Gears can be classified by tooth shape, gear shape, tooth line shape, surface on which the gear teeth are located, and manufacturing method.
1) Gears can be classified into tooth profile curve, pressure angle, tooth height and displacement according to tooth shape.
2) Gears are divided into cylindrical gears, bevel gears, non-circular gears, racks, and worm-worm gears according to their shapes.
3) Gears are divided into spur gears, helical gears, herringbone gears, and curved gears according to the shape of the tooth line.
4) According to the surface gear where the gear teeth are located, it is divided into external gear and internal gear. The tip circle of the external gear is larger than the root circle; while the tip circle of the internal gear is smaller than the root circle.
5) According to the manufacturing method, gears are divided into casting gears, cutting gears, rolling gears, sintering gears, etc.
Gear transmission is divided into the following types:
1. Cylindrical gear drive
2. Bevel gear drive
3. Hypoid gear drive
4. Helical gear drive
5. Worm drive
6. Arc gear drive
7. Cycloidal gear drive
8. Planetary gear transmission (commonly used is the ordinary planetary transmission composed of sun gear, planetary gear, internal gear and planet carrier)