FR3009739A1 - IMPROVEMENT FOR LOCKING AUBAGE SUPPORT PARTS - Google Patents

Abstract

The invention relates to an assembly comprising: - two pieces (10, 20) of revolution, disposed one inside the other concentrically about a turbomachine axis, and a split ring for holding parts , comprising a U-shaped cross-section adapted to receive one end of the two parts, characterized in that it comprises a system (50) for stopping the rotation of the crown, comprising: a hook (51), arranged at the level of the slot of the ring gear and adapted to receive the ends of the pieces, the hook (51) comprising an arm (52), provided with a through-hole forming a housing, extending along a piece (20), and - A fixing piece (59) of the hook, passing through the part (20) along which extends the arm (52), and being received in the housing of the hook. The invention also relates to a turbomachine comprising such an assembly and a method of assembling this assembly.

Description

FIELD OF THE INVENTION The invention relates to an assembly for locking in relative translation two turbomachine blade support parts such as for example a fixed blade platform and a vane support ring or a ring. movable blade and a ring casing. The invention is particularly applicable to the locking of a turbomachine flow distribution vane platform to a support ring of said vane distribution.

STATE OF THE ART An example of a turbomachine has been illustrated in FIG. 5. A turbine engine 1 typically comprises a nacelle which forms an opening for the admission of a given 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, high pressure 6 or low pressure 7, conventionally comprises one or more stages, each consisting of a row of turbine blades. Fixed turbine, also called distributor, followed by a row of turbine blades, which form the rotor. The dispensers are fixed together via a ring. Dispenser 2 deflects the gas stream drawn at the combustion chamber to the turbine blades at a suitable angle and speed to drive these rotating blades and the rotor of the turbine in rotation.

Each distributor is sectorized, that is to say formed of several distributor sectors arranged circumferentially end to end around a longitudinal axis X-X of the turbomachine. Each distributor sector comprises a plurality of blades extending radially relative to the axis XX of the turbomachine so as to connect a radially inner annular element (or inner platform) and a radially outer annular element (or outer platform), which together form an annular vein opposite the moving blades of the turbine. On the external platform of the distributor is mounted a support ring of the distributor, which is a part of revolution around the axis of the turbomachine.

The ring and the distributor must be integral with each other. In this respect, means for blocking a relative translation in the axial or radial direction (relative to the axis of the turbomachine) must be provided. Document FR 2 887 920 discloses locks applied in a similar manner to a turbomachine casing section extending around a mobile blade ring. The locks are in the form of ring sectors having a U-shaped cross-section to be able to receive a downstream end of the ring and a distributor sector, each lock being tightly mounted on the ring and the casing to hold them firmly together. one of the other.

This solution is nevertheless not transferable to the locking of a distributor platform (that is to say fixed blade) to a support ring of this distributor because of the mechanical and thermal stresses too important in these parts, resulting respectively from the forces of the air flow on the distributor and the thermal expansion of the parts.

Indeed, in case of tightening a lock on the parts, the absence of clearance between the lock on the one hand and the distributor and the ring on the other hand, implies that the stresses in the parts are translated into significant forces applied to the lock, causing deformation and rapid degradation thereof. There is therefore a need for an increased life system, making it possible to block a distributor ring with an external distributor platform. PRESENTATION OF THE INVENTION The object of the invention is to overcome the problem mentioned above. In particular, an object of the invention is to provide an assembly for keeping together two pieces of turbomachine vane support reliably while having a long service life. Another object of the invention is to provide an assembly that is easy to assemble.

In this regard, the subject of the invention is an assembly comprising: two turbomachine blade support parts, the parts being of revolution, disposed one inside the other concentrically around a turbomachine axis, and - a holding ring parts, the ring being split and comprising a U-shaped cross section adapted to receive one end of the two parts, the assembly being characterized in that it comprises a stop system in rotation of the split crown, comprising: - a hook disposed at the slot of the ring and adapted to receive the end of the two pieces, the hook comprising an arm extending along one of the pieces, said arm being provided with a through hole forming a housing, and - a fixing pin of the hook, the peg passing through the workpiece along which extends the arm of the hook and being received in the housing of the hook. Advantageously, but optionally, the invention furthermore comprises at least one of the following features: the inner part is a fixed blade platform or an annular blade, and the outer part is respectively a support ring; fixed blade or a ring housing, - The hook further comprises a through groove adjacent the housing and opening on one side of the hook to allow the insertion of the pin in the housing by the groove. - The groove has converging edges towards the housing to prevent the exit of the pin once inserted into the housing. - The hook further comprises a cavity adjacent to the housing for elastic deformation of the hook on either side of the housing during the insertion of the pin. - The cavity has a width less than the width of the pin. - The hook arm extends along the outer part and the pin passes through said part. - The crown holding parts is engaged by interconnection with one of the parts.

The invention also relates to a turbomachine, comprising at least one such assembly. The invention also relates to a method of assembling such an assembly, comprising the steps of: - mounting the two parts of revolution one inside the other concentrically, - engage the split ring with the pieces so that the crown receives the end of said pieces, - engage a fixing pin through one of the pieces, and - bring a hook at the slot of the crown so that he receives the end of the pieces, and position the piece in the hook's housing.

Advantageously, but optionally, during the assembly process, the step of bringing the hook and positioning the pin in the housing comprises positioning the hook against the end of the pieces so that the pin is next to the groove, and the movement of the hook to the parts so as to successively engage the pin in the groove and in the housing.

DESCRIPTION OF THE FIGURES Other characteristics, objects and advantages of the present invention will appear better on reading the detailed description which follows, with reference to the accompanying drawings given by way of non-limiting example and in which: FIGS. 1a show a cross-sectional view of an assembly according to three embodiments of the invention; FIGS. 2a and 2b show elements of an assembly according to the embodiment of FIG. 1a; FIGS. 3a, 3b , 3c are views from different perspectives of an assembly according to Figure Ia, - Figure 3d represents a stop hook in rotation. - Figure 4 schematically shows the main steps of the assembly method of an assembly according to the invention. - Figure 5, already described, is a sectional view of an example of a turbomachine on which the assembly according to the invention can be implemented.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT OF THE INVENTION With reference to FIG. 3a, there is shown an assembly 100 which comprises two support pieces of a turbomachine blade, the two parts being of revolution, and disposed one inside the other concentrically about the axis XX of the turbomachine, visible in Figure 5. For a support part of a turbomachine blade is understood: - in the case of a fixed blade, for example a flow distribution vane: an external vane platform interconnecting the blades of the vane, or a support ring of a vane, which is arranged around said platform, or a blade ring housing disposed around said ring. - in the case of a mobile blade; for example a compressor vane, a ring surrounding the vane, or a ring housing, which is disposed around said ring.

The assembly 100 thus comprises two blade support pieces, a radially inner piece 10 and a radially outer piece 20 disposed around the first. According to a preferred embodiment, the inner part 10 is a turbine engine fixed blade platform as a flow distribution vane (also called distributor), the outer part 20 then being a fixed vane support ring. According to an alternative embodiment, the inner part 10 is a mobile blade ring, and the outer part 20 is then a ring housing. According to another variant, the inner part 10 is a fixed vane support ring and the outer part 20 is a ring casing. In Figure 1a, there is shown the assembly 100 in the first case. The inner part 10 is a blade platform which has been shown to have a blade A. The platform 10 comprises an upstream spoiler 11 and a downstream spoiler 12 with respect to the air flow, represented in the figure by an arrow F. The spoilers upstream 11 and downstream 12 respectively form the upstream and downstream ends of the platform. The support ring 20 of the vane comprises, at its upstream end, a U-shaped hook 21 adapted to receive the upstream spoiler 11 of the platform, and at its downstream end a flange 22 extending towards the axis and to retain the spoiler downstream of the platform axially downstream. The flange 22 is provided with a notch 23 adapted to be able to pivot the corner of the downstream spoiler 12 in this notch during the positioning of the ring 20 on the platform. The ring support and pivots around the platform (the pivot being at the spoiler downstream), and receives at the hook 21 upstream spoiler. This results in an axial clearance between the hook 21 and the upstream spoiler 11 once the ring is in position on the platform 10. In addition, as shown in the figure, at the edge 22 the downstream spoiler 11 is not retained radially.

In the case where the inner part 10 is a mobile blade ring, and the outer part 20 is a ring housing, with reference to Figure 1b, the ring housing 20 has downstream circumferential flanges 22 which are positioned opposite downstream circumferential flanges 12 of the blading ring 10.

A protuberance 13 on said flange makes it possible to prevent displacement of the casing upstream with respect to the blading ring 10. However, in the opposite direction downstream, and in the radial direction, the relative movements of the casing 20 and the blading ring 10 are not blocked.

The assembly 100 thus comprises a locking system 30 parts to prohibit their relative axial and radial translation (relative to the axis of the turbomachine). As can be seen more particularly in FIGS. 3a to 3d, this system 30 comprises a ring 40 having a U-shaped section comprising two parallel arms 41, 42 interconnected at one end by a transverse bar 43. The length of the transverse bar 43 defines the spacing between the arms, which must be sufficient to receive one end of the two parts 10, 20. In the case where the parts are respectively a blade platform and a support ring, the crown receives the downstream spoiler 12 of the platform and the rim 22 of the ring, so that an inner arm 41 of the crown is facing an inner face of the downstream spoiler 12 and an outer arm 42 is opposite the outer face of the ring. In the case of a vane ring 10 surrounded by a ring casing 20, the crown receives the circumferential downstream flanges 12, 22 of the two parts, the inner arm 41 being opposite the inner face of the downstream flange 12 of the ring, and the outer arm 42 facing the outer face of the downstream flange 22 of the housing. The ring 40 can be tightly mounted on the parts 10, 20, so as to prohibit their relative translation in the axial and radial directions, or alternatively, and preferably mounted by interconnection, with play on the parts. This case is described in more detail below. In addition, the ring is split, in particular to allow deformations of the parts 10, 20, for example in case of thermal expansion.

The locking system 30 then also comprises a rotational locking member 50 of the ring 40 with respect to the two parts 10, 20. This rotational stop member is advantageously positioned at the slot 45 of the ring 40. As illustrated in FIGS. 1a, 1b, and 3a to 3d, the rotational stop member 50 comprises a hook 51 which is adapted to receive the end of the two pieces 10, 20. In the case where the pieces are a flat fixed blade form 10 and a support ring 20, the ends are as before the end of the downstream spoiler 12 and the flange 22. In the case where the parts are a movable blade ring 10 and a crankcase ring, the ends are their circumferential downstream flanges 12, 22. The hook 51 comprises in particular an arm 52 extending along one of the parts 10, 20, advantageously along the outer part 20. The arm 52 comprises a through hole 53 forming a housing for a peg 59 extending through an orifice (not shown) provided in the part along which the arm extends. The orifice 53 advantageously has the same shape as the section of the pin 59, namely advantageously a circular shape.

The hook 51 is mounted at the slot 45 of the crown to receive the parts, and the pin 59 is inserted into the housing 53 of the hook, thus maintaining the angular position of the hook of the ring 40 constant. As seen more specifically in Figure 3a, the hook 51 further comprises a groove 54 therethrough adjacent the housing 53, and opening on one side of the hook. In this way, the pin can be inserted into the housing by sliding in the groove until it reaches the housing 53. The groove preferably has edges converging towards the housing, the housing itself having a diameter greater than spacing the edges of the groove at its end adjacent to the housing, so that the pin, once inserted into the housing by movement in the groove, can not come out. This requires slightly deforming the hook, at the edges of the groove 54, at the time of passage of the pin 59 to allow its passage. The hook 51 then advantageously comprises a cavity 55, preferably through, and adjacent to the housing, this cavity 55 being preferably opposite the groove with respect to the housing, thus allowing the hook 51 to deform elastically when the insertion of the pin 59 in the housing 53. This cavity 55 advantageously has a width less than the diameter of the housing 53, to prevent a movement of the pin from the housing 53 to the cavity 55 once inserted into the housing 53. A preferred application of the rotational stop member 50 of the ring gear 40, shown in particular in FIGS. 2a, 2b, and 3a to 3c, relates to the use of such a member to stop in rotation a ring 40 mounted by interconnection on the parts. 10, 20. The assembly by clutching the crown 40 on the parts 10, 20 is advantageous because it allows to stop in translation in the radial direction of the two parts 10, 20 one p relative to the other (because the inner part 10 is held by the ring against the outer part), and in axial relative translation, because the dog teeth 44 and the transverse bar 43 of the crown deprive the outer piece 20 of movement axial. In addition, the assembly by interconnection of the crown on the parts allows to allow the presence of clearances between the ring and the parts 10,20, which allow the parts to expand, especially because of the thermal stresses involved, without reducing on their life span. In addition, the absence of clamping implies that the crown must not withstand significant mechanical stresses. This makes it possible to reduce the dimensioning of the ring gear, and therefore to reduce the bulk and the weight of the ring gear, which reduces the weight of the entire turbine engine in which the parts 10, 20 are installed. In the case of assembly by interconnection, the ring 40 and one of the parts, preferably the outer part 20, are shaped so as to cooperate together by interconnection. In this regard, they comprise dog teeth 44, 24, complementary, that is to say that the dog teeth of each piece are of equal length and distributed at constant angular interval, and the angular interval between two teeth dog 24, 44 of a piece corresponding to or greater than the length of a dog tooth 44, 24 of the other piece.

According to a preferred embodiment, which is illustrated in Figures 2b and 3a, the dog teeth 44 are protuberances of the outer arm 42 of the crown, which project inwards, that is to say towards the axis of revolution of the crown. On the other hand, the outer piece 20 comprises on its outer surface the dog teeth 24, extending radially in the opposite direction of the axis of revolution of the part, as shown in Figure la. According to an alternative embodiment shown in Figure 1c, it is the inner part which includes clutch teeth 24, positioned on its radially inner surface and extending radially. The ring 40 then includes dog teeth 44 on its inner arm 41, the teeth then protruding outwardly. The crown can thus be mounted by inserting the dog teeth 44 of the crown opposite the intervals between two claw teeth 24 of the part 20, then pivoting the ring relative to the workpiece so that the dog teeth 44 are in position. look of teeth 24.

In this case, the rotational arresting member 50 makes it possible in particular to prevent the crown from pivoting relative to the workpiece 20 until the dog teeth 24 and 44 are offset and that the crown can thus be disengage.

We will now describe, with reference to Figure 4, the main steps of a mounting method 1000 of the assembly 100 previously described. In a first step 1100, the two blade support pieces 10 are positioned concentrically one inside the other. The parts are nested together in a manner known to those skilled in the art, to obtain the provisions respectively illustrated in Figure la in one case and 1b in the other case. Then mounted 1200 a crown 40 on the parts. To do this, it is possible to mount the crown 40 by tightening.

Alternatively, if the ring 40 can be mounted by interconnection on the parts, 1220 is positioned a ring 40 by shifting the dog teeth 44 of the ring relative to the dog teeth 24 of one of the parts, and engaging the ring 40 to the pieces so that the ends of the pieces are received between the arms 41, 42 of the ring.

The crown 40 is then rotated 1225 with respect to the parts 10, 20 so that the dog teeth 44 of the ring face the dog teeth 24 of the part, for example the outer part 20, and that thus the crown forms a stop in axial translation of the workpiece. Finally, during a step 1300, is positioned a member 50 for stopping rotation of the ring relative to the parts. To do this, it is best equipped with a hook 51 comprising a groove 54 adjacent to the housing 53. 1310 is engaged an anti-rotation pin 59 through one of the parts, and 1320 is brought to the hook 51 at of the slot, so that it receives the ends of the pieces (in this case the downstream end relative to the air flow, in the axial direction) and that the pin 59 is received in the groove. The hook 51 is progressively displaced so that the peg 59 moves in the groove until it reaches the housing 53. The peg 59 is advantageously locked in the housing by the converging edges of the groove.

An assembly has thus been proposed for locking in axial and radial translation two turbomachine blade support pieces, which has a long service life and is simple to mount.

Claims (11)

REVENDICATIONS1. Assembly (100) comprising: - two pieces (10, 20) of turbomachine blade support, the parts being of revolution, disposed one inside the other concentrically about an axis (XX ) of a turbomachine, and - a ring (40) for holding parts, the ring being split and comprising a U-shaped cross section adapted to receive one end of the two parts, the assembly being characterized in that it comprises a system ( 50) for stopping the rotation of the split ring gear (40), comprising: - a hook (51) arranged at the slot (45) of the ring gear (40) and adapted to receive the end of the two pieces ( 10, 20), the hook (51) comprising an arm (52) extending along one of the pieces (20), said arm (52) being provided with a through hole (53) forming a housing, and - a pin (59) for fixing the hook, the peg passing through the piece (20) along which the arm (52) of the hook (51) extends and being received in the ogement (53) of the hook. An assembly (100) according to claim 1, wherein the inner part (10) is a fixed blade platform or a vane ring, and the outer piece (20) is a support ring respectively. fixed blade or ring housing, 3. Assembly (100) according to one of claims 1 or 2, wherein the hook (51) further comprises a through groove (54) adjacent the housing (53) and opening on one side of the hook to allow insertion the pin (59) in the housing (53) through the groove (54). 4. Assembly (100) according to claim 3, wherein the groove (54) has convergent edges towards the housing (53) to prevent the exit of the pin (59) once inserted into the housing (53). 5. The assembly (100) according to one of claims 1 to 4, wherein the hook (51) further comprises a cavity (55) adjacent to the housing (53) forelastic deformation of the hook (51) of part and of another housing (53) when inserting the pin (59). 6. Assembly (100) according to the preceding claim, wherein the cavity (55) has a width less than the width of the pin (59). 7. Assembly (100) according to one of the preceding claims, wherein the arm (52) of the hook (51) extends along the outer piece (20) and the pin (59) through said piece (20). . 8. Assembly (100) according to one of the preceding claims, wherein the ring (40) for holding parts is engaged by interconnection with one of the parts (20). 9. Turbomachine (1), comprising at least one assembly (100) according to one of the preceding claims. 10. A method of assembling an assembly (100) according to one of claims 1 to 8, comprising the steps of: - mounting the two parts (10, 20) of revolution one inside the l concentrically, engage the split ring (40) with the pieces (10, 20) so that the ring (40) receives the end of said pieces (10, 20), - engage a pin (59) of fastening through one of the pieces (20), and - bringing a hook (51) at the slot (45) of the ring (40) so that it receives the end of the pieces (10). , 20), and position the pin (59) in the housing (53) of the hook (51). 11. A method of assembly according to the preceding claim, applied to an assembly (100) according to one of claims 3 to 6, wherein the step of bringing the hook (51) and to position the pin (59) in the housing (53) comprises positioning the hook (51) against the end of the pieces (10, 20) so that the pin (59) is opposite the groove (54), and the movement of the hook (51) to the pieces (10, 20) so as to successively engage the pin (59) in the groove (54) and in the housing (53).