Reliability Analysis and Maintenance Scheduling of the Electrical System of Rotary Drilling Machines

This paper studied reliability of electrical system for electrical-hydraulic rotary drilling machines. Reliability is the most important characterization of repairable systems. Electrical systems have a vital role in any electrical-diesel or electrical-hydraulic machines. As any failure in electrical system finally leads to stopping the machine, research on the reliability of this system is essential. In this research reliability of electrical system of drilling machines in Sarcheshmeh copper mine in Iran had been modelled and analysed. There were four hydraulic-electric machines in this mine (named A, B, C and D), that all of them had been selected for data collection and analysis of failure. The results of statistical analysis showed that time between failures (TBF) data of this system follows the gamma distribution for machines A and C and weibull (3P) and exponential distributions for machines B and D, respectively. Also, the results showed that with considering 90 % for preventive maintenance (PM) interval, after the first maintenance the reliability of this system will be improved by 5.23, 7.22, 3.62 and 5.26 % respectively for machines A, B, C and D.