The present dissertation addresses the design, construction, simulation and preliminary tests of an innovative positive displacement rotary compressor. A review is presented on the previous works, papers and dissertations, based on this new this new Kopelrot technology. A new prototype, employing a new driving system, was manufactured. The main feature of the machine is that, by adjusting the eccentricity between compressor cylinder and driving mechanisms axis, a variable capacity device is obtained. Design, manufacturing and assembly of components and subsystems of the compressor are presented in detail. Design data of the compressor allowed for a simple thermodynamic simulation model to be developed. Main conclusions of the simulation are that a full positive displacement compression cycle can be attained with the Kopelrot technology and that use of discharge and suction valves is required in order to have the compressor operating under different conditions.