Study On Friction And Wear Rate Of Sliding Electrical Contact Of Pantograph-catenary System Under Fluctuating Compressive Load

In the operating process of train,the compressive load of pantograph-catenary system is fluctuating in a form similar to the sine wave.In addition to the operating speed and current density,the variation of the fluctuating compressive load will have a significant impact on the friction and wear rate of the sliding electrical contact of pantograph-catenary system,which will affect the safe and efficient operation of the train.In this paper,the fluctuant state of the compressive load of pantograph-catenary system was simulated by the pin-on-disk experiment machine.The influences of constant normal load,operating speed,current density,fluctuating amplitude of compressive load and fluctuating frequency of compressive load on friction and wear rate are studied.And the influence mechanisms are analyzed.Characteristic laws are as follows.The increase of the constant normal load will lead to the increase of the friction.The increase of amplitude of fluctuating load and the increase of the operating speed will lead to the increase of the friction and wear rate.The increase of the current density will lead to the decrease of friction and the increase of the wear rate.The change of the frequency of fluctuating load has no obvious effect on the friction and wear rate.When the current density is constant,the wear rate is positively correlated with the friction.It can be found that amplitude of fluctuating load,operating speed and current density are main influencing factors of wear rate and friction of sliding electrical contact of pantograph-catenary system.The influence mechanisms are as follows.Roughness of pin surface caused by arc erosion and mechanical wear are main reasons for increase of wear rate and friction.High temperature makes the material more easily worn out,but its lubricating effect makes the friction smaller.And the mathematical model of the friction with the normal load,the operating speed and the current density is constructed by obtained characteristics.The validity of the model is verified by the historical data method.In this paper,through the simulation of the actual operation of the pantograph-catenary system,the friction and wear rate under the fluctuating compressive load are deeply analyzed,which provides a theoretical guide for the study of how to reduce the friction and wear of pantograph-catenary system.