They serve for fixing a roller bearing with a tapered bore onto a shaft, consist of a tapered metal sleeve, a tab washer and a locknut made of steel. Upon fixing a bearing through an adapter sleeve the inner ring of the bearing adopts the function of an annular spring and presses the slotted adapter sleeve onto the shaft. The internal clearance of a roller bearing can also be adjusted by the adapter sleeve at the same time. A hook wrenches is used for tensioning.
