DOWNHOLE POWER SOURCE Russian patent published in 2001 - IPC

FIELD: auxiliary devices in drilling operations designed for supply of downhole (bottom-hole) telemetering systems for monitoring and automated control of wellbore drilling process. SUBSTANCE: downhole power source consists of hydraulic turbine and electric generator interconnected by means of magnetic coupling. Power source is installed in central channel of some pipe string, for instance, drilling pipe string. Located on shaft with rotor-induction coil are driven half-coupling and hydraulic turbine body accommodating driving halfcoupling and impeller arranged outside. This assembly is located in central channel of one of connecting members of pipe string with help of some supporting-locking device, or by its simple seating into conical seat with small angle of opening of sealing surface. Specific feature of design consists in that rotor-induction coil and driven half-coupling have same number of magnets of alternating polarity and located on shaft with help of spline joints. Poles of magnets of driven half-coupling are shifted relative to poles of rotor-induction coil through open pole pitch to ensure their mutual attraction. Located between their end faces is washer from antifriction elastoplastic material, for instance, of fluoroplastic type or composite on its base. Shaft channel has equal flow area along its entire length and calibrated small hole in its lower end. It is filled with lubricant and closed from the other end of shaft with piston-plug from elastomer. Bodies of hydraulic turbine and electric generator are conjugated by their end faces hardened with high-hardness material and lapped to each other. EFFECT: provided resistance to harmful effects occurring in operation, simplified manufacture of main parts, their assembly, adjustment and servicing. 2 dwg