Abstract：With the continual improvement of locomotive speed, higher requirements on the stability and operating safety of locomotives have arisen.The rotor dynamic model of a transmission system, was stuclied, taking into account the composite factors fault feature such as the bear and gear mesh stiffnesses.First, the rotor dynamic model of the transmission system was built，taking into account the factors such as the rotor, gear mesh stiffness and bearing support stiffness.Next, according to the types of locomotive components’ fault features, the local fault feature expressions for the gear and bearing were derived.Then, the amplitude and frequency characteristics were verified numerically, and the transmission characteristics of the signal energy and correlation of the system were explained when there were local fault defect in the system.
