Design and technological aspects of functionally oriented technology of manufacturing the three-cone drill bits

Abstract

The quality and efficiency of the drilling process significantly depend on the design parameters and operational peculiarities of the drill bit cutter. The present paper is focused on developing the functionally oriented technology of manufacturing the three-cone drill bits. The research methodology involves the theoretical and experimental studies dedicated to analysing the main reasons for the loss of the cutters working capacity, and the technological factors that affect the strength and durability of the “tooth – cutter” press connection. The major scientific novelty consists in defining the relationships between the design parameters of the cutters, their kinematics, dynamics, and operational conditions. It has been established that the destruction of the rock by the three-cone drill bits is carried out by applying successive impacts of the tipped hard-alloyed teeth upon the rock. The rolling of the cutters (bits) along a face (stope) exerts a dynamic effect due to the alternate change of the contact of the teeth with the rock, and the axial load on the bit ensures that the striking part of the teeth is pressed into the rock. The character of wear and destruction of the tipped teeth also has an important influence. During the drilling process, the rock-destructing parts (teeth), as well as the working areas of the cutters, undergo intensive wear and failure. This leads to a significant decrease in the quality of the rock destruction process and a reduction in the drilling efficiency. The obtained results have a significant practical value and can be effectively used by designers, technologists and researchers while implementing the energy-efficient drilling technologies.