Gear hobbing is a specialised process of gear cutting, spline cutting and sprocket cutting. The central equipment in the gear hobbing process is the milling machine. This gear hobbing milling machine does the task of cutting the spline or teeth using a series of cuts using a hob. Gear hobbing is often used for spur gear and helical gear making, because of its ease of use and cost effectiveness.

 

The process of gear hobbing is as follows:

 

1. The gear hobbing machine is checked for any mechanical issues. This includes the synchronisation of the rotating gears for the workpiece and the hob.
2. The gear hobbing machine has two skew spindles, one of which has the gear blank while the other one has the hob.
3. The spindles are set at an angle from each other, depending on the type of teeth to be set on the gear blank.
4. The two spindle shafts are then rotated proportionally with the hob cuts on the gear blank. Having them properly rotating is the key to making the right gear teeth on the gear blank.
5. The hob would then be applied to the gear blank until the correct tooth depth has been reached.
6. The hob is then run through the gear blank’s axis of rotation as a final step.
7. The process is repeated for each gear blank, which is often stacked one atop another. The rotation ensures identical gear spindle depth and a consistent number of teeth on each gear blank.
8. The completed gears are removed from the milling machine.

 

The central tool to gear hobbing is the hob, a worm-shaped cutter. The hob makes successive cuts on the gear blank to create the gear teeth. In order for the cutting to be precise, the gear blank and the hob must be synchronised in the rotation.