Engines and transmissions: A new twist to torsional vibration problems

Each year hundreds of thousands of non-automotive industrial type diesel engines go into equipment systems and machinery used in the mining industry. Many of these applications are trending toward lighter weight engines as new design strategies seek better fuel efficiency through lighter components. More efficient designs also have allowed inline three-, four- and six cylinder diesels to do what used to require V-8 or bigger powerplants. While downsizing may be a blessing in terms of OEM cost containment and user operating economy, it can easily aggravate the relationship between engine and driven equipment in terms of torsional vibration and the resonance that can amplify this vibration to destructive levels. As a result, the dollars saved in fuel economy -- and more -- might well be lost in repair expenses and downtime costs. The purpose of this article is to examine the sources of torsional vibration problems, and to review the important role that coupling technology can play in minimizing these problems as smaller, lighter weight engines become more popular.