Method for calculating annual duration of maintenance and repairs of domestic and foreign excavators considering time in service

Introduction. Over the years of cooperation between foreign manufacturers and domestic operating enterprises, a significant amount of construction equipment has been supplied. In this regard, there is a need to develop and improve existing standards governing the methodology for calculating the operating modes of construction machines. Often, the use of indicators given in regulatory documents shows a significant discrepancy in comparison with the actual indicators obtained characterizing the annual operating modes of machines. The article presents a method for calculating the annual duration of technical maintenance and repairs (TM and R) using the example of single-bucket hydraulic excavators of domestic (EOD) and foreign production (EOFP). Methods and materials . The method is based on the obtained patterns of changes in operating time between failures, the duration of maintenance and repair of analogues of EOD and EOFP. Results. As the studies have shown, over the course of operation, the annual duration of maintenance and repair in the EOD increases by 1.73 times, and 1.13 times in the EOFP; the duration of a single maintenance and repair in the OED is 2 times, and 1.4 times in the EOFP; the average time between failures in the EOD is 1.65 times less than in the EOFP at the studied intervals. The indicator of the duration of the EOD in TO and P for 1 operating hours, based on the dependencies obtained, shows an excess of 4.25 times, and according to the regulatory source MDS 12-8.2007, it is 6.03 times higher than that of its foreign counterpart. Discussion and conclusions . As a result of the application of the proposed method, the annual fund of time costs associated with maintaining and restoring the working technical condition can be predicted not only for domestic, but also for foreign single-bucket hydraulic excavators, the accuracy of planning the work performed increases compared with existing standards, this enables to take into account the unevenly distributed annual downtime depending on the planned working time, this will have a positive effect on the planning of the use of equipment. The data obtained can be used for the EOFP of the 5-th standard-sized group as normative