Selecting an idler starts with the strand, not the catalogue name. First, say whether the idler sits on the carrying strand or the return strand, because carrying idlers, troughing idlers and return rollers do different jobs. Then say whether the belt wanders, whether material spills at the edges, and whether the loading point damages the belt, because each of those symptoms points to a different part of the idler family. A self-aligning idler answers a tracking symptom, a troughing set answers a spillage symptom, and an impact roller answers a loading symptom, and mixing those answers up wastes money.
Next, describe the belt and the material. Belt width decides the frame size, and the material decides the duty: heavy, abrasive material asks more of a carrying roller than light material, and sticky material asks more of a return roller. State the belt width, the material and the belt speed in the inquiry, and ask the supplier to confirm duty for that combination rather than accepting a family name alone.
Finally, check the set as a set. Troughing idlers work as a centre and wing set, return rollers work along the whole return run, and impact rollers work across a loading zone. Quote the run, the spacing and the spares together, and confirm quantity and delivery in the inquiry. Please confirm the minimum order quantity with the supplier before placing an order. Please confirm the lead time with the supplier before placing an order. Certificates available upon request.
Idler duty at the loading zone
The loading zone is where idler selection is tested hardest, because the belt, the material and the idlers meet there under the worst conditions on the line. Material falls from a chute onto a moving belt, and the idlers under that fall must absorb the shock without letting the belt sag between supports, while the belt cover above them takes the abrasion of every load. A loading zone that is described only by its belt width will therefore be quoted with the wrong idlers, because the drop height, the lump size and the chute alignment all change what the zone needs. Describe the chute as well as the belt: where the material stream lands, whether it lands centrally or off centre, and whether the skirt sealing holds material on the belt or lets it escape at the sides. State whether an impact bed, impact rollers or both are already in place, and describe the wear you have seen, whether it is belt cover cuts, roller shell wear or spillage under the zone. With those facts, the supplier can confirm the loading zone as a whole, including the idlers, any impact protection and the chute sealing, rather than quoting rollers for a zone whose real problem is the chute.
Keeping spares for a whole run
Spares for idlers should be held for a run, not for a single position, because idlers fail across a run and the run is what must keep moving. Start with the longest runs and the loading zones, since a failure there costs the most downtime and is hardest to reach, and hold complete sets rather than single rollers, so a troughing set or a loading zone set can be replaced as a set during a planned stop. Check stored spares before they are fitted, looking for damage from storage and for the correct diameter and shaft arrangement, since a spare that does not match its run is not a spare at all. Record every replacement by position and date, so a run that consumes rollers in the same place repeatedly points to a frame or loading fault instead of being treated as bad luck. Review the spares holding after each major inspection, and top up the positions that were actually used rather than topping up evenly, because usage across a line is never even and an even top-up leaves the hungry positions short.
Brief this line for your project. Tell us the material, the route and the duty you expect, and we will confirm what can be supplied. Send an inquiry