A Modified Transfer Matrix Method for Modal Analysis of Stepped Rotor Assembly Applied in the Turbomolecular Pump

Table 4

The parameters and assembling modes of the rotor assembly.

	Inner diameter (mm)	Outer diameter (mm)	Length (mm)	Assembling mode
Radial magnetic bearing rotor	26	34	16.5	Clearance fit
Locating ring	26	34	23.5	Clearance fit
Sleeve	31	34	21	Interference fit
Permanent magnet	23	31	21	Clearance fit
Locating ring	22	34	29.5	Clearance fit
Radial magnetic bearing rotor	22	34	12	Clearance fit
Nut	21	34	17.5	Screw joint