Internal combustion engine

The utility model relates to an internal combustion engine, and belongs to heat engines. The internal combustion engine is mainly composed of an oil supply, lubricating, cooling and starting system and a valve mechanism. A cylinder block (6) is arranged around the periphery of an impeller (5), a wave-shaped curved-surface rail is arranged along the periphery of the upper surface of the impeller (5), the wave-shaped curved-surface rail is segmented according to 900 and comprises two wave crests and two wave troughs, the impeller (5) is arranged in a box (3), an upper cover (2) is arranged on the upper portion of the box (3), and a base (1) is arranged on the lower portion of the box (3); a power output shaft (4) is arranged at the center of the impeller (5), the power output shaft (4) is fixed on the upper cover (2) and the base (1) through bearings, the impeller (5) is in movable fit with the base (1), and a piston pin (13) is arranged on a piston (10) in the cylinder block (6); the piston pin (13) is provide