Abstract: A positive-displacement turbine engine comprising two rotors, exhaust opening for discharging exhaust gas, intake opening for receiving air and fuel or air-fuel mixture, turbine channels, turbine shaft, plurality of turbine blades, and spark plug. The rotors share a single shaft and are positioned in the opposite sides of the combustion head. Each of the turbine channels has a constant depth and varying width and comprises an intake zone, compression zone, combustion-expansion power-stroke zone, and exhaust zone. Each of the turbine channels widens in the intake zone, narrows in the compression zone, widens in the combustion-expansion power-stroke zone, and narrows in the exhaust zone. The turbine blades maintain a constant lateral orientation while the two rotors rotate. Each turbine blade has a blade-rod with two ends and a downward-offset crank on one end of the blade-rod that maintains the turbine blade in a constant horizontal orientation during rotation of the rotors.

Abstract: The invention attains frictionless positive displacement by keeping its flat rectangular turbine blades constantly in lateral orientation throughout engine shaft rotation, the blades within a close-fitting combustion channel that accordingly widens and narrows so as to accomplish intake, positive compression, combustion, expansion and exhaust continuously during every rotation. The turbine blades are kept mutually parallel by means of an integral crank on every blade-supporting rod's opposite end, all cranks positioned by a disk constrained to rotate about an offset axis, in synchronism with the rotor. The invention operates at the rotational speed range of piston engines. Free of piston engines' gross internal sliding friction, therefore needing no cooling system, the invention will double the fuel economy of piston-powered automobiles, trucks and motor vessels. Light in weight, it can directly replace geared gas turbines in aircraft.