Failuress of Involute Gears due to Contact of Side Edge and Tip Edge of Tooth: 4th Report, Failure Caused by Trochoidal Interference due to Elastic Deformation of Tooth

Under heavy loading, lower boundary of contacting area on tooth flank of gears with small amount of profile modification can be trochoidally interfered by tip edge of mating tooth, because of large tooth deformation. Pits appear in that interfered area and can cause large surface failures like spalling or flaking. In this report, failures due to trochoidal interference are investigated in detail : Plastic flow and wear of tooth flank of several micron meters are observe in the interference zone in dedendum. The damage is clearer near tooth root of driving gear, compared with that of driven one. On the other hand, interfering tip edge is not damaged severely. Corner rounding of tip edge softens the failure condition due to trochoidal interference but the effect is limited. Simulation method for contacting state of helical gear teeth with tooth form modification considering trochoidal interference is developed.