摘要 |
The invention relates to downhole motors for rotating drill bits. The downhole motors may comprise stators, turbines or the like. The drilling motor may comprise a drilling apparatus comprising a drill bit connected to a rotor rotatably housed within a stator (or a turbine rotor in a housing), the rotor comprising at least one magnetic field source or magnetic field detector, and the stator comprising at least one magnetic field source if the rotor comprises a magnetic field detector or comprising at least one magnetic field detector if the rotor comprises a magnetic field source, thereby allowing the rotation speed of the rotor relative to the stator to be measured. |