Based on the infulence factors of strength caculation on wind turbine gearbox

the choice method of material & heat-treatment in common use of wind turbine gearbox is discussed

and calculation factors heat-treatment in gear strength caculation are analyzed.In addition

the effects of heat-treatment on application factor and life factors under variable loads are investigated.The recommended case-depth values of carburized gear and nitrided gears are given

and attentions to selection of fatigue allowable stress numbers and minimum safety factor of various wind turbine gearboxes are also listed.