Quick Reference

Servo Couplings: Bellows vs. Elastomer

Servo couplings are designed to connect two shafts in precision motion control applications. They consist of two hubs connected by a flexible compensating element: metal bellows or elastomer spider. How do you select the best type for your motion control application? While both types provide zero backlash and compensation for shaft mislignment, each has its advantages from torsional stiffness to vibration dampening. 

Elastomer Servo Coupling and Bellows Servo Coupling

Bellows Type

Bellows couplings use stainless steel bellows connected to the clamping hubs via a press fit brass wire providing zero-backlash and extremely high torsional stiffness.

  • High torsionally stiffness
  • Temperatures to 300°C
  • Torque capacity up to 4000 Nm
  • Suitable for all motion control applications

Elastomer Type

Elastomer couplings use an elastomer “spider” between the two clamping hubs. The spider and the clamping hubs interlock with involute jaws/teeth providing zero‑backlash and vibration dampening.

  • Vibration/resonance dampening
  • Temperatures to 120°C
  • Torque capacity up to 2000 Nm
  • Lower cost for less precise applications
  • Plug-in assembly
  • Electrically insulating

Select a coupling by application

Use this quick guide to select the best type of coupling by application priorities.

Your application prioritizes...Use this style coupling...
Ability to repairElastomer
Continuous duty cycleElastomer
Cyclic duty cycleBellows
Electrical insulationElastomer
Extreme temperature rangeBellows
High speedBellows
High torque capacityBellows
High torsional stiffnessBellows
Low-cost solutionElastomer
No maintenanceBellows
Vibration/resonance dampeningElastomer