DEVICE FOR HYDRAULIC PROTECTION OF OIL-FILLED SUBMERSIBLE MOTOR Russian patent published in 1998 - IPC

FIELD: electrical engineering. SUBSTANCE: hydraulic protector 1 has top, intermediate, and bottom end seals 9, 10, and 11, respectively, arranged in tandem and top flexible diaphragm 13 whose inner space communicates with outer space of bottom diaphragm 15. The latter is placed between bottom and intermediate end seals 11 and 10; top diaphragm 13 is installed between top and intermediate seals 9 and 10. Outer surface of top diaphragm 13 communicates with surrounding atmosphere. Pressure drop built up due to difference between oil and stratal water is taken by bottom end seal 11. Top end seal 9 does not take this pressure drop. EFFECT: improved reliability and service life of hydraulic protector and motor as a whole. 2 dwg