In this paper the authors establish the calculus expression of the volume flow rate for a new type of working machine that can work as pump, fan or low pressure compressor.The calculation of volumetric efficiency is established for a new type of machine.The results of the experimental research on the influence of the speed on the volumetric flow rate of the machine are exposed.

The first part of the paper presents the constructive solution for a new type of volumetric meter for liquid flow rate measurement. The meter consists of two special profiled rotors, which ensure a high accuracy in measuring the liquid flow rate. Mathematical computing relations for the rotor contour in (xi yi) coordinates are presented; a computer program has been used afterwards to obtain these coordinates necessary to build the rotors using a numerical controlled center (N.C.C.).

The paper presents a new type of machine that can be used as well as working machine or as force machine. The machine consists of two purpose-machined rotors that rotate with the same speed inside a casing; relations used for the computation of machine flow rate and power are presented, as well as results of experimental researches performed for an experimental model tested on a setup.