Premature failure modes prevented by Moventas upgrades are verified in DigitalClone Softwar
One wind industry challenge has been premature failures in the GE 1.5 gearboxes which are driving unexpected downtime and increased costs. The industry is seeking solutions to reduce future failures.
A 2-row arrangement integrated cylindrical roller bearings (CRB) PL-gear bearings is used in the Extra Life gearbox instead of a 4-row arrangement of conventional gearboxes. Fatigue life simulations (2,000) were conducted in DigitalClone to compare the Moventas 2-row planet gear bearing versus conventional 4-row bearings. The planet bearing showed better load carrying capacity against conventional bearings due to lower contact stress. Results showed an 8% reduction in contact stresses.
A solution
To solve these failure modes, Moventas developed upgrades for the GE 1.5 gearboxes. The Extra Life gearbox is intended for any type of gearbox being replaced to reduce future failures. Sentient Science validated the technology advances and life extension claims for the owner-operator community and quantified the improvements in performance, durability, and reliability.
Results
Computational testing shows an overall gearbox life improvement by a factor of four fold. The life extension achieved was due to improvements made to the case carburized ring gear, integrated planet gear bearings, high speed stage bearings, tooth surface roughness, and material specification upgrades in bearings and gears.
Key factors in the analysis accounted for in DigitalClone computational modeling are the material quality, surface roughness, and stresses based on full gearbox model subjected to real turbine operating conditions, which aren’t accounted explicitly in industry standards.
Filed Under: Gearboxes
