The working principle of the air pump is: the engine drives the air pump crankshaft through two V-belts, thereby driving the piston to pump air, and the pumped gas is introduced into the air reservoir through the air guide tube. On the other hand, the gas storage tube introduces the gas in the gas storage tube into the pressure regulating valve fixed on the gas pump through a gas tube, thereby controlling the air pressure in the gas storage tube.

When the air pressure in the air storage cylinder does not reach the pressure set by the pressure regulating valve, the gas entering the pressure regulating valve from the air storage cylinder cannot open the pressure regulating valve valve; when the air pressure in the air storage cylinder reaches the pressure set by the pressure regulating valve , The gas that enters the pressure regulating valve from the gas tank opens the pressure regulating valve valve, enters the air passage in the air pump communicating with the pressure regulating valve, and controls the air inlet of the air pump to be normally open through the air passage.

Thus, the air pump can be operated with no load to reduce power loss and protect the air pump. When the air pressure in the air storage cylinder is lower than the pressure set by the pressure regulating valve due to loss, the valve in the pressure regulating valve is returned to the position by the return spring, the control air circuit of the air pump is disconnected, and the air pump starts pumping again.