Assembly for a turbine engine

Abstract

The invention relates to an assembly for a turbine engine comprising: a first, ceramic component comprising an annular wall (44); a second, metal component arranged upstream of the first component; and a connecting flange arranged longitudinally between the first component and the second component, the connecting flange comprising an annular part (47) which is attached to the second component and connecting tabs (50) extending longitudinally downstream from the annular part (47). A plurality of sealing members (60) are distributed circumferentially so as to be adjacent to one another, each sealing member (60) closing, for example in a sealed manner, a space (51) circumferentially delimited between a first connecting tab (50) and a second circumferentially consecutive connecting tab (50), and each sealing member (60) comprising a sealing plate (70) that ensures aerodynamic surface continuity with the annular part (47) and / or the annular wall (44). A turbine engine comprising this assembly is also disclosed.

Description

[0001] DESCRIPTION

[0002] TITLE: Turbomachine Assembly

[0003] The present invention relates to an exhaust assembly for a turbomachine. This description also relates to a turbomachine comprising such an assembly.

[0004] A longitudinally mounted, turbofan-type turbomachine consists of a series of components arranged from upstream to downstream in the direction of gas flow within the turbomachine: fan, low-pressure compressor, high-pressure compressor, combustion chamber, high-pressure turbine, low-pressure turbine, and exhaust nozzle. The compressors are connected to their respective turbines by longitudinal shafts. The incoming airflow is divided into primary and secondary flows. An exhaust casing is located at the outlet of the low-pressure turbine.

[0005] The exhaust nozzle includes an exhaust assembly to optimize the flow of hot gases from the turbine.

[0006] The exhaust assembly may include a ceramic element, such as an ejection cone, connected to the exhaust housing by a metal flange with flexible connecting tabs to compensate for differences in material expansion. Sealing the gaps between the connecting tabs is crucial to prevent hot gas leaks and maintain turbomachine performance.

[0007] Application FR3136516 proposes a turbomachine assembly comprising an ejection cone, an exhaust housing, a longitudinally oriented connecting flange between the exhaust housing and the ejection cone, and a plurality of sealing elements. Each sealing element hermetically seals a circumferentially defined gap between a first and a second circumferentially consecutive connecting lug, and a longitudinally defined gap between the annular portion of the connecting flange and the annular wall of the ejection cone. However, the solution proposed in application FR3136516 has a geometry that disrupts the fluid flow and requires a relatively complex attachment method.

[0008] It is therefore desirable to find a sealing solution that adds minimal weight to the exhaust assembly, exhibits thermoelastic flexibility compatible with potential thermomechanical deformations of the exhaust assembly, and is, on the one hand, easy to connect and, on the other hand, offers a geometry that minimizes disturbance to the fluid flow. To this end, the invention relates to an assembly for a longitudinally mounted turbomachine comprising:

[0009] -a first ceramic component comprising an annular wall,

[0010] -a second metallic component arranged upstream of the first component, and

[0011] - a connecting flange arranged longitudinally between the first component and the second component, the connecting flange comprising an annular part which is fixed to the second component and connecting lugs extending longitudinally downstream from the annular part, the connecting lugs being distributed circumferentially around the longitudinal axis, each connecting lug being connected to the annular wall of the first component,

[0012] - a plurality of sealing elements distributed circumferentially adjacent to each other around the longitudinal axis, one or more sealing elements among the plurality of sealing elements closing at least a circumferentially delimited space between a first connecting lug and a second circumferentially consecutive connecting lug, each sealing element comprising a sealing plate extending longitudinally at least from the annular part to the annular wall and ensuring with the annular part and / or the annular wall an aerodynamic surface continuity.

[0013] By "upstream", we mean upstream longitudinally and / or in relation to the direction of gas flow within the turbomachine.

[0014] Advantageously, the sealing plate, which ensures a continuous aerodynamic surface with the annular section and / or the annular wall, minimizes disturbances in the airflow around the aircraft. Airflow resistance is reduced, resulting in lower fuel consumption and improved aerodynamic performance.

[0015] In addition, the turbomachine assembly may have one or more of the following characteristics taken alone or in combination.

[0016] According to one characteristic, at least one sealing element, preferably each sealing element, comprises a downstream tab extending longitudinally downstream from the sealing plate, the downstream tab bearing in the radial direction against the annular wall of the first component.

[0017] Advantageously, the downstream tab can reduce leaks of air or hot gases between the first component and the second component.

[0018] According to one characteristic, each sealing element has an upstream end that extends longitudinally upstream from the sealing plate, the upstream end being applied radially to the annular portion of the connecting flange. Advantageously, the upstream end can reduce leakage of air or hot gases between the first and second components.

[0019] According to one characteristic, an intermediate zone is formed between two circumferentially adjacent and consecutive sealing elements, each intermediate zone being radially aligned with a location of a connecting lug.

[0020] According to one characteristic, two circumferentially adjacent and consecutive sealing elements are, at least partially, in contact with the connecting tab at the intermediate zone and jointly exert pressure on said connecting tab in the radial direction.

[0021] Advantageously, the pressure exerted by the two circumferentially adjacent and consecutive sealing elements 60 ensures a seal between the free spaces formed circumferentially between each pair of circumferentially adjacent legs.

[0022] According to one characteristic, a joint is arranged radially between the intermediate zone and the connecting tab with which said intermediate zone is radially aligned.

[0023] Advantageously, the seal improves the sealing between the free spaces formed circumferentially between each pair of circumferentially adjacent legs.

[0024] According to one characteristic, the sealing plate has an external face and an internal face opposite the external face, and each sealing member includes a lateral tab extending laterally from the sealing plate and configured to bear radially against the internal face of the sealing plate of the circumferentially consecutive sealing member.

[0025] Advantageously, the lateral tab which bears radially on the inner face of the sealing plate of the circumferentially consecutive sealing element makes it possible to mask the free space and improve the sealing.

[0026] According to one characteristic, the upstream ends of the sealing elements are connected to each other by a continuous ring.

[0027] Advantageously, by connecting the upstream ends of the sealing elements together with a continuous ring, a more effective airtight barrier against fluid or gas leaks is created.

[0028] According to one characteristic, the upstream ends of the sealing elements are fixed to the annular part of the connecting flange and the downstream tabs of the sealing elements slide on the annular wall.

[0029] The invention further relates to a turbomachine comprising the turbomachine assembly described above. Brief description of the figures

[0030] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached figures, in which:

[0031] [Fig.1] is a partial schematic half-view in cross-section of a prior art longitudinal axis turbomachine in a longitudinal cross-section plane;

[0032] [Fig.2] is a partial schematic perspective view of an exhaust assembly of the turbomachine in Figure 1;

[0033] [Fig.3] is a larger scale schematic perspective view of an upstream end portion of the exhaust assembly in Figure 2;

[0034] [Fig.4a] is a schematic partial detail perspective view of an exhaust assembly according to the present description;

[0035] [Fig.4b] is a larger scale schematic perspective view of an upstream end portion of the exhaust assembly in Figure 4a;

[0036] [Fig.5a] is a schematic perspective view of an upstream end portion of the exhaust assembly in which the connecting flange partially forms an aerodynamic duct;

[0037] [Fig.5b] is a schematic perspective view of an upstream end portion of the exhaust assembly in which the sealing element includes at its upstream end a radial return;

[0038] [Fig.5c] is a schematic perspective view of an upstream end portion of the exhaust assembly in which the sealing element extends from a first component to a second component of the turbomachine assembly according to the invention;

[0039] [Fig. 6] is a schematic perspective view of an upstream end portion of the exhaust assembly in which a sealing element is welded to an annular part of the connecting flange;

[0040] [Fig.7a] is a schematic partial detail perspective view of an exhaust assembly showing the sealing components;

[0041] [Fig.7b] is a schematic partial detail perspective view of an exhaust assembly with a greater number of sealing elements than that shown in Figure 7a;

[0042] [Fig.8] is a schematic cross-sectional view of the annular part of the connecting flange according to a first embodiment showing a section of the sealing elements and connecting lugs;

[0043] [Fig.9] is a schematic cross-sectional view of the annular part of the connecting flange according to a second embodiment showing a section of the sealing elements and connecting lugs; [Fig.10] is a schematic cross-sectional view of the annular part of the connecting flange according to a first variant of a third embodiment showing a section of the sealing elements and connecting lugs;

[0044] [Fig.11] is a schematic cross-sectional view of the annular part of the connecting flange according to a second variant of the third embodiment of Figure 10 showing a section of the sealing elements and connecting lugs;

[0045] [Fig.12] is a schematic cross-sectional view of the annular part of the connecting flange according to a third variant of the third embodiment of Figure 10 showing a section of the sealing elements and connecting lugs;

[0046] [Fig.13a] is a schematic perspective view of an upstream end portion of the exhaust assembly in which the upstream end of a sealing element is fixed to the annular part of the connecting flange;

[0047] [Fig.13b] ​​is a schematic perspective view of two sealing elements of figure 9;

[0048] [Fig.14] is a larger scale schematic perspective view of an upstream end portion of the exhaust assembly in which the upstream end of a sealing element is fixed to the annular part of the connecting flange according to a first embodiment;

[0049] [Fig.15] is a schematic perspective view of an upstream end portion of the exhaust assembly in which the upstream end of a sealing element is fixed to the annular part of the connecting flange according to a second embodiment.

[0050] In these figures which are not drawn to scale, the same numerical references designate the same elements.

[0051] Detailed description

[0052] Figure 1 shows an example of a turbomachine with a longitudinal axis X in a longitudinal section plane. As can be seen in Figure 1, the turbomachine 10 of the longitudinal axis turbofan type comprises, from upstream to downstream in the direction of gas flow within the turbomachine 10, a fan 12, a low-pressure compressor 14a, a high-pressure compressor 14b, a combustion chamber 16, a high-pressure turbine 18a, a low-pressure turbine 18b and an exhaust nozzle 20.

[0053] The high-pressure compressor 14b and the low-pressure compressor 14a are respectively connected to a high-pressure turbine 18a and a low-pressure turbine 18b by a respective shaft extending along the longitudinal axis X. In the following, orientation qualifiers such as "longitudinal", "radial" and "circumferential" are defined with reference to the longitudinal axis X. The airflow entering the turbomachine is divided, downstream of the fan 12, into a primary annular airflow passing through an annular stream 22a called the primary, and into a secondary annular airflow, passing through an annular stream 22b called the secondary which surrounds the primary annular air stream 22a. The low-pressure compressor 14a and the high-pressure compressor 14b, the combustion chamber 16, and the high-pressure turbine 18a and the low-pressure turbine 18b, are located for the upstream working parts in the primary annular vein 22a.

[0054] An exhaust casing 30 is located directly at the outlet of the low-pressure turbine 28b. The exhaust casing 30 comprises a radially internal ferrule 32 and a radially external ferrule 34. An annular space formed between the internal and external ferrules forms part of the primary stream 22a at the outlet of the low-pressure turbine 18b. The internal ferrule 32 of the exhaust casing can be metallic, for example, made of titanium alloy or Inconel®-type alloy.

[0055] The exhaust nozzle 20, or ejection nozzle, of the turbomachine 10 includes an exhaust assembly designed to optimize the flow of hot gases from the turbine. This assembly may also serve to absorb at least some of the noise generated by the interaction of these hot gases with the ambient air and with the flow of cold air from the fan 12.

[0056] This escapement assembly may include a first ceramic component 40 such as an ejection cone which includes an upstream part 40a, substantially axisymmetric in shape around the longitudinal axis X, and a downstream part 40b substantially conical in shape along the longitudinal axis X. The upstream part 40a includes an upstream annular wall 44.

[0057] The upstream annular wall 44 is connected to the downstream end of the internal ferrule 32 of the exhaust housing 30 via a connecting flange 46.

[0058] The connecting flange 46 is metallic, for example, made of titanium alloy or Inconel®-type alloy. The connecting flange 46 has an annular portion 47 around the longitudinal axis X, from which flexible connecting tabs 50 extend downstream, evenly distributed around the circumference. The annular wall 44 of the first ceramic component 40 partially surrounds the connecting tabs 50 and is connected to each of the connecting tabs 50. Such flexible connecting tabs 50 compensate for the differential expansion phenomena occurring between the inner shell 32 of the exhaust housing 30 and the first component 40, these two elements being made of materials having different coefficients of thermal expansion.

[0059] In order not to reduce the performance of the turbomachine, it is necessary to seal the free spaces 51 formed circumferentially between each pair of circumferentially adjacent connecting lugs 50 and longitudinally between the downstream annular part 47 of the connecting flange 46 and the upstream annular wall 44 of the first component 40 to prevent leakage of the flow of hot gases radially inwards.

[0060] The invention relates to an exhaust assembly for a turbomachine, hereinafter referred to as the turbomachine assembly, with longitudinal axis X. The assembly can find application for a nozzle, or a mixer in a turbomachine.

[0061] As mentioned above, the turbomachine assembly includes the first ceramic component 40, such as the ejection cone. The first component 40 comprises the annular wall 44, as shown in Figure 2. The first component 40 can be made of oxide-oxide or silicon carbide reinforced with silicon carbide fibers.

[0062] The turbomachine assembly also includes a second metallic component 30 such as an exhaust housing, which is arranged upstream of the first component 40. The second component 30 can be made of steel or nickel alloy.

[0063] For example, the second component 30 may be made of steel and have a linear coefficient of thermal expansion of approximately 12 x 10⁻⁶ m / m / °C, while the first component 44 may be made of ceramic and have a linear coefficient of thermal expansion of approximately 5 x 10⁻⁶ m / m / °C to 7 x 10⁻⁶ m / m / °C. During turbomachine operation, the relative variation in the diameters of the first and second components can reach approximately 4 x 10⁻³ m / m to 5 x 10⁻³ m / m. If the first component 40 and the second component 30 are fixed together without any intermediate element between them, considerable mechanical stresses can be generated, which can impair the operation of the turbomachine. It is therefore advisable to use a suitable fastening method between the first component 40 and the second component 30.

[0064] For this purpose, the connecting flange 46 is arranged longitudinally between the first component 40 and the second component 30, the second component 30 being, for example, an exhaust housing, also called an engine body. By "arranged longitudinally," it is meant that the connecting flange 46 is positioned between the first component 40 and the second component 30 along the longitudinal axis X shown in Figures 1 and 2.

[0065] The connecting flange 46 includes an annular part 47 which is fixed to the second component 30 and connecting lugs 50 which extend longitudinally downstream from the annular part 47.

[0066] The connecting lugs 50 are distributed circumferentially around the longitudinal axis X as shown in Figure 2 and each connecting lug 50 is connected to the annular wall 44 of the first component 40. By "distributed circumferentially around the axis X", it is meant that the connecting lugs 50 are distributed in a circular manner around the axis X, for example along the circumference of the annular part 47 of Figure 2. By way of guide, a longitudinal dimension of the flange 46 along the axis X can be between 40 mm and 200 mm, preferably 100 mm, with a variation of plus or minus 25 mm.

[0067] The flange 46 can preferably include between 16 and 100 connecting lugs depending on the diameter of the flange 46 and the design choices.

[0068] A transverse dimension of a 50 connecting leg can be between 20 and 30 mm, and a maximum distance separating two circumferentially consecutive legs can be between 15 and 100 mm.

[0069] The connecting lugs 50 can have a longitudinal dimension along the X-axis of approximately 100 mm and can withstand a longitudinal elongation of approximately 1 mm when the turbomachine is in operation. The longitudinal distance between the first component 40 and the second component 30 can then vary by approximately 1 mm.

[0070] The turbomachine assembly also includes a plurality of sealing elements 60 distributed circumferentially adjacent to one another around the longitudinal axis X. By "circumferentially adjacent" sealing elements 60, it is understood that the sealing elements 60 are distributed in a circular fashion around the axis X, for example along the circumference of the annular portion 47, and arranged along this circumference side by side or close to one another. For example, two circumferentially adjacent sealing elements 60 may be in contact with each other or, alternatively, separated by a gap j. The gap j is shown, for example, in Figure 8. The value of the gap j may be greater than or equal to one micrometer.

[0071] The value of the clearance j can be determined as follows: it is assumed that the diameter of the flange 46 can vary by D mm depending on the operating temperature of the assembly, for example, by approximately 3 mm. Over a complete circumference of 360°, a total variation of D mm x TT = 3 mm x TT = 9.42 mm (rounded to 9 mm for simplification) can be calculated. For example, if the assembly comprises 24 sealing elements 60, each individual clearance is 9 mm / 24 = 0.375 mm. Alternatively, if the flange 46 comprises 12 sealing elements, each individual clearance is 9 mm / 12 = 0.75 mm.

[0072] Thus, to calculate the maximum individual clearance j separating two circumferentially consecutive sealing elements 60 when the flange includes n sealing elements 60, and D denotes the variation in millimeters of the diameter of the flange 46, the variation in diameter D is multiplied by TT, and the result obtained is divided by the number n of sealing elements 60.

[0073] One or more sealing elements 60 from among the plurality of sealing elements 60 close, for example, in a hermetic manner, at least one circumferentially defined space 51 between a first connecting tab 50 and a second circumferentially consecutive connecting tab 50. For example, a single sealing element 60 can hermetically close two circumferentially consecutive spaces 51. A second connecting tab circumferentially consecutive to the first connecting tab designates a connecting tab 50 that immediately follows the first connecting tab 50 in the direction of the circumference of the annular portion 47, as can be seen in Figure 2.

[0074] Each sealing element 60 can have a polygonal shape, for example a rectangular shape, and can have a longitudinal dimension along the X axis less than or equal to the longitudinal dimension of the flange 46 along the X axis which can be between 40 mm and 150 mm, preferably 100 mm with a variation of plus or minus 25 mm, and a transverse dimension, orthogonal to the longitudinal dimension, between 30 and 100 mm.

[0075] Each sealing element 60 can have an arched configuration and, for example, an arc length of between 30 and 100 mm. Longer arc lengths can be considered if a sealing element 60 closes two or more spaces 51.

[0076] Each sealing element 60 comprises a sealing plate 70, as shown, for example, in Figures 3 to 6, extending longitudinally from the annular portion 47 to the annular wall 44. The sealing plate 70 may have a polygonal shape configured to seal the circumferentially defined space 51 between a first connecting tab 50 and a second circumferentially consecutive connecting tab 50. The sealing plate 70 may, for example, have a shape complementary to the shape of the space 51, for example, a rectangular shape. The sealing plate 70 may have an external face 71 and an internal face 80 opposite the external face 71, as shown in Figure 3.

[0077] Each sealing element 60 may have a thickness less than or equal to 1.5 mm, preferably less than 1 mm, and for example less than or equal to 0.6 mm. The sealing element 60 is therefore lightweight and resistant to the differential pressure forces exerted on either side of said sealing element 60 by the annular part 47 and the annular wall 44.

[0078] The sealing plate 70 can be made of a metallic material. Preferably, the sealing plate 70 comprises a metal alloy. This is the case, for example, in the example in Figure 6 where the sealing plate is attached to the flange 46 by welding.

[0079] The sealing plate 70 can be forged, machined, cast, or produced by additive manufacturing. Alternatively, the sealing plate 70 can be made of ceramic, for example, long-fiber or short-fiber laminated ceramic, injected or compressed and then sintered. Using ceramic reduces the weight of the components. However, ceramic may be less economical, and some configurations, for example, those shown in Figures 10, 11, and 12, may be difficult to achieve. The sealing elements 60 can be free to move from each other within the portion of the aerodynamic duct containing the connecting tabs 50.

[0080] In other words, the sealing elements 60 and / or the connecting tabs 50 can be connected to each other at their upstream end 79, for example by the annular part 47, and can not be connected to each other at their downstream end 78, for example at the annular wall 44. The sealing elements 60 can then stretch or retract at the annular wall 44.

[0081] Alternatively, the sealing elements 60 and / or the connecting tabs 50 can be connected to each other by the annular wall 44 at their downstream end 78 and may not be connected to each other at their upstream end 79, for example at the annular part 47. The sealing elements 60 and / or the connecting tabs 50 can then stretch or retract at the annular part 47.

[0082] The sealing elements 60 and / or connecting tabs 50 are flexible and can flex radially inwards or outwards from the flange 46. The movement of each sealing element 60 and / or each connecting tab 50 is independent of the movement of the other sealing elements 60 and / or the other connecting tabs 50.

[0083] In the examples shown in figures 5, 6 and 7, the sealing elements 60 are joined together via the annular part 47, the annular part 47 being connected to the flange 46 and / or to the second component 30.

[0084] Each sealing element 60 can be directly attached to the annular part 47. Alternatively, each sealing element 60 can be directly attached to the second component 30.

[0085] In the examples of Figures 13 to 15, the sealing elements 60 and / or the connecting lugs 50 are fixed to the annular wall 44; and the upstream ends of the connecting lugs 50 and / or the sealing elements 60 bear against the annular part 47. The upstream ends of the connecting lugs 50 and / or the sealing elements 60 can move in a radial direction as a function of a variation in diameter between the second component 30 and the annular wall 44, a variation in diameter which occurs due to the operating temperature of the turbomachine.

[0086] The sealing plate 70, together with the annular portion 47 and / or the annular wall 44, ensures a continuous aerodynamic surface. In other words, the sealing plate 70, together with the annular portion 47 or the second component 30 on the one hand, and the annular wall 44 on the other, forms a flush assembly. In other words, the sealing plate 70, together with the annular portion 47 or the second component 30 and the annular wall 44, creates an aerodynamic surface without any offset. In other words, and with reference to Figure 3, the sealing plate 70 and the annular portion 47 are aligned at their interface so that there is no offset or disparity perceptible to the naked eye between them.

[0087] Similarly, with reference to Figure 3, the sealing plate 70 and the annular wall 44 are aligned at their interface 1000 so that there is no offset or disparity perceptible to the naked eye between them.

[0088] The flush assembly between the annular part 47 and / or the sealing plate 70 and the flush assembly between the annular wall 44 and / or the sealing plate 70 ensures continuity of the aerodynamic surface.

[0089] For all the examples shown in the figures, the fact that the sealing elements can have a flexing movement in the radial direction makes it possible to ensure the continuity of the aerodynamic line even when the diameter of the annular wall 44 of the first component 40 expands or contracts relative to the aerodynamic line or when the first component 40 deforms (flexing, ovalization) under the effect of a radial flexing of the connecting tabs 50 between the annular part 47 and the first component 40.

[0090] Figure 4a is a schematic partial perspective detail view of a turbomachine assembly as described herein. Figure 4a shows the annular portion 47 of the connecting flange 46 and the annular wall 44, as well as the sealing elements 60 arranged between the annular portion 47 and the annular wall 44.

[0091] Figure 4b is a schematic perspective view of an upstream end portion of the exhaust assembly of Figure 4a. With reference to Figure 4b, each sealing element 60 may have an upstream end 79 extending longitudinally upstream from the sealing plate 70, the upstream end 79 being applied, in the radial direction to the annular portion 47 of the connecting flange 46. It is understood that the radial direction means the direction along a line following a defined radius between the center of the circumference of the annular portion 47, which is intersected by the X-axis, and a point on the circumference of the annular portion 47. In the embodiment of Figures 4a and 4b, each sealing element 60 extends from the annular wall 44 and at most to an interface So between the second component 30 and the annular portion 47.In other words, the upstream end 79 of each sealing element 60 extends to a contact surface So between the connecting flange 46 and the second component 30.

[0092] At least one sealing element 60, preferably each sealing element 60, may include, for example at the downstream end of the sealing element 60, a downstream tab 78 extending longitudinally downstream from the sealing plate 70, as can be seen in Figure 4b. The downstream tab 78 does not extend continuously from the sealing plate 70 but rather forms an L-shaped section with the sealing plate 70. The downstream tab 78 may bear radially against the annular wall 44 of the first component 40, for example, radially against a face of the annular wall 44 opposite to the aerodynamic flow.

[0093] The downstream tongue 78 can have a defined thickness so that there is little or no play between said downstream tongue 78 and one or more connecting tab(s) 50 arranged radially above said downstream tongue 78. For example, the play can be between 0 and 0.4 mm, preferably between 0 and 0.2 mm.

[0094] Thus, a radial displacement of the annular wall 44 of the first component 40 which causes a displacement in the same direction of the corresponding connecting lug(s) 50, also causes a radial displacement of a downstream end of the sealing plate 70 and thus maintains the continuity of the aerodynamic surface without offset.

[0095] The downstream tongue 78 can extend over all or part of the inner wall of the annular wall 44. Preferably, the downstream tongue 78 covers the entire circumferential width along which the sealing plate 70 extends the first component 40.

[0096] The downstream tab 78 may comprise a first surface 782, or internal surface, and a second surface 781, or external surface, opposite the first surface 782, as shown in Figure 4b. The term "internal surface" refers to a surface oriented towards the interior of the connecting flange 46 of the turbomachine assembly. The term "external surface" refers to a surface oriented towards an environment external to the described turbomachine assembly.

[0097] Each connecting leg 50 may have an external surface 502 and an internal surface 501 opposite the external surface. The annular wall 44 may also have an internal surface 441 as shown in Figure 4b.

[0098] Referring to Figure 4b, if the clearance between the downstream tab 78 and one or more connecting tabs 50 arranged radially above said downstream tab 78 is zero, the external surface 502 of the connecting tab 50 is in contact with the internal surface 782 of the tab 78 on the one hand, and the external face 781 of the tab 78 is in contact with the internal face 441 of the upstream portion 44 of the first component 40 on the other hand. Thus, the relative sliding between the downstream tab 78, the connecting tab(s) 50 arranged radially above said downstream tab 78, and the annular wall 44 occurs with friction, and the sealing of the turbomachine assembly described is improved.

[0099] The sealing elements 60 may have the same structure. Alternatively, the sealing elements 60 may have different structures. For example, for a sealing assembly applied to an aircraft plug, the sealing elements may have the same structure. Conversely, for an application of the sealing assembly to a nozzle or mixer, the sealing elements 60 may have a different structure because singularities such as variations in shape may appear at the engine interface.

[0100] Figure 5a and Figure 6 show an example of the turbomachine assembly in which the connecting flange 46 partially forms an aerodynamic duct, for example at the annular part 47. In this example, the annular wall 44 is fixed to the connecting flange 46 by a bolted assembly 105. The bolted assembly 105 provides a robust and secure connection between the annular wall 44 and the connecting flange 46 and allows for quick and easy disassembly and reassembly.

[0101] In the example shown in Figure 5a, the annular portion 47 of the flange 46 constitutes the aerodynamic line, and the upstream ends 79 of the sealing elements 60 are housed in a counterbore formed in the annular portion 47. Advantageously, the example in Figure 5a allows for better control of the aerodynamic surface continuity between an exhaust system comprising the flange 46 and the first component 40 and the second component 30, by offering the possibility of adjusting, for example by machining and dimensional control, a diameter of the annular portion 47 of the flange 46 to properly adapt the flange 46 to the diameter of the second component 30, and subsequently by offering the possibility of adjusting the thickness of the sealing elements 60 relative to a depth of the counterbore formed in the annular portion 47. In the example shown in Figure 5a, the sealing elements 60 are fixed to the flange 46 by blind radial or through fasteners 791.

[0102] Figure 6 shows an example of the turbomachine assembly in which the downstream tab 78 bears radially against the annular wall 44 of the first component 40, and the upstream end 79 is welded to the annular part 47. The weld provides a tight and hermetic connection between the upstream end 79 and the annular part 47. The weld also eliminates the discontinuity in the aerodynamic line between the connecting tabs 50 and the annular part 47, and the weld can be adjusted (sanding, grinding, etc.) to reduce or eliminate undulations in the aerodynamic line.

[0103] Alternatively, the sealing elements 60 are fixed directly onto the second component 30 in a counterbore of the aerodynamic line.

[0104] Advantageously, fixing the sealing elements 60 in the counterbore of the second component 30 further improves the offsets at the upstream connection, since there is then only one offset, and it is managed directly at the counterbore between the second component 30 and the sealing element 60. Furthermore, fixing the sealing elements 60 in the counterbore of the second component 30 allows for separate management of aerodynamic continuity and the sealing elements 60, with respect to the connecting flange 46 between the first component 40 and the second component 30. Alternatively, each sealing element 60 includes at its upstream end 79 a radial return 79a as shown in Figure 5b. According to this alternative, the sealing elements 60 are independent of each other. The sealing elements 60 can also be connected to each other by a common ring.

[0105] Advantageously, the radial return 79a can provide radial rigidity to the upstream end 79 of the sealing element 60, which can improve the flushness between the second component 30 and the sealing element 60.

[0106] The common ring may have an L-shaped section including a radial part to be fixed between the flange 46 and the second component 30, and the sealing elements 60 may be connected to the common ring downstream of a cylindrical part of the common ring.

[0107] In the embodiment of figures 4a and 4b, each sealing element 60 extends from the annular wall 44 and at most to the interface So between the second component 30 and the annular part 47.

[0108] In the embodiments of Figures 5a and 6, each sealing element 60 extends from the annular wall 44 to the annular part 47 but without reaching the interface So, thus reducing an offset of the aerodynamic duct, while generating two interfaces of parts on the aerodynamic surface.

[0109] In the embodiment of Figure 5c, each sealing element 60 is fixed to the second component 30 so that the upstream end 79 is upstream of the interface So. Advantageously, the embodiment of Figure 5c improves aerodynamic continuity because aerodynamic continuity is more easily optimized upstream since the offset is the direct difference between the thickness of the sealing elements 60 and the depth of the counterbore.

[0110] In the embodiment of Figure 5b, the radial return 79a advantageously eliminates an asperity on the aerodynamic surface due to the method of fixing the sealing elements 60 to the upstream part, thus improving aerodynamic performance.

[0111] Figure 7b shows an example of a turbomachine assembly comprising an equal number of sealing elements 60 and connecting lugs 50. The radial mobility of the sealing plate 70 or of the sealing elements 60 is directly correlated to the mobility of the connecting lug 50, or of the two connecting lugs 50, which the sealing plate or the sealing element 60 covers.

[0112] Figure 7a shows another example of a turbomachine assembly that includes half as many sealing elements 60 as connecting lugs 50. Advantageously, there is half the clearance between the sealing elements 60 and therefore half the aerodynamic losses due to clearance. On the other hand, the radial movement of the sealing elements 70 must accompany the radial movements of two to three connecting lugs 50, which can generate discontinuities at the junctions between the sealing elements 60.

[0113] In another variant not shown in the figures, the number of sealing elements 60 is greater than the number of connecting lugs 50. For example, the turbomachine assembly may include twice as many sealing elements 60 as connecting lugs 50, for instance, if the number of connecting lugs 50 is reduced and the angular spacing between the connecting lugs 50 is large. The flexibility of the reduced number of sealing elements 60 might not be sufficient to maintain the aerodynamic surface quality.

[0114] With reference to Figures 8 to 12, an intermediate zone 300 can be formed between two circumferentially adjacent and consecutive sealing elements 60. The intermediate zone 300, for example, ensures better sealing between the sealing elements 60 in the free current zone and helps to keep the offsets between sealing elements 60 below a given threshold. Thus, the step, or offset height, or aerodynamic line offset, between two sealing elements 60 can be less than 0.4 mm, preferably less than 0.2 mm, and even more preferably less than 0.1 mm.

[0115] Each intermediate zone 300 can be radially aligned with a location of a connecting tab 50, which allows a connecting tab 50 to be used to help seal the intermediate zone 300 between the sealing members 60, thus enabling lighter designs.

[0116] The intermediate zone 300 can be a clearance, and for example a clearance between one micrometer and one millimeter.

[0117] The clearance compensates for dimensional variations in the sealing elements 60 resulting from manufacturing and / or thermal expansion of said sealing elements 60 related to engine operation. Furthermore, the clearance can reduce friction and mechanical stress, which can contribute to extending the service life of the sealing elements 60 and therefore of the entire turbomachine assembly.

[0118] Figure 8 shows a first embodiment in which two circumferentially adjacent and consecutive sealing elements 60 can be, at least partially, in contact with the connecting tab 50 at the intermediate zone 300 and can jointly exert pressure on said connecting tab 50 in the radial direction. In the example of Figure 8, two sealing elements have a gap between them. In other words, the intermediate zone 300 is formed by a gap.

[0119] Advantageously, the pressure exerted by the two circumferentially adjacent and consecutive sealing elements 60 ensures a seal between the free spaces 51 formed circumferentially between each pair of circumferentially adjacent connecting lugs 50, without requiring an additional part.

[0120] Figure 9 shows a second embodiment in which each sealing element 60 may include a lateral tab 200 extending laterally from the sealing plate 70. "Laterally" means in a direction orthogonal to the longitudinal direction along the X-axis. The lateral tab 200 may bear radially against the inner face 80 of the sealing plate 70 of the circumferentially adjacent sealing element 60, as can be seen in Figure 9. The lateral tab 200 may extend along the entire lateral edge of the sealing element 60, as shown in Figure 13b, for example, or alternatively, the lateral tab 200 may extend partially along the lateral edge of the sealing element 60.In the embodiment of figure 9, the intermediate zone 300 is present but the sealing of the intermediate zone 300 is ensured by the lateral tab 200, the sealing is not ensured by the connecting tab 50. The sealing elements 60 are in contact with each other via the lateral tabs 200.

[0121] Advantageously, the example in Figure 9 allows the movements of the sealing elements 60 to be decoupled from the movements of the connecting tabs 50. Thus, the intermediate zones 300 can be arranged circumferentially independently of the locations of the connecting tabs 50. The sealing of the free spaces 51 is ensured by the sealing elements 60, the lateral tabs ensure the sealing of the gap formed by the intermediate zones 300.

[0122] Figures 10 to 12 show variations of a third embodiment in which a seal 90 is arranged radially between the intermediate zone 300 and the connecting tab 50 with which said intermediate zone 300 is radially aligned. In other words, for each connecting tab 50, said connecting tab 50, the seal 90, and the intermediate zone 300 are arranged on the same line following the radial direction. In Figures 10 to 12, the intermediate zones 300 include a gap between the sealing elements 60.

[0123] Advantageously, the 90 joint improves the sealing between the free spaces 51 formed circumferentially between each pair of circumferentially adjacent 50 legs.

[0124] The seal can be a braided seal, for example a metal braid, as in figures 10 and 11 or alternatively a spring seal as in the example in figure 12.

[0125] The spring seal can be integrated into the sealing element 60, in other words the spring seal can be an integral part of the sealing element 60 or be a separate component of the sealing element 60.

[0126] As can be seen in Figure 10, each connecting tab 50 includes a seal housing 50a. The seal housing 50a can have a shape complementary to the shape of the seal 90 and can retain the seal 90 radially between the intermediate zone 300 and the connecting tab 50 with which said intermediate zone 300 is radially aligned. This allows the seal 90 to be retained in a simple and economical manner.

[0127] In the variant shown in Figure 11, each sealing element 60 has a radially projecting retaining tab 60a on each of its lateral edges. In other words, retaining tabs 60a extend radially from each sealing element 60. The retaining tabs 60a can hold the gasket 90 in the radial direction between the intermediate zone 300 and the connecting tab 50 with which said intermediate zone 300 is radially aligned between the retaining tab 60a of a first sealing element 60 and the retaining tab 60a of a second, circumferentially consecutive sealing element 60. This allows the gasket 90 to be held in place simply and economically.

[0128] In the variant shown in Figure 12, the seal 90 is a spring seal. The spring seal is radially secured by crimping between the intermediate zone 300 and the connecting tab 50. Crimping the spring seal ensures a tight seal and allows for simple and economical installation of the seal 90.

[0129] The upstream ends 79 of the sealing elements 60 can be connected to each other by a continuous ring. "Connected to each other by a continuous ring" means that the upstream end 79 of each sealing element 60 is connected to a circumferential part in the shape of a ring. For example, the sealing elements 60 are attached at their upstream end 79 to a cylinder. Advantageously, attaching the sealing elements 60 to a continuous ring allows the individual sealing elements to be assembled onto a single ring, and then the ring to be installed with the flange 46 and the motor assembly.

[0130] The upstream ends 79 of the sealing elements 60 can be fixed to the annular portion 47 of the connecting flange 46, and the downstream tabs 78 of the sealing elements can slide on the annular wall 44. By "sliding," it is understood that the downstream tabs 78 have at least one degree of translational freedom with the annular wall 44 in the longitudinal direction, along the X-axis, and secondarily in the circumferential direction. Advantageously, when the connecting tabs 50 change length but differently from the sealing elements 60, or when the first component 40 deforms due to bending of one or more connecting tabs 50, the annular wall 44 can slide on the downstream tabs 78 without generating mechanical stress while maintaining a good seal of the free space 51.

[0131] In addition or alternatively, the downstream tabs 78 may include a seal or sealing system, for example such as the seal shown in Figures 10, 11 and 12. The seal may be disposed between the sealing member 60 and the annular wall 44 instead of being disposed between two sealing members 60. The upstream ends 79 of the sealing members 60 may be fixed to the annular part 47 of the connecting flange 46 by means of fixing, for example a bolted assembly or through-fixings with countersunk holes.

[0132] Alternatively, the upstream ends 79 of the sealing elements 60 can be fixed to the annular part 47 of the connecting flange 46 by welding.

[0133] Alternatively, the downstream tabs 78 of the sealing elements 60 can be fixed to the annular wall 44, and the upstream ends 79 can slide relative to the annular portion 47. As can be seen in Figure 13b, the sealing elements 60 have a hole at the downstream tabs 78 for positioning a fastener to connect each of the connecting lugs 50 to the annular portion 44 of the first component 40. A fastener can, for example, be the bolted assembly 105 connecting the connecting lugs 50 to the annular portion 44, or independent fasteners between the downstream tabs 78 and the annular portion 44.

[0134] Figures 13a, 14 and 15 present examples of a turbomachine assembly in which the upstream ends 79 of the sealing elements 60 are fixed to the annular part 47 of the connecting flange 46 so as to be able to slide relative to each other.

[0135] For example, figure 13a presents a first embodiment in which the upstream end 79 rests on a counterbore made in the annular part 47.

[0136] Figure 14 shows a second embodiment in which each sealing element 60 includes a hook 201 extending from the inner face 80 of the sealing plate 70. The hook 201 can radially bear against the face of the annular portion 47 of the mounting flange 46 opposite the aerodynamic face to hold the sealing element 60 stationary relative to the annular portion 47. The hook 201 allows for quick, simple, and flexible assembly when attaching the sealing element 60 to the annular portion 47. The hook 201 can have a shape that provides flexibility to ensure pressure of the sealing element 60 against the annular portion 47 of the flange 46 and can accommodate slight variations in the thickness of said annular portion 47.

[0137] Figure 15 shows a third embodiment in which the annular portion 47 of the connecting flange 46 includes a groove 202 formed in said annular portion 47. The groove 202 can receive the upstream end 79 of the sealing element 60 such that the upstream end 79 engages in the groove 202 to hold the sealing element 60 stationary relative to the annular portion 47. The upstream end 79 may have an upstream tab 79a as shown in Figure 15. The upstream tab 79a can engage in the groove 202. The insertion of the upstream end 79 (or the upstream tab 79a) into the groove 202 can distribute the mechanical stresses over a larger area, thereby reducing local stresses and improving the durability of the connection.

[0138] The sealing elements 60 can be made of a first material having a first coefficient of thermal expansion, and the connecting tabs 50 can be made of a second material having a second coefficient of thermal expansion. The first coefficient of thermal expansion may differ from the second coefficient of thermal expansion by plus or minus 50%. For example, the sealing elements can be made of a material suitable for operation at a temperature at least above 650°C, and preferably above 750°C, such as a metallic or ceramic material. The connecting flange 46 can, for example, be made of Inconel, and for example of Inconel with a coefficient of expansion approximately equal to 12 x 10⁻⁶ m / m / °C, and have connecting tabs 50 with a length of 100 mm.The sealing elements can be made of oxide-oxide ceramic, for example, oxide-oxide ceramic with a coefficient of thermal expansion of approximately 7 x 10⁻⁶ m / m / °C. In the aforementioned example, the difference in elongation between the connecting tabs 50 and the sealing elements 60 will then be approximately 0.35 mm for a temperature rise of 700°C. For example, the elongation of a steel connecting tab can be calculated by multiplying the length by the temperature rise and by the coefficient of thermal expansion: 100 mm x 700°C x 12 x 10⁻⁶ = 0.84 mm, and the elongation of a ceramic sealing element can be calculated in the same way: 100 mm x 700 x 7 x 10⁻⁶ = 0.49 mm.

[0139] The difference in elongation is then equal to the difference between the two elongations, therefore 0.84-0.49 = 0.35 mm.

[0140] Two circumferentially consecutive and adjacent sealing elements 60 can form a flush assembly so as to present circumferentially an aerodynamic surface without offset.

[0141] The invention further relates to a turbomachine comprising the turbomachine assembly as described above.

[0142] The invention finds application for connecting ducts in a turbomachine where the aerodynamic duct is located outside the ducts, i.e., for a convex duct. This is, for example, the case for an ejection cone.

[0143] The invention also finds application for connecting ducts in a turbomachine where the aerodynamic duct is located inside the ducts, i.e., for a convex duct. This is the case, for example, for a nozzle.

[0144] The invention can be applied to monolithic or acoustic ducts based on SiC-SiC, or to various types of ducts, whether non-acoustic, high-frequency with small cavities, or low-frequency with large cavities. These ducts can be designed in two configurations: as a complete 360° duct or as a duct sector, for example, covering approximately 180°.

[0145] An advantage of the invention is that the aerodynamic surface does not exhibit any significant offset between the first component 40 and the second component 30 regardless of the operating temperature of the turbomachine, in particular neither between the annular part 47 and the sealing element 60, nor between the sealing element 60 and the annular wall 44.

[0146] Another advantage of the invention is that the aerodynamic surface maintains a constant space between two vein elements, regardless of the system temperature.

[0147] Another advantage of the invention is that the arrangement of the sealing elements 60 and the degrees of freedom resulting from this arrangement make it possible to avoid parasitic mechanical stresses in the different parts of the turbomachine assembly described.

Claims

DEMANDS 1. Assembly for longitudinal axis (X) turbomachine comprising: - a first ceramic component (40) comprising an annular wall (44), - a second metallic component (30) arranged upstream of the first component (40), and - a connecting flange (46) arranged longitudinally between the first component (40) and the second component (30), the connecting flange (46) comprising an annular part (47) which is fixed to the second component (30) and connecting lugs (50) extending longitudinally downstream from the annular part (47), the connecting lugs (50) being distributed circumferentially around the longitudinal axis (X), each connecting lug (50) being connected to the annular wall (44) of the first component (40), - a plurality of sealing elements (60) distributed circumferentially adjacent to each other around the longitudinal axis (X), one or more sealing elements (60) among the plurality of sealing elements (60) closing at least one space (51) circumferentially delimited between a first connecting lug (50) and a second connecting lug (50) circumferentially consecutive, each sealing element (60) comprising a sealing plate (70) extending longitudinally at least from the annular part (47) to the annular wall (44) and ensuring with the annular part (47) and / or the annular wall (44) an aerodynamic surface continuity.

2. Turbomachine assembly according to claim 1 in which at least one sealing element (60), preferably each sealing element (60), comprises a downstream tab (78) which extends longitudinally downstream from the sealing plate (70), the downstream tab (78) bearing in the radial direction against the annular wall (44) of the first component (40).

3. Turbomachine assembly according to any one of claims 1 or 2 wherein each sealing member (60) has an upstream end (79) which extends longitudinally upstream from the sealing plate (70), the upstream end (79) being applied, in the radial direction, to the annular part (47) of the connecting flange (46).

4. Turbomachine assembly according to any one of the preceding claims in which an intermediate zone (300) is formed between two sealing elements (60) circumferentially adjacent and consecutive, each intermediate zone (300) being radially aligned with a location of a connecting leg (50).

5. Turbomachine assembly according to claim 4 in which two circumferentially adjacent and consecutive sealing elements (60) are, at least partially, in contact with the connecting lug (50) at the intermediate zone (300) and jointly exert pressure on said connecting lug (50) in the radial direction.

6. Turbomachine assembly according to claim 4 in which a joint (90) is arranged radially between the intermediate zone (300) and the connecting lug (50) with which said intermediate zone (300) is radially aligned.

7. Turbomachine assembly according to any one of the preceding claims wherein the sealing plate (70) has an external face (71) and an internal face (80) opposite the external face (71), and each sealing member (60) includes a lateral tab (200) extending laterally from the sealing plate (70) and configured to bear radially against the internal face (80) of the sealing plate (70) of the circumferentially consecutive sealing member (60).

8. Assembly for turbomachine according to any one of claims 3 to 7 in which the upstream ends (79) of the sealing members (60) are connected together by a continuous ring.

9. Assembly for turbomachine according to any one of claims 3 to 7 wherein the upstream ends (79) of the sealing members (60) are fixed to the annular part (47) of the connecting flange (46) and the downstream tabs (78) of the sealing members slide on the annular wall (44).

10. Turbomachine comprising the turbomachine assembly according to any one of the preceding claims.

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