Experimental Research and Mathematical Modeling of Scroll Machine in Air Motor Mode

Abstract

Recently the scroll machine is widely used in air and refrigeration compressors, vacuum pumps, because it has a small number of moving parts, high efficiency and low level of noise. The volumetric rotary scroll machine is reversible and can function in air motor mode without any significant construction modification. Scroll air motor is a relatively new concept of pneumatic actuators. There is no technical data comparison with traditional air motors which now on the market. In this paper we describe the experimental bench for determining mechanical and flow performance of scroll air motor under different value of inlet pressure, mechanical losses and exergy efficiency. Mathematical model contains geometrical description of the involute scrolls, chamber volumes, radial and tangential leakage areas as a function of orbital angle; thermodynamical pressure and temperature differential equations of compressed air; and equation of mechanical torque balance on motor shaft. The results of experiments and mathematical modeling are presented and analysed. In the last part of the paper the performances of scroll air motor are compared with such performances of traditional radial and axial piston, vane, turbine air motors.