What is the difference between the power lines, USB lines, Signal, and PWM lines in a slip ring?

Question

I'm currently sourcing a slip ring for a robotics gimbal I'm working on, and I'm not too sure how to properly source one.

Currently, I need a slip ring capable of transmitting USB 3.0 data alongside being able to power a BLDC motor (stall current 4.2A, 24V).

During my searches online I've found many different kind of slip rings, I originally thought they were all the same, and just needed to transmit electrical signals. But now I'm getting deeper down the rabbit hole and I'm finding specific circuits meant for power, USB, signal, and PWM.

I'm more on the mech eng side of things so I'm pretty clueless here. Does anyone know what the main differences are? Can I use a regular power slip ring for USB3.0 transmission?

Thanks.

Answer 1

I would hope that the power lines are heavier gauge than any of the other lines.

I would not expect signal lines to pass USB3.0 properly unless specifically stated.

If current (i.e. power) is run through contacts designed to pass "dry signals" (i.e. zero current, no power) it ruins the contact surface so that it can no longer pass dry signals since the signals don't have the energy to punch through the oxide or corrosion layer formed.

But you say gimbal. Does your gimbal spin infinite revolutions? If it doesn't, there is no need for an unreliable, expensive, noisy slip ring. No one likes using slip rings if they don't have to.