DOWNHOLE DRIVING UNIT HAVING HYDRAULIC MOTOR WITH STATIC CAM RING Russian patent published in 2016 - IPC E21B23/14 E21B4/04 

FIELD: mining.

SUBSTANCE: group of inventions can be used for delivery of working tool at well bottom. Downhole driving unit comprises a driving unit housing, a hydraulic motor comprising a hydraulic motor housing, hydraulic motor comprising a cam ring, a wheel assembly comprising a stationary part and a rotational part. Stationary part is connected with driving unit housing and rotatably connected with a rotational part. Stationary part and rotational part form hydraulic motor housing. Said hydraulic motor comprises a rotatable section connected with rotational part. Cam ring is connected with or forms part of stationary part of wheel assembly. Rotational part comprises a wheel ring. Bearing is arranged between cam ring and wheel ring. Present invention also relates to a downhole system comprising a driving unit and to use of such driving unit.

EFFECT: higher reliability of downhole drive unit.

20 cl, 18 dwg