HYDRAULIC DOWNHOLE MOTOR WITH DIAMOND PLAIN BEARING Russian patent published in 2008 - IPC E21B4/00 

FIELD: engines and pumps.

SUBSTANCE: invention relates to drives of rotation arranged in the holes and can be used in hydraulic multi-lobe Starrotor screw engines and turbo-drills. The downhole diamond plain bearing engine incorporates a housing accommodating a rotor driven from fluid medium pumped there through and a spindle casing with the shaft fitted therein in radial and axial plain bearings, the spindle shaft being coupled, via drive shaft, with the engine and the bit, a portion of fluid medium being pumped through the aforesaid radial and axial plain bearings. The spindle axial bearing represents two pairs of the rotor and stator rings furnished with a circular row of thrust modules each comprising a layer of polycrystalline diamonds of the module end face arranged opposite the end faces of adjacent modules and getting in contact with one or two end faces in turn, the stator rings being fastened to the spindle casing and the rotor rings being coupled with the spindle shaft. Every pair of the rotor and stator rings features the number of thrust modules of rotor ring smaller than that of the stator rings by unity, while the fluid medium clear area between every two thrust nodules of the rotor ring in contact with every thrust module of the stator ring makes 1.154÷1.618 of the fluid medium clear area between every two thrust modules of the stator ring in contact with every thrust module of the rotor ring. Note here that height H of every thrust module with height Z of the rotor and stator rings are related by the following ratio, i.e. H = (0.255÷0.355)Z.

EFFECT: longer life and higher reliability of spindle axial plain bearing, higher accuracy of borehole curvature parameters and improved performances of drilling.

4 cl, 9 dwg