A universal joint is a joint or coupling connecting rigid rods whose axes are inclined to each other, and is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, connected by a cross shaft.
Universal coupling also called as universal joint shaft or U-joint is a joint that is used to join two rods which are inclined to each other at their axes. This coupling is mostly used in shafts that used to transmit rotary motion or power.
Short for universal joint, a u–joint is a coupling that connects two shafts when their axes are at angles to one another, in a fashion so that both can rotate freely without excess friction. … U–joints are different in design from constant velocity joints.