UNIVERSAL HYDRAULIC SUSPENDED PIPE WRENCH Russian patent published in 2005 - IPC

FIELD: drilling oil and gas wells; devices for screwing and unscrewing casing pipes.

SUBSTANCE: proposed wrench includes power unit in form of electric motor, hydraulic pump with constant power regulator and tank filled with working medium. Actuating mechanism includes hydraulic motor, gearbox, rotor with pipe grip, movable doors with locks and hydraulic distributor. Constant power regulator is provided with delay unit in form of prestressed spring. Axial-flow piston-type pump is used as hydraulic pump; it is provided with movable unit with spring and its pistons are arranged in inclined position. Constant power regulator inlet is connected with main hydraulic line and its outlet is connected with cylindrical movable unit of hydraulic pump. Constant power regulator may be switched-off by delay unit. Regulator is switched on when output power of power unit and output of hydraulic pump reach the magnitudes preset by the following formulae: where N, are respectively output power and normal output power of power unit; Q are respectively output and nominal output of hydraulic pump; P are respectively pressure and nominal pressure of working medium in hydraulic line, k is proportionality factor equal to 1.

EFFECT: enhanced efficiency, reduced wear; increased universality factor.

4 dwg