In the application of modern industrial equipment in high-precision applications, with the development of servo motor technology, from high torque density to high power density, the increase in speed is higher than 3000 rpm. Due to the increase in speed, the power density of servo motor is greatly increased. This means that whether the servo motor needs to be equipped with a reducer is mainly determined from the application requirements and cost considerations. The following applications must be matched with a servo planetary reducer. 1. Heavy load and high precision: This is required when the load must be moved and precise positioning is required. Generally, such as aviation, satellite, medical, military technology, wafer equipment, robots and other automation equipment. Their common feature is that the torque required to move the load often far exceeds the torque capacity of the servo motor itself. This problem can be effectively solved by increasing the output torque of the servo motor through a reducer. 2. Increasing torque: The method of increasing the output torque may be to directly increase the output torque of the servo motor, but this method not only must use an expensive and high-power servo motor, but the motor must have a stronger structure, and the increase in torque is positive. Compared with the increase in the control current, the use of a relatively large driver at this time, the increase in the specifications of power electronic components and related electromechanical equipment, will also greatly increase the cost of the control system. 3. Improve performance: It is understood that improper matching of load inertia is one of the biggest reasons for the instability of servo control. For large load inertia, the inverse square of the reduction ratio can be used to adjust the best equivalent load inertia to obtain the best control response. So from this perspective, planetary gearboxes are the best match for the control response of servo applications. 4. Reduce equipment cost: From a cost point of view, assuming that a 0.4KW AC servo motor is used with a driver, it will cost one unit of equipment cost. If a 5KW AC servo motor is used with a servo driver, it will cost 15 units of cost. However, if a 0.4KW servo motor is used with The drive, with a set of reducers, can achieve the aforementioned 15 unit costs to complete, saving more than 50% in operating costs. Therefore, users decide which planetary gear reducer to choose according to their different processing requirements. Generally speaking, there are occasions requiring low speed, high torque and high power density in machine operation, and most of them use planetary gear reducers.