When change gear could not be mated for too big ratio of differential change gear,to select suitable teeth number increament to finish hobbing of big prime number helical and straight-toothed gears.

• 滚削大质数斜齿及直齿齿轮,若因差动挂轮比值过大或过小,而不当搭配挂轮时,可以通过选择适当的齿数增量来解决问题。