The Medium and Heavy-duty Rotary Tensioners from Fenner Drives, Manheim, Pa. (www.fennerdrives.com), keep proper tension on belts for best drive performance. For medium and heavy-duty applications, the company manufactures two series of tensioners: the RT3000 Series for A and B, and 3V and 5V narrow-wedge belts, as well as J and K section Micro-V belts; and the 4100 and 4900 Series for drives with two to four B/5V belts, one to two C cross-section belts, and multigroove K and M Micro-V belts. They provide from 42 to 85 lb of spring force and can be used with single or multiple belts or strands of chain. They use steel springs and there are no elastomeric tension members to cold flow, fatigue, or take a compression set. The spring also absorbs momentary overloads and reduces vibrations.

Edited by Stephen J. Mraz