Failure analysis of air cooled condenser gearbox

(in lingua inglese)

The gears should be case hardened instead of through hardened. Through-hardened gears are typically designed to withstand contact stress of approximately 700 MPa, while, the contact stresses on carburized gears may reach 2100 MPa. Maximum pitting resistance is obtained with carburized gear teeth. The surface finish of the gear should be improved so that ratio of the maximum to average surface roughness is less than 5. Very high value of this ratio indicates that the surface has many peaks susceptible for initial wear tear thus initiating the generation of the wear debris.