摘要 |
A drill head (4) for a rotation drilling rig (1), including: a rotation motor (M), a drill head spindle (7), and a gear change transmission (8) between the rotation motor and the drill head spindle, the gear change transmission (8) including an input shaft (9) connected to the rotation motor and an output shaft (10) connected to the drill head spindle. The input shaft (9) is co-axial with the output shaft (10), the input shaft (9) is permanently coupled to an intermediate shaft (12) over a first speed reduction gear couple (13), the gear change transmission (8) includes a clutch (14) being shiftable between a first position interconnecting the input and output shafts (9,10) for obtaining the same rotational speed for the input and output shafts, and a second position connecting the intermediate shaft (12) to the output shaft (10) over a second speed reduction gear couple (15). The invention also relates to a rig. |