DEVICE FOR PROTECTING ELECTRIC MOTOR AGAINST STRATAL LIQUID Russian patent published in 2004 - IPC

FIELD: oil industry; oil wells equipped with submersible centrifugal motor-driven pumps. SUBSTANCE: device has journal bearing, at least one compensating unit incorporating section with flexible diaphragm and check valve, and labyrinth section, all arranged in tandem. They are provided with holes to pass motor shaft. Flexible-diaphragm space of compensating unit adjacent to journal bearing is connected through communicating passage to space of this bearing. Check valve of each compensating unit is designed to provide communication between flexible diaphragm space and space downstream of diaphragm of this unit that can communicate through communicating channel with flexible diaphragm space of next compensating unit or with one of spaces of labyrinth section communicating on top with its other space that communicates at bottom with environment. Communicating channels and check valves of device can be made in fittings provided with end seals, each one disposed between journal bearing and flexible-diaphragm section, between flexible-diaphragm section and labyrinth section, and between labyrinth section and environment, respectively. Device may be provided with changeable bottom head for connecting motors of different sizes. EFFECT: facilitated installation of device and extended its repair intervals. 3 cl, 3 dwg