Analysis of Strength and Fatigue Life of Breaker Detent

The detent is an important component that affects the reliability of the spring operating mechanism of the circuit breaker. Three-dimensional modeling of opening detent, closing detent, energy storage retention detent and closing retention detent is carried out based on COMSOL. The stress conditions of them under the two working conditions of closing spring energy storage state and closing holding state are analyzed, and the corresponding stress and strain distributions are obtained through finite element calculation. The fatigue life analysis based on the S-N curve shows that the closing detents, opening detents and energy storage retention detents will not suffer fatigue damage, and the minimum fatigue life of the closing retention detents is 1.74×10⁴ times, which meets the requirements of mechanical life of circuit breaker operating mechanism.