Abstract: A hydraulic oil well pump drive system for driving an oil well sucker rod includes a wellhead hydraulic assembly that is operably connected to the oil well sucker rod to reciprocate the sucker rod. The wellhead hydraulic assembly includes a hydraulic cylinder and a rod that reciprocates linearly within the hydraulic cylinder. The rod has an upper end with a circumferential groove that receives a split cylindrical bearing. The split cylindrical bearing is has two semicircular halves retained within the groove by the inner walls of the cylinder. The halves are retained vertically, relative to the rod, by the groove itself.

Abstract: 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.

Abstract: A hydraulic oil well pump drive system for driving an oil well sucker rod includes a wellhead hydraulic assembly that is operably connected to the oil well sucker rod to reciprocate the sucker rod. The wellhead hydraulic assembly includes a hydraulic cylinder and a rod that reciprocates linearly within the hydraulic cylinder. The rod has an upper end with a circumferential groove that receives a split cylindrical bearing. The split cylindrical bearing is has two semicircular halves retained within the groove by the inner walls of the cylinder. The halves are retained vertically, relative to the rod, by the groove itself.

Abstract: 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.