Gentelment, I got problem with installation of water chiller pump, the vibration dominate at pump drive end in 3 direction (Axial, Horizontal, Vertical). Machine configuration : Motor + Coupling + Centrifugal Pump installed on rigid foundation (grouting)....I will post the picture soon.

SUSPECT
- Unblance..... not sure with this because amplitude of 1X in three direction almosts equal.
- Shaft Aligment....I controled, not exceeded 0.05 mm.....do it need more precise
- Shaft Bend....how to check without phase reading.
- Looseness....already recheck for bolt tight.
- Pipe Strain....

Please take your consideration to spectrum and give me your advice, I been trying to solve this problem for longtime.....until now the pump have not permission to run due to vibration can not acceptable.

Thankyou and bestregards.

CWP.doc (106 Kb, 43 downloads)

Phoo,
When you asked about bent shaft, have you put a dial indicator on it. I recently had a job that looked like misalignment including 180 degree phase shift across coupling. When I questioned the alignment, it was rechecked only to be found ok. I put my dial indicator on the driven shaft and found enough run out that the shaft had to be replaced. Not sure if this is your porblem but it would be an easy check.

Good Luck,
Ronnie

Alignment: soft foot - eliminate. Parallel within 2 mils or 0.05mm. Angular within 45 seconds. Pipe strain; max of 2 mils. Bent shaft; chect as suggest w/dial indicators on shafts and hubs.

With pipe strain, check flanges for parallel and be able to wiggle a bolt in every hole freely.

Thank all, I am now action as you had advised....and the result as attached.

The coulping of pump drive end may be deformed and eccentric.......I'll post spectrum after coupling had corrected.

Regards.

Thanks for your advice, if the shaft bent during running (speed 1480 rpm)...how can we know...have you ever putted a dial indicator on running shaft.

quote:

Thanks for your advice, if the shaft bent during running (speed 1480 rpm)...how can we know...have you ever putted a dial indicator on running shaft.

Are you saying the shaft is possibly running under a "bent" condition and not bent when at rest?

What type of coupling has it got? Grid, gear, "paraflex", shim pack, dropout grid?

quote:

until now the pump have not permission to run due to vibration can not acceptable.

If this is the case and you can't run the pump due to excessive vibrtation, why would it be necessary to check runout with it running. When I suggested checking with a dial indicator I assumed the unit was not running. Checking with a dial indicator with the unit running would not be possible.

Thanks,
Ronnie

Hi Ronnie/Ralph

I already checked for runout (at rest condition), please see attachment.

Now I plan to replace new coupling, the result will be posted soon.

Chiller_Pump2.xls (22 Kb, 28 downloads)

So, nothing in tolerance and a mis-bored coupling! Can't get much worse.

Phoo,

Was the coupling hub hammered on?