There are two common gear processing principles, profiling processing and fan-to-generation (generating) processing.

1. Profiling. The gear machining tool cuts out the tooth space of the gear, and the "cross-sectional shape" of the tool is the shape of the gear tooth space. When processing gears, there is no gear meshing movement, and the precision of the processed gears is low, and the general accuracy is below 11.

2. Fancheng processing. The gear machining tool itself is a "gear or rack", and the gear hob can be "thinked" as a rack, which is a rack type tool.

During processing, there is a "gear meshing" movement between the gear cutter and the processed gear. Gear cutter tooth profile blade, the motion envelopes the tooth profile (tooth surface) of the gear to be machined. It is an ideal involute and has high machining accuracy. Common ones include gear hobbing, gear shaping, and gear shaving (belonging to finishing) .

1. The forming method of gear processing mainly includes tooth milling and tooth pulling:

(1) Precision cast gears: cheap pinion gears can be processed in large quantities;

(2) Casting teeth of die-casting machine: most non-ferrous metal gears are processed;

(3) Milling machine teeth: can process straight racks;

(4) Gear grinding machine: gears on precision mother machines can be processed;

(5) Gear punching by cold beater: chip-free processing is possible;

2. The generation method of gear processing mainly includes gear hobbing and shaping:

(1) Gear hobbing machine: it can process helical gears with less than 8 modules;

(1) Slotting machine gear shaping: internal teeth can be processed;

(2) Gear shaving machine: is a metal cutting for gear finishing.

(3) Gear shaper: can process large gears with 16 modules;

The main differences between these two methods are:

1. The processing accuracy of the forming method is relatively low, and the processing accuracy of the generating method is relatively high up to level 3;

2. The production efficiency of forming method is relatively high; the production efficiency of forming method is relatively low;

3. The generative method requires gear grinding equipment, and the production cost is relatively high.