U-Joint With High Torque Capacity And Improved Thrust Bearing Capacity

摘要

An assembly, apparatus, and method relate to a downhole motor drive shaft assembly drilling a subterranean wellbore. The assembly includes a drive shaft having a longitudinal rotational axis, a plurality of drive key sockets, an end housing having a longitudinal rotational axis, a plurality of circumferentially spaced axial keyways, and a concave spherical thrust bearing surface, and a drive key operatively connecting each drive key socket with a respective axial keyway for transferring torque from the drive shaft to the end housing. The drive key includes a substantially planar drive face slidably engaging the axial keyway, and a radiused, cylindrical back portion rotatably engaging the drive key socket, the substantially planar drive face and radiused, cylindrical back portion forming a nominal half-circle.

主权项

1. A downhole motor drive shaft assembly comprising:
a drive shaft having a first end, a second end, a longitudinal rotational axis, and a thrust insert socket located proximate one of the first end and the second end; an end housing having a longitudinal rotational axis and a concave spherical thrust bearing surface; a thrust bearing insert disposed within the thrust insert socket and a convex spherical surface in mating engagement with the concave spherical thrust bearing surface of the end housing; and a mechanism for transferring torque from the drive shaft to the end housing, the mechanism for transferring torque configured to be operationally effective irrespective of any relative angular offset between the rotational axes of the drive shaft and the end housing over a selected angular range; the torque transferring mechanism comprising a plurality of drive keys with a planar front face and a cylindrical back face, the two faces forming a nominal half-circle; wherein the thrust bearing insert comprises a material selected from the group consisting of a copper-nickel-tin alloy, an iron-chromium-nickel-manganese-silicon alloy, a copper-beryllium alloy, a cobalt-chromium-tungsten-carbon alloy, a copper-chromium-molybdenum alloy, a copper-chromium-nickel-molybdenum-iron-tungsten alloy, and a nickel-beryllium alloy.