Got a question on Fan Bearings
Got a question on Fan Bearings
(OP)
We have had numerous bearing failures because we have had the fixed type bearing closes to the fan housing and the "floating" bearing on the outboard. Our seasoned maintenanc guys say the fixed should be on the outboard and floater inboard. Engineering says the opposite. Our drawings aren't detailed enough to determine which goes where....so what do you all say? I'm trying to find documentation but can't. OEM hasn't gotten back to me yet.
ShelleyGA
ShelleyGA





RE: Got a question on Fan Bearings
RE: Got a question on Fan Bearings
Russell Giuliano
RE: Got a question on Fan Bearings
Try the opposite and see what happens.
I find it hard to believe that you do
not have a manual for replacement parts
that would define which bearing is which.
I would expect that the radial bearing be
near the blade and the thrust bearing at
the other end. Too bad the OEM did not
make the bearings different enough so that
they could not be interchanged.
RE: Got a question on Fan Bearings
RE: Got a question on Fan Bearings
of the motor or service manual.
So sad that they are not more helpful.
RE: Got a question on Fan Bearings
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Got a question on Fan Bearings
RE: Got a question on Fan Bearings
http://www.skf.com/files/003920.pdf
Its difficult to compete with CARB in fans, but easy in other applications. They tend to complicate most apps, its easier to stick to sphericals...
RE: Got a question on Fan Bearings
RE: Got a question on Fan Bearings
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Got a question on Fan Bearings
If a warm shaft expands axially against 2 identical bearings they both die.
The "correct" location for the fixed bearings will abso,utely vary with application. What is important is Axial shaft growth should never result in bearings fighting each other on one shaft OR between the driving and driven machines
The axially fixed bearing should go at the end that can least afford axial growth, and the floating bearing must be set so that it will not be axially restrained while in operation.
If the coupling has limited axial expansion capabilities (unfortunate coupling choice) then the fixed bearing should go near the coupling, being sure the coupling gap starts centered or biased to prevent the driver/driven shaft ends ever bump or the coupling axial compliance is exceeded.
If there is close fitting shrouding and the fan is in a hot process then keeping the fan wheel axially positioned at operating temperatures may be most important, and the axially fixed bearing belongs near the fan wheel, with the wheel centered, and still with the couping gap set to accomadate all intended axial shaft expansion.
RE: Got a question on Fan Bearings
rmw