| 摘要 |
A rock drill bit is provided with a fluid seal for the cutter bearing. The bit has a bit segment on which an annular outer bearing race is removably mounted. The bearing race carries a rotary cutter with a hub projecting into the center of the race and an inside surface overlying the outer surface of the race to provide a narrow gap. The gap and thus the bearing is sealed by a pressurized fluid flowing through ducts in the bit, into the gap and out of its open end to flush away any fine cuttings. |
