FR3049645B1 - ROTARY ASSEMBLY FOR TURBOMACHINE WITH ROUND JUNCTION IN U - Google Patents

Abstract

A rotary assembly is concerned comprising a disk (300) of a turbomachine rotor having at least one annular groove (151), a downstream flange (910), a downstream ring (111) mounted in said annular groove, ensuring, for the flange downstream a radial stop and an axial stop. The annular groove (151) is open radially inward and extended downstream by a shoulder (35) extending radially inward, and the downstream ring has an annular groove (37) open radially inwardly. external, so that, for the downstream flange, the radial stop is ensured by engagement of the downstream flange with the shoulder (35) and the axial stop is ensured by engagement of the downstream ring (111) with said shoulder, in the annular groove (151).

Description

ROTARY ASSEMBLY FOR TURBOMACHINE WITH ROUND JUNCTION IN U

The present invention relates to a rotary assembly for a turbomachine fed with air, such as a turbojet engine.

In known manner, such an assembly comprises a rotor disk of the turbomachine mounted rotating about an axis of rotation.

In the rest of the text, it will be understood that the terms "upstream" and "downstream" are defined with respect to the direction of flow or circulation of a fluid, such as air, through the turbomachine, the upstream defining where the fluid arrives on an organ, such as a blade, the downstream where the fluid exceeds the organ. At the inlet, that is to say upstream of the air circuit in the turbomachine, air is sucked, by a blower if necessary, then, while traveling downstream parallel to the axis of rotation, compressed via one or more compressor stages. Kerosene is then injected and mixed with air at a combustion chamber and then ignited, which allows the gases to expand greatly. The latter then escape from the turbomachine by a nozzle that accelerates the speed of the air. The air passes beforehand by one or more turbine stages for driving the compressor part and essential accessories for the operation of the turbomachine, using at least one rotary shaft.

It is common for compressors and / or turbines to include high pressure (HP) and low pressure (LP) stages.

Any compressor and turbine stage includes blades that act on the circulating air.

Thus, a rotor disk has an upstream face through which the air arrives on the blades and an opposite downstream face and radial retaining cells of vanes. Typically, a radially outer periphery of the disk is provided with ribs delimiting axial mounting cells and radial retaining feet of the blades,

An annular downstream flange is disposed axially downstream of the blades with respect to the direction of air flow in the turbomachine, in particular to provide a sealing function between the blade platforms and the disk. An annular downstream rod can then be placed axially downstream of the blades and mounted in an annular groove of the disc, to stop the downstream flange radially and axially.

However, such rotor discs of the state of the art, including that of a turbine HP turbo jet engine of the state of the art, require multiple machining operations and manufacturing tolerances are tight.

Research has therefore been done to study the holding zone of the downstream flange when the part out of its manufacturing tolerances. It has been sought to simplify the geometry of this holding zone to make machining easier, reduce the cost of parts and machining conditions.

A solution reaching at least partly for these purposes is proposed here which provides: - that the annular groove, located in the downstream face of the rotor disk, is open radially inwards (and therefore towards the axis of rotation of the rotor disk). rotor) and extended downstream by a shoulder extending radially inwards, - that the downstream rod has an annular groove open radially outward and axially limited, on either side, by upstream edges. and downstream, so that, for the downstream flange: - said radial stop is ensured by engagement of the downstream flange with the shoulder which extends the annular groove, and said axial stop is ensured by engagement of the downstream rod with said shoulder , in the annular groove.

It will be understood that what is radially outside is further from the axis of rotation of the rotor disk than what radially inside. At this stage, it is specified that "axial" has for direction: oriented along said axis of rotation of the rotor disk of the turbomachine, or parallel to it, while "radial" corresponds to a radial orientation to this axis.

Given the aforementioned main functions of the rotor disk zone designed to hold or retain the downstream flange, one trick here has been to simplify this area of the disk by giving it (preferably only) two contact interfaces to achieve the two stops targeted: axial and radial, and arrange by changing the geometry of the parts vis-à-vis (ring and flange downstream) to adapt to this new geometry of the disk, hence the presence of the arrested snap ring.

In this context, it is also in particular recommended: - that the annular groove of the downstream rod receives a radially inner end of the downstream flange, - that the upstream edge of the downstream rod is engaged radially in the annular groove and axially with the shoulder extending this annular groove, - that the downstream edge of the downstream rod is axially engaged with a face of said radially inner end of the downstream flange, and / or that the shoulder extending the annular groove has two, and preferably only two, contact interfaces for retaining the downstream flange, respectively axially with the upstream edge of the downstream rod and radially with a flange oriented axially upstream of the radially inner end of said downstream flange.

A preferred application is to be found in the case where the rotor disk of the turbomachine is a high pressure turbine disk. Indeed, this area of the turbomachine is an area where the sealing and machining issues, because of the constraints involved, are particularly critical. Simplifying the forms and conditions of assembly is especially important.

In this regard, provide that the annular groove of the downstream rod has a U-shape in this direction.

The proposed solution will require the modification of two parts compared for example to the solution of the HP turbine in the state of the art, namely: - a downstream rod which will change from an O geometry to a geometry U-shaped to ensure two axial supports, - an HP disc whose groove said upper will have been modified to allow axial support, and without lower groove, while such a groove was previously provided.

In particular, two alternatives can be envisaged, which always ensure that the downstream rod can present a bead (L) engaged substantially axially in a substantially axial annular slot of said annular groove. Such a bead on the snap ring and a groove in the rotor disc will maintain the ring in the event that any force pushes it radially inward.

Then, in a lightened solution, it can be provided that the aforementioned flange oriented axially upstream of the radially inner end of the downstream flange is extended radially inwardly by a radial shoulder engaged: in the annular groove of the rod downstream, and axially with the downstream edge of the downstream rod.

In addition to the rotary assembly for a turbomachine that has just been presented is also concerned here such a turbomachine itself, such as a turbojet engine or a turboprop aircraft, which will include this set.

Are also concerned: - a turbomachine rotor rotor supplied with air, usable on the aforementioned rotary assembly, the disc, which is rotatably mounted about its axis of rotation, having: - radial retaining cells of vanes, - an upstream face and an opposite downstream face on the side of which the disk has an annular groove for receiving an annular downstream rod for stopping a downstream flange, the annular groove being open radially inwards and extended towards the downstream by a support shoulder of the downstream rod, the shoulder extending radially inwards; and / or a downstream annular rod, also usable on the aforementioned rotary assembly, this ring thus having a U-shaped annular groove, for receiving a radially inner end of a said downstream flange of a turbomachine rotor disk .

If necessary, the invention will be better understood and other characteristics, details and advantages thereof will become apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings, in which: which: - Figures 1,2,3 schematically in median longitudinal section three areas (three different scales) of a turbomachine member of the prior art; - Figure 4 shows an alternative of Figure 3, according to an identical view, but of another turbomachine member of the prior art; - Figures 5,7,8 show, in a view identical to those of Figures 3,4, three variants of a turbomachine zone according to the invention; and FIG. 6 schematizes the split annular downstream rod illustrated in FIGS.

With reference to FIGS. 1 to 4, the pre-existing state of the art, to which the invention provides an evolution and advantages, is described below. Although the invention can be adapted to different stages of a turbomachine, it is illustrated here when it is carried on a high pressure turbine stage. It is indeed within this environment that the invention is the most interesting. First, in the turbomachine 1 of a first prior art shown schematically in FIGS. 1-3, the rotor of the high-pressure turbine represented comprises several wheels 2 assembled axially to each other by annular flanges and each comprising a disc 3 carrying individual blades 4. The wheels 2 mounted rotating around the longitudinal axis 10 of the turbomachine are just downstream of a combustion chamber 20 and a high-pressure distributor 22, with fixed vanes 220, conventionally known in the prior art.

As is also visible in FIGS. 4-5, 7, 8, the blades 4 each have, radially, from the outside towards the inside, portions successively defining a blade 5, an internal platform 6, a median wall or stilt 7 and a foot 8. The housing cells of the feet 8 of the blades 4 define between them teeth which are surrounded by the platforms 6 of the blades 4.

The blades 5 extend radially outwardly from the disk, in a vein 50, and the inner ends of the legs 8 are engaged axially in the cells, the bottoms of which are referenced 30, of the outer periphery of the disk. The vanes are thus retained radially by teeth of the disc arranged alternately with said cells.

The inner platforms 6 extend laterally and are arranged circumferentially end to end so as to define together the internal limit of the flow flow of the hot gases flowing in the vein 50, upstream (AM) downstream (AV), following the meaning 11.

A downstream annular flange 9 is arranged downstream of the disc 3. This downstream flange is retained on the downstream face of the disc by an annular hook system 9a located at the radially inner end of the flange and cooperating with an annular hook 12 of the face downstream flange 9 comprises a radially outer annular lip 195 protruding upstream, located opposite, or abutting against the downstream radial ends of the platforms 6. This downstream flange also comprises a lip inner annulus 193 protruding upstream, located opposite, see bearing against the downstream faces of the teeth and feet 8 of the blades, radially between cavities of radially outer and inner cells, respectively. The inner lip 193 makes it possible to create a seal between these cavities of external and internal cavities, downstream of the disc. The outer lip 195 makes it possible to create a seal between the vein 50 and inter-blade cavities downstream of the blades. The downstream flange 9 also has the role of axially retaining the vanes 4 in the cavities of the disk 3.

In the example of FIGS. 1-3, the downstream flange 9 is maintained, towards its radially inner end, by a split annular downstream ring 11 disposed axially downstream of the blades and mounted elastically prestressed in an annular groove 13 of the hook 12 of the disc .

If we further detail as in Figure 3, the groove 13 defines a lower groove located radially inward with respect to an upper groove 15 of the disc which receives a radially inner end portion of the downstream flange 9.

The terms "lower" and "upper" are understood here in relation to the orientation of the drawing of the corresponding figure.

For its retention on the disk 3, the downstream flange 9 has, towards its radially inner end, a flange 90a oriented axially upstream and which is extended radially inwards by a radial shoulder 90b which, with the rim 90a, is engaged in the upper throat 15.

The shape of the upper groove 15 makes it open substantially axially downstream (AV), while the lower groove 13 opens substantially radially outwards, with lateral limits as a downstream radial edge 190 and an upstream radial edge 191 which also defines the radially inner edge of the upper groove 15.

For the downstream flange 9, and towards the radially inner end thereof, the downstream rod 11 ensures: - a radial stop by engagement of the downstream flange with the substantially axial shoulder 21 of the radially outer edge of the upper groove 15, - and an axial stop by engagement of the rod 11 with the upstream radial face of the downstream radial edge 190 of the lower groove 13. Thus placed, this downstream rod axially blocks the radial shoulder 90b of the flange 9 which bears against it.

An upstream flange 27 is also arranged upstream of the disc 3. This flange has an annular hook 28 in engagement with an annular hook 31 of the upstream face of the disc, and the inner end of the flange 27 is further connected by a bolted connection 29 to an upstream flange 33 of the disc (see Figure 2). The radially outer end of the flange 27 is arranged against the upstream faces of the teeth of the disc and the feet 8 of the blades 4, so that the upstream flange 27 axially retains the vanes 4 in the cavities of the disc. More particularly, the outer end of the upstream flange 27 comprises an annular lip 270 protruding downstream, which bears against the aforementioned upstream faces.

The upstream flange 27 further comprises wipers, cooperating with abradable blocks, thus forming a labyrinth type joint, the whole being not shown.

For performance it is, especially in connection with the downstream flange 9, the turbine disc 3 requires multiple machining operations and its manufacturing tolerances are tight. Research was therefore conducted to study the respective zones 9a and 12 of the downstream flange 9 and the disc 3.

This was also the case with regard to the solution adopted on another turbine of the prior art, that of a second prior art, as shown schematically in FIG.

In this version, for its retention on the disc 30, the downstream flange, here marked 900, has towards its radially inner end again a flange 90a oriented axially upstream and which is extended radially inwards by a radial shoulder 90b which, with the flange 90a, is engaged in the upper groove 150.

There is a radial stop of the downstream flange 900 by the downstream rod 110, towards the radially inner end of the flange. In fact, the downstream rod 110 ensures engagement of the downstream flange with the substantially axial shoulder 210 of the radially outer edge of the upper groove 150. The downstream rod 110 also provides an axial stop by engagement with the upstream radial face of the radially downstream edge. 190a of the lower groove 130. Thus placed, the downstream rod axially blocks again the radial shoulder 90b of the downstream flange 900 which bears against it. It is in this context that it has been sought to simplify the geometry of the disc and / or downstream rod to make the machining easier, reduce the cost of parts related to machining. The embodiments of Figures 5,7,8 are solutions that go in this direction and which correspond to what the invention proposes.

Thus, in a first solution, as in FIG. 5, the rotor disk 300, which aims to replace the previous ones 3,30 in a mounting as in FIGS. 1-2, shows: - as said annular downstream flange, that marked 910, as said annular groove, that marked 151 which is open radially inwards, located in the downstream face 320 of the rotor disk, and extended downstream by a shoulder 35 extending radially inwards, and as said downstream rod, that identified 111, which has an annular groove 37 open radially outwardly and axially limited, on either side, by upstream edges 39a and downstream 39b, so that for the downstream flange 910 - said radial stop is ensured by engagement of the downstream flange with the shoulder 35 which thus extends the annular groove 151, - and said axial stop is provided by engagement of the downstream rod 111 with said shoulder, in the annular groove 151.

It will be noted that the annular groove 151 corresponds, in radial position, to the above upper grooves 15 and 150, but with a different orientation, in the direction that its downstream shoulder makes it open radially inwards. In addition, the disk is then, beyond this, without a throat smaller than the image of grooves 13, 130: in 320 (FIGS. 5, 7, 8), axially opposite, or facing, downstream rod 111 and radially further inward, the downstream wall 32 of the disc extends substantially in a radial plane.

The ring 111 is split (FIG. 6) to be resiliently mounted in the annular groove 151. The groove 37 defines a housing receiving the radially inner terminal annular hook, the latter taking the form of a flange 900a extending substantially axially and oriented upstream of the flange 910.

To promote the making of the aforementioned stops, it is furthermore recommended that the shoulder 35 extending the annular groove 151 has two, and preferably only two, 350,351 contact interfaces for retaining the downstream flange 910, respectively axially with the upstream edge 39a downstream rod 111 and, radially, with the flange 900a of the radially inner end of the downstream flange 910. Here again, it will be possible to note the simplification made possible by this end of the downstream flange 910 which has a simple rim 900a, and therefore with a L-shape, unlike the shapes respectively "T" and "S" two inflections 90a, 90b of the earlier solutions schematically Figures 3 and 4.

Opposite the two contact interfaces 350, 351, respectively the upstream edge 39a of the downstream rod 111 and the radially outer face of the end hook 900a of the downstream end plate 910 define substantially flat surfaces and / or are perpendicular to each other; the first radial, the second axial, like the interfaces 350,351.

Another way of defining or making this zone of stops of the downstream flange 910 could also be to consider: - that the annular groove 37 of the downstream rod 111 receives the radially inner end 900a of the downstream flange 910 (terminal annular hook zone) that the upstream edge 39a of the downstream rod 111 is engaged, radially, in the annular groove 151 and, axially, with the shoulder 35 extending this groove, and that the downstream edge 39b of the same downstream rod 111 is engaged axially with the downstream face 910a of said radially inner end 900a of the downstream flange 910 (see FIG. 5).

It will be noted that a ventilation space, receiving air from the cavities of cells, will be favorably reserved at 41 between the downstream face 32 of the disk and that upstream of the downstream plate 910, excluding the contacts of the lips 193, 195, and radially inward, preferably to the beginning of the hook 900a.

For a good balancing of the forces, it is moreover preferred that the bearing faces of the upstream edges 39a and downstream 39b of the downstream rod 111 are radial, as is the downstream face 910a.

It is also in this respect recommended that the annular groove 37 of the downstream rod has a U shape. This solution is simple, allows a good axial support between the groove bottom 353 and the radially innermost face of the end hook 900a of the flange. downstream 910. It makes it possible to complete the interest of the aforementioned radial orientations.

The recommendation will be the same if one uses the alternative version below of the invention, schematized therefore Figure 7 (see in particular enlarged part).

This variant of the preceding solution is identical thereto, except that the annular groove 151 has an annular slot 151a in which is engaged a bead 111a of the downstream rod 111.

Preferably, for the aforementioned balances, the engagement of the bead 111a will be axial.

If, as recommended, this bead 111a protrudes from the downstream face of the upstream edge 39a of the downstream rod 111, the slot 151a will be on the upstream radial face of the shoulder 35 of the disk 300.

In the other alternative version below of the invention, schematized in FIG. 8, the downstream edge 390b of the annular downstream ring 112, a priori split, must be radially shorter than the upstream edge 390a, which always surround an annular groove. 370 U-shaped of the ring.

As a particularity with respect to the two preceding solutions it should also be noted that the flange 900a oriented axially upstream of the radially inner end of the downstream flange 920 is now extended upstream and radially inwardly by a radial shoulder 910b engaged, radially inwards, in the annular groove 370 of the downstream rod 112 and, axially, with the downstream edge 390b of the downstream rod 112. The radial shoulder 910b defines the radially inner end of the downstream flange 920. The disk 300 may be that of the version of Figure 5, with the shoulder 35 without slot 151a. Parallel to the axis 10, the thickness e of the rod 112 can be reduced compared with that of the two previous solutions where the downstream axial wedging of the downstream flange is provided by engagement, against the downstream edge 39b of the downstream rod, of the face downstream 910a of the radially inner end of the downstream flange, before the inflection of the hook 900a. In this third solution, it is the shoulder or radial inner flange 910b which bears axially against the downstream edge 390b of the downstream rod 112. This will give a first consequent advantage of machining cost and a probable other advantage of gain. overall mass.

Claims (8)

1. Rotary assembly for a turbomachine supplied with air, the assembly comprising: a disk (300) of rotor of the turbomachine mounted rotating about an axis of rotation (10) and having: - cavities (30) retaining radial blade (4), - an upstream face and an opposite downstream face (32,320), - and at least one annular groove (151) located in the downstream face (32,320), the annular groove (151) being open radially towards the interior and extended downstream by a shoulder (35) extending radially inwardly, - vanes (4) mounted in said cells, - an annular downstream flange (910, 920) disposed axially downstream of the vanes, an annular downstream ring 111,112 disposed axially downstream of the vanes and mounted in said annular groove, ensuring, for the downstream flange, a radial stop and an axial stop, the downstream rod (111,112) having an annular groove (37,370) which is open radially outward and is axially limited on both sides by upstream (39a, 390a) and downstream (39b, 390b) edges, so that for the downstream flange: - said radial stop is ensured by engagement of the downstream flange with the shoulder ( 35) which extends the annular groove, - and said axial stop is ensured by engagement of the downstream rod (111, 112) with said shoulder, in the annular groove (151), characterized in that the downstream rod (111) has a bead (111a ) engaged in an annular slot (151a) of the annular groove (151). 2. The assembly of claim 1, wherein the shoulder extending the annular groove (151) has two contact interfaces for retaining the downstream flap (910,920), respectively axially with the upstream edge (39a, 390a) of the downstream rod (111,112). and radially with a flange (900a) oriented axially upstream of the radially inner end of the downstream flange (910, 920). An assembly according to claim 1 or 2, wherein; - The annular groove (37,370) of the downstream rod receives a radially lower end of the downstream flange (910,920), - the upstream edge (39a) of the downstream rod (111) is engaged radially in the annular groove (151) and axially with the Shoulder (35) extending this annular groove, - and the downstream edge (39b) of said downstream rod is engaged axially with a face (910a) of said radially lower end of the downstream flask (910). 4. An assembly according to one of the preceding claims, wherein the rotor disk (3,30) of the turbomachine is a high pressure turbine disk. 5. An assembly according to one of the preceding claims, wherein the annular groove (37,370) of the downstream rod (111,112) has a U-shape. 6. Turbomachine rotor disk fed with air, for the rotary assembly according to one of the preceding claims, the disk, which rotates about an axis of rotation (10), having: - cavities (30) of radial blade retainer (4), - an upstream face and an opposite downstream face on the side of which the disk has an annular groove (151) for receiving a downstream annular ring (111, 112) for stopping a downstream flange (910,920), the annular groove being open radially inward and extended by a bearing shoulder (35) of the downstream rod, the shoulder (35) extending radially inwardly. 7. downstream annular ring for the rotary assembly according to one of claims 1 to 5, said rod (111,112) having a U-shaped annular groove (37,370) for receiving a radially inner end of a downstream flange. (910,920) turbomachine rotor disk. 8. Turbomachine, such as a jet engine or a turboprop aircraft, characterized in that it comprises an assembly according to one of claims 1 to 5.