Advantages:

• 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

Disavantages:

• 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.