Identifying various parts
I can't identify the black parts.

The toothed wheel is a string reel spool.

The rest of the parts appear to have come from a Robotics Invention System set from RCX-era Mindstorms:

The grey wheels with a different material on the inside are part 2983. None of those sets have 5 of these, though.
The grey bricks are touch sensors.
The white wheels are conveyer belt wheels.