Patent attributes
A turbine engine arrangement includes an electrical machine that acts as a generator or motor. During initial start-up, the electrical machine acts as the motor to drive shaft rotation. The arrangement includes a compressor fan that generates an airflow utilized by an air turbine to drive the electrical machine as a generator. A duct directs airflow exhausted from the air turbine to a heat exchanger to exchange heat with a bypass flow from the compressor fan. In such circumstances, the generator can operate substantially independently of a rotational speed of the engine shafts within the core, whilst bled air through the valve acts to cool the electrical machine during initial start-up. A gearbox is provided for matching air turbine rotation with generator requirements whilst also allowing for connection to the primary drive shaft of the core to allow engine start-up or driving of the generator.
