Abstract: The friction self-excited vibration system model with the plastid-spring-conveyor belt based on the Stribeck friction model was built to study the stick-slip kinetic characteristics of machine feed system. The stability of equilibrium point of self-excited vibration system was analyzed through the Lyapunov stability criterion， and the critical instability speed of the system was obtained， and then the critical stick-slip speed of the system was deduced from the theoretical formula. The phase diagram and the Poincare section diagram through the numerical simulation show that with the increase of machine feed rate， damping and stiffness of transmission and with the decrease of dynamic-static friction difference， the duration of stick-slip will be shorter， and the stability of the system increased. The self-excited vibration with low speed condition is divided into stick-slip and pure sliding， and they are both periodic motion. The feed velocity is important for the stability of the system.

Key words: Stribeck friction model, dynamics, stability analysis, self-excited vibration, numerical simulation