Abstract: A removable inspection hole plug for sealing a plurality of inspection holes formed in a double-walled enclosure is disclosed in which individual sealing units are disposed in each of the inspection holes, with the individual sealing units linked together by a link rod pivotally attached to each of the sealing units. A seal is provided on each of the sealing units which slideably engages a wall defining the inspection hole and the link rod may be attached to the sealing units by a ball and socket swivel joint. One of the sealing units is attached to a housing which is, in turn, removably attached to the enclosure such that the sealing unit may undergo limited axial movement relative to the housing. This accommodates differential thermal expansion between the walls of the enclosures and also facilitates removal of the inspection hole plug by merely unfastening the housing from the enclosure and removing the housing along with the sealing units.

Abstract: A seal support assembly for a gas turbine engine includes a stator seal support having an annular seal backing extending axially away therefrom and having an integral retention flange at one end thereof. The retention flange includes a retention groove. An annular seal block is supported radially inwardly of the seal backing for cooperating with rotor seal teeth to define a fluid seal. A control ring is disposed radially outwardly of the seal backing and is supported thereby, with the control ring having a plurality of circumferentially spaced apart retention tabs cooperating with the retention flange for axially retaining the control ring on the seal backing. An annular heat shield is fixedly joined at one end to the seal support, and includes a plurality of circumferentially spaced apart retention tabs cooperating with the retention flange for axially retaining the heat shield to the seal backing while permitting unrestrained differential radial movement therebetween.

Abstract: In a gas turbine engine tip clearance between rotor blades and an encircling shroud liner is controlled by moving the shroud liner radially to match the thermal and centrifugal growth of the rotor assembly. The shroud liner segments are suspended between two axially displaced control rings located in a passageway carrying air ducted from the compressor. One control ring responds very quickly to changes in gas temperature corresponding to centrifugal growth and blade thermal growth. The other ring responds very much more slowly and corresponds to the thermal growth of the disc. The shroud liner segments are suspended from the control rings to adopt a position that constitutes the average between the growth positions of the two control rings.

Abstract: A gas turbine engine having a main casing, turbine blades and a segmented cylindrical liner surrounding the tips of the blades is provided with apparatus for compensating for different radial expansions between the blades and the liner. The apparatus comprises a shroud structure, such as a platform of an axially adjacent nozzle guide vane, and a slipper element extending radially from the shroud structure to the liner and coupling one to the other. The slipper element expands circumferentially more slowly than does the shroud structure. Thermal circumferential growth of the shroud structure causes a radial displacement of the liner segments relative to the shroud structure.

Abstract: A thermal radiation shield is joined to an annular casing through which combustion gases are axially flowable. The shield is spaced at least in part radially inwardly from the casing inner surface and includes axially spaced apart forward and aft edges and radially outer and inner surfaces extending axially therebetween. The shield includes a trough disposed in the outer surface which faces the casing inner surface, and the trough extends along the shield at least in part both axially and circumferentially. A flow conduit extends through the casing and in flow communication with the trough for channeling cooling air thereto. The shield protects the casing from thermal radiation, and the trough is effective for channeling the cooling air both circumferentially and axially for reducing thermal gradients.

Abstract: A guide vane ring having guide vanes is provided on two rings which are arranged coaxially and radially at a distance from one another. These two rings are held on assigned housing sections which are subjected to thermally different expansions. One ring is rigidly connected with the guide vanes, and the other ring is connected with the free ends of the guide vanes by the compressive force of a tensioning element. In addition, the other ring is divided into several piston-ring-type elements which axially follow one another and which are each slotted approximately axially and form a cylindrical sliding surface for the whole free ends of the vanes. The tensioning element is arranged on the one group of assigned housing sections while forming a radial compressive force distributed uniformly on the elements.

Abstract: A locator pin retention device comprises a pin with threaded and smooth portions cooperating with a bushing having spaced apart threaded and smooth portions to allow alignment of inner and outer gas turbine engine members exposed to different thermal environments, allowing thermal growth of the inner member in a radially outward direction toward the outer member and reacting axial and circumferential loads to prevent transverse movement to the outer structural member. The device reduces machining of the structural members because machined retention means are inexpensive and replaceable parts.

Abstract: A mounting system for a stator vane assembly is disclosed for mounting a vane and its cooling system to minimize the thermal and mechanical stresses imparted to the vane structure. Platforms are attached to opposite ends of the vane, which has a hollow interior and a cooling gas distributor located within the interior of the vane. One end of the cooling gas distributor is also fixedly attached to one of the vane platforms, while the opposite end of the cooling gas distributor is attached to a casing, not to the opposite vane platform. Spaces are defined between the cooling gas distributor and the vane platform, as well as the casing and the vane platform. A gas inlet sleeve may be attached to the cooling distributor and serve as its attachment to the external casing.

Abstract: A multi-stage centrifugal pump wherein a casing surrounds an impeller and a fluid flow guiding insert in each pump stage. The casing is made of a ferritic material, and the inserts are made of an austenitic material. The casing defines with each insert a first clearance wherein a cylindrical surface of the casing is surrounded by a cylindrical surface of the respective insert so that the width of the clearance increases in response to heating of the inserts and of the casing at the respective first clearances. The casing further defines with each insert a second clearance which is disposed radially outwardly of the respective first clearance and wherein a frustoconical surface of the casing surrounds a complementary frustoconical surface of the respective insert so that the width of each second clearance decreases in response to heating of the casing and of the inserts at the respective second clearances.

Abstract: An axial-flow compressor in which rotor blade clearance, in an area where the stator case surrounding a rotor blade stage is unsupported, is controlled by the cross-sectional area of a ring surrounding the stator case and by a gap between the inner surface of the ring and the outer surface of the stator case established at the time of compressor build.

Abstract: Clearance control is provided by circumferentially segmented cooling manifolds having spray bars located radially outside selected components of the stator casing. Cooling air is directed onto stator components and returns immediately through circuitous paths to improve uniformity of cooling. The spray bars extend through limited circumferential angles to limit distortion due to uneven heating.

Abstract: A turbine support for reacting structural loads from a rotor bearing cage to a case of a gas turbine engine. The turbine support includes a homogeneous main casting and a rotor bearing cage. The main casting has concentrically arranged inner, intermediate and outer walls. The bearing cage is radially inboard and a rigid appendage of the inner wall. The inner and intermediate walls define therebetween a longitudinal segment of the annular hot gas flow path of the engine. The outer wall is bolted to the engine case. The inner wall is connected to the intermediate wall by a plurality of generally radially oriented, angularly separated inner load bearing struts of the main casting. The outer wall is connected to the intermediate wall by a plurality of radially oriented, angularly separated outer load bearing struts of the main casting.

Abstract: The normally multi-part gas turbine engine labyrinth seal outer portion which carries an abradable lining, is formed from a single piece and has a groove machined in its periphery for the receipt of the feet of respective stator vanes. Pins are fitted in pairs through the walls of the groove to provide lateral location for the feet. The pins and a groove liner are made from an anti-frettage material.

Abstract: A live steam passage of double-shell design for steam turbines is disclosed. According to the present invention, the steam passage is welded as a welded-in insert (1) onto the outer housing (9) of the turbine. The piston ring supoprt sleeve (2) with the piston rings (4) slides as a separate part in a sleeve (5), which the sleeve (2) is screwed onto the welded-in insert (1) with locking screws (3). A threaded ring (6) provided with a high collar holds the sleeve (5) in place in the inner housing (7) of the turbine. The live steam passage according to the present invention can be used in steam turbines, including throttle-controlled steam turbines with inner housings.

Abstract: In a turbine inclusive of: a turbine shaft having a longitudinal axis, a steam pipe, a shell circumadjacent the pipe, the pipe and shell being shiftable in vertical and transverse and axial directions relative to the longitudinal axis of the shaft, and a seal assembly disposed between the pipe and shell and comprising a stack of interdigitated relatively large and small piston rings, the improvement comprising: each large ring loosely fitting inside the shell during nonoperative conditions and firmly and sealingly engaging the shell during operative conditions; and having a coefficient of thermal expansion greater than that of the shell for expanding at a rate faster than the expansion rate of the shell under a condition of increased temperature, each small ring loosely fitting around the pipe during nonoperative conditions and firmly and sealingly engaging the pipe during operative conditions; and having a coefficient of thermal expansion less than that of the pipe for expanding at a rate slower than the exp

Abstract: A unitary exhaust gas housing for a turbo-engine comprises an outer ring, two intermediate rings defining the flow path for the hot gases, and an inner ring forming a hub with a hollow annular chamber. A temperature control device is provided including a bleed tube having one end fixed and communicating with the gas flow path for drawing off hot gases therefrom, the other end of the tube passing into the hollow chamber of the hub where it regulates the flow of gases by variation of the clearance j between the end of the tube and the opposing wall of the hub in response to relative radial movements of the tube and the hub according to the thermal states of the assembly.

Abstract: An improved steam turbine system is provided having a hardfacing disposed on a portion of its steam inlet chamber wear surfaces. The invention also includes a novel stacked ring design having a hardfaced inlet sleeve and stationary, nitride sealing rings for minimizing wear. Also included are novel heat treatments and metallurgical processes for stress relieving these hardfaced components. The techniques and designs employed, decrease steam leakage and assure longer service life for steam powered turbines.

Abstract: An axial flow steam turbine has a nozzle ring circumferentially about the rotor thereof and inner and outer sections forming the ring with confronting channels therein, and a plurality of nozzle chambers communicating with the spacing between the ring sections. A plurality of nozzle blocks having radially outwardly and inwardly extending flanges are positioned in the inlet nozzle such that the same are retained therein under compressive forces exerted by the nozzle ring sections. A method for forming the same is also provided.

Abstract: A coolable stator assembly is positioned outwardly of an array of rotor blades in a high by pass turbofan gas turbine engine as disclosed. The stator assembly includes case tied air seals positioned by rails and a shield which extends circumferentially about the rails and the rail connector section extending between the rails. Various constructions details for improving the control of clearances and circumferential temperature gradients in the rails are developed. In one particular embodiment, cooling air tubes are employed with the shield.

Abstract: A nozzle chamber assembly comprising an upper nozzle chamber resting on a lower nozzle chamber wherein the nozzle chambers are neither bolted nor pinned at their horizontal juncture but are held together by gravitational and pressure forces. A removable bolt which passes through the upper portion of the inner cylinder during assembly of the turbine and threads into the upper portion of the nozzle chamber to fasten the upper nozzle chamber in the upper portion of the inner cylinder during assembly and is removable once the inner cylinder is assembled. The inlet nozzles for the turbine and nozzle chambers are slidably received and sealed in a common bore which extends through the inner cylinder.

Abstract: Apparatus and method for reducing thermal stress in the casings of a steam turbine. A novel inlet sleeve carries high pressure steam from the bell connector of an inlet pipe through the turbine inner casing. The inlet sleeve is connected at a first end to the bell connector and secured at a mid portion to the inner casing so that the second end of the inlet sleeve may terminate adjacent the inner casing wall without contacting the inner casing. This connection means forms a cylindrical chamber having a closed end at the mid portion of the inlet sleeve and an open end adjacent the inner wall of the turbine inner casing. The cylindrical chamber provides a thermal shield which isolates portions of the turbine inner casing adjacent the inlet sleeve from the rapid steam flow between the inlet pipe and the turbine blading.

Abstract: A linkage (36) is provided for manipulating an internal component (32) of a turbofan gas turbine engine (10) in response to an externally mounted actuator (50). The linkage includes a radial torque shaft (38) supported between two spherical bearings (40, 42). The shaft (38) is slidable within the radially outer bearing (42) for accommodating relative radial movement in addition to relative axial and circumferential movement between the inner compressor case (26) and the outer fan duct (28).

Abstract: A rotor blade jacket for an axial gas turbine has a closed ceramic ring surrounding the blade tips of the turbine rotor and surrounded by a protective metal ring holding heat expansion compensating bristles which are secured at their radially outer ends to the protective metal ring and at their radially inner ends to the ceramic ring, whereby the ceramic ring is supported and centered in the turbine housing.

Abstract: In a turbine machine, a two component shroud seal which maximizes insulation and sealing around the rotating turbine blades and made by independently fabricating each of the two components then joining them together is disclosed. The two components may be joined together at room temperature. The resulting shroud seal provides greater engine efficiency and thrust.

Abstract: A stator assembly 18 for a gas turbine engine is disclosed. Various construction details relating to the mounting of a stator vane 42 in the engine are developed. In one embodiment, the vane is: bolted at a downstream flange 112 of the vane to an inner support 54; radially splined to a support such as the outer support 56 at an upstream flange 125 which is spaced axially from the downstream flange; and, is adapted to slidably engage the outer support to provide sealing contact between the vane and the remainder of the engine.

Abstract: An expansion joint for sealing the periphery of a component passing through a bore in a member comprises a component sealing element and a bore sealing element, each having a respectively alignable hole therethrough for defining an opening for receiving the component through the expansion joint. The radial outer surface of the bore sealing element sealingly engages the bore and the radial inner surface of the component sealing member that defines the hole therethrough is radially outwardly relieved over a first portion so that a second portion of the inner surface sealingly contacts the periphery of the component along a line which is everywhere tangent to the component, thereby accommodating skew between the central axis of the component and the central axis of the bore. Lateral surfaces of the component and bore sealing elements are mutually sealingly engaged during assembly.

Abstract: A stationary blade assembly with a segmented inner shroud to permit radial expansion and contraction of the blades and circumferential expansion and contraction of the shroud segments and a seal plate which fits into a circumferential groove in the shroud segments and is held therein by pinned keys which slide in kerfs in the outer edge of the seal plate and a labyrinth seal strip disposed in a circumferential groove in the inner edge of the seal plate to provide a small clearance seal not affected by thermal gradients.

Abstract: A stator structure 34 for supporting an outer air seal 46 is disclosed. Various construction details which adapt the stator structure to evenly move inward and outward in response to the impingement of cooling air are developed. In one embodiment an upstream support ring and a downstream support ring for the outer air seal are attached together.

Abstract: A housing for a rotor of a turbomachine comprising, radially spaced inner and outer casings. The inner casing comprises a plurality of segments 20(a) to 20(e) each of which comprises one or more stator vanes 23. A first of the casings 19 has two or more axially spaced locating members 21,22 which co-operate with locating means 25,29 on the second of the casings 18 to locate the first casing 19 relative to the second casing 18. A first of the locating means 25 comprising a first surface 27 inclined to a direction extending axially along the second casing 18 and a second surface 28 that constitutes a sealing face. A first of the locating members 21 having a third surface 32 that confronts the first surface 27. In use, axial gas loads on the stator vanes 23 cause the first and third surfaces 27,32 to engage each other and slide along the incline to bring a fourth surface 33 on the member 21 into sealing engagement with the said second surface 28.

Abstract: A pump comprising an outer casing, an inner liner and a rotatable impeller, the liner being mounted to the casing in a manner such that the liner is substantially secured against rotational movement within the casing but can expand, contract or deflect radially from the centerline of rotation of the impeller.

Abstract: A sealing device is disclosed for maintaining a small positive clearance between packing segments and the turbine blade tips of a turbojet engine. The packing segments are connected to an inner ring which is, in turn, connected to an outer ring, all disposed within the turbojet casing. The coefficient of thermal expansion of the inner ring is greater than that of the outer ring such that, as air is directed onto the structure from the engine compressor, the differential expansion or contraction of the rings serves to move the packing segment in a radial direction to maintain the clearance between them and the turbine blade tips.

Abstract: A one-piece, investment cast stator structure is provided including inner and outer shrouds 14 and 12 with a hollow airfoil-shaped vane therebetween and with areas 34, 36, 42 and 44 in the vicinity of the intersections of the shrouds with the airfoil vane walls being of reduced thickness relative to the remainder of the shrouds to provide improved properties of the material in these areas to better respond to thermal stresses imposed on the structure.

Abstract: The present invention pertains to a means of connecting a primary pump (intended for sodium or the like) and the delivery pipe within a breeder reactor of the swimming-pool type, permitting limited movement of the pump and the pipe in relation to one another to occur, while also maintaining adequate sealing between low pressure areas and high pressure areas within said pump. The connecting component consists of a cylindrical sleeve (11) which, in a resting position, is situated along the same axis (1) as the delivery pipe for the pump. A cylindrical guide (3) which is fastened to the pump is fitted into the aforementioned pipe, and a sealing joint (13) is situated between the sleeve (11) and the guide (3). There is also a horizontal annular collar (12) which is fastened to the aforementioned sleeve (11), resting upon an annular rim (5) situated upon the upper flange (7) of the pipe (4).

Abstract: A coolable stator assembly 18 positioned outwardly of an array of rotor blades 32 in a gas turbine engine is disclosed. The stator assembly includes an outer case 48 and an outer air seal 76 positioned outwardly of the array of rotor blades by the outer casing leaving a variable clearance gap G therebetween. The outer case has an upstream flange 52 and a downstream flange 54 for joining the outer case to adjacent cases 46, 50. A coolable rail assembly 22 for varying the diameter of the outer air seal and the clearance gap G is attached to the outer air seal. Various construction details for improving the sealing effectiveness of the stator assembly are developed. The coolable rail assembly is supported inwardly of a plurality of spray bars 26 from the upstream flange and the downstream flange. In one embodiment, a first section 102 and a second section 104 of the outer casing support the rail assembly from the flanges.

Abstract: A nozzle of a gas turbine engine includes an array of radially extending guide vanes fixedly supported at their tip portions to an outer shroud, while the root portion of each vane is connected to a segment of a radially inner, segmented shroud. Each segment is, in turn, connected via a slip fit inter-connection to a radially inner ring support structure of generally L-shaped configuration. A spring extends between the segment and the base of the L-shaped ring support for forming a flexible coupling between the inner ring and the segment, while the remaining portion of the ring support structure defines a pressure dam to reduce leakage through the flexible coupling connection. The segmented nozzle construction effectively reduces stress levels resulting from differential thermal excursions of the components of the nozzle under transient and steady state operation of the engine, while also minimizing leakage through the flexible coupling.

Abstract: An annular sleeve surrounds a turbine rotor and is fixed to a stationary part, the sleeve being elastically deformable in a radial direction. A wear ring is carried by the sleeve, the wear ring being composed of segments arranged end-to-end circumferentially. The adjacent ends of the segments are spaced apart at all operating conditions of the turbine. The thermal expansions of the turbine rotor and of the sleeve and ring are so related that under operating conditions of the turbine, when the engine of which it forms a part is running, the sleeve thermally expands radially. The rate of thermal expansion of the stationary part is directly related to the rate of thermal expansion of the turbine rotor. Air leaving the compressor is directed against the sleeve and the stationary part carrying the sleeve. The wear ring and portion carrying the sleeve may be insulated. The sleeve may be mounted on a combustion chamber surrounding the turbine.

Abstract: An annular sleeve surrounds a turbine rotor and is fixed with respect to the turbine casing, the sleeve being elastically deformable in a radial direction. A wear ring is carried by the sleeve, the wear ring being composed of segments arranged end-to-end circumferentially. The adjacent ends of the segments are spaced apart when the turbine is cold or idling. The thermal expansions of the turbine rotor and of the sleeve and ring are so related that in one operating temperature range of the turbine the spaces between the adjacent ends of the ring segments close and the segment ends engage each other, and in a higher operating temperature range of the turbine the sleeve expands. Air leaving the compressor is directed against the sleeve and the stationary part carrying the sleeve. The wear ring and portion carrying the sleeve may be insulated. The sleeve may be mounted on a combustion chamber surrounding the turbine.

Abstract: A sealing device including a sealing ring extending around the periphery of a gas turbine stator section and located between the stator section and the free ends of the stator vanes. The sealing ring is formed of individual segments movable radially relative to each other. Each two adjacent sealing ring segments have opposed faces, one face presenting projections and the other having correspondingly shaped recesses for accommodating the projections with clearance. Each opposed face has a groove at least as deep as the projection or recess in that face, and a flat plate is located in the opposed grooves. Springs or gas pressure press the sealing ring segments radially outwardly against the free ends of the vanes. The radius of curvature of the ring segments outer surfaces is smaller than that of the vane ends so that the segments and vane ends contact each other over only a portion of their surfaces.

Abstract: A turbocharger construction of the divided turbine housing type. To prevent failure of the divider wall due to thermally induced stresses, the divider wall is separate from the housing and means are provided to enable at least the major portion of the divider wall to move radially with respect to the housing.

Abstract: Seal for two concentric tubular elements of a gas turbine, consisting of rings associated with each element and having facing grooves, and of a connector extending between the grooves and consisting of two annuli which are in concentric spaced relationship and are joined by a web.

Abstract: A system is provided inside a turbomachine for controlling operational clearance between a turbine rotor and a surrounding turbine shroud. The system comprises a plurality of control rings, integrated into the turbine casing, that are thermally expanded and contracted to control radial positioning of the turbine shroud. Compressor air is directed through internal passages in the rings to cause the expansion and contraction. The system utilizes the pressure and temperature of compressor air, in combination with size, location, and structure of the control rings to match thermal growth of the control rings and turbine shroud to thermal growth of the turbine rotors, thereby controlling clearance.

Abstract: A multi-stage axial flow steam turbine having an inner and an outer casing. The inner casing being a pressure vessel having a first end which is enclosed by a nozzle ring disposed around a rotor in closely spaced, sealed relation therewith and having a second end which is open to the interior of the outer casing. Sealing between the inner casing and nozzle ring is provided by a structural hook seal which includes mateable flange portions which are integral with the inner casing and nozzle ring. A control stage and a first plurality of reaction stages are disposed within the inner casing. A second plurality of reaction stages are also disposed between the outer casing and the rotor so that steam leaving the inner casing's second end flows over the inner casing's outer surface and over the nozzle ring's outer surface to cool those outer surfaces before the steam enters the second plurality of reaction stages.

Abstract: A gas turbine engine blade tip seal consists of a sealing ring which is controlled by means of two annular control members. The members are arranged such that one control member has a relatively rapid thermal response rate and the other control member has a relatively slow thermal response rate, the sealing ring being controlled such that a preferred tip clearance is maintained under varying engine operating conditions.

Abstract: A turbine cylinder is in contact at its outer surface with split rings which are held in place in annular slots in a cylindrically extending ring holder. The rings, while remaining in contact with the outer surface of the cylinder, are allowed to expand and contract within their respective slots. Notches are constructed at the inner circumference of the rings to form a labyrinth type cooling passage in conjunction with the outer surface of the turbine cylinder.

Abstract: The present invention provides improved concepts for making judicious use of vane cooling air without introducing mechanical stresses or differential growth induced deformation into the structure. Maintenance of an adequate pressure differential across a tubular insert without inhibiting thermal growth is sought and a specific object is to closely control the leakage of cooling air between a slidable end of the insert and the interior of the vane.In one effective embodiment incorporating concepts of the present invention, a tubular insert 26 is affixed to the vane at one end 32 thereof and is free to slide along the interior surface 28 of the vane at the other end 34 thereof. Leakage of cooling air between the insert and the vane is controlled by closely toleranced correspondence of a closure plate 36 at the slidable end of the insert with a cooling air supply tube 38 which penetrates the closure tube.

Abstract: Locking structure for maintaining a set position in assembling an annular seal ring housing to a stationary inner shroud of an annular array of vane segments of a combustion turbine engine. This permits an adjustable assembly for obtaining concentricity between the seal and the adjacent rotor structure. Thus, the seal ring is mounted to the vane segments through an adjustable mounting arrangement that, upon assembly of the two, permits the seal ring to be aligned concentrically about the rotor. Once concentricity is obtained, the mounting components must be locked in such position to maintain such concentricity. The present invention provides a bracket attached to the adjustable mounting structure to lock it in the set position.

Abstract: An active clearance control (ACC) for a turbofan engine is disclosed herein where the cross section of the external spray bars are fabricated in square or substantially square configurations.

Abstract: A turbine shroud assembly includes an expansion control ring to support segmented rotor shrouds. The expansion control ring is restrained by adjacent manifold rings, yet free to thermally expand radially outwardly without loss of axial alignment with the associated turbine wheel. The ported manifold rings are positioned on either side of an outwardly extending leg of the expansion control ring to direct cooling fluid delivered thereto toward the expansion control ring. A spacer ring surrounds the expansion control ring and restrains the expansion control ring relative to the manifold rings. The spacer ring maintains axial alignment of the expansion control ring with the turbine wheel. Cooling fluid is exhausted into the main hot gas stream, both upstream and downstream of the turbine wheel thus substantially preventing hot gases from affecting the expansion control ring.

Abstract: A support structure for an outer air seal of a gas turbine engine is disclosed. Various construction details which improve the sealing effectiveness of the outer air seal are developed. The outer air seal is held in close proximity to the rotor blades by the circumferentially adjacent support segments.

Abstract: A single turbomachine support structure provides both close tolerance radial positioning of a turbine shroud and close tolerance axial positioning of a vane. Radial movement of the vane without attendant radial movement of the shroud is accommodated by the use of surfaces designed to minimize constraint between the vane and the support structure. The linkage is further provided with cooling means to isolate thermal variations proximate the vane end thereof from the support structure end thereof.