| 摘要 |
A hydraulic oil well pump drive system for driving an oil well sucker rod includes a master piston positioned within a master cylinder for axial displacement between first and second ends of the master cylinder. The master piston has a piston drive rod which extends through one end of the master cylinder. The drive rod is connected to a crank pin of an eccentric crank. A center seal assembly divides the master cylinder into a working chamber and a pressure chamber in opposite ends of the master cylinder. Each respective chamber defines a fluid volume which varies with the displacement of the master piston. The master piston displacement creates a bi-directional flow of working fluid from the working chamber. A wellhead hydraulic assembly is operably connected to the oil well sucker rod and is in fluid communication with the master cylinder working chamber to receive the working fluid flow. The wellhead hydraulic assembly is responsive to the working fluid flow to reciprocate an oil well sucker rod at a rate which relates to the rate of master piston displacement. A gas accumulator is in fluid communication with the master cylinder pressure chamber to bias the master piston toward the master cylinder working end, providing an upward biasing force at the wellhead hydraulic assembly.
|
