Oscillations and harmonics issues for components

[Jake Miguel]

Is there a book/report(s) that can shed light on this issue? I am into making custom projects that are powered by engines and one, in particular, I am very interested in making sure I don't get any induced vibrations or oscillations.

Suppose I have my engine affixed to a frame and I wish to have it turn a pulley sheave at some RPM. Now, the secondary sheave that is being turned by the primary sheave is suspended by bearings and rides along on a shaft of its own. With so many variables at play here, is there any good way to actually know if some component with start to shake or whip about? Or, is it more accurate to just fire that puppy off and see what happens and attach accelerometers to the frame and take data points?

 

[FactChecker]

Mathematical analysis of these problems usually require using simulation models. A Mathworks MATLAB and/or Simulink model can be built. MatrixX and SystemBuild is another option. In the complicated problem that you describe I think it would take a lot of work to make an accurate model. If you are not worried that turning on the engine would destroy the device, you could try that carefully. There have been some expensive prototypes that got destroyed on the test stand when the engines were first turned on. Otherwise, you might attaching accelerometers and see how the device behaves when excited by white noise or an impulse. (I'm not sure what test equipment that would require.) The frequency response to such an input would allow you to use some simpler models to study how it would respond to particular RPM.

Even with the best efforts, there can be some risk when the engines are turned on the first time. I recommend a cautious approach on a test stand.

 

[Nidum]

Show me a picture or a well proportioned sketch of the machinery involved .