| 摘要 |
In order to compensate for variations in idle losses in the rotation motor (7) one establishes a relation between idle pressure and temperature for the rotation motor. This relation is stored in the memory in a control unit (21). During drilling the temperature of the liquid passing the rotation motor (7) is measured. This value and said relation are used to determine a reference pressure corresponding to the idle losses in the rotation motor. The drilling is then controlled by the difference between the measured pressure of the liquid supplied to the rotation motor during drilling and said reference pressure. |
