| 摘要 |
A hydraulic system for a drilling apparatus where torque is transmitted to drill pipe, a plurality of thrust cylinders move the torque transmitter back and forth along the drill pipe axis, and a hydraulic motor supplies torque to the torque transmitter, includes: a first drive pump for supplying hydraulic fluid to the motor; a first valve between the first drive pump and motor for selectively controlling the direction of fluid flowing to the motor; a second drive pump for selectively supplying fluid either to the thrust cylinders or motor; a second valve between the second drive pump, on one side, and the thrust cylinders and motor, on the other side, for selectively diverting fluid flow from the second pump either to the thrust cylinders or the motor; a third pump for supplying fluid to the thrust cylinders; a third valve connected between the second and third pumps, on one side, and the thrust cylinders, on the other side, for selectively controlling the direction of fluid flowing to the thrust cylinders; and a charge pump connected to the inlets of the first and second drive pumps for supplying fluid thereto at a positive pressure for overcoming pressure losses in the system. |
