Self-lubricating elastomeric seal with polarized graphite
First Claim
1. A journal seal for use in a rotary cone rock bit comprising:
- a flexible and resilient seal body formed from an elastomeric material selected from materials consisting of highly-saturated nitrile elastomers, nitrile-butadiene rubber, highly-saturated nitrile-butadiene rubber, and mixtures thereof; and
a seal dynamic surface along cone surface area of the seal body, and a seal static surface along another surface area of the seal body, each formed from an elastomeric material, wherein the elastomeric material further comprises polarized graphite at least at the seal dynamic surface.
1 Assignment
0 Petitions
Accused Products
Abstract
O-ring seals for rock bit bearings comprise a body formed from an elastomeric material having a lubricant additive in at least the dynamic seal surface to reduce the coefficient of friction and stick-slip amplitude at O-ring seal surfaces. The lubricant additive comprises polarized graphite. O-ring seals made from elastomeric compositions comprise in the range of from about 50 to 99 percent by volume elastomeric material, and in the range of from about 1 to 50 percent by volume of the polarized graphite based on the total volume of the composition. Preferably, the polarized graphite is in the range of from 7 to 25 percent by volume. As the O-ring seal experiences wear from adjacent metal surfaces, flakes of polarized graphite are released from the O-ring seal and adhere to the adjacent metal surfaces and form a lubricating film.
-
Citations
26 Claims
-
1. A journal seal for use in a rotary cone rock bit comprising:
-
a flexible and resilient seal body formed from an elastomeric material selected from materials consisting of highly-saturated nitrile elastomers, nitrile-butadiene rubber, highly-saturated nitrile-butadiene rubber, and mixtures thereof; and
a seal dynamic surface along cone surface area of the seal body, and a seal static surface along another surface area of the seal body, each formed from an elastomeric material, wherein the elastomeric material further comprises polarized graphite at least at the seal dynamic surface. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A rotary cone rock bit for drilling subterranean formations comprising;
-
a bit body including a plurality of journal pins each extending from a leg portion of the bit and having a bearing surface;
a cutter cone rotatably mounted on each journal pin and including a bearing surface;
a grease adjacent the bearing surfaces; and
a dynamic annular seal for retaining the grease between the bearing surfaces comprising;
a body portion and a surface portion both being flexible and resilient, and each being formed from an elastomeric composition selected from materials consisting of highly-saturated nitrile elastomers, nitrile-butadiene rubber, highly-saturated nitrile-butadiene rubber, and mixtures thereof, wherein the elastomeric composition at least adjacent a surface portion additionally comprises polarized graphite. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A rotary cone rock bit for drilling subterranean formations comprising:
-
a bit body including a plurality of journal pins each extending from a leg portion of the bit and having a bearing surface;
a cutter cone rotatably mounted on each journal pin and including a bearing surface;
a pressure-compensated grease reservoir in communication with such bearing surfaces;
a grease in the grease reservoir and adjacent the bearing surfaces; and
a dynamic O-ring seal for retaining the grease between the bearing surfaces comprising;
a resilient and flexible elastomeric body having a static sealing surface along a first body portion and a dynamic sealing surface along a second body portion, the elastomeric composition further comprising polarized graphite uniformly distributed in at least the dynamic sealing surface. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
-
Specification