Patent ID: 8893499

Claim:
A rotating machine, comprising: a hermetically-sealed housing having an expander rotor and a generator rotor rotatably arranged therein, the generator rotor being supported by one or more radial bearings and the expander rotor being a tubular shaft overhung off one end of the generator rotor and defining a chamber therein; an expansion device disposed within the housing and being configured to expand a working fluid to rotate the expander rotor and thereby drive the generator rotor; a generator disposed within the housing, axially-spaced from the expansion device and partially supported by the generator rotor; an extraction line fluidly coupled to an intermediate expansion stage of the expansion device and configured to extract working fluid therefrom; a first fluid line fluidly coupling the extraction line to the housing and being configured to introduce a first portion of extracted working fluid into the housing to cool the generator and the radial bearings; and a second fluid line fluidly coupling the extraction line to the chamber and being configured to introduce a second portion of extracted working fluid into the chamber to minimize unequal axial thrust loads.