| 摘要 |
An improved journal bearing for rotary cone type mining or oilfield rock bits is disclosed. Such rock bits typically have several cutters each rotatably mounted on a cantilevered bearing pin. The cutter and respective bearing have complementary journal bearing surfaces. A retainer is provided at one end at the bearing surfaces for keeping the cutter on the bearing pin and a seal is provided at the opposite end. In addition to the usual axial thrust surface located towards the radially inner end of the bearing pin, one or more secondary axial thrust surfaces are provided in one embodiment of the invention. Alternatively, at least one series of grooves or other axial lubricant flow restrictor is provided at the complementary bearing surfaces. The invention greatly improves the load carrying capacity of the bearing.
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