1. Mechatronics
　　In micro-machines, not only micro-planetary gears [planetary gears: planetary gears] are required to transmit power, but also miniature planetary gear reducers with their own power drive. In other words, the micromachine needs to synthesize a compact gear [gear: gear] transmission from the micromotor and the micro planetary gear reduction unit, so that it has both functions of driving and deceleration. Therefore, an electromechanically integrated gear transmission having the above-mentioned functions is characterized in that the input shaft and the output shaft of this micro planetary reducer are coaxial, and the motor shaft should be connected with its load compactly. It is structurally possible to connect the shaft of the motor to the input of the planetary gear reducer, that is, the shaft of the motor and the gear shaft of the sun gear a are on the same main axis and are connected to each other. The output shaft of the planetary gear speed reducer (integrated with the internal gear e) is the output shaft of the unit, and thus is configured as a built-in gear transmission unit in which the motor and the planetary gear reducer are integrated. It can also be said that the motor and the planetary gear reducer are combined to form a low-speed motor, and its output shaft can be directly connected to the working machine. The key problem nowadays is that in order to realize the practicality of the miniature planetary gear reducer with an electric motor, a practical micromotor having excellent performance comparable to that of the miniature star speed reducer is required. .
　　2. Gear lubrication
　　Gear lubrication in gear transmissions is a very important issue in the development of miniature planetary gear transmissions. Many scholars engaged in tribology research are working to better solve this problem. The lubrication problem of the miniature planetary gear transmission is even more important. According to the relevant literature, in a gear reducer that generally transmits power, the smaller the diameter of the main shaft of the gear reducer, the greater the proportion of the friction torque of its operation in the total power loss. However, in micromachines, it is not an easy task to accurately determine a very small friction torque. However, the ratio of the friction torque of the micro planetary gear reducer to its total power loss can be calculated and increased. At present, people pay special attention to research work in the field of micro-tribology, and look forward to effectively solving the problem of lubrication of micro planetary gear reducers in the near future. It is a great task for the micro planetary gear reducer to be practical. Promote the role.