A series of high capacity turbomolecular pumps with pumping speed up to 40 m3 s−1

Experimental and performance analyses of a turbomolecular pump rotor system

“…Damping and stiffness matrices are non-symmetrical and dependent on speed because of the effects of gyroscopic moments, anisotropic bearings, and material damping. Therefore, Equation (12) should be solved in a different manner. The second order homogeneous Equation (12) may be typically reduced into 2n times the first order differential equations.…”

“…Calculating the critical speed of the rotor system To calculate the critical speed of the system, the following homogeneous equation, that is, Equation (12), should be solved:…”