I'll take a stab at it.
I have one of the older Fury 2400 systems, with the 16" floor tool.
The spinner, arms and nozzels are the same as a regular surface cleaner. The housing is made of two shells that fit together with a small gap and runners between them, that direct the vacuum flow to the hose fitting. These systems require a tremendous amount of vacuum. A heavy duty shop vac unit won't come close to doing it. My system uses a roots type blower run by a 16 HP Briggs motor. I think it's the same vac setup as a carpet cleaning unit.
Even with this much CFM, the unit must be somewhat "sealed" to the surface with a tight perimeter brush and only works well on flat, even surfaces.
We don't use ours very much, but in some situations, it's the only way.
See ya,
Rick