A challenging problem: the dynamic analysis of a high precision reduction gear

High precision reduction gears are used in the many industrial robots around the world. In order to respond to increasing demand for high durability under higher loads within a limited space, Nabtesco has been striving to analyze the whole assembly of high precision reduction gears for industrial robot arm joints. Initially, an analysis under static load (torque) was attempted using Abaqus/Standard for a whole assembly model with several hundred contact points. The result provided us with important data like stress distribution and the maximum contact stress, factoring in the elastic deformation of all the parts. These results were presented at AUC 2007. As the next step, an attempt was made to analyze the same gear assembly model under dynamic load during the robot arm operation using Abaqus/Explicit. The results revealed the practical behavior and stress distribution of each component based on the local dynamic deformation, especially notable was a sharp hike in the stress due to starts and stops of the robot arm operation. A groundbreaking analysis of an emergency stop was also performed. This analysis also rendered some important findings. This analysis of the dynamic state of a high precision reduction gear is clearly an unprecedented achievement and indicates that Abaqus/Explicit has significant potential to be utilized as the ultimate analysis tool for general machine motion.