Improving the Labor Safety of Mining Dump Truck Drivers by Reducing the Risk of Failure of the Functional Units of the Traction Electric Drive under Operating Conditions

Abstract

The results are presented concerning the analysis of statistical data on failures of the functional units of traction electric drives of the mining dump trucks. It is established that the costs of failure recovery in the synchronous generator are higher than in a control cabinet and an asynchronous traction motor, and one of the causes of defects in the bearing assembly of the generator is the effect of self-supporting axial shock vibrations. And in addition to the effect of vibrations on the reliability of the synchronous generator, they are also the cause of the development of professional noise-vibration pathology, which in turn leads to a decrease in the efficiency of drivers of the dump trucks and to the adverse consequences on their body. It is revealed that such an impact on the generator is due to the fact that when moving, the dump truck overcomes large differences and slopes, which contributes to the appearance of electric drive trim levels. To determine the causes of axial shock vibrations, full-scale tests were carried out on 2 mining dump trucks during their operation at a coal mine in the Kemerovo region, it was revealed that the maximum vibration amplitudes are achieved in the range of 100–400 Hz at 1900 rpm and at a rated electrical load, and the overall vibration level across the spectrum was 18 m/s2. It is established that to solve the problem it is required to follow the following recommendations: obtain a shock mode on the isolated generator at the plant stand, record the conditions of its occurrence and the stability limits; block the axial movement of the bearing by installing radial or axial spacers, make sure that the shock mode does not occur; carry out periodic monitoring to measure vibrations in the functional units of the traction electric drive during operation. The presented recommendations will allow to increase the trouble-free operation time of the traction electric drive and improve the safety of mining dump truck drivers.