Patent ID: 8887487
Filing Date: 2014-11-18
Classification: F02C,F02K,F05D,Y02T

Abstract:
1. A gas turbine engine comprising: a compressor section; a combustor in fluid communication with the compressor section; a turbine section in fluid communication with the combustor, the turbine section including a fan drive turbine and a second turbine, the fan drive turbine including a plurality of turbine rotors; a fan including a plurality of blades rotatable about an axis and a ratio between the number of fan blades and the number of fan drive turbine rotors is between about 2.5 and about 8.5; and a speed change system driven by the fan drive turbine for rotating the fan about the axis, the speed change system comprising a gear box including a sun gear driven by a first shaft of the fan drive turbine at a speed of the fan drive turbine and an output that drives the fan, wherein the fan and the fan drive turbine both rotate in a first direction about the axis; wherein the fan drive turbine includes a first aft rotor attached to the first shaft and the second turbine includes a second aft rotor attached to a second shaft, wherein a first bearing assembly is disposed axially forward of a first connection between the first aft rotor and the first shaft, and a second bearing assembly is disposed axially aft of a second connection between the second aft rotor and the second shaft, and a power density is greater than about 1.5 lbf/in