GB2606552A

GB2606552A - Sealing system for gas turbine engine

Info

Publication number: GB2606552A
Application number: GB2106798.8A
Authority: GB
Inventors: Rodrigo Monux Sergio
Original assignee: Itp Next Generation Turbines S L
Current assignee: Itp Next Generation Turbines S L
Priority date: 2021-05-13
Filing date: 2021-05-13
Publication date: 2022-11-16
Anticipated expiration: 2041-05-13
Also published as: GB2606552B; GB202106798D0

Abstract

A sealing system 600 for a gas turbine engine 10 includes a plurality of sealing segments 602 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10. Each sealing segment 602 is formed by Additive Layer Manufacturing ALM as one part and includes a static seal segment 604. The static seal segments 604 of the plurality of the sealing segments 602 are disposed adjacent to each other to together form a static seal member 416a having a circumferential extent of 360 degrees. A rotating seal member 412 is disposed radially inwards of the static seal member 416a, such that an annular seal 417 is formed between the rotating seal member 412 and the static seal member 416a. The adjacent sealing segments 602 from the plurality of sealing segments 602 may be coupled to each other.

Description

SEALING SYSTEM FOR GAS TURBINE ENGINE

FIELD OF THE DISCLOSURE

The present disclosure relates to a sealing system, and in particular a sealing system 5 for a gas turbine engine.

BACKGROUND

A gas turbine engine typically includes stator stages alternating with rotor stages. An interstage seal is provided between two rotor stages. The interstage seal typically includes an annular sealing element arranged radially relative to a rotational axis of the gas turbine engine. The interstage seal is coupled to a platform of a stator disposed between the two rotor stages. The interstage seal reduces fluid leakages between the two rotor stages to reduce or prevent losses, which otherwise affects the efficiency of the gas turbine engine.

Conventionally, the interstage seal includes parts manufactured by forging and/or sheet metal, with welding lines and/or mechanical fasteners. However, such manufacturing methods add unnecessary extra material to the interstage seal that may further increase weight of the interstage seal and may damage fins which rub against the interstage seal during the operation of the gas turbine engine.

SUMMARY

According to a first aspect there is provided a sealing system for a gas turbine engine having a principal rotational axis. The sealing system includes a plurality of sealing segments disposed adjacent to each other around the principal rotational axis of the gas turbine engine. The adjacent sealing segments from the plurality of sealing segments are coupled to each other. Each sealing segment is formed by Additive Layer Manufacturing (ALM) as one part and includes a static seal segment. The static seal segments of the plurality of the sealing segments are disposed adjacent to each other to together form a static seal member having a circumferential extent of 360 degrees. The sealing system further includes a rotating seal member disposed radially inwards of the static seal member such that an annular seal is formed between the rotating seal member and the static seal member.

A conventional static seal may include an array of polygonal cells formed by welding 5 together corrugated metal sheets. Therefore, the array of polygonal cells may have double walls, i.e., two walls engaging each other. The double walls may lead to addition of extra material to the static seal. By forming the static seal segment of each sealing segment by ALM, the double walls between the polygonal cells may be eliminated. Therefore, the static seal member formed by the plurality of the sealing segments 10 disposed adjacent to each other may be lighter in weight and may have a lesser volume. Further, forming the static seal member by the plurality of static seal segments may provide a greater degree of freedom in terms of design and/or fabrication of the static seal member. For example, individual static seal segments may be optimized as per application requirements.

In some embodiments, the sealing system includes a backing plate disposed adjacent to the static seal member. The backing plate includes a first surface facing the static seal segments and a second surface opposite to the first surface. In some embodiments, the sealing system further includes a front leg extending at least radially outwards from the second surface of the backing plate. In some embodiments, the sealing system further includes a rear leg axially spaced apart from the front leg and extending radially with respect to the backing plate.

The backing plate may provide a support structure to the static seal member and allow the static seal member to be connected to other components of the sealing system.

In some embodiments, each sealing segment includes a backing plate segment. The 25 backing plate segments of the plurality of the sealing segments are disposed adjacent to each other to together form the backing plate.

Dividing the backing plate into multiple backing plate segments may facilitate fabrication and optimization of the backing plate as per application requirements.

In some embodiments, each sealing segment includes an intermediate plate disposed 30 between the backing plate and the static seal segment.

The intermediate plate may facilitate coupling of the static seal segment to the backing plate.

In some embodiments, the backing plate is a single integral part coupled to the plurality of sealing segments.

In some embodiments, each sealing segment includes a front leg segment. The front leg segments of the plurality of the sealing segments are disposed adjacent to each other to together form the front leg In some embodiments, the front leg is a single integral part coupled to the backing plate.

In some embodiments, the sealing system includes a flow control arm extending at least axially from the front leg.

The flow control arm may optimize fluid flow proximal to the sealing system.

In some embodiments, each sealing segment includes a flow control arm segment. The flow control arm segments of the plurality of the sealing segments are disposed adjacent to each other to together form the flow control arm.

Dividing the flow control arm into multiple flow control arm segments may facilitate fabrication and optimization of the flow control arm as per application requirements.

In some embodiments, the flow control arm is a single integral part coupled to the front leg.

In some embodiments, each sealing segment includes a deflector segment extending 20 from the flow control arm segment and inclined relative to the flow control arm segment. The deflector segments of the plurality of the sealing segments are disposed adjacent to each other to together form a deflector.

The deflector may further optimize fluid flow proximal to the sealing system. Further, dividing the deflector into multiple deflector segments may facilitate fabrication and 25 optimization of the deflector as per application requirements.

In some embodiments, each sealing segment further includes a rear leg segment. The rear leg segments of the plurality of the sealing segments are disposed adjacent to each other to together form the rear leg.

Dividing the rear leg into multiple rear leg segments may facilitate fabrication and optimization of the rear leg as per application requirements.

In some embodiments, each sealing segment includes a first circumferential end and a second circumferential end opposite to the first circumferential end. Each sealing segment includes a tab disposed at the first circumferential end and defining a first aperture therethrough. Each sealing segment includes a second aperture disposed proximal to the second circumferential end.

The tab and the second aperture may facilitate coupling of a corresponding sealing segment to adjacent sealing segments at the respective first and second circumferential 10 ends.

In some embodiments, each sealing segment further includes a third aperture circumferentially disposed between the first aperture and the second aperture. The third aperture is configured to couple a corresponding sealing segment to a stator.

The third aperture may provide an additional attachment point to a corresponding 15 sealing segment to reliably retain the corresponding sealing segment in a desired position. The third aperture may further provide a fail-safe coupling of the corresponding sealing segment to the stator.

In some embodiments, each sealing segment includes a first hook disposed proximal to the first circumferential end and a second hook disposed proximal to the second circumferential end. Each of the first hook and the second hook is configured to couple a corresponding sealing segment to a stator.

The first and second hooks may provide reliable coupling between the corresponding sealing segment and the stator, thereby securing the corresponding sealing segment in a desired position.

In some embodiments, each sealing segment includes at least one sealing protrusion disposed at the first circumferential end and at least one sealing slot disposed at the second circumferential end.

The at least one sealing protrusion and the at least one sealing slot may provide sealing between a corresponding sealing segment and adjacent sealing segments at the 30 respective first and second circumferential ends.

In some embodiments, for an intermediate sealing segment disposed between a first adjacent sealing segment and a second adjacent sealing segment, the first circumferential end of the intermediate sealing segment is disposed adjacent to the second circumferential end of the first adjacent sealing segment and the second circumferential end of the intermediate sealing segment is disposed adjacent to the first circumferential end of the second adjacent sealing segment. The first aperture of the intermediate sealing segment is aligned with the second aperture of the first adjacent sealing segment for coupling the intermediate sealing segment to the first adjacent sealing segment. The second aperture of the intermediate sealing segment is aligned with the first aperture of the second adjacent sealing segment for coupling the intermediate sealing segment to the second adjacent sealing segment. The at least one sealing protrusion of the intermediate sealing segment is at least partially received in the at least one sealing slot of the first adjacent sealing segment. The at least one sealing slot of the intermediate sealing segment at least partially receives the at least sealing protrusion of the second adjacent sealing segment.

Therefore, the sealing protrusion may act as a strip seal. The engagement of the at least one sealing protrusion and the at least one sealing slot of the adjacent sealing segment may prevent unintended leakages between a first rotor stage and a second rotor stage.

In some embodiments, each sealing segment includes a first interface surface disposed at the first circumferential end and a second interface surface disposed at the second circumferential end.

In some embodiments, each of the first interface surface and the second interface surface includes a planar surface inclined obliquely relative to a circumferential 25 direction.

Each of the first interface surface and the second interface surface including the planar surface may be easily formed by ALM. The planar surface inclined obliquely relative to the circumferential direction may provide a higher axial stiffness to a corresponding sealing segment.

In some embodiments, each of the first interface surface and the second interface surface includes a plurality of planar surfaces inclined relative to each other. Each planar surface is inclined obliquely relative to a circumferential direction.

The plurality of planar surfaces inclined relative to each other may help in locating and interlocking the adjacent sealing segments. Further, the plurality of planar surfaces inclined obliquely relative to the circumferential direction may also provide a higher axial stiffness to a corresponding sealing segment.

In some embodiments, the static seal segment of each sealing segment includes a honeycomb structure.

The honeycomb structure may form an abradable structure that is configured to rub against the rotating seal member during operation of the gas turbine engine.

In some embodiments, the rotating seal member includes a plurality of fins extending 10 towards the static seal member.

Since, the static seal segment of each sealing segment is formed by ALM, double walls between the polygonal cells of the static seal segment may be eliminated. Thus, the plurality of fins may have to erode or abrade a less amount of material during an eventual rub with the static seal member. This may substantially reduce heat generation and damage to the fins. In addition, the static seal member including the plurality of the sealing segments formed by ALM may further eliminate a need of a protective coating on the fins.

In some embodiments, the adjacent sealing segments define a circumferential gap therebetween.

The circumferential gap between the adjacent sealing segments may allow thermal expansion and contraction of the sealing segments.

According to a second aspect, there is provided a gas turbine engine. The gas turbine engine includes a rotor disc configured to rotate about a principal rotational axis. The gas turbine engine includes a first rotor stage including an annular array of first rotor blades extending from the rotor disc. The gas turbine engine further includes a second rotor stage including an annular array of second rotor blades extending from the rotor disc and disposed downstream of the first rotor blades. The gas turbine engine further includes a stator disposed axially between the first rotor stage and the second rotor stage. The stator includes a platform and an annular array of stator vanes extending from the platform. The gas turbine engine also includes the sealing system of the first aspect. The plurality of sealing segments and the rotating seal member are disposed axially between the first rotor stage and the second rotor stage.

In some embodiments, each of the plurality of sealing segments is coupled to the platform of the stator.

The overall size and shape of the sealing segments may be varied conveniently using ALM as per application requirements. Further, materials used for forming the sealing segments may be varied conveniently using ALM. For example, the material may include one or more of: steel and its alloys, aluminium and its alloys, titanium and its alloys, nickel and its alloys, copper and its alloys, polymers, metal coated polymers, and composite materials. Furthermore, the sealing segments may be built from a model file. Therefore, the sealing segments may be adapted to suit applications having varying size, shape, weight, and stiffness requirements. In some embodiments, the sealing segments may be manufactured using ALM to suit individual requirements based on characteristics derived from computer simulations. For example, one or more sealing segments may be designed differently from the other sealing segments to cater to certain application requirements.

Moreover, forming the plurality of sealing segments instead of a single piece sealing segment may make the fabrication and/or optimization of the sealing segments by ALM easier. Further, including the plurality of sealing segments instead of the single piece 20 sealing segment may further reduce the cost of repairs.

Further, forming the plurality of sealing segments by ALM may enable adding three-dimensional features, such as the backing plate segment, the front leg segment, the flow control arm segment, and the rear leg segment, to the plurality of sealing segments. Integrating the three-dimensional features in each sealing segment may further reduce the cost of manufacturing and repairs. In addition, the three-dimensional features may further include deflectors, stiffeners, and so forth.

The skilled person will appreciate that except where mutually exclusive, a feature or parameter described in relation to any one of the above aspects may be applied to any other aspect. Furthermore, except where mutually exclusive, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only, with reference to the Figures, in which: Figure 1 is a sectional side view of a gas turbine engine; Figure 2 is an enlarged partial sectional side view of a gas turbine engine; Figures 3A and 3B illustrate sectional views of sealing systems, according to embodiments of the present disclosure; Figures 4A-4B to 10A-10B illustrate sectional views of sealing systems, according to embodiments of the present disclosure; Figure 11 illustrates a perspective view of a sealing segment, according to an embodiment of the present disclosure; Figures 12A and 12B illustrate perspective views of a sealing segment, according to another embodiment of the present disclosure; Figures 13A and 13B illustrate perspective views of adjacent sealing segments in an 15 unassembled state and an assembled state, respectively, according to an embodiment of the present disclosure; Figures 14A, 14B and 14C illustrate top views of adjacent sealing segments, according to embodiments of the present disclosure; and Figure 15 illustrates a partial schematic view of a plurality of sealing segments coupled 20 to a stator, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Aspects and embodiments of the present disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be 25 apparent to those skilled in the art.

As used herein, a component extends "axially" relative to an axis if the component extends along the axis. A component extends "circumferentially" relative to an axis if the component extends in a circumferential direction defined around the axis. A component extends "radially" relative to an axis if the component extends radially inward or outward relative to the axis. If a first component is disposed "radially outward" of a second component, the first component is disposed at a greater radial distance from an axis as compared to the second component. If a first component is disposed "radially inward" of a second component, the first component is disposed at a less radial distance from an axis as compared to the second component.

Figure 1 illustrates a gas turbine engine 10 having a principal rotational axis 9. The engine 10 comprises an air intake 12 and a propulsive fan 23 that generates two airflows: a core airflow A and a bypass airflow B. The gas turbine engine 10 comprises a core 11 that receives the core airflow A. The engine core 11 comprises, in axial flow series, a low-pressure compressor 14, a high-pressure compressor 15, combustion equipment 16, a high-pressure turbine 17, a low-pressure turbine 19 and a core exhaust nozzle 20. A nacelle 21 surrounds the gas turbine engine 10 and defines a bypass duct 22 and a bypass exhaust nozzle 18. The bypass airflow B flows through the bypass duct 22. The fan 23 is attached to and driven by the low-pressure turbine 19 via a shaft 26 and an epicyclic gearbox 30.

In use, the core airflow A is accelerated and compressed by the low-pressure compressor 14 and directed into the high-pressure compressor 15 where further compression takes place. The compressed air exhausted from the high-pressure compressor 15 is directed into the combustion equipment 16 where it is mixed with fuel and the mixture is combusted. The resultant hot combustion products then expand through, and thereby drive, the high pressure and low-pressure turbines 17, 19 before being exhausted through the core exhaust nozzle 20 to provide some propulsive thrust. The high-pressure turbine 17 drives the high-pressure compressor 15 by a suitable interconnecting shaft 27. The fan 23 generally provides the majority of the propulsive thrust. The epicyclic gearbox 30 is a reduction gearbox.

Note that the terms "low pressure turbine" and "low pressure compressor" as used herein may be taken to mean the lowest pressure turbine stages and lowest pressure compressor stages (i.e. not including the fan 23) respectively and/or the turbine and compressor stages that are connected together by the interconnecting shaft 26 with the lowest rotational speed in the engine (i.e. not including the gearbox output shaft that drives the fan 23). In some literature, the "low pressure turbine" and "low pressure compressor" referred to herein may alternatively be known as the "intermediate pressure turbine" and "intermediate pressure compressor". Where such alternative nomenclature is used, the fan 23 may be referred to as a first, or lowest pressure, compression stage.

Accordingly, the present disclosure extends to a gas turbine engine having any arrangement of gearbox styles (for example star or planetary), support structures, input, and output shaft arrangement, and bearing locations.

Optionally, the gearbox 30 may drive additional and/or alternative components (e.g. the intermediate pressure compressor and/or a booster compressor).

Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. For example, such engines may have an alternative number of compressors and/or turbines and/or an alternative number of interconnecting shafts.

By way of further example, the gas turbine engine 10 has a split flow nozzle 18, 20 meaning that the flow through the bypass duct 22 has its own nozzle 18 that is separate to and radially outside the core exhaust nozzle 20. However, this is not limiting, and any aspect of the present disclosure may also apply to engines in which the flow through the bypass duct 22 and the flow through the core 11 are mixed, or combined, before (or upstream of) a single nozzle, which may be referred to as a mixed flow nozzle. One or both nozzles (whether mixed or split flow) may have a fixed or variable area. Whilst the described example relates to a turbofan engine, the disclosure may apply, for example, to any type of gas turbine engine, such as an open rotor (in which the fan stage is not surrounded by a nacelle) or turboprop engine, for example. In some arrangements, the gas turbine engine 10 may not comprise a gearbox 30.

The geometry of the gas turbine engine 10, and components thereof, is defined by a conventional axis system, comprising an axial direction X (which is aligned with the principal rotational axis 9), a radial direction R On the bottom-to-top direction), and a circumferential direction C (perpendicular to the page). The axial, radial and circumferential directions X, R, C are mutually perpendicular.

In addition, the present invention is equally applicable to aero gas turbine engines, marine gas turbine engines and land-based gas turbine engines.

Each of the high pressure turbine 17 and the low pressure turbine 19 of the gas turbine engine 10 may include one or more rows of stators (not shown in Figure 1) alternating with one or more rows of rotors (not shown in Figure 1). A stator and a rotor immediately downstream of the stator may form a stage. The stator may include an annular array of radially extending stator vanes. The rotor may include an annular array of radially extending rotor blades mounted to a rotor disc. The combustion gases impinge on the stator vanes which present the gases at an appropriate angle to efficiently drive the rotor blades. The one or more rows of stators and one or more rows of rotors may form a blade assembly for the gas turbine engine 10.

Figure 2 illustrates a sectional side view of the gas turbine engine 10 (shown in Figure 1). Figure 2 may correspond to a detail D shown in Figure 1. Specifically, Figure 2 illustrates an enlarged partial sectional view of the gas turbine engine 10.

The gas turbine engine 10 includes a rotor disc 402 configured to rotate about the principal rotational axis 9. The gas turbine engine 10 includes a first rotor stage 404 and a second rotor stage 406. The first rotor stage 404 includes an annular array of first rotor blades 405 extending from the rotor disc 402. The second rotor stage 406 includes an annular array of second rotor blades 407 extending from the rotor disc 402 and disposed downstream of the first rotor blades 405. The gas turbine engine 10 further includes a stator 408 disposed axially between the first rotor stage 404 and the second rotor stage 406. The stator 408 includes a platform 408a and an annular array of stator vanes 409 extending from the platform 408a. The stator 408 further includes a vane inner rail 408b extending radially inward from the platform 408a of the stator 408.

In some embodiments, the gas turbine engine 10 further includes a sealing ring 410 coupled to the rotor disc 402. In the illustrated embodiment of Figure 2, the sealing ring 410 is integral with the rotor disc 402. In some other embodiments, the sealing ring 410 may not be integral with the rotor disc 402. In some embodiments, the sealing ring 410 may be coupled to the rotor disc 402 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. In some embodiments, the sealing ring 410 includes a rotating seal member 412 disposed axially between the first rotor stage 404 and the second rotor stage 406. In some embodiments, the rotating seal member 412 includes a plurality of fins 412a extending radially outwards. In the illustrated embodiment of Figure 2, the rotating seal member 412 is integral with the rotor disc 402.

In some embodiments, the sealing ring 410 may be integral with the first rotor stage 404. In such embodiments, the sealing ring 410 may be coupled to the second rotor stage 406 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. In some other embodiments, the sealing ring 410 may be integral with the second rotor stage 406. In such embodiments, the sealing ring 410 may be coupled to the first rotor stage 404 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

In some other embodiments, the sealing ring 410 may have a two part configuration (not shown). Specifically, a first part of the sealing ring 410 may be integral with the first rotor stage 404 and a second part of the sealing ring 410 may be integral with the second rotor stage 406. In such embodiments, the rotating seal member 412 may also have a two part configuration and the first and second parts of the sealing ring 410 may together form the rotating seal member 412. In some embodiments, the first part of the sealing ring 410 may include the plurality of fins 412a. In some other embodiments, the second part of the sealing ring 410 may include the plurality of fins 412a. In some other embodiments, the first and second parts of the sealing ring 410 may include the plurality of fins 412a. In some embodiments, the first and second parts of the sealing ring 410 may be coupled to each other by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. In some embodiments, the first and second parts of the sealing ring 410 may include first and second flanges (not shown), respectively, to couple the first and second parts of the sealing ring 410 together by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

The gas turbine engine 10 further includes a sealing system 416. The sealing system 416 is disposed axially between the first rotor stage 404 and the second rotor stage 406. In some embodiments, the sealing system 416 may include a labyrinth seal. The sealing system 416 forms an interstage seal between the first rotor stage 404 and the second rotor stage 406 of the gas turbine engine 10. In the illustrated embodiment of Figure 2, the sealing system 416 includes a static seal member 416a. In some embodiments, the static seal member 416a includes an array of polygonal cells (not shown). The polygonal cells may be, but not limited to, hexagonal, octagonal, pentagonal, or quadrilateral. In some embodiments, the sidewalls of each polygonal cell may have an equal length. In some other embodiments, the sidewalls of each polygonal cell may have unequal lengths. In some embodiments, the static seal member 416a includes a honeycomb structure. Each cell in the honeycomb structure may have a similar or a substantially similar shape. The static seal member 416a forms an annular seal 417 against the rotating seal member 412.

In some embodiments, the sealing system 416 further includes a backing plate 416b disposed adjacent to the static seal member 416a. The backing plate 416b includes a first surface SF facing the static seal member 416a and a second surface Ss opposite to the first surface SF. In some embodiments, the backing plate 416b is a single integral part having an annular shape and a circumferential extent of 360 degrees around the principal rotational axis 9. In some embodiments, the backing plate 416b may be coupled to the static seal member 416a by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

In some embodiments, the sealing system 416 further includes a front leg 416c extending at least radially outwards from the second surface Ss of the backing plate 416b. In the illustrated embodiment of Figure 2, the front leg 416c is at least partially disposed on the second surface Ss of the backing plate 416b. In some embodiments, the front leg 416c is a single integral part having an annular shape and a circumferential extent of 360 degrees around the principal rotational axis 9. In some embodiments, the front leg 416c may be coupled to the backing plate 416b by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

In some embodiments, the sealing system 416 further includes a flow control arm 416f extending at least axially from the front leg 416c. The flow control arm 416f is radially spaced apart from the backing plate 416b. In some embodiments, the flow control arm 416f extends at least radially towards the first rotor stage 404. In some embodiments, the flow control arm 416f is inclined obliquely relative to the principal rotational axis 9. In the illustrated embodiment of Figure 2, the flow control arm 416f may be inclined in an upward direction relative to the principal rotational axis 9. In some other embodiments, the flow control arm 416f may be inclined in a downward direction relative to the principal rotational axis 9. The flow control arm 416f therefore extends both radially and axially relative to the front leg 416c of the sealing system 416. In some embodiments, the flow control arm 416f further includes a tip distal to the front leg 416c of the sealing system 416. In some embodiments, the sealing system 416 further includes a deflector (not shown in Figure 2) extending from the flow control arm 416f and inclined relative to the flow control arm 416f. In some embodiments, the flow control arm 416f is a single integral part having an annular shape and a circumferential extent of 360 degrees around the principal rotational axis 9. In some embodiments, the flow control arm 416f may be coupled to the front leg 416c by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. In some other embodiments, the 10 flow control arm 416f may be integral with the front leg 416c.

In some embodiments, the sealing system 416 further includes a rear leg 416d axially spaced apart from the front leg 416c. In some embodiments, the rear leg 416d extends radially with respect to the backing plate 416b. In the illustrated embodiment of Figure 2, the rear leg 416d extends at least radially outwards from the second surface Ss the backing plate 416b. In some embodiments, the rear leg 416d is a single integral part having an annular shape and a circumferential extent of 360 degrees around the principal rotational axis 9. In such embodiments, the rear leg 416d may be coupled to the backing plate 416b by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. In some other embodiments, the rear leg 416d may not extend from the backing plate 416b. In other words, in some other embodiments, the rear leg 416d may not be disposed on the backing plate 416b. In some other embodiments, the rear leg 416d may extend from the front leg 416c. In some other embodiments, the rear leg 416d may be radially spaced apart from the backing plate 416b. In such embodiments, 25 the rear leg 416d may be coupled to the front leg 416c by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

In some embodiments, the sealing system 416 further includes a rear flow control arm 416e extending axially from the rear leg 416d. In some embodiments, the rear flow control arm 416e is a single integral part having an annular shape and a circumferential extent of 360 degrees around the principal rotational axis 9. In some embodiments, the rear flow control arm 416e may be coupled to the rear leg 416d by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. In some other embodiments, the rear flow control arm 416e may be integral with the rear leg 416d.

In some embodiments, the flow control arm 416f and the rear flow control arm 416e of the sealing system 416 may have a substantially similar shape and substantially similar 5 dimensions.

In the illustrated embodiment of Figure 2, the sealing system 416 forms first second and third flow cavities 460, 462, 464, respectively. The first and second flow cavities 460 and 462 are formed between the stator 408 and the first rotor stage 404 and the third flow cavity 464 is formed between the stator 408 and the second rotor stage 406.

Specifically, the sealing system 416 and the first rotor stage 404 define the first and second flow cavities 460, 462 therebetween and the sealing system 416 and the second rotor stage 406 define the first and the third flow cavity 464 therebetween. Therefore, the sealing system 416 seals the third flow cavity 464 from the first and second flow cavities 460, 462. As discussed above, the sealing system 416 forms the interstage seal between the first rotor stage 404 and the second rotor stage 406 of the gas turbine engine 10. Further, the first and second flow cavities 460, 462 are separated by the flow control arm 416f of the sealing system 416. The flow control arm 416f may control fluid flow between the first cavity 460 and a hot gas flow path (not shown) of the gas turbine engine 10. A rear projection 419 of the first rotor stage 404 may further control fluid flow in the first cavity 460.

In some embodiments, the sealing ring 410 defines an aperture 414 therethrough in fluid communication with the second flow cavity 462. The second flow cavity 462 may therefore receive a cooling fluid from the aperture 414 defined in the sealing ring 410. The aperture 414 may be one of an array of circumferentially spaced apart apertures defined through the sealing ring 410. The aperture 414 may have any suitable shape, for example, circular, elliptical, oval, polygonal, and so forth. In some embodiments, the cooling fluid may be a cooling air bled from a flow from a compressor (e.g., the low pressure compressor 14 shown in Figure 1) of the gas turbine engine 10. The flow control arm 416f of the sealing system 416 may deflect at least a portion of the cooling fluid entering the second flow cavity 462, thereby decreasing the temperature of the second flow cavity 462 and then exit the second flow cavity 462 to enter the first flow cavity 460. The flow control arm 416f of the sealing system 416 may improve mixing of the cooling fluid and may result in better cooling of the second flow cavity 462.

As discussed above, the rotating seal member 412 includes the plurality of fins 412a extending radially outwards. Specifically, the plurality of fins 412a extends towards the static seal member 416a. The fins 412a provide a seal against the static seal member 416a of the sealing system 416. The sealing system 416 may create a resistance to cooling fluid flow by forcing the cooling fluid to traverse through the fins 412a. However, during operation, a relatively small amount of the cooling fluid may pass through the sealing system 416 from the second flow cavity 462 to the third flow cavity 464 to provide cooling thereto.

The sealing system 416 may aim to minimise the performance penalties from the cooling fluid leaking across the stator 408, and across the first, second, and third flow cavities 460, 462, 464.

The flow control arm 416f of the sealing system 416 may further restrict flow of hot combustion core gases (such as the core airflow A, shown in Figure 1) from entering the second flow cavity 462. This may improve a specific fuel consumption (SFC) of the gas 15 turbine engine 10 and/or allow use of lower cost materials.

In some embodiments, a static portion of the sealing system 416 is coupled to the platform 408a of the stator 408. The static portion of the sealing system 416 includes at least the static seal member 416a, the backing plate 416b, the front leg 416c, and the rear leg 416d. Specifically, the static portion of the sealing system 416 is coupled to the vane inner rail 408b. The static portion of the sealing system 416 is coupled to the platform 408a of the stator 408 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. A rotating portion of the sealing system 416 includes at least the rotating seal member 412 coupled to the rotor disc 402. In the embodiment illustrated in Figure 2, the sealing system 416 has an annular shape and has a circumferential extent of 360 degrees around the principal rotational axis 9 of the gas turbine engine 10.

Figures 3A and 3B illustrate sectional views of sealing systems 450, 500, respectively. The rotating portions of the sealing systems 450, 500 are omitted in Figures 3A and 3B 30 for the purpose of clarity.

The sealing system 450 is substantially similar to the sealing system 416, as illustrated in Figure 2. The sealing system 450 includes the static seal member 416a, the backing plate 416b, and the front leg 416c. However, the sealing system 450 includes a rear leg 502 having a different configuration from the rear leg 416d of Figure 2. The rear leg 502 is radially spaced apart from the backing plate 416b and coupled to the front leg 416c. The rear leg 502 may be substantially L-shaped, as illustrated in Figure 3A. The sealing system 450 further includes the rear flow control arm 416e and the flow control arm 416f. In some embodiments, the rear flow control arm 416e may be integral with the rear leg 502. In some other embodiments, one or more of the flow control arm 416f and the rear flow control arm 416e may not be present.

The sealing system 500 is substantially similar to the sealing system 416, as illustrated in Figure 2. The sealing system 500 includes the static seal member 416a, the backing plate 416b, and the front leg 416c. However, the sealing system 500 includes a rear leg 504 having a different configuration from the rear leg 416d of Figure 2. The rear leg 504 is not coupled to the backing plate 416b. Further, the rear leg 504 is not directly coupled to the front leg 416c. The rear leg 504 is also radially spaced apart from the backing plate 416b. In the illustrated embodiment of Figure 3B, the rear leg 504 is indirectly coupled to the front leg 416c. A spacer bush 506 may be provided between the front leg 416c and the rear leg 504. The vane inner rail 408b (shown in Figure 2) of the stator 408 may be then received between the front leg 416c and the rear leg 504. Figure 3B illustrates the front leg 416c, the rear leg 502, the flow control arm 416f and the spacer bush 506 coupled to each other with a fastener 508. The fastener 508 may include, for example, nut and bolt assemblies, screws, rivets, and so forth. In some embodiments, the fastener 508 may include a two-part fastener, such as a HilockTM type fastener. The front leg 416c, the rear leg 504, the flow control arm 416f, and the spacer bush 506 may include respective apertures (not shown) of any suitable dimension to receive the fastener 508. The sealing system 500 further includes the rear flow control arm 416e and the flow control arm 416f. In some embodiments, the rear flow control arm 416e may be integral with the rear leg 504. In some other embodiments, one or more of the flow control arm 416f and the rear flow control arm 416e may not be present.

In some embodiments, each of the backing plate 416b, the front leg 416c, the rear leg 416d, 502, 504, the rear flow control arm 416e, and the flow control arm 416f of the sealing systems 416, 450 and 500 shown in Figures 2 and 3A-3B is formed of a sheet metal. In some embodiments, each of the backing plate 416b, the front leg 416c, the rear leg 416d, 502, 504, the rear flow control arm 416e, and the flow control arm 416f may be formed by forging. In some embodiments, the backing plate 416b, the front leg 416c, the rear leg 416d, 502, 504, the rear flow control arm 416e, and the flow control arm 416f of the sealing systems 416, 450 and 500 may be formed as a single integral part. In some embodiments, the static seal member 416a may be coupled to the single integral part.

As discussed above, the static seal member 416a includes the array of polygonal cells. In conventional seals, corrugated metal sheets are welded together to form the array of polygonal cells. Therefore, the array of polygonal cells has double walls. The double walls may lead to addition of extra material to the static seal member 416a. The extra material increases the weight of the static seal member 416a and consequently increases the weight and volume of the sealing system 416, 450, 500. Further, the fins 412a may eventually rub against the static seal member 416a to erode a portion of the static seal member 416a. The extra material the fins 412a may have to erode may increase heat generation and may cause damages to the fins 412a. Specifically, the increased heat generation may generate cracks in the fins 412a during the eventual rub. Further, due to limitations of conventional manufacturing processes, the array of polygonal cells is typically axisymmetric.

Figures 4A and 4B illustrate sectional views of sealing systems 600, 650, respectively, according to embodiments of the present disclosure. The sealing systems 600, 650 are substantially similar to the sealing systems 416 and 450, as shown in the Figures 2 and 3A, respectively. The rotating portions of the sealing systems 600, 650 are omitted in Figures 4A and 4B for the purpose of clarity.

In some embodiments, the sealing system 600 includes the backing plate 416b, the front leg 416c, the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f similar to the sealing system 416, as shown in Figure 2. However, the sealing system 600 includes a plurality of sealing segments 602 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 602 from the plurality of sealing segments 602 are coupled to each other. Each sealing segment 602 is formed by Additive Layer Manufacturing (ALM) as one part. In the illustrated embodiment of Figure 4A, each sealing segment 602 includes a static seal segment 604. The static seal segments 604 of the plurality of the sealing segments 602 are disposed adjacent to each other to together form a static seal member having a circumferential extent of 360 degrees. The static seal member having the circumferential extent of 360 degrees formed by the static seal segments 604 disposed adjacent to each other may be substantially similar in shape and size of the static seal member 416a. The first surface SF of the backing plate 416b faces the static seal segment 604. In some embodiments, the backing plate 416b is coupled to the plurality of sealing segments 602. In some embodiments, the backing plate 416b may be coupled to the plurality of the sealing segments 602 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

In some embodiments, the static seal segment 604 of each sealing segment 602 includes an array of polygonal cells. The polygonal cells may be, but not limited to, hexagonal, octagonal, pentagonal, or quadrilateral. In some embodiments, the sidewalls of each polygonal cell may have an equal length. In some other embodiments, the sidewalls of each polygonal cell may have unequal lengths. In some embodiments, the static seal segment 604 of each sealing segment 602 includes a honeycomb structure. Each cell in the honeycomb structure may have a similar or a substantially similar shape. However, the array of polygonal cells of the static seal segment 604 of each sealing segment 602 is formed by ALM. In some embodiments, ALM may include selective laser melting, electron beam melting, blown powder deposition or any other ALM processes. By forming the static seal segment 604 of each sealing segment 602 by ALM, the double walls between the polygonal cells may be eliminated. Therefore, the static seal member formed by the plurality of the sealing segments 602 disposed adjacent to each other may be lighter in weight and may have a lesser volume. In addition, the fins 412a may have to erode less material of the static seal member. This may substantially reduce heat generation and damage to the fins 412a. In some embodiments, the static seal member formed by the plurality of the sealing segments 602 formed by ALM may further eliminate a need of a protective coating on the fins 412a.

In some embodiments, the sealing system 600 further includes the backing plate 416b, the front leg 416c, the rear leg 416d, the rear flow control arm 416e, and the flow control 30 arm 416f, similar to the sealing system 416, as shown in Figure 2.

The sealing system 650 is substantially similar to the sealing system 600, as illustrated in Figure 4A. However, the sealing system 650 includes the rear leg 502.

Figures 5A and 5B illustrate sectional views of sealing systems 700 and 750, respectively, according to embodiments of the present disclosure. The sealing systems 700 and 750 are substantially similar to the sealing systems 600 and 650, as shown in the Figures 4A and 4B, respectively. The rotating portions of the sealing systems 700, 750 are omitted in Figures 5A and 5B for the purpose of clarity.

In some embodiments, the sealing system 700 includes the backing plate 416b, the front leg 416c, the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f similar to the sealing system 600, as shown in Figure 4A. However, the sealing system 700 includes a plurality of sealing segments 702 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 702 from the plurality of sealing segments 702 are coupled to each other. Each sealing segment 702 is formed by ALM as one part. Each sealing segment 702 further includes the static seal segment 604. In addition, each sealing segment 702 further includes an intermediate plate 704 disposed between the backing plate 416b and the static seal segment 604. In other words, the intermediate plate 704 and the static seal segment 604 are integrally formed as the sealing segment 702 which is a single integral part. In some embodiments, the intermediate plate 704 is a thin plate. In some embodiments, the intermediate plates 704 of the plurality of sealing segments 702 are disposed adjacent to each other to together form an intermediate backing plate having a circumferential extent of 360 degrees. In some cases, the intermediate backing plate may be substantially similar to the backing plate 416b. In some other cases, the intermediate backing plate may have thickness different from that of the backing plate 416b. In some embodiments the intermediate backing plate and the backing plate 416b may together form a combined backing plate 706. In some embodiments, the backing plate 416b is coupled to the plurality of sealing segments 702. In some embodiments, the backing plate 416b may be coupled to the plurality of the sealing segments 702 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

In some embodiments, the sealing system 700 further includes the backing plate 416b, the front leg 416c, the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f similar to the sealing system 416, as shown in Figure 2.

The sealing system 750 is substantially similar to the sealing system 700, as illustrated 5 in Figure 5A. However, the sealing system 750 includes the rear leg 502.

As discussed above, in some embodiments, the static seal segment 604 of each sealing segment 702 may include the array of polygonal cells formed by ALM. In some embodiments, the static seal segment 604 of each sealing segment 702 includes the honeycomb structure.

Figures 6A and 65 illustrate sectional views of sealing systems 800 and 850, respectively, according to embodiments of the present disclosure. The sealing systems 800 and 850 are substantially similar to the sealing systems 600 and 650, as shown in the Figures 4A and 4B, respectively. The rotating portions of the sealing systems 800, 850 are omitted in Figures 6A and 6B for the purpose of clarity.

In some embodiments, the sealing system 800 includes the front leg 416c, the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f similar to the sealing system 600, shown in Figure 4A. However, the sealing system 800 includes a plurality of sealing segments 802 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 802 from the plurality of sealing segments 802 are coupled to each other. Each sealing segment 802 is formed by ALM as one part. Each sealing segment 802 includes the static seal segment 604. In addition, each sealing segment 802 further includes a backing plate segment 804. In other words, the backing plate segment 804 and the static seal segment 604 are integrally formed as the sealing segment 802 which is a single integral part. Each backing plate segment 804 includes a first surface 804a facing the static seal segment 604 and a second surface 804b opposite to the first surface 804a. The backing plate segments 804 of the plurality of the sealing segments 802 are disposed adjacent to each other to together form a backing plate having a circumferential extent of 360 degrees. The backing plate having the circumferential extent of 360 degrees formed by the backing plate segments 804 disposed adjacent to each other may be substantially similar in shape and size of the backing plate 416b.

In some embodiments, the sealing system 800 further includes the front leg 416c, the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f, similar to the sealing system 416, as shown in Figure 2.

In some embodiments, the front leg 416c and the rear leg 416d may be coupled to the 5 plurality of sealing segments 802. Specifically, the front leg 416c and the rear leg 416d are coupled to the backing plate segments 804 of the plurality of sealing segments 802. In some embodiments, the front leg 416c and the rear leg 416d may be coupled to the backing plate segments 804 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, 10 adhesives, and the like.

The sealing system 850 is substantially similar to the sealing system 800, as illustrated in Figure 6A. However, the sealing system 850 includes the rear leg 502. The rear leg 502 is not coupled to the plurality of sealing segments 802.

As discussed above, in some embodiments, the static seal segment 604 of each sealing 15 segment 802 may include the array of polygonal cells. In some embodiments, the static seal segment 604 of each sealing segment 802 includes the honeycomb structure.

Figures 7A and 7B illustrate sectional views of sealing systems 900 and 950, respectively, according to embodiments of the present disclosure. The sealing systems 900 and 950 are substantially similar to the sealing systems 800 and 850, as shown in the Figures 6A and 6B, respectively. The rotating portions of the sealing systems 900, 950 are omitted in Figures 7A and 7B for the purpose of clarity.

In some embodiments, the sealing system 900 includes the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f similar to the sealing system 800, as shown in Figure 6A. However, the sealing system 900 includes a plurality of sealing segments 902 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 902 from the plurality of sealing segments 902 are coupled to each other. Each sealing segment 902 is formed by ALM as one part. Each sealing segment 902 includes the static seal segment 604 and the backing plate segment 804. In addition, each sealing segment 902 further includes a front leg segment 904. In other words, the front leg segment 904, the backing plate segment 804, and the static seal segment 604 are integrally formed as the sealing segment 902 which is a single integral part. The front leg segments 904 of the plurality of the sealing segments 902 are disposed adjacent to each other to together form a front leg having a circumferential extent of 360 degrees. The front leg having the circumferential extent of 360 degrees formed by the front leg segments 904 disposed adjacent to each other may be substantially similar in shape and size to a radially extending portion of the front leg 416c. An axially extending portion of the front leg 416c attached to the backing plate 416b is not required in each front leg segment 904 as each front leg segment 904 is integrally formed with the corresponding backing plate segment 804. Hence, weight and size of each sealing segment 902 may be reduced.

In some embodiments, the sealing system 900 further includes the rear leg 416d, the rear flow control arm 416e, and the flow control arm 416f, similar to the sealing system 416, as shown in Figure 2.

In some embodiments, the rear leg 416d may be coupled to the plurality of sealing segments 902. Specifically, the rear leg 416d is coupled to the backing plate segments 804 of the plurality of sealing segments 902. In some embodiments, the rear leg 416d may be coupled to the backing plate segments 804 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

The sealing system 950 is substantially similar to the sealing system 900, as illustrated in Figure 7A. However, the sealing system 950 includes the rear leg 502. In some embodiments, the rear leg 502 is also coupled to the plurality of sealing segments 902. Specifically, the rear leg 502 is coupled to the front leg segments 904 of the plurality of sealing segments 902. In some embodiments, the rear leg 502 may be coupled to the front leg segments 904 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

As discussed above, in some embodiments, the static seal segment 604 of each sealing segment 902 may include the array of polygonal cells. In some embodiments, the static seal segment 604 of each sealing segment 902 includes the honeycomb structure.

Further, each sealing segment 902 formed by ALM includes three-dimensional features, such as the front leg segment 904, that may further improve of the functionality of the sealing systems 900, 950.

Figures 8A to 8C illustrate sectional views of sealing systems 1000 1050, and 1055 respectively, according to embodiments of the present disclosure. The sealing systems 1000 and 1050 are substantially similar to the sealing systems 900 and 950, as shown in the Figures 7A and 7B, respectively. The rotating portions of the sealing systems 1000, 1050, 1055 are omitted in Figures 8A and 8B for the purpose of clarity.

In some embodiments, the sealing system 1000 includes the rear leg 416d and the rear flow control arm 416e of the sealing system 900. However, the sealing system 1000 includes a plurality of sealing segments 1002 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 1002 from the plurality of sealing segments 1002 are coupled to each other. Each sealing segment 1002 is formed by ALM as one part. Each sealing segment 1002 includes the static seal segment 604, the backing plate segment 804, and the front leg segment 904. In addition, each sealing segment 1002 further includes a flow control arm segment 1004. In other words, the flow control arm segment 1004, the front leg segment 904, the backing plate segment 804 and the static seal segment 604 are integrally formed as the sealing segment 1002 which is a single integral part. The flow control arm segments 1004 of the plurality of the sealing segments 1002 are disposed adjacent to each other to together form a flow control arm having a circumferential extent of 360 degrees. The flow control arm having the circumferential extent of 360 degrees formed by the flow control arm segments 1004 disposed adjacent to each other may be substantially similar in shape and size of the flow control arm 416f.

In some embodiments, the sealing system 1000 further includes the rear leg 416d and the rear flow control arm 416e similar to the sealing system 416, as shown in Figure 2.

In some embodiments, the rear leg 416d may be coupled to the plurality of sealing segments 1002. Specifically, the rear leg 416d is coupled to the backing plate segments 804 of the plurality of sealing segments 1002. In some embodiments, the rear leg 416d may be coupled to the backing plate segments 804 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

The sealing system 1050 is substantially similar to the sealing system 1000, as illustrated in Figure 8A. However, the sealing system 1050 includes the rear leg 502. In some embodiments, the rear leg 502 is also coupled to the plurality of sealing segments 1002. Specifically, the rear leg 502 is coupled to the front leg segments 904 of the plurality of sealing segments 1002. In some embodiments, the rear leg 502 may be coupled to the front leg segments 904 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

The sealing system 1055 is substantially similar to the sealing system 1000, as illustrated in Figure 8A. However, the sealing segments 1002 further include a first hook 1401a and a second hook 1401b (shown in Figure 12B). In some embodiments, the first hook 1401a and the second hook 1401b may be integral with the sealing segment 1002 and formed by ALM as one part. In some other embodiments, the first hook 1401a and the second hook 1401b may not be integral with the sealing segment 1002. In some embodiments, the first hook 1401a and the second hook 1401b may be coupled to the front leg segment 904 of the sealing segment 1002. In some embodiments, the first hook 1401a and the second hook 1401b may be coupled to the sealing segment 1002 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like. The first hook 1401a and the second hook 1401b may be configured to couple the sealing segment 1002 to the rear leg 416d. The first hook 1401a and the second hook 1401b may support the sealing segment 1002 in case of any failure.

As discussed above, in some embodiments, the static seal segment 604 of each sealing segment 1002 may include the array of polygonal cells. In some embodiments, the static seal segment 604 of each sealing segment 1002 includes the honeycomb structure. Further, each sealing segment 1002 formed by ALM includes three-dimensional features, such as the flow control arm segment 1004, that may further improve of the functionality of the sealing systems 1000, 1050.

Figures 9A and 9B illustrate sectional views of sealing systems 1100 and 1150, respectively, according to embodiments of the present disclosure. The sealing systems 1100 and 1150 are substantially similar to the sealing systems 1000 and 1050, as shown in the Figures 8A and 8B, respectively. The rotating portions of the sealing systems 1100, 1150 are omitted in Figures 9A and 9B for the purpose of clarity.

In some embodiments, the sealing system 1100 includes the rear leg 416d and the rear flow control arm 416e of the sealing system 1000. However, the sealing system 1100 includes a plurality of sealing segments 1102 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 1102 from the plurality of sealing segments 1102 are coupled to each other. Each sealing segment 1102 is formed by ALM as one part. Each sealing segment 1102 includes the static seal segment 604, the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004. In addition, each sealing segment 1102 further includes a deflector segment 1104 extending from the flow control arm segment 1004 and inclined relative to the flow control arm segment 1004. In other words, the deflector segment 1104, the flow control arm segment 1004, the front leg segment 904, the backing plate segment 804 and the static seal segment 604 are integrally formed as the sealing segment 1102 which is a single integral part. The deflector segments 1104 of the plurality of the sealing segments 1102 are disposed adjacent to each other to together form a deflector having a circumferential extent of 360 degrees.

In some embodiments, the sealing system 1100 further includes the rear leg 416d and the rear flow control arm 416e similar to the sealing system 416, as shown in Figure 2.

In some embodiments, the rear leg 416d may be coupled to the plurality of sealing segments 1102. Specifically, the rear leg 416d is coupled to the backing plate segments 804 of the plurality of sealing segments 1102. In some embodiments, the rear leg 416d may be coupled to the backing plate segments 804 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

The sealing system 1150 is substantially similar to the sealing system 1100, as illustrated in Figure 9A. However, the sealing system 1150 includes the rear leg 502. In some embodiments, the rear leg 502 is also coupled to the plurality of sealing segments 1102. Specifically, the rear leg 502 is coupled to the front leg segments 904 of the plurality of sealing segments 1102. In some embodiments, the rear leg 502 may be coupled to the front leg segments 904 by one or more suitable attachment mechanisms, for example, mechanical fasteners, welding, tongue and groove connection, brazing, adhesives, and the like.

As discussed above, in some embodiments, the static seal segment 604 of each sealing segment 1102 may include the array of polygonal cells. In some embodiments, the static seal segment 604 of each sealing segment 1102 includes the honeycomb structure. Further, each sealing segment 1102 formed by ALM includes three-dimensional features, such as the deflector segment 1104, that may further improve of the functionality of the sealing systems 1100, 1150.

Figures 10A and 10B illustrate sectional views of sealing systems 1200 and 1250, respectively, according to embodiments of the present disclosure. The sealing systems 1200 and 1250 are substantially similar to the sealing systems 1100 and 1150, as shown in the Figures 9A and 9B, respectively. The rotating portions of the sealing systems 1200, 1250 are omitted in Figures 10A and 10B for the purpose of clarity.

In some embodiments, the sealing system 1200 includes a plurality of sealing segments 1202 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 1202 from the plurality of sealing segments 1202 are coupled to each other. Each sealing segment 1202 is formed by ALM as one part. Each sealing segment 1202 includes the static seal segment 604, the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004. In addition, each sealing segment 1202 further includes a rear leg segment 1204. In other words, the rear leg segment 1204, the flow control arm segment 1004, the front leg segment 904, the backing plate segment 804, and the static seal segment 604 are integrally formed as the sealing segment 1202 which is a single integral part. In some embodiments, each sealing segment 1202 may further include the deflector segment 1104. The rear leg segments 1204 are disposed adjacent to each other to together form a rear leg having a circumferential extent of 360 degrees.

The rear leg having the circumferential extent of 360 degrees formed by the rear leg segments 1204 disposed adjacent to each other may be substantially similar in shape and size of the rear leg 416d.

In some embodiments, each sealing segment 1202 may further include a rear flow control arm segment 1205. The rear flow control arm segments 1205 are disposed adjacent to each other to together form a rear flow control arm having a circumferential extent of 360 degrees. The rear flow control arm having the circumferential extent of 360 degrees formed by the rear flow control arm segments 1205 disposed adjacent to each other may be substantially similar in shape and size of the rear flow control arm 416e. The rear flow control arm segment 1205 extends at least axially from the rear leg segment 1204.

As discussed above, in some embodiments, the static seal segment 604 of each sealing segment 1202 may include the array of polygonal cells. In some embodiments, the static seal segment 604 of each sealing segment 1202 includes the honeycomb structure. Further, each sealing segment 1202 formed by ALM includes three-dimensional features, such as the deflector segment 1104, the rear leg segment 1204, and the rear flow control arm segment 1205, that may further improve of the functionality of the sealing system 1200.

The sealing system 1250 includes a plurality of sealing segments 1203 disposed adjacent to each other around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 1). The adjacent sealing segments 1203 from the plurality of sealing segments 1203 are coupled to each other. Each sealing segment 1203 is formed by ALM as one part. Each sealing segment 1203 includes the static seal segment 604, the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004. In addition, each sealing segment 1202 further includes a rear leg segment 1206. In other words, the rear leg segment 1206, the flow control arm segment 1004, the front leg segment 904, the backing plate segment 804, and the static seal segment 604 are integrally formed as the sealing segment 1203 which is a single integral part. In some embodiments, each sealing segment 1203 may further include the deflector segment 1104. The rear leg segments 1206 are disposed adjacent to each other to together form a rear leg having a circumferential extent of 360 degrees. The rear leg having the circumferential extent of 360 degrees formed by the rear leg segments 1206 disposed adjacent to each other may be substantially similar in shape and size of the rear leg 502.

In some embodiments, each sealing segment 1203 may further include the rear flow control arm segment 1205. The rear flow control arm segment 1205 extends at least axially from the rear leg segment 1206.

As discussed above, in some embodiments, the static seal segment 604 of each sealing 30 segment 1203 may include the array of polygonal cells. In some embodiments, the static seal segment 604 of each sealing segment 1203 includes the honeycomb structure. Further, each sealing segment 1203 formed by ALM includes three-dimensional features, such as the deflector segment 1104, the rear leg segment 1206, and the rear flow control arm segment 1205, that may further improve of the functionality of the sealing system 1250.

In some embodiments, the sealing systems 600, 650, 700, 750 800, 850, 900, 950 1000, 1050, 1100, 1150, 1200, 1250 (shown in Figures 4A-4B to 10A-10B), is disposed axially between the first rotor stage 404 and the second rotor stage 406 (shown in Figure 2). Specifically, the plurality of the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 shown in Figures 4A-4B to 10A-10B are disposed axially between the first rotor stage 404 and the second rotor stage 406. In some embodiments, a number of the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 required to be disposed adjacent to each other to have a circumferential extent of 360 degrees around the principal rotational axis 9 of the gas turbine engine 10 may range from about 12 to about 20. In some embodiments, the number of the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 may be based upon the gas turbine engine 10, and ALM machine capabilities.

Figure 11 illustrates a perspective view of the sealing segment 1002 of the sealing systems 1000, 1050 shown in Figures 8A and 83, respectively. In the illustrated embodiment of Figure 11, only one of the plurality of sealing segments 1002 is shown for illustrative purposes. Each sealing segment 1002 includes a first circumferential end 1301 and a second circumferential end 1303 opposite to the first circumferential end 1301. In some embodiments, each sealing segment 1002 includes a tab 1305 disposed at the first circumferential end 1301 and defining a first aperture 1305a therethrough. In some embodiments, each sealing segment 1002 includes a second aperture 1303a disposed proximal to the second circumferential end 1303.

In the illustrated embodiment of Figure 11, the sealing segment 1002 is shown as having the tab 1305, the first aperture 1305a, and the second aperture 1303a. However, in some other embodiments, each of the sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-7B and 9A-10B) may include the tab 1305, the first aperture 1305a, and the second aperture 1303a.

In the illustrated embodiment of Figure 11, the tab 1305 is disposed at least partially on the front leg segment 904. The tab 1305 is integrally formed with the sealing segment 1002 by ALM. In the illustrated embodiment of Figure 11, the front leg segment 904 of the sealing segment 1002 includes the second aperture 1303a. In some embodiments, each sealing segment 1002 further includes a third aperture 1307 circumferentially disposed between the first aperture 1305a and the second aperture 1303a. In the illustrated embodiment of Figure 11, the front leg segment 904 of the sealing segment 1002 includes the third aperture 1307. In some embodiments, the third aperture 1307 is configured to couple a corresponding sealing segment 1002 to the stator 408 (shown in Figure 2). Specifically, the third aperture 1307 is configured to couple the corresponding sealing segment 1002 to the platform 408a of the stator 408. In some embodiments, the third aperture 1307 is configured to couple the corresponding sealing segment 1002 to the vane inner rail 408b. In some embodiments, each of the first, second, and third apertures 1305a, 1303a, 1307 is configured to couple the corresponding sealing segment 1002 to the stator 408. Specifically, each of the first, second and third apertures 1305a, 1303a, 1307 is configured to couple the corresponding sealing segment 1002 to the platform 408a of the stator 408. In some embodiments, each of the first, second and third apertures 1305a, 1303a, 1307 is configured to couple the corresponding sealing segment 1002 to the vane inner rail 408b. The third aperture 1307 may provide a fail-safe coupling of the corresponding sealing segment 1002 to the stator 408.

In some embodiments, one or more of the first, second or third aperture 1205a, 1203a, and 1207 may receive respective fasteners to couple the front leg segment 904 to the stator 408 (shown in Figure 2). The fasteners may include, for example, nut and bolt assemblies, screws, rivets, and so forth. In some embodiments, the fasteners may include a HilockTM type fastener.

In some embodiments, a respective region around the second and third apertures 1303a, 1307 may have an additional thickness. The additional thickness may provide additional strength to the second and third apertures 1303a, 1307 upon coupling with the respective fasteners. In some embodiments, the respective region may act as a respective stiffener.

In some embodiments, each of the rear legs 416d, 502, 504 as shown in Figures 2, 3A- 3B to Figures 9A-9B, may also include apertures circumferentially spaced apart and corresponding to the first, second and third apertures 1305a, 1303a, and 1307 to couple the sealing segment 1002 to the respective rear legs 416d, 502, 504, the stator 408, and the front leg segment 904 with the help of the fasteners.

In some embodiments, the rear leg segments 1204, 1206, as shown in Figures 10A-10B, respectively, may also include apertures corresponding to the first, second and third aperture 1205a, 1203a, and 1207 to couple to the respective rear leg segments 1204, 1206, the stator 408, and the front leg segment 904 with the help of the fasteners.

Figures 12A and 12B illustrate perspective views of the sealing segment 1002 of the sealing systems 1000, 1050 shown in Figures 12A and 12B, according to another embodiment of the present disclosure. The sealing segment 1002 includes the first and second apertures 1305a, 1303a. In the illustrated embodiment of Figures 12A-12B, the sealing segment 1002 does not include the third aperture 1307. However, each sealing segment 1002 includes the first hook 1401a disposed proximal to the first circumferential end 1301 and the second hook 1401b disposed proximal to the second circumferential end 1303. In some embodiments, each of the first hook 1401a and the second hook 1401b is configured to couple a corresponding sealing segment 1002 to the stator 408 (shown in Figure 2). Specifically, each of the first hook 1401a and the second hook 1401b is configured to couple the corresponding sealing segment 1002 to the platform 408a of the stator 408. In some embodiments, each of the first hook 1401a and the second hook 1401b is configured to couple the corresponding sealing segment 1002 to the vane inner rail 408b. In some embodiments, each of the first hook 1401a and the second hook 1401b is configured to couple the corresponding sealing segment 1002 to the rear leg 416d, 502.

In some embodiments, the sealing segment 1002 includes at least one sealing protrusion 1403 (shown in Figure 12A) disposed at the first circumferential end 1301 and at least one sealing slot 1405 (shown in Figure 12B) disposed at the second circumferential end 1303.

In the illustrated embodiment of Figures 12A-12B, the sealing segment 1002 is shown having the at least one sealing protrusion 1403 and the at least one sealing slot 1405. However, in some other embodiments, each of the sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-7B and 9A-10B) may include the at least one sealing protrusion 1403 and the at least one sealing slot 1405.

In some embodiments, the sealing protrusion 1403 and the sealing slot 1405 engage with each other to form a strip seal between adjacent sealing segments 1002. In some other embodiments, the at least one sealing slot 1405 may be disposed at the first circumferential end 1301 and the at least one sealing protrusion 1403 may be disposed at the second circumferential end 1303.

In some embodiments, one or more of the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004 of the sealing segment 1002 may include the sealing protrusion 1403. Similarly, one or more of the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004 of the sealing segment 1002 may include the sealing slot 1405 corresponding to the one or more of the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004 of the sealing segment 1002 including the sealing protrusion 1403.

In the illustrated embodiments of Figures 12A-123, the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004 of the sealing segment 1002 include the sealing protrusion 1403 at the first circumferential end 1301. Similarly, the backing plate segment 804, the front leg segment 904, and the flow control arm segment 1004 of the sealing segment 1002 include the sealing slot 1405 at the second circumferential end 1303.

The at least one sealing protrusion 1403 and the at least one sealing slot 1405 of adjacent sealing segments 1002 may engage with each other to substantially prevent unintended leakages between the first rotor stage 404 and the second rotor stage 406.

In some other embodiments, an additional seal (not shown) may be provided between 20 the adjacent sealing segments 1002. The additional seal may include, but not limited to, strip seals, spline seals and the like. In some embodiments, the additional seal may also be formed by ALM.

Figures 13A and 13B illustrate a first adjacent sealing segment 1002-1, a second adjacent sealing segment 1002-3, and an intermediate sealing segment 1002-2 disposed between the first adjacent sealing segment 1002-1 and the second adjacent sealing segment 1002-3.

Figure 13A illustrates the first adjacent sealing segment 1002-1, the second adjacent sealing segment 1002-3, and the intermediate sealing segment 1002-2 in an unassembled state. Figure 13B illustrates the first adjacent sealing segment 1002-1, the second adjacent sealing segment 1002-3, and the intermediate sealing segment 1002-2 in an assembled state.

In the illustrated embodiment of Figures 13A-13B, each of the first adjacent sealing segment 1002-1, the second adjacent sealing segment 1002-3, and the intermediate sealing segment 1002-2 are adjacent sealing segments of the plurality of sealing segments 1002. However, the adjacent sealing segments of the plurality of sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-7B and 9A-10B) may be similarly arranged.

Referring to Figures 13A-13B, in some embodiments, the first circumferential end 1301 of the intermediate sealing segment 1002-2 is disposed adjacent to the second circumferential end 1303 of the first adjacent sealing segment 1002-1 and the second circumferential end 1303 of the intermediate sealing segment 1002-2 is disposed adjacent to the first circumferential end 1301 of the second adjacent sealing segment 1002-3.

In some embodiments, the first aperture 1305a of the intermediate sealing segment 1002-2 is aligned with the second aperture 1303a of the first adjacent sealing segment 1002-1 for coupling the intermediate sealing segment 1002-2 to the first adjacent sealing segment 1002-1. In some embodiments, the second aperture 1303a of the intermediate sealing segment 1002-2 is aligned with the first aperture 1305a of the second adjacent sealing segment 1002-3 for coupling the intermediate sealing segment 1002-2 to the second adjacent sealing segment 1002-3.

In some embodiments, after aligning the first aperture 1305a of the intermediate sealing segment 1002-2 with the second aperture 1303a of the first adjacent sealing segment 1002-1, the intermediate sealing segment 1002-2 is coupled to the first adjacent sealing segment 1002-1 using one or more fasteners 1501. In some embodiments, after aligning the second aperture 1303a of the intermediate sealing segment 1002-2 with the first aperture 1305a of the second adjacent sealing segment 1002-3, the intermediate sealing segment 1002-2 is coupled to the second adjacent sealing segment 1002-3 using the fasteners 1501.

In some embodiments, the fasteners 1501 may be similar to the fastener 508 (shown in Figure 3B). In some embodiments, the fasteners 1501 may be different from the fastener 508. The fasteners 1501 may include, for example, nut and bolt assemblies, screws, rivets, and so forth.

In some embodiments, the adjacent sealing segments 1002 define a circumferential gap Gc therebetween. For example, the intermediate sealing segment 1002-2 and the second adjacent sealing segment 1002-3 may form the circumferential gap Gc between the intermediate sealing segment 1002-2 and the second adjacent sealing segment 1002-3. The circumferential gap Gc may cause leakages between the first rotor stage 404 and the second rotor stage 406. In some embodiments, the leakage is substantially reduced with the help of the at least one sealing protrusion 1403 and the at least one sealing slot 1405 (shown in Figures 12A-12B). Specifically, the at least one sealing protrusion 1403 of the intermediate sealing segment 1002-2 is at least partially received in the at least sealing slot 1405 of the first adjacent sealing segment 1002-1. Similarly, the at least one sealing slot 1405 of the intermediate sealing segment 1002-2 is at least partially received the at least sealing protrusion 1403 of the second adjacent sealing segment 1002-3. This engagement of the first adjacent sealing segment 1002-1, the intermediate sealing segment 1002-2, and the second adjacent sealing segment 1002-3 may form a labyrinth seal with low radial and/or axial gaps and consequently reduce the leakages between the first rotor stage 404 and the second rotor stage 406.

In some other embodiments, the additional seals may be provided between two of the plurality of the sealing segments 1002 to substantially reduce the circumferential gap Gc by forming a labyrinth seal.

Similarly, the adjacent sealing segments of the plurality of sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-73 and 9A-10B) may define the circumferential gap Gc therebetween.

Figures 14A-14C illustrate schematic top views of the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2, according to other embodiments of the present disclosure. In some embodiments, each sealing segment (for example, the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2) includes a first interface surface IF disposed at the first circumferential end 1301 and a second interface surface Is disposed at the second circumferential end 1303. In some other embodiments, each sealing segment (for example, the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2) includes the first interface surface IF disposed at the second circumferential end 1303 and the second interface surface Is disposed at the first circumferential end 1301.

In the assembled state, the first interface surface IF of the intermediate sealing segment 1002-2 abuts with the second interface surface Is of the first adjacent sealing segment 1002-1.

In the illustrated embodiment of Figure 14A, each of the first interface surface IF and the 5 second interface surface Is includes a planar surface Ps inclined obliquely relative to the circumferential direction C. In the assembled state, the first interface surface IF of the intermediate sealing segment 1002-2 abuts with the second interface surface!sof the first adjacent sealing segment 1002-1. Each of the first interface surface IF and the second interface surface Is including the planar surface Ps may be easily formed by ALM. The planar surface Ps inclined obliquely relative to the circumferential direction C may provide a higher axial stiffness to each of the intermediate sealing segment 1002-2 and the first adjacent sealing segment 1002-1.

In the illustrated embodiment of Figure 14A, the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2 are shown having the planar surfaces Ps inclined obliquely relative to the circumferential direction C. However, in some other embodiments, each of the plurality of sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-7B and 9A-10B) may include the planar surfaces Ps inclined obliquely relative to the circumferential direction C. Figure 14B illustrates another embodiment of the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2. In this embodiment, each of the first interface surface IF and the second interface surface Is includes a plurality of planar surfaces PI inclined relative to each other, and each planar surface PI is inclined obliquely relative to the circumferential direction C. The plurality of planar surfaces PI inclined relative to each other may help in locating and interlocking the adjacent sealing segments (for example, the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2). In the assembled state, the first interface surface IF of the intermediate sealing segment 1002-2 interlocks with the second interface surface Is of the first adjacent sealing segment 1002-1. Further, the plurality of planar surfaces PI inclined or not obliquely relative to the circumferential direction C may also provide a higher axial stiffness to each of the intermediate sealing segment 1002-2 and the first adjacent sealing segment 1002-1. Each of the first interface surface IF and the second interface surface Is including the plurality of planar surfaces PI may be easily formed by ALM.

In the illustrated embodiment of Figure 14B, the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2 are shown having the plurality of planar surfaces P, inclined relative to each other. However, in some other embodiments, each of the plurality of sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-7B and 9A-10B) may include the plurality of planar surfaces P, inclined relative to each other.

Figure 14C illustrates another embodiment of the first adjacent sealing segment 1002-1 and the intermediate sealing segment 1002-2. In this embodiment, the planar surface Ps is not inclined obliquely relative to the circumferential direction C. Specifically, the planar surface Ps is perpendicular to the circumferential direction C. In the assembled state, the first interface surface IF of the intermediate sealing segment 1002-2 abuts with the second interface surface Is of the first adjacent sealing segment 1002-1.

Figure 15 illustrates a partial schematic view of the stator 408. The plurality of sealing segments 1002 are disposed adjacent to each other circumferentially. Specifically, the sealing segments 1002 are disposed adjacent to each other along the circumferential direction C. The stator 408 along with the sealing segments 1002 have a circumferential extent of 360 degrees around the principal rotational axis 9 of the gas turbine engine 10 (shown in Figure 2). Each of the plurality of sealing segments 1002 is coupled to the platform 408a of the stator 408. Specifically, each of the plurality of sealing segments 1002 is coupled to the vane inner rail 408b (shown in Figure 2). In the illustrated embodiment of Figure 15, the plurality of sealing segments 1002 is shown coupled to the platform 408a of the stator 408. Specifically, the plurality of sealing segments 1002 are shown coupled to the vane inner rail 408b. However, in some other embodiments, the plurality of sealing segments 602, 702, 802, 902, 1102, 1202, 1203 (shown in Figures 4A-7B and 9A-10B) may be coupled to the platform 408a of the stator 408. The plurality of sealing segments 1002 are disposed axially between the first rotor stage 404 and the second rotor stage 406 (shown in Figure 2).

The overall size and shape of the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 may be varied conveniently using ALM as per application requirements.

Further, materials used for forming the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 may be varied conveniently using ALM. For example, the material may include one or more of: steel and its alloys, aluminium and its alloys, titanium and its alloys, nickel and its alloys, copper and its alloys, polymers, metal coated polymers, and composite materials. Furthermore, the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 may be built from a model file. Further, the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 may be adapted to suit applications having varying size, shape, weight, and stiffness requirements. In some embodiments, the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 may be manufactured using ALM to suit individual requirements based on characteristics derived from computer simulations.

Moreover, forming the plurality of sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 instead of a single piece sealing segment may make the fabrication and/or optimization of the sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 by ALM easier. Further, including the plurality of sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 instead of the single piece sealing segment may further reduce the cost of repairs.

Further, forming the plurality of sealing segments 602, 702, 802, 902, 1002, 1102, 1202, 1203 by ALM may enable adding three-dimensional features, such as the front leg segment 904, the flow control arm segment 1004, the deflector segment 1104, the rear leg segment 1204, the rear leg segment 1206 in the plurality of sealing segments 902, 1002, 1102, 1202, 1203. Integrating the three-dimensional features in each sealing segment may further reduce the cost of manufacturing and repairs.

It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

Claims

CLAIMS1. A sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) for a gas turbine engine (10) having a principal rotational axis (9), the 5 sealing system (600, 650, 700, 750 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) comprising: a plurality of sealing segments (602, 702, 802, 902, 1002, 1102; 1202, 1203) disposed adjacent to each other around the principal rotational axis (9) of the gas turbine engine (10), wherein adjacent sealing segments (602, 702, 802, 902, 1002, 1102, 1202, 1203) from the plurality of sealing segments (602, 702, 802, 902, 1002, 1102, 1202, 1203) are coupled to each other, wherein each sealing segment (602, 702, 802, 902, 1002, 1102, 1202, 1203) is formed by Additive Layer Manufacturing (ALM) as one part and comprises a static seal segment (604), and wherein the static seal segments (604) of the plurality of the sealing segments (602, 702, 802, 902, 1002, 1102, 1202, 1203) are disposed adjacent to each other to together form a static seal member (416a) having a circumferential extent of 360 degrees; and a rotating seal member (412) disposed radially inwards of the static seal member (416a), such that an annular seal (417) is formed between the rotating seal member (412) and the static seal member (416a).
2. The sealing system (600, 650, 700, 750) of claim 1, further comprising: a backing plate (416b) disposed adjacent to the static seal member (416a), the backing plate (416b) comprising a first surface (SF) facing the static seal segments (604) and a second surface (Ss) opposite to the first surface (SF); a front leg (416c) extending at least radially outwards from the second surface 25 (Ss) of the backing plate (416b); and a rear leg (416d, 502) axially spaced apart from the front leg (416c) and extending radially with respect to the backing plate (416b).
3. The sealing system (800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of claim 2, wherein each sealing segment (802, 902, 1002, 1102, 1202, 1203) further comprises a backing plate segment (804), and wherein the backing plate segments (804) of the plurality of the sealing segments (802, 902, 1002, 1102, 1202, 1203) are disposed adjacent to each other to together form the backing plate (416b).
4. The sealing system (700, 750) of claim 2, wherein each sealing segment (702) further comprises an intermediate plate (704) disposed between the backing plate (416b) and the static seal segment (604).
5. The sealing system (600, 650, 700, 750) of claim 2 or 4, wherein the backing 10 plate (416b) is a single integral part coupled to the plurality of sealing segments (602, 702).
6. The sealing system (900, 950 1000, 1050, 1100, 1150, 1200, 1250) of any one of claims 2 to 5, wherein each sealing segment (902, 1002, 1102, 1202, 1203) further comprises a front leg segment (904), wherein the front leg segments (904) of the plurality of the sealing segments (902, 1002, 1102, 1202, 1203) are disposed adjacent to each other to together form the front leg (416c).
7. The sealing system (600, 650, 700, 750, 800, 850) of any one of claims 2 to 5, wherein the front leg (416c) is a single integral part coupled to the backing plate (416b).
8. The sealing system (600, 650, 700, 750, 800, 850, 900, 950) of any one of 20 claims 2 to 7, further comprising a flow control arm (4161) extending at least axially from the front leg (416c).
9. The sealing system (1000, 1050, 1100, 1150, 1200, 1250) of claim 8, wherein each sealing segment (1002, 1102, 1202, 1203) further comprises a flow control arm segment (1004), and wherein the flow control arm segments (1004) of the plurality of the sealing segments (1002, 1102, 1202, 1203) are disposed adjacent to each other to together form the flow control arm (4160.
10. The sealing system (600, 650, 700, 750, 800, 850, 900, 950) of claim 8, wherein the flow control arm (4161) is a single integral part coupled to the front leg (416c).
11. The sealing system (1100, 1150, 1200, 1250) of claim 9, wherein each sealing 30 segment (1102, 1202, 1203) further comprises a deflector segment (1104) extending from the flow control arm segment (1004) and inclined relative to the flow control arm segment (1004), and wherein the deflector segments (1104) of the plurality of the sealing segments (1102, 1202, 1203) are disposed adjacent to each other to together form a deflector.
12. The sealing system (1200, 1250) of any one of claims 2 to 11, wherein each sealing segment (1202, 1203) further comprises a rear leg segment (1204, 1206), and wherein the rear leg segments (1204, 1206) of the plurality of the sealing segments (1202, 1203) are disposed adjacent to each other to together form the rear leg (416d, 502).
13. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of any one of the preceding claims, wherein each sealing segment (602, 702, 802, 902, 1002, 1102, 1202, 1203) further comprises: a first circumferential end (1301) and a second circumferential end (1303) opposite to the first circumferential end (1301); a tab (1305) disposed at the first circumferential end (1301) and defining a first aperture (1305a) therethrough; and a second aperture (1303a) disposed proximal to the second circumferential end (1303)
14. The sealing system (900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of claim 13, wherein each sealing segment (902, 1002, 1102, 1202, 1203) further comprises a third aperture (1307) circumferentially disposed between the first aperture (1305a) and the second aperture (1303a), wherein the third aperture (1307) is configured to couple a corresponding sealing segment (902, 1002, 1102, 1202, 1203) to a stator (408).
15. The sealing system (900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of claim 13, wherein each sealing segment (902, 1002, 1102, 1202, 1203) further comprises a first hook (1401a) disposed proximal to the first circumferential end (1301) and a second hook (1401b) disposed proximal to the second circumferential end (1303), and wherein each of the first hook (1401a) and the second hook (1401b) is configured to couple a corresponding sealing segment (902, 1002, 1102, 1202, 1203) to at least one of a stator (408) and the rear leg (416d, 502).
16. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of any one of claims 13 to 15, wherein each sealing segment (602, 702, 802, 902, 1002, 1102, 1202, 1203) further comprises at least one sealing protrusion (1403) disposed at the first circumferential end (1301) and at least one sealing slot (1405) disposed at the second circumferential end (1303).
17. The sealing system (600, 650, 700, 750, 800, 850,900, 1000, 1050, 1100, 1150, 1200, 1250) of claim 16, wherein, for an intermediate sealing segment (1002-2) disposed between a first adjacent sealing segment (1002-1) and a second adjacent sealing segment (1002-3), the first circumferential end (1301) of the intermediate sealing segment (1002-2) is disposed adjacent to the second circumferential end (1303) of the first adjacent sealing segment (1002-1) and the second circumferential end (1303) of the intermediate sealing segment (1002-2) is disposed adjacent to the first circumferential end (1301) of the second adjacent sealing segment (1002-3), and wherein: the first aperture (1305a) of the intermediate sealing segment (1002-2) is aligned with the second aperture (1303a) of the first adjacent sealing segment (1002-1) for coupling the intermediate sealing segment (1002-2) to the first adjacent sealing segment (1002-1); the second aperture (1303a) of the intermediate sealing segment (1002-2) is 20 aligned with the first aperture (1305a) of the second adjacent sealing segment (1002-3) for coupling the intermediate sealing segment (1002-2) to the second adjacent sealing segment (1002-3); the at least one sealing protrusion (1403) of the intermediate sealing segment (1002-2) is at least partially received in the at least sealing slot (1405) of the first 25 adjacent sealing segment (1002-1); and the at least one sealing slot (1405) of the intermediate sealing segment (1002-2) at least partially receives the at least sealing protrusion (1403) of the second adjacent sealing segment (1002-3).
18. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 30 1150, 1200, 1250) of any one of claims 13 to 17, each sealing segment (602, 702, 802, 902, 1002, 1102, 1202, 1203) further comprises a first interface surface (IF) disposed at the first circumferential end (1301) and a second interface surface (la) disposed at the second circumferential end (1303).
19. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of claim 18, wherein each of the first interface surface (IF) and the 5 second interface surface (la) comprises a planar surface (Ps) inclined obliquely or perpendicular relative to a circumferential direction (C).
20. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of claim 18, wherein each of the first interface surface (IF) and the second interface surface (la) comprises a plurality of the planar surfaces (P1) inclined relative to each other, and wherein each planar surface (P1) is inclined obliquely or perpendicular relative to a circumferential direction (C).
21. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of any one of the preceding claims, wherein the static seal segment (604) of each sealing segment (602, 702, 802, 902, 1002, 1102, 1202, 1203) comprises 15 a honeycomb structure.
22. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of any one of the preceding claims, wherein the rotating seal member (412) comprises a plurality of fins (412a) extending towards the static seal member (416a).
23. The sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of any one of the preceding claims, wherein the adjacent sealing segments (602, 702, 802, 902, 1002, 1102, 1202, 1203) define a circumferential gap (Gc) therebetween.
24. A gas turbine engine (10), comprising: a rotor disc (402) configured to rotate about a principal rotational axis (9); a first rotor stage (404) comprising an annular array of first rotor blades (405) extending from the rotor disc (402); a second rotor stage (406) comprising an annular array of second rotor blades (407) extending from the rotor disc (402) and disposed downstream of the first rotor blades (405); a stator (408) disposed axially between the first rotor stage (404) and the second 5 rotor stage (406), the stator (408) comprising a platform (408a) and an annular array of stator vanes (409) extending from the platform (408a); the sealing system (600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250) of any one of the preceding claims, wherein the plurality of sealing segments (602, 702, 802, 902, 1002, 1102, 1202, 1203) and the rotating seal member (412) are disposed axially between the first rotor stage (404) and the second rotor stage (406).
25. The gas turbine engine (10) of claim 24, wherein each of the plurality of sealing segments (602, 702, 802, 902, 1002, 1102, 1202, 1203) is coupled to the platform (408a) of the stator (408).