Tread Design For Independently Rotating Wheel

The road-rail vehicles are more and more concerned as economical tration by lots of railroad customers with the development of the economy. The way to realize that is to use the independently rotating wheels(IRWs).Comparing with the conventional fixed wheelset, the IRW don't engender longitudinal creep force, so hunting won't occur and the stability of vehicle system is very good. But IRW loses self-steering capability of longitudinal creep moment, so its restoration capability and curving performance becomes worse. The purpose of this paper is to design an appropriate tread shape for IRW.The paper discusses the design program of the MDL tread. The wheel and rail contact relationship can be get through a SIMPACK processing procedure before the MDL tread and the 60kg/m rail data should be made into a document according to the SIMPACK format request. Meanwhile, the DDB tread JXDL1 tread and JXDL2 tread models were builted in order to compare with the MDL tread. The parts'gravity center and mass were gained by building up the road-rail vehicle model. A vehicle system dynamic model was established by utilizing the multi-body system dynamic software SIMPACK. Then the dynamic simulation caculation was performed. The dynamics performance were evaluated.The conclusion shows that the contact angle difference of the MDL tread which increase slowly is favor of ensuring the stability when the horizontal movement is small in 4 mm. It will increase quicly as continued horizontal movement and attain the greater than the DDB tread used. So we can get more gravity restoring force. We can get the conclusion that the design of the MDL tread is more reasonable and it can get better riding quality, center capability in straight line and curve passing performance according to analysis the vehicle dynamics with 4 kinds of treads.