Gear couplings are mechanical devices used to connect two shafts, allowing them to transmit torque and rotational motion. They consist of two hubs with internal teeth that mesh with external teeth on a central sleeve. This design enables the coupling to accommodate misalignment between the shafts while providing a strong connection. These couplings are commonly used in various applications, including industrial machinery, pumps, and compressors. Their robust construction makes them suitable for high-torque situations, and they can handle both angular and parallel misalignment, ensuring efficient power transmission in demanding environments.