Abstract: A gas turbine engine having an electric generator includes a transmission shaft extending along a longitudinal axis of the engine and drivingly interconnecting a turbine shaft of the engine and a rotor shaft of the electric generator. The transmission shaft is engaged by splined mating connections with the turbine shaft and the rotor shaft. The transmission shaft has a shear neck defining a reduced radial wall thickness with respect to a remainder of the transmission shaft such as to provide a weakened region of the transmission shaft. An annular support structure, concentric with and surrounding the transmission shaft, is axially located between the shear neck and a forward end of the transmission shaft engaged to the turbine shaft, and includes a bearing operable to rotationally support the transmission shaft.

Abstract: An apparatus and method for connecting a fan rotor to a shaft of a gas turbine engine includes a segmented clinch nut plate having a plurality of clinch nuts installed in pre-drilled holes in each segment. A plurality of mounting bolts extending through the holes in the rotor shaft and holes in a mounting device of the shaft threadedly engage the clinch nuts of the clinch nut plate. The segments of the clinch nut plate are disposed separately one from another.

Abstract: A vane assembly for a gas turbine engine includes an annular shroud having openings therein and a plurality of vanes extending radially from the shroud and each having an extremity received within one of the openings. A grommet is positioned within each opening for shielding the vane extremity from the annular shroud. The grommet includes an annular protrusion for providing sealing between the opening and the vane extremity, and an annular restraint element adjacent the protrusion for retaining the vane in place relative to the shroud.

Abstract: A turbine case cooling system and a method for supplying a cooling gas flow are provided. The cooling system has a turbine case and a turbine case cooling manifold. The cooling system also has a fluid or cooling conduit. The cooling conduit has an inlet in fluid communication with the bypass duct, and an outlet in fluid communication with the cooling manifold. The cooling conduit also has an ejector section which in use supplies a motive air flow radially into the cooling conduit to draw a bypass air flow from the bypass duct. The motive air flow mixes with the bypass air flow to form the cooling gas flow. The cooling conduit also has a diffuser section which in use conveys the cooling gas flow toward the outlet in a direction substantially perpendicular to the center axis of the gas turbine engine.

Abstract: A bleed valve having a piston with a sealing member, the piston being displaceable between a first position to seal an aperture of a fluid conduit and an opposed second position spaced apart from the aperture to allow the working fluid therethrough. The bleed valve also has a guiding assembly with at least one guide wheel mounted to the piston and being displaceable therewith along a guide rail. The guide wheel has a guide groove extending inwardly from an outer rolling surface. The guide rail has a rail surface with a guide protrusion. The guide groove and the guide protrusion are complementary and in rolling contact with one another. The bleed valve also has a displacement mechanism for displacing the piston between the first and second positions. A compressor with a bleed valve and method for controlling bleeding of a working fluid are also discussed.

Abstract: A method of assembling a starter/generator in a gas-turbine engine, including coupling a rotor and a stator of the starter/generator such that the rotor is rotatable with respect to the stator to drive the rotor when the starter/generator is electrically powered and to produce electrical power when the rotor is rotated, securing the stator to a bearing support, coupling the starter/generator to a low pressure shaft of the engine by installing the bearing support over a bearing assembly secured to an end of the low pressure shaft, inserting the low pressure shaft through a high pressure shaft of the engine with the end of the low pressure shaft protruding therefrom and positioning the starter/generator in proximity of an end of the high pressure shaft, and drivingly engaging the rotor to the high pressure shaft.

Abstract: A gas turbine engine having at least one spool assembly, the at least one spool assembly including a fan rotor, a compressor disposed downstream of the fan rotor, a turbine and a shaft connecting the fan rotor, compressor and turbine, a joint affixed to an upstream end of the shaft, and including a first link connecting the fan rotor to the shaft and a second link connecting the compressor to the shaft, the second link being less rigid then the first link.

Abstract: A connector assembly for variable inlet guide vanes in a compressor case of a gas turbine engine comprises an annular case insert having a plurality of circumferentially distributed open-ended receptacles. The annular case insert is sized so as to be received inside a compressor case, with the plurality of circumferentially distributed open-ended receptacles being in register with holes in the compressor case. Bushings have an outer diameter sized to be received in a respective one of the receptacles of the annular case insert, and an inner diameter adapted to receive a connector portion of a vane. Sets of the bushing and the connector portion of a vane in one of the receptacles forming a rotational joint. A method for installing vanes in a compressor case is also provided.

Abstract: A gas turbine engine recuperator system includes a heat recuperator positioned in a gas turbine exhaust gas duct for recovering heat from turbine exhaust gases to preheat a compressor flow being supplied to the combustor. A continuous bleed flow of the turbine exhaust gases is provided to bypass the heat recuperator. The continuous bleed flow of the turbine exhaust gases is adjustable to reduce turbine exhaust gas pressure loss at a high engine operation level and to provide efficient heat recovery at low and/or medium engine operation levels.

Abstract: A method of assembling an electromechanical device in a gas-turbine engine, including mounting a rotor of the device on a rotor support, securing a stator of the device to a stator support, coupling the rotor support to the stator support such that said rotor is rotatable about said stator, securing the device to a bearing support, securing a bearing assembly on the low pressure shaft, coupling the device to the low pressure shaft by installing the bearing support over the bearing assembly, and drivingly engaging the rotor support to the high pressure shaft.

Abstract: A method of manufacturing a recuperator segment uses metal tubes deformed into air cells in a waved configuration. The air cells are stacked one to another to form a double skinned recuperator segment providing cold air passages through the respective air cells and hot gas passages through spaces between adjacent air cells.

Abstract: A vane assembly of a gas turbine engine includes a plurality of circumferentially spaced vanes extending radially between an outer case and an inner case. A spring-tensioned stator restraining strap is provided around the outer case and surrounding outer ends of the respective vanes. The outer ends of the vanes are received in corresponding openings defined in the outer case and project radially outwardly from the outer case. The spring-tensioned strap compresses the respective vanes radially and inwardly in position.

Abstract: A method of fabricating an inlet assembly for a gas turbine engine, the method including defining an intake duct of the inlet assembly between first and second space apart inlet case portions, locating at least one strut across the intake duct, each strut having a proximal end made integral to the first inlet case portion and an opposed distal end engaged in a respective strut-receiving aperture defined through the second inlet case portion, while maintaining the distal end of each strut in the respective strut-receiving aperture, adjusting the relative position of the first inlet case portion and the second inlet case portion until a predetermined throat dimension of the intake duct is obtained, and locking the adjusted relative position by attaching the second inlet case portion to each strut. An inlet assembly and gas turbine engine with inlet assembly as also disclosed.

Abstract: A casing for an aircraft turbofan bypass engine includes an outer ring, an inner hub and a plurality of struts radially extending therebetween. An annular portion of an engine core casing having an outer wall and an inner wall, is disposed between the outer ring and inner hub, forming an annular splitter supporting an upstream splitter tip structure. The annular splitter further includes an intermediate wall disposed in the annular splitter fixed to the outer wall and the struts, to distribute loads from the annular splitter box to the struts.

Abstract: An assembly for a gas turbine engine, with a gearbox including a first portion having a first input gear coupled to a rotatable turbine shaft, a first output gear, and defining a first transmission path between the first input and output gears, and a second portion having a second input gear coupled to the turbine shaft, a second output gear, and defining a second transmission path between the second input and output gears different from the first transmission path. A fan rotor is coupled to the first output gear and a booster rotor is coupled to the second output gear on a same side of the gearbox than the coupling between the fan rotor and the first output gear. A method of assembling a drive for a fan rotor and a booster rotor in a gas turbine engine is also disclosed.

Abstract: A method of applying a nanocrystalline metal coating to a titanium or titanium alloy blade of a gas turbine engine is described. The method includes selecting an intermediate bond coat from the group consisting of nickel, nickel alloy, P, B, Tl and combinations thereof, and applying the intermediate bond coat to at least a portion of the blade. A nanocrystalline metal coating having an average grain size of between 10 nm and 500 nm is then applied to the portion of the blade overtop of the intermediate bond coat.

Abstract: A fan and shaft assembly for a turbofan gas turbine engine comprises a shaft and a fan. Sets of aligned throughbores are respectively of the shaft and the fan, at a junction between the shaft and the fan. Fastening systems are provided for the sets of aligned throughbores. Each fastening system comprises a sleeve received in one of the sets of aligned throughbores and sized to fit without play in the set of aligned throughbores. A head of the sleeve abuts a surface at the junction between the shaft and the fan. A fastener is inserted in the sleeve and extends beyond both ends of the sleeve to clamp the fan to the shaft, the fastener being loosely received in the sleeve. A method for replacing a component of a fastening system retaining a fan to a shaft is provided as well.

Abstract: A method of applying a nanocrystalline coating to a gas turbine engine component is described. The method comprises the steps of applying an intermediate bond coat to at least a portion of the component, and then applying the nanocrystalline coating to at least the portion of the component overtop of the intermediate bond coat. The component may include, for example, a blade of which a dovetail portion of the blade root is protected by applying the intermediate bond coat and the nanocrystalline coating thereto.

Abstract: A recuperator disposed in the exhaust duct of a gas turbine engine includes a plurality of recuperator plates arranged in a spaced-apart relationship to define therebetween a plurality of interstices and fluid channels, the plurality of interstices adapted to direct therethrough at least one first stream received at a leading plate edge of the recuperator plates and the plurality of fluid channels adapted to direct therethrough at least one second stream to effect heat exchange between the at least one first stream and the at least one second stream. Each recuperator plate includes, formed at the leading plate edge thereof, a first concavity extending along the leading edge in a direction substantially parallel to a longitudinal axis of the plate. The first concavity extends transversely to a direction of the at least one first stream flowing over each recuperator plate.

Abstract: A method of assembling an electromechanical device in a gas-turbine engine, including mounting a rotor of the device on a rotor support, securing a stator of the device to a stator support, coupling the rotor support to the stator support such that said rotor is rotatable about said stator, securing the device to a bearing support, securing a bearing assembly on the low pressure shaft, coupling the device to the low pressure shaft by installing the bearing support over the bearing assembly, and drivingly engaging the rotor support to the high pressure shaft.