Couplings are mechanical components that connect two rotating shafts to transmit power. They are essential parts for power transmission between shafts in manufacturing equipment, such as motors and reducers, pumps and motors, and machine tool spindles and drive shafts. Various types include flexible couplings, rigid couplings, Oldham couplings, universal joints, membrane couplings, and rubber couplings, providing functions such as shaft misalignment correction, vibration absorption, and torque limiting. Widely used in machine tools, conveying equipment, pump facilities, and automation lines, they are important connecting components that contribute to bearing protection and improved power transmission efficiency.