ASM Failure Analysis Case Histories: Construction, Mining, and Agricultural Equipment
Failure of a Hoist Gear Assembly Shaft from a Mobile-type Crane
A shaft, which carried both a worm wheel and hoist barrel, fractured at a reduction in diameter adjacent to a mating gearbox. The appearance of the fracture was characteristic of a fatigue failure of a rotating shaft resulting from excessive bending stresses. Cracks of the fatigue type broke out all around the circumference at the change of section and progressed inwards. Microscopic examination of the material showed it to be an alloy steel in the hardened and tempered condition, with no abnormal features. It was considered that the bending stresses due to the deflection of the shaft arising from misalignment were responsible for the fatigue failure, which occurred in a region of stress concentration where insignificant fillet radius had been provided.
Failure of a Hoist Gear Assembly Shaft from a Mobile-type Crane, ASM Failure Analysis Case Histories: Construction, Mining, and Agricultural Equipment, ASM International, 2019, https://doi.org/10.31399/asm.fach.conag.c9001466
Download citation file:
New Handbook: Volume 11B
Now available in the Digital Library! Volume 11B serves as a reference and guide to help engineers determine the causes of failure in plastic components and make corrective adjustments through design and manufacturing modifications.