightened against the third ring element 101. In the screwing position, the external thread 95 of the third nut 90 engages with the internal thread 72 of the anti-displacement member 65. Similarly, in the screwing position, the downstream face 94b of the third nut 90 contacts the upstream face 101a of the third ring element 101.

[0176] Finally, the method comprises an eleventh step of engaging the locking element 110. The locking element 110 is moved from the disengaged position to the engaged position. The locking element 110 is previously inserted into the low-pressure compressor shaft from upstream and from the input shaft 12. The engagement step is performed using a suitable tool (not shown) that is also inserted into the interior of the input shaft 12 from upstream. In the engaged position, the first external splines of the locking element 110 engage with the internal splines 112 of the first nut 60, and the second external splines 113 of the locking element 110 engage with the internal splines 114 of the third nut 90. The locking element 110 prevents the first nut and the second nut from loosening or unscrewing.

[0177] With this construction, it is possible to remove and install only the input shaft 12 of the reducer 3, thereby keeping the other shafts of the module in the installed position. The various nuts 60, 73, 90 and the components (ring element, anti-displacement component and locking element) are tightened together, preventing rotation on the one hand and axial displacement on the other.

[0178] The low-pressure compressor shaft 15 is independent of the input shaft 12 and the low-pressure shaft 9. When the input shaft 12 is disassembled, the low-pressure shaft 9 remains fixed to the low-pressure compressor shaft 15 via the first nut 60, the anti-displacement member 65 and the second nut 73.

Claims

1. A turbine engine (1), in particular a turbine engine for an aircraft, the turbine engine (1) having a longitudinal axis (X) and comprising: - a first module (11) comprising a reducer (3) comprising an input shaft (12) centered on the longitudinal axis (X), - a second module (14), comprising a low-pressure compressor (4), said second module (14) being connected to said first module (11), a third module (16) comprising a low-pressure shaft (9) centered on the longitudinal axis X, the low-pressure shaft (9) comprising an upstream end (9a) connected to the input shaft (12), and - locking means (42) configured to axially fix the third module (16) relative to the first module (11), Characterized in that the locking device (42) is configured to axially fix the second module (14) relative to the first module (11) and the third module (14), and the locking device comprises: a first nut (60) which is screwed onto the thread of the upstream end (9a) of the low-pressure shaft (9) and is in contact with the annular protrusion (51) of the second module (14), an anti-displacement member (65) configured to axially limit the displacement of the first nut (60), a second nut (73) which is screwed onto the thread of the second module (14) and is configured to axially fix the anti-displacement member (65), and - a third nut (93) which is screwed onto the anti-displacement member (65).

2. Turbine engine according to the preceding claim, characterized in that The locking device (42) includes a locking element (110) cooperating with the first nut (60) and the third nut (90).

3. A turbine engine (10) according to any one of the preceding claims, characterised in that The first nut (60) is mounted so as to rotate freely about the longitudinal axis (X).

4. A turbine engine (1) according to any one of the preceding claims, characterised in that The second module (14) comprises a low-pressure compressor shaft (15) connected to the low-pressure compressor (4) and centered on the longitudinal axis (X), the low-pressure compressor shaft (15) being connected to the input shaft (12) and the low-pressure shaft (9).

5. Turbine engine (1) according to the preceding claim, characterized in that The low-pressure compressor shaft (15) includes the annular protrusion (51), and the first nut (60) includes a downstream surface (62b) in contact with an upstream surface (51a) of the annular protrusion (51).

6. The turbine engine (1) according to claim 4 or 5, characterized in that The anti-displacement member (65) includes a plurality of teeth (68), each tooth being configured to engage in a recess (70) in the low-pressure compressor shaft (15).

7. Turbine engine (1) according to the preceding claim, characterized in that The outer diameter of the plurality of teeth (68) is greater than the outer diameter of the collar (62) of the first nut (60).

8. A turbine engine (1) according to any one of the preceding claims, characterised in that The second nut (73) is configured to be locked against rotation by a first locking system (77).

9. Turbine engine (1) according to claims 4 to 8, characterized in that The first locking system (77) comprises: a first ring element (78) centered on the longitudinal axis (X) and configured to come into contact with a radial annular surface (74a) of the second nut (73), the first ring element (78) comprising a plurality of radial teeth (82), each radial tooth configured to engage in a radial recess (84) of the low-pressure compressor shaft (15), and - a second ring element (85) centered on said longitudinal axis (X) and received in an annular groove (87) of said second nut (73), said annular groove (87) being arranged upstream of said radial annular surface (74a).

10. A turbine engine according to any one of the preceding claims, characterised in that The turbine engine comprises a second locking system (100) configured to enclose the third nut (90) in an annular cavity (91) of the input shaft (12).

11. Turbine engine (1) according to the preceding claim, characterized in that The second locking system (100) comprises: a third ring element (101) centered on the longitudinal axis (X) and comprising a plurality of radial teeth (103) having a downstream face (103b) configured to come into contact with an annular face (93a) of the input shaft (12), the third ring element (101) comprising an upstream face (101a), against which the downstream face (94b) of the third nut (90) abuts, and - a fourth ring element (107) centered on the longitudinal axis (X) and received in an annular groove (108) of the input shaft (12), the fourth ring element (107) facing the downstream face (103b) of the radial tooth (103).

12. Turbine engine (1) according to any one of the preceding claims, characterized in that The first module (11) comprises a fan (2) connected to a fan shaft (13) and arranged upstream of the second module (14), and the low-pressure shaft (9) drives the fan shaft (13) to rotate by means of the reducer (3).

13. The turbine engine (10) according to claim 12, characterized in that The fan (2) is a ducted fan.

14. A method for installing a turbine engine according to any one of the preceding claims, characterized in that The method comprises the following steps: - screwing the first nut (60) onto the low-pressure shaft (9), - limiting the translation of the first nut (60) along the longitudinal axis on the low-pressure compressor shaft (15) by means of the anti-displacement member (65), - axially fixing the anti-displacement member (65) by means of the second nut (73), - Screwing the third nut (90) onto the anti-displacement member (65).

15. The method according to claim 14, characterized in that The method includes the step of engaging a locking element (110) on the third nut (90) and the first nut (60).

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