Noise electric motor

we have a big noise in the electrical motor which it drives the lube oil pump.
45 KW, 400 V - 50Hz
The hydraulic motor pump
Running speed Motor: 1480 CPM
Bearing roller type: DE & NDE: 6314 /C3
unfortunately we are facing a problem in our software, in fact we use the screenshot from analyser Oneprod MVP2-2C to analyse the noise come from the motor.
BPFO = 3.08
BPFI = 4.92
FTF = 0.38
2BSF = 2.05
Find attached the spectrums details.
i suspect that BPFO was defect, but it is modulated by running speed. is it a possible ?

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Original Post

223.8/24.75 = 9.0 xSS.

Perhaps you have a 9-vane oil pump with pulsation at 223-Hz and harmonics, and modulation by 1xSS could be expected. You should consider all forcing frequencies from motor and pump before deciding you have a bearing fault. I have also seen similar data when shaft coupling between motor and pump was very worn.

Walt

ai.engineer posted:

this motor drive hydraulic checkball pump.
I tried to identify all forcing frequencies, but I couldn't pick up the original of noise.
Thanks

Just to clarify, when you refer to "noise", are you referring to something acoustic or something that is part of the vibration related signature?

Definitely yes; the pump emerged inside the tank and there is access to take measurements from the pump.
in this case the noise come from Motor wherein I suspect that the forcing frequencies is related to motor bearing due to there are peaks at 3xBPFO, 6xBPFO and 9xBPFO.
as well, there is a peak at 2x BPFI and 5 xBPFI.
I see also running speed (24,75 Hz) sideband at 6xBPFO

Waht do you think? is it a possible to see BPFO modulated by running speed???

Thanks

It is possible for 1xSS to modulate the BPFO, based on bearing load changing from unbalance or misalignment forces.

Just for fun: ask the pump vendor how many pistons are in the pump or do this search:

Search: 6 pistons hydraulic checkball pump

https://www.bing.com/search?q=...40E3B45B5E0CA83AB3F5

You may be correct about a bad motor bearing, but it may be worthwhile to verify the pump pulsation frequency to avoid an incorrect diagnosis!

Walt

 

 

ai.engineer posted:

we have a big noise in the electrical motor which it drives the lube oil pump.
45 KW, 400 V - 50Hz
The hydraulic motor pump
Running speed Motor: 1480 CPM
Bearing roller type: DE & NDE: 6314 /C3
unfortunately we are facing a problem in our software, in fact we use the screenshot from analyser Oneprod MVP2-2C to analyse the noise come from the motor.
BPFO = 3.08
BPFI = 4.92
FTF = 0.38
2BSF = 2.05
Find attached the spectrums details.
i suspect that BPFO was defect, but it is modulated by running speed. is it a possible ?

dear al

if you have a possible check the motor solo run ,and if you have strainer at suction line when have you checked it last time?  

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