Abstract: Considering the characteristics that the circuit breaker mechanism system wear data is a small-scale sample, the failure threshold is not fixed and the experiment cost is very high, the simulation test method, the small-scale sample data processing method and random theory are used to research on the wear reliability of the large capacity generator breaker transmission mechanism. On the basis of considering kinematic pair irregular wear on the circuit breaker transmission system and the manufacturing error, the depth of wear on the kinematic pair different contact points is calculated based on Archard wear model, and the wear data under the case that the initial clearances of the dangerous joint kinematic pair in the circuit transmission mechanism follow normal distribution is got through ADAMS simulation software. The post-expansion data is obtained with the methods of the virtual augmentation method and boot-strap method, the reliability function curve before and after expansion of the circuit breaker are got separately according to the distribution law of circuit breaker mechanism system wear amount, the results after comparison show that the small-scale expansion is necessary. The reliability function curves under the cases of fixed threshold and random threshold are obtained separately by using the post-expansion wear data, and the comparison results show that the reliability under random threshold is more close to the actual production. The research indicates that the simulation test can be used to predicate the reliability of the complex wear process, which can avoid the traditional research method relying on the experiment, and the analytical method has certain rationality.

Key words: circuit breaker mechanism, failure threshold, reliability analysis, small-scale sample, wear simulation