The invention relates to a downhole tool electromagnetic rotating speed control pup joint, and belongs to the technical field of
oil and natural gas exploitation drilling tools. The downhole tool electromagnetic rotating speed control pup joint comprises a shell, an
upper joint, a lower joint, a rotating shaft and a switching device. The rotating shaft is installed in the shell, magnets are symmetrically installed on the rotating shaft through support frames, a lower spline joint is installed on the position, on the outer side of a lower alignment bearing, of the rotating shaft in a threaded mode, the switching device is installed on the position, on the outer side of an upper alignment bearing, of the rotating shaft in an interference mode, and an upper spline joint is installed on the position, on the outer side of the switching device, of the rotating shaft in a threaded mode. According to the downhole tool electromagnetic rotating speed control pup joint, the structure is simple, the design is novel, the problems that an existing speed limiting ring cannot
well control the rotating speed of a tool, and once damping
grease in the speed limiting ring is used up, the speed limiting ring can lose
efficacy, and the speed reducing effect cannot be generated on the tool are solved, the pup joint can meet the requirement of a downhole sand-washing and well-flushing tool for the
rotational flow rotating speed so that the tool can reach the best working state under different working conditions, and the downhole tool electromagnetic rotating speed control pup joint has wide application prospects.