Patent ID: 9540948
Date: 2017-01-10
CPC Classifications: F01D,F02C,F02K,F04D,F05D

Claim:
1. A gas turbine engine comprising: a fan; a compressor section in fluid communication with the fan; a combustion section in fluid communication with the compressor section; a turbine section in fluid communication with the combustion section, wherein the turbine section includes a fan drive turbine section and a second turbine section, said fan drive turbine section driving said fan through a gear reduction; wherein said fan drive turbine section has a first exit area at a first exit point and is configured to rotate at or below a first speed, wherein said second turbine section has a second exit area at a second exit point and is configured to rotate at or below a second speed, which is higher than the first speed, and said first and second speeds being redline speeds, wherein a first performance quantity is defined as the product of the first speed squared and the first area, wherein a second performance quantity is defined as the product of the second speed squared and the second area; wherein a ratio of the first performance quantity to the second performance quantity is between 0.5 and 1.5; said second turbine section driving a first shaft, and said first shaft being mounted on a bearing, said bearing being mounted on an outer periphery of said first shaft at a location upstream of a point where the first shaft connects to a hub carrying turbine rotors associated with said second turbine section, with said location being downstream of said compressor section.