Large machine resonance

[testtech]

A demonstrated resonant condition exists in a gearbox. Vibration of 1"/sec is measured on the structure at 330 Hz. The gearbox is driven by a 1000 HP DC motor and runs a rolling mill. The gearbox is about 6' by 6' by 4'. It sits on a concrete foundation that reportedly extends 8 feet underground. An operation deflection shape animation indicates that the foundation is rocking back and forth at the resonant frequency. The resonant frequency is gearmesh frequency. Here is the question: is it reasonable to have a resonance on such as masssive structure at 330 Hz. or should I be seeking another source?

 

[steve383]

Have you done anything with the gear box yet? I am trying to have my customer rebuild his gearbox due to bearing faults. They will be inspecting it soon. I want to do some resonace testing of the shafts and box at that time. I will let you know if I find any thing interesting.

 

[corushtd]

What product do you use the mill for? back here we have some mills for steelstrip production and frequenties like that do happen when several mills come in resonance with eachother.

 

[testtech]

steve383:

Nothing yet.

corushtd:

The mill is used to take steel delivered on a roll to reduced thickness. IT is then processed to a final product.