Abstract: A stator vane stage in a split-case, variable geometry axial flow compressor includes two 180-degree spoke-like arrays of stator vanes on upper and lower case halves of the compressor case and a pair of unitary, 180-degree arc shroud ring segments. Each stator vane has a pivot shaft at one end rotatably supported in a radial bore in the corresponding case half by a bushing and a cylindrical vane button at the other end. Each shroud ring segment has a corresponding plurality of cylindrical vane button sockets in an outer surface thereof which rotatably receives a corresponding vane button. The spoke-like array of the stator vanes rigidly positions the shroud ring segments relative to the compressor case.

Abstract: A gas turbine engine rotor having a turbine on a tubular shaft of the rotor and a compressor rotating group adapted for attachment to the shaft. The shaft has a radial flange at one end with an annular face in a plane perpendicular to the axis of the shaft and interrupted by a symmetrical array of bolt holes. The compressor rotating group has an annular face juxtaposed the annular face on the shaft and interrupted by a corresponding symmetrical array of bolt holes. An adjustable annular shim pack consisting of a pair of identical wedge-shaped annular shims is disposed between the juxtaposed annular faces and is adjusted by relatively rotating the shims until the wedge angle of the shim pack equals the angle between the planes of the annular faces when the longitudinal axes of the shaft and compressor rotating group are collinear. The compressor rotating group is bolted to the shaft with the shim pack captured between the juxtaposed annular faces.

Abstract: An oil system for a gas turbine engine including a supply circuit having a main pump supplied from a reservoir tank and discharging in bearing sumps of the engine, a scavenge circuit having a plurality of scavenge pumps supplied from the sumps of the engine and discharging back to the reservoir tank, and a distributing valve in the supply and the scavenge circuits operative when main pump discharge pressure is below a threshold pressure characteristic of main pump interruption to connect the scavenge pump discharge to the supply circuit so that residence oil in the supply circuit is recirculated to maintain bearing lubrication after main pump interruption.