Patent ID: 6450758
Filing Date: 2002-09-17
Classification: F01D,Y02T

Abstract:
In a gas turbine having a rotor rotatable about an axis including a plurality of turbine wheels mounting turbine buckets, a rotatable bore tube assembly having elongated outer and inner tubes spaced from one another and concentric about said axis defining first and second passages for respectively conveying a cooling medium in one axial direction to the buckets of at least one of said turbine wheels and conveying spent cooling medium in an axial direction opposite said one direction to a return, and an aft shaft about said bore tube assembly and rotatable therewith, and a bearing about said aft shaft, a cooling system for cooling the bearing, including an axially extending cooling passageway concentrically about said bore tube assembly between said outer tube and said aft shaft and radially inwardly of said bearing, said system including an inlet for admitting a cooling fluid into said passageway for flow past said bearing and an outlet for receiving the cooling fluid whereby the cooling fluid cools said bearing, said turbine having a plurality of stages forming a hot gas path, said cooling fluid outlet lying in communication with said hot gas path downstream of said stages.