Abstract: Based on the failure mechanism of nitrogen gas spring fracture of industrial robot, through the use of various advanced failure analysis methods, metallographic structure analysis, material composition analysis, simulation analysis, SEM morphology analysis and other aspects of analysis and verification, it is finally confirmed that the main reason for the fracture of nitrogen gas spring of industrial robot is: the preload (transverse force) on the threaded connection of nitrogen spring Under the action of alternating load stress, the biaxial high cycle fatigue fracture of nitrogen spring occurs. The research results of this paper provide a certain preventive significance for the design and installation process of nitrogen spring, and also provide a certain guiding significance for the analysis of metal material fracture parts.

Key words: Industrial robot, Nitrogen spring, Fracture, Stress, High cycle fatigue