A POWER TRANSMISSION DEVICE FOR A GAS TURBINE ENGINE, AN AEROPLANE AND A METHOD FOR OPERATING A GAS TURBINE ENGINE

摘要

The invention relates to a power transmission device (2) for a gas turbine engine (1) comprising a low pressure shaft (11) and a high pressure shaft (10), wherein the high pressure shaft (10) is arranged concentric to the low pressure shaft (11). The device further comprises an accessory unit (12) comprising at least one electric machine (29,30) adapted for a gas turbine engine starting operation and for generating electrical power. The power transmission device (2) further comprises a transmission unit (13) operatively connected to the low pressure shaft (11) and adapted for power transmission from the low pressure shaft (11) to the accessory unit (12). The transmission unit (13) comprises a gear changing mechanism (14) adapted to change between at least two gears for transmitting power from the low pressure shaft (11) to the accessory unit (12) over substantially the complete operational speed range of the low pressure shaft (11).