Rolls-royce Corporation

Steven D Lawer

Mark A Halliwell

A seal segment ( ) as described for a seal segment ring ( ) of a turbine ( ) in a gas turbine engine ( ). The seal segment ( ) has an inner surface ( ) adapted to face the turbine blades ( ) in use. Path means ( ) is defined in the seal segment ( ). The path means ( ) is adapted to extend, in use, generally parallel to the principal axis of the turbine and has downstream inlet means ( ) through which a cooling fluid to cool the seal segment can enter the path means ( ) and upstream outlet means ( ) from which the cooling fluid can be exhausted from the path means ( ). The cooling fluid can flow along the path means ( ) in a generally upstream direction opposite to the flow of gas through the turbine.

Seal segment for a turbine

A sealing element ( ) for a turbine of a gas turbine engine includes a radially inner surface region provided with an integrally formed seal structure ( ) comprising a plurality of radially inwardly projecting walls ( ). The walls may be abradable and may define cells ( ) for receiving an abradable sealing material.

Abradable seals

A power turbine includes pivotable vanes for a variable area nozzle which are accurately and consistently assembled in a first full throat area position by providing an abutment and an abutment surface on gear segment arms attached to spindles at the radially outermost ends of the vanes. When the first vane has been fitted in the 100% throat position by threading its aerofoil portion through a slotted aperture in the turbine casing 10, the remaining vanes are accurately angularly positioned by causing their abutments to abut the abutment surface on the previously fitted vane segment arm.

Variable angle vane arrays

A power turbine includes a stage of pivotable nozzle vanes. The individual vanes are pivoted by connecting them to a toothed unison ring via actuating levers in the form of gear segments. The gear segments only have sufficient teeth to enable pivoting of the vanes between normal maximum and minimum operating angles. If an emergency closure of the nozzle is required, the unison ring pivots the gear therewith, whereupon pins on the unison ring engage projections on each segment, thus causing the segments to continue pivoting the vanes to a closed position.

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Derby, United Kingdom

Steven D Lawer