抄録
A method of calculating additional motions in form grinding for finishing the gears with the modified tooth surface is proposed. The method can calculate three kinds of additional motions with consideration of changes in the contact line between the grinding wheel and work gear. As examples of calculation, the modifications of tooth surfaces with symmetrical and bias-in shapes are investigated. Consequently, it was found that the improvement by using the three kinds of motions is small in comparison of using the two kinds of motions.