Abstract: A gas turbine engine apparatus includes an engine flowpath, a protuberance and a variable vane. The protuberance projects into the engine flowpath. The variable vane extends across the engine flowpath. The variable vane includes a pivot axis and an airfoil. The variable vane is configured to pivot about the pivot axis between a first position and a second position. The airfoil extends spanwise along a span line between a first end and a second end. The airfoil extends chordwise along a chord line between a leading edge and a trailing edge. A recess extends spanwise into the airfoil from the first end. The airfoil, at the first end, is spaced from the protuberance when the variable vane is in the first position. The airfoil, at the first end, is aligned with the protuberance and the protuberance projects into the recess when the variable vane is in the second position.

Abstract: A gas turbine engine apparatus includes an engine flowpath, a protuberance and a variable vane. The protuberance projects into the engine flowpath. The variable vane extends across the engine flowpath. The variable vane includes a pivot axis and an airfoil. The variable vane is configured to pivot about the pivot axis between a first position and a second position. The airfoil extends spanwise along a span line between a first end and a second end. The airfoil extends chordwise along a chord line between a leading edge and a trailing edge. A recess extends spanwise into the airfoil from the first end. The airfoil, at the first end, is spaced from the protuberance when the variable vane is in the first position. The airfoil, at the first end, is aligned with the protuberance and the protuberance projects into the recess when the variable vane is in the second position.

Abstract: A variable guide vane (VGV) described herein includes an airfoil for interacting with a fluid inside a gas path of a gas turbine engine. The airfoil is mounted to a button and rotatable with the button about an axis. The button includes a platform surface defining part of the gas path adjacent the airfoil during use. The platform surface of the button includes a depression for receiving therein part of an adjacent VGV and providing clearance between adjacent VGVs at aggressive vane angles.

Abstract: A variable guide vane (VGV) described herein includes an airfoil for interacting with a fluid inside a gas path of a gas turbine engine. The airfoil is mounted to a button and rotatable with the button about an axis. The button includes a platform surface defining part of the gas path adjacent the airfoil during use. The platform surface of the button includes a depression for receiving therein part of an adjacent VGV and providing clearance between adjacent VGVs at aggressive vane angles.

Abstract: A gas path duct for a gas turbine engine comprises an gas path defined around a longitudinal axis between an inner shroud and an outer shroud. The gas path adapted to receive therein a variable-pitch vane mounted between the inner and outer shrouds. The variable-pitch vane adapted to be pivotable about a pivot axis extending across the gas path between an outer pivot point and an inner pivot point. A portion of at least one of the inner and outer shrouds defines a spherical surface having a concave shape facing the longitudinal axis and extending away from a corresponding one of the inner and outer pivot points. The spherical surface having a center positioned on the pivot axis and a radius equal to a distance, perpendicular to the longitudinal axis, between the longitudinal axis and the corresponding one of the inner and outer pivot points.