Jaw Couplings


  • High torque capabilities
  • Different material choices for the spider allow the user to choose torsional stiffness
  • Somewhat “fail-safe”, in the sense that the driving hub will continue to turn the driven hub after failure of the spider
  • Easy installation in blind or difficult installations – all jaw couplings have through bores
  • Dampens variations or spikes in torque, usually caused by the driving element, protecting the support bearings and the driven component, and reducing vibration
  • Wear element can be reversed before being replaced, doubling life
  • Rugged, can function well in harsh environments
  • Replaceable, inexpensive wear element


  • Relatively high reactive forces exerted on support bearings, proportional to misalignment
  • Even preloaded, so-called “zero backlash” jaw couplings have considerable wind-up, which is essentially the same as backlash, and disqualifies jaw couplings from servo applications
  • Accommodates relatively small misalignments, considering large size of couplings

Typical Applications:

Pumps, particularly gear, lobe, vane, and reciprocating pumps; also applications involving piston motors, or any system with high torque and vibration, where relative angular location of the two shafts need not remain constant. High-temp spider option good for down-hole directional drilling applications.


  • Materials for midsection: Urethane: Good all-around performance; NBR: More torsional dampening; high-temperature rubber: For high-temperature applications or applications exposed to chemicals incompatible with other elastomers.
  • Materials for hub: Alloy 7075 aluminum, alloy 303 stainless steel, nickel plated alloy 1018 steel
  • Shaft attachment options: Set screw without keyway, set screw with keyway, clamping without keyway, clamping with keyway

Why OEP?

Advantages of OEP’s Jaw Couplings, over jaw couplings from other manufacturers:

  • Miniature sizes available
  • Spiders available in various materials and hardness; hubs available in various materials
  • All hubs very precisely machined from bar: No cheap castings or powdered metal parts, resulting in better overall and more consistent performance
  • Unique geometry of spider, and low coefficient of friction between spider and hubs, minimizes reactive forces, and reduces heating of spider during operation

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