ELECTROMECHANICAL CORE DRILLING ASSEMBLY Russian patent published in 2008 - IPC E21B4/04 E21B25/00 H02K17/12 

FIELD: electricity; mining.

SUBSTANCE: assembly contains power supply source with control system, submersible asynchronous three-phase electric motor, rotor of which is connected to core tube with crown, stator connected with top tube, and elastic element that is rigidly fixed with cable lock on one side and electric motor rotor on the other. Source of windings power supply is equipped with single-phase bridge rectifier, rotor of submersible asynchronous three-phase electric motor is made with one pair of explicit poles, and one phase stator winding is serially connected with bridge single-phase rectifier, to the outlet of which by direct current two other phase windings are connected by serially connected between each other ends, which form one pair of poles, with the possibility of rotor fixation with stator by elastic element in initial position, at which longitudinal axis of rotor symmetry coincides with longitudinal axis of symmetry of electromagnet field formed by two serially connected stator windings.

EFFECT: provides possibility of formation of sign-changing moment at low frequencies at considerably smaller angles of rotor turn in relation to stator with preservation of average speed of working tool motion in relation to bottomhole.

3 dwg