would appreciate any advice you guys could give me

Issue - 1 Dryer Bearing housing vibration , 54 total dryer cans.

Tending Side housing has high peak and harmonics of 5x the idler or intermediate gear running speed from the drive side gears.

dryer gears = 68 tooth
intermediate and idler gears = 47 tooth
68/47 = 1.4468 x

I know speed is correct or at least I feel confident it is, but always can be proven wrong.

At high speeds, the tending side housing shakes at or above 10 mils at this frequency.
It has the appearance of a bearing defect, by harmonics and looks, but the bearing has been checked, its ok.

The dryer gear and a idler gear has also been changed, idler pin was worn, gears were damaged, etc.

But.. after new gears, new pins, etc we still have this high vibration on this one dryer that appears to occur at 5x the idler gear running speed.

The ladder bearings under the housing has been changed also.

some suggest changing this tending side housing. but to me it looks like the source still points back to a problem in the gears that is causing this.

Any thoughts ?

Thanks
Mike

DRYERPROBLEM.ppt (36 Kb, 59 downloads) Dryer Bearing Housing Problem

Mike,

What is the phase and amplitude differences between the north side and the south side of the housing and the difference between the top and the bottom of the housing at the frequency it is moving? And then the difference between the top to the side to the bottom to the other side?

in phase

top bottom and sides move same direction
in phase.. but amplitude is higher at the top
than any other location.

thoughts? cocked bearing ?
It isnt in the housing.. have taken the cap off and measured distances from race to outside of housing.. same distance within reason.

This is the floating end, as you know.

I wanted to pull the bearing off the journal, just to get a look at what the journal looked like.. was a no go.. time limit.

not much of a problem around 800 fpm or slower.
It moves and shakes but will be around 3 mils or lower. get up to 975 and were seeing 11 mils or more on the side and up near 20mils at the top of the housing
but were getting over 900fpm alot.. even up to 980.. waiting to push the 1000 mark but so far havent.

this is the ONLY dryer can bearing housing doing this.

I still think its being excited by the gears and or rotation of the idler or intermediate gears since it is always at a 5x or 6x idler gear rps that exhibits the highest vibration.

I am going to bump the housing.. just to see if there is a resonance in the housing around this frequency that gets excited at the higher speeds..

If thats the case.. maybe a new housing might help.. if the housing in now isnt seating on the ladder bearings good and lying flat but rather bowed it could be a factor ?

Its been an ongoing problem.. only giving real high amplitudes when were above 900fpm.
New housing is in.. they may change it in future.