Rear Mounted LS1 Pumping Units

Lone Star Artificial Lift’s API Rear Mounted (RM) pumping units present additional benefits not commonly found in conventional pumping units.


The RM unit’s distinctive design geometry exhibits superior efficiency and allows more crank rotation during the upstroke portion of the pumping cycle. This results in less energy used and allows the pump to fill more completely.


RM units coordinate well with applications that require energy savings and wells deeper than 8,000 feet.


RM (API “Rear Mounted”) Geometry
Phased angle cranks create an upstroke of about 190° of crank rotation. Producing less peak torque and lower motor HP required verses Conventional geometry units in wells deeper than 8,000 ft, our RM geometry-pumping unit is ideal. Additionally, when trying to achieve down hole pump over-travel in deep fiberglass rod pumped wells, our RM unit is excellent because the down stroke is slightly faster than the upstroke. The RM pumping unit can reduce the amount of rod buckling that is experienced with Front Mounted API Class III pumping units with steel rod pumping of deep wells.



  • Bolt-on crank arms
  • Straight side cranks (no “hump”)
  • Easy counterweight adjustment
  • Double Circular Arc (DCA) or Involute Gear Reducer
  • Oversized structural beams
  • Largest structural bearings in the industry



  • Full range of counterweight adjustment on both sides of crank arm
  • Gear Assemblies can be flipped over so that the other side of teeth can get wear