The gear hobbing hob with modulus of 2, number of grooves of 12 and number of heads of 2 is used for simulation test with different outer circle diameters, and the relationship between the outer diameter of gear hobbing hob and the effective tooth length of gear hobbing hob is obtained as shown in the figure.
(1) When the diameter of the outer circle is 95mm, the effective tooth length of the cutter tooth is 5.9mm It can be grinded for 19-20 times;
(2) When the diameter of the outer circle is 65mm, the effective tooth length of the cutter teeth is 3mm It can be grinded for 8-10 times.