Patent ID: 7585148

Claim:
A hollow-shaft rotor for a turbo-engine, comprising: a first shaft section arranged coaxially with a rotational axis of the engine having a first end surface and formed from a plurality of abutting first section disks; a second shaft section arranged coaxially and downstream of the first shaft section having a second end surface and formed from a plurality of abutting second section disks wherein the first and second end surfaces face each other; and a third shaft section arranged coaxially with and between the first and second shaft sections wherein the third shaft section comprises a plurality of axially abutting ring segments, each segment having an I-shaped cross section with: a web section extending in a radial direction having a radially outer end and a radially inner end, an upper flange section extending from the radially outer end of the web in an axial direction toward both the first and second end surfaces, and a lower flange section extending from the radially inner end of the web in the axial direction toward both the first and second end surfaces, wherein a shaft cavity formed between the radially inner and radially outer flanges where two or more adjacent ring segments join, and a second shaft cavity bounded by the inner diameter surfaces of the lower flange sections and the first and second end surfaces.