دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a rotating machine housed primarily inside a rectangular steel box with an opening in the middle for the kelly and the drill pipe that creates and transfers the turning motion for rotary drilling;parts of the assembly include the base, rotary table, master bushing, driveshaft assembly, drawworks sprockets, driveshaft sprockets, and locking devices.