ME Hybrid Technology Patent

[John]

Thanks and credit to Road&Track, and with appreciation for Skank for finding this article, we have learned of a very interesting new hybrid patent that GM has applied for:

GM Is Working on Some Fascinating Active Aero and Hybrid Technology Is this stuff for the mid-engine Corvette? We're not sure, but it's worth checking out regardless.






BY CHRIS PERKINS
SEP 24, 2018

GM VIA USPTO

There've been a lot of rumors swirling around the upcoming mid-engine Corvette, and one of the most intriguing is that it could get some sort of hybrid drivetrain. There's good reason to be skeptical of this, but it's a fun possibility to think about. New patents recently granted to GM, uncovered by Bozi Tatarevic over at Jalopnik, got us thinking about a hybrid mid-engine Corvette even more.


GM VIA USPTO

The first of the two patents found describes an active aerodynamic system, which can vary downforce levels at each axle. Intriguingly, the system is described as being able to work in a car with a hybrid drivetrain. The system is illustrated with the diagram of the current, seventh-generation Corvette seen at the top of this post, though such tech most likely won't feature in the C7.




This system doesn't need an electric motor as part of the drivetrain to work, though. The patent text notes it can work with "zero or multiple" electric motors. So really, we don't know if this points definitively to a mid-engine Corvette with active aero, or if it just describes a new aerodynamic concept, which is able to be used in hybrid vehicles.

Perhaps of more relevance to the C8 Corvette, is the other patent uncovered, which illustrates an active aerodynamic system for a mid-engine car. No hybrid drivetrain is mentioned here.




[GM VIA USPTO

Illustrated in the drawing above, this one's a little more simple, with movable aerodynamic devices at the front and rear. What's interesting is that, as Tatarevic points out, item 104 is an engine, and item 106 is a transaxle. That matches the most likely powertrain layout for the mid-engine Corvette.

The system is described as being able to be applied to devices that can vary downforce levels, improve cooling, and assist with braking. That last thing is particularly interesting, as it sounds like GM could be developing a sort of McLaren-esque air brake.

Will all of this stuff come to the mid-engine Corvette? To be perfectly honest, we don't know. As we said last week when reporting on GM's interesting clutch-by-wire patent, automakers often patent new technologies with no intention of production-car use. And in the most recent mid-engine Corvette spy photos, it looks like the small wing at the back is fixed in place, though that doesn't mean it'll be fixed for all C8s.

[IMG]https://hips.hearstapps.com/hmg-prod.s3.amazonaws.com/images/17-1535988246.jpg?crop=1xw:1xh;center,top&resize=480: *[/IMG]
Detail of the wing on the back of a mid-engine Corvette prototype. CHRIS DOANE

But let's take the C8 out of the equation for a second—there's a lot of interesting engineering detail in these patents that could point to important future technology.

https://www.roadandtrack.com/new-car...o-c8-corvette/

[Daviboss10]

This will probably be only on the top end Zora hypercar (or whatever you decide to call it...). Im curious to see if it will be a Plug-in Hybrid with AWD, or an F1 style ERS system (be it kinetic or heat) just to boost the engine.

[Frenzy36]

202-2 and 202-4 are interesting as could be set up with limit springs which would activate at certain determined speed to create downforce and could also be molded to redirect airflow around the wheels. Then when the vehicle slows down to say 50 mph the springs pull up and deactivate.

[John]

Good catch Frenz36y, and consistent with what we thought would be possible with GM’s March, 2017 active aero patent. Here’s our earlier thread is for more comparisons:

https://www.midenginecorvetteforum.c...re-active-aero

[Quinten]

Lets not forget this...

I posted this on a forum back in December and it seems that few people even saw it. It's interesting because it could be used in anything from a 3-cylinder Malibu to a V8 C8 Corvette. The performance benefits are huge, and it seems to be a performance-minded patent.


AutoGuide found a newly approved GM patent for a twin-charged high compression Hybrid-electric Powertrain. No, you didn’t read that wrong. A supercharger, a turbocharger, a compression ratio ranging from 11:1 to 16:1, and one or more electric motor(s). Do you guys think this could be one of the Powertrains for the C8, and potentially mid-engine, Corvette? Here’s the article:

“After eighteen months in review by the United States Patent and Trademark Office, documents published on October 24, 2017 reveal GM has been granted a patent for an internal combustion engine with elevated compression ratio and multi-stage

The document describes a propulsion system made up of a high compression internal combustion engine which uses a low-flow supercharger in combination with a high-flow turbocharger, linked to “one or more electric motor/generators, none of which are shown”.

It gives us an interesting look at how GM engineers plan to continue producing obscene performance cars like the Corvette ZR1 and Camaro ZL1 1LE in a world of increasingly stringent emission regulations.

The illustrations depict a longitudinally mounted four-cylinder engine, but GM claims the thinking disclosed could be applied to engines with larger cylinder counts as well.




Typically, street legal engines using forced induction operate below a 10.5:1 compression ratio in order to mitigate the effects of pre-detonation. High compression and forced induction don’t usually mix because the extra air-fuel mixture crammed into the cylinder by the turbo or supercharger can ignite prematurely as a result of the elevated cylinder temperatures generated by higher compression ratios.

In order to make high-compression ratios and forced induction viable for an engine that must meet federal requirements, GM is proposing an extreme variation of the Atkinson-cycle using late intake valve closing to allow some of the air-fuel mixture to escape and eliminate the risk of pre-detonation.

Where GM’s patent differs from other Atkinson type applications is the length of time the intake valves would be kept dwelling at peak lift. In the document GM proposes two different methods for generating peak lift for an extended period of time–simple cam lobe profiling in combination with a variable-ratio rocker arm between the valve stem and the cam lobe; or an electro-hydraulic actuator which could replace the conventional camshaft.


Using the cam and rocker solution, GM would employ a “generally flat” portion of the cam lobe which would interact with the variable-ratio rocker arms to jam the intake valve open for a slightly extended period of engine rotation.

The rocker arms would include their own rotatable cam-shaped roller which could alter the duration of peak lift dwell from substantial to insignificant. In another variation, a more traditional cam lobe could interact with a cam follower to achieve the same effect.

Like conventional engines with variable cam and valve technology, the position of the cam and rollers could be changed by high pressure streams of oil shot by phasers. Using this method GM claims the intake valves could be kept at peak lift for an extra 20 degrees of cam rotation.

Should GM replace the cam shaft with a hydraulic or mechanical actuator the ECU would offer much greater control over the valvetrain. The document claims peak intake dwell could be achieved for 5-80 degrees of crankshaft rotation, which is just shy of a quarter rotation, or nearly one full cycle.

GM claims using either solution would yield compression ratios for forced induction engines between 11 and 16:1. To put that in perspective, methanol fueled drag racing engines typically run a 15:1 compression ratio, while Formula 1 cars operate at 17:1. It’s unclear if GM intends to use the system to offer variable compression ratios like other automakers have proposed.

The document also includes new thinking on twincharging and the application of boost pressure. GM says the supercharger could be driven by either the crankshaft or a dedicated electric motor, with the blower’s speed managed by a continuously variable transmission which would control the supercharger independent of engine RPM.

That means the CVT could keep the supercharger pegged at peak boost if necessary, or spooled for low RPM acceleration before the turbocharger clicks on above 3,000 RPM, when enough high-flow exhaust would be available to feed the impeller. The multi-boosted system could be capable of operating sequentially or in tandem based on what the vehicle’s ECU wants, which will, in turn, depend on if it’s been programmed for performance or economy.

It’s unclear how GM is planning to apply the thinking delineated in the patent, but considering the high-performance potential of the proposed system, this could be our first inkling of what’s going to motivate the hybridized mid-engine Corvette.”

[John]

Thank you Quinten!

[JB]

Wow...brainswelling information

[John]

Please, any transmission other than a CVT.

[Shadow]

Ditto! No CVT for me.