There are three aspects to consider when designing the tip radius:
(1) No interference occurs in the running process of gear pair;
(2) The radius of the fillet on the blade can be manufactured;
(3) The non-working surface of the blade will not scratch the opposite tooth surface.
Increasing the coefficient of tooth height and the top pitch of large wheel cutter will decrease the width of bottom groove of small wheel, decrease the radius of radius of radius of small wheel cutter tip and cause stress concentration of root.
If the radius of the small wheel cutter fillet is too small to increase the end coincidence, the bending stress of the small wheel root may increase significantly and the bending fatigue life will be reduced instead.Therefore, the tooth height coefficient and the tool crest distance should be reasonably selected according to the radius of the small wheel tip so as to minimize the bending stress of the small wheel root.