Adapter sleeve direction with axial load

[caoimhin1]

Consider a fan shaft supported by two spherical roller bearings on adapter sleeves in split plummer block housings. Motor directly coupled to the shaft. Fixed bearing at motor end, free bearing at fan end. Fan exerts a radial and axial load on the shaft.
Focusing on the adapter sleeve on the fixed bearing which will take the axial load. Does anyone have a preference as to which way around the adapter sleeve should go, i.e. with the lock nut on the fan side of the bearing, or the lock nut on the motor side of the bearing?
My own preference would be for the lock nut to be on the fan side of the bearing. If its on the motor side, then the axial load could push the adapter sleeve further into the bearing causing clearance reduction.
Any thoughts?

 

[Tmoose]

It's a good thought, to optimize the direction of thrust. Unless there is a shoulder on the shaft (toward the coupling, and thus hard to do in the configuration you describe I think the adapter is likely to just slip on the shaft anyhow.

I think consideration of ease of installation and removal for maintenance may define the orientation

 

[ischgl99]

I have never seen anything in any of the bearing manufacturers literature stating a direction of the adpater sleeve due to thrust load. They all state the locknut should be on the outboard side for assembly and disassembly, that would mean the motor side for the way we do maintenance here. The drawings for the fan in our plant however state the locknut should be facing the casing side of the fan, or opposite of what we would need to install the bearings if we used a hydraulic nut.

My feelings on the subject, if the thrust is pushing the bearing further up the taper, or loosening it in the opposite direction, you have more important problems to solve then worrying about which direction the lock nut should be on. If the bearing is properly installed, there should not be any axial movement of the bearing on the adapter sleeve.

 

[geesamand]

With the high inertia of the fan assembly, I suspect there would be very little force tending to act on the locknut on startup and shutdown. I would position the locknut for maximum access.