Steve Lovell is a journeyman machinist, having learned his trade in Navy and civilian
machine shops, with brief career excursions working as a foundryman and a welder.
Following early years as a craftsman, he held various management positions at Ingersoll-Rand (Pump Group) and the Fuller Company (Minerals Processing), and most recently as director of quality for FLSmidth Minerals. Having worked with more than 30 suppliers of large open gearing on all six inhabited continents, he is an innovator, technical writer, mentor, and recipient of awards in technological leadership. Following retirement from full-time employment in 2010, Lovell remains active today as a consultant for organizations in and around the global mining and cement industries.
Large bevel gears drive the crushing machines used to process ores and minerals in the hard-rock mining and aggregates industries. This paper is intended to help the reader understand the unique aspects of these machines, and why crushing applications fall outside the traditional automotive paradigm for bevel gears.
Large, multi-segmented girth gears do not behave like the relatively compact, rigid, monolithic structures we typically envision when discussing gear manufacturing. Girth gears are very large, non-rigid structures that require special care during the machining of individual mating segments as well as the assembled gear blank itself.