Dyna-drill

OBS: Dénomination d'un moteur de fond volumétrique.
OBS: Dyna-drill [exposant MC] : Marque de commerce de Dyna-Drill.

OBS: A trade name for a downhole motor driven by drilling fluid that imparts rotary motion to a drilling bit connected to the tool, thus eliminating the need to turn the entire drill stem in order to make hole.
OBS: There are two types of turbodrill or down-hole mud motor: the turbine, of which there are about six successful types, and the Dynadrill, a Moyno pump operating in reverse, consisting of a spiral shaft contained within a rubber sleeve.
OBS: Electric tools, now out of production.