The working principle of dry screw vacuum pump is to realize gas delivery and compression by periodically changing the inter-tooth volume through the opposite movement of a pair of asymmetric screw rotors. The specific process is divided into three stages: suction, compression and exhaust:
Intake process: When the rotor starts to rotate, the inter-tooth volume gradually expands, forming a vacuum, and the gas is sucked in under the action of the pressure difference. As the rotor continues to rotate, the inter-tooth volume continues to expand and remains connected to the suction orifice until the suction process ends.
Compression process: As the rotor rotates further, the inter-tooth volume begins to decrease, and the volume of the gas sealed therein also decreases, resulting in an increase in pressure, thereby realizing the gas compression process.
Exhaust process: When the inter-tooth volume is connected to the exhaust orifice, the gas with exhaust pressure is gradually discharged through the exhaust orifice until the gas in the inter-tooth volume is completely discharged.
