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US 3,944,306 AGranted
Rock bit bearing seal
AssigneeSmith International, Inc.
InventorWilliam J. Neilson
Life of this patent
Estimating the term…
Abstract
A bearing seal for a rock bit, including a non-elastic annular core member and inner and outer flexible sealing rings each securely bonded to the core member throughout substantially its entire circumference, the core member providing dimensional stability for the sealing rings and hence extending the useful life of the bearing seal despite the elevated temperature and pressure levels to which it is subjected.
Claims22
An earth boring tool comprising:
- a. a bit body having at least one journal leg thereon;
- b. a rotary cutter rotatably mounted upon said journal leg;
- said journal leg having surface portions providing the radially inward surface and the axially outward surface of a seal gland, said cutter having surfaces providing the radially outward surface and the axially inward surface of the seal gland;
- and
- c. an annular seal disposed within said seal gland, said annular seal including
- 1. an annular solid circumferentially continuous metallic core,
- 2. an inner sealing ring portion of flexible material having elastomeric characteristics and being bonded to the radially inward side of said metallic core throughout substantially the entire circumference thereof, said inner ring portion engaging said radially inward surface of the seal gland, and
- 3. an outer sealing ring portion of flexible material having elastomeric characteristics and being bonded to the radially outward surface of said metallic core throughout substantially the entire circumference thereof and engaging said radially outward surface of the seal gland;
- said inner and outer sealing ring portions being of substantially the same corss-sectional area and having substantially the same exposed surface in moving sealing engagement with respectively adjacent surface portions of the seal gland,
- said metallic core serving to maintain the dimensional stability of both said inner and said outer sealing ring portions despite high levels of temperature and pressure applied to both the interior and exterior sides of said seal.
7 more elements
In a rock bit having a bit body with at least one journal leg, a seal between the journal leg and the rotary cutter, said seal comprising:
- an annular metallic core;
- inner and outer sealing ring portions of flexible material having elastomeric characteristics;
- said sealing ring portions being disposed in opposite sides of said core, said inner ring portion having an annular engagement surface for a corresponding portion of the journal leg and said outer ring portion having an annular engagement surface for a corresponding portion of the cutter;
- and
- each of said sealing ring portions being bonded to said core throughout substantially the entire circumference thereof, whereby said core maintains the dimensional stability of said sealing ring portions despite high levels of temperature and pressure to which said seal is subjected, said engagement surface for the journal leg having an initial diameter greater than the diameter of the corresponding portion of the journal leg and said engagement surface for the cutter having a diameter greater than the diameter of the corresponding portion of the cutter whereby to compress said sealing ring portions between the journal leg and the cutter and in a direction transverse to the circumferential center line of said core.
2 more elements
Dependencies are inferred from the claim text.