How The Rotary Engine Works
The Rotary engine functions in a way that is fundamentally different from conventional internal combustion engines. The piston is in fact a rotor that spins in the centre of a housing that is shaped like an oval pinched slightly in the middle. The Rotor has a set of internal gear teeth cut into the centre of one side. These teeth mate with a gear that is fixed to the housing. The gear mating determines the path and direction the Rotor takes through the housing.
The eccentric shaft is turned by the Rotors in a way similar to a handle turning a winch. With every 360-degree turn of the Rotor, the output shaft turns three times. The Rotor itself is triangular shaped, and its three points are in constant contact with the housing wall through an apex seal. The shape of the housing ensures that the Rotor’s centre point forms a closed circle with every complete turn. The three flanks of the Rotor combined with the inner surface of the housing form three working chambers, whose volume constantly changes during a single turn of the Rotor. This architecture makes a traditional crankshaft and values unnecessary. The only moving parts are the Rotary piston itself and the eccentric shaft. These characteristics mean that a Rotary engine is lighter and more compact than a traditional reciprocating engine.
While a normal four-cycle piston engine needs four cycles to facilitate two turns of the crankshaft, Rotary engines achieve all four cycles with only one turn of the Rotor. The Rotor itself produces the power of the Rotary engine and applies it to the eccentric shaft, which fulfils a function comparable to the crankshaft of a traditional piston engine.