Effect of inset teeth surface shape of the rock bit cutting structure on the energy intensity of rock failure

Abstract

This paper deals with the study of the problem relating to the efficiency of the rock bit cutting structure work in
the course of rock failure, which is associated with the rolling cutter teeth design peculiarities improvement as well
as the proper placement of the hard alloy – relit both on the surface and within the volume. This paper gives the
description of the study obtained on the rock bit cutting structure durability in the form of milled investigated teeth
while modeling their wear resistance conditions that are near to the real ones. Studied here is the effect of the
working components of the rock bit cutting structure tools design peculiarities and their shape effect in the course of their wear on the rock failure, namely, on the teeth penetration depth into the rock. The degree of the initial rock
failure characteristic of the patterns investigated was determined by the constant ability of their penetration depth
into the elastic medium with the set physical and mechanical properties with the permanent axial loading by means
of a specially developed device at the set period during their wear characteristics study. The evaluation of the effect
of the hard alloy varying layout on the study patterns surfaces as to their wear value of the study patterns using the
methods of linear, weight and volumetric analysis. The study data analysis shows that the efficient hard alloy
placement on the study patterns surfaces and properly the rock bit cutting structure enables to control the study
patterns of the inset teeth durability against impact and friction wear and to keep constant the specific pressure
transferred to the bottomhole in the course of the rock failure. It has been established that the hard alloy placement
on the inset surfaces of the rock bit cutting structure effect its wear characteristics while drilling the rock of soft and
medium hardness. The data obtained in the course of this study shows the possibility of carrying out the further investigation
of the rock failure processes at the bottomhole with the view of searching for the advice as to the relit
placement on the inset rock bit cutting structure working surfaces for the purpose of determining the optimum
weight share of relit placement. It has been confirmed that one of the efficient indices which can be characteristic
both of the rick failure processes and those of possible wear and designing the rock failure tools to be the specific
loading value transferred to the bottomhole while drilling.