In one micro machine, not only micro transmission device that can transmit power-a micro planetary gear reducer, but also a micro planetary gear reducer with self-drive power device is required. That’s to say, the micro machine needs compact gear transmission device composed of one micro motor and one micro planetary gear reduction unit, so that it has two functions of driving and reduction transmission. Therefore, the feature of the mechatronic gear transmission with 2 functions mentioned above is that : the input shaft and output shaft of the miniature planetary reducer have coaxiality, and the motor shaft should be tightly connected with its load. The shaft of the motor can be connected with the input of the planetary gear reducer on structure. That is, the shaft of the motor and the gear shaft of the sun gear are located on the same main axis and connected to each other. The output shaft of the planetary gear reducer (connected as a whole with the internal gear) is the output shaft of this combined unit then constitutes a built-in gear transmission in which the electric motor and the planetary gear reducer are combined. You can say that the motor and the planetary gear reducer are combined into one low-speed motor, and its output shaft can be directly connected to the working machine. The key problem now is : in order to make this kind of miniature planetary gear reducer with electric motor to be practical, it must to have a miniature motor with excellent performance and practicality that is similar to the size of the miniature planetary reducer. People are contributing to work harder to make the miniature planetary gear reducer further miniaturized.
2. Gear lubrication
The problem of lubrication in gear transmission is an extremely important problem in the development of miniature planetary gear transmission. Many scholars engaged in tribological research are making efforts to better solve this problem. The lubrication of the micro planetary gear transmission is even more important. According to related documents and research, in general power transmission gear reducers, the smaller the diameter of the main shaft of the gear reducer, the greater the proportion of friction torque in the total power loss. However, it is not easy to measure very small friction torque for one micro machine. However, the proportion of the friction torque of the miniature planetary gear reducer in its total power loss can be calculated and it’s increased. At present, people are paying special attention to the research in the field of micro-tribology, and it is expected to effectively solve the lubrication problem of the micro planetary gear reducer in the near future, which will make the micro planetary gear reducer practical and promote its’ development rapidly.
It can be expected that the miniature planetary gear reducer will definitely develop and be successfully and widely used in mechanical engineering in the future.