A coupling transmits power from a driver to a driven piece of equipment. The driver can be anything from an electric motor to a steam turbine, and the driven equipment can be a gearbox, fan or pump. While the coupling is often viewed as the weak link in the pump assembly, replacing a coupling element is still much easier than replacing a sheared shaft. The best approach is to carefully consider all design criteria. Typically, these include torque, shaft misalignment, stiffness, rpm, inertia, space requirements, and shaft mounting. A coupling that addresses all of these issues will ultimately perform as required in the applicatio.
