抄録
Transmitted load capacity of gear pairs with a combination of Austempered Ductile Iron (ADI) gear and hardened steel one is investigated using a power-circulating type gear testing machine. In ADI gears, four types of gear finishes are conducted, i.e. cermet-finish hobbing (CF), conventional shot-peening (CSP), fine particle shot-peening by air pressure (FSP1) and fine particle shot-peening by water pressure (FSP2). They have different surface integrity on their tooth. Transmitted load capacity is defined as the maximum load at which no failure is occurred, and is related with surface integrity. The relationship among surface roughness, residual stress and hardness is proposed. From the relation, it is explained that FSP1 gear has the highest transmitted load capacity in four types of ADI gears. Furthermore, the failure of FSP1 gear is investigated and it changes from spalling to breakage at high load conditions.