| 释义 |
rotary drill rotary drill[′rōd·ə·rē ′dril] (mechanical engineering) Any of various drill machines that rotate a rigid, tubular string of rods to which is attached a rock cutting bit, such as an oil well drilling apparatus. rotary drillA machine for opening holes in rock or earth by means of a cutting bit at the end of a metal shank; usually turned by a hydraulically or pneumatically driven motor. |