Performance Calculation Of Dry Scroll Vacuum Pump And Finite Element Analysis Of Key Components

Dry scroll vacuum pump(DSVP)can effectively obtain a clean vacuum environment,and is widely used in semiconductor,medical equipment,biopharmaceutical and other fields.During the working process,the gas pressure in the working chamber changes constantly,the gas temperature changes due to the compression of the gas.The stress and deformation of the scroll plate will be produced under the pressure and temperature load,which indirectly affects the fit clearance.Therefore,it is of great significance to study the working performance and reliability of the DSVP.In this paper,the two-stage series dry scroll vacuum pump was taken as the research object,the geometric theory of the scroll profile was studied.Combined with the gas flow characteristics of the DSVP,the performance parameters of the DSVP were obtained;the finite element analysis of the fixed scroll plate was carried out with the help of ANSYS software.In the specific research process,according to the meshing principle of circular involute scroll profile,and the instantaneous volume of each working cavity was calculated.The continuous change of working cavity volume in the compression process is obtained.Assuming that the DSVP was an adiabatic model,the variation of gas pressure in each working chamber was obtained.Different leakage models were used for different gas flow states.The results show that the radial leakage is greater than the axial leakage.The temperature distribution of each working cavity was obtained by numerical simulation,and the influence of leakage on the temperature change of working cavity was compared and analyzed.The results show that the temperature of working cavity is high when considering leakage.According to the geometric characteristics and gas flow characteristics of the DSVP,the main performance parameters such as pumping speed and limit pressure were obtained.The results show that the pumping efficiency is high when the suction pressure is above 1000 Pa.The fixed scroll was selected as the finite element analysis object,and the gas pressure load and temperature load was applied as the boundary conditions.The results show that the gas pressure load has little effect on the stress and deformation of the scroll wrap,the stress value on the scroll wrap is distributed in layers along the direction of the wrap height.The stress value of the wrap root layer is greater than that of the wrap top layer,and the deformation of the wrap top is greater than that of the wrap root.