This study focuses on the experimental and performance analyses of a vertical turbomolecular vacuum pump (TMVP) rotor system. This approach can adopt various methods, such as numerical parametric analyses and experimental measurements. The analysis process can verify the finite element models of the rotor system under different boundary conditions by using pump system assembly testing data. Afterward, the dynamics characteristics of the rotor system must be calculated and compared with the experimental results to verify the models. Finally, the relationship between rotor critical speed and bearing stiffness can be established to study the design of the TMVP rotor system. The experimental analysis can adopt static modal and dynamic testing. Static modal testing can provide the natural frequencies of the rotor system. The waterfall diagram of dynamic testing can measure the operating critical speed of the vacuum pump system from 0 rpm to the operating speed and ensure that the operating speed is far from the critical speed or at least within 10% of the safe margin. In summary, results of the experimental testing and numerical parametric analysis can provide the basis for the design tool of the TMVP rotor system to identify and prevent vacuum pump vibrations.
