What is the main purpose of a coupling in mechanical systems?

The main purpose of a coupling in mechanical systems is to connect two shafts together and transmit power. Couplings are essential components that allow for the reliable transfer of torque and rotational motion from one shaft to another. They accommodate misalignment between shafts, which can occur due to manufacturing tolerances, thermal expansion, and other factors, ensuring the continuity of motion and preventing undue stress on the connected components.

Additionally, couplings can absorb vibrations, which helps protect machinery and extends the lifespan of both the coupling and the connected equipment. They come in various designs, including flexible and rigid types, each suited for specific applications based on factors like alignment, load capacity, and the nature of motion being transmitted.

While supporting machinery and securing it to the floor are crucial functions for stability and safety in mechanical systems, those tasks do not define the primary role of a coupling. The lubrication of moving parts, although important for reducing friction and wear, is not related to the function of a coupling either. Thus, the correct answer highlights the specific role that couplings play in ensuring efficient power transmission within mechanical systems.