Study on the influence of spring helix angle increase on stress distribution and fatigue life of the operating mechanism

The spring operating mechanism is the key component of the high-voltage circuit breaker, and its split-closing power comes from the self-energy storage of the split-closing spring, so the performance mechanism and fatigue state of the split-closing spring has a great impact on the operation process and dynamic response of the operating mechanism. In this paper, by increasing the coil angle of the spring, changing the spring design material, classifying and modeling the spring, and applying finite element analysis aim to analyze the static structure. The influence of the change of different spring coil angles and materials on the stress distribution of the spring is explored, and the finite element calculation results are imported into the life analysis module to evaluate the life of springs with different helix angles and materials. The results show that under the action of 9 kN working load, after the helix angle is increased by 0.6°, the spring life decreases by 7.23%, the spring life continues to increase by 0.7°, and the overall life of the spring decreases by 12.3%, compared with the initial state. The life decline curve shows an inverse proportional trend.