ROTARY DRILLING RIG WITH TORQUE AMPLIFIER Russian patent published in 1998 - IPC

FIELD: mining equipment. SUBSTANCE: this drilling rig is designed on principle of coaxial mounting of all component units. Kelly stem is installed in rotor of driving electric motor for possible axial displacement relative to internal surface of rotor. Steplessly regulated driving electric motor is provided with epicyclic device for increasing nominal value of electric motor torque. Device is mounted directly on upper end of rotor and coaxially with it for synchronous rotation. Kelly stem is connected with clamping chuck of epicyclic device and receives from it rotation with increased torque which is controlled by regulating rotation frequency of driving electric motor. Mechanism of axial feed of kelly stem with drilling tool is made in the form of two hydraulic cylinders secured on housing of driving electric motor coaxial with it and kelly stem. Hydraulic cylinders when moving along their rods stationary secured on lower and upper cross-members transmit preset axial thrust created by pistons of hydraulic cylinders to drilling tool. Upper cross-member is connected with two telescopic struts which ensure rigidity of entire structure, and together with cross-member pivotally (with fixing) mounted on base they provide conditions for drilling inclined bore-holes. EFFECT: high efficiency. 4 dwg