Carrying Idlers (Troughing or Flat)
Support the belt in the section of the conveyor that transports the material. These may be flat, or 20 degree, 35 degree, and 45 degree troughing types of equal or unequal roll length. (Unequal rolls are used where magnetic separation, picking, etc., is required).
Prevent damage to the belt at the loading point. These idlers may be troughing or flat types with grooved, molded rubber rolls. It is standard practice to use impact idlers at all loading and transfer points when the impact force exceeds 40 foot pounds.
Support the empty belt between the discharge point and the tail pulley.
a. Standard – Used where materials are not sticky, corrosive, or abrasive.
b. Spiral – Used where sticky materials adhere to the best, where a corrosive environment is present or abrasive wear is a problem. Their unique construction minimizes belt fleet and damage to the return belt due to material buildup on the on the idlers roll. Spiral roll idlers can be used for belt travel in one direction only.
c. Disc return – Used under the same conditions as the spiral idler. These idlers can be used for belt travel in either direction. Masses end discs are standard.
Carrying Belt Training Idlers (Troughing or Flat)
Assist in keeping the belt centered on the conveyor. Actuating shoe type is used on belt traveling in either direction. Positive type is used on belt traveling in one direction only and is illustrated.
Return Belt Training Idlers
Used for the same purposes as are Carrying Training Idlers. They are of the actuating shoe type, belt travel – either direction, and the positive and inclined pivot types, belt travel – one direction only. The positive type is illustrated.
Return Belt Tracker
This idler uses off-centered belt weight for belt training instead of gross belt displacement. A Rex self-aligning flanged bearing within the roll shell is used for the pivot. The ribbed rubber cover helps eliminate material buildup. This idler can be used for belt travel in either direction.