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), and a wear resistant coating (40, 42, 60, 61, 82, 92). 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 (12-1, 12-2). Each of said rotors (14, 16) has helical lobes (14-1, 16-1) and intervening flutes (14-2, 16-2). The rotors (14, 16) have contact bands whereat torque is transmitted from one rotor (14,16) to another rotor (16, 14). The wear resistant coating (40, 42, 60, 61, 82, 92) is disposed on the contact bands of said rotors (14, 16).