Paper: Mechanical Long-Stroke Pumping Unit

Contrary to present-day methods, this machine operates a sucker rod system at a constant velocity through approximately 80 per cent of the stroking cycle, the balance of the cycle being used to halt the motion and reverse the direction. The reversal action of this machine is accomplished with out the aid of power. To effect the reversal, it utilizes some of the energy put into the system during the constant velocity portion of the stroke. The method of accomplishing this non-power reversal will be fully explained as well as all other engineering features of the equipment. A portion of the paper will deal with the mathematical formulae used to size the equipment for a given set of conditions and what the expected production would be. Also included will be the operating methods and maintenance requirements as well as detailed field performance figures