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US 9,957,756 B2Granted
Roller cone drill bit assembly with varying radius bearing surfaces
AssigneeHalliburton Energy Services, Inc.
InventorQin Shiwei
Life of this patent
Estimating the term…
Abstract
A roller cone drill bit assembly with a bearing shaft having an outer bearing surface and defining a rotational axis. The outer bearing surface includes a necked portion having a varying radius with respect to the rotational axis. A roller cone is coupled about the bearing shaft and includes an outer cutting structure and an inner bearing surface. The inner bearing surface includes a necked portion proximate to and closely conforming to the necked portion of the outer bearing surface.
Claims19
A drill bit assembly, comprising:
- a bearing shaft having an outer bearing surface and defining a rotational axis, the outer bearing surface including a necked portion having a varying radius with respect to the rotational axis;
- and
- a roller cone coupled about the bearing shaft and including an outer cutting structure and an inner bearing surface, the inner bearing surface including a necked portion proximate to and closely conforming to the necked portion of the outer bearing surface,
- wherein the necked portion of the outer bearing surface has a first radius of curvature in a plane through the rotational axis and the necked portion of the inner bearing surface has a second radius of curvature in a plane through the rotational axis, wherein the first radius of curvature differs from the second radius of curvature.
1 more element
A drill system comprising:
- a drill string provided in a wellbore, the drill string having a drill bit assembly provided on an end,
- the drill bit assembly having:
- a bearing shaft having an outer bearing surface and defining a rotational axis, the outer bearing surface including a necked portion having a varying radius with respect to the rotational axis;
- and
- a roller cone coupled about the bearing shaft and including an outer cutting structure and an inner bearing surface, the inner bearing surface including a necked portion proximate to and closely conforming to the necked portion of the outer bearing surface,
- wherein the necked portion of the outer bearing surface has a first radius of curvature in a plane through the rotational axis and the necked portion of the inner bearing surface has a second radius of curvature in a plane through the rotational axis, wherein the first radius of curvature differs from the second radius of curvature.
3 more elements
Dependencies are inferred from the claim text.