There are teeth on the rim that can continuously engage mechanical components that transmit motion and power. Gears are toothed mechanical parts that can mesh with each other, and the application of gears in transmission has appeared very early.At the end of the 19th century, the principle of gear cutting method and special machine tools and tools that used this principle to cut teeth appeared one after another. With the development of production, the stability of gear operation was valued. The role of gears is to transfer the rotation of one shaft to another, and they can also realize actions such as deceleration, growth, change of direction, and commutation.