Crack detection and durability assessment of low speed sugar mill gears : final report JCU2S

Abstract

Heavy low speed gearing used by the Australian Sugar Industry is manufactured according to code specifications. These gears fail in several ways with the most common failure modes being the gradual surface fatigue of the contacting teeth due to poor lubrication and sudden tooth fracture resulting from the presence of cracks. Over the last decade, sudden gear failures have cost .the industry millions of dollars. The problem is exacerbated by the unexpected lost production time and cost of gear replacements.

The general goal of this project was to apply fracture mechanics technology to predict the life of cracked gearing under routine operating conditions and to answer questions such as:

• What size crack can be tolerated under existing and alternative loading conditions?

• Approximately how long would it take for a crack to reach the critical crack length?

• How often should a cracked gear be inspected?