What is a rigid coupling used for?

A rigid coupling is specifically designed to connect two individual shafts that are aligned along the same axis. The primary purpose of this connection is to effectively transfer torque and rotational motion from one shaft to another without introducing any flexibility or misalignment in the coupling itself.

When two lengths of shafts are joined using a rigid coupling, the resulting assembly creates a solid, unified structure. This setup ensures that the power transmission is efficient and reliable, without the allowing for any movement or play that could lead to wear or damage over time. Rigid couplings are essential in applications where precise alignment between rotating components is critical.

The other options describe scenarios that don't align with the purpose of a rigid coupling. For example, joining shafts that are at slight angles or needing flexibility typically calls for flexible couplings, which cater to misalignments. Similarly, joining shafts to sprockets may involve specialized couplings designed to accommodate the specific requirements of chain drive systems.