Gear rack is usually machined by cutting. The cutting method of gear teeth can be divided into profiling method and generating method.

1. Profiling

The profiling method is to use the disc milling cutter or finger milling cutter with the same shape as the gear tooth slot to process on the milling machine.

2. Fanchengfa

The generating method is also called generating method. It uses the meshing principle of gear to cut the tooth profile. This method has high precision in gear machining, and is the main method in gear machining at present. There are many kinds of Fan Cheng methods, such as gear shaping, gear hobbing, shaving, gear grinding, etc., among which the most commonly used are gear shaping, gear hobbing and shaving

And grinding teeth are used for occasions with high precision and finish requirements.

● gear shaping, as shown in the figure below is the case when gear is processed with gear shaper, in which 1 is gear shaper and 2 is gear blank to be processed. The shape of gear slotting cutter is similar to that of gear, and its modulus and pressure angle are similar to that of machined gear. The gears are the same. During machining, the gear shaper cutter moves up and down along the axis of the wheel blank. At the same time, the transmission system of the machine tool strictly guarantees the meshing relationship between the gear shaper cutter and the wheel blank. When the gear tooth profile is cut in this way, the envelope line of each position of the gear shaper blade relative to the wheel blank in the process of movement is shown in the figure (lower right).

When the number of teeth of gear shaper increases to infinity, its base circle radius becomes infinity, the profile of shaper becomes straight profile, and gear shaper becomes rack shaper 1, as shown in the figure below.

● gear hobbing, the gear processing method is based on the principle of gear and rack meshing, using the hob to process the gear teeth on the gear hobbing machine, as shown in the following figure.

The profile of hob 1 is similar to that of a spiral with a longitudinal groove, and the tooth profile of its axial section is the same as that of the rack. When the hob turns

It is equivalent to that the imaginary rack moves continuously in one direction and the wheel blank has two phases

When the gear is meshed with the rack, the hob can cut the involute profile on the wheel blank according to the forming principle. Simultaneous knife

It also moves slowly along the axial direction of the wheel blank, so as to cut out the tooth profile of the gear along the entire axial tooth width.