General Electric Company

John J Ciokajlo

Ambrose A Hauser

Samuel H Davison

Michael T O'Brien

Henry B Ritchie

Daniel S Vogt

Harvey M Maclin

Rollin George Giffin

Willard J Dodds

Lawrence Wayne Dunbar

Jeffre Gerry Loewe

The present invention is a unique splitter of a core engine compressor in a double bypass, variable cycle engine. The splitter is extended forward to a second fan section. The extended splitter may divide the rotor blades into outer and inner portions to allow the flow past these portions to act essentially aerodynamically independent of each other in a single or double bypass mode of operation of the variable cycle engine.

Compressor splitter for use with a forward variable area bypass injector

A rotatable turbine frame includes annular outer and inner bands having a plurality of circumferentially spaced apart struts extending therebetween. An annular drive shaft is fixedly joined to the inner band for transmitting output torque therefrom, and the struts are backwardly radially inclined relative to the direction of rotation of the frame so that gas flow between the struts tends to straighten the inclined struts to effect a compressive load component therein.

Rotatable turbine frame

A hybrid gas turbine engine rotor blade includes an airfoil and a dovetail integrally joined thereto. The airfoil includes an inner portion disposed adjacent to the dovetail to provide a structural transition, and an outer portion disposed thereabove for effecting a pressure rise in airflow channeled thereacross. A nosepiece is disposed adjacent to the leading edge of the airfoil inner portion, and a tailpiece is disposed adjacent to the trailing edge of the airfoil inner portion. The nosepiece, tailpiece, and airfoil inner portion are collectively aerodynamically configured for effecting a pressure rise in the airflow channeled thereacross.

Hybrid rotor blade

A gas turbine engine rotor support system includes outer and inner rotors having respective outer and inner blades interdigitated in respective blade row stages. A stationary rear frame includes a rear support shaft. A rotatable aft frame is disposed forwardly of the rear frame includes an aft support shaft. And, a rotatable forward frame is disposed forwardly of the aft frame and includes a forward support shaft. The forward and aft frames support the outer and inner rotors, and a first bearing is disposed between the aft shaft and the rear shaft for supporting the aft shaft; a second bearing is disposed between the forward shaft and the aft shaft for supporting the forward shaft; and a third bearing is disposed between a core shaft of a core turbine and the forward shaft for supporting the core shaft thereon.

Gas turbine engine rotor support system

A method and assembly are effective for air-starting an aircraft gas turbine engine having a fan powered by a low pressure turbine through a first shaft, and a compressor powered by a high pressure turbine through a second shaft disposed coaxially therewith. A gear train is selectively operatively joined between the first and second shafts by selectively engaging a first clutch for transmitting torque through the first clutch only in one direction from the first shaft to the second shaft when the fan is windmilling for driving the second shaft to allow an air-start of the gas turbine engine during flight. In a preferred embodiment, a second clutch is operatively joined to the gear train and is selectively engageable at speeds of the second shaft below a predetermined release speed, and disengageable at the release speed and above for disconnecting the air-start assembly once the engine has been started.

Air-start assembly and method

A counterrotating turbine support assembly includes outer and inner rotors having respective outer and inner blades disposed in an outer casing. A mid-frame is disposed forwardly of the rotors and fixedly joined to the outer casing. A rear frame is disposed axially aft of the rotors and is fixedly joined to the outer casing. A forward support shaft is joined at one end to a forward end of the outer rotor and is rotatably supported at an inner end to the mid-frame by a forward bearing. An aft support shaft is joined at one end to an aft end of the outer rotor and is rotatably supported at an inner end to the rear frame by an aft bearing. An intermediate support shaft is fixedly joined at one end to the inner rotor and is rotatably supported at an inner end to the mid-frame by an intermediate bearing.

Counterrotating turbine support assembly

A lubrication system for a gas turbine engine includes first and second coaxially rotor shafts having at least one differential bearing disposed in outer and inner seats thereof. An annular first scoop extends axially from a first portion of the first shaft, and an annular second scoop extends axially from the inner seat of the second shaft. A plurality of first holes extend axially through the first shaft and radially below the first scoop, and a plurality of second holes extend axially through the inner seat of the second shaft and below the second scoop. An annular first shell extends axially between the second scoop and the first shaft from above the first holes. And, oil is injected under the first scoop for flow by centrifugal force from rotation of the first shaft through the first holes and along the first shell into the second scoop for flow through the second holes to lubricate the bearing.

Gas turbine engine lubrication system

A combustion assembly includes a combustor having inner and outer pilot liners, each being in the form of a lobed mixer having outer and inner cold and hot chutes. A plurality of carburetors are joined to a dome disposed at upstream ends of the liners for providing a pilot fuel/air mixture for generating pilot combustion gases in the hot chutes. A plurality of fuel spraybars are disposed downstream from the carburetors and are aligned radially with the cold chutes for selectively injecting main fuel into main airflow for generating a main fuel/air mixture ignitable by the pilot combustion gases. In a preferred and exemplary embodiment of the invention, lean combustion gases are obtained for reducing NO.sub.x emissions in a relatively short residence time.

Staged, mixed combustor assembly having low emissions

A clearance control assembly in a gas turbine engine includes several stages of cylindrical turbine shroud rings and a one-piece continuous cylindrical housing surrounding the shroud rings in radially outward spaced relation. Each shroud ring is composed of at least a pair of semi-cylindrical segments mounted to the housing. The shroud ring segments are radially positioned by thermal expansion and contraction of the housing in response to temperature-controlled air flow between the housing and shroud segments. Coupling elements joins together opposite edge portions of adjacent shroud ring segments to permit axial movement of the shroud segments toward and away from one another. Lands which protrude outwardly from the housing interior and shroud ring segment exteriors are located between the housing and shroud segments for defining several spiral channels for air flow about the interior of the housing and exterior of the shroud segments. Conduits are provided for supplying a flow of temperature-controlled air to the spiral channels between the housing and shroud segments.

Clearance control assembly having a thermally-controlled one-piece

A gas turbine engine incorporates a bearing support assembly which mounts an inner annular bearing arrangement in radially spaced relation inwardly from a stationary outer casing. The bearing arrangement, in turn, mounts a turbine rotor within the outer casing for rotation about a central axis relative to the outer casing. A row of stationary stator vanes are fixedly attached to an extend radially inwardly from the outer casing toward the central axis. The bearing support assembly includes an inner ring structure extending about and mounting the inner bearing arrangement, elongated tie rods each having opposite outer and inner end portions and being disposed in circumferential spaced relation to one another and extending through the stationary vanes in radial relation to the central axis and between the outer casing and inner ring structure, and fastening elements fixedly clamping the outer casing and inner ring structure respectively to the outer and inner end portion of the tie rods such that the tie rods, outer casing and inner ring structure act together as a unit to uniformly distribute bearing-induced radial loads and to withstand bearing-induced radial loads in both tension and compression. An annular shell structure is disposed between and fixedly interconnects the inner ring structure and stationary vanes such that the annular structure, inner ring structure and stationary vanes act together as a unit to withstand axial loads induced by differences in air pressure existing axially through the outer casing.

Lightweight engine turbine bearing support assembly for withstanding

A turbine assembly includes a unitary rotor spool having first and second rotor discs. A set of first blades having axial entry dovetails are joined to the first disc, and a set of second blades having axial entry dovetails are joined to the second disc. A unitary annular spacer is disposed axially between the first and second dovetails for preventing the first and second blades from sliding axially toward the spacer. The spacer has an inner diameter greater than an outer diameter of the first rotor disc for allowing the spacer to be assembled over the first rotor disc during assembly.

Turbine assembly

A combustor includes spaced outer and inner liners defining therebetween a combustion zone, and having a plurality of circumferentially spaced tubular domes disposed between forward ends thereof. Each of the domes includes an annular inlet for receiving pilot airflow, a swirler having a tubular ferrule and primary swirl vanes for receiving the pilot airflow, and an outlet disposed in flow communication with the combustion zone. A pilot fuel injector is disposed in each of the domes for injecting pilot fuel into the pilot airflow for generating a pilot fuel/air mixture dischargeable from the dome outlet. A plurality of main fuel spraybars inject main fuel into compressed airflow channeled between the domes and the outer and inner liners for generating a main fuel/air mixture dischargeable concentrically around the pilot fuel/air mixture. And, the pilot fuel/air mixture is ignited for generating pilot combustion gases in the combustion zone which are effective for igniting the main fuel/air mixture for generating main combustion gases in the combustion zone.

Compact flameholder type combustor which is staged to reduce emissions

An apparatus for controlling clearance between rotor blade tips and shroud segments of a turbine engine casing includes an annular channel extending about the blade tips and having an annular opening located outwardly of and adjacent the blade tips, and separate shroud segments composing the shroud and disposed across the channel opening in circumferential spaced relation. Inlet and outlet tubular members mounted to the casing have inner portions projecting radially inwardly into the annular channel. An annular hollow ring disposed in the annular channel mounts the shroud segments across the channel opening and are mounted to the tubular member inner portions for undergoing movement radially outwardly and inwardly relative to the inner portions in response to thermal expansion and contract of the annular ring. Tubular inlet members introduce a cooling gas into the annular channel from the exterior and tubular outlet members exhausts the cooling gas from the annular channel to the exterior. Hollow manifolds disposed within the annular channel in the annular ring are connected with the inner portions of the tubular inlet members for receiving cooling air. Each manifold has jet-like apertures permitting impingement of cooling air upon the annular ring. After such impingement, the cooling air can flow from the annular ring through the tubular outlet members to the exterior.

Blade tip clearance control apparatus using shroud segment annular

A mechanical clearance control apparatus is operable for controlling the clearance between the rotor blade tips and the casing shroud of a gas turbine engine. The apparatus includes a shroud segment which defines a circumferential portion of the casing shroud and is disposed in an opening defined by a mounting section of the stationary casing, a channel defined between radially spaced portions of the shroud segment and the stationary casing mounting section, and a wave spring disposed in the channel and preloaded against the shroud segment and mounting section for biasing the shroud segment to move radially inward toward the rotor. Flanges on opposite sides of the shroud segment and on the stationary casing mounting section at opposite sides of the opening cooperate to define inner and outer limits of radial movement of the shroud segment as the shroud segment is moved toward and away from the rotor. A mechanism is rotatably mounted to the stationary casing mounting section, threadably coupled to the shroud segment and pivotaly linked to a unison ring for moving the shroud segment toward and away from the rotor to set the clearance between the shroud segment and the rotor blade tips upon rotational movement of the unison ring.

Blade tip clearance control apparatus for a gas turbine engine

A support bearing assembly for supporting a jet aircraft engine high speed rotor shaft where an operating temperature of up to 1500 degrees F. is involved and the bearing unit is exposed to such temperature condition, includes a rolling elements-inner and outer race bearing unit capable of operating at such temperature level without adverse effect and, e.g., these components being comprised of ceramic matrix composites. Since such a bearing unit will have different thermal growth than its metallic support housing, the bearing unit is supported in pairs of opposed cylindrical cages, there being an inner cage pair for holding the inner race and an outer cage pair for holding the outer race. The cages have flange means at one end and circularly, spaced support arms extending from the flanges a distance to cage opposite end locations where the support arms are formed as finger structures which interfit with the race members, the spacing between the support arms defining slots in the cage bodies. Fixing pins are carried in the finger structures and interfit with passages or grooves formed in the races. The support arms are flexible in the radial direction but are stiff in tangential or circumferential directions so the radial flexibility permits radial thermal differential growths in the supporting components while keeping the bearing unit supported and radially constrained. The cage units will have high thermal expansion characteristics whereas others of metallic components in the assembly will be intermediate value with that of the ceramic bearing unit being the lowest.

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Cincinnati, OH, United States of America

John J Ciokajlo