Study On The Front Axle Auxiliary Drive System For The Off-road Wide-body Dump Truck

Off-road wide-body dump truck is a kind of non-road heavy-duty dump truck for the purpose of ore transportation and rock earth transportation in the open air.It has the following characteristics,such as large scale,large load capacity,poor working environment and complicated road conditions.In the actual operation process,there is often insufficient climbing performance,tire slippery,serious friction heat of downhill braking and so on,due to slippery road,steep slope and other reasons.Based on the current problem of off-road wide-body dump truck,this paper presents a single pump single motor front axle auxiliary drive system,(1)This paper analyzes the advantages and disadvantages of several front axle auxiliary drive systems,and proposes the single pump single motor auxiliary drive scheme.in which the hydraulic pump uses the pump of lift mechanism to reduce the addition of new components.So this system is very simple,economical and practical.Install a front axle auxiliary drive system on the basis of the original dump truck,we can achieve three functions: In the climbing conditions,the dump truck is driven from a rear axle to a double bridge drive to improve the utilization of attached weight and increase climbing ability;,When the rear wheels fall into the pit after unloading,we can use the front axle independently to escape;In the downhill braking,we can use the reaction force of brake to store brake energy in the accumulator,not only to achieve hydraulic auxiliary brake,but also to absorb energy and reduce friction heat.(2)According to the original truck parameters and the requirements of driving conditions,hydraulic components of the system is calculated and selected.Aiming at the different working conditions of off-road wide-body dump truck,the method of switching the different working modes after the installation of the front axle auxiliary drive system and the solution of the synchronous problems between the front and rear wheels are proposed.According to the calculation formula of the theoretical efficiency of hydraulic pump and motor,the curve of efficiency with the working pressure and operating speed is obtained.According to Boer’s law,the energy recovery process of the accumulator is obtained by hydraulic auxiliary braking.(3)Through the analysis of kinematics and dynamics,the traction characteristic curve of the dump truck under the operation condition of no-load and full-load is obtained.(4)The AMESim simulation software is used to model and simulate the front axle auxiliary drive system.The dynamic response performance of the front axle auxiliary drive system is obtained,the energy recovery and reuse performance of accumulator is obtained and the improvement of the traction performance is verified.