Author 1:
Name & Surname: Klishin V. I.
Company: Institute of Coal, Siberian Branch, Russian Academy of Sciences (Kemerovo, Russia)
Work Position: Head of laboratory
Scientific Degree: Corresponding member of the Russian Academy of Sciences

Author 2:
Name & Surname: Nikitenko S. M.
Company: Institute of Coal, Siberian Branch, Russian Academy of Sciences (Kemerovo, Russia)
Work Position: Principal Researcher
Scientific Degree: Doctor of Economical Sciences
Contacts: e-mail: nsm.nis@mail.ru

Author 3:
Name & Surname: Gerike B. L.
Company: Institute of Coal, Siberian Branch, Russian Academy of Sciences (Kemerovo, Russia)
Work Position: Senior Researcher
Scientific Degree: Professor, Doctor of Engineering Sciences

Author 4:
Name & Surname: Krestovozdvizhensky P. D.
Company: Mining Tool Company (Novokuznetsk, Russia)
Work Position: Head of Engineering Department
Scientific Degree: Candidate of Engineering Sciences

The article is concerned with improvement of strength and durability of rotary cutters capable of destructing medium-hard rocks at the minimized energy input and high efficiency. Analysis of stress state in various shape hard-alloy reinforcing elements (cylindrical, “mushroom,” with different Gaussian curvature) was performed with ANSYS finite element models using SOLID95. Additionally, various shapes of generatrix of cones of a cutter were analyzed: concave (for cutting weak coal and for minimized coal overgrinding), linear (coal and rock cutting) and convex (hard coal and medium-hard mineral cutting). The study of strength of reinforcing elements involved cross-bending modeling as hard alloys are weak in bending. Stress distribution inside the hard-allow reinforcing elements showed that the ellipse-shaped element is stronger as the maximum stresses in this case are two orders of magnitude lower than the stresses in the cylindrical element with a cone. Moreover, the strength balance is ensured in the design of the head part of the cutter with the ellipse-shaped reinforcing element. Based on the modeling results, it was recommended to make reinforcing elements for cutters in the form of indenter–ellipsoids, having no stress concentrators and destructing rocks by a large cleavage. The tests of the trial models of tangential rotary cutters with conical generatrix, reinforced with hardalloy elements with the cutting edge formed as the ellipsoid of rotation in the Kuzbass mines confirmed the modeling results.
The study was conducted with financial support from the RF Ministry of Education and Science, within the framework of the federal target program “Research&Development in the Priority Trends of the Science-and-Technology Complex of Russia for 2014–2020” on the topic of “Development of Experimental Designs of a Combination Tool Using Superhard Composite Materials for Efficient Destruction of Rocks” (Agreement No. 14.607.21.0028 as of 06.06.2014).
This work was carried out within the State Contract No. 2014/97.

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