Rotary engine

The invention provides a rotary engine, and belongs to the technical field of engines. The method solves the technical problems that an existing engine is low in heat energy conversion efficiency andthe like. An upper rotary chamber and a lower rotary chamber of a main body of the rotary engine are separated by a partition plate provided with a through hole, the upper rotary chamber and the lowerrotary chamber are both provided with two pistons, the upper piston and the lower piston are coaxially arranged and are opposite in rotation direction, the rotating directions of the two adjacent pistons are opposite, the side surfaces of the two pistons are in contact sealing, at least one pair of adjacently arranged grooves and a convex block is arranged on the side wall of each piston, the outer side surface of the convex block can abut against the inner side wall of the upper rotary chamber or the inner side wall of the lower rotary chamber to form a relatively sealed cylinder cavity, when the piston of the upper