Typical oil-well pumps use an electric motor to drive a gearbox and lever.
This gas-powered oil-well pump uses high-torque, general-purpose electric clutches from Ogura Industrial Corp. The clutches transmit torques exceeding 200 lb-ft, and withstand harsh environments and heat from high-speed engagement.
The lever moves the pump up and down through a polishing and sucker rod. The action creates suction to draw oil and natural gas up through the well.
The machines use large (15 to 30 hp or more) electric motors that cycle on and off over 100 times/day. But skyrocketing electricity costs have oil companies looking for other prime movers. One alternative is to use natural gas from the well to run a pumping engine. Natural-gas-fired engines develop peak torque at high rpm. But pumping loads tend to be highest at start-up (low rpm), which can stall the engine.
High-torque, general-purpose electric clutches from Ogura Industrial Corp., Somerset, N.J. (www.ogura-clutch.com), let the engines start and reach proper speed without load. The clutch is then engaged and slips slightly as the load accelerates to prevent engine stall. A built-in, double-A-grove-pulley belt drive handles normal loads but slips should there be an overload condition, protecting the pump mechanism from damage.