Wire Vibration

[Husam1]

Dear All,
I believe I have a unique problem. To best describe it, I would request you to first have a good look at the attached sketch:
- This machine runs a steel wire at about 3000 RPM.
- The wire needs to continuously run WITHOUT any vibrations.
- The Two green pulleys are mechanically attached and move in Up/Down Directions.
- The wire between the two green pulleys runs smooth, then all of a sudden starts to vibrate for a few seconds then go back to run smoothly.
- We increased the wire tension; but that did not help!
- changing the drive speed did not help!
- We replaced the pulleys; but that also did not help!
- This vibration occurs even if the green pulleys are stationary; but worsens when these pulleys move!

I'm no mechanical engineer and was wondering if this vibration was due to:
- Wheels imbalance (supplier confirmed all are balanced).
- Improper wire tension.
- The configuration/arrange of the pulleys WILL cause Vibration. i.e. This machine was incorrectly designed!!
What is it!!!

I appreciate your help and advise.

Thanks,

Husam

 

[Husam1]

Dear All,

I wish to thank you all for your comments, suggestions and advise. I've found the culprit! As simple as it may sound; but the problem was looking us at the eyes and we couldn't see it. It was a wheels misalignment problem.

Our technicians were using basic alignment techniques, and a laser pulley alignment tool (used for engine pulleys); but this does not work (or is not applicable) for this machine. We are not using belts; it's a wire. What needs to be aligned is not the pulley faces; but rather the wire grooves. When they realized this, and made correction in a crude way, the vibration dissipated almost completely.

Now, we are sourcing a laser alignment tool to allow us to have precision alignment of all the wheels.

Again, thank you all for your help and support.

Regards

Husam