Bigger paper machines would use nearly 3000 bearings, most of which would be spherical roller bearing. It would be pertinent to mention here that spherical roller bearings would support substantial axial and radial load combinations of the cylinders and rolls used. They would tolerate misalignments between the housing and the shaft.
Decently lubricated bearings would show little signs of wear and tear or corrosion. They would have lives as long as new bearings. Rest assured that a well-greased multistage labyrinth would provide adequate protection when the housing meets moisture. The wet section bearings are lubricated with grease and the other section bearings would be lubricated with oil.