HYDRAULIC MOTOR DRAWWORKS Russian patent published in 1996 - IPC

FIELD: well drilling equipment; hydraulic motor used as drawworks drum drive. SUBSTANCE: hydraulic motors are installed directly on drum shaft. Rotation of closers in the working hollow of hydraulic motor is synchronized with inner gear with which the closers are engaged with their gears. Hydraulic motors are step-controlled to increase the range of the regulation of speed of lifting drill pipe string and have sectors of round working space independently disengaged. EFFECT: extended range of regulation of drum rotation speed. 5 cl, 9 dwg