Piston, combustion chamber and gas machine

The piston comprises a piston body, a piston pit and a spiral groove, the piston pit is arranged at the top of the piston body, and the spiral groove is spirally arranged in the piston pit so as to drive mixed gas to form vortex motion. In the compression process of the piston, tumble motion moving in the tumble direction exists between one air channel and the other air channel, and the tumble motion is broken into small-scale vortex motion and turbulent motion at the position close to a compression top dead center, so that turbulence energy needed by ignition combustion is provided. When the piston moves upwards, the spiral groove forms vortex motion in the direction of the spiral groove, and when the spiral groove is compressed to the top dead center position, the vortex motion is kept under the action of the spiral groove, so that the uniformity of turbulence energy distribution is improved. The mixed gas promotes flame development to diffuse towards the edge of the combustion chamber in the later stage of