The cylinders are evenly distributed with the axis of the compressor as the center, and the connecting rod connects the piston and the swing plate with a spherical universal coupling at both ends. The working principle of the compressor. This compressor is the same as the crankshaft connecting rod type, and has inlet and exhaust valves. , the working cycle also has four processes of compression, exhaust, expansion, and suction. Generally, a pendulum plate is equipped with five pistons, so that when the main shaft rotates once, the corresponding five cylinders have five exhaust processes.