小歯数・大ねじれ角を有するはすば歯車の転造成形（歯すじ誤差の低減）

抄録

The previous paper showed that helical gears with small number of teeth and large helix angle manufactured by form rolling have higher load capacity and more efficiency than hobbed ones. However, they have large deviations on tooth trace. In the present paper, a new method for reducing the deviations is proposed after a mechanism of causing the deviation being realized. As a result, it was found that a periodic fluctuation in the working pitch radius during form rolling process cause the helix deviations. On the basis of the knowledge, a new form rolling method was proposed. This method consists of two processes which give the shift of a half rotation phase of a work-gear to cancel the fluctuation. It was confirmed that proposed method enables to reduce the helix deviation.