The invention discloses a screw
drill transmission shaft
assembly which is used in oil and gas drilling and can reduce the
drill vibration, prolong the service life of the
drill and improve the mechanical drilling rate. The screw drill transmission shaft
assembly consists of a shell, an upper transmission shaft, an upper radial bearing static sleeve, an upper radial bearing dynamic sleeve, a loadbearing group, a vibration reducing device, a lower transmission shaft, a lower short section, a
central spindle and the like. The technical scheme is that: the upper transmission shaft is mounted inthe shell; the upper radial bearing static sleeve and the upper radial bearing dynamic sleeve are cooperatively mounted in an annular space formed by the shell and the upper transmission shaft; the
load bearing group is mounted at the lower ends of the upper radial bearing static sleeve and the upper radial bearing dynamic sleeve; the vibration reducing device is mounted at the lower end of the
load bearing group; when in work, a spline slot of the upper transmission shaft is matched with a spline of the lower transmission shaft; the lower short section is in threaded connection with the shell; and the
central spindle is in threaded connection with the upper transmission shaft. The screw drill transmission shaft
assembly disclosed by the invention does not increase the length of the lowerdrill, brings relatively little influence on the bottom drill combination, and can be applied to the angle building operation and curved borehole.