I'm taking the readings on the motor housing directly in front of the bearing. That was the only flat spot I could find.

Yes I know. 1.0 ips is not good. When balancing I shoot for .09

Let me ask one more question if I may. Do you recommend replacing the shim packs on a timeline basis, even though it looks good? This coupling has been in service for about 2 years now...

Much (good) talk about alignment procedure but did you check for some other obvious conerns such as loose bolting and full (i.e. proper sized) shims? Possible resonance? Odd that the motor only is feeling the effect.
I ran into problem at our Site where large cooling pump was returned to service and had hi axial....all alignment checks SAT.
Root cause was finally determined to be loosened base plate in the base.
I assume its all at running speed?

I just went out with a strobe and saw this...I didn't have this during the alignment. This is on the blower side not the motor.

All our blowers are mounted according to the specs of the blower manufacturers.

They are bolted to a frame, then mounted loosely on hard rubber pads. All was fine in July, until I saw the ODE bearing starting to fail. Everything in the green, so I'd assume there is still no structural looseness after I put it back together.

quote:

Originally posted by ivibr8:
Much (good) talk about alignment procedure but did you check for some other obvious conerns such as loose bolting and full (i.e. proper sized) shims? Possible resonance? Odd that the motor only is feeling the effect.
I ran into problem at our Site where large cooling pump was returned to service and had hi axial....all alignment checks SAT.
Root cause was finally determined to be loosened base plate in the base.
I assume its all at running speed?

Your photo: looks like it's a combination of Thomas and 'home-made' items with machine bolts added. I may be wrong but it looks poor?!

The wavy shim pack is bad and needs replacing; what would happen if it flew apart without the guard in place? The one's I mentioned in Atlanta - they had thrown wedges out and were imbedded in the walls and ceiling.

If you are going 'in' and 'out' of the tolerance box my suggestion would be to improve your design to keep it within reasonable numbers or go to a gear type coupling. Got the budget, get the Acculign alignment system.

It wouldn't surprise me Sam, haha...We do have some rigged up stuff around here. Thats why I'm digging to see whats right and wrong. Many of these problems I'm seeing were not covered in the Technical Associates Level one class and exam...

Thats why I appreciate all your guys years of experience. Wish I had started this earlier in life, but our company began vibration monitoring in late 2000. I've been full time since 2003...I retire in 7 years, but I would still like to progress higher. Gets frustrating at times. Still got some sanity left at 55...hehe

Thanks

Rod,

You might want to count the shims and see if you are "playing with a full deck" for the rated torque and speed. The extended bolt length looks suspicious.

Walt

Walt,

If there is a standard for this based on my application, where could I find this info?

This is what we've used all these years. The coupling size is a Thomas 350

Here is some follow up from the blower issue, from this morning.

We went out and did a hot alignment. The tolerances for a 3600 rpm machine are .5 angular and 2.0 offset

It was .1 & 1.1 and both vertical and horizonal positions were below .002 . Can't beat that.

I did however find that the keyway in the motor hub was protruding too far out, and that probably it was hitting the coupling. Causing my shim pack to have separated shims, or gaps in them.

We ran the motor uncoupled and the readings are worse now, than when it was coupled to the blower.

I'm inclined to believe there is still an internal motor problem. Even the acceleration readings on the bearings are in yellow alarm. I'm pretty much out of ideas, but I do know I will recommend not using this blower. Perhaps we should get the motor repair shop people out here to look at it.

Any ideas at this point? I'm out...

Motor WOrse!!!!

Well it does sound like something is wrong with the motor, huh?

Did you do a monitor as the power was shut off to see if the vibration was electrically induced?

I just happened to remember when I was at a plant doing a training in analysis in February, they had 2 motors that had a high vibration in the axial direction. We never ran them uncoupled but did do a bump test and both showed to be resonant at running speed in the axial direction. We stiffened the base on one to fix it but the other one they never did do anything while I was there due to being in a scheduled shutdown on the day we bumped the second one and it was not on the schedule right then. I am sure they done some corrective repair later.

Of course from what I am getting from your posts, this motor ran fine prior to sending it out for repairs, or did I miss something?

This message has been edited. Last edited by: Ralph Stewart,

Walt gave some good advise. Check the bolts; don't look proper.

Your alignment specs - appear to be very bad! The tolerances for 3600 RPM should be on a Thomas 1 mil (0.001") and 30 seconds - this is 1/120th of a degree. If your 0.5 angular is 1/2 degree then that equates to 30 minutes and is extremely out of tolerance. That would wave the shim pack no doubt. I assume your 0.1 is 0.1 degrees or 6 minutes angular = very bad or way out of tolerance.

I would go back on the spool piece and disc pack and assembly bolts. Re-check and correct, plus, correct alignment.

For some reason I posted too early. I'll finish...

Anyway, this also explains why I got extremely high axial readings on the motor...Cocked bearings would do this. Glad I took those phase readings yesterday, and documented them...My Technical Associates wall chart fits my spectrum to a "T"...

I think we are having the motor shop come out and look at it too...

Let me explain that again Sam..

On our alignment equipment the Vibralign V180 system, gives us the overall tolerances at 900,1200, 1800 & 3600 rpm...For 3600 it is .5 for the angularity, and 2.0 for the offset...This measurement is not in mils, this is the overall alignment condition.

When I switched to the actual mil readings they were between .0007-.0015, almost perfect. I can't do any better than that.

We've already removed the old coupling. No longer a factor. The axial readings being 1.1 ips would also indicate cocked bearings as well.

I may go out and run the motor again uncoupled and loosen up one foot at a time to see if the vibration goes away...

quote:

Originally posted by Sam Pickens:
Walt gave some good advise. Check the bolts; don't look proper.

Your alignment specs - appear to be very bad! The tolerances for 3600 RPM should be on a Thomas 1 mil (0.001") and 30 seconds - this is 1/120th of a degree. If your 0.5 angular is 1/2 degree then that equates to 30 minutes and is extremely out of tolerance. That would wave the shim pack no doubt. I assume your 0.1 is 0.1 degrees or 6 minutes angular = very bad or way out of tolerance.

I would go back on the spool piece and disc pack and assembly bolts. Re-check and correct, plus, correct alignment.

Is 0.7 mils good enough? What is the distance covered?

If you span 10 inches and use 15 seconds as tolerance the tan is 0.000075 - so, 0.00075 is the tolerance. But as you can see 0.5 and/or 0.1 degrees isn't tolerance. Read their manual and check what they are doing. Appearance is, something don't add up. BTW; 1.5 mils or 80% of the diameterical clearance of the bearing will suffice for a machine of this type if classing as a rigid coupling.

Hello Sam,

All I know is, according to the V-180 user manual, when in the act of moving a macine and zeroing in on the target, mils = .000 or overall 0.0 If you look at the vibralign web site link I put here, on the controller you hit the up arrow to scroll back and forth from actual mills vs Overall tolerances. This is how the unit works, and once you get below the .5 and 2.0 overall value, in the case os this 3600 rpm machine, your good to go.

I can't explain it any better than that. We've used this V-180 for 6 years now, and it has been performing remarkably well.

Here is the link:
http://www.reliabilitydirect.com/alignmentproducts/ACC-V180.htm

I don't know about all this degrees and seconds in relation to good number...This unit does not require that you know that. You just get it under the acceptable value, and thats it...

quote:

Originally posted by Sam Pickens:
Is 0.7 mils good enough? What is the distance covered?

If you span 10 inches and use 15 seconds as tolerance the tan is 0.000075 - so, 0.00075 is the tolerance. But as you can see 0.5 and/or 0.1 degrees isn't tolerance. Read their manual and check what they are doing. Appearance is, something don't add up. BTW; 1.5 mils or 80% of the diameterical clearance of the bearing will suffice for a machine of this type if classing as a rigid coupling.

Sorry,

I meant when you hit the (+) sign on the controller, not the up arrow...

quote:

Originally posted by Rockin' Rod:
Hello Sam,

If you look at the vibralign web site link I put here, on the controller you hit the up arrow to scroll back and forth from actual mills vs Overall tolerances. Here is the link:
http://www.reliabilitydirect.com/alignmentproducts/ACC-V180.htm

I don't know about all this degrees and seconds in relation to good number...This unit does not require that you know that. You just get it under the acceptable value, and thats it...

quote:

Originally posted by Sam Pickens:
Is 0.7 mils good enough? What is the distance covered?

If you span 10 inches and use 15 seconds as tolerance the tan is 0.000075 - so, 0.00075 is the tolerance. But as you can see 0.5 and/or 0.1 degrees isn't tolerance. Read their manual and check what they are doing. Appearance is, something don't add up. BTW; 1.5 mils or 80% of the diameterical clearance of the bearing will suffice for a machine of this type if classing as a rigid coupling.

Have you checked for a soft foot condition on the motor? Try loosening one foot at a time, while running, and see if vib. changes while uncoupled. Even axially is possible, if there is some deformation of stator.

Stan,

I did all that yesterday morning, if you look at my earlier messages.

I also checked axial on the motor while doing phase readings, amplitudes out the top...Motor uncoupled and running. No change while loosening feet. I was even watching my microlog while doing it. Soft foot to my knowledge causes a 1X dominant peak vibration, not 2X

I think the V-180 is Fixture Laser. Re-painted for SKF and Vibralign or I could be wrong.