The shaft collar is a simple, yet important, machine component found in many power transmission applications, most notably motors and gearboxes. The collars are used as mechanical stops, locating components, and bearing faces. The simple design lends itself to easy installation.
The locking collar has a counterbored recess made purposely eccentric to the collar bore. When assembled on the shaft, this eccentric recess engages, or mates, with an eccentric cam end of a bearing’s inner ring. … This assembly grips the shaft tightly with a positive binding action that increases with use.