SUBMERSIBLE OIL-FILLED ELECTRIC MOTOR Russian patent published in 1995 - IPC

FIELD: liquid production from well. SUBSTANCE: electric motor has cable entry and hydraulic protection device with inner chambers installed in upper portion of motor. Chambers are installed coaxially relative to each other and are limited by flanges. Wire connecting motor winding with cable entry is arranged in oil-filled space of first inner chamber and in through channels made in flanges of hydraulic protection device. Wire is sealed in upper flange. Shaft in hydraulic protection device is embraced by protective cylinder whose upper end is secured in upper flange. Arranged coaxially with cylinder are two diaphragms secured from top on upper flange and from bottom, on flanged portion of protective cylinder. The latter is connected to upper thrust bearing of pivot. Diaphragm, cylinder and housing form, together with flanges, above-indicated inner chambers. First chamber has two spaces filled with oil. Second chamber is limited by inner diaphragm and outer surface of protective cylinder. Release valves of inner chambers are secured in shaft central channel. Input and output of lower valve are connected through radial chambers with first inner chamber and through space between end face seals in upper flange, with second inner chamber. Upper valve is coupled with output of lower valve and outer chamber filled with formation fluid. EFFECT: enhanced reliability of submersible electric motor owing to increase in oil amount in hydraulic protection device. 4 cl, 1 dwg