| 摘要 |
A drill string section for directional drilling is described, comprising an outer casing which encases an adjustment mechanism for adjusting drilling direction and angular deflection during drilling. The adjustment mechanism comprises an outer shaft that is rotatably arranged relative to the outer casing and is configured with an axial eccentric first bore having a first bore axis that is parallel to the centre axis. The adjustment mechanism further comprises an inner shaft that is rotatably arranged in the first bore and is configured with an axial, eccentric second bore for passage of a drive shaft for a drill bit. The adjustment mechanism further comprises an outer rotational mechanism for reciprocal rotation of the outer casing and the outer shaft, and for locking against the reciprocal rotary motion between the outer casing and the outer shaft, and an inner rotational mechanism for reciprocal rotation of the outer shaft and the inner shaft, and for locking against reciprocal rotary motion between the outer shaft and the inner shaft. |
