As there were leak on contact place between shaft and rotor body in built up hollow rotor, dropping discharg gas speed of pump and efficiency applied of oil sealed sliding vane rotary vacuum pump.

First of all, the mathematical model of the flexibly supported rotor with wriable mass is built up.

In order to enhance the credibility of the model, based on the experiment of the rotor response characteristics to rapid control input, a noolinear aerodynamic model of the rotor was built up.