Modernization of electromechanical transmission for dump trucks based on long-term operation data

Abstract

In open pit mining, overburden and mineral haulage is carried out mostly by dump trucks. The number of high-capacity machines persistently grows. Such dump trucks mainly use electromechanical transmission systems. As a rule, dump trucks operate all day and all year round, with idle time for scheduled maintenance. The climatic service conditions assume variations in temperature, humidity and atmospheric pressure in wide ranges during a year, moreover, these physical quantities can fluctuate violently within a short time, for instance, within a day. The road conditions – road grade, hardness, roughness, length, altitude difference – differ greatly per open pit mines. Furthermore, air dustiness, including current-conducting coal- or metal-bearing dust should be taken into account. On the whole, these numerous and diverse factors are impossible to embrace in full at the stages of machine engineering and testing. Thus, during operation, it is necessary to accumulate and analyze the hand-on experience, and to improve all components of electromechanical transmission. This article gives data on four-year operation of BelAZ dump trucks with capacity of 90 and 240 t equipped with electromechanical transmission in open pit coal and ore mines. The traction electrical equipment faults are generalized, their causes are revealed, design modifications are described, as well as the processes of manufacturing and testing and the algorithm of diagnosis are reported. The low count of faults during operation and the high availability factor of the dump trucks equipped with electromechanical transmissions manufactured by RUSELPROM is reflective of the proficiency and competency of the machine engineering, design and testing. The modifications introduced into the electromechanical transmissions are mostly aimed at cost reduction and performance buildup, i.e. at competitive recovery of the product. The obtained results are used in engineering of traction electric equipment set for dump trucks of higher capacity (136, 180, 360 t).