Rub-impact Behavior Study of a Flywheel Rotor by Considering the Friction Coefficients Effect

High speed rotor is the key equipment of Fly-wheel Energy Storage System (FESS). While the rotor is disturbed, rub-impact between the rotor and the stator would be considered, including the energy dissipating, and the system stability, and so on. In this paper, a set of equations of rub impact process between rotor and stator are established by a plane spring damping model with friction effect. The rotor impact behaviors under different contact stiffnesses and friction coefficients are studied by numerically solved with fourth order Runge-Kutta method. Through this model, it could be found that, under an actual contact stiffness, the stability of the rotor would firstly increase and then decrease with the increasing of the friction coefficient. In other words, for this given contact stiffness, there exists a best friction coefficient value range. This result shows that it is feasible to improve the stability of the flywheel system by optimizing the material and friction coefficient of the rubbing parts.