scoring lines on shaft 1

[mjsamman]

Hi for All,

What is the best practice should be done if we noticed Lot of lines and scoring marks observed on the shaft. as attached picture. Do we have to make more investigation for the reason and collect information or this is a simple finding and no more action required just to make polishing.
Note: we found the journal bearing in good condition without damages.

regards,

 

[desertfox]

Hi

Are the scoring marks superficial or are making an impression on the shaft? The brown/gold areas on the surrounding metal case look like those areas are getting hot during operation, have you measured any temperatures during operation around the bearing?
What lubrication do you use on the bearing/shaft combination or are these dry bearings?

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[rb1957]

what would happen if this shaft failed ? would people be killed, or would a factory lose money (from machine down time) ?

what surface treatment is on the shaft ?

how much imbalance is causing the shaft to wander (in operation) ?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[Tmoose]

Are there pictures of the journal condition at the last overhaul?

Is oil analysis done routinely?
Not just dissolved metals, but some level of particle evaluation too?

Were you able to look at both bearing halves?
Is the bearing lube system pumped circulation with a < 15µm filter?

There is dark buildup on the center section of shaft that does not contact the bearing insert.
That suggests possible shaft currents and excessively long oil change intervals.

 

[mfgenggear]

stop and turn off the machine and hire a failure analysis engineer. the cost of this shaft would justify cost. and possibly save lives.

 

[MintJulep]

You need to make more investigation and collect information.