Quasiturbine

The Quasiturbine or Qurbine engine is a proposed pistonless rotary engine using a rhomboidal rotor whose sides are hinged at the vertices. The volume enclosed between the sides of the rotor and the rotor casing provide compression and expansion in a fashion similar to the more familiar Wankel engine, but the hinging at the edges allows the volume ratio to increase. A geometrical indetermination (not uniquely defined) of the Quasiturbine confinement stator shape allows for a variety of profiles (including asymetrical) and design characteristics. Unlike vane pumps, in which vane extension is generally important and against which the pressure acts to generate the rotation, the Quasiturbine contour seals have a minimal extension and the rotation does not result from pressure against these seals. Since the rotational force within the Quasiturbine comes from the pressure on the entire pivoting-blade, and not on an extensible vanes which impose a geometric back flow at chamber overlaps, the high eccentricity QT stators increases considerably the stroke displacement volumes which can exceed the whole engine volume per rotation. Such a high displacement to external engine volume ratio near unity leads to exceptional engine power density in volume and weight, while maintaining high torque. Patents for the Quasiturbine (in the most general AC concept with carriages) are held by the family of Gilles Saint-Hilaire of Québec. As well as an internal combustion engine, the Quasiturbine has been proposed as a possible pump design, and a possible Stirling engine. It has been demonstrated as a pneumatic engine using stored compressed air, and as a steam engine. There are at least four proposed designs: Two-port with carriages, suitable for use as an internal combustion engine. Four-port without carriages, suitable for use as a pneumatic engine or hydraulic engine, steam engine or pump. Two-port without carriages, a conceptual design which is hoped to combine some of the advantages of the existing two- and four-port prototypes.