I know this is probably one of the most common questions ever for someone who just started studying DC machines and I would probably get told by someone to just read somewhere and force myself to understand how the reversal of current mechanism thing works as there are lots of sources.
But I honestly can't get a good grasp on how the commutator mechanism works. I got the idea that for slip rings, the direction of the current is periodically reversed such as from positive to negative it becomes negative to positive. I associate these polarities with the brushes.
So how does a commutator fit in? Just because we have two different materials at all times against the brushes, how does that aid in reversing the direction? Is it really vague to just associate the polarities with the brushes because their interaction with the material should mean something and become responsible for the change in direction? How does this exactly work?