Determining of actual profile clearances and screw compressor rotor positions depending on working conditions

Abstract

In general, screw compressor characteristics depend on their working chamber clearances. One of the main of clearances in the working chamber of screw compressors are the clearances between rotors’ profiles, which are produced due to a reducing of theoretical rotor profiles. This reducing is made to compensate thermal deformation, manufacturing errors and other negative factors, which occur during the screw compressor working cycles and may cause a rotors’ teeth interference. This also may result in a transmission error, which increases the rotor profile clearance on one side of rotor tooth and reduces on other. A screw compressor rotor gearing mathematical model which can predict the actual rotor position and value of the transmission error was developed. An analysis of compressor working conditions influence on the transmission error value is done. Results of the presented work are used for working process mathematical models for improving their accuracy. They also may be used as basis for development of reducing theoretical profiles methods with the aim to reducing of the rotor profiles’ clearances and improve screw compressor characteristics.