Today we present a specific case that demonstrates the importance of correct positioning of bearings for correct performance, for example in the industrial fan sector.
When installing bearings on a horizontal shaft, cantilever fan (example A), the fixed bearing is typically installed closer to the shaft drive system, with the expansion bearing positioned closer to the fan housing. 
If the fan is located between two bearings on a horizontal axis, the fixed bearing is typically positioned between the fan housing and the fan drive system.
The expansion board is located on the opposite side of the fan casing, furthest from the drive system (Example B). When placing bearings in a fan or fan, it is important to remember the location of the fixed and expansion units installed by the fan OEM.
When installing fixed and expansion bearings in a vertical shaft fan, it is important to note the type of shaft drive system used. For vertical shaft fans using a belt drive system, the fixed bearing must be positioned closer to the fan housing and the expansion unit must be positioned closer to the drive end of the shaft (Example C).
For vertical shaft applications with a direct or coupled drive system, the fixed bearing will be positioned closer to the drive end of the shaft and the expansion bearing will be positioned closer to the fan housing (Example D).
When bearings are replaced in any type of fan or blower, it is important to pay close attention to the exact positioning of the fixed and expandable bearings before removal.
While the above recommendations work for 99% of all fans and blowers, in rare cases the units may be installed in locations opposite to those indicated above. This is typically done to ensure that both bearings are loaded correctly based on the specific fan or blower design.
