FILTER FOR DOWNHOLE HYDRAULIC ENGINE Russian patent published in 2018 - IPC E21B43/08 E21B4/00 

FIELD: machine building.

SUBSTANCE: invention relates to rotational drives disposed in a well, namely to filters for cleaning drilling fluid from mechanical impurities at the entrance to a hydraulic downhole motor. Device comprises a tubular body with threads at the edges, a filter module installed in the tubular body, which includes a filter tube with slotted channels, a fairing located on the inlet side of the tube, an inlet and an outlet sleeve. Filter tube is threaded to the outlet sleeve, the filter module forms a cavity for receiving mechanical impurities inside the tubular body, an elastomer seal is placed between one of said inlet or outlet bushings and the tubular body. Filter tube is designed with an axial displacement of adjacent slot channels relative to each other, in the circumferential row of slit channels located at the outlet of the filter tube, each slit channel is located between a pair of adjacent slit channels made with an axial displacement. Fairing is made with an outer centering belt, the inlet sleeve is made with outwardly directed ribs, mounted on the outer centering belt of the fairing. Outlet portion of the tubular body is formed with a central opening defining a transverse annular projection directed toward the exit of the tubular body. Output sleeve is provided with a latch mechanism in the form of a collet shank equipped with stops on the petals of the collet shank, cooperating with a transverse annular projection directed towards the exit of the tubular body. Entrance edges of outwardly directed ribs at the points of contact with the outer surface of the inlet sleeve are located upstream of the fluid as compared to the input edges of the said fins located at the maximum radial distance.

EFFECT: resource and reliability are increased due to the reduction of the hydroabrasive erosion of the slot channels at the outlet of the filter tube, the structure is simplified.

5 cl, 5 dwg