| 摘要 |
A hydraulic rock drill having a hydraulic drill drive motor, a hydraulic feed motor, and a hydraulic impact unit and associated pumps for supplying hydraulic fluid under pressure and provided with an automatic control system including a valve controlling the flow to the impact unit under the dependence of the pressure in the rotation motor circuit such as to reduce the power of the impact unit when the pressure in the drive motor circuit exceeds a permissible pressure and vice versa. Additionally, the hydraulic system preferably includes an additional flow control valve such as to decrease the feed power when the impact power increases. |
