Ribbed-belt drive

When designing a multi-ribbed (poly-v) belt drive, the engineer most often uses tools supplied by belt manufacturers: paper or electronic catalogs, calculation notes and on-line or downloadable software. This approach provides a very quick solution, but largely masks the calculation method used, and consequently fails to consider and understand the phenomena involved. In addition, the mechanical characteristics of the recommended belt, although necessary for a number of calculations, are not always provided. What's more, the calculation notes concern simple cases and are not valid for n-pulley transmissions. The aim of this article is therefore to provide the reader with precise explanations of how to calculate a multi-ribbed belt drive in general cases. Essential data such as belt length, belt strand lengths, installation tension and belt strand tensions during operation are calculated. The determination of rotational resonance frequencies and transverse vibrations is explained and simplified. The use of means for measuring longitudinal and bending stiffness, as well as pulley-belt slip, is explained. The aim of this article is to enable the reader to understand the essential points in the calculation of a multi-ribbed belt drive in order to optimize its operation.

This article is the first part of the "Ribbed belt drives" dossier and is linked to the second part entitled "Nonlinear dynamics and behavioural instabilities" [BM 5 691] .