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I am not sure what this thread is about. If we accept that Autotrader adverts are never wrong then the vast majority of BEVs use CVT gearboxes
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I am not sure what this thread is about. If we accept that Autotrader adverts are never wrong then the vast majority of BEVs use CVT gearboxes
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Single fixed gear is standard I believe. The variable frequency drive controls the motor speed but there is obviously a limit to the speed/torque characteristics that can be achieved just using the electronics. I suppose looking it as a black box it would seem to be a bit like CVT but by using electronics rather than conical gears.
 

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Discussion Starter #263
I don't really understand what Koenigsegg is doing with gearbox or replacement-gearbox technology, but they have struck me as trying to innovate in this area:

"....Koenigsegg’s KDD system, invented by Christian von Koenigsegg, uses power-dense electric motors and an innovative coupling system to replace the vehicle’s gearbox. This setup takes advantage of the characteristics of electric motors – high power density, instantaneous throttle response, full torque available from 0 RPM and wide power-band. Additionally, this configuration enables Torque Vectoring, regenerative braking (KERS) and 50 km of emission-free full electric drive. ..."

Before someone gets too bent out of shape by my deviating over-much from the original thread question I asked:
  • Yes, Koenigsegg vehicles are very expensive (not mainstream) but there is some indication that some of their technology innovation could eventually trickle down, including that 20% of them was acquired by NEVS.
  • Yes, Koenigseggs are powered by internal combustion engines, but the Rimac involvement and comments highlight that there is an electric drive aspect to at least some of them.
  • I won't pretend to understand the innovations here, but it does seem like they point the way toward continued innovation in transmitting the energy so that it ends up in propelling the vehicle down the road, including innovation in this area as it pertains to EVs. There may be an aspect to a gearbox technology discussion that a lot of it or all of it is already known settled territory, but with some innovators thinking well outside of convention, I think that holds open that some of the answers may not be what we always expect.
 

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Do you have more to go on than "an innovative coupling system"?

"I won't pretend to understand the innovations here" .. well, no-one should pretend to understand it from that!
 

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🐮:poop: baffles brains! :rolleyes:

It's effectively a single speed car with a lock up torque covertor between the engine and the differential, and electric motors after the final drive to provide the low speed go before the ICE can make considerable power.



There is also a further larger motor/generator on the crank of the ICE to act as starter and fill in the holes in the torque curve. Beautifully engineered but using concepts discarded in the 1890/1900s.

Lots of fancy RWD controls available to stop the rich pratts that buy one from hurting themselves when showing off.

More hype available here: Engineering Explained: How The Koenigsegg Regera Hypercar Drives Without A Gearbox
 

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Just showing how clever they are! If they get it to work properly, that is.

A triumph of imagination and complexity over common sense. Still there may be some technological fall out that benefits the world at large.

Our thanks to the super rich who fund this sort of thing.
 

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🐮:poop: baffles brains! :rolleyes:

It's effectively a single speed car with a lock up torque covertor between the engine and the differential, and electric motors after the final drive to provide the low speed go before the ICE can make considerable power.



There is also a further larger motor/generator on the crank of the ICE to act as starter and fill in the holes in the torque curve. Beautifully engineered but using concepts discarded in the 1890/1900s.

Lots of fancy RWD controls available to stop the rich pratts that buy one from hurting themselves when showing off.

More hype available here: Engineering Explained: How The Koenigsegg Regera Hypercar Drives Without A Gearbox
How boring!

Basically, this is how the GKN system works on the Outlander. In this case there is an Outlander type output on each half shaft rather than on the driveshaft.

Hardly innovative ....

I had hoped for a moment to see something else I had in mind, I was going to suggest it was 'that' but I'll just keep it secret then and maybe file a patent for it.
 

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How boring!

Basically, this is how the GKN system works on the Outlander. In this case there is an Outlander type output on each half shaft rather than on the driveshaft.

Hardly innovative ....

I had hoped for a moment to see something else I had in mind, I was going to suggest it was 'that' but I'll just keep it secret then and maybe file a patent for it.
The innovative part is the flexibility of the engine coupled with its high specific output. This is mainly due to the electronic valve technology allowing optimum timing over the whole rev range.
 

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The innovative part is the flexibility of the engine coupled with its high specific output. This is mainly due to the electronic valve technology allowing optimum timing over the whole rev range.
Great, so they have made innovations to an ICE .. like they often do ...

... and that interests me because ..... ?
 

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Clearly it doesn't, but you should address that to those who believe that bigger is better and that we proles will benefit from the crumbs from the rich people's table.
 

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Clearly it doesn't, but you should address that to those who believe that bigger is better and that we proles will benefit from the crumbs from the rich people's table.
No interest of mine. They have re-invented the GKN system as far as I can see. Nothing innovative here I can tell.

It's why I have to admit GKN delivered a bit of a blinder. A pretty simple setup, engine mounted generator with a serial motor that can lock up into what is effectively 4th gear (of the ICE version). Doing that they were able to deliver a system years earlier than most anyone else (comparable with Voltec) and make it robust and 'effective'. Mitsubishi won big on the back of that. Doesn't need to be 'perfectly efficient' just needs to be 'in the market' and at a decent price.

In fact, the GKN Outlander story is the exact antithesis of @metastable - pretty inefficient and much better ways to do it, but is basically the most sold PHEV because of price and simply time to development put it on the market before anyone else even blinked, all down to its unsophisticated simplicity.

@metastable;- Do you see that 'unsophisticated simplicity' wins when its the only product on the market? You can worry about getting it 'all perfectly efficient' once the rest go bust!
 

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They have re-invented the GKN system as far as I can see. Nothing innovative here I can tell.
The GKN system is more complicated in a lot of ways but has a lot less flexible ICE to deal with.
 

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If single motor, multi-gear offered a performance advantage over multimotor it would’ve been done in this car—

“Ford has created a version of its Mustang Mach-E SUV with seven electric motors that can produce a total of up to 1,400 horsepower”

 

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Discussion Starter #276
Op-ed against two-speed gearboxes in EVs. While it's a bit aggressive, I think the summary of the thinking and evolution of desgin at Rimac is really interesting.

 

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It's an engineering exercise in optimisation. There is no 'perfect' for all cases. TBH, I shouldn't even need to say that, it should be blindingly obvious to any engineer and non-engineer alike.

(This thread suggests not as blindingly obvious as I had thought!)
 

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Discussion Starter #278
It's an engineering exercise in optimisation. There is no 'perfect' for all cases. TBH, I shouldn't even need to say that, it should be blindingly obvious to any engineer and non-engineer alike.

(This thread suggests not as blindingly obvious as I had thought!)
I'm not sure exactly whom you are referring to on this or that aspect, but before I started the thread I thought to myself that this is not a matter of finding a final perfect answer in all cases, and I still think so. Still, this is not at all just about engineering, but it is also about markets and consumer preferences. These are still relatively early days in the industry and it will be interesting (to me anyway) to see which way both suppliers and buyers go on various points.
 

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I'm not sure exactly whom you are referring to on this or that aspect,
Well, metastable ... I was just trying to slightly-avoid looking like I was victimising him.

but before I started the thread I thought to myself that this is not a matter of finding a final perfect answer in all cases, and I still think so. Still, this is not at all just about engineering, but it is also about markets and consumer preferences. These are still relatively early days in the industry and it will be interesting (to me anyway) to see which way both suppliers and buyers go on various points.
Quite so. This is the thing. What does the application/customer/market want and need.
 

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Discussion Starter #280
"[...]
Quite so. This is the thing. What does the application/customer/market want and need.
What did you think of Mate Rimac's efforts to avoid using two speed gearbox for the next Rimac? Note this is not a loaded question, and I'm not saying it's a mainstream vehicle, I just respect him and I liked hearing the story.
Starting around 10:20:
 
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