公开(公告)号：WO2015023541A4

公开(公告)日：2015-02-19

申请号：PCT/US2014/050379

申请日：2014-08-08

Applicant: NATIONAL OILWELL VARCO, L.P.

Inventor： PHEASEY, Frederick William ,  CLEMENTS, Jeremy S.

IPC: F16D3/221 ,  F16D3/223 ,  E21B7/06

Abstract: An embodiment of a method for drilling a borehole into an earthen formation, the method including contacting a first end housing at a first axial position with a first drive key, wherein the first end housing has a central axis, a first end, a second end opposite the first end, and a first receptacle extending axially from the first end, and wherein the first drive key is disposed within the first receptacle in the first end housing and radially disposed between the first end housing and a driveshaft. In addition, the method includes transferring torque between the first end housing and the driveshaft via the first ball during. Further, the method includes, contacting the first end housing at a second axial position with the first drive key or a second drive key after (b), wherein the second axial position is axially spaced from the first axial position.