Reduction of Quasi-impulsive Forces and Noise Emission in Three-screw Pump Rotors

In this paper a theoretical study is presented about the possibility of reducing the quasi-impulsive load compo-nents, which act on the rotors of the three-screw pumps in the rotational axial direction. These forces can be relat-ed, on the basis of previous experimental and analytical studies by the same authors, to the noise emission of the pump. The analysis is carried out by the systematic variation of one of the design parameters of the rotors, i.e. the semi-amplitude of the threaded zone of the screws, by using the analytical tools previously set-up for the study of the dynamic loads on the standard rotors. Finally, it is shown that a suitable choice of this design parameter on one hand allows to cancel the quasi-impulsive load, on the other hand has a positive effect on the loads on the cross section.