is this a Common factor problem or bad gear mesh

[newvibrationanalyst]

2990 rpm motor driving two stages gearbox WHICH driving apump (gear box and pump data)
input shaft 2990 rpm 49.83 HZ
idler shaft 6795 rpm 113.26 HZ
high speed shaft 11461 rpm 191.02 HZ
blade pass frequncy (8 blades ) 1528 HZ

FIRST STAGE
input gear has 125 teeth and meshes with a 55 tooth gear so the upper GM (gear mesh =6229.17 hz )
THE SECONDE STAGE
gear has 113 teeth meshes with a 72 tooth gear
lower GM (gear mesh = 12798.11 HZ)
the spectrum data of the gear box show low amplitude for the upper and lower gear mesh and also show frequencies of 1/5, 2/5, 3/5, 4/5 of the upper GMF 6229.17 hz which has acommon factor =5 and which did not previously exist ( 125=5*5*5 55=5*11 lcf=5)

the spectrum data of the pump show blade pass frequency which was increased and crest factor reach 4.67
the gear box is very noisy althogh the gears are helical type
is this aclearance problem or wear on gear teeth problem
please help
attachment (spectrum and time wave form )
PLEASE STATE ur comments on the time wave form
1-low quality gear mesh
2-common factor problem
3-gear wear
4- any thing else

 

[IRstuff]

Is this for school

TTFN
faq731-376

 

[electricpete]

Quite obviously not for school.

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(2B)+(2B)' ?

 

[newvibrationanalyst]

no iam so sorry but iam really beginner vibration engineer and i faced the problem mentioned above
thank u for ur reply
and i am so sorry for this post

 

[newvibrationanalyst]

not for school it is for engineers only like eng strong and not for technician

 

[electricpete]

If you don't get a response here, you might try maintenanceforums.com

There are a lot of rotating equipment condition monitoring professionals there

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(2B)+(2B)' ?