Many types of rotary combustion engine, like the Quasiturbine or the Wankel engine, have been devised [1], all having the same basic concept; to avoid the reciprocating motion of the piston with its inherent vibration and rotational-speed-related mechanical stress. Sometimes these engines are referred to in somewhat erroneous shorthand as rotary engines, although the term rotary engine was first used to describe the rotary piston engine, a type of aircooled reciprocating aircraft engine, where in the reverse of the usual piston engine practice, the crankshaft is static and attached to the airplane, while a bank of cylinders rotate around the crankshaft and are attached to the propeller.
