Rotary compressor and engine machine system

A rotary expansion device comprising:

• an outer housing containing a gas expansion chamber having an interior surface which surrounds a first axis;
• an outer hub assembly, disposed inside said gas expansion chamber of said outer housing and surrounding a second axis, which is offset from said first axis;
• an inner hub, disposed inside said outer hub assembly, and surrounding said first axis;
• a plurality of blades, each blade being pivotally coupled with said inner hub and extending radially therefrom, passing through said outer hub assembly to said interior surface of said outer expansion chamber, and being sealed at an end thereof with said interior surface of said gas expansion chamber of said outer housing, thereby forming a plurality of gas expansion compartments between said interior surface of said gas expansion chamber, said outer hub assembly, and respective pairs of blades, with the volumes of said gas expansion compartments varying as a function of rotative position of said blades about said first axis;
• a combustor external to said outer housing and being operative to produce a combustion gas which is supplied through an expansion gas inlet port to said gas expansion chamber for expansion in said plurality of compartments, so that said combustion gas is fed to successively adjacent ones of said compartments during rotation of said compartments about said first axis, and wherein said gas expansion chamber further includes an exhaust port from which an expanded combustion gas is vented subsequent to rotation of said compartments about said first axis from said expansion gas inlet port to said exhaust port;
• and
• a pressure vent between successively adjacent ones of said compartments, said pressure vent being operative to allow pressure in one of said successively adjacent ones of said compartments to be vented to another of said successively adjacent ones of said compartments.