Automotive Supercharger Design And Pilot Study

The profile of Roots rotor was simplified according to the insufficiency of conventional involute profile on the basis of the practical application of Roots supercharger. Because the area efficiency is not easy to caculate by equations of the simplified profile, the method of modeling under software circumstance is put forward to figure it out. The simplifying effect of rotor profile was proved by comparing of the conventional and the simplified rotor profile. An improving method of the profile of involute Roots rotor is put forward.Parameters of improved rotor such as area coefficient and contact ratio are analyzed. Comparative analysis in discharge pressure and airflow pulsation of the two kinds of rotors under different pressure ratios are made with a kind of rotor in supercharger as example. It is concluded that improved rotor has advantages in specific circumstances, which provides a theoretical basis of the application of this kind of profile.Through the comparison of air displacement between the three-lobe roots supercharger an the two-lobe in the same size and working situation, correct the wrong view of some people that the displacement of the three-lobe Roots supercharger is samller than the two-lobe,and analyse the new technology used in the two types Roots supercharger which is to reduce the noise and vibration effect to find out the advantages of the three-lobe Roots supercharger from the sides of air displacement,noise and vibration.A 3D FEM of supercharger spindle system was built in Ansys, and calculated the first four sets natural frequency and vibration mode by the method of Subspace, then displacements and frequency curves on normal working condition are obtained, at last the influence of drive spindle natural frequency from bearing rigidity is ansysed. This paper makes theory for designing to reduce noise and control vibration of supercharger.According to the structure and principles of the Roots supercharger and based on fluid dynamics theory, the radial leakage, axial leakage and breather hole leakage, the leakage model of Roots supercharger was established.Though the comparison of calculation example and experimental data, the feasibility of this mathematical model was proved. The experiment data is analyzed and this research provides theoretical basis for optimal designing the Roots supercharger.Last, the supercharger is fitted in geely car.Through performance testing, the practicality of the supercharger is checked...