Patent•
Gas turbine engine shroud seals
20 May 1997-
TL;DR: In this paper, a ring seal is provided for sealing a joint between a turbine blade tip shroud and a mounting structure where an annular gap is formed having an "L" shaped cross section, the ring seal having a "C" shaped configuration and one of the legs of the "C", extending within an axial component of the gap.
Abstract: A seal assembly for a turbine blade tip shroud including a one-piece bent metallic sheet inter-segment seal having an axial component and a vertical component adapted to fit in a groove formed in the end walls of each shroud segment, wherein the shroud segment has a plateform and radially extending ribs, and the seal fits tightly in the groove providing an axial an a radial component to the seal. A ring seal is also provided for sealing a joint between the shroud and a mounting structure where an annular gap is formed having an "L" shaped cross section, the ring seal having a "C" shaped configuration and one of the legs of the "C" extending within an axial component of the "L" shaped gap. The leg has a wave pattern with the peaks of the wave in contact with opposite radial walls of the axial component of the gap for creating a gas seal at the joint.
Citations
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Patent•
28 Dec 2001TL;DR: In this article, a U-shaped supplemental seal having reversely folded Ushaped marginal portions is received in a cavity formed in the axially extending sealing surface of the inner rail of the nozzle segment.
Abstract: In a gas turbine having a chordal hinge seal between an inner rail of each nozzle segment and an annular axially facing sealing surface of a nozzle support ring, a supplemental seal is disposed between the support ring and inner bands of the nozzle segments on a lower pressure side of the chordal hinge seals. To minimize or prevent leakage flow across the chordal hinge seals, a generally U-shaped supplemental seal having reversely folded U-shaped marginal portions is received in a cavity formed in the axially extending sealing surface of the inner rail of the nozzle segment. At operating conditions, the marginal portions seal against the base of the cavity and the annular sealing surface of the nozzle support ring to prevent leakage flow past the chordal hinge seal from entering the hot gas path. To install the supplemental seal, the seal is first compressed and maintained in a compressed state by applying one or more wraps about the supplemental seal or an epoxy to secure the seal when compressed in the cavity. At operating temperatures, the retention means releases the seal to engage marginal portions against opposite sealing surfaces of the nozzle segment and support ring.
133 citations
Patent•
27 Jan 2011TL;DR: In this article, an annular support member (14), a turbine shroud (12), and a spring (32) are arranged between the support member and the turbine shroud to push the shroud to a concentric position within the support members.
Abstract: A turbine shroud apparatus is provided for a gas turbine engine having a central axis. The apparatus includes: (a) an annular support member (14); (b) a turbine shroud (12) disposed in the support member (14), the shroud (12) being a continuous ring comprising a low-ductility material and having opposed flowpath and back surfaces, and opposed forward and aft ends; and (c) a spring (32) mounted between the support member (14) and the shroud (12) and arranged to resiliently urge the shroud (12) to a concentric position within the support member (14).
108 citations
Patent•
01 Mar 2010TL;DR: A turbine ring assembly includes a ring support structure and a plurality of ring sectors, each including a single piece of ceramic matrix composite material as discussed by the authors, each of which includes a first portion forming an annular base with an inside face defining the inside face of the turbine ring and an outside face from which there extends two tab-forming portions including ends that are engaged in housings in the ring structure.
Abstract: A turbine ring assembly includes a ring support structure and a plurality of ring sectors, each including a single piece of ceramic matrix composite material. Each ring sector includes a first portion forming an annular base with an inside face defining an inside face of the turbine ring and an outside face from which there extends two tab-forming portions including ends that are engaged in housings in the ring support structure. The ring sectors present a section that is substantially π-shaped and the ends of the tabs are held without radial clearance by the ring support structure. The tabs can have a free length in meridian section that is not less than three times their mean width.
82 citations
Patent•
01 Oct 2009TL;DR: In this paper, a seal housing is provided to substantially cover at least one duct wall of vane array duct of a gas turbine engine, and one example arrangement is employed in a mid-turbine frame.
Abstract: A seal housing is provided to substantially cover at least one duct wall of vane array duct of a gas turbine engine, and one example arrangement is employed in a mid-turbine frame. The arrangement provides improved sealing of the vane array duct through the provision of a plurality of cavities extending along the duct wall. The arrangement may also include insulation tubes to assist in sealing around load transfer spokes passing through the vane array.
79 citations
Patent•
27 Apr 1999TL;DR: A turbine inner shroud and a turbine assembly as discussed by the authors is a turbine stator having a longitudinal axis and having an outer shroud block with opposing and longitudinally outward facing first and second sides having open slots.
Abstract: A turbine inner shroud and a turbine assembly. The turbine assembly includes a turbine stator having a longitudinal axis and having an outer shroud block with opposing and longitudinally outward facing first and second sides having open slots. A ceramic inner shroud has longitudinally inward facing hook portions which can longitudinally and radially surround a portion of the sides of the outer shroud block. In one attachment, the hook portions are engageable with, and are positioned within, the open slots.
71 citations
References
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Patent•
27 Nov 1991TL;DR: A turbine shroud is formed by a ring of butted shroud segments, and each turbine shroud segment has a radially inwardly projecting annular flange which is seated on a radial outwardly facing surface of an annular tip of the outer shroud of the downstream nozzle stage as discussed by the authors.
Abstract: A turbine shroud is formed by a ring of butted shroud segments. Each turbine shroud segment has a radially inwardly projecting annular flange which is seated on a radially outwardly facing surface of an annular tip of the outer shroud of the downstream nozzle stage. This flange is free to slide axially relative to the annular tip during thermal expansion of the nozzle outer shroud in the axial direction. Each turbine shroud segment has a spring seated thereon which urges the radially inwardly projecting flange toward the annular tip of the nozzle outer shroud. Honeycomb material attached to the turbine shroud segment discourages the flow of hot gases through the gap betwen the flange and annular tip of the outer shroud of the downstream nozzle stage attributable to seam chording, thereby reducing the leakage of hot gas into the spaces between the shrouds and the outer casing.
130 citations
Patent•
20 Nov 1992TL;DR: In this paper, the dampers are configured to cooperate with forward and aft seals to also block the axial flow of working fluid through the interblade cavities, and holes are provided in dampers through which cooling air introduced into the interbladed cavities can flow into contact with the platform undersides and cool the platforms.
Abstract: Sheet Metal thermal control dampers are disposed in the cavities between turbine blades to bear against the undersides of opposed blade platforms portions of angularly adjacent blades under centrifugal loading to dampen blade vibrations and to seal the gaps between platforms against the radial flow of working fluid into the interblade cavities. The dampers are configured to cooperate with forward and aft seals to also block the axial flow of working fluid through the interblade cavities. Holes are provided in the dampers through which cooling air introduced into the interblade cavities can flow into contact with the platform undersides and cool the platforms, thereby controlling temperature rise in the blade attachment structure.
96 citations
Patent•
02 May 1983
TL;DR: In this article, an annular turbine blade tip shroud is provided having a construction for minimizing leakage of the cooling fluid and preventing ingestion of hot gases into said cooling flow, a tip shroud support ring is located on the inner surface of said casing with tip shroud members affixed thereto and encasing the blade tips.
Abstract: An annular turbine blade tip shroud is provided having a construction for minimizing leakage of the cooling fluid and preventing ingestion of hot gases into said cooling flow. A tip shroud support ring is located on the inner surface of said casing with tip shroud members affixed thereto and encasing the blade tips. An annular metal can is located over the forward ends of said tip shroud members and has a sealing engagement with the tip shroud support ring. This annular metal can also seals with feather seals located between adjacent ends of cooperating tip shroud members. A positive metal bellows seal is also provided between downstream vanes and the outer casing. A sheet metal seal is located between each tip shroud member and tip shroud support ring to aid in maintaining proper cooling flow through the shroud.
82 citations
Patent•
07 Nov 1986
TL;DR: In this paper, dimensioned slots in feather seals between adjacent edges of platforms of a segmented stator vane for a gas turbine power plant serve to allow the flow of cooling air through the slots notwithstanding the feather seal shifting.
Abstract: Judiciously dimensioned slots in feather seals between adjacent edges of platforms of segmented stator vane for a gas turbine power plant serves to allow the flow of cooling air through the slots notwithstanding the feather seal shifting.
73 citations
Patent•
29 Nov 1991TL;DR: In this article, the outer casing and heat shield are dimensioned and configured so that after thermal expansion the heat shield and outer casing contact to form a gastight chamber therebetween, whereas prior to thermal expansion, the heat shields and outer casings do not.
Abstract: A turbine for an axial flow gas turbine engine has a heat shield arranged in an annular space between the outer casing and an array of butted nozzle segments. The heat shield is made of a material which expands when subjected to the high temperatures generated inside said turbine during operation. A mechanism is provided for blocking rotation about the axial axis and axial displacement in an aft direction of the heat shield, while not blocking radial expansion of the heat shield. The outer casing and heat shield are dimensioned and configured so that after thermal expansion the heat shield and outer casing contact to form a gastight chamber therebetween, whereas prior to thermal expansion the heat shield and outer casing do not form a gastight chamber therebetween. The heat shield is a sheet metal ring.
72 citations