There are many types of gears, and the most common classification method is based on the gear axiality. Generally, they are divided into three types: parallel axis, intersecting axis and staggered axis: Parallel axis gears include spur gears, helical gears, internal gears, racks and helical racks. Intersecting axis gears include straight bevel gears, spiral bevel gears, zero-degree bevel gears, etc. Staggered axis gears include staggered axis helical gears, worm gears, hypoid gears, etc. Pin gears are mainly used in some specific mechanical transmission systems, such as instruments and meters, small mechanical devices, special transmission mechanisms, etc. In some occasions with high requirements for transmission accuracy, limited space or special transmission ratios, pin gears can be used as an effective transmission solution. Gear shaving is an efficient gear finishing method, which was first used in the United States in 1926. Compared with gear grinding, gear shaving has the advantages of high efficiency, low cost, and no burns and cracks on the tooth surface. Therefore, it is widely used in the processing of gears for mass-produced automobiles, tractors and machine tools. Spiral bevel gears and hypoid gears are widely used in the drive of automobiles, tractors, engineering machinery, oil and geological drilling rigs, tanks, helicopters and machine tools. The design and manufacturing quality of this type of gears mainly depends on two factors. One is the accuracy of the processing equipment and its fixtures. The other is the tooth profile accuracy guaranteed by the adjustment parameters of the machine tool and the tool determined by the complex conjugate calculation, which is the key to improving the quality of this type of gears.