BMW Patents Its Electric Turbocharger Technology. More Power, Less Lag.

[Martinmaxx]

Originally Posted by Railgun

Or any hybrid.

In regards to the comments about this solving turbo lag...anyone ever hear of a sequential turbo setup? Either via two same sizes turbos (in the case of the RX-7) or a slightly larger secondary (I can't think of an example at the moment).

Granted this is less complicated mechanically and far more compact, turbo lag, when implemented correctly is not noticeable, if present at all. the downside of course is cost.

BMW is already producing sequential turbo setups for 335d and 123d (both diesel). This electromechanical turbo should have instant spool up, much better than any conventional or sequential turbo.

[Railgun]

True, but I would contend that perception of that initial lag would be quite different between a diesel motor and gasoline. Where I've not driven a 335d before, I can only guess that the amount of torque a diesel makes would mask that lag a bit.

[vase330]

Originally Posted by Onehp

+1

Two of these in parallel on a straight six (or V6) could do wonders. And while it seems complex, if these do away with the extra turbo, the twin scroll turbines and associated piping, three wastegates, several actuation valves in the exhaust and inlet piping and VNT manouvering (all of these potentially part of a triturbo set-up), it's actually much less complicated and robust - if they can make the clutches work against the heat!

C-E-R-A-M-C composite clutches anyone? They already make ceramic brakes that last a lifetime for cars such as Vette and some exotics. I am not sure I am the only one getting an epiphany here. They can use these materials to make the clutches. The space shuttle gets considerably hotter and uses a lot of ceramic composites, I don't see any issue other than cost.

[goat128]

patent drawings have to be of a specific format like you see there.

[JRV]

Originally Posted by rosskie

if its very detailed someone can come in and do the same style turbo but different motor or bigger shaft and get away with it.

This way BMW can just say that was our idea u cant use it

exactly...would be foolish to make it all nice for everyone to see and copy before they even make it

[swamp2]

Originally Posted by Jblack4083

exactly!

A +3 (or 4 or whatever) on the cheesy drawings. Patent drawings DO NOT have to be hand drawn nor of any specific format. Certainly the comments about the less detail and the broader the scope apply, but come on hand drawn, really, by BMW...

That being said this could very well be the goodbye to turbo lag.

[maceBR]

simple smart and useful. like all great ideas.. way to go

[captbilly]

The idea of an electric turbocharger goes back at least several decades. The Russians used an electric motor/alternator coupled to a standard turbocharger on an aircraft engine (diesel) back in the 80s. I don't believe that BMW has the patent on the idea of en electric turbo, just the specific setup using the various clutches. It may even be that the only reason for the clutches was to get around the Russian invention, or to allow BMW to give the impression that they had some important IP for electric turbos.

Ultimately the idea goes all the way back to the turbo compound aircraft engines used on post WW2 piston engine airliners. In these engines the turbo is actually used to convert some of the waste energy in the exhaust power back to the engine/propellor (and of course also to power the turbosupercharger). In the turbo compound engines they used gears to feed the power back to the engine rather than the motor generator used on the Russian and BMW systems. These gears were the Achilles heal of the turbo compound engine because it was very difficult to build gearing systems that could match the very high RPM of the turbo to the very low RPM of the big radial engines of the day. A single backfire could tear up the gears, but even barring such a failure the gears were constantly getting beaten by the huge power pulses of the slow turning engine. The Russian application was the first I have seen that used a motor generator to harness some of the waste energy (energy not used by the turbo itself). I am not sure why BMW needs all the clutches and other stuff but perhaps they found that they got somewhat better efficiency under the varying loads of a car vs. the much more constant load in an airplane that the Russian system was meant for.

[Needsdecaf]

Originally Posted by vase330

C-E-R-A-M-C composite clutches anyone? They already make ceramic brakes that last a lifetime for cars such as Vette and some exotics. I am not sure I am the only one getting an epiphany here. They can use these materials to make the clutches. The space shuttle gets considerably hotter and uses a lot of ceramic composites, I don't see any issue other than cost.

Carrera GT used a ceramic clutch. It was unbelievably tricky to engage properly, from all reports. That is the sticky wicket.

perhaps now that gearbox management is by computer and is more intelligent than any human it might work but....

[tuna_hp]

Yeah it seems to me that the clutches are key to why this is such a good electric turbo application. Btw, it's not just old airplane engines, but many auto component companies have been exploring electric turbos for a few years now. Some of them completely separate the turbine from the compressor so they are only connected by electrical wiring, some use an electric motor to help spin up a traditional turbocharger.

The specific benefits of this BMW design seem to be:

-disengaging the turbine during coasting, idling, and launch means the exhaust can spin the turbine to a higher RPM and leave more energy for possible further turbos in a sequential setup to also spin to a higher RPM because it doesn't have to waste energy spinning the compressor (which wouldn't even create boost at that low engine speed, nor would boost be desirable even if it could).

-disengaging the compressor (along with the turbine) during coast and idle means that the electric motor can pre-spool to very high RPM while using relatively little energy because it doesn't have to waste any energy spinning the turbine or compressor around.

-Compared to the purely electric turbo concepts, the BMW design only requires one motor/generator versus having a dedicated motor and a dedicated generator, and maintaining the mode where you have a direct mechanical link between the turbine and compressor should be more efficient than having to convert pneumatic energy>mechanical energy>electrical energy>mechanical energy>pneumatic energy.

Originally Posted by captbilly

The idea of an electric turbocharger goes back at least several decades. The Russians used an electric motor/alternator coupled to a standard turbocharger on an aircraft engine (diesel) back in the 80s. I don't believe that BMW has the patent on the idea of en electric turbo, just the specific setup using the various clutches. It may even be that the only reason for the clutches was to get around the Russian invention, or to allow BMW to give the impression that they had some important IP for electric turbos.

Ultimately the idea goes all the way back to the turbo compound aircraft engines used on post WW2 piston engine airliners. In these engines the turbo is actually used to convert some of the waste energy in the exhaust power back to the engine/propellor (and of course also to power the turbosupercharger). In the turbo compound engines they used gears to feed the power back to the engine rather than the motor generator used on the Russian and BMW systems. These gears were the Achilles heal of the turbo compound engine because it was very difficult to build gearing systems that could match the very high RPM of the turbo to the very low RPM of the big radial engines of the day. A single backfire could tear up the gears, but even barring such a failure the gears were constantly getting beaten by the huge power pulses of the slow turning engine. The Russian application was the first I have seen that used a motor generator to harness some of the waste energy (energy not used by the turbo itself). I am not sure why BMW needs all the clutches and other stuff but perhaps they found that they got somewhat better efficiency under the varying loads of a car vs. the much more constant load in an airplane that the Russian system was meant for.

[mweisdorfer]

There is only one reason for this and it is to put it in the m3. Eventually, you will see it used across the board in all turbo charged BMW's giving better gas mileage as a result.

[Singletrack]

Originally Posted by mweisdorfer

There is only one reason for this and it is to put it in the m3. Eventually, you will see it used across the board in all turbo charged BMW's giving better gas mileage as a result.

It's already in the M550d.

[ScheerSpeed]

pretty cool!

now this will get interesting with how the aftermarket decides to "tune" an electric turbo...

[andrey_gta]

I want to knwo how easy this will be to add the electric turbo to other engines, such as the n52

[BMRLVR]

Originally Posted by Singletrack

It's already in the M550d.

Sorry, but there is no electric turbo on the N57S, just 3 conventional turbos that are brought on-line at different points in the RPM range.

[nsphoto]

Originally Posted by Robin_NL

Tip:Just wait for the prices of second hand 458s to decrease. 9000rpm.

Brilliant hot tip, I concur.

As for the new turbo design, it seems so simple, how is it that someone hasn't applied this concept already years ago?

[bimmerjph]

I just read some where that Audi was developing this too.