HYDROMECHANICAL DRILL JAR Russian patent published in 2015 - IPC E21B31/113 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed device comprises tubular case and hollow shaft jointed by spline pair. Said case is composed of the parts, first seal and splines at inner surface on first edge side and inner ledges, the anvils, at mid part. Said shaft is composed of piston with first seals, threaded shank and splines and hammer. Said case comprises second piston with second seals on second edge side to make the working chamber filled with working oil and including restrictor of working oil communication with fluid chamber composed by shaft larger-diameter bead and circular valve accommodating at least one bypass valve and spring-loaded latch to constrict hollow shaft lengthwise travel relative to tubular case. Shaft lengthwise travel H locked by spring-loaded latch relative to said case at shaft and case extension relative to each other and shaft lengthwise travel h at lengthwise compression of said shaft and case are related by the following relationship: H=(0.85-1.15) h ϕ, where ϕ=1.618…. Case splined part comprises the shaft radial sliding bearing in inner chamber between first seal on the side of the first end and splines. Hollow shaft hammer comprises two shaft radial sliding bearings in outer groove at hollow shaft hammer edge.

EFFECT: higher reliability, longer life, super high impact power in borehole.

6 cl, 8 dwg