Study On Wheel-rail Friction Simulation Test System Based On Differential

Wheel-rail adhesion is a special phenomenon of wheel-rail rolling friction.The bench test to study the wheel-rail adhesion-creep dynamic characteristics is an effective method.The test results of the small-scale test rig deviate greatly from the line results.The full-scale test rig is closer to the true state of the line.However,the conventional full-scale test rig usually uses mechanical open-loop method,which requires a lot of equipment investment and high energy consumption;therefore,the research is oriented to wheel-rail adhesion-creep.The economical simulation test bench for sliding characteristic test is of great significance.In this thesis,adopts the mechanical sealing principle and the loading method of the active differential,and the related research work on the wheel-rail friction simulation test system based on the differential is as follows:First of all,analyze and evaluate the wheel-rail friction simulation test rigs at home and abroad from the aspects of mechanical sealing,normal force loading,slip speed stability,detection accuracy,etc.,and clarify the composition of the wheel-rail friction simulation test system.Study the application of mechanical enclosed energy-saving test technology in gear test and material test,and form the preliminary concept of wheel-rail friction simulation test system.Secondly,analyze wheel-rail adhesion and creep phenomena,study the test methods and results of adhesion-creep characteristics tests,and determine the conceptual design of the stick-slip test system loaded with planetary differentials by studying the principle of mechanical sealing and its application.Adopting the Hertz simulation criteria,the MATLAB program for parameter calculation of the simulation test bench is written,the key parameters of the test bench are calculated and checked,and the design requirements of the test system are determined.Calculate and simulate key data such as normal force,torque,contact spot size,stress distribution and other key data in the laboratory under the conditions of 840(1:4),1050(1:5)and 1260 mm(1:6).And provides basic data for friction simulation test system.Then,according to the measurement and control requirements of the wheel-rail adhesioncreep characteristic test,design the mechanical structure,complete the selection of standard parts and the design of non-standard parts,analyze the system errors,and check the strength and stiffness of the main load-bearing parts.According to the control requirements of the adhesion-creep characteristic test of the test system,complete the hardware selection and design of the servo control system;according to the test and measurement requirements,use Lab VIEW and PXI-6123 acquisition card to complete the data acquisition and processing system design.Finally,determine the method and test procedure of the wheel-rail adhesion-creep test.Then the data acquisition and processing system of the wheel-rail friction simulation test rig was debugged,and the simulation test of wheel-rail adhesion-creep characteristic curve was carried out to verify the functions of the data acquisition and processing system.The above research work shows that: the wheel-rail friction simulation test system based on the differential has good feasibility and lays the foundation for the establishment of a fullscale test rig.