The present disclosure relates generally to gas turbine engines, and more specifically to sealing features for use in gas turbine engines.
Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Compressors and turbines typically include alternating stages of static vane assemblies and rotating wheel assemblies. Fluid leakage between stages reduces overall gas turbine engine performance and efficiency. As such, some turbine sections include inner seals to reduce such leakage. The inner seals may be coupled to the vane assembly or may engage abradable material coupled to the vane assembly.
However, in ceramic matrix composite vane embodiments, coupling the inner seal to the vane assembly may increase structural loads on the ceramic matrix composite material. Additionally, the vane assembly may use additional seals due to the difference in coefficients of thermal expansion between the metallic materials of the supporting structure and the ceramic materials of the vane. As such, sealing features remain an area of interest for ceramic matrix composite components.
The present disclosure may comprise one or more of the following features and combinations thereof.
A turbine assembly for use with a gas turbine engine may include a bladed wheel assembly, a vane assembly, and an inner seal. The bladed wheel assembly may be adapted to interact with gases flowing through a gas path of the gas turbine engine. The gases may push the bladed wheel assembly to rotate about an axis during use of the turbine assembly. The vane assembly may be located upstream of the bladed wheel assembly and adapted to direct the gases at the bladed wheel assembly. The inner seal may engage the vane assembly and may be coupled with the bladed wheel assembly for rotation therewith about the axis to block gases from passing between the inner seal and the vane assembly during use of the turbine assembly.
In some embodiments, the bladed wheel assembly may include a disk and a plurality of blades. The disk may be arranged around the axis. The plurality of blades may extend radially from the disk,
In some embodiments, the vane assembly may include a vane and an inner support. In some embodiments, the inner support may be located radially inward of the vane and may be coupled with the vane. In some embodiments, the vane assembly may be fixed relative to the axis.
In some embodiments, the vane may include an outer platform, an inner platform, and an airfoil. The inner platform may be spaced apart radially from the outer platform relative to an axis. The airfoil may extend radially between the outer platform and the inner platform. In some embodiments, the inner support may be located radially inward of the inner platform and may be coupled with the vane.
In some embodiments, the inner seal may include a radially and circumferentially extending seal body, a rub band, and a mount ring. The seal body may be fastened with the disk for rotation with the disk. The rub band may be coupled to a radial outer end of the seal body. In some embodiments, the rub band may be engage with the inner support to seal between the rub band and the inner support. The mount ring may extend axially aft and radially inward from the rub band.
In some embodiments, the mount ring may be interlocked with the disk to form a bayonet fitting with the disk. The bayonet fitting may block axial movement of the mount ring away from the disk. The bayonet fitting may also transmit a portion of the force loads caused by rotation of the inner seal to the disk to reduce a magnitude of the force loads carried by the seal body.
In some embodiments, the disk may include a disk body and an outer flange. The disk body may be arranged circumferentially around the axis. The outer flange may extend axially forward from the disk body to define a radially outward opening channel.
In some embodiments, the mount ring may extend radially inward into the channel. In some embodiments, the mount ring may be configured to engage the outer flange so that axial movement of the mount ring is blocked by the outer flange.
In some embodiments, the outer flange may be castellated to define a plurality of disk grooves. The plurality of disk grooves may extend radially inward into the outer flange.
In some embodiments, the mount ring may be castellated to define a plurality of grooves. The plurality of grooves may extend radially outward into the mount ring.
In some embodiments, the disk includes an inner flange. The inner flange may be located radially inward of the outer flange. In some embodiments, the inner flange may extend axially forward from the disk body, and the seal body may be fastened with the inner flange for movement with the inner flange.
In some embodiments, the disk may include a radially inwardly facing shoulder. The radially inwardly facing shoulder may be located radially outward of the outer flange.
In some embodiments, the mount ring may include a radially outward facing shoulder. The radially outwardly facing shoulder may engage the radially inward facing shoulder of the disk to transmit the portion of the force loads in the radial direction.
In some embodiments, the rub band may include a hoop and a plurality of fins. The hoop may extend circumferentially around the axis and axially aft of the seal body. The plurality of fins may extend radially outward from the hoop. In some embodiments, the hoop may interconnect the seal body and the mount ring.
In some embodiments, the inner platform and the inner support may be integrally formed as a single, one-piece component. The integrally formed one-piece component may be separate from the outer platform and the airfoil.
In some embodiments, the rub band may include a hoop, a plurality of forward fins, and a plurality of aft fins. The plurality of forward fins may extend radially outward from the hoop. The plurality of aft fins may extend radially outward from the hoop.
In some embodiments, the hoop may extend circumferentially around the axis and may be coupled with a radial terminal end of the seal body. The plurality of aft fins may be spaced apart axially from the plurality of forward fins to define an annular chamber therebetween.
In some embodiments, the hoop may be formed to define a hole. The hole may extend radially through the hoop and may open into the annular chamber.
In some embodiments, the inner support may be a full hoop and may be formed to define passageways. The passageways may each extend radially inward into the inner support and turn axially aft and open into an aft facing surface of the inner support. The passageways may cause the inner support to act as a pre-swirl nozzle configured to deliver pressurized air to the disk.
According to another aspect of the present disclosure, a turbine assembly for use with a gas turbine engine may include a first bladed wheel assembly, a vane assembly, and an inner seal. The first bladed wheel assembly may include a disk arranged around an axis and a plurality of blades that extend radially from the disk. The vane assembly may include a vane and an inner support located radially inward of the vane and coupled with the vane.
In some embodiments, the inner seal may include a seal body, a rub band, and a mount ring. The seal body may extend circumferentially about the axis. The rub band may extend axially away from a radial outer end of the seal body. The mount ring may extend radially inward from the rub band. In some embodiments, the rub band may extend only in a single axial direction away from the radial outer end of the seal body.
In some embodiments, the seal body may be coupled with the disk of the first bladed wheel assembly. The mount ring may interlock with the disk so that the mount ring is blocked from moving axially away from the disk of the first bladed wheel assembly.
In some embodiments, the turbine assembly may further include a second bladed wheel assembly. The second bladed wheel assembly may be spaced apart axially from the first bladed wheel assembly to locate the inner seal between the first and second bladed wheel assemblies. In some embodiments, only the seal body may engage the second bladed wheel assembly.
In some embodiments, the mount ring may include a lip and a plurality of tabs. The plurality of tabs may extend radially inward from the lip.
In some embodiments, the disk may be formed to include a flange. The flange may have an arm and a plurality of tabs. The plurality of tabs may extend from the arm. In some embodiments, the plurality of tabs of the mount ring may be aligned with the plurality of tabs of the flange to interlock the inner seal with the disk.
In some embodiments, the disk may be formed to include a first plurality of fastener holes. The first plurality of fastener holes may be arranged circumferentially around the axis.
In some embodiments, the seal body may be formed to include a second plurality of fastener holes. The second plurality of fastener holes may be arranged circumferentially around the axis. In some embodiments, the plurality of tabs of the mount ring may be aligned with the plurality of tabs of the flange in response to the fastener holes formed in the seal body being aligned with the fastener holes formed in the disk.
In some embodiments, the rub band may include a hoop, a forward fin, and an aft fin. The forward fin may extend radially away from the hoop and engage the vane assembly. The aft fin may extend radially away from the hoop and engage the vane assembly.
In some embodiments, the hoop may be formed to define a plurality of holes. The plurality of holes may extend radially through the hoop between the forward fin and the aft fin.
In some embodiments, the vane assembly may include an outer platform, an airfoil, and an inner support. The airfoil may extend radially inward from the outer platform.
In some embodiments, the inner support may include an inner platform and an inner carrier. The inner carrier may be located radially inward of the inner platform.
According to another aspect of the present disclosure, a method may include several steps. The method may include providing a bladed wheel assembly, a vane assembly, and an inner seal. The bladed wheel assembly may be arranged around an axis.
In some embodiments, method may further include locating the vane assembly axially adjacent the bladed wheel assembly, aligning the inner seal with the disk along the axis, translating axially the inner seal relative to the disk to cause the inner seal to align axially with and engage the vane assembly, rotating the inner seal relative to the disk partway about the axis to cause the inner seal to interlock with the disk after the translating step, and fixing the inner seal with the disk for rotational movement with the disk after the rotating step. In some embodiments, the fixing step may include inserting fasteners into the inner seal and the bladed wheel assembly so that that inner seal is blocked from rotating relative to the bladed wheel assembly.
In some embodiments, the vane assembly may include a vane and a pre-swirl nozzle. The pre-swirl nozzle may be coupled to a radial inner end of the vane. In some embodiments, the method may further include engaging the inner seal with the pre-swirler and directing pressurized air radially through the vane, through the pre-swirler, and axially toward the disk via an outlet of the pre-swirler.
In some embodiments, the inner seal may include a seal body, a rub band, and a mount ring. The seal body may extend circumferentially about the axis. The rub band may extend axially away from a radial outer end of the seal body. The mount ring may extend radially inward from the rub band.
In some embodiments, the rub band may include a hoop, a forward fin, and an aft fin. The forward fin may extend radially away from the hoop and engage the vane assembly. The aft fin may extend radially away from the hoop and engage the vane assembly.
In some embodiments, the hoop may be formed to define a plurality of holes. The holes may extend radially through the hoop between the forward fin and the aft fin.
These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.
For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.
A turbine assembly 18 for use with a gas turbine engine 10 is shown in
The inner seal 26 includes a radially and circumferentially extending seal body 30, a rub band 32, and a mount ring 34 as shown in
In the illustrative embodiment, the mount ring 34 is interlocked with the disk 38 to form a bayonet fitting 42 with the disk 38 as shown in
In some gas turbine engines, an inner seal may be coupled to a metallic support that couples a vane assembly to an associated turbine case to seal between the adjacent vane assembly and the bladed wheel assembly. In such embodiments, the vane assembly may include several seals to seal between the plurality of joints between the different components. Effectively sealing the plurality of joints may be difficult in cases where the joints are between a metallic component and a ceramic matrix composite component due to coefficient of thermal expansion mismatch between the two materials. The inner seal 26 of the present disclosure is separately supported from the vane assembly 24 and therefore reduces the number of metal to ceramic joints in the assembly, improving overall sealing and engine performance.
The turbine assembly 18 is adapted for use in the gas turbine engine 10, which includes a fan 12, a compressor 14, a combustor 16, and the turbine assembly 18 as shown in
The bladed wheel assembly 22 includes the disk 38 and a plurality of blades 40. The disk 38 is arranged around the axis 11. The plurality of blades 40 are coupled with and extend radially from the disk 38. The disk 38 includes a disk body 44, an outer flange 46, and an inner flange 48 as shown in
In the illustrative embodiment, the mount ring 34 extends radially inward into the channel 50 as shown in
In the illustrative embodiment, the outer flange 46 is castellated to define a plurality of disk grooves 52, and the mount ring 34 is castellated to define a plurality of ring grooves 54 as shown in
In the illustrative embodiment, the disk tabs 53 are sized to fit into the ring grooves 54, while the ring tabs 55 are sized to fit into the disk grooves 52 such that the together the tabs 53, 55 so that the mount ring 34 may be coupled to the disk 38 and form the bayonet fitting 42. Once assembled, the disk tabs 53 and the ring tabs 55 engage one another to couple the mount ring 34 and the disk 38 together and block axial movement of the mount ring 34.
In the illustrative embodiment, the disk 38 further includes a radially inwardly facing shoulder 56 as shown in
The rub band 32 includes a hoop 60 and a plurality of fins 62 as shown in
Turning again to the vane assembly 24, the vane assembly 24 includes a vane 66, an outer support 68, and an inner support 70 as shown in
The vane 66 includes an outer platform 74, an inner platform 76, and an airfoil 78 as shown in
The inner support 70 includes an inner carrier 80 and an abradable band 82 as shown in
In the illustrative embodiment, the abradable band 82 is segmented as shown in
In the illustrative embodiment, the seal body 30 is formed to include a plurality of fastener holes 83 arranged circumferentially around the axis 11 as shown in
A method of assembling and using the turbine assembly 18 may include several steps. The method includes locating the vane assembly 24 axially adjacent to the bladed wheel assembly 22 and aligning the inner seal 26 with the disk 38 along the axis 11. The aligning step includes lining up the disk grooves 52 with the ring tabs 55 of the mount ring 34 and the ring grooves 54 with the disk tabs 53 of the outer flange 46.
Once, the inner seal 26 is aligned with the disk 38, the method continues by translating the inner seal 26 axially relative to the disk 38 to cause the inner seal 26 to align axially with and engage the vane assembly 24. The translating step causes the tabs 53 to move through the ring grooves 54 and the tabs 55 through the disk grooves 52 so that the mount ring 34 is located in the channel 50.
After the translating step, the method further includes rotating the inner seal 26 relative to the disk 38 partway about the axis 11 to cause the inner seal 26 to interlock with the disk 38. The rotating step causes the disk tabs 53 to engage the ring tabs 55 and block axial movement of the inner seal 26. Then, the inner seal 26 is fixed with the disk 38 for rotational movement with the disk 38. In the illustrative embodiment, the fixing step includes inserting fasteners 81 into the inner seal 26 and the bladed wheel assembly 22 so that that inner seal 26 is blocked from rotating relative to the bladed wheel assembly 22.
Another embodiment of a turbine assembly 218 in accordance with the present disclosure is shown in
The turbine assembly 218 includes a bladed wheel assembly 222, a vane assembly 224, and an inner seal 226 as shown in
The vane assembly 224 includes a vane 266, an outer support 268, and an inner support 270 as shown in
The vane 266 includes an outer platform (not shown) and an airfoil 278 as shown in
The inner support 270 includes an inner platform 276, an inner carrier 280, and an abradable band 282 as shown in
In the illustrative embodiment, inner platform 276 and the inner support 270 are integrally formed as a single, one-piece component that is separate from the outer platform and the airfoil 278. The portion of the airfoil 278 received in the inner support 270 extends radially into the one-piece component such that the inner platform 276 comprising metallic materials forms the inner platform 276 of the vane 266.
Another embodiment of a turbine assembly 318 in accordance with the present disclosure is shown in
The turbine assembly 318 includes a bladed wheel assembly 322, a vane assembly 324, and an inner seal 326 as shown in
The vane assembly 324 includes a vane 366 and an inner support 370 as shown in
The inner seal 326 includes a radially and circumferentially extending seal body 330, a rub band 332, and a mount ring 334 as shown in
In the illustrative embodiment, the mount ring 334 is interlocked with the disk 338 to form a bayonet fitting 342 with the disk 338 as shown in
The rub band 332 includes a hoop 360 and a plurality of fins 362, 364 as shown in
In the illustrative embodiment, the plurality of fins 362, 364 includes a forward fin 362 and an aft fin 364 as shown in
In the illustrative embodiment, the hoop 360 is formed to define a plurality of holes 388 as shown in
The mount ring 334 includes a plurality of ring grooves 352, a radially outward facing shoulder 358, and a plurality of holes 390 as shown in
The inner support 370 includes an inner carrier 380, a first abradable band 382, and a second abradable band 386 as shown in
Another embodiment of a turbine assembly 418 in accordance with the present disclosure is shown in
The turbine assembly 418 includes a bladed wheel assembly 422, a vane assembly 424, and an inner seal 426 as shown in
The vane assembly 424 includes a vane 466, an outer support 468, an inner support 470, and a pre-swirl nozzle 472 as shown in
The inner support 470 that includes an inner platform 476 and an inner carrier 480 as shown in
The pre-swirl nozzle 472 includes a body 492 and a spout 494 as shown in
The inner seal 426 includes a seal body 430, a rub band 432, and a mount ring 434 as shown in
The rub band 432 includes a hoop 460 and a plurality of fins 462, 464 as shown in
In the illustrative embodiment, the vane assembly 424 further includes an abradable band 482 as shown in
The mount ring 434 includes a plurality of ring grooves 454, a radially outward facing shoulder 458, and a plurality of holes 490 as shown in
In the illustrative embodiment, the inner seal 426 further includes a knife seal 496 as shown in
In the illustrative embodiment, the vane assembly 424 further includes a second abradable band 484 as shown in
Another embodiment of a turbine assembly 518 in accordance with the present disclosure is shown in
The turbine assembly 518 includes a bladed wheel assembly 520, a vane assembly 524, and an inner seal 526 as shown in
The inner seal 526 includes a seal body 530, a rub band 532, and a mount ring 534 as shown in
The radial outer end 536 of the seal body 530 includes an axially extending lip 591 and a radially extending flange 593 as shown in
The rub band 532 includes a hoop 560, a lip 561, and a plurality of fins 562 as shown in
In the illustrative embodiment, the lip 561 includes a radially inwardly extending portion 595 and an axially extending portion 597 as shown in
In some embodiments, the inner seal 526 may include an anti-rotation feature (not shown). The anti-rotation feature may be configured to block circumferential movement of the rub band 532 about the axis 11 relative to seal body 530. The anti-rotation feature may extend radially through the lip 591 and the axially extending portion 595 to block circumferential movement of the rub band 532 relative to the seal body 530.
Another embodiment of a turbine assembly 618 in accordance with the present disclosure is shown in
The turbine assembly 618 includes a bladed wheel assembly 620, a vane assembly 624, and an inner seal 626 as shown in
The inner seal 626 includes a seal body 630, a rub band 632, and a mount ring 634 as shown in
The radial outer end 636 of the seal body 630 is shaped to include an attachment channel 691 as shown in
The rub band 632 includes a hoop 660, a root 661, and a plurality of fins 662 as shown in
In some embodiments, the inner seal 626 may include an anti-rotation feature (not shown). The anti-rotation feature may be configured to block circumferential movement of the rub band 632 about the axis 11 relative to seal body 630. The anti-rotation feature may be a pin that extends between the root 661 and the radial outer end 636 of the seal body 630 to block circumferential movement of the rub band 632 relative to the seal body 630.
This present disclosure relates to reducing the complexity of a ceramic matrix composite component or vane 66 by removing structural loads and additional seals from the vane assembly 24. Removing the structural loads and seals from the vane assembly 24, ensures the primary function of the ceramic matrix composite vane 66 is achieved with maximum efficiency. It may also allow easier stiffness control by linking metallic components to get structural optimization of the vane assembly 24.
In some embodiments, the inner sealing between stages in some gas turbine engines may be achieved by mounting abradable material directly to a vane component or mounting an abradable back plate/hanger to a vane component. In a ceramic matrix composite subsystem, such an arrangement may involve multiple metallic to ceramic joints, which are inherently difficult to seal given the large coefficient of thermal expansion mismatch. As such, the present disclosure includes a full metallic structure 68 supporting the static part such as an abradable band 82 of the inner seal 26, a vane 66 in contact with the hot gases in the gas path 28, and minimal joints or interactions between the two materials
In some embodiments, in an inner seal may be used to prevent excessive secondary air system flow leakage between stages. In the illustrative embodiment, the turbine assembly 18 includes a rotating inner seal 26 that engages with a metallic support structure 68, 70 of the turbine vane assembly 24. A portion of the metallic support structure 68 extends through the ceramic matrix composite vane 66, allowing the vane 66 to be supported at the inner and outer interfaces, reducing stresses.
The present disclosure teaches an abradable band 82 applied to the underside 84 of the metallic support structure 70. The abradalble band 82 acts as the interface to the rotating seal fins 62.
In the illustrative embodiment, the inner seal 26 may be installed on a mini-disk 38 or cantilevered from either bladed rotating wheel assemblies 20, 22. If the metal outer support 68 is hollow, then an optional split seal arrangement to allow pressurized air flow to transit from outer to inner cavities.
In some embodiments, the inner support 70 may be an annular ring or segmented part as shown in
If the inner support 70 is segmented, the vane assembly 24 may include strip seals between adjacent supports 70. Careful consideration of the compliance of this system may be desired to ensure adequate sealing across the engine operating envelope.
In the illustrative embodiment of
In the illustrative embodiment of
In the illustrative embodiment of
The axial loading from the pre-swirl nozzle 472 may counteract a proportion of the pneumatic load on the increased radial extent of the outer support 468 and the inner support 470. By pre-swirling, the windage losses may be reduced in the disc cavity
The life of the ceramic matrix composite vane 66, 266, 366, 466 may be unaffected by changes in the metallic support structure design. Therefore, the metallic support structure may be optimized for maximum efficiency. It also allows quick tuning of the fits, joints, thicknesses, and materials during a development. Additional joints/linkages may be applied to the metallic structure, around the outside of the ceramic vane 66, 266, 366, 466.
In some embodiments, the turbine assembly 18, 218, 318, 418, 518, 618 may include a turbine case cooling system. The cooling system may be configured to selectively supply cooling air to the bladed wheel assemblies 20, 22, 222, 322, 422, 520, 620 to control the tip clearance of the blades 40. The cooling system may also be configured to selectively supply cooling air to the vane assembly 24, 224, 324, 424, 524, 624 to manage the temperature and diameter of the outer and inner supports 66, 70, 266, 270, 366, 370, 466, 470. The flow of cooling air supplied may be varied to alter the tip clearance or the inner seal clearance throughout the flight cycle.
In the illustrative embodiment, the seal body 30 includes a hole that extends axially through the seal body 30. The hole may allow tooling access for pushing and/or pre-leaning the seal body 30 before fastening the fasteners 81.
While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
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