Amplitude of harmonics higher than fundamental frequency

[Honza]

Dears,

I have an vacuum pump creating the vacuum approximately 10^-8 mbar. The rotor consists blades and it's placed in bearings. One side is ceramic bearing and the other one is maglev type(magnetic). I measure noise and vibrations of the pump. Significant peak of both units is naturally at rotating frequency (1000Hz). The spectrum of both units is shown in attachments. All other pumps measured have significant noise only on 1000Hz, on other frequencies is negligible. Does anyone hav an idea what can cause such behaviour? Thanks

 

[Vailanor]

in advance.It is possible that the noise and vibration you are experiencing is due to resonance from the pump's rotor blades. This could be caused by an imbalance in the blades, or a mismatch between the weight of the blades and the speed of rotation of the rotor. Additionally, the bearing type and material may contribute to the resonance, as well as any other components or materials that have been added to the system. To determine the source of the resonance, you may need to investigate the design of the pump and its components in detail.