Tooth shapes come in many forms, of which involute teeth are the most common. There are two commonly used processing methods for involute tooth shapes, namely the forming method and the unfolding method.
1. Milling teeth
The use of disc modular milling cutters or finger milling cutters to mill teeth belongs to the forming method of machining, and the cross-sectional shape of the cutter teeth of the milling cutter corresponds to the shape between the gear teeth. This method has low machining efficiency and machining accuracy, and is only suitable for single-piece small batch production.
2. Forming teeth grinding
It also belongs to the forming method processing, because the grinding wheel is not easy to trim, and it is used less.
3. Gear hobbing
It belongs to the unfolding process, and its working principle is equivalent to a pair of helical gear meshing. The prototype of the gear hob is a helical gear with a large helical angle, because the number of teeth is very small (usually the number of teeth z = 1), the teeth are very long, and a worm with a small spiral lift angle is formed around the shaft, and then after slotting and shoveling teeth, it becomes a hob with a cutting edge and a rear angle.
4. Shave your teeth
Shaving teeth in high-volume production is a commonly used finishing method for non-hardened tooth faces. Its working principle is to use the shaver and the gear to be machined for free meshing movement, with the help of the relative slip between the two, shave off a very fine chip from the tooth surface to improve the accuracy of the tooth surface. Shaving also forms drum-shaped teeth to improve the position of the contact area of the tooth surface.
5. Teeth insertion
Tooth cutting is a commonly used tooth cutting process using the unfolding method in addition to gear hobbing. When the teeth are inserted, the tooth cutter and the workpiece are equivalent to the meshing of a pair of cylindrical gears. The reciprocating motion of the tooth insert is the main movement of the tooth insert, and the circular movement of the tooth cutter and the workpiece in a certain proportion is the feed movement of the tooth insert.
This picture is not intuitive enough to see, this is difficult to xiaobian, the following schematic diagram everyone should understand at a glance.
6. Grinding teeth by unfolding method
The cutting motion of the unfolding method of grinding teeth is similar to that of rolling teeth, and it is a toothed finishing method, especially for hardened gears, which is often the only finishing method. The unfolding grinding method can be ground with a worm grinding wheel, or it can be grinded with a tapered grinding wheel or a disc grinding wheel.
The above figure is in order a. tapered grinding wheel grinding teeth, b. butterfly grinding wheel grinding teeth, c. worm grinding wheel grinding teeth.