A pistonless rotary engine having a four faces articulated rotor with a free and accessible center, rotating without vibration or dead time, and producing a strong torque at low RPM under a variety of modes and fuels; Qurbine: The Quasiturbine can be used as an air motor, steam engine, Stirling engine, compressor and pump. The Quasiturbine is also an optimization theory for extremely compact and efficient engine concepts.

The Quasiturbine is at the crossroad of three modern engines. Inspired by the turbine, it perfects the piston, and improves upon the Wankel.

The Quasiturbine is universal in relation to energy sources: Liquid and gaseous fuel, hydrogen, steam, pneumatic, and hydraulic. The Quasiturbine engine was invented by the Saint-Hilaire family and first patented in 1996. The engine makes use of a complex computer calculated oval shape stator housing, creating regions of increasing and decreasing volumes as the rotor turns. It is capable of burning fuel using detonation, the optimal combustion mode of the future which the piston cannot stand.