rotary engine

rotary engine internal-combustion engine whose cycle is similar to that of a piston engine, but which produces rotary motion directly without any conversion from reciprocating motion. A major problem associated with engines of this type is preventing the leakage of combustion gases. The only type of rotary engine currently considered to be of practical value is the Wankel engine (see internal-combustion engine ). Although the gas turbine produces rotary motion directly, it is not generally considered a rotary engine because it functions differently.

Wankel rotary engine Internal combustion engine with rotors instead of pistons, invented in the 1950s by German engineer Felix Wankel (1902–88). Each triangular rotor turns inside a close-fitting casing. Gaps between the casing and rotor form three crescent-shaped combustion chambers. Each chamber goes through a sequence of events similar to those in a four-stroke engine with pistons.