Definition of Friction Lifting Core Roller Set: Friction rollers  are mainly used as self-aligning idler sets. A commonly used self-aligning idler set has a bracket that supports the  idler set, which is mounted on the frame through a rotatable pivot point. When the conveyor belt deviates, the idlers installed on the bracket can be deflected relative to the conveyor centerline, moving the conveyor belt back to the conveyor's centerline.