Applications of Hobbing

Hobbing is widely used to produce spur, helical gears, worms and worm wheels. It can also be used for producing internal gears for which the machine should have facility for fitting a special head. Hobbing cannot be used where gear is to be produced close to the shoulder having diameter bigger than the root diameter of the gear. Double-helical gear can be hobbed if there is sufficient gap between the helices for the hob over travel. This process is not suitable for producing gears of the type shown.