| 摘要 |
A drill pipe torque control device is driven via a flexible coupling from the downhole end of a torque control pump rotor so that the device input is driven at the same rotational speed as the drill pipe. A gearbox 14 with a step up ratio of 5:1 is used to drive an electrical generator 15 which is current loaded 17 from the output of a roll control processor to give a load torque as required to drive a control valve 9 which controls flow through a main orifice system. The gearbox may be a differential gearbox or epicyclic and used to drive a flap valve. |
