Abstract: A rotational system for a miniature gas turbine engine includes a rotor shaft rotationally mounted to a forward bearing and an aft bearing. The rotor shaft is located axially with a single threaded rotor nut which provides an axial preload maintained by a fixed compressor wheel and spacers. A preload spring provides dynamic compensation for tolerance variation and undesirable axial movement during rotation of the shaft. A permanent magnet generator is mounted to the rotor shaft behind the forward bearing to generate electrical power for the engine and other accessories. The rotor shaft is inertia welded to a turbine wheel to form a cavity which provides a thermally conductive path away from the aft bearing. A seal ring mounted within a groove within the rotor shaft provides a pneumatic seal to further protect the aft bearing from thermal transfer between the turbine section and the compressor section.

Abstract: A thermal management system for a gas turbine engine includes a cooling airflow which enters through an air filter portion of a forward cover for filtration of particulate which may result in FOD to a rotational system of the engine. Filtered cooling airflow flows along a rotor shaft over and through a forward bearing, over and through a permanent magnet generator, then over and through an aft bearing to provide thermal management. Commensurate therewith, the cooling airflow atomizes and communicates a lubricant to the bearings. From the aft bearing, the cooling airflow merges with a primary airflow path from an intake which generally surrounds the forward cover.

Abstract: A static structure for a miniature gas turbine engine includes a forward housing, a forward cover, a diffuser housing, a diffuser, a turbine nozzle, a combustor liner, a combustor housing and an exhaust pipe with relatively uncomplicated assembly interfaces. The static structure defines airflow and lubrication passages which communicate lubricant and airflow to each shaft bearing such that an adequate measured quantity of lubricant is supplied to the bearings in response to engine speed. The airflow through the airflow passage carries the lubrication supplied to the forward bearing toward the aft bearing to further lubricate the aft hot section bearing.

Abstract: A thermal management system for a gas turbine engine includes a cooling airflow which enters through an air filter portion of a forward cover for filtration of particulate which may result in FOD to a rotational system of the engine. Filtered cooling airflow flows along a rotor shaft over and through a forward bearing, over and through a permanent magnet generator, then over and through an aft bearing to provide thermal management. Commensurate therewith, the cooling airflow atomizes and communicates a lubricant to the bearings. From the aft bearing, the cooling airflow merges with a primary airflow path from an intake which generally surrounds the forward cover.

Abstract: A turbofan engine includes a combined stage rotor mounted for common rotation with a shaft, a compressor stage, and a turbine stage. Each of the plurality of fan blades of the combined stage rotor are contiguous with a respective compressor blade. The combined stage rotor is located at a junction between a fan bypass duct and a core duct. The fan bypass stage portion includes a plurality of the fan blades which communicate incoming airflow into fan bypass airflow through the fan bypass duct. The compressor stage portion includes a plurality of the compressor blades which communicated airflow into core airflow through the core duct. The plurality of fan blades extend substantially perpendicular to the plurality of compressor blades such that the plurality of compressor blade portions extend at least partially into the core duct and preferably will include splitters for enhanced efficiency.

Abstract: A turbofan engine includes a combined stage rotor mounted for common rotation with a shaft, a compressor stage, and a turbine stage. Each of the plurality of fan blades of the combined stage rotor are contiguous with a respective compressor blade. The combined stage rotor is located at a junction between a fan bypass duct and a core duct. The fan bypass stage portion includes a plurality of the fan blades which communicate incoming airflow into fan bypass airflow through the fan bypass duct. The compressor stage portion includes a plurality of the compressor blades which communicated airflow into core airflow through the core duct. The plurality of fan blades extend substantially perpendicular to the plurality of compressor blades such that the plurality of compressor blade portions extend at least partially into the core duct and preferably will include splitters for enhanced efficiency.