Abstract
The simulation program developed that calculates the clearance between cutting edge of hob and tooth flank of gear blank is applied to some practical industrial problems of dry hob cutting, i.e. to chipping failure of cutting edge of carbide hob and bad coarse surface finish of hobbed tooth flank of product gears. The output of the simulation explains the mechanism of such actual failures in detail. The "Distance of Single Edge Cutting" of a hob tooth is proposed to be an index of chipping failure of hob cutting edge due to chip intrusion into the clearance between hob cutting edge and tooth flank of gear blank. Combination of DTL and LRC condition is found to be an index of rough scratched hobbed flank due to chip intrusion. Influencing factors on it is investigated and the bases for finding countermeasures are shown. This method has been applied to some practical cases of problem in mass-production of automotive gears, and good result was confirmed.
