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U.S. Department of Energy
Office of Scientific and Technical Information

Hydrodynamic lubricant seal for drill bits

Patent ·
OSTI ID:5303089
This patent describes a rotary cone type drill bit having a cone support structure incorporating a body structure forming a liquid lubricant supply and a plurality of bit support legs, each leg having an axle supporting a roller cone cutter element in rotatable relation thereon. The improvement consists of: (a) a seal chamber being defined cooperatively by the roller cone cutter element and the cone support structure and being formed in part by a circular relatively rotatably movable sealing surface; (b) a resilient circular hydrodynamic sealing element disposed about the axle and within the seal chamber and maintaining a seal between the roller cone cutter element and the cone support structure and forming a sealed partition establishing a drilling fluid interface and a lubricant interface, the circular sealing element establishing a sealing interface with the circular rotatably moveable sealing surface; (c) the lubricant interface being of a configuration acting cooperatively with the liquid lubricant to hydrodynamically induce lubricant wedging causing controlled unidirectional hydrodynamic pumping of lubricant from the lubricant interface through the sealing interface to the drilling fluid interface responsive to rotation of the roller cone cutter element about the axle for lubrication at the sealing interface and for lubricant flushing of solid particulates from the sealing surface.
Assignee:
NOV; EDB-86-172962; NOV-85-024045
Patent Number(s):
US 4610319
OSTI ID:
5303089
Country of Publication:
United States
Language:
English