Abstract: A downward offset barbell type walking beam compositively balance oil pump, in which at the rear end of the walking beam is mounted a downward offset barbell type balancing device consisting of a shoe plate, a cross shaft and balancing pieces, retains most of the structure of the conventional walking beam oil pump, and has a compact structure, a wide range of moment change, an advantage of saving electricity to a degree of more than 40 percent, and is safe and reliable for operation. The present invention can be applied to the renovation of variety of conventional walking beam oil pumps, used in oil fields, outphase crankshaft oil pumps and walking beam compositively balance oil pumps for the purpose of energy-saving or of promotion of the capacity for oil extraction of the above-mentioned oil pumps.

Abstract: A walking beam balanced span and moment regulating oil pump having an arc, a walking beam, a support, a pitman, a base, a crank, a decelerator, a power machine, and a string device. The upper part or the lower part of the front end of a boom is articulated to the rear end of the walking beam, and between the lower part or the upper part of the boom and the rear end of the walking beam is placed a weighted arm regulator, and a weighted device is installed on the end of the boom. The walking beam balanced span and moment regulating oil pump is simple in structure, easy to operate, reliable in performance and less costly than conventional devices.