Characteristics Research On Full Hydraulic Steering System With Coaxial Flow Amplification

In recent years, with construction machinery constantly moving large-scaledevelopment, its steering system torque also will be gradually increased. Because the fullhydraulic steering system with coaxial flow amplification has advantages, which are largesteering torque, small size, light weight, steering sensitivity, it is more and more widelyused on the large construction machinery.This dissertation is found by the school-enterprise cooperation project” Dynamicssimulation of a large loader with load-sensing hydraulic steering system”. Based onAMESim simulation software, dynamic simulation model of the steering system is built,and the steering performance is analyzed under different conditions. Through the benchtest of steering system, simulation model is verified reasonable. Finally, aimed at thepressure phenomenon of steering system, steering system is optimized and designed usingMotion dynamics simulation software and AMESim simulation software. This dissertationhas been made the following research work:(1) Firstly, this dissertation introduces the work process of the full hydraulic steeringsystem with coaxial flow amplification, and respectively introduces working principle ofsteering system main components: priority valve and coaxial flow amplifying steering gear;Then this dissertation analyses the working principle by setting mathematical model forsteering system. Finally, it introduces the turning load of the steering system by analyzingtires-ground load characteristics, which lays theoretical basis for the simulation analysis.((2) Based on the actual structure and working principle of priority value and steeringgear, relying on AMESim simulation software, build their corresponding component-levelsimulation model; other hydraulic components of steering system build system-levelsimulation model. According to the actual conditions of steering system, set the inputsignal of the steering system, and analysis its turning performances. (3) According to the actual working condition of the steering system, design benchtest of steering system. In tests, under the conditions of different steering speed, differentengine speed and different steering load, the test of steering system has been carried on.Based on the test data, turning performance in different working conditions was analyzed.Finally, a comparative analysis of simulation and experiment is made, determining theaccuracy of the simulation.(4) The use of AMESim simulation software and Motion simulation software makeco-simulation analysis for steering system. Through simulation analysis found that there isa serious pressure pendulum phenomenon in steering system. Finally, based onco-simulation platform, coaxial flow amplification steering gear has been optimized toimprove, reducing the pressure pendulum phenomenon in steering system.