Simulation Of Temperature Field Of Pantograph Friction Pair Under Dynamic Contact Pressure

The temperature rise characteristics of the pantograph catenary system will affect the material characteristics of the friction pairs and accelerate the wear of the system.In order to reduce the influence of temperature field on pantograph catenary system and the wear caused by temperature rise,the transient temperature rise and distribution of copper / copper impregnated carbon friction pairs were investigated under dynamic contact pressure.Based on the simulation model established by COMSOL Multiphysics,the validity of the simulation model was verified by comparing with the experimental results of temperature rise.On this basis,the steady and transient temperature rise characteristics of friction pairs,the process of temperature establishing inside the material and the contact surface and the time varying law of temperature distribution were studied under the dynamic contact pressure.The results show that: The steady temperature rise of the friction pair decreases first,then increases,while the thermal time constant decreases gradually with the increase of speed.The thermal time constant and the steady temperature rise are basically the same under different current conditions.The thermal time constant of the carbon plate is greater than that of the copper wire,and the steady state temperature rise of the carbon plate is higher at the same working conditions.The temperature rise of a slide plate is accompanied by periodic small peaks,and the temperature at the edge is higher than that in the middle.The temperature in the contact zone of the skateboard is the highest.In front of the relative motion of the contact zone,the temperature gradient is large,and there is the "first temperature peak".While behind the relative motion,there is "high temperature trailing" phenomenon,and exist the "second temperature peak".The temperature change of copper conductor is gentle and the overall temperature is low.With the increase of the speed,the “peak distance” of “high temperature trailing” decreases gradually,and the“maximum temperature difference” increases gradually.While they all decrease first and then increase,with the increase of current.The results would provide certain references to further study on temperature characteristics of friction pairs,and in in reducing the wear of materials.