Idler Pulleys

V-Belt Idler Pulleys

AIMS Industrial stocks V-belt idler pulleys and flat idler pulleys from Aetna, Don Dye and Gates for tensioning and back-bending belt drive systems. Correct idler selection and placement is essential for achieving design belt tension, minimising belt stress and maximising drive service life.

V-Groove Idler Pulleys

V-groove idler pulleys in A, B, C, B/C and 5V section engage the top face of the belt to provide outside tensioning. Single row bearing idlers are standard for most applications; double row bearing variants handle higher radial loads on heavily loaded drives. 4-point heavy duty idlers in A, A/B and A/B/C section provide exceptional load capacity for demanding industrial drives.

Flat Idler Pulleys (Flanged)

Flat flanged idler pulleys act on the flat back of the belt to provide inside tensioning. Available in single and double row bearing configurations, zinc plated and plain finishes, and OD sizes from 2-7/8" to 8". Extra heavy duty flanged variants handle high belt tensions on large industrial drives where standard pulleys would be marginal.

Flat Idler Pulleys (Non-Flanged)

Non-flanged flat idler pulleys are used where belt tracking is controlled by the drive geometry rather than the idler flange. Available in single and double row bearing configurations. Gates flat idler pulleys in 4.25" OD are available in 1.25" and 2.00" ID for direct shaft mounting.

Don Dye Idler Pulleys

Don Dye A/B section flat flanged idler pulleys in 4" and 5" OD are a robust option, available in single row and one-side plain steel configurations for drive designs requiring a specific contact surface finish on one face.

Application Notes

Outside idlers (V-groove) should be placed on the slack side of the drive with a larger diameter than inside (flat back) idlers to minimise belt bending stress. Avoid placing idlers close to the drive pulleys where belt wrap would be significantly reduced. Contact our team for drive design guidance.