Loose-proof structure of a filter cartridge shell

A loose-proof structure of a filter cartridge shell, comprising:

• a filter cartridge shell body, which has an open end comprising several threads;
• an upper end cover, which has a raised rafter edge, wherein said raised rafter edge is pressed with an upper surface of said open end;
• a loose-proof fixed ring, wherein said raised rafter edge of said upper end cover and said open end of said filter cartridge shell body are coupled with said loose-proof fixed ring;
• at least one loose-proof locking tooth, provided on a periphery surface of said raised rafter edge, wherein correspondingly, at least one loose-proof tooth space is provided on an inside surface of said loose-proof fixed ring contacting with the periphery surface of said raised rafter edge and matches with said loose-proof locking tooth;
• and
• at least one loose-proof scab, provided on an external end surface of said open end, wherein correspondingly, said loose-proof fixed ring has at least one loose-proof groove on a bottom of said loose-proof fixed ring, which matches with said loose-proof scab.