To solve the problem that rolling bearing in a circuit breaker is easy to be worn down

a FEM equation of colliding problem is established

and 3D solid models of cam-bearing mechanism are created in UG environment and are embedded to ANSYS/LS-DYNA.By using the kinematic and dynamic simulation functions of LS-DYNA

the contacting force

stress distribution

and stress concentration in colliding process of cam and bearing are computed and simulated

and the causes of rolling bearing failure are analyzed.Simulation result shows that this method is very effective to analyze and simulate transient colliding process of cam and rolling bearing in circuit breakers.