Tail Pulleys

The tail pulley sits at the loading end of the conveyor — the point where material is introduced onto the belt. Its primary functions are to support the returning belt, establish the initial belt wrap, and maintain correct belt tension and tracking at the feed end. Unlike the drive pulley, the tail pulley does not transmit torque; it simply redirects the belt from the return strand to the carry strand while supporting the belt under the load of incoming material.

Minimum tail pulley diameter is governed by the belt carcass type (EP, NN, or Steel Cord) and strength class, following ISO/DIN standards. Using a pulley smaller than the minimum diameter causes excessive bending stress in the belt carcass at each revolution, leading to premature delamination or ply fatigue. The tail pulley is typically smaller than the drive pulley, but must still meet the minimum diameter requirement for the specific belt selected.

Wing pulleys are specified when material carryback is a concern — particularly with wet, sticky, or fine-grained materials that adhere to the belt backing. The open wing design allows material trapped between the belt and pulley to fall through the gaps between the wings rather than building up on the shell surface. Without this, material buildup causes uneven belt loading, accelerated belt wear, and tracking problems. Wing pulleys do impose higher dynamic belt loading and should be sized accordingly.

Most tail pulley assemblies incorporate slotted take-up frames or screw take-up mechanisms that allow lateral adjustment of the pulley position. Tilting the tail pulley slightly — raising one end — causes the belt to migrate toward the lower end, which can be used to correct chronic off-centre tracking. However, tracking corrections should first be addressed by aligning idlers and checking loading alignment. Pulley skewing is a last resort and must be applied gradually in small increments.

Tail pulley bearings are typically rated for L10 life of 30,000–50,000 hours under rated operating conditions, depending on the bearing selection and mounting arrangement. Because the tail pulley operates at the loading zone — where belt vibration, impact loads, and material spillage are highest — bearing seals and housing protection are particularly important. Contamination ingress is the leading cause of premature bearing failure in tail pulleys, so labyrinth seals and regular regreasing intervals are recommended.

Tail pulleys require periodic inspection of the shell surface for material buildup or wear, bearing regreasing or replacement, seal condition checks, and verification of shaft alignment. Wing pulleys should be inspected for cracked or worn wing segments. Tail pulleys in dirty environments should be checked more frequently — particularly after major material spillage events. The take-up mechanism should be greased and checked for correct belt tension, as slack belt at the tail is a common cause of mistracking and spillage.