AGMA 06FTM12 PDF

The gearboxes used in cranes have proven themselves to be reliable. However, some gear failures have caused a reevaluation of the design, configuration, and manufacture of gearboxes in large cranes. Since crane gearboxes do not operate continuously, gear system fatigue characteristics have not been in the forefront of system operation. Studies have indicated that in many cases usage rates, loading, and in many cases both, have increased. In some applications, crane usage has increased by factors of two, or three, or even more, and gear loading has similarly increased. This higher usage makes the cumulative effects of fatigue much more important. This paper presents a case study of one particular crane gear failure, including failure analysis and resultant remedial actions, along with a discussion of the results and implications from extensive gearbox inspections that were conducted as a result of the initial failure.