AXIAL ALIGNMENT SYSTEM OF A ROTARY SHAFT OF A FIRST ELEMENT WITH RELATION TO A ROTARY SHAFT OF A SECOND ELEMENT OF A TURBOMACHINE

Abstract

The invention relates to an axial alignment system of a rotating turbine shaft (36) relative to a rotating compressor shaft (38) in a turbomachine, the two rotating shafts (36, 38) being coaxial. The axial support system comprises: - an axial retaining device downstream of the turbine rotating shaft (36), the downstream axial retaining device being fixed to the rotating shaft (36) and bearing axially on a support element (38b) of the compressor rotating shaft (38) which forms a downstream axial stop for the rotating shaft (36); - an axial retaining device upstream of the turbine rotating shaft, the upstream axial retaining device being fixed to the compressor rotating shaft (38) and comprising an upstream axial retaining element (44) for an upstream end (36a) of the turbine rotating shaft (36). Fig. 4

Description

Title of the invention: SYSTEM FOR AXIALLY LOCKING A ROTATING SHAFT OF A FIRST ELEMENT WITH RESPECT TO A ROTATING SHAFT OF A SECOND ELEMENT OF A TURBOMACHINE Technical field

[0001] The present disclosure relates to a system for axially locking a rotary shaft of a first element, in particular a turbine, in particular a low-pressure turbine, relative to a rotary shaft of a second element, in particular a compressor, in particular a low-pressure compressor of a turbomachine. Prior art

[0002] Aircraft turbomachine arrangements are known in which a system is provided for axially locking a low-pressure turbine rotating shaft relative to a low-pressure compressor rotating shaft which is mounted coaxially around the turbine rotating shaft.

[0003] Such an axial shim system is produced in the form of a shim whose dimensions vary according to certain specific dimensions of the engine in which the shim is to be installed. It is only after having measured these different dimensions, during the assembly of the different constituent modules of the engine, that the shim can be sized and then machined.

[0004] Alternatively, it is possible to have a set of shims with dimensions axial dimensions go for example from 0.1mm to 0.1mm in order to choose the appropriate shim from this set of shims, as soon as the shim has been sized after taking the different dimensions.

[0005] However, this alternative requires having a large number of shims since the tolerance interval where the shim is likely to be found is greater than one millimeter.

[0006] The arrangements described above and the associated methods prove to be complicated to implement and time-consuming. Statement of the invention

[0007] In view of the above, it would be desirable to envisage a new system for axially locking a rotary shaft of a first element, in particular of a turbine, relative to a rotary shaft of a second element, in particular of a compressor, in a turbomachine which is simpler to implement than in the prior art, as well as an associated axial locking method.

[0008] The invention thus relates to a system for axially locking a first turbomachine element relative to a rotary shaft of a second turbomachine element, the turbomachine being configured to be traversed by a flow of fluid F flowing from upstream to downstream in an axial direction XX', the two rotary shafts being coaxial, characterized in that the axial locking system comprises: -a device for axially retaining the rotary shaft of the first element downstream of the rotary shaft, the device for axially retaining the rotary shaft downstream, on the one hand, being fixed to the rotary shaft of the first element and, on the other hand, bearing axially on a support element of the rotary shaft of the second element which forms a downstream axial stop for the rotary shaft of the first element, -an upstream axial retaining device for the rotary shaft of the first element, the upstream axial retaining device, on the one hand, being fixed to the rotary shaft of the second element and, on the other hand, comprising an upstream axial retaining element for an upstream end of the rotary shaft of the first element.

[0009] The aforementioned configuration makes it possible to do without an axial shim and, therefore, also makes it possible to avoid having to take different axial measurements or dimensions prior to dimensioning the shim for a given engine configuration. The two axial retaining devices downstream of the rotary shaft of the first element (e.g. turbine) and upstream of the rotary shaft of the first element make it possible to axially secure the two shafts to each other as soon as the rotary shaft of the first element is positioned axially relative to the stator of the first element, without having to take any prior measurements. This also results in a saving of time in setting up the axial shim system.

[0010] According to other possible characteristics: -the axial retention device downstream of the rotary shaft of the first element comprises a fixing portion which is fixed to the upstream end of the rotary shaft of the first element; -the support element of the rotary shaft of the second element comprises a shoulder which extends radially from the rotary shaft of the second element towards the rotary shaft of the first element; - the fixing part fixed to the upstream end of the rotating shaft of the first element bears axially on the radial shoulder; -the fixing portion fixed to the upstream end of the rotating shaft of the first element is a clamping nut which is tightly mounted on an external surface of the upstream end of the shaft of the first element; -the axial retention device downstream of the rotary shaft of the first element further comprises an anti-rotation device configured to prevent the tightening nut from rotating; -the axial retaining device upstream of the rotary shaft of the first element comprises a covering piece which is fixed to the rotary shaft of the second element; -the cover piece fixed to the rotary shaft of the second element comprises, on a downstream side, a flange which is fixed to the rotary shaft of the second element and, on an upstream side, a disc which extends radially opposite the upstream end of the rotary shaft of the first element in order to form the upstream axial retaining element for the upstream end of the rotary shaft of the first element; -the covering piece fixed to the rotary shaft of the second element has a general hat shape which axially and radially covers the upstream end of the rotary shaft of the first element and the flange of the covering piece extending radially, away from the rotary shaft of the first element, and being fixed against a radial face of the rotary shaft of the second element; - the flange of the covering part is fixed, by means of one or more axial fixing members, on the radial face of the part of the rotary shaft of the second element, the radial face of the part of the rotary shaft of the second element being arranged downstream of the flange of the covering part; -the rotating shaft of the first element and the rotating shaft of the compressor are rotationally coupled; -the first element is a turbine and the second element is a compressor; -the turbine is a low pressure turbine and the compressor is a low pressure compressor; -the first element is a compressor and the second element is a blower.

[0011] The invention also relates to a turbomachine comprising a system for axially locking a rotary shaft of a first element (e.g. turbine) relative to a rotary shaft of a second element (e.g. compressor) as briefly explained above.

[0012] The invention also relates to a method for axially locking a rotary shaft of a first element (e.g.: turbine) of a turbomachine relative to a rotary shaft of a second element (e.g.: compressor) of a turbomachine, the turbomachine being configured to be traversed by a flow of fluid F flowing from upstream to downstream in an axial direction, the method comprising the following steps: - SI installation of a rotor of a first element comprising a rotating shaft of the first element in a turbomachine, - maintaining S2 an axial position of the rotor of the first element relative to a stator of the first element in the turbomachine using a temporary axial positioning tool Op between the rotor of the first element and the stator of the first element, - S3-S5 assembly of an axial retaining device downstream of the rotating shaft of the rotor of the first element by fixing the downstream axial retaining device to the rotating shaft of the rotor of the first element and resting the downstream axial retaining device on a support element of a rotating shaft of a rotor of the second element which forms a downstream axial stop for the rotating shaft of the rotor of the first element, -mounting S6-S7 of an axial retaining device upstream of the rotary shaft of the first element by positioning, upstream and opposite an upstream end of the rotary shaft of the rotor of the first element, an axial retaining element of the axial retaining device upstream and by fixing the axial retaining device upstream to the rotary shaft of the rotor of the second element.

[0013] The method allows axial wedging to be carried out simply and quickly, thus avoiding the tedious methods of the prior art. This method has the same advantages and characteristics as the system described above and they will therefore not be repeated here. Brief description of the drawings

[0014] Other characteristics and advantages of the subject of the present disclosure will emerge from the following description of embodiments, given as non-limiting examples, with reference to the appended figures.

[0015] [Fig-1] [Fig.l] is a general schematic view in axial section of a tur- aircraft engine according to one embodiment of the invention;

[0016] [Fig.2] [Fig.2] is a view of a flowchart detailing different stages of a method of axially locking a rotating turbine shaft relative to a rotating compressor shaft in the turbomachine of [Fig.l] according to one embodiment of the invention;

[0017] [Fig.3] [Fig.3] is a schematic general view illustrating a positioning relative axial between a rotating turbine rotor shaft and a stator of the turbine;

[0018] [Fig.4] [Fig.4] is an enlarged schematic view in longitudinal section of a possible embodiment of the axial timing of a rotating turbine shaft relative to a rotating compressor shaft in the turbomachine of [Fig.l];

[0019] [Fig.5] [Fig.5] is a schematic exploded perspective view of the arrangement of [Fig.4] representing the upstream part of the compressor shaft;

[0020] [Fig.6] [Fig.6] is a view similar to that of [Fig.4] of a variant of the sheave lization of the mode of [Fig.4];

[0021] [Fig.7] [Fig.7] is an enlarged schematic view in longitudinal section of a possible embodiment of the axial timing of a compressor rotating shaft relative to a fan rotating shaft in the turbomachine of [Fig.l];

[0022] [Fig.8] [Fig.8] is a schematic exploded perspective view of the arrangement of [Fig.7];

[0023] [Fig.9] [Fig.9] is a perspective view similar to that of [Fig.8] but in assembled mode. Detailed description

[0024] [Fig. 1] schematically illustrates in a longitudinal section an aircraft turbomachine 10 such as a dual-flow turbojet according to one embodiment of the invention. Other types of turbomachines can alternatively be envisaged.

[0025] The turbomachine 10 comprises here, from upstream to downstream according to the circulation of the air flow F in the turbomachine (from left to right in the figure), a fan 12, a low-pressure compressor 14, a high-pressure compressor 16, a combustion chamber 18, a high-pressure turbine 20 and a low-pressure turbine 22. All these elements exert their action in a known manner on a first annular air flow circulating in a first central duct 24 coaxial with the longitudinal axis XX' of the turbomachine. A second annular bypass duct 26 concentrically surrounds the first central duct 24 for the flow of a second annular air flow. Other turbojet configurations can alternatively be envisaged with a single compressor and a single turbine, or even with more than two compressors and more than two turbines.

[0026] We will now describe with reference to Figures 2 to 6, a method of axially locking a rotary shaft of a first element of the turbomachine, here a turbine, in particular a turbine rotor, relative to a rotary shaft of a second element of the turbomachine, here a compressor, in particular a compressor rotor, according to one embodiment of the invention.

[0027] [Fig.2] is a flowchart illustrating the possible steps of such a method.

[0028] [Fig. 3] schematically represents a turbine of the turbomachine of [Fig. 1], for example the low pressure turbine 22, in particular in its downstream part. This turbine comprises a stator 32 mounted coaxially around a central rotor 34 which comprises a rotary shaft 36 extending upstream of the turbomachine. A possible example of the rotary shaft 36 is illustrated in more detail in the following figures and in particular its upstream part.

[0029] The method comprises a first step S1 which takes place, for example, during the assembly of the various modules or components of the turbomachine. This step can alternatively be carried out during a maintenance operation on the turbomachine. During this step, the turbine rotor 34 is placed in the turbomachine relative to the stator 32 of the turbine.

[0030] During a following step S2, the axial positioning of the rotor is carried out. turbine 34 relative to the stator 32 of the turbine. This positioning is carried out using a temporary axial positioning tool Op between the downstream part of the turbine rotor 34 and the turbine stator 32 (on the right of [Fig.3]), the turbine rotor coming to rest against this tool ([Fig.2]). This position is determined so that the stator and the rotor do not come into contact with each other. A tolerance interval can be defined from a chain of dimensions. This thus makes it possible to ensure that the axial position of the rotor 34 of the turbine is maintained relative to its stator 32.

[0031] As shown in more detail in [Fig. 4], the rotating turbine shaft 36 is engaged by its upstream end 36a inside a compressor shaft 38 of which only a part 38a is shown in this figure. The compressor concerned is for example the low pressure compressor 24 of the turbomachine of [Fig. 1]. The part 38a of [Fig. 4] is coaxially crossed by the upstream end 36a of the rotating turbine shaft 36.

[0032] In this embodiment, the free upstream end 36a of the turbine shaft is provided with teeth distributed regularly over its entire circumference. In [Fig. 4], only the space between two consecutive teeth is visible. The teeth referenced 36al are shown in [Fig. 5] described below.

[0033] The compressor rotor shaft 38 is axially wedged downstream on the compressor stator (not shown) in a known manner, for example by means of a ball bearing (not shown).

[0034] A rotary shaft 37 is arranged coaxially and internally to the rotary turbine shaft 36 and is axially and rotatably secured thereto by specific means. The shaft 37 allows air to be evacuated downstream from the bearing enclosure, thereby protecting the turbine shaft 36 from possible coking. More particularly, the rotary shaft 37 has a free upstream end 37a which is provided with fingers 37al (two fingers are visible in [Fig. 4] and three are visible in [Fig. 5]; this number may however differ) which each engage in a free space between two teeth 36al. This arrangement makes it possible to lock the shaft 37 in rotation relative to the shaft 36. Furthermore, an arrangement 39 formed for example by an annular collar 39a on the internal face of the shaft 36 is engaged in a groove 39b formed between two circular projections on the external face of the shaft 37.This arrangement makes it possible to axially lock the shaft 37 relative to the shaft 36.

[0035] When the upstream end 36a of the turbine rotary shaft 36 is in the engaged configuration inside the compressor shaft 38 ([Fig.4]) with the downstream end of the turbine rotary shaft 36 in an axial position determined by the temporary tooling Op, the method comprises a following step S3.

[0036] During this step S3, a first part 40 or fixing part of an axial retaining device downstream, or said downstream, of the rotary shaft of turbine 36 on the upstream end 36a thereof. More particularly, this first part 40 is mounted around the upstream end 36a of the shaft ([Fig.4]). During this assembly, the part 40 comes into axial support against one or more support elements 38b of the compressor shaft 38 which form a downstream axial stop. A single support element 38b will be considered below for the sake of simplicity, but this does not exclude the possibility of there being several, for example distributed circumferentially on the internal surface of the shaft. The support element 38b here takes the form of a radial shoulder which extends radially (in a plane transverse to the longitudinal axis XX') from the internal surface of the part 38 in the direction of the facing rotating turbine shaft 36 (the two shafts are coaxial).The support element 38b forms a second part of the downstream axial retaining device of the turbine rotating shaft 36 and makes it possible, together with the first part 40 (when the latter is fixed to the turbine rotating shaft 36), to prevent any axial movement towards the downstream side of the turbine rotating shaft 36, i.e. from left to downstream in the drawings.

[0037] This first part 40 is illustrated in particular in the exploded view of [Fig. 5] which illustrates in particular in perspective an upstream end 38a of the compressor rotary shaft 38 and an inner part of this shaft. The first part 40 of [Fig. 5] is formed here by a large diameter tightening nut since it is mounted around the upstream end 36a of the turbine rotary shaft. The nut 40 comprises at one of its two opposite ends, the one directed upstream, teeth 40a distributed circumferentially in a regular manner and which extend axially in the extension of the cylindrical part of the general shape of the nut. The opposite downstream end 40b of the part 40 is smooth and forms a bearing surface which comes into contact with the aforementioned bearing element 38b. During the following step S4 the first part 40 is fixed on the upstream end 36a. Here, the clamping nut 40 is tightened onto a threaded external surface of the upstream end 36a.

[0038] After the fixing step S4, the method comprises a step S5 during which a device for locking the first part 40 is put in place. In practice, in the case of the clamping nut 40, this is a device 42 for locking the clamping nut against rotation (figs. 4 and 5), also called an anti-rotation device. More particularly, the anti-rotation device 42 is positioned at the upstream end 36a by being introduced inside the nut 40. This device takes the form of a part, for example in the form of a disc, provided at its periphery with several locking members 42a 1, 42a2 forming fingers which extend radially away from the part ([Fig.5]).Thus, when the part 42 is inserted inside the nut 40, the locking fingers 42al, 42a2 are engaged between two consecutive teeth 40a of the nut and between the teeth of the upstream end 36a of the turbine shaft, which makes it possible to lock the nut in rotation relative to the upstream end 36a on which it is mounted tightly. In this example, one of the fingers, 42a 1, has a greater radial extension than the other fingers 42a2 and it engages between two consecutive teeth 40a, while the other fingers 42a2 each engage between two consecutive teeth 36al.

[0039] In the example described, four locking fingers are arranged at the periphery of the part 42 with three fingers 42a2 in the lower part and a fourth diametrically opposite one, 42al, arranged in the upper part to distribute the masses. A different number of fingers can however be envisaged.

[0040] The first part 40 (e.g.: tightening nut) fixed to the rotating turbine shaft 36, the support element 38b (e.g.: shoulder or radial internal axial stop) of the compressor shaft and the anti-rotation device 42 together form an example of a possible embodiment of a downstream axial retaining device for the rotating turbine shaft 36 which has just been mounted according to steps S3-S5.

[0041] During a following step S6, a part 44 (re-covering part) of an axial retaining device towards the upstream, or so-called upstream, of the turbine rotary shaft 36 is placed on the upstream end 36a of this shaft so as to form an upstream axial retaining element for the upstream end 36a.

[0042] During a following step S7, the part 44 is fixed to the compressor rotary shaft 38, thus ensuring the upstream axial locking of the turbine rotary shaft 36 which is thus prevented from moving downstream and upstream.

[0043] Generally, the part 44 comprises, on the one hand, on a downstream side, a first part or flange 44a which is fixed to the compressor rotary shaft 38 and, on the other hand, on an upstream side, a second part or disc 44b which is shaped so as to extend both axially upstream and radially opposite the upstream end 36a of the turbine rotary shaft 36 (and opposite the upstream end 37a of the coaxial internal shaft 37) in order to form the upstream axial retaining element mentioned above for the upstream end 36a of the turbine rotary shaft 36.

[0044] More particularly, in the example illustrated in Figures 4 and 5, the covering part 44 (plate) has a general shape of a cap or cover comprising, on the one hand, a central part 44b (disc) forming the second part of the part and axially and radially covering the upstream end 36a of the rotating turbine shaft 36 and, on the other hand, an annular edge 44a (flange), forming the first part of the part and extending radially, away from the rotating turbine shaft 36, against an (internal) radial (upstream) face 38c of a part of the rotating compressor shaft 38. The central part 44b is here pierced axially in its center so as to form a crown, which leaves free axial access to the interior of the internal shaft 37 in order to allow the air to escape downstream through tree 37.

[0045] As shown in [Fig.4], the central part 44b of the part 44 covers the upstream end 36a and the annular edge 44a bears axially against the face upstream, transverse (radial) 38c of the compressor rotating shaft 38.

[0046] The upstream end wedging part 44 is fixed to the compressor rotary shaft 38 by means of one or more fixing members 46 which ensure the fixing, for example, of the annular edge 44a (flange) on the transverse upstream face 38c of the compressor rotary shaft. These are for example fixing members (e.g. screws) which ensure the fixing by clamping of the part 44 on the compressor rotary shaft 38. There are here several fixing members 46 ([Fig.4]) which pass through the annular edge 44a in its thickness as well as the facing part 38c of the compressor rotary shaft. As shown in [Fig.5], the annular edge 44a is pierced with holes 44c regularly distributed around its circumference and which are arranged in geometric correspondence with axial holes 38d made in the transverse upstream face 38c.An annular ring, not shown, may be interposed between the locking device 42 and the end piece 44 and serves to axially lock the device 42 used to lock the rotation of the nut 40.

[0047] It will also be noted that the central part 44b (disc) pierced axially in its center has, more particularly, a central conformation taking the form of an axial annular rim 44d externally bordering the central hole O. This rim 44d comes to bear against the anti-rotation device 42 (e.g.: nut lock ring) in order to keep it axially in position against the part 40 (nut). Thus, it is possible to do without a stop ring (not shown) constituting an additional part and ensuring the same axial stop function.

[0048] [Fig. 4] illustrates the assembly formed by the turbine rotary shaft 36 and the assembled compressor rotary shaft 38 and the turbine rotary shaft 36 axially wedged along the longitudinal axis XX', in particular thanks to the upstream end wedge part 44.

[0049] The part 44 fixed to the compressor rotary shaft 38 by one or more fixing members 46 and its cover shape for the upstream end 36a jointly form a possible embodiment of the upstream axial retaining device of the turbine rotary shaft 36 which has just been mounted according to steps S7 and S8.

[0050] During a subsequent step S8, the temporary positioning tool OP of [Fig.2] can be disassembled because the rotor shaft 36 of the turbine has been axially wedged as explained above.

[0051] According to an alternative embodiment illustrated in [Fig. 6], the upstream end wedging part is no longer necessary. This is made possible by a modification of the part 40, here denoted 40', which has, in addition to its generally cylindrical nut shape 40'b provided with teeth 40'a (identical to the teeth 40a) which extend axially relative to the generally cylindrical shape of the nut, an annular flange 40'c. The annular flange 40'c comes into contact with the transverse upstream face 38c of the compressor shaft 38. Fastening members 46 identical to the members 46 of FIGS. 4 and 5 pass through the flange 40'c in its thickness and engage in axial holes 38d as in [Fig.4], thus axially securing the part 40' to the compressor shaft 38 and forming an upstream axial stop for the turbine shaft 36. The weight of the assembly with one less part can therefore be reduced and the axial wedging operations are thus facilitated.

[0052] Figures 7 to 9 illustrate another embodiment of axial timing of a first element of the turbomachine relative to a second element of the turbomachine. The first element of the turbomachine is a compressor, in particular a compressor rotor, and the second element of the turbomachine is a fan, in particular a fan rotor (fan 12 of [Fig. 1]). The compressor concerned is for example the low-pressure compressor of the turbomachine of [Fig. 1].

[0053] Since the part of the compressor shaft which will be described in this embodiment is different from that illustrated in [Fig. 5], the references of this part will be preceded by the number '1' compared to the references of figures 4 and 5.

[0054] As shown in more detail in [Fig. 7], the rotary compressor shaft 138 is engaged by its upstream end 138a inside a fan rotor shaft 12a according to a method of axially wedging the rotary shaft of the compressor 138 relative to the fan rotor 12a. The fan rotor shaft 12a comprises a hub which is coaxially traversed by the upstream end 138a of the rotary compressor shaft 138. The part of the rotary shaft 138 engaged inside the hub 12a carries, on its external surface, rotational engagement means 138b (e.g.: longitudinal splines) which are intended to cooperate with complementary means 12al (e.g.: axial ribs) provided on the internal surface of the hub ([Fig. 7]) and which jointly ensure rotational coupling of the two parts.

[0055] Generally, the hub 12a is provided with grooves parallel to each other and to the longitudinal axis XX', arranged circumferentially on the external surface of the part 38 and defining between them, two by two, cells intended to receive the fan blades shown in [Fig.l].

[0056] According to the axial wedging method, a first part or fixing part 140 of an axial retaining device downstream or said downstream, of the compressor rotary shaft 138 is put in place on the upstream end 138a thereof. More particularly, this first part 140 is mounted around the upstream end 138a of the shaft. During this mounting, the part 140 comes into axial support against one or more support elements 12a2 of the fan shaft 12a which form a downstream axial stop (Figures 7 and 8). A single support element 12a2 will be considered hereinafter for the sake of simplicity but this does not exclude the possibility of there being several, for example distributed circumferentially on the internal surface of the hub 12a. The support element 12a2 here takes the form of a radial shoulder which extends radially (in a plane transverse to the axis longitudinal XX') from the inner surface of the hub towards the opposite rotary compressor shaft 138 (the two shafts are coaxial). The support element 12a2 forms a second part of the downstream axial retaining device of the rotary compressor shaft 138.

[0057] This first part 140 is illustrated in particular in the exploded view of [Fig.8] and is formed here by a large diameter tightening nut since it is mounted around the upstream end 138a of the shaft. The nut 140 has at one of its two opposite ends, the one directed upstream, teeth 140a distributed circumferentially in a regular manner and which extend axially in the extension of the cylindrical part of the general shape of the nut. The opposite downstream end 140b of the part 140 is smooth and forms a bearing surface which comes into contact with the aforementioned bearing element 12a2 when the first part 140 is mounted around the upstream end 138a. More particularly, the tightening nut 140 is mounted tightly on a threaded external surface of the upstream end 138a. It will be noted that the fixing part 140 makes it possible to produce an upstream stop of the hub 12a relative to the shaft 138.

[0058] In [Fig.8], it also appears that the upstream end 138a of the compressor shaft 138 is provided with teeth 138al distributed regularly over its entire circumference.

[0059] After the step of mounting the first part 140, a device 142 for locking the first part 140 is put in place. In practice, in the case of the tightening nut 140, this is a device 142 for locking the nut against rotation (figs. 7 and 8). More particularly, the anti-rotation device 142 is positioned at the upstream end 138a by being introduced inside the nut 140. This device takes the form of a part, for example in the form of a disc, provided at its periphery with several locking members 142a forming fingers which extend radially away from the part ([Fig.8]). Thus, when the part 142 is inserted inside the nut 140, the locking fingers 142a are engaged between two consecutive teeth 140a of the nut and between the teeth 138al of the upstream end 138a of the compressor shaft, which makes it possible to lock the nut 140 in rotation relative to the upstream end 138a on which it is tightly mounted.

[0060] In the example described, four locking fingers 142a are regularly arranged (at 90° to each other) at the periphery of the part 142 to ensure effective locking. A different number of fingers can however be envisaged.

[0061] The part 140 (e.g.: tightening nut) fixed to the rotary shaft 138 of the compressor, the support element 12a2 (e.g.: shoulder or radial internal axial stop) of the fan hub and the anti-rotation device 142 together form an example of a possible embodiment of the downstream axial retaining device of the rotary shaft of the compressor 138 which has just been mounted.

[0062] During a following step, a part 144 (covering part) of an axial retaining device towards the upstream, or so-called upstream, of the compressor rotary shaft 138 (third part of the downstream axial retaining device of the compressor rotary shaft 138) is placed on the upstream end 138a of this shaft so as to form an upstream axial retaining element for the upstream end 138a.

[0063] During a following step, the part 144 is fixed to the rotating fan shaft 12a, thus ensuring the upstream axial locking of the rotating compressor shaft 138 which is thus prevented from moving upstream. In general, the mounting of the part 144 fixed on the rotating shaft 12a and axially trapping the part 140 between the part 144 and the rotating shaft 12a ensures downstream axial locking of the compressor shaft 138 relative to the rotating shaft 12a (despite the presence of an axial clearance J between the shaft 12a and the shaft 138 in [Fig.7]).

[0064] Generally, the part 144 comprises, on the one hand, a first part 144a which is fixed to the rotating fan shaft 12a and, on the other hand, a second part 144b which is shaped so as to extend both axially upstream and radially opposite the upstream end 138a of the rotating compressor shaft 138 in order to form the upstream axial retaining element mentioned above for the upstream end 138a of the rotating compressor shaft 138 (and a downstream axial retaining element for the rotating shaft 12a).

[0065] More particularly, in the example illustrated in Figures 7 and 8, the covering part 144 (plate) has a general shape of a cap or cover comprising, on the one hand, a central part 144b (disc) forming the second part of the part and axially and radially covering the upstream end 138a of the rotary shaft 138 of the compressor and, on the other hand, an annular edge 144a (flange), forming the first part of the part and extending radially, away from the rotary shaft 138 of the turbine, against a radial (upstream) face 12a3 of a part of the rotary shaft of the fan.

[0066] As shown in [Fig.7], the central portion 144b of the part 144 covers the upstream end 138a and the annular edge 114a bears axially against the transverse (radial) face 12a3 of the rotating fan shaft 12a.

[0067] The upstream end wedging part 144 is fixed to the rotating fan shaft 12a by means of one or more fixing members 146 which ensure the fixing, for example, of the annular edge 144a on the transverse upstream face 12a3 of the rotating fan shaft 12a. These are for example fixing members (e.g. screws) which ensure the fixing by clamping of the part 144 on the rotating fan shaft 12a. There are here several fixing members 146 ([Fig.7]) which pass through the annular edge 144a in its thickness, as well as the part opposite the rotating fan shaft 12a. As shown in [Fig.8], the annular edge 144a (flange) is pierced with holes 144c regularly distributed around its circumference and which are arranged in geometric correspondence with holes 12a4 made in the transverse upstream face 12a3. An annular ring 148 is interposed between the locking device 142 and the end piece 144 and serves to axially block the piece 142 which blocks the rotation of the nut 140. It will be noted that, in a variant not shown, this ring can be removed by shaping the piece 144 with an axial annular rim which borders a central hole, in the same way as in the embodiment of [Fig.4], in order to axially hold the anti-rotation device 142 in position.

[0068] [Fig.9] illustrates the assembly formed by the rotary compressor shaft 138 and the assembled rotary fan shaft 12a and the rotary compressor shaft 138 axially wedged along the longitudinal axis XX', in particular thanks to the upstream end wedge part 144.

[0069] The part 144 fixed to the rotating fan shaft 12a by one or more fixing members 146 and its cover shape for the upstream end 138a form together with the part 140 a possible embodiment of a device for axially retaining the rotating compressor shaft 138 which has just been mounted.

[0070] According to an alternative embodiment not shown, the upstream end wedging part 144 of Figures 7 to 9 is no longer necessary. This is made possible by a modification of the part 140 similar to that of [Fig.6] in which the part 140 additionally comprises an annular flange which comes into contact with the transverse upstream face 12a3 of the rotating fan shaft 12a. The same characteristics and advantages as those of the variant of the figure apply here and will not be repeated.

[0071] Although the present description refers to specific exemplary embodiments, modifications may be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the various embodiments illustrated or mentioned may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Claims

1. A system for axially locking a rotary shaft (36; 138) of a first turbomachine element relative to a rotary shaft (38; 12a) of a second turbomachine element, the turbomachine (10) being configured to be traversed by a flow of fluid (F) flowing from upstream to downstream in an axial direction (XX'), the two rotary shafts (36, 38; 138, 12a) being coaxial, characterized in that the axial locking system comprises: - a device for axially retaining the rotary shaft (36; 138) of the first element downstream, the device for axially retaining the rotary shaft downstream, on the one hand, being fixed to the rotary shaft (36; 138) of the first element and, on the other hand, bearing axially on a support element (38b; 12a2) of the rotary shaft (38; 12a) of the second element which forms a downstream axial stop for the rotary shaft (36; 138) of the first element, - an axial retaining device towards the upstream of the rotary shaft (36;138) of the first element, the upstream axial retaining device, on the one hand, being fixed to the rotary shaft (38; 12a) of the second element and, on the other hand, comprising an upstream axial retaining element (44; 144; 40') for an upstream end (36a; 138a) of the rotary shaft (36; 138) of the first element.;

2. Axial wedging system according to claim 1, characterized in that the axial retention device downstream of the rotary shaft (36; 138) of the first element comprises a fixing part (40; 40'; 140) which is fixed to the upstream end (36a; 138a) of the rotary shaft of the first element.

3. Axial wedging system according to claim 1 or 2, characterized in that the support element (38b; 12a2) of the rotary shaft (38; 12a) of the second element comprises a shoulder which extends radially from the rotary shaft (38; 12a) of the second element towards the rotary shaft (36; 138) of the first element.

4. Axial wedging system according to claims 2 and 3, characterized in that the fixing part (40; 40'; 140) fixed to the upstream end (36a; 138a) of the rotary shaft (36; 138) of the first element bears axially on the radial shoulder (38b; 12a2).

5. Axial wedging system according to claim 2 or 4, characterized in that the fixing part fixed to the upstream end (36a; 138a) of the rotary shaft (36; 138) of the first element is a clamping nut (40; 40'; 140) which is tightly mounted on an external surface of the upstream end (36a; 138a) of the shaft (36; 138) of the first element.

6. Axial wedging system according to claim 5, characterized in that the axial retention device downstream of the rotary shaft (36; 138) of the first element further comprises an anti-rotation device (42; 142) configured to block rotation of the tightening nut (40; 40'; 140).

7. Axial wedging system according to one of claims 1 to 6, characterized in that the axial retaining device upstream of the rotary shaft (36; 138) of the first element comprises a covering part (44; 144) which is fixed to the rotary shaft (38) of the second element.

8. Axial wedging system according to claim 7, characterized in that the cover piece (44; 144) fixed to the rotary shaft (38; 12a) of the second element comprises, on a downstream side, a flange (44a; 144a) which is fixed to the rotary shaft (38; 12a) of the second element and, on an upstream side, a disc (44b; 144b) which extends radially opposite the upstream end (36a; 138a) of the rotary shaft (36; 138) of the first element in order to form the upstream axial retaining element for the upstream end (36a; 138a) of the rotary shaft (36; 138) of the first element.

9. Axial wedging system according to claim 8, characterized in that the covering part (44; 144) fixed to the rotary shaft (38; 12a) of the second element has a general hat shape which axially and radially covers the upstream end (36a; 138a) of the rotary shaft (36; 138) of the first element and the flange (44a; 144a) of the covering part extending radially away from the rotary shaft (36; 138) of the first element and being fixed against a radial face (38c; 12a3) of the rotary shaft (38; 12a) of the second element.

10. Axial wedging system according to claim 9, characterized in that the flange (44a; 144a) of the cover piece (44; 144) is fixed, by means of one or more axial fixing members (46; 146), on the radial face (38c; 12a3) of the part of the rotary shaft (38; 12a) of the second element, the radial face (38c; 12a3) of the part of the rotary shaft (38; 12a) of the second element being arranged downstream of the flange (44a; 144a) of the cover piece (44; 144).

11. Axial wedging system according to one of the preceding claims, characterized in that the rotary shaft (36; 138) of the first element and the rotary shaft (38; 12a) of the second element are rotationally coupled.

12. Axial wedging system according to one of the preceding claims, ca- characterized in that the first element is a turbine and the second element is a compressor.

13. Axial timing system according to the preceding claim, characterized in that the turbine is a low pressure turbine (22) and the compressor is a low pressure compressor (24).

14. Axial wedging system according to one of claims 1 to 11, characterized in that the first element is a compressor (24) and the second element is a blower (12).

15. Turbomachine comprising a system for axially locking a rotary shaft (36; 138) of a first element relative to a rotary shaft (38; 12a) of a second element according to one of the preceding claims.

16. Method for axially locking a rotary shaft (36) of a first turbomachine element relative to a rotary shaft (38) of a second turbomachine element, the turbomachine (10) being configured to be traversed by a fluid flow (F) flowing from upstream to downstream in an axial direction (XX'), the method comprising the following steps: - placing (SI) a rotor (34) of a first element comprising a rotary shaft (36) of the first element in a turbomachine, - maintaining (S2) an axial position of the rotor (34) of the first element relative to a stator (32) of the first element in the turbomachine using a temporary axial positioning tool (Op) between the rotor (34) of the first element and the stator (32) of the first element,- mounting (S3-S5) of an axial retaining device downstream of the rotary shaft (36) of the rotor (34) of the first element by fixing the axial retaining device downstream to the rotary shaft (36) of the rotor of the first element and placing the axial retaining device downstream on a support element (38b) of a rotary shaft (38) of a rotor of the second element which forms a downstream axial stop for the rotary shaft (36) of the rotor of the first element, - mounting (S6-S7) of an axial retaining device upstream of the rotary shaft of the first element by positioning, upstream and opposite an upstream end (36a) of the rotary shaft (36) of the rotor of the first element, an axial retaining element (44) of the axial retaining device upstream and by fixing the axial retaining device upstream to the rotary shaft (38) of the rotor of the second element.,

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