Gear processing is a wheeled mechanical part that transfers torque by meshing of teeth. Gear processing can change the speed and torque, change the direction of motion and change the form of motion by driving with other gear-like mechanical parts. Because of the advantages of high transmission efficiency, accurate transmission ratio and wide power range, gear mechanism is widely used in industrial products. The pinion of the gears to each other will drive another gear to rotate to transmit power. Separating the two gears can also use chains, crawlers and belts to drive the gears on both sides to transmit power.