SEALING OF SUPPORT OF ROLLING CUTTER BIT Russian patent published in 1997 - IPC

FIELD: bore-hole drilling equipment. SUBSTANCE: sealing of rolling cutter bit support has flexible ring interacting with end face of lug thrust shoulder. Ring is seated at interference fit in space formed by bore in rolling cutter and rigid bush installed with radial clearances relative to journal and rolling cutter, and with axial clearance relative to end face of bearing support. Flexible ring is installed at interference fit of 0.08 and main axial interference of up to 0.3 of its cross-section diameter in space narrowed due to double-stage boring in rolling cutter with shoulder between steps in the form of chamfer at angle of 35-55 deg. and at relation of width of space against first and second stages of boring from 0.5 to 0.8. Edge of lug shoulder adjacent to flexible ring is round at r which is equal to r = (10-14) S², where S - radial clearance between thrust shoulder of lug and rolling cutter. Outer surface of bush is provided with shoulders of height equal to interference radial fit of flexible ring. Shoulders embrace ring with no clearance at radial interference fit. Shoulders have flange which separates space where flexible ring is seated from support space. Length of cylindrical surface of bush is based on equality of cross-section area of flexible ring of nominal diameter minus allowance for its manufacture and that of same ring in working state provided it touches end surface of flange. EFFECT: high efficiency. 5 dwg