In a rotary screw compressor, the coupling is the critical mechanical interface between the electric motor and the air-end. It is designed to transmit high torque at high speeds (typically 1,500 to 3,600 RPM) while protecting the precision-matched rotors and motor bearings from the stresses of thermal expansion and vibration. Because screw compressors often run 24/7, the coupling must be robust enough to handle the massive torque required during the "Loading" phase and the high-speed idling of the "Unloading" phase.