An idler on a conveyor primarily serves to

• A. Engage the belt drive
• B. Change belt direction
• C. Store electrical energy
• D. Provide additional support to the belt

Answer: (D)

An idler’s main job is to support the belt along its path and help it track properly. By placing rollers under or along the belt, an idler carries the belt’s weight and helps keep it flat, reducing sag between supports. That keeps the belt aligned with the pulleys and prevents edge wear, snagging, or rubbing on the frame. With proper support from idlers, belt tension stays more uniform and power is transmitted more smoothly, which extends belt life and reduces operating problems.

This isn’t about driving the belt, which is done by the drive pulley and motor, nor about changing the belt’s direction—that’s handled by bend or redirect rollers. It also isn’t about storing energy; idlers are passive components that simply support the belt.