When the shafts are slightly misaligned then most suitable coupling to connect them as

Explanation:

Flexible Coupling

• A flexible coupling is a type of coupling used to connect two shafts while accommodating minor misalignments, whether angular, axial, or radial, between the shafts. This coupling is specifically designed to transmit torque while allowing for flexibility, which helps in protecting the machinery components from stress and potential damage caused by misalignment.
• Flexible couplings work by incorporating elements that can deform or adjust to accommodate misalignment. These elements may include elastomers, springs, or other flexible components. When the shafts are slightly misaligned, the flexible coupling compensates for the misalignment by absorbing the resulting stresses and vibrations, ensuring smooth transmission of torque.

Applications: Flexible couplings are widely used in applications where minor misalignments are expected, such as in pumps, compressors, blowers, and conveyor systems. They are also employed in systems that require vibration damping or shock absorption.

Important Information

To further understand the analysis, let’s evaluate the other options:

Rigid coupling

• Rigid couplings are designed to connect perfectly aligned shafts. They do not allow for any misalignment and will transmit torque directly. If rigid couplings are used in a system where the shafts are slightly misaligned, it can lead to excessive stress on the shafts, bearings, and other components, causing premature failure and operational issues.

Oldham-hook coupling

• Oldham couplings are a type of flexible coupling specifically designed to accommodate large radial misalignments. However, they are not as commonly used for minor misalignments and are typically employed in applications requiring precise alignment adjustments. While they can handle slight misalignments, they are less efficient compared to standard flexible couplings for general-purpose applications.