Adaptive fan system for a variable cycle turbofan engine

摘要

An adaptive fan system for a variable cycle turbofan engine having at least one turbine, includes a shaft structured to receive mechanical power from a turbine in the variable cycle turbofan engine and a first fan stage that is coupled directly to the shaft and is driven directly by the shaft. A transmission system is coupled to the shaft and a second fan stage is coupled to the shaft via the transmission system and is driven by the shaft via the transmission system. The transmission system is structured to selectively vary a speed between high and low speeds at which power is supplied from the shaft to the second fan stage relative to at least one of the shaft and the first fan stage, wherein the first fan stage and the second fan stage are configured to rotate in the same direction and at the same high speed to increase the mechanical power of the turbine.

主权项

1. A gas turbine engine, comprising;
a compressor structured to compress an airflow received at the compressor and to output the compressed airflow as a compressor discharge airflow; a combustor in fluid communication with said compressor, said combustor being structured to combust a mixture of a fuel and at least some of said compressor discharge airflow to generate a hot working airflow; a turbine in fluid communication with said combustor, said turbine being configured to extract a mechanical power from said hot working airflow; a shaft coupled to said turbine, said shaft being configured to receive and transmit said mechanical power from said turbine; a first rotating load powered by said shaft; a second rotating load powered by said shaft, wherein the first rotating load and the second rotating load rotate in the same direction; and a transmission system including:
a geartrain coupled to said shaft;a clutching mechanism coupled to said shaft in parallel to said geartrain, wherein said clutching mechanism includes a clutch and a positive locking mechanism disposed axially aft in relation to the clutch, wherein the second rotating load is disposed forward of the clutch, wherein the clutch couples the shaft to the second rotating load through alternating engagement of one of the positive locking mechanism and the geartrain such that when the positive locking mechanism is engaged the second rotating load is driven by the shaft at a same speed as the first rotating load and when the geartrain is engaged the second rotating load is driven at a speed less than the speed of the first rotating load, said transmission system being structured to selectively vary a speed at which power is supplied from said shaft to said second rotating load relative to a speed of at least one of said shaft and said first rotating load, wherein to increase extraction of mechanical power the second rotating load rotates at a same speed as the first rotating load.