Drive vibrational drilling

摘要

A rotary drive assembly for a drill string includes a spindle A, M to be connected to the shaft of the drill string, a coupling connecting the spindle to an apparatus to axially vibrate the spindle, and an array of guide pins F axially aligned with and attached to the spindle. A carriage D including sleeves E which slide on the guide pins, a driven gear C attached to the sleeves and a geared drive B for driving the driven gear is arranged to rotate the spindle by the rotation of the driven gear acting via the sleeves on the pins whilst being somewhat isolated from the axial vibration that is imparted to the spindle.