| 【文章摘要】 This paper presents a study on bending fatigue strength of three kinds of induction hardened gears(pressed structure gears,solid gears and laminated structure gears)assembled with vehicle’s engine flywheel.Hardness measurements of hardened layers and bending fatigue tests were carried out for these test gears,effective hardened depths and S-N curves were obtained.O n the basis of these results,the effects of the heating conditions(electric power and heating time)and the tempering on effective hardened depth and the bending fatigue strength of these gears were clarified to a considerable extent.Furthermore,the results of the induction hardened solid gears and laminated structure gears were compared with those of the pressed structure gears.Based on the previous paper[3],the main conclusions have been shown that the change of the bending fatigue limit load Pnuof the induction hardened pressed structure gears is depending on the heating time th,and the optimum thfor Pnuhas been obtained.T hen in the present paper,the newconclusions have been obtained that the Pnuof the induction hardened S48C steel pressed structure gears is larger than that of the S35C steel pressed structure gears.And the Pnuof the induction hardened pressed structure gears is much larger than that of the solid gears and the laminated structure gears. |