SUBMERSIBLE PUMP ASSEMBLY

摘要

A submersible pump assembly is disclosed which may be readily lowered into and raised out of casing and operated downhole in well fluid in the very confined space of casing of an oil well. The submersible pump assembly includes a progressive cavity pump of the Moineau type with a helical stator and a helical rotor. A submersible electric motor filled with a lubricating fluid is located below the pump and drives the pump through a speed reducer. A pressure equalizer is included which provides a pressure equalizer lubricating fluid reservoir for the electric motor and the speed reducer and allows for expansion and contraction in the volume of lubricating fluid. Several embodiments of the submersible pump assembly are disclosed.