high vibration acceleration levels on the DE side of a motor (two bearings)

[EL AABD Jamal]

Hello,

We replaced the bearings of a motor. After commissioning the vibration acceleration levels on the DE side (consisting of two bearings) are high. However, they decrease significantly after the lubrication operations.

The vibration velocities in mm/s remain stable.

What conclusions can be drawn from this vibration analysis?

 

[Daren Samy]

Please check the fits of bearings and bearing housings. I have worked for bearings related maintenance for previous 6 years. Though sufficient data can help to deduce any result but greater probability lies with wrongly maintained/installed bearing housings/bearings.

Daren!

 

[electricpete]

The acceleration is quite broadband (no single peak is very high).

I do see the software highlighted peaks with integers 1, 2, 3 etc which presumably indicate these are harmonics of something. What are they harmonics of... running speed or a bearing defect frequency? (if bearing defect frequency, please provide more details)

Did you have documented satisfactory operation without this pattern before bearing replacement?

Are the above results in the uncoupled state or coupled state? Does the pattern change between uncoupled and couplied state?

What does the motor drive? And through what type of power transmission (belt drive or coupling etc).

Can you tell us what are the two bearings part numbers on the DE. Also any additional info about how they are mounted and in particular anything that affects axial loading like shoulders, locknuts or wavey washers (diagram would be great if it's available).

What is the horsepower and speed of the motor?

Fwiw, most of my questions are geared toward evaluating the possibility of whether this might be skidding due to insufficient loading of one or both of the DE bearings. That's my best SWAG at the moment but your answers may weaken or strengthen that opinion. If it was documented not happening before then that's probably not the case. I take it previous poster suspsects bearing outer ring is spinning in the housing or inner ring spinning on shaft... could be.