Percussion drill assembly

摘要: A compressor piston divides a first compartment into two compression chambers, while hammer second drive each of the chambers being connected to respective one form closed fluid system wherein reciprocation causes cyclic and expansion in thus effect impacting with bit adapter drill bit. mud motor rotates shaft an oscillator which reciprocates piston. The can comprise roller elements engagement canted grooves shaft. While drilling drives then passes downwardly flush borehole, is isolated from system. slides axially, so that when not contact borehole bottom, move position where are direct communication such does actuate Each pistons annular having bleed passageway between its permitting equalize stationary. superatmospheric pressure at frequency within ±20% natural resonant frequency.