Belt Conveyour pully drum idler Pully Drum In the belt conveyor system, materials are transferred through the movement of the rubber belt on the pulley drum rollers. This system is used to transport raw materials over long distances. Table : Pully Drum up Idler Idler set is used to bear the side loads and prevent the belt from rising and deflecting. Table : Idler Roller These rollers are called rollers according to DIN 15207 standard and include forward, return and guide rollers. up