Originally Posted by thehank
My guess would be a centrifugal style. Basically an electric motor drives a gear reduction impeller. Would probly only be used to spool up the smallest turbo most likely....
They could use higher voltage to run it???? The could use a combo a/c compressor with a built in high voltage alternator that could recharge a small high voltage battery to power it???
How I understand the BMW Electric Turbo Drive Patent it works as follows:
The E-Motor is conected with an clutch directly to the turbo scroll.
- at low rpm it drives the turbo alone, so that it could charge the engine despite low exhaust pressure.
- at middle rpm where are enough exhaust pressure it would be disconected via the clutch.
- at high rpm it reduces boost pressure by working as generator and producing energy for the battery ... because of this there would no need for the (sensitive) pop-off-valves.
Maybe someone has a better explanation!?