DOWNHOLE PUMP MOTOR DRIVE Russian patent published in 2013 - IPC F04D13/10 H02K9/193 

FIELD: engines and pumps.

SUBSTANCE: motor comprises stator composed of tube with magnetic duct fitted therein, three-phase winding and stacks of electric steel sheets making the rotor arranged there inside. Said stacks are separated by, at least, one spacing bearing and fitted on hollow shaft. Copper rods are fitted into grooves of stacks, ends of said rods being welded to short-circuiting copper rings. Stator top end is jointed with head accommodating thrust bearing assy, current lead assy and check valve for forcing oil in. Spline coupling is fitted in motor shaft extension extending through said head for joint with protector. Motor bottom accommodates bed with channels provided with bypass valve for communication with compensator inner chamber and oil feed check valve. Cavity of stator with winding is tightly isolated from that of rotor. Motor head houses bypass valves for oil release from stator winding cavity at heating.

EFFECT: ruled out formation fluid ingress in between rotor and stator, hence, higher reliability.

1 dwg