A Rotary Union is a mechanical device that allows the transfer of fluids or gases between stationary and rotating parts of a machine. It typically consists of a rotating component and a stationary component, connected by a series of seals and bearings. This design enables the continuous flow of substances while minimizing leaks and wear. Rotary unions are commonly used in various applications, including industrial machinery, robotics, and aerospace systems. They play a crucial role in systems that require the rotation of parts, such as hydraulic systems and cooling systems, ensuring efficient operation and reliability.