Studies on Limiting Load for Scoring of Crossed Helical Gears : Effects of Kind of Material, Heat treatment and Surface Finishing

Abstract

The limiting loads for scoring of the crossed helical gears expressed with Hertzian pressure were compared with those of the FZG spur gear tests and of the roller tests. The limiting loads for scoring of the crossed helical gears are very low and are changed not so widely according to the kind of oil. As a result it can be seen that the crossed helical gear is under quite unfavourable condition for the formation of a lubricating oil film. In order to increase the limiting load for scoring, various kinds of surface heat treatments and material combinations were tested. The load was stepped up from the first stage to the next higher stage successively according to the load stage.