The Research Of Wheel/rail Contact And Processing Of The Wheel And Rail

The high speed railway transportation for rail has attracted world wide attention and research since the first modern high speed railway—Tokaido Shinkansen operated in the world. Many countries imitated competitively, and then the more high speed railway is in course of building. The world has entered into high-speed development. With the rapid develop of modern high-speed railway , new opportunities brought by the railway transportation. However, with the operating speed of passenger transport of railway improved increasingly, the working condition of railroad wheel/rail system becomes more and more complex. Thus, the serious defects like wear and fatigue between the wheel and rail have caused intensive concern in many countries from the world. These problems cannot be solved without based on the wheel/rail interaction. When the railway vehicles run on transmission lines, the wheel/rail contact provides transfer and movement. In certain degree, the wheel/rail contact determines basic characteristics of the railway vehicles operation. Therefore the study on the wheel/rail contact relation played essential function to development of railway technology.Analysis of geometric relationships is base of the study on the whole wheel/rail contact relation and the core of research on wheel/rail dynamics. That is one of the important factors which influence the quality of running railway vehicles, not only affect the wear and tear of wheel and rail, but also act on safety of wheels on rails and the properties of curve passing through on railway vehicle. Accurate determination of the nonlinear geometric relationships of wheel/rail contact relation is the prerequisite and key of analysis on the effect of other nonlinear factors. The geometric parameters of wheel/rail contact include the left and right contact points on the corresponding shape of wheel and rail respectively, the contact angles (δLandδR) and the generating radius ( rL and rR ) on the both left and right wheels. To avoid the contact between the wheel flange and the steel rail frequently, the distance of wheel flange lateral is lower than gauge, which is also easy for curve passing through on railway vehicle. So wheel can do the transverse displacement and the head shaking angular displacement relative to orbit. Under the different transverse displacement and head shaking angular displacement condition, the contact points between the left and right wheel/rail have different position and the parameters of wheel/rail contact cause corresponding changes. But these parameters are difficult to be taken as explicit formula for the transverse displacement and the head shaking angular displacement relative to orbit immediately. We can build the relation between these parameters and the relative transverse displacement by numerical table and the intermediate value can be obtained via linear interpolation.The movement of wheel on the rail is't pure rolling but existing relative slip phenomena at contact area, these phenomena call creeping slip. The creeping slip is a mode of motion between pure rolling and pure slip, according to interactive slippage direction of wheeltrack, creeping slip can divided into vertical orientation creeping slip,landscape orientation creeping slip and spun creeping slip. The slip will induce in speed difference and the contiguity spot will be formed between two coarctate elastomer. While the rolling element existing relative movement or relative movement trend, creeping slip will be generated at contiguity spot on wheel and rail due to the exist of fricative . The wheeltrack contact force, creeping slip in especial directly determine the size of creeping slip, so the research on creeping slip force is very important. The creeping slip rate and creeping slip coefficient which relating to the size and shape of twain elastomer contact area ( also be distinguished as contiguity spot) determine the creeping slip force, so the study of interaction force, must learn about contiguity theory as well as the calculation procedure of shape and size of contiguity spot first. then we could calculate interaction creeping slip force and creeping slip moment of wheel and rail according to contact area and the relation of creeping slip rate creeping slip.This paper dissertates on the computational rationale of contact geometric relationships and typical wheel tread shape,analyzes and compares the contact geometry conditions of the applications between different types of treads and different types of rail, and the effects on the contact geometry parameters by the r gage and wheel inside distance are discussed. At the contact creeping slip theoretical research, Hertz contact theory and its application on wheel track contact spot area and calculate of contact pressure are expounded, the solution method of creeping slip rate are studied and the effects on the ccreeping slip rate are analyzed. Kalker's linear theory and Shen's non-linear theory are employed to determine creep forces.As the train continuously improved the operating speed,increasing the impact load that the train wheel and rail need withstand and speeding up the wheeltrack damage and endanger traffic safety. In order to guarantee train security,line security as well as travel comfortability, the quality of wheel and rail need meet increasingly strict quality requirements. Incorporate at: (1)Train wheels on the inherent quality, shape and size and precision of appearance need higher requirements;(2)The request of rail purity degree,cross dimensions precision,flatness and surface quality increasingly strict. As a result, study on the forming process of train wheel and rail, promotion on the comprehensive quality of the produce and manufacturing quality is to achieve the best guarantee.According to the advance operating experience and request of the high speed rail and wheel both here and abroad, determine the process. Then the paper focused on the technological process of technology and equipment. through comparing with tradition craft, analyzes it's technical sophistication and yielding economy.