OSCILLATOR FOR A DRILL STRING Russian patent published in 2020 - IPC E21B4/02 E21B28/00 

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to hydraulic rotary drilling drives located in wells, in particular to oscillators for a drill string, designed to create hydromechanical impulses acting on a drill string. Oscillator comprises a gerotor screw hydraulic motor, a valve, a plunger module, a transmission shaft, a radial-thrust rotation support, a hydromechanical pulse generator and a spring module. Valve comprises movable valve element and fixed valve element. Movable valve element is equipped with installed in it first valve plate and is movable relative to fixed valve element. Fixed valve element is equipped with the second valve plate installed in it, forms with it a valve hole and has a longitudinal axis. In operation, the valve elements interact to form an alternating fluid flow passage through the valve. Movable valve element is equipped with a tubular shank, which inner cavity is made with possibility to communicate with flow of fluid medium and formation of flow channel through inner cavity of tubular shank. First valve plate is made in the form of the first throttling sleeve with a flow channel fixed to the plunger module. Second valve plate is made in the form of the second throttling sleeve with flow channel attached to the housing. Throttle bushing of fixed valve element is located adjacent to generator of hydromechanical pulses. Internal profile of flow channel of throttle sleeve of fixed valve element is confuser downstream. Plunger module is placed at the inlet of the gerotor screw hydraulic motor and is attached to the inlet part of the rotor of the gerotor screw hydraulic engine. Movable valve element is made in the form of a throttling sleeve with a flow channel attached to the plunger module, the internal profile of which is diffuser downstream. Central longitudinal axis of flow channel installed in plunger module of throttle bushing is shifted relative to central longitudinal axis of rotor of gerotor screw hydraulic engine, its maximum displacement relative to the central longitudinal axis of the rotor of the gerotor screw hydraulic engine is equal to the eccentricity of the central longitudinal axis of the rotor of the gerotor screw hydraulic motor relative to the central longitudinal axis of the elastomer plate in the stator. Radial-thrust support of rotation is arranged in output part of oscillator, and transmission shaft is arranged between output part of rotor of gerotor screw hydraulic engine and inlet part of hollow shaft of radial-thrust rotation support and is attached by one edge to the rotor output of the gerotor screw hydraulic engine, and by the other edge to the shaft radial thrust bearing shaft inlet part.

EFFECT: longer service life and reliability of the oscillator, reduced friction forces of the drill string on the well wall, reduced torsional stresses in the drill string, increased resource of the bit and increased rate of drilling when drilling inclined and horizontal wells.

1 cl, 11 dwg