Belt drive has the characteristics of simple structure, stable transmission, buffering and vibration absorption, power transmission between large axle spacing and multi-axes, low cost, no need of lubrication, easy maintenance, and so on. It is widely used in modern mechanical transmission. The friction type belt transmits kinetic energy overload, slipping, low running noise, but the transmission ratio is not accurate (the sliding rate is less than 2%); The synchronous belt drive can ensure the transmission synchronization, but the absorption capacity of load change is slightly poor, and there is noise during high-speed operation. In addition to transmitting power, belt drive is also sometimes used for conveying materials and arranging parts.