The motor (4) drives the diaphragm (2) on the left and right plunger through the gearbox (3) one after another to reciprocate. In both the left and right pump chambers, there are four one-way ball valves (1) up and down, the movement of the diaphragm causing a change in the volume in the working chamber, forcing the four one-way ball valves to open and close alternately, Inhaled and discharged.