MODULARITY OF AN AIRCRAFT TURBOMACHINE BY ACCORDING TO AN AXIAL AND ROTATIONAL LOCKING DEVICE, CORRESPONDING ASSEMBLY METHOD
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2022-09-26
- Publication Date
- 2026-06-19
Abstract
Description
Description Title of the invention: MODULARITY OF AN AIRCRAFT TURBO ENGINE BY AN AXIAL AND ROTATIONAL LOCKING DEVICE, CORRESPONDING MOUNTING METHOD Field of invention
[0001] = The present invention relates to solutions for facilitating the modularity of a tur- aircraft engine. Technical background
[0002] = An aircraft turbomachine is often produced in the form of an assembly of modules which can each have fixed parts and moving parts. A module is defined as a subset of an engine that has character- geometric characteristics at its interfaces with adjacent modules suf- sufficiently precise so that it can be delivered individually, and which has undergone a separate balancing when it includes rotating parts. The assembly of the modules allows you to build a complete engine, reducing as much as possible the balancing and matching operations of interface parts.
[0003] = The modularity of a turbomachine is a key element for its maintenance. Indeed, during an intervention, the parts must be easily accessible without having to disassemble a significant number of parts of the engine. In practice, the turbomachine is configured to obtain a division into major and minor modules. For example, for a turbomachine having an upstream fan (the terms "upstream" and “downstream” are assessed in relation to the flow of gases in the turbomachine), This is configured with three major modules: a major upstream module for the front part including the fan, a major intermediate module for the part intermediate comprising the low pressure compressor and the high pressure body and a major downstream module for the rear part including the low pressure turbine the low pressure shaft. In this specific example, the low pressure body is divided into two modules.
[0004] It is possible that the low pressure body is divided equally into three modules with the low pressure compressor arranged independently from the rest of the module intermediate major.
[0005] Maintenance is particularly difficult on a turbomachine comprising a reducer and possibly a system for changing the pitch of the upstream blades. In effect, the speed reducer is attached either to the upstream module or to the major module intermediate. The speed reducer comprises an input shaft which is connected to a low pressure compressor rotor and a low pressure turbine rotor. In par- In particular, the intermediate major module and the downstream major module which include components of the low pressure body, and the upstream module, are fixed to each other by means of a nut which is centered on the axis of the turbomachine and which is used to axially tighten the input shaft of the speed reducer and the low pressure shaft. During a maintenance operation on the speed reducer or other components of the turbomachine of one of the modules described above, this nut must be unscrewed from upstream using a tool that is inserted into the turbomachine along its longitudinal axis. This allows the downstream major module to be separated. However, this is not sufficient to completely free the input shaft since the latter is also connected to the rotor of the low-pressure compressor by means of a journal that is fixed to the input shaft and that must also be removed. The rotor of the low-pressure compressor of the intermediate major module also comprises bearings whose internal rings are fixed to the input shaft. The problem in this case is therefore the number of parts to be removed to disassemble a component of one of the modules and specifically the input shaft. It is generally not possible to disassemble the speed reducer without disassembling a large part of the turbomachine including the upstream module, the major intermediate module and the major downstream module. The present invention provides a solution to at least some of the problems mentioned above which simplifies the modularity of an aircraft turbomachine and which does not penalize the efficiency of the turbomachine. Summary of the invention We achieve this objective in accordance with the invention by means of a turbomachine, in particular an aircraft turbomachine, the turbomachine having a longitudinal axis and comprising: - a first module comprising a speed reducer which has an input shaft centered on the longitudinal axis, - a second module comprising a low pressure compressor, the second module being connected to the first module, - a third module comprising a low pressure shaft which is centered on the longitudinal axis, the low pressure shaft comprising an upstream end connected to the input shaft, and - a locking device configured so as to axially immobilize the third module relative to the first module, the locking device being configured to axially immobilize the second module relative to the first module and the second module and comprises: - a first nut which is screwed onto a thread of the upstream end of the low pressure shaft and rests against an annular projection of the second module, - an anti-displacement member which is configured so as to axially limit the displacement of the first nut, - a second nut which is screwed onto a thread of the second module and which is configured so as to axially immobilize the anti-displacement member, and - a third nut which is screwed onto the anti-displacement member. Thus, this solution achieves the above-mentioned objective. The low-pressure turbine module and the low-pressure compressor can thus be dismantled in a reduced number of operations compared to the other modules and without dismantling the other adjacent modules. This applies in particular to the input shaft, which is subject to numerous stresses and can now be checked and replaced easily and quickly. The input shaft can be dismantled independently of the other shafts thanks to the locking device, which comprises several nuts and members tightened / engaged on each other to perform anti-rotation and anti-displacement or axial locking functions. Furthermore, this configuration allows for increased modularity and time savings in the inspection of the parts and the independent dismantling of some of them.This modularity is part of an approach to reducing environmental impact since it allows only the necessary components to be repaired and checked and reduces the downtime of the turbomachine. The turbomachine according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: - the locking device comprises a locking element cooperating with the first nut and the third nut. - the first nut is mounted to rotate freely around the longitudinal axis. - the second module comprises a low pressure compressor shaft which is connected to the low pressure compressor and which is centered on the longitudinal axis, the low pressure compressor shaft being connected to the input shaft and to the low pressure shaft. - the low pressure compressor shaft comprises the annular projection and the first nut has a downstream face bearing against an upstream face of the annular projection. - the anti-displacement member comprises a plurality of teeth each intended to engage in a notch in the low pressure compressor shaft. - the plurality of teeth has an external diameter greater than an external diameter of a collar of the first nut. - the second nut is intended to be locked in rotation by a first locking system. - the first blocking system includes: - - a first ring, centered on the longitudinal axis and intended to come to bear against a radial annular face of the second nut, the first ring comprising a plurality of radial teeth each intended to engage in a radial notch of the low pressure compressor shaft, and - - a second ring, 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 face. - the turbomachine comprises a second locking system configured so as to enclose the third nut in an annular cavity of the input shaft. - the third nut is intended to be blocked in translation upstream at least by a second blocking system. - the second blocking system includes: - - a third ring, centered on the longitudinal axis, and comprising a plurality of radial teeth which have downstream faces intended to bear against an annular face of the input shaft, the third ring comprising an upstream face against which a downstream face of the third nut abuts, and - - A fourth ring, centered on the longitudinal axis, received in an annular groove of the input shaft, the fourth ring being opposite the downstream faces of the radial teeth. - the first module comprises a blower which is connected to a blower shaft and which is arranged upstream of the second module, the low pressure shaft rotating the blower shaft via the speed reducer. - the blower is shrouded. - the reducer is located in a lubrication enclosure. - the low pressure compressor shaft is independent of the input shaft and the low pressure shaft. - the low pressure shaft comprises an upstream end which extends inside the low pressure compressor shaft, the first nut, the second nut and the third nut being mounted inside the low pressure compressor shaft. - the low pressure compressor shaft is connected to an upstream end of the low pressure shaft and to a downstream end of the input shaft. - the low pressure compressor shaft is connected to a low pressure compressor rotor. - the low pressure compressor shaft is connected to the low pressure compressor rotor by means of a journal, the journal being integral with the low pressure compressor rotor and the low pressure compressor shaft. - the journal is formed in one piece with the low pressure compressor shaft. - the third module comprises a low pressure turbine connected to the low pressure shaft, the low pressure shaft comprises a downstream end connected to a rotor of low pressure turbine. - the input shaft of the speed reducer has an internal diameter which is smaller than the internal diameter of the low pressure compressor shaft. - the input shaft of the speed reducer has an internal diameter which is greater than the internal diameter of a downstream end of the low pressure compressor shaft. - the first nut includes a thread which is screwed onto the third module. - the radial notches of the low pressure compressor shaft extend radially outside the second nut. The invention further relates to an aircraft comprising at least one turbomachine as mentioned above. The invention also relates to a method of assembling a turbomachine as mentioned above, the method comprising the steps of: - screwing the first nut onto the low pressure shaft, - limitation in translation of the first nut on the low pressure compressor shaft along the longitudinal axis by means of the anti-displacement member, - axial immobilization of the anti-displacement member by means of the second nut, and - screwing the third nut onto the anti-displacement device. According to a characteristic of the method, the latter comprises a step of engaging a locking element on the third nut and on the first nut. Brief description of the figures Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which: [Fig.1] is a schematic and axial sectional half-view of an aircraft turbomachine: [Fig.2] is a detail view of [Fig.1] according to the invention; [Fig. 3] is a perspective view illustrating a shaft of one of the modules of a turbomachine according to the invention; [Fig.4] is a perspective view of a shaft in which a first nut is mounted following a step of a mounting method according to the invention; [Fig. 5] is a perspective view of a shaft in which an anti-displacement member of a first nut is mounted following a step of a mounting method according to the invention; [Fig.6] is a detail view of [Fig.5] according to the invention; [Fig.7] is a perspective view and substantially along a longitudinal section plane- tudinal of a shaft in which a second nut is mounted and a system for locking this nut according to a step of a mounting method according to the invention; [Fig.8] illustrates in more detail a first rotational locking system for a second nut according to the invention: [Fig.9] is a detailed view of [Fig.7] and substantially along a radial section plane of the shaft in which the second nut according to the invention is mounted; [Fig. 10] is a perspective view of a shaft in which a third nut is mounted according to a step of a mounting method according to the invention; [Fig. 11] is a perspective view of a shaft in which a locking system is mounted according to a step of a mounting method according to the invention; [Fig.12] illustrates in more detail a third nut according to the invention; [Fig.13] is a perspective view of a step in the assembly process according to [Fig.11]; [Fig. 14] is a perspective view of a shaft in which a locking system is mounted according to a step of a mounting method according to the invention; [Fig. 15] is a perspective view in which two shafts are assembled together according to a step of a mounting method according to the invention; and [Fig.16] is a perspective view in which a locking device makes it possible to lock the shafts in translation and rotation following a step of a mounting method according to the invention. Detailed description of the invention The invention applies to an aircraft turbomachine 1 such as that shown in [Fig. 1] and which is a turbojet engine equipped with a ducted fan 2 and a speed reducer 3. Of course, the invention is not limited to a turbojet engine and can be applied to any type of turbomachine equipped in particular with a speed reducer. The turbomachine | extends along a longitudinal axis X which is generally the axis of rotation of its rotors. The turbomachine 1 comprises from upstream to downstream along the longitudinal axis X and the flow of gases, 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. The low pressure compressor 4 and the low pressure turbine 7 are mechanically connected by a low pressure shaft 9 so as 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 so as to form a high pressure body. The low pressure shaft 9 extends at least partly inside the high pressure shaft 10 and are coaxial. The turbomachine | is configured with several modules that are assembled / connected to each other and which facilitate its maintenance. Shafts and / or interfaces make it possible to create these connections. A first module 11 comprises the blower 2 and the speed reducer 3. The latter advantageously comprises an input shaft 12 which is centered on the longitudinal axis X. The input shaft 12 is advantageously part of the first module 11, The blower 2 comprises a blower shaft 13 which is advantageously rotated by the low pressure shaft 9 via the speed reducer 3. A second module 14 comprises the low pressure compressor 4. The second module 14 also comprises a low pressure compressor shaft 15 to which the low pressure compressor 4 is connected. The low pressure compressor shaft 15 is centered on the longitudinal axis X. A third module 16 comprises the low pressure turbine 7 and the low pressure shaft 9 which is centered on the longitudinal axis X. The low pressure shaft 9 advantageously comprises an upstream end 9a connected to a rotor of the low pressure compressor and a downstream end 9b connected to a rotor of the low pressure turbine. The upstream end 9a is connected to the input shaft 12 of the speed reducer 3. A fourth module 17 comprises the high pressure compressor 5. Advantageously, the fourth module 17 comprises the high pressure turbine 7. The fourth module 17 also comprises the annular combustion chamber 6 which is axially interposed between the high pressure compressor 5 and the high pressure turbine 7. In this configuration, the low-pressure body of the turbomachine | is divided into three modules. Alternatively, the low-pressure body is divided into two modules with the low-pressure compressor being part of the second module. The speed reducer 3 (known by the English acronym "RGB") includes an epicyclic gear train. Of course, the speed reducer could include a planetary type gear. The speed reducer 3 typically comprises a sun gear 20 (or internal planetary gear), a plurality of satellites 21 (which are pinions), a planet carrier 22 and an external ring gear 23 (or external planetary gear). The sun gear 20 is centered on the longitudinal axis X. The external ring gear 23 is centered on the longitudinal axis X and extends around the sun gear 20. The satellites 21 are arranged between the sun gear 20 and the external ring gear 23 and are carried by the planet carrier 22. The satellites 21 are each mounted to rotate freely around a satellite axis using a bearing and mesh with external teeth of the sun gear 20 and internal teeth of the external ring gear 23. In this case, the external crown 23 is stationary and fixed to a stator of the turbine bomachine which is here an input casing 24. The solar 20 is rotatable and coupled to the input shaft 12 which itself is connected to the low pressure shaft 9. The planet carrier 22 is also rotatable and coupled to the fan shaft 13. The fan 2 is therefore driven in rotation by the low pressure shaft 9 via the reducer 3. In the case of a planetary type gear reducer, the external crown is rotationally fixed to the fan shaft, the planet carrier is fixed to a fixed structure such as the input casing 24. The reducer 3 of [Fig. 1] is advantageously arranged in a lubrication enclosure 25 which extends around the longitudinal axis X. The enclosure 25 therefore has a generally annular shape. The enclosure 25 is delimited by the fan shaft 13 and the input shaft 12 at its internal periphery. At its external periphery, the lubrication enclosure 25 is delimited advantageously, but not limited to, by the input casing 24 which extends around the reducer 3. The enclosure 25 is delimited upstream by a first bearing support 26 which is annular. The first bearing support 26, for example, comprises an external end which is fixed to the input casing 24 and an internal end which holds external bearing rings of two rolling bearings 27. Advantageously, the rolling bearings 27 comprise internal rings which are fixed to the fan shaft 13. These bearings allow the rotational guidance of at least the fan shaft 13. One of the upstream bearings closest to the speed reducer 3 also allows the planet carrier to be guided in rotation in a more stable manner. This bearing closest to the reducer is optional. Finally, the enclosure 25 is delimited downstream for example by a second bearing support 28 which is annular. The second bearing support 28 comprises an external end 28a which is fixed to the input casing 24 and an internal end 28b which holds external rings of two rolling bearings 29. Advantageously, the two downstream rolling bearings 29 allow the guidance of the input shaft of the speed reducer and the low pressure compressor shaft (which is integral with the input shaft). In the present example, the rolling bearings 29 comprise inner rings which are fixed to the low pressure compressor shaft 15. The second bearing support 28 comprises an annular ferrule 30 whose first end 30a is fixed to the second bearing support 28 and whose second end 30b cooperates with sealing elements 31 installed around the low pressure compressor shaft 15. With reference to [Fig. 1], the enclosure 25 also comprises sealing means sealingly closing the enclosure 25. These sealing means comprise a first removable cover 32 provided to close the enclosure 25 upstream and sealed manner and a second removable cover 33 provided to close the enclosure downstream and also in a sealed manner. The first cover 32 is mounted inside the fan shaft 13 and is located near the speed reducer 3 along the longitudinal axis. The second cover 33 is mounted inside the input shaft 12 and at a downstream end 12b thereof. This second cover 33 is mounted downstream of the speed reducer 3 (and more precisely downstream of flexibility means in an advantageous manner). The low pressure compressor shaft 15 and the input shaft 12 are both advantageously hollow. The low pressure shaft 9 is also hollow. The turbomachine 1 also comprises an intermediate casing 34 which is interposed between the low pressure compressor 4 and the high pressure compressor 5, an inter-turbine casing 35 which is interposed between the high pressure turbine 7 and the low pressure turbine 8 and an exhaust casing 36 which is located downstream of the low pressure turbine 8. In [Fig. 2], a set of shafts of the turbomachine are connected to each other and locked in position relative to each other. The set comprises a first shaft and a second shaft. In the present example, the first shaft is the input shaft 12. The second shaft is the low pressure compressor shaft 15. The set of shafts also comprises a third shaft which is the low pressure shaft 9. First coupling means 40 are configured to (removably) connect the first module 11 and the second module 14. Second coupling means 41 are configured to (removably) connect the second module 11 and the third module 15. The turbomachine comprises a locking device 42 configured so as to connect the modules together and to axially immobilize the modules together. The low pressure compressor shaft 15 is connected to the low pressure compressor rotor via a journal 43. In particular, the second module 14 comprises (in addition to the low pressure compressor) the journal 43 which is rotationally fixed to the rotor of the low pressure compressor and to the low pressure compressor shaft 15. The low pressure compressor shaft 15 is connected to the input shaft 12. As shown in [Fig. 3], the low pressure compressor shaft 15 comprises a generally straight cylindrical shape with axis A. The low pressure compressor shaft advantageously extends between an upstream end 1Sa and a downstream end 15b. The annular journal 43 extends radially from an external surface of the low pressure compression shaft 15 to a first end 43a. The journal 43 comprises a second end 43b which is secured to the rotor via fastening members such as a threaded rod (screw) and a nut. In the example shown, the journal 43 is formed in one piece with the low pressure compressor shaft. pressure 15. Alternatively, the journal 43 is an added part and its internal end 43a is fixed and immobilized axially at the downstream end 15b of the low pressure compressor shaft 15. The low pressure compressor shaft 15 advantageously comprises an annular bearing surface 44 which rises radially from the external surface thereof. The inner ring 29a of one of the bearings 29 bears axially against this annular bearing surface 44. The low pressure compressor shaft 15 comprises an external thread 45 which is intended to engage with an internal thread of a bearing nut 46 which axially locks the internal ring 29a. The external thread 45 is arranged towards the upstream end 15a of the low pressure compressor shaft 15. As stated previously, 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 by splines so as to transmit a rotational torque. For this purpose and as shown in [Fig. 2], the first coupling means 40 comprise first internal splines 47 which are formed on an internal surface 48 of the low pressure compressor shaft 15. The first internal splines 47 are oriented along the axis λ (and along the longitudinal axis) and are arranged regularly around the axis λ. The first internal splines 47 are configured to engage with corresponding first external splines 49 of the input shaft 12. The first internal splines 47 are advantageously located near, but not limited to, the upstream end 15a of the shaft 15. The low pressure compressor shaft 15 comprises second internal splines 50 which are formed on the internal surface 48. These second external splines 50 are oriented along the axis A and are regularly distributed around this axis A. These are advantageously located at the downstream end 15b of the low pressure compressor shaft. In the example shown, the low-pressure compressor shaft 15 comprises a first shaft portion 15aa, a second shaft portion 15ab and a third shaft portion 15ac. The first portion 15aa comprises an internal diameter D1 which is greater than the internal diameter D2 of the second portion 15ab. The internal diameter D2 of the second portion 15ab is greater than the internal diameter D3 of the third portion 15ac. The low-pressure compressor shaft 15 advantageously, but not limited to, comprises an annular projection 51 which extends radially inwardly thereof. The annular projection 51 is arranged between the first shaft portion 15aa and the third shaft portion 15ac. More specifically, the annular projection 51 is arranged between the second portion 15ab and the third portion 15ac. In the present example, the annular projection 51 is formed upstream of the grooves 50. The low-pressure compressor shaft 15 further comprises an annular shoulder 52 extending radially inwardly thereof. The shoulder 52 is arranged between the first shaft portion 15aa and the third shaft portion 15ac. More specifically, the annular shoulder 52 is arranged upstream of the annular projection 51 along the longitudinal axis X. In Figures 2 and 3, the downstream end 12b of the input shaft 12 extends inside the low-pressure compressor shaft 15. The corresponding first external splines 49 are formed on an external surface of the input shaft 12. The first external splines 49 are located at the downstream end 12b of the shaft 12. The latter has an external diameter at the downstream end 12b which is advantageously substantially smaller than the internal diameter DI1 of the first portion 15aa of the low-pressure compressor shaft 15. The input shaft 12 further has an external diameter D4 at the speed reducer 3 which is, advantageously, smaller than the external diameter of its downstream end 12b. The efficiency of the turbomachine is also a function of the radial size of the speed reducer, the diameter of the input shaft 12 must be small so that the ratio of the diameters of the external crown and the sun gear is close to 1. Advantageously, the diameter D4 of the input shaft 12 is between: - a radius sufficient to be able to pass the rotation torque, - a radius sufficient to be able to pass an external tool (described later) inside the input shaft 12, - the lowest possible radius for mass savings, and - the lowest possible radius to leave height for the flexible elements (the height of these elements induces the flexibility of the part). Advantageously, the reduction ratio of the speed reducer is between 2.5 and 7. The diameter of the input shaft 12 must be small enough to achieve the desired reduction ratio while being large enough to be able to pass the torque and a tool. The ratio between the diameter of the crown and the diameter of the input shaft 12 must be the reduction ratio - 1 (the Willis formula expressing a reduction ratio between the crown and the sun, in the reference frame of the planet carrier). The input shaft 12 has a certain flexibility so as to avoid hyperstaticism in the speed reducer 3. The input shaft 12 advantageously, but not limited to, bellows, which with the splines, make it possible to achieve this flexibility. Thus, misalignment can occur between the shaft inlet 12 and the low pressure compressor shaft 15 which is particularly interesting in the case of a relatively long engine. In [Fig. 1], the low pressure compressor shaft 15 is rotationally fixed to the low pressure shaft 9. The low pressure compressor shaft 15 is coupled to the low pressure shaft 9 advantageously by splines so as to transmit a rotational torque. The second coupling means 41 are advantageously formed by the splines. 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 comprises second external splines 53 which correspond to and engage with the second internal splines 50 of the low pressure compressor shaft 15. The second external splines 53 are arranged on an external surface of the low pressure shaft 9 and towards its upstream end.The low pressure shaft 9 has an external diameter (at its upstream end 9a) which is substantially smaller than the diameter of the third portion 15ac of the low pressure compressor shaft 15. The locking device 42 is configured to immobilize the low pressure shaft 9 relative to the low pressure compressor shaft 15, the input shaft 12 relative to the low pressure compressor shaft 15 and the input shaft 12 relative to the low pressure shaft 9. With reference to [Fig. 4], the locking device 42 comprises a first nut 60 which is configured so as to axially block at least in part the low pressure shaft 9 relative to the low pressure compressor shaft 15. Advantageously, the first nut 60 is screwed onto a thread of the upstream end 9a of the low pressure shaft 9 and bears against an annular projection 51 of the second module 14. The first nut 60 is configured so as to axially immobilize the low pressure shaft 9 relative to the low pressure compressor shaft 15 and to carry out the recovery of the axial thrust of the low pressure turbine. Advantageously, the first nut 60 comprises a cylindrical body 61 with an axis of revolution B. The first nut 60 comprises a collar 62 which extends radially outwards from one end of the cylindrical body 61. The first nut 60 comprises in the present example an L-shaped axial section. The first nut 60 is screwed onto the low pressure shaft 9 and is centered on the longitudinal axis. The first nut 60 is disposed radially, advantageously, between the low pressure compressor shaft 15 and the low pressure shaft 9. More specifically, the first nut 60 comprises an external thread 63 which engages with an internal thread 64 of the low pressure shaft 9. The external thread 63 is carried by an external surface of the cylindrical body 61. The internal thread 64 is advantageously located at the upstream end 9a of the low pressure shaft 9. In the present example, the external diameter of the nut 60, at the level of the cylindrical body 61, is less than the internal diameter of the low pressure shaft 9. We can see that the internal diameter of the nut is less than the internal diameter of the input shaft 12 (see [Fig.2]). The collar 62 of the first nut 60 comprises an annular face intended to bear against a complementary annular surface of the annular projection 51. In particular and advantageously, the annular face is a downstream annular face 62b and the complementary annular surface is a complementary upstream annular surface 51la. With reference to figures 5 and 6, the locking device 42 comprises an anti-displacement member 65 which is configured so as to “lower” the fixing means (here thread) and to allow assembly between the input shaft 12 and a 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 and the external thread 95 of the cylindrical body 90a of the third nut 90). Advantageously, the collar 62 is arranged between the anti-displacement member 65 and the annular projection 51. Advantageously, the first nut 60 is mounted to rotate freely in the low-pressure compressor shaft 9 as explained later. There is a certain axial and radial clearance between the other parts. When the various members are loosened, the first nut 60 can move axially and rotate freely in a short space. When the various members are tightened, a first rotation locking system 77 abuts against the anti-displacement member 65. The latter allows axial displacement (depending on the clearance which is provided) of the first nut. The first nut 60 comes opposite and / or abuts against the annular projection 51 of the compressor shaft 15. The anti-displacement member 65 advantageously comprises a cylindrical body 66 with an axis of revolution C. The anti-displacement member 65 is centered on the axis X in the installation situation. The anti-displacement member 65 advantageously comprises an annular wing 67 which extends radially outward from one end of the cylindrical body 66. A plurality of teeth 68 extend from a downstream face 67b of the annular wing 67 and along the axis of revolution C. The teeth 68 are located in particular close to the external peripheral edge 69 of the annular wing 67. The downstream face 67b is arranged opposite an upstream annular face 62a of the collar 67 of the first nut 60. Advantageously, at least one axial clearance J1 is provided between the downstream face 67b and the upstream annular face 62a, which allows the rotation of the first nut 60 around the longitudinal axis X. The anti-displacement member 65 comprises teeth 68 (those described previously) which are intended to engage respectively in notches 70 of complementary shape of the second module. In particular, as can be seen in [Fig. 3], the low-pressure compressor shaft 15 comprises notches 70 which are oriented along the longitudinal axis. The notches 70 are advantageously arranged upstream of the annular projection 51. In the installed situation, the teeth 68 extend radially outside the annular edge 71 of the collar 62 of the first nut 60. In other words, the external diameter of the plurality of teeth 68 is greater than the external diameter of the annular edge 71 of the collar 62. The distance L] measured between the bottom of the notches 70 and the downstream face 67b (in the installation situation along the longitudinal axis X) is greater than the distance L2 measured between the upstream annular surface Sla complementary to the projection 51 and the downstream face 67b. In the present example, the bottom of the notches 70 is in the same plane as the complementary upstream annular surface 51a. This difference between the distances L1 and L2 creates the axial clearance J1 which is referenced in [Fig.6]. In [Fig.5], the anti-displacement member 65 includes an internal thread 72 which is formed on the internal surface of its cylindrical body 66. Advantageously, the external diameter of the cylindrical body 66 of the anti-displacement member 65 is greater than the external diameter of the cylindrical body 61 of the first nut 60. With reference to [Fig. 7], the locking device 42 also comprises a second nut 73 which is screwed onto a thread of the second module 14 and which is configured so as to axially immobilize the anti-displacement member 65, i.e. along the longitudinal axis X. The second nut 73 comprises a cylindrical body with an axis coaxial with the longitudinal axis. The cylindrical body advantageously extends between a first annular face 74a and a second annular face 74b. The second nut 73 comprises an external thread 74 formed on its external surface 75 and which is intended to engage with an internal thread 76 of the low-pressure compressor shaft 15. The internal thread 76 is provided at the second shaft portion 15ab. The second nut 73 has an external diameter which is greater than the external diameter of the anti-displacement member 65. The internal diameter of the second nut 73 is also greater than the external diameter of the anti-displacement member 65. A radial space is provided between the second nut 73 and the anti-displacement member 65. This radial space makes it possible, on the one hand, to avoid parasitic force transitions and, on the other hand, to integrate the locking rings (not shown) of the second nut 73. In the installation situation, the second annular face 74b of the second nut 73 is in support against an upstream face 67a of the annular wing 67. As can also be seen in Figures 7, 8 and 9, the second nut 73 is locked in rotation by a first rotation locking system 77. The first rotation locking system 77 advantageously comprises a first ring 78, centered on the longitudinal axis, intended to come to bear against the first annular face 74a of the second nut 73. Pins 80 extend from the first annular face 74a of the second nut 73 and at a distance therefrom, radially inwards. Advantageously, each lug 80 extends over an angular sector around the longitudinal axis. The lugs 80 are also spaced from each other so as to form slots 81. In this way, slots 81 and lugs 80 alternate around the longitudinal axis. The first ring 78 comprises a plurality of radial teeth 82 which extend from an outer peripheral edge (not shown) thereof. The radial teeth 82 are regularly distributed around the longitudinal axis X. Each radial tooth 82 is intended to engage in a corresponding radial notch 84 of the low-pressure compressor shaft 15. Advantageously, the radial notches 84 (precisely illustrated in [Fig. 3]) are open (and open) on the inner surface 48 and are turned towards the inside of the low-pressure compressor shaft 15. The notches 84 are advantageously, but not limited to, formed at the annular shoulder 52. Each radial tooth 82 is also arranged in a slot 81 of the second nut 73. As can also be seen in [Fig. 3], the radial notches 84 open onto an annular surface 86, centered on the axis X, of the low-pressure compressor shaft 15. In the present example, the annular surface 86 is advantageously carried by the annular shoulder 52. The first rotation locking system 77 further comprises a second ring 85 which is centered on the longitudinal axis X. The second ring 85 is split generally like a circlip. The second ring 85 is received in an annular groove 87 of the second nut 76. The annular groove 87 has an opening oriented towards the longitudinal axis X. The annular groove 87 is advantageously arranged upstream of the first annular face 74b. More precisely still, the annular groove 87 is formed in the lugs 80. Alternatively, the annular groove 87 is formed by a distance between the first annular face 74a of the second nut and an internal face of the lug 74a. In this way, the second ring 85 extends upstream of the first ring 78 and the lugs 80 make it possible to achieve axial locking of the second ring 85. Advantageously, the second ring 85 bears against an upstream face of the first ring 78. In [Fig. 10], the locking device 42 comprises a third nut 90 which is intended to be screwed onto the anti-displacement member 65. The third nut 90 is further intended to be immobilized axially on the input shaft 12. As illustrated, the third nut 90 is advantageously installed in an annular cavity 91 of the input shaft 12. Advantageously, but not limitingly, the annular cavity 91 is delimited along the longitudinal axis by an upstream shoulder 92 and by a radial lug 93. The annular cavity 91 is also delimited radially by a portion of the wall of the downstream end 12b of the input shaft 12. In the present example, the third nut 90 comprises a cylindrical body 90a of axis D and an annular sole 94 extending radially from one end of the third nut 90. The third nut 90 comprises an external thread 95 which is intended to engage with an internal thread 96 of the anti-displacement member 65. Advantageously, the external diameter of the cylindrical body 90a of the third nut 90 is substantially less than the internal diameter of the cylindrical body of the anti-displacement member 65. The annular sole 94 comprises an external peripheral edge 97 (see [Fig. 10]) which defines a diameter which is less than the internal diameter of the downstream end 12b of the input shaft 12. The annular sole 94 comprises an upstream face 94a and a downstream face 94b which are opposite along the axis D. Advantageously, the upstream face 94a comprises a plurality of protrusions 98 which extend along the axis D. These protrusions 98 are intended to engage in recesses of a tightening tool (not shown). The latter allows the tightening of this third nut 90 on the anti-displacement member 65. In Figures 11, 12 and 13, a second locking system 100 is provided configured so as to enclose the third nut 90 in the annular cavity 91 of the input shaft 12. Advantageously, the third nut 90 is intended to be axially locked at least in part by the second locking system 100. This axial locking occurs in particular when all the parts are tightened (screwed, etc.). The second locking system 100 advantageously comprises a third ring 101 of axis E and is centered on the longitudinal axis in the installation situation. The third ring 101 makes it possible to integrate and enclose the third nut 90 inside the input shaft 12. The third ring 101 advantageously comprises an upstream face 101a and a downstream face 101b which are connected by an internal peripheral edge 102a and an external peripheral edge 102b.The third ring 101 advantageously comprises a plurality of radial teeth 103 which extend radially outwards from the outer peripheral edge 102b. The downstream face 94b of the third nut 90 bears against the upstream face 10la of the third ring 101. Each radial tooth 103 comprises a downstream face 103b intended to be supported against an annular face (upstream face 93a) of the radial lug 93. The latter also comprises an annular downstream face 93b axially opposite the upstream face 93a. As described previously and with reference to [Fig. 10], the input shaft 12 comprises a radial lug 93 which extends radially towards the longitudinal axis X. The radial lug 93 advantageously comprises a plurality of radial notches 104 which pass through the radial lug 93 on either side along the longitudinal axis X. Each radial notch 104 has a U-shaped radial section. The openings of the radial notches 104 are oriented towards the longitudinal axis X and open on either side of the radial lug 93 onto the upstream face 93a and onto the downstream face 93b. The third ring 101 is inserted from downstream at the downstream end 12b of the input shaft 12. For this purpose, the radial teeth 103 of the third ring 101 each pass through a radial notch 104 so that the third ring 101 is arranged in the annular cavity 91 of the input shaft 12. The third ring 101 is pivoted along the longitudinal axis to make contact between the downstream faces 103b and the upstream face 93a of the radial lug 93. In the installation situation, the internal peripheral edge 102a of the third ring 101 extends radially inside the peripheral annular face 105 (or free end of the radial lug 93). The downstream face 94b of the sole is intended to come into contact with the upstream face 101a of the third ring 101. With reference to [Fig. 14], the second locking system 100 advantageously comprises a fourth ring 107 which is centered on the longitudinal axis X. The fourth ring 107 is intended to axially lock the third ring 101 in the first module, and here in particular in the input shaft 12. The fourth ring 107 is split generally like a circlip. The fourth ring 107 is advantageously received in an annular groove 108 of the input shaft 12 which is centered on the longitudinal axis. The annular groove 108 is arranged upstream of the upstream face 93a of the radial lug 93. More precisely, the annular groove 108 is formed in the radial lug 93. It has a U-shaped axial section and its opening opens onto the peripheral annular face 105 of the radial lug 93.Due to the radial notches formed in the radial lug 93, the latter is in the form of several sectors of radial lugs which comprise portions of the annular groove. In this way, the fourth ring 107 extends downstream of the third ring 101 and into the radial notches 104. The fourth ring 107 is advantageously arranged opposite the downstream faces of the teeth. Advantageously, the third ring 101 comprises means for axially immobilizing the fourth ring 107. Indeed, the third ring 101 advantageously comprises two protrusions 106 which each extend, along the longitudinal axis X, from a downstream face 103b of a radial tooth 103 of the third ring 101. The radial teeth 103 carrying the protrusions 106 are located opposite each other. In other words, these radial teeth 103 are diametrically opposed. In the present example, each protrusion 106 has an L-shaped axial section. Each protrusion 106 advantageously comprises a first portion extending axially from the downstream face and a second portion extending from one end of the first portion towards the longitudinal axis X. In this way, the second portion is at a distance from the downstream face 103b of the radial tooth 103. In the installation situation, when the downstream faces 103b of certain radial teeth 103 are in contact with the downstream face 93a, the protrusions 106 are engaged in corresponding radial notches 104 and the fourth ring 107 is received in the space formed between the downstream face of the radial tooth 103 and the upstream face of the second portion of the protrusion 106. Advantageously, but not limitingly, the protrusions 106 are engaged in the respective notches after a rotation of the third ring 101. The locking device 42 advantageously comprises a locking element 110 configured so as to immobilize the first nut 60 and the third nut 90 in position. Advantageously, but not limitingly, the locking element 110 is engaged with the first nut 60 and the second nut 73. More precisely, the locking element 110 comprises a cylindrical shape with an axis of revolution centered on the longitudinal axis. 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 each extend along the axis of revolution of the locking element 110 and are regularly distributed around the axis of revolution. According to another advantageous characteristic, the locking element 110 also comprises second external splines 113 which engage 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 each extend along the axis of revolution of the locking element 110 and are regularly distributed around the axis of revolution. Advantageously, but not limitatively, the first external grooves 111 and the second external grooves 113 are axially offset. Alternatively, the locking element 110 is screwed onto a thread of the first nut 60 and the third nut 90. In this case, the locking element 110 comprises external threads cooperating respectively with internal threads of the first and second nuts. In the present example, the locking element 110 comprises a first portion 115a and a second portion 115b which have different sections. In particular, the internal diameter of the second portion 115b is smaller than the internal diameter of the first portion 115a. The first and second portions 115a, 115b are separated by a shoulder 115c. Figures 4 to 16 illustrate steps for assembling the turbomachine modules. We understand that the assembly or reassembly of the turbomachine modules can be used by repeating these operations in reverse order. As illustrated in [Fig. 4], a first step of the method consists of installing the first nut 60 in the low-pressure compressor shaft 15. The first nut 60 is inserted from the upstream end 1Sa of the low-pressure compressor shaft 15. The first nut 60 is moved in translation along the longitudinal axis until at least a portion of the downstream annular face 62b of the collar 62 bears against the upstream annular surface 51a of the annular projection 51. The first nut 60 is thus captive on the low-pressure compressor shaft 15. The method comprises a second step of tightening the low pressure shaft 9 onto the first nut 60 (the latter being captive in the low pressure compressor shaft 15). For this purpose, 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 makes it possible to secure the low pressure shaft 9 to the low pressure compressor shaft 15. In Figures 5 and 6, the method comprises a third step of limiting the translation of the first nut 60. The translation limitation is achieved by means of the anti-displacement member 65. This step comprises the engagement of the anti-displacement member 65 in the low-pressure compressor shaft 15. The anti-displacement member 65 is moved in translation along the longitudinal axis so as to take it from a disengagement position to a position of engagement with at least the low-pressure compressor shaft 15. In this engagement position of the anti-displacement member 65, the teeth 68 are engaged in the notches 70 of the low-pressure compressor shaft 15 and the downstream face 67b of the annular wing 67 of the anti-displacement member 65 is opposite the upstream annular face 62a of the collar 67 of the first nut 60.In this way, the first nut 60 cannot move along the longitudinal axis X upstream (or at least over a short distance corresponding to the axial clearance J1) but can still pivot. In particular, the teeth 68 allow at least part of the axial clearance J1 to be created, allowing the first nut 60 to rotate freely. With reference to Figures 7 and 8, the method comprises a fourth step which consists of axially immobilizing the anti-displacement member 65. This makes it possible to maintain the anti-displacement member 65 so that it axially limits the first nut 60 upstream. For this, this fourth step comprises a sub-step of screwing the second nut 73 onto the low-pressure compressor shaft 15. In this way, the second nut 73 is taken from an unscrewing position to a screwing position. This screwing step is carried out using another suitable tool (not shown) which is also inserted inside the low-pressure compressor shaft. The second nut 73 is screwed until it is axially tightened against the anti-displacement member 65. In the screwing position, the internal and external threads 74, 76 are engaged and the second annular face 74b of the second nut 73 bears against the upstream face 67a of the annular wing 67 of the anti-displacement member 65.The low pressure compressor shaft 15 can no longer move backward downstream, nor can the low pressure compressor (i.e. the second nut 73) prevent the low pressure compressor and the low pressure turbine from coming together. The method also comprises a fifth step which consists of locking the second nut 73 in rotation. The method comprises for this purpose a sub-step in which the first locking system 77 is mounted. Advantageously, the first locking system 77 is a nut brake. Of course, other means having the same function are conceivable. In a first step, the first ring 78 is brought from a disengagement position to an engagement position. In passing from one to the other of the positions, the radial teeth 82 axially pass through the slots 81 of the second nut 73 and also the radial notches 84 arranged radially outside the second nut 73. The second nut 73 is screwed in such a way that the slots are respectively opposite the radial notches 84.In this way, the first ring 78 extends through both the first nut 60 and the low pressure compressor shaft 15 so that the radial teeth 84 cannot rotate about 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. The first ring 78 extends radially around the anti-displacement member 65. In a second step, the second ring 85 is brought from a disengaged position to an engaged position as well. In the engaged position, the second ring 85 is inserted into the annular groove 87 of the second nut 73. The radial teeth are axially locked by the second ring 85. Referring to [Fig. 10], the method comprises a sixth step of installing the third nut 90 onto the input shaft 12. The third nut 90 is inserted from the downstream end 12b of the input shaft 12 from downstream to upstream. The third nut 90 is then located in the cavity 91 of the input shaft 12. Installation is possible due to the external diameter of the annular sole 94 being smaller than the internal diameter of the input shaft 12 measured at the peripheral annular face 105 of the radial lug 93. The third nut 90 is put on hold after its insertion into the cavity 91. With reference to Figures 11 and 12, the method comprises a seventh step of trapping the third nut 90 in the cavity 91. For this, the seventh step comprises a sub-step in which the third ring 101 is mounted on the input shaft 12. The third ring 101 is taken from a disengaged position to an engaged position. When moving from one position to the other, the third ring 101 is positioned so that the radial teeth 103 axially pass through the radial notches 104. Once the third ring 101 is in the cavity 91, it is pivoted as in [Fig. 12] so that the radial teeth 103 are no longer opposite the radial notches 104. In the engagement position, the downstream faces 103b of the teeth are opposite the upstream face 93a of the radial lug 93. The downstream face 94b of the third nut 90 is also opposite the upstream face 101a of the third ring 101 against which the latter is intended to bear.The internal diameter of the ring 101 is smaller than the external diameter of the annular sole 94 and the third ring 101 is intended to extend around the cylindrical body of the third nut 90. This configuration makes it possible to reduce the radial opening at the downstream end 15b of the input shaft 12 delimited by the peripheral annular face 105, which prevents the extraction of the third nut 90 downstream. The internal diameter of the third ring 101 being smaller than the internal diameter of the lug 93 (delimited by the annular surface 105), the contact surface with the third ring 101 is larger. The third nut 90 is enclosed or trapped in the cavity 91. Referring to [Fig. 14], the method comprises an eighth step consisting of trapping the third ring 101 in the cavity 91. For this, the method comprises a sub-step in which the fourth ring 107 is taken from a disengagement position to an engagement position. In the engagement position, the fourth ring 107 is inserted into the annular groove 108 of the input shaft 12. The radial teeth 103b are axially blocked by the fourth ring 107. More precisely, the third ring 101 cannot move axially downstream. With reference to [Fig. 15], the method comprises a ninth step consisting of securing the input shaft 12 to the low-pressure compressor shaft 15. For this, 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 using the splines 47, 49. In this way, the input shaft 12 is also taken from a disengaged position to a disengaged position. In the engagement position, the splines 47, 49 are engaged and the downstream face 93b of the downstream end 12b of the input shaft 12 bears against the annular surface 86 of the low pressure compressor shaft 15. With reference to [Fig. 16], the method comprises a tenth step consisting of screwing the third nut 90. In this way the third nut 90 is taken from an unscrewing position to a screwing position. This screwing step is carried out using a suitable tool (not shown) which is also inserted inside the input shaft 12 of the speed reducer 3 from upstream. The third nut 90 is screwed until it is axially tightened against the third ring 101. In the screwing position, the external thread 95 of the third nut 90 is engaged 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 bears against the upstream face 101a of the third ring 101. Finally, the method comprises an eleventh step of engaging the locking element 110. The locking element 110 is moved from a disengaged position to an 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) which is also inserted inside the input shaft 12 from upstream. In the engaged position, the first external splines of the locking element 110 are engaged with the internal splines 112 of the first nut 60 and the second external splines 113 of the locking element 110 are engaged with the internal splines 114 of the third nut 90. The locking element 110 prevents the first and second nuts from loosening or unscrewing. With such a configuration, it is possible to disassemble and assemble only the input shaft 12 of the speed reducer 3 while maintaining the other shafts of the modules in the assembled position. The various nuts 60, 73, 90 and the members (rings, anti-displacement member and locking elements) are tightened on each other to perform, on the one hand, anti-rotation functions and, on the other hand, anti-axial displacement functions. The low pressure compressor shaft 15 is independent of the input shaft 12 and the low pressure shaft 9. By dismantling the input shaft 12, the low pressure shaft 9 remains integral with the low pressure compressor shaft 15 via the first nut 60, the anti-displacement member 65 and the second nut 73.
Claims
Claims
1. Turbomachine (1), in particular for an aircraft, the turbomachine (1) having a longitudinal axis (X) and comprising: - a first module (11) comprising a speed reducer (3) which comprises an input shaft (12) centered on the longitudinal axis (X), - a second module (14) comprising a low pressure compressor (4), the second module (14) being connected to the first module (11), - a third module (16) comprising a low pressure shaft (9) which is centered on the longitudinal axis X, the low pressure shaft (9) comprising an upstream end (9a) connected to the input shaft (12), and - a locking device (42) configured to immobilize axially the third module (16) relative to the first module (11), characterized in that the locking device (42) is configured in so as to axially immobilize the second module (14) relative to to the first module (11) and to the third module (14) and includes: - a first nut (60) which is screwed onto a thread of the upstream end (9a) of the low pressure shaft (9) and bearing against an annular projection (51) of the second module (14), - an anti-displacement member (65) which is configured so as to limit axially the displacement of the first nut (60), - a second nut (73) which is screwed onto a thread of the second module (14) and which is configured so as to axially immobilize the anti-displacement member (65), and - a third nut (93) which is screwed onto the anti-displacement member (65).
2. Turbomachine according to the preceding claim, characterized in that the locking device (42) comprises a locking element (110) cooperating with the first nut (60) and the third nut (90).
3. Turbomachine (10) according to one of the preceding claims, ca- characterized in that the first nut (60) is mounted to rotate freely around the longitudinal axis (X).
4. Turbomachine (1) according to one of the preceding claims, ca- characterized in that the second module (14) comprises a shaft of low pressure compressor (15) which is connected to the low pressure compressor pressure (4) and which is centered on the longitudinal axis (X), the com- low pressure presser (15) being connected to the input shaft (12) and to the shaft low pressure (9).
5. Turbomachine (1) according to the preceding claim, characterized in that that the low pressure compressor shaft (15) includes the projection annular (51) and the first nut (60) has a downstream face (62b) in support against an upstream face (51a) of the annular projection (51).
6. Turbomachine (1) according to one of claims 4 and 5, characterized in that the anti-displacement member (65) comprises a plurality of teeth (68) each intended to engage in a notch (70) of the shaft of low pressure compressor (15).
7. Turbomachine (1) according to the preceding claim, characterized in that the plurality of teeth (68) has an outer diameter greater than a external diameter of a collar (62) of the first nut (60).
8. Turbomachine (1) according to any one of the preceding claims- preceding, characterized in that the second nut (73) is intended to be locked in rotation by a first locking system (77).
9. Turbomachine (1) according to claims 4 and 8, characterized in that the first locking system (77) comprises: - a first ring (78), centered on the longitudinal axis (X) and intended to come to bear against a radial annular face (74a) of the second nut (73), the first ring (78) comprising a plurality of teeth radials (82) each intended to engage in a radial notch (84) of the low pressure compressor shaft (15), and - a second ring (85), centered on the longitudinal axis (X) and received in an annular groove (87) of the second nut (73), the groove annular (87) being arranged upstream of the radial annular face (74a).
10. Turbomachine according to one of the preceding claims, characterized in that it comprises a second locking system (100) configured to enclose the third nut (90) in a cavity annular (91) of the input shaft (12).
11. Turbomachine (1) according to the preceding claim, characterized in that that the second locking system (100) comprises: - a third ring (101), centered on the longitudinal axis (X), and comprising a plurality of radial teeth (103) which have laces downstream (103b) intended to bear against an annular face (93a) of the input shaft (12), the third ring (101) comprising a face upstream (101a) against which abuts a downstream face (94b) of the third nut (90), and - a fourth ring (107), centered on the longitudinal axis (X), received in an annular groove (108) of the input shaft (12), the fourth ring (107) being opposite the downstream faces (103b) of the radial teeth (103).
12. Turbomachine (1) according to any one of the preceding claims- preceding, characterized in that the first module (11) comprises a blower (2) which is connected to a blower shaft (13) and which is arranged upstream of the second module (14), the low pressure shaft (9) rotating the fan shaft (13) via the speed reducer (3).
13. Turbomachine (10) according to claim 12, characterized in that the blower (2) is shrouded.
14. Method of mounting a turbomachine according to one of the claims preceding, characterized in that it comprises the steps of: - screwing the first nut (60) onto the low pressure shaft (9), - translation limitation of the first nut (60) on the com- shaft low pressure presser (15) along the longitudinal axis by means of the anti-displacement organ (65), - axial immobilization of the anti-displacement member (65) by means of the second nut (73), - screwing the third nut (90) onto the anti-displacement member (65).
15. Method according to claim 14, characterized in that it comprises a step of engaging a locking element (110) on the third nut (90) and on the first nut (60).