Couplings serve to connect two shafts in order to transmit the driving power (transmission of speed and torque). 

As different applications lead to most diverse requirements for couplings, there is a large number of different types of couplings with sometimes contradictory characteristics available on the market. 

If possible, the shafts should be supported right besides the couplings in order to avoid unnecessary vibration. This is particularly important for elastic couplings