Abstract: An air-cooled gas turbine blade providing improved cooling characteristics is disclosed. The turbine blade includes several internal passages for conveying cooling air therethrough during turbine operation to provide the desired cooling effect. Two distinct passages are provided to cool the airfoil leading and trailing edges, respectively. Two serpentine cooling passages are disposed so as to efficiently cool each side of the airfoil. Disposed in the middle of the airfoil is an additional, distinct passage. The platform is cooled by three serpentine cooling passages. Two of these passages are in outlet fluid communication with the inlet to the middle airfoil passage. As cooling air traverses these two passages, heat is transferred, from the base simultaneously cooling it and warming the air. This warmed air is next directed through the middle airfoil passage, providing a slight warming effect to the center portion of the airfoil.

Abstract: A clearance control arrangement for the rotor blade-to-stator shroud clearance in an aircraft engine or other turbo machine. The disclosed arrangements use large area piston-like structures located circumferential to the turbo machine and capable of operation from pressures developed within the machine. One disclosed arrangement incorporates static adjustment capability that can be disposed to provide symmetrical or asymmetrical clearances. The disclosed clearance control can be used as a fast-acting supplement or in lieu of other clearance control arrangements and is arranged to be actuated upon sensing the onset of rotor-to-stator collision pinch point conditions in the turbo machine.

Abstract: A generally wedge-shaped vibration damper for rotor blades of a gas turbine engine has a pair of scrubbing surfaces and is loosely retained in a pocket incorporated in the rotor blade platform. The pocket is partly defined by a plurality of surfaces which orient the damper so that it is slidably displaceable and rotatable only in a predetermined plane. During rotation of the rotor disk, the damper of one rotor blade is displaced in a plane transverse to the rotor axis of rotation by centrifugal forces to a position at which one scrubbing surface of the damper abuts a side surface of the platform of the adjacent rotor blade and the other scrubbing surface abuts an inner surface of the platform of the rotor blade in which the damper is inserted. The scrubbing action of the damper serves to damp vibratory motion in the platforms of both blades.

Abstract: A generally wedge-shaped vibration damper for rotor blades of a gas turbine engine has a pair of scrubbing surfaces and is loosely retained in a pocket incorporated in the rotor blade platform. The pocket is partly defined by a plurality of surfaces which orient the damper so that it is slidably displaceable and rotatable only in a predetermined plane. During rotation of the rotor disk, the damper of one rotor blade is displaced in a plane transverse to the rotor axis of rotation by centrifugal forces to a position at which one scrubbing surface of the damper abuts a side surface of the platform of the adjacent rotor blade and the other scrubbing surface abuts an inner surface of the platform of the rotor blade in which the damper is inserted. The scrubbing action of the damper serves to damp vibratory motion in the platforms of both blades.

Abstract: In a gas turbine engine having an annular casing with a stationary support structure, a high pressure turbine, and an annular high pressure turbine nozzle having at least one stage which includes a plurality of circumferentially aligned nozzle segments and which is disposed in the annular casing between a combustor and the high pressure turbine, a nozzle support arrangement is provided for mounting each nozzle segment to the stationary support structure. The arrangement includes a single mounting pin mounted on and extending from an annular nozzle support flange on the casing support structure and a hole defined in an oval shape in the one end portion of an inner band flange for receiving the mounting pin in an interference fitting relation.

Abstract: A nozzle seal arrangement, for a turbine nozzle of a gas turbine engine, which impedes leakage of high pressure cooling air past the nozzle inner bands into the flow path to the outside thereof. The nozzle seal arrangement includes an annular nozzle support flange attached to and extending along the stationary support structure adjacent to the nozzle, a band flange attached to and extending along the inner band of each nozzle segment and disposed adjacent to the support flange, a continuous seal member having a W-shaped configuration in cross-section which extends circumferentially about the central axis, and an annular recess defined in the forward face of the nozzle support flange which extends circumferentially about the central axis and receives and seats the seal member at the aft side thereof.

Abstract: Nonmetallic airfoil blades are mounted to a rotor disk via a circumferentially spaced array of metal support members. Each support member includes a pair or circumferentially spaced arcuate or airfoil shaped dovetail engagement surfaces. The metal support members are secured to the rotor disk via straight dovetails while the rotor blades are secured to the support members via airfoil shaped dovetails. The support members may include hollow portions for channeling cooling air to the airfoil blades.

Abstract: An impingement-cooled gas turbine blade includes an impingement baffle which, during engine operation, is subject only to shear loading. A tubular baffle body is provided with a pair of mounting flanges which are bonded between a forward portion of the turbine blade and an aft portion of the turbine blade. The bond extends from the blade dovetail to the blade tip.

Abstract: A gas turbine engine has outer and inner counterrotatable annular turbine rotors and pluralities of turbine blades disposed in alternating rows and mounted on and extending between the respective rotors. An interstage seal arrangement for the engine is composed of a sequence of alternating inner and outer seals. Each outer seal is disposed between an interior side of the outer rotor and outer ends of the blades in one plurality thereof being spaced radially inward at their outer ends from the outer rotor and being mounted at their inner ends to the exterior side of the inner rotor. Each inner seal is disposed between the exterior side of the inner rotor and inner ends of the blades in another plurality thereof being spaced radially outward at their inner ends from the inner rotor and being mounted at their outer ends to the interior side of the outer rotor.

Abstract: A rotor disk for a gas turbine engine includes a central load-bearing web portion and a centrifugal pump portion located externally of the load-bearing web portion for pumping cooling air into an array of turbine blades. The pump portion includes an enlarged material section formed homogeneously with the web portion and extends axially forwardly and radially inwardly from the rim of the disk.

Abstract: A gas turbine engine having an outer annular turbine rotor, which is counterrotatable relative to an inner annular turbine rotor, includes attachment structure for attaching turbine blades in circumferential rows to the inner rotor. The attachment structure includes first and second male members of hook-like configurations spaced axially along and circumferentially extending about the rotor, and first and second grooves defined by flanges attached to the rotor and axially spaced along and circumferentially extending about the rotor. The grooves open in a common axial direction for receiving in mated relation respectively and concurrently the hook-like configured first and second male members. The attachment structure also includes several different locking arrangements for locking the male members in mated relation with the grooves to thereby restrain the turbine blade against radial and axial movements relative to the rotor.

Abstract: A clearance control apparatus has a pair of positioning mechanisms for quickly controlling the clearance between rotor blade tips and a shroud segment of a gas turbine engine casing. The positioning mechanisms are supported by axially-spaced casing bosses, coupled to the shroud segment via a shroud holder, and actuatable for moving radially between inner and outer stops. As the positioning mechanisms are moved between the inner and outer stops, the shroud segment is moved therewith toward and away from the rotor axis to respective inner and outer positions relative to the rotor at which corresponding desired minimum and maximum clearances are established between the shroud segment and rotor blade tips. A fluid cylinder on the casing has a piston coupled to the positioning mechanisms by a link.

Abstract: A clearance control apparatus has a positioning mechanism for controlling clearance between rotor blade tips and a shroud segment of a gas turbine engine casing. The positioning mechanism is supported by the casing, coupled to the shroud segment, and actuatable for moving the shroud segment toward and away from the rotor blade tips to reach a position at which a desired clearance is established. The mechanism includes a shaft and a bellcrank actuating assembly. The shaft is mounted through a passage defined by a mounting structure on the casing for radial movement along a longitudinal axis of the shaft toward and away from the rotor axis and is coupled at its inner end to the shroud segment. The bellcrank actuating assembly is coupled to an outer end of the shaft and mounted to the casing adjacent the shaft for pivotal movement about an axis spaced from and extending transverse to the longitudinal axis of the shaft.

Abstract: A clearance control apparatus has a positioning mechanism for controlling clearance between rotor blade tips and a shroud segment of a gas turbine engine casing, and a rotatable lever for actuating the mechanism. The positioning mechanism is supported by a casing boss, coupled to the shroud segment, and actuatable for moving the shroud segment toward and away from the rotor blade tips to reach a position at which a desired clearance is established. The mechanism includes a shaft and a pair of cam elements. The shaft is mounted by the boss for radial movement toward and away from the rotor axis and coupled at its inner end to the shroud segment. An outer cam element is attached to the outer end of the shaft and spaced outwardly from the boss. An inner cam element is attached to an end of the lever mounted to the boss for rotational movement about a longitudinal axis of the shaft.

Abstract: A balance weight for the rotor of a gas turbine engine is adapted to mount within the cavity formed between the innermost surface of the dovetail slots formed in the circumference of the rotor disk and the bottom of the dovetail root of the rotor blades inserted within the dovetail slots. The balance weight has a head portion formed with a bottom surface which mates with the innermost surface of the dovetail slots, and a lip connected to the head portion which engages the aft surface of the rotor disk. The balance weight is supported in an aft direction within the dovetail slots by an aft blade retainer having a shoulder or projection which contacts the balance weight.

Abstract: A mounting assembly for supporting stator vane platforms formed in an extended arc length, such as 90.degree., in a compressor casing, comprising a circumferential flange formed in the compressor casing having spaced clamp arms, a flange carried on each stator vane platform having a surface which is formed with a plurality of radially outwardly extending wedge lock elements, and locking springs having inner and outer sides each formed with wedge lock elements extending radially outwardly therefrom. In order to mount the stator vane platform on the compressor casing, the locking springs are placed in an "unlocked" position on the flange of a stator vane platform wherein the wedge lock elements on the inner side of the locking spring extend between adjacent wedge lock elements on the flange. The vane platform flange and locking spring are then inserted as a unit between the clamp arms of the compressor casing.

Abstract: A joint connection for abutting first and second flanges, particularly the annular flanges of a jet engine and exhaust nozzle, comprises a transverse lip formed on the second flange which overlies the first flange when they are axially engaged. A C-shaped clamp extends over the upper half of the abutting flanges having spaced clamp arms which straddle the flanges so that one clamp arm faces the first flange and the other clamp arm faces the second flange. A locking spring is positioned between the first flange and the adjacent clamp arm, and the facing surfaces of the locking spring and first flange are formed with mating wedge lock elements extending outwardly therefrom. The locking spring is movable to a locked position relative to the clamp arm and first flange wherein the mating wedge lock element of the locking spring and first flange engage one another and force the locking spring against the adjacent clamp arm.

Abstract: A retainer assembly for retaining a bolt in engagement with a first member during assembly or after disassembly of the first member from a second member comprises a retainer formed with a throughbore and an annular slot at one end of the throughbore, a bolt having a shank formed with a smooth section, a threaded section and a groove therebetween, and a triangular-shaped locking ring which is carried within the slot formed in the retainer. The threaded section of the shank of the bolt is first inserted through the locking ring and then into the throughbore of the retainer for mounting within a threaded bore formed in a second member. Upon disassembly of the bolt from the second member, the bolt is moved in the opposite direction along the throughbore of the retainer until the locking ring engages the groove in the shank of the bolt which prevents disengagement of the bolt from the retainer.

Abstract: A boltless blade retainer for preventing forward axial movement of the rotor blades in a turbo machine relative to the rotor disk comprises an annular extension or hook formed on each dovetail post on the web of the rotor disk, an impeller or blade retainer formed with a flange which is carried against the web and dovetail posts and a retaining ring interposed between the hooks of the dovetail posts and the flange of the impeller. The retaining ring secures the impeller in a fixed axial position relative to the dovetail posts and rotor disk, and is positioned to engage the rotor blades carried in the axial slots between adjacent dovetail posts to prevent their movement in a forward axial direction.

Abstract: An improved system provides cooling air to the turbine blades of a gas turbine engine. The improved system includes the combination of an inducer to receive pressurized cooling air from the compressor and then to direct this cooling air in a substantially tangential direction to a radial flow impeller which includes an air seal. Cooling air is directed to the turbine blades which are mounted on the rim of the rotating first turbine disk. In a preferred embodiment of the invention, a second portion of the cooling air from the inducer is conveyed through a deswirler to introduce the cooling air into a circumferential channel surrounding the rotor shaft. The cooling air is then directed to a second inducer means which is mounted on the higher pressure turbine disk. The cooling air is then directed to a second annular impeller mounted on the lower pressure turbine disk to convey this portion of cooling air to the lower pressure turbine rotor blades.