SCREW MACHINE

摘要

A screw machine (10) is provided. The screw machine (10) comprises a rotor housing (12), a conjugate pair of intermeshing rotors (14, 16), an outlet casing (13), and a conformable coating (44, 64). The rotor housing (12) has a pair of parallel, overlapping bores (12-1, 12-2). The conjugate pair of intermeshing rotors (14, 16) are located in said bores, each of said rotors having helical lobes (14-1, 16-1) and intervening flutes (14-2, 16-2). The outlet casing (13) is disposed at a discharge end of said rotor housing (12). Each of said rotors (14, 16) has a discharge end (14-4, 16-4) facing said outlet casing (13). The conformable coating (44, 64) is disposed between said discharge ends(14-4, 16-4) of said rotors (14, 16) and said outlet casing (13). The coating (44, 64) is at least one of iron phosphate, magnesium phosphate, nickel polymer amalgams, nickel zinc alloys, aluminum silicon alloys with polyester, and aluminum silicon alloys with polymethylmetacrylate (PMMA), or other materials that yield elastically when a force is applied to the coating. Preferably there is further provided a member (90) located intermediate said discharge ends (14-4, 16-4) of said rotors (14, 16) and said outlet casing (13). The member (90) has a surface facing said discharge ends of said rotors. The conformable coating (92) comprising a coating disposed on said surface of said member (90). In another preferred embodiment, the conformable coating (44, 64) comprises a coating on the discharge ends (14-4, 16-4) of said rotors (14, 16) or on said outlet casing (13).