A Study of the Single Screw Compressor Profile

Stable hydrodynamic lubrication film is needed between the tooth profiles for smooth running and long life ofa single-screw compressor. This lubrication film is easily established with "straight line enveloping screw pair" rotors, but this kind of engagement pair is very difficult to machine. In this paper it is suggested that 11 a conical surface two-envelope engagement pair '' be used as the single-screw compressor profile. The mathematical model, the working-surface characters, the structural characteristics and the machining method of this kind of engagement pair are elaborated. It has been proven by practice and experiment that this kind of engagement pair can be machined conveniently either in small or large quantities. SYMBOLS u axial position variable of conical surface, em 9 angle variable of conical surface, rad a,d2,d1a',E ,B,H const., em 0(, (3 const, rad " 1, tp2 , 91 , 9z. rotation angles, rad ~ 2 transmission ratio slide angle, rad relatively-sliding factor