HYBRID DRILL BIT WITH HIGH RATIO BETWEEN DIAMETERS OF GUIDE STUD AND JOURNAL

摘要

FIELD: process engineering.SUBSTANCE: set of inventions relates to hybrid drill bits. Proposed hybrid drill bit comprises the part that follow: shank to be coupled with drilling string and supports of fixed cutters connected with said shank. Fixed cutting blades are rigidly connected with cutter supports at definite distance from said stem and comprise several cutting elements extending from the surfaces of blades. Legs of truncated-cone rolling cutters are attached to said shank and comprises axles with central line that have the journal arranged around said central and having a definite diameter. Guide stud is connected with the journal to extend in central line towards lengthwise axial line. Assemblies of rolling cutters attached to said legs nearby fixed cutting blades to run on said journal and guide stud relative to said shank around central line. Note also that said assemblies comprise cutting elements spaced from their surface. Ratio of guide stud diameter to journal diameter is equal to, greater than 0.58 and smaller than 1.0.EFFECT: higher permissible load at hybrid drill bit.11 cl, 6 dwg