Efficiency of pneumatic perforators, durability and reliability of their work are largely determined by lubrication of the rubbing parts. The studies carried out at the Pnevmatika plant have shown that under conditions of high dynamic loads, sliding speeds of contacting surfaces and increased temperatures in the contacts, lubrication significantly affects the parameters of the perforator, especially the torque, as well as the rate and nature of wear of the main rubbing parts.

In recent years, oil shale production in the Soviet Union has increased significantly. The rate of development of the oil shale mining industry significantly exceeds the rate of development of the coal industry. In the directives of the XIX Congress of the CPSU on the fifth five-year plan for the development of the national economy of the USSR for 1951-1955 it is stated: “...to increase oil shale production by 2.3 times, especially in the Estonian SSR”. Such a rapid development of the oil shale industry is possible only on the basis of the highest technology. Oil shale mines are equipped with modern powerful machines and mechanisms. However, this technology is not used efficiently enough yet, which is explained mainly by insufficient study of the processes of mining machines operation in specific conditions of oil shale mines. There is a great number of researches on coal cutting, but there are absolutely no works on oil shale cutting. The material presented in this paper is based on experimental studies of notching in oil shale. The researches were carried out for several years at the mines of Leningradslanets and in the laboratories of the Leningrad Mining Institute. The experiments were carried out without self-recording instruments, only a set of small-sized electrical measuring devices was used, which slightly reduced the accuracy of readings (within 5-7%)