Rolls-Royce Corporation

Mark J Knight

John D Kernon

Richard S Booth

Richard Booth

The present invention provides a casing assembly for a gas turbine engine comprising a radially inner casing and a radially outer casing. The assembly further comprises an axial mounting arrangement for mounting the inner casing and outer casing in a fixed axial relationship. The axial mounting arrangement allows radial movement of the outer casing relative to the inner casing such that distortion of the inner casing as a result of engine carcass loads on the outer casing is obviated as the inner casing is radially isolated from the outer casing.

Casing assembly

A turbomachine aerofoil blade has an aerofoil body portion and a dovetail root fixing at the base of the aerofoil body portion which slides, in use, into a correspondingly shaped slot of a rotor of the turbomachine. The dovetail root fixing has a neck portion, and support flanks engage with matching angled surfaces of the slot under centrifugal loading of the aerofoil blade to support the aerofoil blade on the rotor. The neck portion is shaped such that a rotational adjustment of the aerofoil blade relative to its angular position when supported under centrifugal loading is needed to provide adequate clearance at the neck portion to allow the dovetail root fixing to slide into the slot. On centrifugal loading the engagement of the support flanks with the matching angled surfaces of the slot forces a reversal of the rotational adjustment and reduces the clearance at the neck portion.

Aerofoil blade

A sealing ring for controlling gas leakage through the annular space between two rotating concentric members; for example engine shafts. The sealing ring 20 has a generally trapezoidal cross section and an overlapping scarf joint. The sealing ring improves sealing by providing continuous lines of contact at edges between inner and outer coaxial shaft members.

Sealing ring for gas turbine engines

Conventionally gas turbine engine compressors have fixed inlet guide vanes to give a predetermined swirl to incoming air at an engine design speed, so that air enters the compressor at an optimum angle. At speeds much lower, for example, than the design speed the guide vane is less efficient. The guide vanes are thereby made variable in camber. Each vane comprises a number of spanwise hinged members which can be moved relative one to another to vary the vane camber.

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Derby, United Kingdom

Mark J Knight