A micro diaphragm pump is a miniature vacuum pump equipped with an inlet and outlet nozzle, each housing an exhaust nozzle. A mechanical mechanism within the pump reciprocates the diaphragm, creating a continuous vacuum or negative pressure at the inlet and a slight positive pressure at the exhaust nozzle. The working medium is primarily gas, and the pump is a compact device. Micro diaphragm pumps operate in two modes. The following explains their working principles in detail.
1. A micro electric diaphragm pump uses a miniature DC motor (typically operating at 5V, 12V, or 24V) as a power source. This motor drives an internal mechanical eccentric mechanism, which in turn reciprocates the diaphragm. This compresses the air within the fixed-volume pump chamber (when compressed, the suction port is closed and the exhaust port is open, creating a slight positive pressure) and stretches it (when compressed, the exhaust port is closed and the suction port is open, creating a negative pressure). This creates a pressure differential between the vacuum pump's suction port and the ambient atmospheric pressure. This pressure differential forces (sucks) the air into the pump chamber and then out the exhaust port.
2. Microdiaphragm pumps use the rotation of the screw to suction and discharge liquids. The central screw in a microdiaphragm pump is the active screw, driven by the prime mover. The screws on either side are driven screws, rotating in the opposite direction of the active screw. The threads of both the active and driven screws are double-start. Due to the intermeshing of the screws and the tight fit between the screws and the inner wall of the liner, one or more sealed spaces are created between the suction and discharge ports of the microdiaphragm pump. As the screw rotates and meshes, these sealed spaces are continuously formed at the suction end of the vacuum pump, sealing the liquid in the suction chamber. The liquid is then continuously pushed from the suction chamber along the axial direction of the screw to the discharge end, and the liquid enclosed in each space is continuously discharged, just like a nut being continuously pushed forward when the thread rotates. This is the basic working principle of the micro diaphragm pump.