What Is Coupling? The term "coupling" refers to a type of mechanical component that connects two shafts to transfer energy from one side of the shaft to the driving side, while taking care of the mount error (misalignment) or misalignment. between the shafts. Coupling in the machine sector is understood to be "a part that connects two shafts together" and is commonly referred to as "coupling", "shaft coupling" or "joint". ...