Design Harmonic Drive for Application in Robot Joint

In industrial robot design, selecting a motor and reducer is one of the essential elements in the design process. The typical mechanical reducer type is a gear train or planetary gear set. Unfortunately, the gear train and the planetary gear have a meager gear ratio, while their weight is too heavy, the transmission repetition accuracy is low and has a high backlash. On the other hand, the harmonic reducer system developed from the transmission gear has an elastic strain wave, which gives a better gear ratio per weight than those two gear systems. In this paper, a harmonic gear reducer is designed according to the transmission requirements and applied rotation to the base of a Puma 560 industrial robot. The harmonic drive is designed under gear physical requirements and robot techniques properties. The required gear ratio of the rotary joint of 1/50, gear geometry design, manufacturing, calculation, and simulation of strength, the safety factor, and experimental results have verified the designs.