Rotationsgeschwindigkeitsgeber fuer Bohrturbinen

摘要

1326329 Tachometers SOC NATIONALE DES PETROLES D'AQUITAINE 11 May 1972 [14 May 1971] 22168/72 Heading G1N The speed of rotation of the shaft 4 Fig.2 of a turbine at the bottom of a drilling string is sensed by a reed switch 20 supported by a tube 22 near a magnet 25 rotating with the turbine shaft. The switch produces a train of pulses which are transmitted to the surface and its frequency measured. The bent tube 22 is attached to a straight tube 21 by a centering component 19, and the assembly is supported by an upper webbed flange 17. In another embodiment Fig. 3 (not shown) the transducer comprises a coil on a fixed magnet and a rotating metal pin which, once per revolution, produces a flux change and a voltage pulse in the coil.