FR3007789A1 - IMPROVED COUPLING SYSTEM FOR TURBINE SHAFT WITH TURBOMACHINE DEGASSING TUBE - Google Patents

Abstract

The invention relates to an assembly comprising: - a turbine shaft, of revolution about an axis, comprising, on an inner surface, an annular portion comprising a rim, - a degassing tube of revolution adapted to extend to the interior of the turbine shaft, the tube comprising a circumferential bead, adapted to abut against the rim of the turbine shaft, characterized in that it further comprises a wedging ring disposed between the tube of degassing and the turbine shaft, said ring being held in abutment against the inner surface of the turbine shaft and against the bead of the degassing tube to ensure the coupling in rotation and in translation of the turbine shaft with the degassing tube. The invention also relates to a method of mounting such an assembly.

Description

FIELD OF THE INVENTION The subject of the present invention is an assembly comprising a turbine shaft and a turbomachine degassing tube, as well as elements ensuring their coupling in rotation and in translation, as well as a method for making such a coupling. STATE OF THE ART An example of a turbomachine has been illustrated in FIG. 10. A turbine engine 1 typically comprises a nacelle which forms an opening for the admission of a determined flow of air to the engine itself. Generally, the turbomachine comprises one or more air compression sections admitted into the engine (generally a low pressure section and a high pressure section). The air thus compressed is admitted into the combustion chamber 5 and mixed with fuel before being burned.

The hot combustion gases from this combustion are then expanded in different turbine stages. A first expansion is made in a high pressure stage 6 immediately downstream of the combustion chamber and which receives the gases at the highest temperature. The gases are expanded again by being guided through so-called low pressure turbine stages 7.

A turbine shaft, driven by the expansion of the gases in the turbine, is coupled to a compressor shaft, in order to drive in rotation the compression stages of the turbomachine. A degassing tube, also known by the acronym CVT for the English name "Center Vent Tube", extends inside the turbine shaft and recovers gases (including de-oiled air coming from bearings located in upstream relative to the air flow) to convey them to the exhaust nozzle downstream of the turbomachine with respect to the air flow. The degassing tube is integral with the turbine shaft and for this purpose, the relative rotation between the degassing tube and the turbine shaft as well as the translation of the degassing tube in the turbine shaft must be blocked. To do this, it has been proposed with reference to Figure 1 a coupling system of a turbine shaft to a degassing tube, comprising axial stop pins and P rotation installed in holes arranged in the turbine shaft and in the degassing tube, the pins for securing the shaft and the degassing tube. This system is nevertheless imperfect because the stop pins undergo significant matting efforts during the acceleration and deceleration phases of the turbomachine, which has the consequence that the pins are deformed and must be replaced. This system therefore requires frequent maintenance which represents a significant cost.

PRESENTATION OF THE INVENTION The purpose of the invention is to overcome the aforementioned problem, by proposing an assembly comprising a turbine shaft, a degassing tube, and coupling elements in rotation and in translation of these parts, whose duration of life is increased compared to the prior art.

Another object of the invention is to provide a coupling method that is easy and quick to implement. In this regard, the invention relates to an assembly comprising: - a turbine shaft, of revolution about an axis, comprising, on an inner surface, an annular portion comprising a flange, - a degassing tube of suitable revolution for extending inside the turbine shaft, the tube comprising a circumferential bead, adapted to abut against the rim of the turbine shaft, characterized in that it further comprises a setting ring , disposed between the degassing tube and the turbine shaft, said ring being held in abutment against the inner surface of the turbine shaft and against the bead of the degassing tube to ensure the coupling in rotation and in translation of the turbine shaft with the degassing tube.

Advantageously, but optionally, the assembly according to the invention further comprises at least one of the following characteristics: the bead of the degassing tube comprises flats adapted to stop a relative rotation between the tube and the turbine shaft. - The assembly further comprises a nut mounted on the degassing tube, and now bearing the ring against the turbine shaft. - The ring and the nut respectively, one an inner surface and the other an outer surface truncated cone, for cone sliding cone-cone of the ring on the nut. - The nut is screwed onto the degassing tube. - The assembly further comprises anti-rotation ring of the nut relative to the degassing tube, and an axial stop ring of said anti-rotation ring. the wedge ring comprises a plurality of ring sectors and, optionally, each ring sector comprises, on a radially external surface, a groove, and the wedging ring further comprises a circular spring adapted to be received in the ring sectors throat. the nut comprises, on its outer surface, a circumferential housing delimited axially by an upstream flange and a downstream flange, and the ring has a first portion adapted to be received in the housing and, adjacent to said portion, a circumferential protuberance forming a shoulder such that the first portion can abut against the upstream flange of the nut and the protuberance extends upstream beyond said flange, the ring and the nut being such that: o the first portion of the ring has, in an axial direction, an extension less than the extension of the housing in said direction, and o when the ring is received in the housing, abutting against the upstream collar of the nut, the upstream end of the the protuberance is offset axially with respect to the upstream flange of the nut, by a distance greater than the axial extension difference between the housing and the first portion of the housing. a ring. the turbine shaft comprises, on an inner surface, a circumferential groove delimited axially by two flanges, and the degassing tube further comprises a circumferential lug abutting against a first rim of the turbine shaft, and the ring of wedging is a split ring received in the circumferential groove, between the lug and the second flange. - The wedging ring is a ring having an outer surface of square section whose corners are chamfered. - The ring and the turbine shaft comprise dog teeth adapted to cooperate to allow the insertion of the ring between the turbine shaft and the degassing tube and the axial stop of the ring against the dog teeth of the turbine shaft.

The invention also relates to a turbomachine comprising such an assembly. The invention finally relates to a method of coupling a turbine shaft to a turbomachine degassing tube, the turbine shaft and the degassing tube being parts of revolution about respective axes, the shaft turbine comprising, on an inner surface, an annular portion comprising a rim, and the tube comprising a circumferential bead, adapted to abut against the rim of the turbine shaft, the method being characterized in that it comprises the steps of: - bringing the degassing tube into the turbine shaft until the bead abuts against the rim of the turbine shaft, - bringing a wedging ring between the degassing tube and the turbine shaft, said ring being slotted or formed of a plurality of ring sectors held together by an annular spring, and - inserting a nut between the degassing tube and the setting ring to deform the ring until it comes in support i against the inner surface of the turbine shaft. Advantageously, but optionally, the method according to the invention further comprises at least one of the following features: the method further comprises the steps of setting an anti-rotation ring to the degassing tube and to the nut, and installing a spiral ring in a housing adapted to the nut to prevent axial movement of the anti-rotation ring. - The ring is formed of a plurality of ring sectors held together by an annular spring, wherein the steps of bringing the ring and insert the nut are simultaneous, the ring being mounted on the nut. - The ring is split, and the turbine shaft comprises, on an inner surface, a circumferential groove defined axially by two flanges, the first flange having a height relative to the inner surface at the bottom of the groove greater than the height of the second flange, and the step of bringing the ring comprises compression retraction of the ring, or engagement of the ring through dog clutch notches of the shaft flange. The setting ring of the assembly proposed by the invention ensures, while being maintained in the circumferential groove of the turbine shaft, an axial stop of the degassing tube with respect to said shaft.

In addition, the ring being held between the shaft and the degassing tube, bearing against the inner surface of the turbine shaft, it prevents relative rotation of the shaft around the tube. Finally, the forces experienced by the ring, in particular during the acceleration and deceleration phases, are distributed over the circumference of the ring, which limits the deformations of the ring. DESCRIPTION OF THE FIGURES Other characteristics, objects and advantages of the present invention will appear better on reading the detailed description which follows, and with reference to the appended drawings given by way of non-limiting examples and in which: FIG. 1 , already described, is an axial sectional view of a coupling system of a turbine shaft to a degassing tube of the prior art, - Figure 2a shows a two-dimensional view in axial section of a assembly comprising a turbine shaft coupled to a degassing tube according to one embodiment of the invention. FIG. 2b represents an axial three-dimensional perspective view of the assembly of FIG. 2a; FIG. 3a shows a partial axial sectional view of an assembly according to another embodiment of the invention; - Figures 3b and 3c respectively show exploded and perspective views of a ring mounted on a nut of the embodiment of Figure 3a. - Figure 4 shows the assembly of a degassing tube in a turbine shaft for stopping in rotation of these elements relative to each other, - Figure 5a shows a wedging ring used in a embodiment of the invention inserted in a turbine shaft, - Figures 5b and 5c show the installation of a setting ring according to another embodiment of the invention in a turbine shaft, - Figure 6a represents a step of inserting a nut on the degassing tube to keep the ring bearing against the turbine shaft; - FIG. 6b shows the installation of an anti-rotation system of a ring and of a nut relative to the degassing tube; - Figure 6c shows the installation of an axial stop system of the ring and the nut once mounted between a degassing shaft and a turbine shaft. FIGS. 7a to 7f and 9 illustrate the main steps of a method of coupling a turbine shaft to a degassing tube according to one embodiment of the invention; FIGS. 8a to 8d and 9 represent the main steps of a method of coupling a turbine shaft to a degassing tube according to another embodiment of the invention. FIG. 10, already described, represents an example of a turbomachine in which the invention can be implemented. DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION With reference to FIG. 10, a turbomachine 1 is shown which comprises one or more compression sections of the air admitted into the engine, and one or more turbine stages enabling relax the combustion gases.

A first expansion is made in a high pressure stage 6 immediately downstream of the combustion chamber and which receives the gases at the highest temperature. The gases are expanded again by being guided through so-called low pressure turbine stages 7, or otherwise called low pressure turbine 7. The low pressure turbine 7 comprises a turbine shaft 10 rotated by the expanded gases, which is integral in rotation and in translation with a degassing tube 20 of the turbomachine by means of coupling elements described hereinafter.

Referring to Figures 2a and 2b and 3a, there is shown an assembly 100 comprising a turbine shaft 10 coupled to a degassing tube 20 in rotation and in translation. The turbine shaft 10 and the degassing tube 20 are two pieces of revolution about respective axes. Once coupled, the degassing tube 20 extends inside the turbine shaft 10 centrally, so that the axes of revolution of the shaft and the tube coincide in the same axis XX, shown in the figures, and corresponding to the axis of rotation of the turbomachine. The turbine shaft 10 comprises an inner surface 11, comprising an annular portion 12 comprising an upstream flange (relative to the air flow) 16 to form an axial abutment of the degassing tube. According to a first embodiment shown in Figures 2a and 2b, the turbine shaft 10 also comprises, on its inner surface 11, downstream of the flange 16, a groove 14 extending axially between two flanges 13, 15 's. each extending radially towards the axis XX.

According to a second embodiment shown in FIG. 3a, the turbine shaft 10 comprises the annular portion 12 comprising an upstream flange 16, said portion also forming an upstream rim 13, but the inner surface of the turbine shaft does not include second flange 15 downstream from the first. All of these portions are advantageously symmetrical about the X-X axis. In particular, the flanges 13, 15 and the groove are very advantageously circumferential. In addition, the heights of the edges h13 and h15, measured relative to the bottom of the groove 14, (that is to say, with respect to the internal surface of the shaft at the groove) are different. In other words, the respective distances d13 and d15 measured in a radial direction with respect to the X-X axis between the X-X axis and the end of each rim are different. Preferably, the height h13 of the first flange 13 with respect to the bottom of the groove 14 is greater than the height h15 of the second flange 15 with respect to the bottom of the groove, or in other words the distance d13 between the first flange 13 and the X-X axis is smaller than the distance d15 between the second flange 15 and the axis. The degassing tube 20 comprises an outer surface 21 comprising successively, in the axial direction and upstream downstream relative to the air flow: a bead 22 circumferential, adapted to abut against the flange 16 of the shaft of turbine, the bead 22 being provided at its downstream end with a protruding circumferential lug 23, and a portion 24 provided with a thread 25. As can be seen in particular in FIG. 4, the bead 22 advantageously comprises flats 26, preferably two in number and arranged diametrically opposite on the bead. These flats make it possible to stop the degassing tube in rotation with respect to the turbine shaft. Advantageously, the turbine shaft then has corresponding flats (not shown) on its portion 12. The degassing tube is then positioned in the turbine shaft so as to bring opposite portions 12 and 22 of the tube and the tree, and if necessary to put the flats in front of them. In this configuration, the bead 22 of the degassing tube advantageously abuts against the upstream flange 16 of the turbine shaft, the degassing tube being inserted into the turbine shaft by translation from the downstream end of the shaft. upstream, and the lug 23 is vis-à-vis the first rim 13.

The degassing tube 20 is thus in axial stop upstream with respect to the turbine shaft. Therefore, in the embodiment of Figures 2a and 2b, the lug 23 must be able to cross the second flange 15 but not the first; which implies that the height h23 of the lug with respect to the axis XX must be greater than the distance d13 which separates the first rim from the axis and is smaller than the distance d15 which separates the second rim 15 from the axis ( thus the lug is not blocked by the rim). The assembly 100 further comprises a wedging ring 30, visible in Figures 3b and 3c for the second embodiment and 5a and 5b for the first embodiment. This ring is disposed between the turbine shaft 10 and the degassing tube 20, and held in abutment against the inner surface 11 of the shaft, clamped between the shaft and the tube, and resting against the bead 22 (and in particular the lug 23) of the degassing tube, allowing locking in rotation and in translation of the tube relative to the shaft, the locking in rotation being also improved by the engagement of the shaft and the tube at the bead 22 provided with flats. DESCRIPTION OF THE PREFERRED EMBODIMENT According to the first embodiment, which is the one shown specifically in FIGS. 2a, 2b, and 5a to 7f, in which the inner surface of the turbine shaft has a circumferential groove 14 delimited by the two flanges 13, 15, the ring 30 is received in said groove between the two flanges. In this case, the locking in translation ensured by the tightening of the ring is also improved by the second flange 15.

Very advantageously, as represented in FIG. 5a, the wedging ring 30 is a retractable split ring enabling it, on the one hand, to be retracted before its installation to enable it to cross the rim 15 and to be at the right of the groove 14 and also allowing it to be expandable to come, once crossed the flange 15, bearing against the inner surface 11 of the shaft.

According to an alternative embodiment shown in FIGS. 5b and 5c, the wedge ring is always split, and has on its external surface a plurality of clutch teeth 32. The rim 15, instead of being a circumferential rim, presents then a plurality of dog teeth 17 adapted to cooperate with those 32 of the ring.

In this case, instead of retracting the ring to cross the rim 15, it is inserted directly between the turbine shaft and the degassing tube so that it comes to lie at the right throat 14. The teeth of claws of the ring are then offset relative to those of the rim 15. Then the ring is rotated as shown in Figure 5c, so that the dog teeth 32 are opposite those of the flange 15, and thus the rim blocks any translation downstream of the ring. Then, the ring being split, it can then be extended so that it bears against the inner surface 11 of the shaft.

To do this, the assembly further comprises a nut 40, which is screwed onto the threaded portion 24 of the degassing tube 20, and is thus interposed between the degassing tube 20 and the setting ring 30, as visible on the Figure 7a. The progressive screwing of the nut on the degassing tube 20 progressively deforms the ring by expansion to tighten it against the turbine shaft. In this respect, the ring advantageously has, as can be seen in FIGS. 7a to 7f, a trapezoidal section defining, on the circumference of the ring, an inner surface 31 in a truncated cone. The nut 40 has an outer surface 41 in the form of a truncated cone, thus creating a cone-cone sliding connection between the nut and the ring 30 which makes it possible, as the nut is screwed on the 25 of the degassing tube 20, and taking into account the axial locking of the ring, to enlarge the diameter of the ring 30 homogeneously on its circumference, then to tighten the ring to the nut once it bearing on the inner surface 11 of the shaft 10.

According to a particular embodiment which is represented in FIG. 5a, to improve the centering of the ring and the locking in rotation of the tube with respect to the turbine shaft, with reference to FIG. 5a, the ring advantageously has a square shape. , whose corners are rounded. This embodiment applies to the case where the ring is not clutched.

More specifically, the inner surface of the ring is circular, allowing it to be mounted on the degassing tube itself of circular section, and the outer surface of the ring defines a square section, the corners are chamfered. The support of the ring 30 on the inner surface 11 of the shaft 10 is then limited to four regularly distributed points on said surface, corresponding to the four corners of the ring 30. The assembly 100 finally comprises an anti-rotation ring. rotation 50 of the ring 30 and the nut 40. As can be seen in FIGS. 5b, 5c and 6a, the degassing tube, the ring 30, and the nut 40 comprise on their circumference a plurality of notches 29, 39, 49, each notch of the tube being aligned with that of the ring and that of the nut when these elements are in position. With reference to FIG. 6b, the anti-rotation ring 50 has the shape of a ring 51 which comprises a plurality of protruding portions 59 on its internal and external surfaces, which engage in the notches 29, 39, 49 to block any relative rotation between the tube, the ring and the nut.

More specifically, the ring is disposed between the tube and the nut, and the protruding portions on the outer surface of the ring are longer than those on the inner surface to be engaged in the notches of the nut and in those of the ring.

Thus the nut 40 is locked in rotation relative to the degassing tube 20. Finally, with reference to FIG. 6c, the assembly 100 comprises an axial locking ring 60 of the spiral ring type which, once engaged in a housing the nut 40 provided for this purpose, at the downstream end of the nut relative to the air flow, prohibits any axial translation of the anti-rotation ring 50.

The assembly thus proposed thus comprises a degassing tube 20 coupled to a turbine shaft 10 in a robust manner in rotation as in translation. Description of the Second Embodiment According to the second embodiment which is specifically shown in FIGS. 3a to 3c and 8a to 8d, in which the internal surface 11 of the turbine shaft does not comprise a flange 15, the locking ring 30 is a ring formed of a plurality of sectors of rings 33 joined together by a circular spring 34 (Figure 3b).

Advantageously, the ring is formed of a number of sectors between 2 and 10, and preferably between 3 and 5, to avoid multiplying the games present in the set. Each ring sector comprises on its external surface a groove 35 able to receive the circular spring 34.

As in the first embodiment, the ring is pressed against the turbine shaft by means of a nut 40, which comprises on a frustoconical outer surface 41, and which is screwed onto the threaded portion of the degassing tube 20 The ring also comprises an inner frustoconical surface 31 which can co-operate by cone-cone sliding with the surface 41 of the nut 40. The fact that the ring is distributed in ring sectors joined by an annular spring also allows to deform to enlarge its diameter and be tight against the turbine shaft.

In addition, the ring and the nut are shaped to be mounted simultaneously between the turbine shaft 10 and the degassing tube. In this regard, the nut comprises, on its outer surface 41, a circumferential housing 42 carrying the frustoconical surface, the housing being delimited axially by an upstream flange 43 and a downstream flange 44. The two collars 43, 44 are circumferential and extend radially outwards with respect to the axis of revolution of the nut in order to be able to contain the setting ring 30. The locking ring 30 has in turn a first portion 36 carrying the frustoconical surface, this portion being suitable to be received in the housing 42 of the nut. In particular, the portion 36 of the ring has an extension, in the axial direction (that is to say in the direction of the axis of revolution of the ring, which coincides with that of the nut when the ring is positioned around the nut), which is less than the extension in that direction of the housing. B is the clearance between the portion 36 of the ring and the flanges 43, 44 of the nut when the ring is positioned around the nut. In addition, the ring 30 has a circumferential protrusion 37, adjacent to the portion 36, on the smaller diameter side of the truncated cone formed by the inner surface of the ring.

This protuberance forms a recessed shoulder to extend beyond the upstream collar of the nut when the first portion 36 of the ring abuts against said flange. To do this, the distance between the axis of revolution of the ring and the inner surface of the protuberance is greater than that between the axis of revolution of the nut and the outer surface of the flange. In addition, the protuberance extends beyond the collar by a greater distance B, the clearance between the housing of the nut and the axial extension of the first portion. In other words, the protuberance has an axial extension, measured between its upstream end and its connection with the first portion 36, greater than the sum of the clearance B and the axial thickness of the collar. This ensures the clamping of the ring bearing against the inner surface 11 of the turbine shaft during assembly. Indeed, during assembly, as shown in Figure 8a, the ring is already mounted on the nut, in a position where the first portion 36 is in abutment against the upstream flange 43 of the nut, and all one of the two is inserted between the degassing tube 20 and the turbine shaft 10. In FIG. 8b, the nut is then screwed onto the thread of the degassing tube, and thus brings the protuberance 37 closer to the pin 23 of the nozzle. 22 bead of the degassing tube, until the protrusion 37 abuts against the lug. Continuing the screwing of the nut, the bringing of the nut towards the bead 22 causes a deformation of the ring by cone-cone sliding, until it is pressed against the inner surface of the turbine shaft. in Figure 8c. At this stage, the flange 43 must have a minimum positive clearance with the lug 23, and there must also remain a strictly positive clearance B between the downstream flange 44 and the downstream face of the ring 30, to ensure the clamping of the flange. ring against the turbine shaft. The fact that the clearance between the portion 36 of the ring and the housing 42 of the nut is greater than the projection of the protuberance relative to the flange 43 ensures that the clamping level of the ring against the turbine shaft is reached before the ring is in abutment against the downstream flange. Figure 8d shows a schematic sectional view of the ring on the nut after clamping. The sectors of rings 33 are spaced from each other to allow the enlargement of the diameter of the ring, and so they are in abutment against the shaft. To maintain the tightening, the assembly further comprises an antirotation ring (not shown) of the nut 40, as in the previous embodiment.

Unlike the first embodiment, the conformation of the ring and the nut allows that the locking in rotation of the nut also locks the ring. Thus, if the degassing tube and the nut comprise notches aligned to receive protruding portions of the anti-rotation ring, the setting ring 30 is devoid of it. In this way, the protruding portions of the outer surface of the ring do not need to be extended relative to those on the inner surface. The assembly also comprises an axial stop ring (not shown) of the spiral ring type which, once engaged in a housing of the nut 40 provided for this purpose, at the downstream end of the nut by relative to the flow of air, prohibits any axial translation of the anti-rotation ring 50.

We will now summarize, with reference to Figure 9, the mounting method of the previously described assembly.

The method comprises a first step 1100 of positioning the degassing tube in the turbine shaft, engaging the flats of the tube and of the opposite shaft if appropriate, the bead 22 being in abutment with the rim 16 'of so that the tube is in axial abutment against the shaft, and the circumferential pin 23 of the tube being vis-à-vis the first rim 13 of the shaft. This step, represented in FIG. 7a which relates specifically to the first embodiment, is nonetheless applicable to both embodiments. The method then comprises a step 1200 during which a setting ring 30 is brought between the turbine shaft 10 and the degassing tube 20, and a step 1300 for inserting and screwing a nut 40 on the threading. 25 of the degassing tube 20 for deforming the clamping ring 30 to be clamped against the turbine shaft 10. For the first embodiment, the step 1200 is shown in Figure 7b. In this case, the ring 30 brought between the shaft and the tube is split. Two variants are possible.

According to a first variant 1210, represented for example in FIGS. 5a, 7b and 7c, the ring is retracted by compression so as to be able to pass it between the degassing tube 20 and the second flange 15 of the shaft, until it comes into abutment against the circumferential lug 23 of the tube, the ring then being located axially between the lug and the second flange 15, at the right of the circumferential groove 14 of the shaft. The split ring 30 then resumes its initial shape by elasticity. It is then disposed in the circumferential groove 14. In a variant 1220, as in FIGS. 5b and 5c, a ring is engaged in position by passing it through the notches of clutch of the turbine shaft, then it is pivoted around its axis to bring the clutch teeth of the ring facing the clutch teeth of the turbine shaft. Advantageously, in both cases there then remains a radial clearance between the inner surface 11 of the shaft and the ring 30. The step 1300 is performed after step 1200.

Referring to Figure 7d, the method then comprises a step 1300 for screwing a nut 40 onto the thread 25 of the degassing tube 20. During this step, the nut is interposed between the wall of the tube 20 and the wedging ring 30. Due to the cone-cone sliding connection between the ring and the nut, and that the ring is stopped in translation between the two flanges 13, 15 of the shaft, the screwing of the nut causes the progressive widening of the section of the ring 30, then its support against the inner surface 11 of the shaft and its tightening to the nut, for securing in rotation the ring, the shaft and the nut. According to the second embodiment, the steps 1200 of insertion of the ring and 1300 of insertion and screwing of the nut are simultaneous. These steps are shown in Figures 8a to 8c and performed in accordance with the corresponding description. Once the nut is completely screwed in, 1400 is positioned an antirotation ring 50 between the nut 40 and the degassing tube 20, so that the notches of the nut 40 and the tube 20 receive the complementary protuberances the anti-rotation ring. rotation 50, and that the nut 40 is locked in rotation relative to the tube 20. This step is shown in Figure 7e for the first embodiment but is similar for both modes. In the first mode however, the setting ring 30 also has notches which receive the protuberances of the ring 50. Finally, a spiral ring 60 is then mounted 1500 on the nut to axially fix the anti-rotation ring 50 on the ring. 'nut. This step is shown in Figure 7f for the first embodiment but its implementation is similar for both modes.

The assembly of the assembly 100 is therefore simple and fast implementation. In addition, the second embodiment has an additional advantage of speed because the steps 1200 and 1300 are implemented simultaneously. It thus saves a step of assembly.

Claims (15)

REVENDICATIONS1. Assembly comprising: - a turbine shaft (10), of revolution about an axis (XX), comprising, on an inner surface (11), an annular portion (12) comprising a rim (16), - a tube of degassing (20) revolution adapted to extend inside the turbine shaft (10), the tube (20) comprising a bead (22) circumferential, adapted to abut against the flange (16) of the turbine shaft (10), characterized in that it further comprises a wedging ring (30), disposed between the degassing tube (20) and the turbine shaft (10), said ring being maintained in bearing against the internal surface (11) of the turbine shaft and against the bead (22) of the degassing tube (20) to ensure the coupling in rotation and in translation of the turbine shaft (10) with the tube degassing (20). 2. The assembly of claim 1, wherein the bead (22) of the degassing tube comprises flats (26) adapted to stop a relative rotation between the tube (20) and the turbine shaft (10). 3. An assembly according to one of claims 1 or 2, further comprising a nut (40) mounted on the degassing tube (20), and now bearing the ring (30) against the turbine shaft. 4. The assembly of claim 3, wherein the ring (30) and the nut (40) have, respectively, one an inner surface (31) and the other an outer surface (41) truncated cone, allowing a cone-cone sliding clamping of the ring on the nut. 5. An assembly according to one of the preceding claims, wherein the wedge ring comprises a plurality of ring sectors (33). An assembly according to claim 5, wherein each ring sector (33) comprises, on a radially outer surface, a groove (35), and the offset ring further comprises a circular spring (34) adapted to be received in the groove of the ring sectors (33). 7. Assembly according to one of claims 5 or 6, wherein the nut (40) comprises, on its outer surface (41), a housing (42) circumferential axially delimited by an upstream collar (43) and a downstream flange (44), and the ring has a first portion (36) adapted to be received in the housing (42) and, adjacent to said portion, a circumferential protuberance (37) forming a shoulder such that the first portion (36) can come in abutment against the upstream flange (43) of the nut and the protuberance (37) extends upstream beyond said flange, the ring and the nut being such that: the first portion (36) of the ring has, in an axial direction, an extension less than the extension of the housing in said direction, and - when the ring (30) is received in the housing (42), abutting against the upstream collar (43) of the nut, the upstream end of the protuberance (37) is offset axially relative to the upstream flange (43) of the nut, a distance greater than the difference in axial extension between the housing and the first portion of the ring. 8. Assembly according to one of claims 1 to 4, wherein the turbine shaft (10) comprises, on an inner surface (11), a circumferential groove (14) defined axially by two flanges (13, 15), and the degassing tube (20) further comprises a circumferential pin (23) abutting against a first flange (13) of the turbine shaft (10), and the setting ring (30) is a split ring received in the circumferential groove (14) between the lug and the second flange (15). 9. An assembly according to claim 8, wherein the wedge ring (30) is a ring having an outer surface of square section whose corners are chamfered. 10. The assembly of claim 8, wherein the ring (30) and the turbine shaft (10) comprise dog teeth adapted to cooperate to allow the insertion of the ring between the turbine shaft (10) and the degassing tube (20) and the axial stop of the ring (30) against the clutch teeth of the turbine shaft (10). 11. Turbomachine (1), comprising an assembly according to one of the preceding claims. 12. A method of coupling a turbine shaft (10) to a turbomachine degassing tube (20), the turbine shaft and the degassing tube being parts of revolution about respective axes, the shaft turbine engine (10) comprising, on an inner surface (11), an annular portion (12) comprising a rim (16), and the tube (20) comprising a circumferential bead (22) adapted to abut against the rim (16) of the turbine shaft (10), the method being characterized in that it comprises the steps of: - bringing (1100) the degassing tube into the turbine shaft (10) until the bead (22) comes into abutment against the rim (16) of the turbine shaft, - bring (1200) a setting ring (30) between the degassing tube and the turbine shaft, said ring being split or formed of a plurality of ring sectors held together by an annular spring, and - inserting (1300) a nut (40) between the degassing tube (20) and the bag a wedge (30) for deforming the ring (30) until it bears against the internal surface (11) of the turbine shaft. 13. A coupling method according to the preceding claim, further comprising the steps of securing (1400) an anti-rotation ring (50) to the degassing tube and the nut, and installing (1500) a spiral ring. (60) in a housing adapted to the nut (40) to prevent axial displacement of the anti-rotation ring. The method of coupling according to one of claims 12 or 13, wherein the ring is formed of a plurality of ring sectors (33) held together by an annular spring (34), wherein the steps of bringing the ring (1200) and inserting (1300) the nut are simultaneous, the ring being mounted on the nut. 15. Coupling method according to one of claims 12 or 13, wherein the ring is slotted, and the turbine shaft (10) comprises, on an inner surface (11), a circumferential groove (14) defined axially. by two flanges (13, 15), the first flange (13) having a height with respect to the inner surface (11) at the bottom of the groove (14) greater than the height of the second flange (15), and step of bringing the ring comprises the retraction by compression of the ring, or a commitment of the ring through dog notches of the rim (15) of the shaft.