HYDRAULIC DOWNHOLE MOTOR WITH HARD-ALLOY RADIAL PLAIN BEARINGS Russian patent published in 2010 - IPC E21B4/02 

FIELD: engines and pumps.

SUBSTANCE: proposed motor comprises housing accommodating rotor driven by fluid medium fed therein and spindle casing housing a shaft running in axial and radial plain bearings. Spindle shaft is coupled, via drive shaft, with engine shaft and with bit. Every radial plain bearing of the spindle represents rotor and stator bushes with circumferential and/or lengthwise rows of hard-alloy plates fitted therein. Said hard-alloy plates are bonded with every bush by impregnating wear-resistant material powder with molten metal metal-binder. Stator bushes are fixed in spindle casing and rotor bushes are coupled with spindle shaft. A portion of fluid medium is forced through the spindle axial and radial plain bearings. The number of hard-alloy plates in rotor bush is one plate less compared with that in stator bush in cross sections of at least one of radial plain bearings that pass through every hard-alloy plate of lengthwise row. Minimum-length hard-alloy plate is arranged in every lengthwise row of said plates on one side of radial plain bearing. Two hard-alloy minimum length plates are arranged on every edge of radial plain bearing in circumferential direction and on both sides of every single-piece hard-alloy plate. Plate length is minimum on opposite edge of aforesaid radial plain bearing. Note here that thickness X of every hard-alloy plate and thickness Y of rotor and stator bushes are related by expression X=(0.045÷0.111)Y at the point of hard-alloy plates joints.

EFFECT: longer life and higher reliability.

5 cl, 8 dwg