The Mechanical Analysis of a Scroll Compressor

Based on thermodynamic and mechanical models. the axial and tangential forces acting on the orbiting scroll and their balance methods are discussed in this paper. Besides, a detailed analysis of orbiting mechanism of three Pins is carried out too. INTRODUCTION The advantageous characteristics of scroll compressor have been pr1>ved in theory and experiment [ 1 ] [ 3 ] in rer.ent years. Remarking the main influences of the axial and tangential forces acting on orbiting scroll on the performance and reliability, ~his paper puts forward a new balancing ~ethod and compares it with the balance means used. The mathematical model and computer program of scroll compressor working process [ 2 ] arr app] ied to the calculation of this paper.A proloLYPf! of scrol I for air condition has been developed and tr.sted by authors. The calculated results and experimental results are consistent THE AXIAL AND TANGENTIAL GAS FORCES ACTING ON ORBITING SCROLL ~ith crank shaft rotation, the center of orbiting scroll is ,pushed around lhe center of fixed scroll or crank shaft. As the gas in the sealed volumetric chambers. which are composed of the orbiting and fixed scroll. is compressed, the gas Pressure increases and the orbiting scroll is forced. With the thermodyamic mathmatic model [ 2 ] and the mechanical model. the gas force exerting model is shown in rig.l. In rig.] a). because the pushing force PN T of crank shaft and the tangential gas force P~ t arc not acted on the same point, thus makes the orbiting scroll rotate in itsself, the normal compression chambersare interfered, self·rotation moment is given by 11) In terms of Fig.] bl, the axial gas force F,.. acting on lhe orbiting scroll makes the orbiting scroll departure the fixed scroll, increasing the axial clearance Ct.and resulting in apparent decrease of volumetric efficiency.