Full definition
A tail pulley is a crucial component in conveyor systems, located at the loading or feed end, opposite the drive drum. Its primary function is to redirect the conveyor belt as it returns after discharging materials. Typically non-motorized and functioning as an idler pulley, the tail pulley is essential for maintaining proper belt tension and alignment, which are vital for the efficient operation of the conveyor. The typical diameter of a tail pulley ranges from 50% to 75% of the diameter of the drive drum, adhering to the minimum bending radius specifications of the belt being used. This construction allows for effective redirection of the belt and minimizes wear caused by excessive bending. Tail pulleys are generally constructed from welded steel and feature stub shafts and bearing housings to support the pulley and facilitate smooth rotation.
In addition to their structural role, tail pulleys often incorporate a screw take-up mechanism that allows for fine adjustments in belt tension. This mechanism can accommodate travel distances of approximately 1.5% to 3% of the total belt length, ensuring that the belt remains taut and properly aligned. In longer conveyor systems, a gravity take-up may replace the screw adjustment, relying on the weight of the take-up system to maintain belt tension.
Tail pulleys can also feature self-cleaning designs, such as wing or spiral configurations, which help shed material buildup that could lead to mistracking of the belt. This is particularly important in environments where material accumulation can be problematic. While rubber lagging on the tail pulley is optional, it is highly recommended in wet or slippery environments to enhance traction on the return belt. Proper alignment of the tail pulley is critical, as it serves as the primary adjustment point for correcting any belt wander, thereby ensuring the longevity and reliability of the conveyor system, as outlined by CEMA (Conveyor Equipment Manufacturers Association) standards.