SINE-WAVE-ROTOR ENGINE Russian patent published in 2008 - IPC F01B3/04 

FIELD: machine building.

SUBSTANCE: sine-wave-rotor engine incorporates housing accommodating cylinders, each furnished with combustion chamber, working gas feed and discharge ducts. The aforesaid cylinders house pistons with con-rods where gears running in roller bearings and interacting with sine-wave-rotor toothed surface are arranged, the rotor being fitted on the engine main shaft. Cylinders axes can be perpendicular or parallel to the said rotor axis. The said toothed surface can be arranged on the rotor inside or outside sides. The rotor can have three or more top and bottom dead centers. The cylinder outer side surface accommodates split rolling bearings pressed to the cylinder inner surface by thermally expanding rods. The rotor is furnished with a circular ledge on one its side provided with toothed surface and on the other one with a smooth surface mating sine-wave profile of the enveloping toothed surface. Note here that the con-rod of every piston is linked up with the roller interacting with the aforesaid smooth and spring-loaded towards the con-rod for it to be pressed against the rotor body.

EFFECT: reduced lateral loads exerted by pistons on cylinder walls, lower friction factor, increased number of piston working strikes per one revolution of engine main shaft, higher reliability.