The relationship between the outer diameter of gear hobbing hob and hobbing time Ht is shown in the figure.
Where:
Z2 — number of gear teeth;
Z0 – number of gear hob heads;
A — cut length;
E — cut in length;
B – width of workpiece;
FZ — axial tool travel;
D0 — diameter of gear hob;
V — cutting speed of gear hobbing hob;
The trend seen from the hobbing time formula is:
(1) Increasing the diameter of gear hobbing hob can increase the cutting time;
(2) Increasing the number of gear hobs can shorten the cutting time;
(3) Of course, changing these two parameters will also bring changes to other parameters.
(4) Selecting a small diameter gear hobbing hob can reduce the cutting out and cutting stroke length of hobbing and reduce the cutting man hours.
With a cutting speed of 100M / min, the number of revolutions of the gear hob is 318 revolutions / min for a hob with a diameter of 100mm, and 398 revolutions / min for a hob with a diameter of 80mm, which is 25% higher than that of a hob with a diameter of 80mm. In addition to the influence of stroke length, the processing efficiency of the 80mm gear hob is 28% higher than that of the 100mm gear hob.