A turbine includes a plurality of inner shell sections mounting first and second stage nozzle and shroud portions. The inner shell sections are pinned to an outer containment shell formed of sections to preclude circumferential movement of the inner shell relative to the outer shell and enable thermal expansion and contraction of the inner shell relative to the outer shell. Positive bucket tip clearance control is afforded by passing a thermal medium about the inner shell in heat transfer relation with the shrouds about the first and second stage bucket tips, the thermal medium being provided from a source of heating/cooling fluid independent of the turbine. Access is provided to the rotor and turbine buckets by removing the outer and inner shell sections.

Removable inner turbine shell with bucket tip clearance control

A zero running clearance system for gas turbine engines includes a gas turbine engine compressor (14) having one or more first rotor assemblies (30) and one or more first stator assemblies (28) disposed adjacent the one or more first rotor assemblies (30); a gas turbine engine turbine (18) having one or more second rotor assemblies (104) and one or more second stator assemblies (102) disposed adjacent the one or more second rotor assemblies (104); one or more shroud segments (80) having blade seal surfaces (120) disposed radially outside of the tips of blades of both the first and second rotor assemblies (30;104) and a clearance distance extending between the blade tips and blade seal surfaces; and, an actuator (58) selectively operable to axially move the first and said second rotor assemblies (30;104) to alter the clearance distance.

Gas turbine engine blade tip clearance apparatus and method

A casing for the fan section of an aircraft gas turbine engine of the turbofan type. The casing includes an inner filler material and is defined by an outer shell and an inner liner that is spaced radially inwardly from the outer shell. The inner liner is held in position relative to the outer shell by a plurality of radially-inwardly-extending support pins. The pins are carried by the outer shell and are slidably received in and extend at least partially into the inner liner. The support pins retain the inner liner against axial and rotational movement relative to the outer shell, while allowing relative radial movement therebetween in response to thermal expansion and contraction, as well as in response to aircraft maneuver loads imposed on the engine.

Fan casing liner support

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.

Turbine inner shroud and turbine assembly containing such inner shroud

A method of operating a gas turbine engine is provided. The gas turbine engine includes at least one engine casing and at least one rotor assembly. The method includes directing airflow through a supply pipe and into a heat exchanger, lowering the temperature of the airflow in the heat exchanger, and directing the cooled airflow into the engine casing to cool the casing.

Methods and apparatus for maintaining rotor assembly tip clearances

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. The cylinder is operable for actuating the positioning mechanisms to move solely to one or the other of the inner and outer stops and cause the shroud segment to move solely to one or the other of the inner and outer positions thereof to corresponding solely provide one or the other of the minimum and maximum clearances between the shroud segment and rotor blade tips.

Wu-Yang Tseng

Papers

Blade tip clearance control apparatus using shroud segment position modulation

Blade tip clearance control apparatus for gas turbine engines

Vorrichtung zur laufschaufelspitzenspaltbreitensteuerung mittels mantelringsegmentpositionsbeeinflussung