Performability of electro-hydro-mechanical rotary head of drill rig in open pit mining: A case-study

reliability improvement of drill rig model SBSH-250MNA-32. The article describes the studies in the field of mining machines and the relevant engineering solutions. It is critical for Russia to preserve and replenish its mineral resources and mineral reserves to pursue social and economic advance. The priority growth of coal and gold production using the advanced open pit mining method can increase percentage of the latter in cumulative mineral mining by not less than 50%. Furthermore, it is necessary to cut down costs of production by 4–5%. The main and extremely labor consuming process in open pits in Russia is drilling which takes up to 40% of total mining cost [1–3]. The common method of drilling in rocks with the hardness factor of 6–20 on Proto-dyakonov’s scale in Russia is the roller-bit drilling [4–6]. This drilling processes is accom-panied with high dynamic loading imposed on the rotary-and-feed mechanism [7–9]. One of the ways of reducing dynamic loads in the roller-bit drill rigs is redesigning of the rotary-and-feed mechanism to possess higher safety and anti-vibration properties, simpler structure, as well as better performability and longevity [7, 8, 10–13]. This article describes and substantiates the design and operating principle of the electro-hydro-mechanical rotary head, its prototype testing, the research program and procedure, the instrumentation preparation, the research objective as well as the test data processing and analysis as a case-study of drill rig model SBSH-250MNA-32. three-level active rectifier, which ensure the standard quality power supply in longwall, are substantiated.