Turbo as a charger?
 

So after viewing the Mercedes F1 Split Turbo explanation video I've had an idea...

Why couldn't we use turbos to charge an electrical system similar to an alternator? Instead of have it belt driven, attach the alternator to the shaft of the turbine...?

Would this even be possible? Or would it generate enough electrical charge?

I think someone mentioned this idea recently and the answer is that turbos spin far faster than alternators, so much so that it would not work.

I'd be interested in figuring out a way around that...

Turbos spin at 80,000 - 200,000 rpm, right? And an alternator spins at about 1/50th that speed?

So wouldn't we just need some way of stepping down the speed of the input to the alternator?

Those step down gear boxes are expensive and the ones I know of are only approved for 40,000 to 50,000 RPM. Most are only used for around half of that.

This system would be so expensive there wouldn't be any point.

How about turning the turbocharger into the generator/alternator. Make the magnets part of the turbine and have the windings inside the turbo?

But I have seen threads like this before, unless a major manufacturer gets involved I don't think this is going anywhere.

IIRC the electric power supply for modern jet aircraft is supplied from a similar setup.

Eh, just mount the magnets directly to the shaft and pickup coils around them. Voltage would be sky-high but feed it through a transformer to jack the amps up and there you are.

I've fantasized about replacing the distro in my pickup with a racing-style magneto-distributor, which really would make the truck my go-to zombie apocalypse choice. Take out the ignition duties and replace all your lights with LEDs and the alternator doesn't have nearly as much to do.

Of course as I said, it's a fantasy.

[edit]
Oops, I see Daschicken (?) has beaten me to it.

There are race cars that are doing this already.

https://en.wikipedia.org/wiki/Porsche_919_Hybrid

How Formula One's Amazing New Hybrid Turbo Engine Works

-soD

I still consider a magneto the best setup for spark-ignition. No wonder they're still prevalent in piston-engined light aircraft and even in some motorcycles. BTW you might remember that some off-road motorcycles, even when fitted with EFI and some weak headlight, don't even have a battery and rely only in the electricity supplied by the magneto. Sure you wouldn't wanna get rid of the battery in your truck because of the starter, but anyway, a magneto is a reasonable option.

Plausible
 

Not true any more.
Brushless DC Motors, Servo Motors, DC Motors, Permenant Magnet AC Motors, AC Servo Motors, Permanent Magnet Synchronous Motors, High Speed Motors, Custom Motors, Gearheads, Encoders, Motion Control, Slotless Motors, Sensorless, Ironless Motors, Vacuu
has this

http://www.koford.com/Generators.pdf[/COLOR]
This is rated up to 400,000 rpm

If you use a waste gate housing you can regulat the shaft Speed. Or even better a VGT (Verible Geometry Turbine )

"Oil pan 4 Those step down gear boxes are expensive and the ones I know of are only approved for 40,000 to 50,000 RPM. Most are only used for around half of that.

This system would be so expensive there wouldn't be any point."

With the gen set parts in the link, the need for a gear box removed ,is this posable?
As for expensive all R&D is. The key is to use off the shelf parts.

My thoughts add 2nd turbocharger ,my rig already has1. Maby a vgt turbo link . Replace the impeller (as it is the thrust bearing pre load) with a spacer and direct cupple the BLDC400, 000 rpm motor/gen to the shaft.
The reason for wanting this not to be in my Intake sys., is simple. Any failure bits and pices would go through the engine, resulting in $1000s of damage. Develop and prove the sys. before putting it on the primary turbo. Also on the primary it would increase lag. And the rule of 1/3. You can recover 1/3 of the waste energy per stage. Eg 160hp into the turbo 120hp bown the pipe and 40hp at the shaft
Gumby stay flexible.