The Difference Between " Cylindrical Bore" and "Tapered Bore"

I haven't ever encountered it before, but it is conceivable that a bearing could be mede to fit onto a tapered shaft (cone rather than cylinder). This might serve some self-centering or other alignment purpose.

Typically the cylindrical bore is used on a shaft that is machined to a specific length with a stepped end to lock the bearing onto, whereas a taper bore can be mounted for example "anywhere" along a cylindrical shaft. The reason being that a tapered sleeve is placed on the shaft first and the bearing is tightened onto the taper. The typical use for this bearing is high vibrationary loads as in hammer mills etc, where a cylindrical bearing may become loosened and move. If correctly mounted, it is almost impossibble for a tapered bore bearing to move (ever)

Often also used on large heavy pices of equipment. Theres another GA for u.