Are all spectrums shown taken on the motor inboard? None on the outboard end?

Your drawing calls the "motor" a "turbine". Is it actually an electrical motor?

The drawing also does not show a coupling between the "motor" and the gearbox. Is there a grid coupling there or is the "motor" bolted directly to the gearbox.

What type bearings are in the "motor"? Sleeve or anti friction?

What kind of amplitudes are on the gearbox?

Thanks,

Ralph

Ralph Stewart posted:

Are all spectrums shown taken on the motor inboard? None on the outboard end?

Your drawing calls the "motor" a "turbine". Is it actually an electrical motor?

The drawing also does not show a coupling between the "motor" and the gearbox. Is there a grid coupling there or is the "motor" bolted directly to the gearbox.

What type bearings are in the "motor"? Sleeve or anti friction?

What kind of amplitudes are on the gearbox?

Thanks,

Ralph

we have no route defined this is an emergency/dummy equipment.Consider motor as a turbine. Don't go for name.

All spectrums are of Pillow block of fan side because no high readings was observed at P.block(turbine side).

There is a grid coupling between gear box and plummer block.

Vibration readings on turbine and gear box cannot be taken because of site constraint but there is no high vibration.

Plummer block have Roller bearing (22218)

Amplitude on gear box outboard (goes to coupling) is from 1.3-2.4mm/sec-which is satisfcatory as per trend.  

OK.

That does make a difference.

Fan Side Bearing? Might be unbalance rather than "looseness". Just my first guess.

Is there any looseness or movement of the pedestal around the Fan Outboard (Fan side) bearing?

Overhung fans are noted, IMO, to have a high axial amplitude as well as radial when out of balance. But I would check everything to see if there is something  loose or broken on the pedestal first, before calling unbalance.

I assume it is an overhung as shown in the drawing, huh?Thanks and Have a Great Day,

Ralph

hello guys:

WE have found that the bearing was loose in plummer block , inside surface of p.Block the marks (scratches) was observed. also sleeve was shear..The vertical and axial vibration levels goes down (attached) but we have another peak after complete change of p.block, bearing and sleeve.

What you say about the attached spectrum for HORIZONTAL READINGS high showing 2X and 2x harmonics: 2x,, 4x, 6x--------cont. (if we see it in acceleration)

Attachments

mohiuddin posted:

hello guys:

WE have found that the bearing was loose in plummer block , inside surface of p.Block the marks (scratches) was observed. also sleeve was shear..The vertical and axial vibration levels goes down (attached) but we have another peak after complete change of p.block, bearing and sleeve.

What you say about the attached spectrum for HORIZONTAL READINGS high showing 2X and 2x harmonics: 2x,, 4x, 6x--------cont. (if we see it in acceleration)

 

Good Job.

Can you explain what you mean when you say, "sleeve" and "also sleeve was shear"?

I would guess that the bearing is on a tapered sleeve. But I do not understand what is meant by "shear".

Was the new bearing housing confirmed to be mounted in alignment with the shaft and not skewed or cocked  and not parallel to the center line of the shaft, which would make the rollers run "in" on one side and "out" on the opposite side in the outer race ring? 

Self aligning bearing have a "limit" as to how far out of alignment they can be.

Just a suggestion.

Thanks and Have a Great Day,

Ralph

 

Ralph Stewart posted:
mohiuddin posted:

hello guys:

WE have found that the bearing was loose in plummer block , inside surface of p.Block the marks (scratches) was observed. also sleeve was shear..The vertical and axial vibration levels goes down (attached) but we have another peak after complete change of p.block, bearing and sleeve.

What you say about the attached spectrum for HORIZONTAL READINGS high showing 2X and 2x harmonics: 2x,, 4x, 6x--------cont. (if we see it in acceleration)

 

Good Job.

Can you explain what you mean when you say, "sleeve" and "also sleeve was shear"?

I would guess that the bearing is on a tapered sleeve. But I do not understand what is meant by "shear".

Was the new bearing housing confirmed to be mounted in alignment with the shaft and not skewed or cocked  and not parallel to the center line of the shaft, which would make the rollers run "in" on one side and "out" on the opposite side in the outer race ring? 

Self aligning bearing have a "limit" as to how far out of alignment they can be.

Just a suggestion.

Thanks and Have a Great Day,

Ralph

 

Hello Ralph:

The bearing was not directly mounted on the shaft, rather it is mounted on the sleeve (a simple cylinder piece onto the shaft).

Sleeve shear means,I refer that the sleeve was tear longitudinaly.

I guess the overall levels are not that high. Also , if values are not trending upwards then any further corrective action  may not be required just collect few more data sets at shorter time intervals.

in my opinion,spectrum indicates misalignment. As a first step, check the shaft concentricity with sleeve bearing and ideally shaft run out as well. 

I would suggest to take motor readings too and if the same spectrum if observed at motor DE then inspect coupling and check alignment.  

 

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