JPS60216088A - Screw rotor - Google Patents

Abstract

PURPOSE:To keep of any reduction in efficiency in preventing a seal point from wearing, and also prevent abnormal vibration and noises from occurring, securing such operation as producing no overload, as well as to aim at simplification in cutting operations, by forming new profile female and male rotors in specific form. CONSTITUTION:Each both profile of male and female rotors 1 and 2 is formed into a specific form, and since the circular center of a radius R4 forming a tooth profile at the followed side of the male rotor 1 is situated in keeping apart far from a straight line connecting each rotation center of these rotors 1 and 2, a vacuum-forming space 18 to be produced in a contact part between these rotors 1 and 2 is made smaller. With this constitution, a power loss spent for the vacuum formation is well reducible, and a short circuit leakage space is also reducible, while an abnormal vibration and a noise to be produced in time of closing a discharge port just before termination of a discharge stroke and, what is more, a wedge effect is successful owing to lubricating oil so that improvements in lubricity and sealability are promotable, and furthermore a pressure angle in a profile curve can be made larger whereby machinability for the profile curve is excellent and simplification in hobbing is thus promotable.