TURBODRILL WITH BALANCED ROTARY ASSEMBLY Russian patent published in 2006 - IPC E21B4/02 

FIELD: oil and gas well drilling with downhole motors, particularly turbodrills.

SUBSTANCE: turbodrill comprises turbine sections and spindle. Each turbine section includes body, connection subs, shaft, turbine steps, radial bearings, sealing units and ball automatic balancing devices. Counterweights are installed on shaft near each radial bearing. Ball automatic balancing devices are installed in central part of individual turbine steps. Another ball automatic device similar to the first one is built in lower shaft end from lower half-coupling side. Oil lubricating device is installed inside the shaft. Pressure is changed inside lubricating device through membrane piston to equalize pressure between lubricating device, working liquid cavity arranged downstream the upper individual turbine stage and inner cavity of radial bearing provided with sealing units from both sides thereof. Working liquid cavity pressure is equalized through orifices formed in the shaft. One sealing unit is made as unloading piston to apply force to the shaft so that the force is opposite to hydraulic turbine force.

EFFECT: reduced inertial force acted on radial supports and increased turbodrill motor capacity.

1 dwg