Patent ID: 9631558
Date: 2017-04-25
CPC Classifications: F01D,F02C,F02K,F04D,F05D,Y02T

Claim:
1. A gas turbine engine comprising: a fan shaft driving a fan; a frame which supports said fan shaft; a plurality of gears to drive said fan shaft; a flexible support which at least partially supports said plurality of gears; a lower pressure turbine section providing a drive input into said plurality of gears; and a higher pressure turbine section, wherein said lower pressure 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 higher pressure 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 faster than the first speed, 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 about 0.5 and about 1.5; and said frame includes a frame lateral stiffness and a frame transverse stiffness, and said flexible support includes a flexible support transverse stiffness and a flexible support lateral stiffness, and said flexible support lateral stiffness being less than said frame lateral stiffness and said flexible support transverse stiffness being less than said frame transverse stiffness.