Machining Principle and Application of Hobbing Method for Small Module Gears

The machining principle and application description of the small module gear hobbing method are as follows, for reference and understanding.

Hobbing principle:

Gear hobbing is the most widely used gear processing method.The rolling method is also called the spreading method or the fanning method.It uses a generating tool with a conjugate tooth profile with the workpiece to force a meshing motion with the workpiece to form the required tooth profile of the workpiece.

The rolling method is equivalent to a pair in principlehelical gearClosely spaced, the gear hob is equivalent to a helical gear with very few teeth. A number of grooves are opened in the axial direction, and the corresponding clearance angle is shoveled on the back of each tooth, so it can be Cutting is performed during meshing.

Since the spiral lead angle of the small modulus gear hob is very small, the gear melting process can also be regarded asgear和rackIn the meshing process, each row of teeth of the hob is regarded as a rack, and these racks are separated by an equal pitch, and are arranged on one (single-head hob) or several (multi-head) spiral lines.

During the cutting movement, it is equivalent to that the rack moves tangentially along the workpiece, and meshes with the workpiece to roll out the workpiece tooth profile.Therefore, during the hobbing process, there must be an included angle between the hob axis and the workpiece axis. This included angle is called the installation angle.

The hobbing movement includes: hob cutting movement, workpiece indexing movement, hobbing axial movement and workpiece indexing movement.

Gear hobbing can process not only involute tooth profile, but also non-involute tooth profile such as modified cycloid profile, arc profile for timing instruments, double arc profile, etc.

When hobbing an involute gear, changing the position of the hob and the gear blank center can roll out various shifted gears, and when hobbing the correct cycloid and the arc gear for timing instruments, the axis of the hob and the gear blank The position is fixed and immutable, so there is no concept of gear shifting.

The hobbing method can process spur gears, helical gears, and bevel gears, as well as various worm gears.

The above small modulus gear hobbing method processing principle and application instructions, including but not limited to, if you have any unclear points or related requirements, you can consult EP free of charge.