Slip rings are a way of making an electrical connection through a rotating assembly. They are normally copper bands, molded onto an insulating material, then pressed on the steel shaft of the rotor.
Each end of the rotor winding is connected to one of the copper bands, so that as the rotor rotates, the brushes can make a connection with each end of the winding.
The brushes conduct the current between stationary and moving parts. They are made of a combination of copper and carbon, and are carried in brush holders mounted in the end frame.
