Structure: Low-temperature air heat engine model-magnetic coupling is a single-rod structure, and the power cylinder is at the center of the upper end cover of the hot cylinder. The flywheel pillar is made of cylindrical aluminum alloy, the thickness of the flywheel is 3mm, the power piston is aluminum alloy, there is a top wire fixing magnet inside, the piston in the hot cylinder is made of density sponge, and the pillar and the flywheel are connected by high-precision bearings. A cup of hot water can be used as a heat source to start the model operation. This model is in the form of loose parts, exercises hands-on ability, and the metal structure can be repeatedly disassembled and assembled.