Poly-V Sheaves

Poly-V sheaves run multi rib belts that combine the flexibility of a flat belt with the grip of a V-belt, allowing smaller diameters, higher speed ratios, and smoother running than classical V drives. This collection stocks J section sheaves from 1.5 to 19 in outside diameter in machined steel, in bored to size and bushing mounted styles.

J section is the standard for appliance, HVAC, machine tool, and compressor drives. Match the rib count of the belt to the grooves of the sheave, or run a narrower belt on a wider sheave when the application allows. Product pages cross to TB Woods® and Mitsuboshi equivalents.

Frequently Asked Questions

What is a Poly-V belt drive?

A drive using a thin, multi ribbed belt running in matching grooved sheaves. The many small ribs grip like multiple tiny V-belts while the thin cross section bends around small diameters, enabling compact, high ratio, smooth drives common in appliances, HVAC blowers, and machine tools.

Does the belt rib count have to match the sheave grooves?

The belt may have fewer ribs than the sheave has grooves, but never more. Running a 4 rib J belt on a 6 groove sheave is fine; the unused grooves stay empty. Center the belt and keep alignment tight, since Poly-V drives are less tolerant of misalignment than classical V-belts.

What does J section mean?

The rib profile size. Poly-V sections run from small to large; J section ribs are 3/32 in apart and dominate fractional through low integral horsepower equipment. Match the section letter on the existing belt or sheave.