Failure Analysis of an Overhead Crane Coupling

A failure involving an overhead crane at a copper smelting facility resulted in the unintentional lowering of an approximately 40-ton ladle of molten metal during operation. Inspection revealed damage to the crane’s gear coupling. Chemical and metallographic analysis revealed gear components complying with AISI 1045 and exhibiting impact and wear damage as well as metal smearing of the gear teeth. The gear coupling components were thoroughly cleaned, scanned in three dimensions using a structured light scanner, and then reconstructed digitally in their damaged condition. The interactions of the gear teeth were analyzed digitally for various configurations and engagements of the gear coupling to understand the functionality of the components as a function of wear condition.