| 摘要 |
A drill rod for a drill string has a thread 16,18 at each end and is connected to an adjacent rod by a sleeve 14. The diameter of the outer surface of the rod is greater than or equal to 65 mm and is at least twice the diameter of an internal bore 27. The threads on the rod and sleeve are configured to reduce stress concentrations and provide sacrificial wear on the sleeve. The thread has a single start with a part circular root 42 with linear flanks 44 extending tangentially from the root. Each of the threads has a wear volume 48 between adjacent flanks 44 with the wear volume on the sleeve being less than that on the rod. |
