Patent ID: 9404527
Filing Date: 2016-08-02
CPC Classification: E21B,F16C,F16D

Claim Text:
1. A driveshaft assembly for a downhole motor, the driveshaft assembly comprising: a driveshaft having a longitudinal axis, a first end, and a second end opposite the first end; wherein the first end of the driveshaft includes a first connection lug extending circumferentially from a first end to a second end, a second connection lug extending circumferentially from a first end to a second end, and a first convex spherical bearing surface configured to transfer axial thrust loads; wherein the spherical bearing surface has a center of curvature disposed along the longitudinal axis; wherein the first connection lug includes a first recess at the first end of the first connection lug, wherein the first recess comprises a concave cylindrical surface concentrically disposed about a first pivot axis oriented orthogonal to the longitudinal axis and intersecting the center of curvature of the spherical bearing surface; wherein the second connection lug includes a second recess at the first end of the second connection lug, wherein the second recess comprises a concave cylindrical surface concentrically disposed about the first pivot axis; a first torque transfer key disposed within the first recess, wherein the first torque transfer key includes a convex cylindrical surface concentrically disposed about the first pivot axis and a planar surface, wherein the convex cylindrical surface of the first torque transfer key is configured to slidingly engage the concave cylindrical surface of the first recess and to rotate about the first pivot axis relative to the driveshaft; a second torque transfer key disposed within the second recess, wherein the first torque transfer key includes a convex cylindrical surface concentrically disposed about the first pivot axis and a planar surface, wherein the convex cylindrical surface of the second torque transfer key is configured to slidingly engage the concave cylindrical surface of the second recess and to rotate about the first pivot axis relative to the driveshaft; and a first end housing having a central axis, a first end, a second end opposite the first end, and a receptacle extending axially from the first end, wherein the first end of the driveshaft is disposed within the receptacle; wherein the first pivot axis intersects each of the first torque transfer key and the second torque transfer key; and wherein the driveshaft is configured to pivot about the first pivot axis relative to the first end housing while each torque transfer key transfers torque between the driveshaft and the first end housing.