ScrewCompressorneed tooverhaulthe host ScrewCompressorhostis running,betweenthe screwand thescrew, screw andbetweenthe hostshelland front and rearendarenotin contacttheory, the reasonis: Compressorrunningtimehostof the filmformedbetweenthe screwand thescrewdoes not directlycontactthe hostcoursein Compressorstartorstopjustshortfilmbecausefilmhas not yet formed, orthe stateis poor,betweenthe screwand thescrewthere will be somedirect contact;