Patent ID: 8919133

Claim:
A twin-spool gas turbine engine comprising: a low-pressure LP spool and a high-pressure HP spool, which spools are mounted so as to rotate about a same axis in a fixed casing, the low-pressure LP spool including a compressor and a turbine which are connected by a low-pressure LP shaft, the low-pressure LP shaft being supported by an upstream LP bearing, a first downstream LP bearing, and a second downstream LP bearing by the fixed casing, the high-pressure HP spool being supported by an upstream HP bearing and a downstream HP bearing, wherein the first downstream LP bearing is positioned between first portion of a journal at a downstream end of the LP shaft and a first portion of a hub of an exhaust casing, wherein the second downstream LP bearing is positioned between a second portion of the journal of the LP shaft and a second portion of the hub of the exhaust casing, wherein an outer diameter of the second portion of the journal is greater than an outer diameter of the first portion of the journal, and an inner diameter of the second portion of the hub of the exhaust casing is greater than an inner diameter of the first portion of the hub of the exhaust casing, wherein the downstream HP bearing is an inter-shaft bearing comprising an inner raceway secured to an HP turbine rotor and an outer raceway secured to the LP shaft, wherein a radial position of the downstream HP bearing is between a radial position of the first downstream LP bearing and a radial position of the second downstream LP bearing, and wherein the second downstream LP bearing is located upstream of the first downstream LP bearing.