A fundamental decision designers face when building a horizontal carousel is whether to configure it as a top-drive or bottom-drive system. New research indicates a significant difference. A recent study, funded by White Systems Inc., Kenilworth, N.J., shows bearing life to be more than six times greater on bottom-drive than on top-drive carousels. The study compares standard top-drive and bottom-drive carousels by measuring them with load and duty cycles in laboratory and field environments.
Among the conclusions were data that indicated a carousel with a 1,000-lb/bin load traveling at 80 fpm will experience a failure rate of 10% after 1,425 hr on a top-drive machine, while that extends to more than 8,750 hr on a bottom-drive carousel. "The conclusion is that bottom-drive carousels require less maintenance and will outperform topdrive carousels in heavy-duty applications," noted Anthony Balestro, vice president of engineering at White Systems. Bottom-drive carousels are recommended for heavier loads and higher activity levels.