DOWNHOLE GYRATOR SCREW-ROTOR HYDRAULIC MACHINE Russian patent published in 2008 - IPC E21B4/02 

FIELD: bottomhole devices, particularly used as motors for oil and gas well drilling and as pumps for oil production.

SUBSTANCE: screw-rotor hydraulic machine comprises working tools made as monolithic stator with continuous inner screw surface having odd-numbered number of teeth and screw monolithic rotor arranged in the stator. Number of rotor teeth is one less than that of stator. Screw-rotor hydraulic machine also has hinge, spindle, journal and thrust bearings. Output shaft is arranged in the spindle. Monolithic rotor comprises three serially arranged members having the same screw surfaces. Extreme members of the rotor have the same lengths. Central rotor member length is equal to sum of two outer member lengths. Axes of adjacent rotor members, namely central and outer ones, as well as rotor teeth tips in adjacent end sections are in anti-phase with one another. Outer rotor members are spaced from central member. Distance between outer rotor members and central member is equal to helical working tool surface leads.

EFFECT: increased service life due to improved inertial force and momentum equilibration.

2 cl, 6 dwg