SMALL SIZE SPINDLE OF SECTIONAL SCREW DOWNHOLE MOTOR Russian patent published in 2018 - IPC E21B4/02 

FIELD: drilling of soil or rock.

SUBSTANCE: invention relates to the field of drilling and can be used in hydraulic downhole motors operating in wells of ultra small diameter and radius of curvature. Downhole motor spindle consists of a body and a nipple, an upper chamber formed above the nipple inside the body, a shaft with an axial flow channel, radial inlets and connections with a cardan or torsion gear from the power sections of a small-sized downhole screw motor, upper and lower radial sliding bearings, axial sliding bearings consisting of the heel and thrust bearings, and n adjustment elements mounted in the housing and on the shaft. Adjusting elements are made in the form of quick-detachable sets of vibration dampers installed in the upper chamber above and below the thrust bearings axial slide bearings with the possibility of preliminary mutual detuning of the calculated natural frequency of the dynamically disturbed mass of the drilling assembly with a chisel and experimentally recorded frequency of the disturbing force that occurs when the bit head is destroyed in the face of a particular rock in such a way that transfer coefficient – the ratio of the amplitude of the force transmitted by the vibration damper on the axial sliding bearings to the maximum amplitude of the disturbing dynamic load that occurs when the face is destroyed by a chisel – less than one is chosen, the dynamic coefficient characterized by a sinusoidal dependence of the phase angle between the disturbing load and the design structural deformation of the quick-detachable kit consisting of n vibration dampers, selected based on the frequency of rotation of the bit and the hardness of a particular rock.

EFFECT: improved reliability of the spindle, downhole motor and drilling assembly as a whole.

11 cl, 28 dwg