摘要 |
A blast-hole drilling rig includes a carriage, a mast disposed on the carriage, and a rotary head mounted on the mast for up-and-down movement. The rotary head includes: a housing forming an internal chamber, a hydraulically driven motor, and a rotation transmission mechanism disposed in the chamber. The rotation transmission mechanism includes a gear system having a high-speed power input section operably connected to the motor, and a low-speed power output section adapted for connection to a drill pipe. The rotation transmission mechanism includes an anti-vibrational inertial body forming part of the high-speed power input section for storing rotational energy to even-out rotary speed variations and resist the generation of vibrations during operation. The inertial body includes a downwardly open recess in which the motor casing extends, wherein the motor projects downwardly past a bottom wall of the housing.
|