FAILURE ANALYSIS OF THE RING GEAR BEARING IN THE M198 HOWITZER

摘要

The traversing ring gear bearing assembly holds the upper and lower carriage assemblies of the howitzer together. When the ring gear bearing fractured, the gun tube fell to the ground. The failure analysis included destructive testing of the original gear and four additional gears to properly determine the cause of the fracture. Some fasteners holding the ring gear bearing assembly together failed due to hydrogen embrittlement but the cause of failure of the ring gear was stress corrosion cracking.