FR3078363A1 - MOBILE SEAL RING - Google Patents

Abstract

The invention relates to sealing (1) for a rotating part of a turbomachine, the mobile sealing ring (1) comprising: - an annular body (11) having a symmetry of revolution about a longitudinal axis (XX), - a ring flange (12) extending radially from the annular body (11), the ring flange (12) having a radially inner end (E) from which a portion of radially inner end (121) of the ring flange (12), the ring flange (12) comprising a radially outer end portion which connects the ring flange (12) to the annular body (11), mobile sealing ring (1) being characterized in that the ring flange (12) comprises at least one convex and / or concave portion (122, 123, 124) extending between the end portion radially outer ring flange (12) and the radially inner end portion of the ring flange (12).

Description

FIELD OF THE INVENTION

The invention relates to a movable sealing ring for a rotating part of a turbomachine.

The invention relates more specifically to the geometry of such a mobile sealing ring.

STATE OF THE ART

Document FR 2 953 250 discloses a mobile sealing ring for the turbine of a turbomachine.

Referring to Figure 1, the turbine comprises a distributor 5 formed of a plurality of fixed vanes 50 arranged in a flow stream 6, and a movable wheel placed behind the distributor 5. The movable wheel is formed 'a plurality of movable vanes 20, 30 also arranged in the flow stream 6 and mounted by their feet on discs 21, 31 of the first rotor 2 and of the second rotor 3.

The rotors 2, 3 are parts having a symmetry of revolution, and centered on a longitudinal axis X-X of the turbomachine. The rotors 2, 3 are assembled together by means of an upstream shell 33 of the second rotor 3, and of a downstream shell 23 of the first rotor 2 which are fixed to one another by a bolted connection 4 passing through fixing flanges 22, 32 of rotors 2.3. This assembly of rotors 2, 3 is itself connected to a turbine shaft (not shown) to be driven in rotation.

In addition, a mobile sealing ring carrying sealing wipers 110 is disposed at the junction between the successive rotors 2, 3, facing the corresponding fixed vane 50.

The movable sealing ring is fixed to the bolted connection 4 by means of a ring flange 12, and comprises a downstream retaining flange 113 bearing against the disc 31 of the rotor 3 downstream of said movable ring sealing.

The mobile sealing ring may also include an upstream flange 112 bearing against the disc 21 of the rotor 2 upstream of the mobile sealing ring.

The sealing wipers 110 of the movable sealing ring cooperate with the internal annular surface of the fixed vane 50 opposite said movable sealing ring, and thus ensure sealing between a successive upstream cavity and a downstream cavity of the flow stream 6 of the turbine.

However, the outer annular portion of the movable ring is subjected to very high temperatures due to the circulation of hot air within the flow stream 6. This results in a strong thermal gradient between the outer annular portion of the movable sealing ring and its internal annular portion. This gradient causes high stresses at the level of the fixing flanges 12, 22, 32. This phenomenon is more particularly illustrated in FIG. 2 which constitutes an enlargement of the external annular portion of the bolted connection 4 between:

the fixing flange 22 of the downstream shell 23 of the upstream rotor 2, the fixing flange 32 of the upstream shell 33 of the downstream rotor 3, and the fixing flange 12 of the movable ring disposed between the upstream rotor 2 and the rotor downstream 3.

In FIG. 2, the vertical arrow illustrates the direction and the direction of the mechanical stresses resulting from the thermal gradient in the mobile sealing ring which deforms. This results in creep of said movable sealing ring.

In addition, the bolted connection 4 is subjected to centrifugal forces linked to the rotation of the rotors 2, 3. These forces act on the screw crown of the bolted connection 4 which tends to extend radially so as to increase its radius which results in deformation of the flanges 22, 32 which can cause leaks.

The combined action of the thermal gradient and centrifugal forces can therefore lead to the phenomenon known as “flange opening” which reduces the life of the rotors 2, 3 of a turbomachine turbine. In FIG. 2, the horizontal arrows represent the phenomenon of the opening of the fixing flanges 22, 32 which accompanies creep.

There is therefore a need for a mobile sealing ring 1 for a rotating part of a turbomachine which does not have the drawbacks of the prior art.

DESCRIPTION OF THE INVENTION

One of the aims of the invention is to increase the life of the rotating parts of a turbomachine by limiting the phenomenon of flange opening at the junction between the successive rotors.

Another object of the invention is to allow better mechanical strength of the junction flanges of successive rotors of rotating parts of a turbomachine subjected to high thermal stresses.

Another object of the invention is to ensure the cooling of the discs of the rotating part of a turbomachine.

Another object of the invention is to provide sealing between the upstream and downstream cavities of the rotating part of a turbomachine.

Another object of the invention is to simplify the maintenance of the rotating parts of a turbomachine.

In this regard, the subject of the invention is a movable sealing ring for a rotating part of a turbomachine, said rotating part comprising:

- a first rotor comprising a first disc and a first fixing flange,

- a second rotor comprising a second disc and a second fixing flange,

a means of fixing the first fixing flange to the second fixing flange, the movable sealing ring comprising:

- an annular body having a symmetry of revolution about a longitudinal axis, said annular body being configured to extend between the first disc and the second disc,

a ring flange extending radially from the annular body, and configured to be fixed on the first fixing flange and / or on the second fixing flange, the ring flange having a radially internal end from which s extends a radially inner end portion of the ring flange, the ring flange comprising a radially outer end portion which connects the ring flange to the annular body, the movable sealing ring being characterized in that the ring flange comprises at least one convex and / or concave portion which extends between the radially external end portion of the ring flange and the radially internal end portion of the ring flange.

In such a movable sealing ring, the presence of a convex and / or concave portion of the ring flange promotes the conduction phenomenon within said ring flange. The thermal gradient is thus better distributed across the whole of the ring flange, which expands less at its radially internal portion. The radial force undergone by the fixing means is therefore reduced.

Advantageously, but optionally, the mobile sealing ring according to the invention can also comprise at least one of the following characteristics, taken alone or in combination:

- the convex and / or concave portion of the ring flange includes:

a first portion of curved shape, a second portion of curved shape, a curvature of the first portion being opposite to a curvature of the second portion,

- it also presents:

o an axial plane comprising the longitudinal axis, o a radial plane normal to the longitudinal axis, and passing through the fixing means, and o a fictitious point of intersection being defined as a point belonging to the axial plane, and which is situated at the intersection between the annular body and the radial plane, the ring flange having a curvilinear length in the axial plane, between the point of intersection and its radially internal end, which is greater than a length of a segment in said axial plane connecting said point of intersection and said radially internal end,

- the curvilinear length is greater than 1.5 times the length of the segment, and is up to 4 times the length of the segment,

- the annular body comprises sealing wipers extending radially outward relative to the ring flange,

- the radially outer end portion of the ring flange has, in the axial plane, a thickness greater than the thickness of the other portions of the ring flange,

- ventilation rings are formed in the ring flange, and

- The annular body includes a drain orifice.

The subject of the invention is also an assembly of a rotating part of a turbomachine, said assembly comprising:

- a first rotor comprising a first disc and a first fixing flange,

- a second rotor comprising a second disc and a second fixing flange,

a means for fixing the first fixing flange to the second fixing flange, and

a movable sealing ring as previously described, the annular body of the movable sealing ring extending between the first disc and the second disc, and the ring flange being fixed on the first fixing flange, and the second fixing flange at the fixing means.

The invention finally relates to a turbomachine comprising an assembly as previously described.

DESCRIPTION OF THE FIGURES

Other characteristics, objects and advantages of the invention will emerge from the description which follows, which is purely illustrative and not limiting, and which should be read with reference to the appended drawings in which:

FIG. 1, already described, represents an assembly for a turbine of a turbomachine known from the state of the art,

FIG. 2, also already described, illustrates a phenomenon of flange opening at the level of a bolted connection of turbomachine turbine rotors,

FIG. 3 illustrates a first exemplary embodiment of a mobile sealing ring according to the invention,

FIG. 4 illustrates a second embodiment of a movable sealing ring according to the invention, and

FIG. 5 illustrates a third embodiment of a movable sealing ring according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the figures, we will now describe a mobile sealing ring 1 for a rotating part of a turbomachine.

In what follows, the upstream and downstream are defined with respect to the direction of air flow in the turbomachine. In addition, the term radial means a direction radiating from a central point, or a central axis.

Rotating part of a turbomachine

With reference to FIGS. 3 to 5, a rotating part of a turbomachine comprises:

a first rotor 2 comprising a first disc 21 and a first fixing flange 22, a second rotor 3 comprising a second disc 31 and a second fixing flange 32, and a means 4 for fixing the first fixing flange 21 on the second mounting flange 31.

In general, such a rotating part is configured to be associated with a distributor 5 formed of a plurality of fixed vanes 50 arranged in a flow stream 6, the first rotor 2 and the second rotor 3 forming a movable wheel disposed on either side, upstream and downstream of the distributor 5 along a longitudinal axis XX of the turbomachine.

The rotors 2, 3 have a symmetry of revolution around the longitudinal axis X-X of the turbomachine. In general, such rotors 2, 3 comprise a set of blades fixed 20, 30, at their foot, to the discs 21, 31 of rotors 2, 3, said blades 20, 30 being distributed circumferentially around the axis. longitudinal XX of a turbomachine and also arranged in the flow stream 6.

In a preferred manner, the fastening means 4 comprises a bolted connection 4. The fastening flanges 22, 32 then each comprise a plurality of orifices (not shown) distributed circumferentially in a regular manner in the fastening flanges 22, 32, and intended to be placed facing each other when the first fixing flange 22 is fixed on the second fixing flange 32. Bolts are then threaded into the facing holes. This is not, however, limiting, since other fixing means 4 can also be envisaged.

As shown in FIGS. 3 to 5, in one embodiment, the first fixing flange 22 is connected to the first disc 21 by means of a downstream ferrule 23 of the first rotor 2, and the second fixing flange 32 is connected to the second disc 31 via an upstream ferrule 33 of the second rotor 3.

Movable sealing ring 1

Referring to Figures 3 to 5, the movable sealing ring 1 comprises: an annular body 11 configured to extend between the first disc 21 and the second disc 31, a ring flange 12 extending radially from the body annular 11, and configured to be fixed on the first fixing flange 22 and / or on the second fixing flange 32, for example at the level of the fixing means 4. Once the movable sealing ring 1 mounted within a rotating part of a turbomachine, such as that described above, the movable sealing ring 1 defines, with the first rotor 2 and the second rotor disc 3, an upstream ventilation cavity 7, and a downstream ventilation cavity 8, the ventilation cavities 7, 8 being separated from each other by the ring flange 12.

In operation, the ventilation cavities 7, 8 allow the circulation of fresh air taken from another point of the turbomachine (for example taken from the compressor part), and used to cool the rotor discs 21, 31, and the annular body. 11 of movable sealing ring 1. In this respect, in one embodiment, the annular body 11 comprises a drain orifice 114 configured so that, in operation, the ventilation air can be evacuated towards the vein of flow 6. As visible in FIGS. 3 and 4, in one embodiment, the drain orifice 114 is oriented upstream of a cavity upstream of the flow stream 6 of the turbomachine, in order to s' oppose the penetration of air towards the annular body 11.

With reference to FIGS. 4 and 5, the movable sealing ring 1 also comprises ventilation lunules 120 formed in the ring flange 12. In operation, the ventilation lunules 120 make it possible to circulate the ventilation air from a rotor cavity 9, where it has been routed, as far as the downstream ventilation cavity 8, through the fixing means 4. From there, the fresh air circulates through the disc 31 of the second rotor 3, to finally supply an adjacent cavity (not shown), then be evacuated to the flow vein 6 via an adjacent drain orifice (not shown).

As visible in FIGS. 3 to 5, in one embodiment, the movable sealing ring 1 comprises an upstream ferrule 112 configured to come to bear against the first disc 21, and a downstream ferrule 113 configured to come into abutment the second disc 31. The upstream ferrule 112 and the downstream ferrule 113 of movable sealing ring 1 can then define, respectively with the downstream ferrule 23 of the first rotor 2 and the upstream ferrule 33 of the second rotor 3, the ventilation cavities 7, 8 previously described. In addition, with reference to FIGS. 3 to 5, the emptying orifice 114 previously described can, in one embodiment, be made at the level of the upstream ferrule 112 of movable sealing ring 1. Alternatively, the orifice drain 114 can also be performed at the level of the downstream ferrule 113 of movable sealing ring 1.

In a preferred embodiment, as visible in FIGS. 3 to 5, the annular body 11 comprises sealing wipers 110 which extend radially outwards relative to the ring flange 12. In operation, these sealing wipers 110 cooperate with the internal annular surface of the fixed vane 50 opposite the movable sealing ring 1, and thus ensure sealing between a successive upstream cavity and a downstream cavity of the flow stream 6 of the turbomachine.

Geometry of the mobile sealing ring 1

The geometry of the movable sealing ring 1 will now be described in more detail.

The movable sealing ring 1, and in particular the annular body 11 and the ring flange 12, have (s) a symmetry of revolution about a longitudinal axis. When the movable sealing ring 1 is disposed within a rotating part of a turbomachine, for example such as that described above, this longitudinal axis coincides with the longitudinal axis XX of the turbomachine, as visible in FIGS. 3 to 5.

As can be seen in these figures, the ring flange 12 has a radially internal end E from which extends a radially internal end portion 121 of the ring flange 12. The radially internal end portion 121 is configured to be fixed on the first fixing flange 22 and the second fixing flange 32, at the level of the fixing means 4. It is also at this first portion 121 that the ventilation rings 120 are formed. The end radially internal E is represented by a point in FIGS. 3 to 5. The radially internal end E is annular and centered on the longitudinal axis XX, and delimits the internal radial portion of the movable sealing ring 1. Furthermore , the ring flange 12 comprises a radially external end portion 13 which connects the ring flange 12 to the annular body 11, as visible in FIG. 4.

The movable sealing ring 1 also has an axial plane P1 comprising the longitudinal axis XX and a radial plane P2 normal to the longitudinal axis XX, and passing through the fixing means 4. These planes P1, P2 provide two-dimensional sections of the movable sealing ring 1. In this regard, FIGS. 3 to 5 illustrate different embodiments of the movable sealing ring 1 along a section of the axial plane P1.

In one embodiment, as illustrated in FIG. 4, the radially external end portion 13 of the ring flange 12, at the intersection between the ring flange 12 and the annular body 11, present in the plane axial P1, a thickness E0 greater than the thickness E1, E2, E3 of the other portions 121, 122, 123 of the ring flange 12. The thickness of a portion E0, E1, E2, E3 of the flange d 'ring means the distance separating two opposite surfaces from the portion of the ring flange 12 taken in the axial plane P1. In this way, the mechanical resistance of the movable sealing ring 1 is reinforced, so as to limit the effects of centrifugal forces during operation.

As shown in FIGS. 3 and 5, the movable sealing ring 1 is such that the ring flange 12 comprises at least one convex and / or concave portion 122, 123, 124, which extends between the portion d radially external end 13 and the radially internal end portion 121 of the ring flange 12.

With reference to the figures, the concave and / or convex portion 122, 123, 124 will now be described in more detail.

As can be seen in these figures, a fictitious point of intersection P can be defined as a point belonging to the axial plane P1, and which is located at the intersection between the annular body 11 and the radial plane P2. It should be noted that, since the mobile sealing ring 1 is of revolution around the longitudinal axis X-X, a plurality of fictitious points P can thus be defined. Indeed, the geometrical location of the intersection between the axial plane P1, the radial plane P2, and the annular body 11, is a pair of symmetrical segments with respect to the center C of the movable sealing ring 1, c ' that is to say with respect to the intersection between the radial plane P2 and the longitudinal axis XX. The fictitious point of intersection P is chosen from all the points of these two segments, as visible in FIGS. 3 and 5. Advantageously, as visible in FIGS. 3 to 5, the ventilation glasses 120 extend substantially according to the radial plane P2, close to the radially internal end E of the ring flange 12

Once this choice of intersection point P has been made, a segment S connecting the fictitious intersection point P and the radially internal end E can also be defined. Such a segment S belongs to the axial plane P1. In this case, the length of this segment S represents the smallest distance between the annular body 11 and the radially internal end E of the ring flange 12.

Furthermore, the ring flange 12 has a curvilinear length L in the axial plane P1, between the point of intersection P previously defined, and the radially internal end E of ring flange 12. Taking into account the symmetry of revolution of the movable sealing ring 1, it is understood that the radially internal end E considered for determining the curvilinear length L is, as visible in FIGS. 3 to 5, the point included in the axial plane P1 which is closest to the point of intersection P, and not its symmetrical with respect to the center C of the movable sealing ring 1. In this case, this curvilinear length L of ring flange 12 means the length along the arc formed by the ring flange profile 12 in the axial plane P1, between the point of intersection P previously defined and the radially internal end E. As can be seen in FIGS. 3 to 5, it is the arc formed by such a profile which has a convex and / or concave geometry. The convexity and / or concavity of the profile are defined relative to the longitudinal axis X-X of the turbomachine, in the direction of flow of the gas flow through the turbomachine. As shown in Figures 3 to 5, a profile having a convex geometry 123 is curved upstream, while a profile having a concave geometry 122, 124 is curved downstream. Given the symmetry of revolution of the mobile sealing ring 1, and more particularly of the ring flange 12, this curvilinear length L is substantially the same in any section of the mobile sealing ring 1 according to an axial plane P1 comprising the longitudinal axis XX.

Thus, the concave and / or convex portion 122, 123, 124 of the ring flange 12 is such that said ring flange 12 has a curvilinear length L in the axial plane P1, between the point of intersection P and its radially internal end E, which is greater than the length of the segment S in said axial plane P1 connecting said point of intersection P and said radially internal end E. In this way, in operation, when the movable sealing ring 1 is fixed to a rotating part of a turbomachine, the thermal gradient which is established between the annular body 11, subjected to the flow of hot air, and the radially internal end E of the ring flange 12, immersed in a cavity 9 of cold air, is distributed over the entire length of the ring flange 12. The portion of ring flange 12 fixed in the bolted connection 4 is then substantially less hot than if the curvilinear length L between point of intersection P and radially internal end E had been substantially equal to the length of the segment S connecting said point of intersection P to said radially internal end E. Thus, in operation, the thermal expansion of the ring flange 12 at the level of the fixing means 4 is limited, which reduces the creep of the movable sealing ring 1, and the opening of the fixing flanges 22, 32 under the effect of centrifugal force.

In one embodiment, the curvilinear length L is greater than 1.5 times the length of the segment, and is up to 4 times the length of the segment. An excessively long curvilinear length L could indeed lead to mechanical embrittlement of the ring flange 12, and / or an excessive increase in weight of the movable sealing ring 1.

In a first embodiment, illustrated in FIGS. 4 and 5, the convex and / or concave portion 122, 123, 124 of the ring flange 12 comprises:

a first portion 122 of curved shape, a second portion 123 of curved shape, a curvature of the first portion 122 being opposite to a curvature of the second portion 123.

As shown in the figures, the combination of the curved shapes of opposite curvatures of the first portion 122 and the second portion 123 gives the ring flange 12 an elbow-like appearance, or a "C" shape. It should be noted that, in these figures, the first curvature has a concavity oriented substantially upstream, and the second curvature has a concavity oriented substantially downstream, which are indeed two opposite directions. This is not, however, limiting, since the first curvature could have a concavity oriented substantially downstream, and the second curvature would then have a concavity oriented substantially upstream. In any event, this configuration makes it possible to lengthen the curvilinear length L in the axial plane P1, between the point of intersection P and the radially internal end E of ring flange 12, in order to limit heating of the portion radially inner end 121 of ring flange

12.

Thanks to this form of elbow, in an embodiment where ventilation tubes 120 are formed in the ring flange 12, the fresh air can, in operation, be ejected in the direction of the annular body 11, for example at the level sealing wipers 110, as visible in FIGS. 4 and 5. This causes the annular body 11 to cool, and contributes to limiting the heating within the movable sealing ring 1.

In a second embodiment, as illustrated in FIG. 3, the convex and / or concave portion 122, 123, 124 of the ring flange 12 further comprises a third portion 124, also of curved shape, whose curvature has a concavity oriented substantially in the same direction as the concavity of the curvature of the first portion 122. This combination of curved shapes of opposite curvatures thus gives the ring flange 12 the appearance of a bellows.

The number and the shape of the curved portions of the ring flange 12 can vary according to the particular configurations of the mobile sealing ring 1, as a function of parameters such as the targeted cooling, the overall weight of the mobile ring d seal 1, or its mechanical stability. In any event, the ring flange 12 comprises at least two successive curved portions 122, 123, of substantially opposite curvatures, in order to ensure that the curvilinear length L in the axial plane P1, between the point of intersection P and the radially internal end E of ring flange 12, is greater than the length of the segment S in said axial plane P1 connecting said point of intersection P and said radially internal end E.

Rotating part set

With reference to FIGS. 3 to 5, a set of rotating parts of a turbomachine, such as that previously described, comprises:

a first rotor 2 comprising a first disc 21 and a first fixing flange 22, a second rotor 3 comprising a second disc 31 and a second fixing flange 32, a means 4 for fixing the first fixing flange 22 on the second flange fixing 32, and a movable sealing ring 1 according to one of the embodiments previously described, the annular body 11 of the movable sealing ring 1 extending between the first disc 21 and the second disc 31, and the ring flange 12 being fixed on the first fixing flange 22 and the second fixing flange 31 at the level of the fixing means 4.

In operation, the flange opening phenomenon 12, 22, 32 is therefore limited in a turbomachine comprising such an assembly. Indeed, the elongation of the curvilinear length L of the ring flange 12 of the movable sealing ring 1 makes it possible to distribute over a greater length the thermal gradient which is established within the movable ring d seal 1 subject to hot air flow.

Claims (10)

1. Movable sealing ring (1) for a rotating part of a turbomachine, said rotating part comprising: - a first rotor (2) comprising a first disc (21) and a first fixing flange (22), - a second rotor (3) comprising a second disc (31) and a second fixing flange (32), - a means of fixing (4) of the first fixing flange (22) on the second fixing flange (32), the movable sealing ring (1) comprising: - an annular body (11) having a symmetry of revolution about a longitudinal axis (X-X), said annular body (11) being configured to extend between the first disc (21) and the second disc (31), - a ring flange (12) extending radially from the annular body (11), and configured to be fixed on the first fixing flange (22) and / or on the second fixing flange (32), the flange d ring (12) having a radially internal end (E) from which extends a radially internal end portion (121) of the ring flange (12), the ring flange (12) comprising a radially outer end portion (13) which connects the ring flange (12) to the annular body (11), the movable sealing ring (1) being characterized in that the ring flange (12) comprises at least one convex and / or concave portion (122, 123, 124) which extends between the radially outer end portion (13) of the ring flange (12) and the radially inner end portion (121 ) of the ring flange (12). 2. movable sealing ring (1) according to claim 1, in which the convex and / or concave portion (122, 123, 124) of the ring flange (12) comprises: - a first portion (122) of curved shape, - A second portion (123) of curved shape, a curvature of the first portion (122) being opposite to a curvature of the second portion (123). 3. movable sealing ring (1) according to one of claims 1 or 2, further having: - an axial plane (P1) comprising the longitudinal axis (X-X), - a radial plane (P2) normal to the longitudinal axis (X-X), and passing through the fixing means (4), and - a fictitious point of intersection (P) being defined as a point belonging to the axial plane (P1), and which is located at the intersection between the annular body (11) and the radial plane (P2), the flange ring (12) having a curvilinear length (L) in the axial plane (P1), between the point of intersection (P) and its radially internal end (E), which is greater than a length of a segment ( S) in said axial plane (P1) connecting said point of intersection (P) and said radially internal end (E). 4. movable sealing ring (1) according to claim 3, in which the curvilinear length (L) is greater than 1.5 times the length of the segment (S), and is up to 4 times the length of the segment ( S). 5. movable sealing ring (1) according to one of claims 1 to 4, wherein the annular body (11) comprises sealing wipers (110) extending radially outward relative to the flange ring (12). 6. movable sealing ring (1) according to one of claims 3 to 5, wherein the radially outer end portion (13) of the ring flange (12) has, in the axial plane (P1) , a thickness (E0) greater than the thickness (E1, E2, E3) of the other portions (121, 122, 123) of the ring flange (12). 7. movable sealing ring (1) according to one of claims 1 to 6 wherein ventilation rings (120) are formed in the ring flange (12). 8. movable sealing ring (1) according to one of claims 1 to 7, wherein the annular body (11) comprises a drain opening (114). 9. Rotating part assembly of a turbomachine, said assembly comprising: - a first rotor (2) comprising a first disc (21) and a first 5 mounting flange (22), - a second rotor (3) comprising a second disc (31) and a second fixing flange (32), a means for fixing (4) the first fixing flange (22) to the second fixing flange (32), and 10 - a movable sealing ring (1) according to one of claims 1 to 8, the annular body (11) of the movable sealing ring (1) extending between the first disc (21) and the second disc (31), and the ring flange (12) being fixed on the first fixing flange (22) and the second fixing flange (32) at the level of the fixing means (4). 10. Turbomachine comprising an assembly according to claim 9.