Sealing assembly and associated method

Abstract

The invention relates to a method for mounting a sealing assembly comprising a first ring sector (701) and a second ring sector (702), the first ring sector (701) comprising a first connecting face (70a) and the second ring sector (702) including a second connecting face (70b), the first connecting face (70a) including a first groove (75c) and the second connecting face (70b) including a second groove (75d) configured to be arranged peripherally facing one another so as to define a recess (76b) including an axial opening (77a) opening at an axial end of the sealing assembly when the assembly is mounted, the method comprising the following steps: - introducing (E1) a sealing tab (64b) into the first groove (75c), the first groove (75c) and the second groove (75d) not being peripherally aligned; - moving (E2) the second ring sector (702) relative to the first ring sector (701) in order to peripherally align the first groove (75c) and the second groove (75d), the alignment having the effect of blocking the sealing tab (64b) so as to prevent the sealing tab (64b) from escaping from the recess (76b) through the axial opening (77a).

Description

[0001] SEALING ASSEMBLY AND ASSOCIATED METHOD

[0002] TECHNICAL FIELD

[0003] The present invention relates to the field of turbines for turbomachines. It relates more particularly to a turbine stage for a turbomachine, such as an aircraft turbojet or turboprop.

[0004] In particular, the present invention relates to a method of mounting a sealing assembly for a turbomachine turbine, as well as an associated sealing assembly.

[0005] STATE OF THE ART

[0006] A turbomachine, in particular a twin-spool turbomachine, conventionally comprises, from upstream to downstream, depending on the direction of flow circulation in the turbomachine, a fan, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine and a low-pressure turbine.

[0007] The low-pressure turbine makes it possible to exploit and release the power generated in the combustion chamber and typically comprises several stages, each comprising an annular row of fixed blades carried by an external casing and a row of moving blades mounted to rotate around an axis of rotation of the turbomachine.

[0008] The moving blades rotate inside an annular structure or sectored ring attached to the external casing of the low-pressure turbine. This ring is formed of several ring sectors to overcome expansion problems of the assembly when it is subjected to high temperatures. These ring sectors, which extend circumferentially in an arc of a circle, are arranged circumferentially end to end and define a flow circulation vein. To ensure the sealing of this vein and limit the leakage of hot gas to the outside of the vein, the sectors arranged circumferentially end to end have grooves on the circumferentially facing faces in which one or more sealing tabs are arranged.

[0009] More specifically, such a sealing tab is flat and mounted partly in a groove of a connecting face of a ring sector and partly in a groove of a connecting face of a circumferentially adjacent ring sector, located opposite, said two grooves cooperating to form a housing. The sealing tab thus overlaps the inter-sector space between two circumferentially adjacent ring sectors and limits the passage of gas between the two ring sectors.

[0010] Each ring sector can include several grooves so as to form several housings, each accommodating a sealing tab.

[0011] Each of the grooves of a connecting face of a ring sector can be located in strategically chosen areas of the ring sector in order to maximize the gain in sealing after positioning the sealing tabs in the corresponding housings formed by the grooves.

[0012] However, during operation of the turbomachine, vibrations or forces can cause downstream displacements of the sealing tab which can escape from the housing in which it is mounted. In addition to the loss of the escaped sealing tabs, this leak can have significant consequences, particularly at the level of the external casing of the low-pressure turbine which can be damaged due to contact with the sealing tabs escaped from their housing. In addition, the escape of a sealing tab causes a significant local thermal impact (estimated at a transient increase of 65°C). As a consequence, the service life of the numerous parts in this area of ​​the turbine can be reduced due to the loss of one of these sealing tabs.

[0013] The loss of a sealing tab, in addition to the potential damage caused to the turbomachine, generates additional costs for disassembly and reassembly of the turbomachine in order to recover the tab and replace it.

[0014] To avoid this, depending on the positioning of the grooves, the sealing tab received in the corresponding housing can be retained in said housing in different ways.

[0015] For example, the sealing tab mounted in a housing can be retained there by the presence of a stop formed by a part of the turbomachine blocking an inlet of the housing, when this is mechanically possible. However, this solution is not entirely satisfactory because it restricts the positioning of the grooves forming the housing and therefore of the sealing tabs.

[0016] Furthermore, this solution is not applicable to all the housings, and there remain housings on the connecting faces of two ring sectors requiring the presence of a sealing tab which cannot be closed by another part of the turbomachine, which therefore does not prevent the sealing tab from escaping.

[0017] EXPOSED

[0018] An aim of the present invention is to remedy the aforementioned drawbacks, by proposing a sealing assembly making it possible to maintain the seal between the different sectors of a ring while allowing easy assembly of the sealing tabs and an associated assembly method.

[0019] More specifically, the invention aims to propose a sealing assembly preventing the escape of a sealing tab, as well as an associated mounting method.

[0020] To this end, according to a first aspect, a method is proposed for mounting a sealing assembly, the sealing assembly being centered on an axis, and comprising a first ring sector and a second ring sector intended to be arranged circumferentially end to end around the axis, the first ring sector comprising a first connecting face and the second ring sector comprising a second connecting face configured to be arranged circumferentially opposite the first connecting face when the first ring sector and the second ring sector are arranged circumferentially end to end around the axis, the first connecting face comprising a first groove and the second connecting face comprising a second groove, the first groove and the second groove being configured to be arranged circumferentially opposite one another so as to define a housing,the housing comprising an axial opening which opens at an axial end of the sealing assembly when the sealing assembly is mounted, the method comprising the following steps:,

[0021] - introduction of a sealing tab into the first groove, the first groove and the second groove being circumferentially offset relative to each other;

[0022] - moving the second ring sector relative to the first ring sector to circumferentially align the first groove and the second groove with each other, the alignment of the first groove with the second groove having the effect of blocking the sealing tab so as to prevent the sealing tab from escaping from the housing through the axial opening.

[0023] In a particular embodiment, the sealing tab is introduced circumferentially into the first groove, the second ring sector then being moved axially relative to the first ring sector to introduce the sealing tab into the second groove until the second groove is circumferentially aligned with the first groove, the sealing tab then being completely introduced into the second groove, the sealing tab being held axially in the first groove during said movement by a first stop delimiting the axial opening.

[0024] In another particular embodiment, the sealing tab is introduced axially into the first groove and into the second groove simultaneously, the second ring sector then being displaced radially relative to the first ring sector to circumferentially align the second groove with the first groove.

[0025] Advantageously, in this other particular embodiment, the first ring sector comprises a first stop housed in the first groove and the second ring sector comprises a second stop housed in the second groove such that, after introduction of the sealing tab into the first groove and the second groove simultaneously and displacement in a radial direction of the second ring sector relative to the first ring sector, the sealing tab is held axially by shear by the first stop and by the second stop.

[0026] Preferably still in this other particular embodiment, when introducing the sealing tab axially into the first groove and the second groove, the first ring sector and the second ring sector are offset relative to each other so that a first space not occupied by the first stop in the first groove and a second space not occupied by the second stop in the second groove are at least circumferentially aligned with each other, allowing the simultaneous insertion of the sealing tab into the first unoccupied space and into the second unoccupied space, and after radial displacement of the second ring sector relative to the first ring sector, the first unoccupied space and the second unoccupied space are no longer circumferentially aligned and the sealing tab is held by shear between the first stop and the second stop.

[0027] The invention also relates, according to a second aspect, to a sealing assembly for a turbomachine, comprising: a first ring sector and a second ring sector which are arranged circumferentially end-to-end around the axis, the first ring sector comprising a first connecting face and the second ring sector comprising a second connecting face arranged opposite the first connecting face, the first connecting face comprising a first groove and the second connecting face comprising a second groove, the first groove and the second groove being arranged circumferentially opposite one another so as to form a housing comprising an unobstructed axial opening which opens at an axial end of the sealing assembly,a sealing tab mounted in the housing so as to provide a seal between the circumferentially adjacent first ring sector and second ring sector, the first groove comprising a first stop and the second groove comprising a second stop, the first stop being formed by an inner wall of the first groove and the second stop being formed by an outer wall of the second groove, the sealing tab being inserted into the housing radially between the first stop and the second stop, the first stop and the second stop holding the sealing tab in the housing by shearing.,

[0028] Advantageously, the first stop defines between itself and the radially outer wall a first free radial space, and the second stop defines between itself and the radially inner wall a second free radial space, the first free radial space being arranged radially outside the second free radial space.

[0029] The invention finally relates, according to a third aspect, to a sealing assembly for a turbomachine, comprising: a first ring sector and a second ring sector arranged circumferentially end-to-end around the axis, the first ring sector comprising a first connection face and the second ring sector comprising a second connection face arranged circumferentially opposite the first connection face, the first connection face comprising a first groove and the second connection face comprising a second groove, the first groove and the second groove being arranged circumferentially opposite one another so as to form a housing comprising an unobstructed axial opening which opens out at an axial end of the sealing assembly,a sealing tab mounted in the housing so as to provide a seal between the circumferentially adjacent first ring sector and second ring sector, the first groove comprising a first stop and the second groove comprising a second stop, the first stop and the second stop reducing the axial opening so that the sealing tab cannot escape through said axial opening by being axially blocked by both the first and second stops.,

[0030] Advantageously, the first stop and the second axial stop have identical dimensions and are arranged symmetrically with respect to a longitudinal plane comprising the axis and extending opposite the first connecting face and the second connecting face.

[0031] Preferably, the first stop and the second stop are rectangular. DESCRIPTION OF THE FIGURES

[0032] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0033] Figure 1 illustrates a sectional view of a turbomachine according to one embodiment of the invention;

[0034] Figure 2 illustrates a sectional view of a low pressure turbine comprising a sealing assembly according to one embodiment of the invention; and

[0035] Figure 3 schematically illustrates a detailed view in section along a longitudinal plane of an interface between two ring sectors of a part of the turbine of Figure 2;

[0036] Figure 4 schematically illustrates, in sectional view along a radial plane, a first housing of the interface between two ring sectors of Figure 3;

[0037] Figure 5 schematically illustrates, in sectional view along a radial plane, a second housing of the interface between two ring sectors of Figure 3 according to a first embodiment;

[0038] Figure 6 schematically illustrates, in sectional view along a radial plane, a first housing of the interface between two ring sectors of Figure 3 according to a second embodiment;

[0039] Figures 7A and 7B illustrate different steps of a method of mounting the sealing assembly according to the first embodiment of the invention;

[0040] Figures 8A, 8B and 8C illustrate different steps of a method of mounting the sealing assembly according to the second embodiment of the invention; and

[0041] Figure 9 schematically illustrates the different steps of a method of mounting a sealing assembly according to an embodiment of the invention.

[0042] Throughout the figures, similar elements have identical references.

[0043] DETAILED DESCRIPTION

[0044] Figure 1 illustrates a turbomachine 100, in particular a twin-spool turbomachine, conventionally comprising, from upstream to downstream, according to the direction of circulation of the flow in the turbomachine represented by an axis X, a fan 110, a low-pressure compressor 120, a high-pressure compressor 130, a combustion chamber 140, a high-pressure turbine 150 and a low-pressure turbine 160.

[0045] By convention, in the present application, the terms "upstream" and "downstream" are defined relative to the direction of air flow in the turbomachine. Similarly, by convention in the present application, the terms "inner" and "outer", "lower" and "upper", "inner" and "outer" are defined radially relative to the X axis of the turbomachine.

[0046] As shown in Figure 2, the turbomachine turbine 160 comprises several axially successive stages, each comprising an upstream distributor 2 and a downstream bladed wheel 3, and a sealing assembly specific to each stage.

[0047] Each distributor 2 comprises a radially internal annular platform 21 and a radially external annular platform 22 coaxial, between which extend radial or substantially radial blades 23, regularly spaced circumferentially over the entire circumference of said platforms. The distributor 2 is mounted on an external casing 4 of the turbine 160.

[0048] As best seen in Figure 3, which shows a detailed view of the part of Figure 2 framed in dotted lines, the outer annular platform 22 comprises at its upstream end, a radially outer spoiler 221 and a radially inner spoiler 222 which both extend upstream. These two edges extend on either side of an annular groove 223 open upstream AM.

[0049] The set of 2 distributors forms the fixed part of the engine called the "stator".

[0050] Each bladed wheel 3 comprises a disc 30 carrying at its external periphery radial or substantially radial blades 31, the discs 30 of the different wheels being connected coaxially to each other and to a drive shaft by appropriate means, so as to form the "rotor" of the turbine 160 (see figure 3).

[0051] The blades 31 rotate inside a sealing ring, or sectored ring 7, of the sealing assembly. The sealing ring 7 is located between a first distributor and a second distributor, and forms an annular structure extending around the longitudinal axis X, and having the longitudinal axis X as its axis of revolution. The corresponding sealing assembly and its sealing ring 7 are thus centered around the axis X.

[0052] When the turbine 160 is in operation, the impeller 3 rotates inside the sealing ring 7. This sealing ring 7 which extends around the impeller 3 is fixed to the external casing 4 of the turbine 160. This sealing ring 7 is formed of several ring sectors 70, circumferentially adjacent and arranged end to end, each being fixed to the external casing 4 of the turbine 160. Each ring sector 70 is therefore in an arc of a circle, the two ends of which form for one a first connection face 70a and for the other a second connection face 70b. Each of the first connecting face 70a and the second connecting face 70b extends in a plane passing through the longitudinal axis X, the first connecting face 70a of a first ring sector 701 being circumferentially adjacent to a second connecting face 70b of a second ring sector 702 circumferentially adjacent.The first connecting face 70a and the second connecting face 70b are thus configured to be arranged circumferentially opposite each other.

[0053] Figure 3 illustrates an example of a first connecting face 70a of a first ring sector 701. The second connecting face 70b of a second ring sector 702 circumferentially adjacent to the first ring sector 701 is not visible in Figure 3, but is identical unless otherwise indicated.

[0054] The ring sectors 70 each carry radially towards the inside thereof a block of abradable material 71. This block of abradable material is configured to cooperate by friction with annular wipers 32 arranged at the radially external periphery of the blade 31 of the rotor which is located opposite (see figure 2).

[0055] Each ring sector 70 comprises, on a radially external surface, an annular groove portion 72 radially open towards the outside. When the different ring sectors 70 are assembled, these groove portions together define a circumferential annular groove 72, in which a downstream annular rail 40 of the external casing 4 is engaged, so as to ensure fixing to the external casing 4. The external casing 4 comprises a downstream annular rail 40 for each sectored ring 7.

[0056] The downstream annular rail 40 and the downstream ends of the different ring sectors 70 are held in a radial direction (i.e. from bottom to top and from top to bottom in FIG. 3) by the internal 222 and external 221 spoilers of the external platform 22.

[0057] Furthermore, each ring sector 70 comprises at its upstream end, a circumferential member 73 with a C-shaped section, which is engaged axially from downstream on an upstream annular rail 41 of the outer casing 4. The circumferential member 73 is only partially visible in FIG. 3.

[0058] Each ring sector 70 comprises on its first connection face 70a at least one groove 75 cooperating with a groove 75 of the second connection face 70b of the circumferentially adjacent ring sector 70 to form a housing 76, the two grooves 75 being located opposite one another when the two ring sectors 70 are mounted on the external casing 4.

[0059] In particular in the example illustrated in Figure 3, the first ring sector 701 comprises on its first connection face 70a a first groove 75a. This first groove 75a forms a first part of a first housing 76a as illustrated in Figure 4.

[0060] Referring to Figure 4, a second groove 75b is formed on the second connecting face 70b of the circumferentially adjacent second ring sector 702, such that the first groove 75a and the second groove 75b cooperate to form the first housing 76a. As illustrated in Figure 3, the first housing 76a may extend along an outer surface of the ring sectors 701, 702 facing the outer casing 4. The sealing assembly comprises a first sealing tab 64a which is disposed in the first housing 76a.

[0061] The first housing 76a is not open because the opening of the first housing 76a is blocked by another part, in this case by the downstream annular rail 40, which makes it possible to prevent the first sealing tab 64a from escaping from the first housing 76a, once the sealing assembly is mounted in the turbine 160. This first housing 76a is therefore not problematic in terms of assembly and operation, because the first sealing tab 64a is necessarily held in the first housing 76a.

[0062] Furthermore, the first connecting face 70a of the first ring sector 701 comprises a third groove 75c forming part of a second housing 76b. Similarly, the second connecting face 70b of the circumferentially adjacent second ring sector 702 comprises a fourth groove 75d circumferentially aligned and facing the third groove 75c, the second housing 76b being formed by the cooperation of the third and fourth grooves 75c and 75d (see Figure 5 and Figure 6).

[0063] The sealing assembly includes a second sealing tab 64b inserted into the second housing 76b. The second sealing tab 64b is defined when inserted into the second housing 76b by a radial dimension (or thickness), a circumferential dimension (or width), and an axial dimension (or length).

[0064] The second housing 76b, in the example shown in FIG. 3, opens towards the downstream of the turbine 160. In other words, the third groove 75c and the fourth groove 75d both open towards the downstream of the turbine 160, so that the second housing 76b has a downstream opening 77a not blocked by another part. The second housing 76b, and therefore the third and fourth grooves 75c and 75d, are formed in the downstream part of their respective ring sector 701, 702, radially inwards relative to the groove portion 72.

[0065] As can be seen in Figure 3, the second housing 76b comprises a radially outer wall 77b, a radially inner wall 77c, and a bottom wall 77d connecting the radially outer wall 77b and the radially inner wall 77c. The bottom wall 77d is located opposite the axial opening 77a which forms a mouth of the second housing 76b. The bottom wall 77d extends substantially radially relative to the longitudinal axis X, while the radially inner wall 77c and the radially outer wall 77b extend around the longitudinal axis X. Furthermore, as visible in FIGS. 5 and 6 which respectively represent an example of a first embodiment and a second embodiment of the second housing 76b, the second housing 76b comprises a first circumferential wall 77e delimiting the third groove 75c and a second circumferential wall 77f delimiting the fourth groove 75d.

[0066] The first circumferential wall 77e and the second circumferential wall 77f each radially connect the radially outer wall 77b to the radially inner wall 77c. The first circumferential wall 77e and the second circumferential wall 77f further extend axially between the axial opening 77a and the bottom wall 77d.

[0067] The second circumferential wall 77f is opposite and extends opposite the first circumferential wall 77e, when the first ring sector 701 and the second ring sector 702 are assembled to form the second housing 76b. The first circumferential wall 77e and the second circumferential wall 77f define between them a spacing greater than the width of the second sealing tab 64b, for example to allow parts such as the tab the freedom to expand in operation.

[0068] Unlike the first housing 76a, the second housing 76b is not closed, the axial opening 77a not being blocked by a third part.

[0069] In order to maintain the second sealing tab 64 in the second housing 76b, the third groove 75c comprises a first stop 78a and the fourth groove 75d comprises a second stop 78b, an example of a first embodiment of which is illustrated in FIG. 5, and an example of a second embodiment is illustrated in FIG. 6. These two embodiments will now be described.

[0070] 1 er method of implementation:

[0071] Figure 5 illustrates in radial sectional view (along a plane perpendicular to the longitudinal axis X) a second housing 76b according to a first embodiment. In this first embodiment, the first stop 78a extends in the third groove 75c from the radially inner wall 77c towards the radially outer wall 77b. The first stop 78a defines between it and the radially outer wall 77b a first free radial space 79a.

[0072] The second stop 78b extends in the fourth groove 75d from the radially outer wall 77b towards the radially inner wall 77c, and likewise defines between it and the radially inner wall 77c a second free radial space 79b.

[0073] The first stop 78a comprises an external radial surface 80a of the same circumferential surface as the third groove 75c, that is to say that the first stop 78a extends circumferentially between the first circumferential wall 77e and the first connecting face 70a of the first ring sector 701. The first stop 78a extends in contact with the radially internal wall 77c.

[0074] Likewise, the second stop 78b comprises an internal radial surface 80b, of the same circumferential surface as the fourth groove 75d, that is to say that the first stop 78a extends circumferentially between the second circumferential wall 77f and the second connecting face 70b of the second ring sector 702. The second stop 78b extends radially in contact with the radially external wall 77b.

[0075] The first free radial space 79a is arranged radially outside the second free radial space 79b.

[0076] The second sealing tab 64b is disposed in the second housing 76b between the first stop 78a and the second stop 78b. More specifically, the second sealing tab 64b comprises a first radial face in contact with the external radial surface 80a of the first stop 78a and a second radial face opposite the first radial face, in contact with the internal radial surface 80b of the second stop 78b, such that the second sealing tab 64b is held in the second housing 76b between the two stops 78a and 78b. More specifically, the two stops 78a and 78b exert on the second sealing tab 64b a shear force which blocks the second sealing tab 64b in the second housing 76b.

[0077] The outer radial surface 80a of the first stop 78a and the inner radial surface 80b of the second stop 80b are radially spaced from each other by a thickness of between 95 and 105% of the thickness of the second sealing tab 64b.

[0078] In this way, the second sealing tab 64b is held in the second housing 76b by shear and friction exerted by the first stop 78a and the second stop 78b.

[0079] 2 ême method of implementation:

[0080] Figure 6 illustrates a sectional view along a radial plane (along a plane perpendicular to the axis X) of the second housing 76b according to a second embodiment. In this second embodiment, the first stop 78a and the second stop 78b are symmetrical with respect to a longitudinal plane, passing through the longitudinal axis X of the turbomachine, and extending opposite the first connecting face 70a and the second connecting face 70b. The plane of symmetry is parallel and equidistant from the first connecting face 70a and the second connecting face 70b. Preferably, the first stop 78a and the second stop 78b have identical dimensions and are for example rectangular. More precisely, the first stop 78a is formed in the third groove 75c at the axial opening 77a. The first stop 78a more particularly defines a circumferential restriction of the axial opening 77a.The first stop 78a extends circumferentially between the first circumferential wall 77e and a first circumferential end 81a. In other words, the first stop 78a extends parallel to the bottom wall 77d.

[0081] The first circumferential end 81a is separated from the second circumferential wall 77f by a distance greater than or equal to the width of the second sealing tab 64b. This allows the mounting of the sealing assembly, which will be described in more detail later.

[0082] Furthermore, the first stop 78a radially connects the radially outer wall 77b and the radially inner wall 77c, so as to block an axial movement of the second sealing tab 64b towards the axial opening 77a.

[0083] Finally, the first stop 78a extends axially over a small distance, of the order of a few millimeters. In any event, the second sealing tab 64b has a length less than the axial distance between the first stop 78a and the bottom wall 77d.

[0084] Similarly, the second stop 78b is formed in the fourth groove 75d at the axial opening 77a. More specifically, the second stop 78b defines a circumferential restriction of the axial opening 77a. The second stop 78b extends between the second circumferential wall 77f and a second circumferential end 71b. In other words, the second stop 78b extends parallel to the bottom wall 77d.

[0085] The second circumferential end 81b is separated from the first circumferential wall 77e by a distance greater than or equal to the width of the second sealing tab 64b. This allows the mounting of the sealing assembly, which will be described in more detail later.

[0086] Furthermore, the second stop 78b radially connects the radially outer wall 77b and the radially inner wall 77c, so as to block an axial movement of the second sealing tab 64b towards the axial opening 77a.

[0087] Finally, the second stop 78b extends axially over a small distance, of the order of a few millimeters, preferably identical to the first stop 78a. In any event, the second sealing tab 64b has a length less than the axial distance between the second stop 78b and the bottom wall 77d.

[0088] The first stop 78a and the second stop 78b are circumferentially aligned and thus restrict the circumferential dimension of the axial opening 77a. More specifically, the distance between the first circumferential end 81a of the first stop 78a and the second circumferential end 81b of the second stop 78b is less than the width of the second sealing tab 64b, as illustrated in FIG. 6.

[0089] Thus, the second sealing tab is retained in the second housing 76b between the first stop and the second stop 78a and 78b on the one hand and the bottom wall 77d on the other hand.

[0090] Method of mounting the sealing assembly:

[0091] In Figure 9, the different stages of a method of mounting the sealing assembly previously described are schematically illustrated.

[0092] Figures 7A and 7B illustrate steps for mounting a sealing assembly according to the first embodiment of Figure 5.

[0093] In a first step E1 (illustrated in FIG. 7A), the second sealing tab 64b is introduced into the third groove 75c of the first ring sector 701. During this first step E1, the third groove 75c and the fourth groove 75d are not circumferentially aligned (and therefore likewise the first ring sector 701 and the second ring sector 702 are not circumferentially aligned).

[0094] As illustrated in Figure 7A, step E1 is implemented while the third groove 75c and the fourth groove 75d (and therefore the two ring sectors 701 and 702) are radially offset such that the first free radial space 79a and the second free radial space 79b are circumferentially aligned at least partially, over a radial distance greater than the thickness of the second sealing tab 64b, so as to be able to axially introduce said second sealing tab 64b. Such an alignment situation is illustrated in Figure 7A.

[0095] Step E1 consists in this first embodiment of axially introducing the second sealing tab 64b into the parts of the first free radial space 79a and of the second free radial space 79b aligned with each other. The second sealing tab 64b is then inserted simultaneously into the third and fourth grooves 75c and 75d.

[0096] In a second step E2 (illustrated in FIG. 7B), the second ring sector 702 is moved relative to the first ring sector 701 to circumferentially align the third groove 75c and the fourth groove 75d.

[0097] More specifically, step E2 consists in this first embodiment of a radial displacement of the second ring sector 702 relative to the neighboring first ring sector 701. Figure 7B illustrates the second housing 76b at the end of step E2. When the third groove 75c and the fourth groove 75d are circumferentially aligned, the first free radial space 79a and the second free radial space 79b no longer have aligned parts, the second sealing tongue 64b then being held axially by shear by the first stop 78a and by the second stop 78b, which prevents it from escaping from the second housing 76b through the axial opening 77a.

[0098] In a third step E3, the sectored ring 7 comprising the two adjacent ring sectors 701 and 702 is fixed to the external casing 4, as illustrated in FIG. 5.

[0099] In a fourth step E4, the distributor 2 downstream of the impeller 3 surrounded by the sectored ring 7 can be mounted on the external casing 4.

[0100] Figure 9 illustrates steps E1 to E4.

[0101] Figures 8A to 8C illustrate steps for mounting a sealing assembly according to the second embodiment of Figure 6.

[0102] According to a step E1 (illustrated in FIG. 8A), the second sealing tab 64b is introduced only into the third groove 75c of the first ring sector 701 first. The introduction of the second sealing tab 64b can for example be done in a circumferential direction, so as to position the second sealing tab 64b between the bottom wall 77d and the first stop 78a, in contact with the first circumferential wall 77e. FIG. 8A illustrates the introduction of the second sealing tab 64b into the third groove 75c, and FIG. 8B illustrates the second tab 64b introduced into the third groove 75c at the end of the first step E1. FIGS. 8A and 8B illustrate a perspective and sectional view of the first groove 75c and the second sealing tab 64b.

[0103] According to a second step E2 (illustrated in FIG. 8C), the second ring sector 702 is moved axially relative to the first ring sector 701 comprising the third groove 75c in which the second sealing tab 64b is inserted. The axial movement of the second ring sector 702 is made from upstream to downstream so that the walls of the fourth groove 75d of the second ring sector 702 come to surround the sealing tab in the second groove progressively until the third groove 75c is circumferentially aligned with the fourth groove 75d. Such a movement is illustrated in FIG. 8C.

[0104] The axial displacement of the second ring sector 702 is carried out while the second connecting face 70b of the second ring sector 702 is at a circumferential distance from the first connecting face 70a of the first ring sector 701 corresponding to the distance between said two connecting faces 70a and 70b once the ring 7 is assembled, this distance being for example zero or less than a few millimeters. The second sealing tongue 64b being positioned in the third groove 75c in contact with the first circumferential wall 77e, it extends circumferentially sufficiently little so as not to block the displacement of the second ring sector 702 by coming into contact with the second stop 78b.

[0105] When the third groove 75c and the fourth groove 75d are circumferentially and axially aligned, the sealing tab 64b is then completely inserted into the fourth groove 75d which at this moment forms the second housing with the third groove 75c. Similarly, the first stop 78a and the second stop 78b are then circumferentially aligned with each other, and restrict the axial opening 77a so as to prevent the second sealing tab 64b from escaping from the second housing 76b through the axial opening 77a.

[0106] In a third step E3, the sectored ring 7 comprising the two circumferentially adjacent ring sectors 701 and 702 is fixed to the external casing 4, as illustrated in FIG. 6.

[0107] In a fourth step E4, the distributor 2 downstream of the impeller 3 surrounded by the sectored ring 7 can be mounted on the external casing 4.

[0108] Steps E3 and E4 of the second embodiment are identical to steps E3 and E4 of the first embodiment.

Claims

CLAIMS 1. Method for mounting a sealing assembly, the sealing assembly being centered on an axis (X), and comprising a first ring sector (701) and a second ring sector (702) intended to be arranged circumferentially end to end around the axis (X), the first ring sector (701) comprising a first connecting face (70a) and the second ring sector (702) comprising a second connecting face (70b) configured to be arranged circumferentially opposite the first connecting face (70a) when the first ring sector (701) and the second ring sector (702) are arranged circumferentially end to end around the axis (X), the first connecting face (70a) comprising a first groove (75c) and the second connecting face (70b) comprising a second groove (75d),the first groove (75c) and the second groove (75d) being configured to be arranged circumferentially opposite each other so as to define a housing (76b), the housing (76b) comprising an axial opening (77a) which opens at an axial end of the sealing assembly when the sealing assembly is mounted, the method comprising the following steps:, - introduction (E1) of a sealing tab (64b) into the first groove (75c), the first groove (75c) and the second groove (75d) being circumferentially offset relative to each other; - displacement (E2) of the second ring sector (702) relative to the first ring sector (701) to circumferentially align the first groove (75c) and the second groove (75d) with each other, the alignment of the first groove (75c) with the second groove (75d) having the effect of blocking the sealing tab (64b) so as to prevent the sealing tab (64b) from escaping from the housing (76b) through the axial opening (77a), in which the sealing tab (64b) is introduced (E1) circumferentially into the first groove (75c), the second ring sector (702) then being axially displaced relative to the first ring sector (701) to introduce the sealing tab (64b) into the second groove (75d) until the second groove (75d) is circumferentially aligned with the first groove (75c), the sealing tab (64d) then being fully inserted into the second groove (75d),the sealing tongue (64d) being held axially in the first groove (75c) during said movement (E2) by a first stop (78a) delimiting the axial opening (77a)., 2. Method for mounting a sealing assembly, the sealing assembly being centered on an axis (X), and comprising a first ring sector (701) and a second ring sector (702) intended to be arranged circumferentially end to end around the axis (X), the first ring sector (701) comprising a first connecting face (70a) and the second ring sector (702) comprising a second connecting face (70b) configured to be arranged circumferentially opposite the first connecting face (70a) when the first ring sector (701) and the second ring sector (702) are arranged circumferentially end to end around the axis (X), the first connecting face (70a) comprising a first groove (75c) and the second connecting face (70b) comprising a second groove (75d), the first groove (75c) and the second groove (75d) being configured to be arranged circumferentially opposite one another so as to define a housing (76b), the housing (76b) comprising an axial opening (77a) which opens at an axial end of the sealing assembly when the sealing assembly is mounted, the method comprising the following steps: - introduction (E1) of a sealing tab (64b) into the first groove (75c), the first groove (75c) and the second groove (75d) being circumferentially offset relative to each other; - moving (E2) the second ring sector (702) relative to the first ring sector (701) to circumferentially align the first groove (75c) and the second groove (75d) with each other, the alignment of the first groove (75c) with the second groove (75d) having the effect of blocking the sealing tab (64b) so as to prevent the sealing tab (64b) from escaping from the housing (76b) through the axial opening (77a), wherein the sealing tab (64b) is introduced axially into the first groove (75c) and into the second groove (75d) simultaneously, the second ring sector (702) then being moved radially relative to the first ring sector (701) to circumferentially align the second groove (75d) with the first groove (75c).

3. Method according to claim 2, wherein the first ring sector (701) comprises a first stop (78a) housed in the first groove (75c) and the second ring sector (702) comprises a second stop (78b) housed in the second groove (75d) such that, after introduction (E1) of the sealing tab (64d) into the first groove (75c) and the second groove (75d) simultaneously and the displacement (E2) in a radial direction of the second ring sector (702) relative to the first ring sector (701), the sealing tab (64d) is held axially by shear by the first stop (78a) and by the second stop (78b).

4. Method according to claim 3, wherein, during the introduction (E1) of the sealing tongue (64b) axially into the first groove (75c) and the second groove (75d), the first ring sector (701) and the second ring sector (702) are offset. radially relative to each other such that a first unoccupied space (79a) by the first stop (78a) in the first groove (75c) and a second unoccupied space (79b) by the second stop (78b) in the second groove (75d) are at least circumferentially aligned with each other, allowing the simultaneous insertion (E1) of the sealing tab (64b) into the first unoccupied space (79a) and into the second unoccupied space (79b), and after radial displacement (E2) of the second ring sector (702) relative to the first ring sector (701), the first unoccupied space (79a) and the second unoccupied space (79b) are no longer circumferentially aligned and the sealing tab (64b) is held by shear between the first stop (78a) and the second stop (78b).

5. Sealing assembly for a turbomachine (100), comprising: a first ring sector (701) and a second ring sector (702) which are arranged circumferentially end-to-end around the axis (X), the first ring sector (701) comprising a first connecting face (70a) and the second ring sector (702) comprising a second connecting face (70b) arranged opposite the first connecting face (70a), the first connecting face (70a) comprising a first groove (75c) and the second connecting face (70b) comprising a second groove (75d), the first groove (75c) and the second groove (75d) being arranged circumferentially opposite one another so as to form a housing (76b) comprising an unobstructed axial opening (77a) which opens at an axial end of the sealing assembly,a sealing tab (64b) mounted in the housing (76b) so as to provide a seal between the circumferentially adjacent first ring sector (701) and second ring sector (702), the first groove (75c) comprising a first stop (78a) and the second groove (75d) comprising a second stop (78b), the first stop (78a) extending radially from a radially inner wall (77c) of the first groove (75c) and the second stop (78b) extending radially from a radially outer wall (77b) of the second groove (75d), the sealing tab (64b) being inserted into the housing (76b) radially between the first stop (78a) and the second stop (78b), the first stop (78a) and the second stop (78b) holding the sealing tab (64b) in the housing (76b) by shearing., 6. Sealing assembly according to claim 5, in which the first stop (78a) defines between it and the radially external wall (77b) a first free radial space (79a), and the second stop (78b) defines between it and the radially internal wall (77c) a second free radial space (79b), the first free radial space (79a) being arranged radially outside the second free radial space (79b).

7. Sealing assembly for a turbomachine (100), comprising: a first ring sector (701) and a second ring sector (702) arranged circumferentially end-to-end around the axis (X), the first ring sector (701) comprising a first connecting face (70a) and the second ring sector (702) comprising a second connecting face (70b) arranged circumferentially opposite the first connecting face (70a), the first connecting face (70a) comprising a first groove (75c) and the second connecting face (70b) comprising a second groove (75d), the first groove (75c) and the second groove (75d) being arranged circumferentially opposite one another so as to form a housing (76b) comprising an unobstructed axial opening (77a) which opens at an axial end of the assembly sealing, the housing comprising a radially outer wall (77b) and a radially inner wall (77c),a sealing tab (64b) mounted in the housing (76b) so as to provide a seal between the circumferentially adjacent first ring sector (701) and second ring sector (702), the first groove (75c) comprising a first stop (78a) and the second groove (75d) comprising a second stop (78b), the first stop (78a) connecting the radially outer wall (77b) and the radially inner wall (77c) and extending circumferentially to a first circumferential end (81a), the second stop (78b) connecting the radially outer wall (77b) and the radially inner wall (77c) and extending circumferentially to a second circumferential end (81b),the first stop (78a) and the second stop (78b) reducing a circumferential section of the axial opening (77a) so that the sealing tab (64b) cannot escape through said axial opening (77a) by being axially blocked by both the first stop and the second stop (78a, 78b) because the distance between the first circumferential end (81a) and the second circumferential end (81b) is less than a circumferential dimension of the sealing tab (64b)., 8. Sealing assembly according to claim 7, in which the first stop (78a) and the second stop (78b) have identical dimensions and are arranged symmetrically with respect to a longitudinal plane comprising the axis (X).

9. A sealing assembly according to claim 7 or 8, wherein the first stop (78a) and the second stop (78b) are rectangular.

Images