Reasons for gear damage in wind turbine gearbox

During the operation of a certain type of fan, the third stage planetary gear in its speed increasing gearbox experienced severe peeling. The reasons for planetary gear peeling were analyzed by macroscopic observation, chemical composition analysis, metallographic examination, hardness testing, scanning electron microscopy analysis, precision testing, and maintenance analysis. The results show that the tooth surface hardness, internal oxidation depth, martensite level, residual austenite level and other indicators of the third stage planetary gear did not meet the design requirements. The poor heat treatment quality reduced the tooth surface contact strength, shortened the service life of the gear, and ultimately led to the peeling phenomenon of the third stage planetary gear tooth surface.