| 摘要 |
FLOATING SEAL FOR DRILL BITS A rolling cone cutter earth boring bit is provided with a floating seal for sealing the bearings of the bit from the abrasive materials in the borehole and retaining lubricant within the bearing area. At least one cantilevered bearing pin extends from the arm of the bit. A cutter receiving surface is located on the arm. A first shallow annular groove is located in said cutter receiving surface. A rolling cone cutter is adapted to be rotatably mounted on the bearing pin with said rolling cone cutter having a cone mouth. A second shallow annular groove is located within said cone mouth. Bearing and cutter retaining means are located between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing pin between the cutter receiving surface and the rolling cone cutter. The first seal unit includes a first annular rigid ring positioned around the bearing pin and a first resilient ring located in the first shallow annular groove between the first annular rigid ring and the cutter receiving surface. A second seal unit is positioned around the bearing pin and located within the cone mouth. The second seal unit includes a second annular rigid ring positioned around the bearing pin within the cone mouth and a second resilient ring located in the second shallow annular groove between the second annular rigid ring and the cone mouth. The first and second seal units cooperate when the rolling cone cutter is mounted on the bearing pin so that the first and second resilient rings urge the first and second annular rigid rings into sliding contact as the cone cutter rotates about the bearing pin. -1a- |
