| 摘要 |
<p>A top drive system is provided. In one embodiment, a top drive (28) includes a drive stem (46, 86) and a load nut (62) with mating threaded surfaces (64, 94) that enable the drive stem to be threaded through the load nut and to support weight of a connected drill string (16) via the load nut. One or both of the mating threaded surfaces may have a threadform with one or more undercut thread roots (104, 124). Additionally, a portion of the mating threaded surfaces, such as thread roots (124) of the drive stem, can be shot-peened. Additional systems, devices, and methods are also disclosed.</p> |
