METHOD AND DEVICE FOR CREATING AXIAL THRUST ON BIT Russian patent published in 1999 - IPC

FIELD: bore-hole drilling machinery and equipment. SUBSTANCE: this relates to bore-hole drilling by using bottom-hole motors. Device incorporates drilling string. Connected to drilling string by means of adapters is hydraulic bottom-hole motor with drilling bit. Installed in adapter between drilling string and bottom-hole motor are following components: axial through-flow sliding support with thrust bearing and thrust journal, body of sliding support, resilient member, bush, cross-member with valve seat and valve disk which is rigidly connected with rod and body, adjusting rings, seals for cross-member. Holes intended for flowing of flushing liquid are provided in body, in bush, and in cross-member respectively. Method for creating axial thrust on drilling bit implies generation of additional axial force in valve of device, transmission of this additional axial force through resilient member, transmission part of force from drilling string to upper end of bottom-hole motor shaft and further to drilling bit, reduction of friction force occurred between drilling string and bore-hole walls by constant transmission of axial vibrations of drilling bit to drilling string from upper end of bottom-hole motor shaft, adjustment of range of parameters of axial vibrations transmitted to drilling string. EFFECT: higher efficiency. 2 cl, 1 dwg