Orbital Engine animation of two crankshafts geared together by an idler gear to rotate in unison with vanes in the rotor

 

Orbital Engine animation of two crankshafts geared together by an idler gear to rotate in unison with vanes in the stator

Orbital Engine animation with three crankshafts with vanes in the rotor

Orbital engine animation with three crankshafts with the vanes in the stator

Wankel Rotary Engine

Two Stroke petrol engine