Air filter is a component that filters out dust and impurities from the air. The filtered clean air enters the screw rotor compression chamber for compression. Since the internal clearance of the screw machine allows only particles of 15 microns or less to pass through, if the air filter element is blocked or damaged, a large amount of particles larger than 15 microns will enter the screw machine circulation. This not only greatly shortens the service life of the oil filter element and oil separator filter element but also leads to a large number of particles directly entering the bearing chamber, accelerating bearing wear, increasing rotor clearance, reducing compression efficiency, and even causing rotor seizure.