An idler is a non-powered rolling component used to support a conveyor belt on either the carry or the return side of the conveyor. Idlers fail or seize when the idler is clogged or buried under fugitive material that has fallen from the conveyor belt.
Failed idlers create a number of safety risks, especially during the replacement of idlers. Replacing failed idlers often involves working from heights, working in exposured areas increasing the risk of heat stroke, and working in confined spaces. To remove an idler, the idler frame must be removed from the belt, and are typically heavy especially with the added weight of the conveyor belt, which increases manual handling risks.
Removing frozen or seized idlers is essential as exposure to seized idlers creates additional stress on the conveyor drive motor, and increased wear of the conveyor belt.
Friction between the frozen idler and the conveyor belt wears away the case of the idler creating sharp edges, which in turn causes damage or excessive wear to the belt, shortening conveyor belt life considerably and increasing replacement costs.
To increase the life of idlers, a conveyor belt must reduce spillage and carry back that wears and clogs the conveyor idler. This includes correct belt tracking, effective sealing systems, and belt cleaning system to reduce carryback. All these devices require consistent and involved maintenance and monitoring to ensure optimum efficiency.
Idlers will eventually seize or break down. To combat the difficulty and time taken in changing an idler, change outs should be replaced with retractable idler frames, which allow for the easy removal of idlers as it disengages them from the belt. This reduces the effort needed to slide the idler out for replacement.