Patent ID: 7896624

Claim:
A pump assembly, comprising: a gear box having an input end and an output end, the gear box being capable of receiving an input of a first speed at the input end and producing an output of a second speed which is one of either faster or slower than the first speed at the output end; a progressive cavity rotary pump receiving rotary input via the output end of the gear box; the gear box having circumferential annular fluid by-pass passages that accommodate a flow of recovered fluids from the progressive cavity rotary pump past the gear box to surface; a pair of pressure compensators positioned above and below the gear box, each of the pressure compensators including a lubricant filled bellows that moves responsively to pressures and temperatures encountered during down hole operation which might otherwise adversely affect the performance of the gear box; and a coupling that connects the input end of the gear box to a sucker rod, the coupling being a telescopic coupling having a male member which slides axially within a female member to accommodate limited axial movement.