Ok so In general I hear that if the bearings are not made for axial load,
obviously keep the fan horizontal. But in the case of having to use the fan
vertically, there is no consensus as to whether to go up or down shaft
because the fans can be designed specifically for both, up, down or just for
axial load. The mystery fan does have ball bearings with spring loaded
thrust bearing (cheap, but still a thrust bearing) and the manufacturer does
not see a problem with the orientation. Someone suggested that dust would be
minimal because of cooling ventilation, however these motors are
hermetically sealed and all brush dust stays inside. It does not look nice
when you open an old one, that's for sure. I think I got my question
answered, basically if the bearings can take it, it is OK, but for sure
vertically mounted motors will have reduced life over horizontally mounted.
thanks all who replied.
regards,
Alfonso
