DEVICE FOR HYDRALIC PROTECTION OF WELL PUMP ELECTRIC MOTOR Russian patent published in 2009 - IPC F04D13/10 

FIELD: engines and pumps.

SUBSTANCE: invention is related to oil production, in particular, to hydraulic protection of submersible electric centrifugal pumps. Protector of well pump electric motor hydraulic protection comprises, at least, one stage including cylindrical body, tube installed coaxially and surrounding shaft, nipples, damping bushing, end seal, annular piston installed with the possibility of reciprocal motion in annular chamber created in space between body and tube. Piston divides chamber in two sections filled accordingly with dielectric liquid and formation liquid supplied from annular space. Two protective annular elements are fixed to piston end contacting with formation liquid that protrude outside contours of piston and are adjacent to, accordingly, internal surface of body and external surface of tube. Space between annular elements and adjacent surfaces of body and tube is filled with protective lubricant.

EFFECT: prevention of formation liquid percolation in chamber with dielectric liquid, contamination and wear of interacting chamber surfaces.

47 cl, 16 dwg