NAX flexible couplings can be used where rotational power transmission is needed, by connecting two rotating shafts. The advantage of the NAX couplings is that they allow the shaft’s ends to have a small deviation (axial-radial-angular) between them.
 

At the chapter  INSTALLATION INSTRUCTIONS  we can see the possible deviations, which can occur (misalignment, deformation due to temperature, bearing damage, axes bending under load) and which can be eliminated by the flexible couplings  NAX.
NAX couplings can operate normally, absorbing all the vibrations caused by the misalignment of the machine shafts. On the other hand, we should always try to align the shafts as best as we can, to allow the couplings and specially the rest parts of our engine to have a longer life.