Gas turbine engine with high speed low pressure turbine section and bearing support features

摘要

A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5. The high pressure turbine is supported by a bearing positioned at a point where the first shaft connects to a hub carrying turbine rotors associated with the second turbine section.

主权项

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.