Enduro dual-motor electric powertrain to get Locking Differentials? - revealed in Rivian patent

[kanundrum]

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[Dark-Fx]

Just because Rivian filed a patent for it doesn't meant we will ever see it.

 

[kurtlikevonnegut]

I wonder how similar to the Conserve mode disconnects this will be and if having that capability influenced this at all.

It is not surprising to me at all that they would have this as part of the dual motor configuration to maintain off-road capability without independent drive power at each wheel.

 

[MountainBikeDude]

Just because Rivian filed a patent for it doesn't meant we will ever see it.

I would say this one is most likely to see the light of day. A dual motor adventure vehicle without locking diff's would make them look amateurish.

 

[Autolycus]

This reads to me like they'll have "torque-vectoring differentials" controlled by software. In addition, they'll have clutches, probably like they've got for the current conserve mode. That combination should allow all the benefits of a "locking" differential when you want those benefits with the benefits of other types of differentials when you don't.

 

[kanundrum]

Just because Rivian filed a patent for it doesn't meant we will ever see it.

Well I did put a "?" on it as my caveat. I still remember the 800v switching days.

 

[Autolycus]

Well I did put a "?" on it as my caveat. I still remember the 800v switching days.

Ugg... there are so many reasons that I'm tempted to wait for a dual-motor R1S, but I'm just not confident my Q5 is going to last until 2024! That said, my current delivery estimate of July-Sept could put be awfully close to 2024 anyway.

If Rivian offered a discount on the dual motor config for pre-3/1/22 reservation holders (maybe $2-4k off our locked-in quad motor price?), it'd be really tempting to wait it out if I knew I'd get delivery in Jan-Feb 2024.

 

[electruck]

FYI, Conserve mode does not currently utilize clutches for the disconnects.

 

[Dark-Fx]

FYI, Conserve mode does not currently utilize clutches for the disconnects.

"clutch : a coupling used to connect and disconnect a driving and a driven part (such as an engine and a transmission) of a mechanism "

They are definitely still a clutch mechanism. It just doesn't function the same way as a typical clutch for a manual transmission does.

 

[mikehmb]

Yup. Not a friction clutch, but a magnetically-actuated one with interlocking gear/teeth. It’s a cool setup. One of the Munro tear downs highlights the mechanism.

 

[electruck]

"clutch : a coupling used to connect and disconnect a driving and a driven part (such as an engine and a transmission) of a mechanism "

They are definitely still a clutch mechanism. It just doesn't function the same way as a typical clutch for a manual transmission does.

Yes, this is correct.

The point I wanted to make was that the current axle disconnect is not the type of clutch that would be used in a torque vectoring differential.

edit: I was specifically countering the statement from Autolycus that "they'll have clutches, probably like they've got for the current conserve mode"... as the unit will certainly have clutches but specifically not the type they've got for current Conserve mode.

 

[zefram47]

Rather than locking diffs for the dual-motor variant, this sounds more like locking diffs for the quad-motor variant. It talks about two drivetrains being able to be linked at their outputs. If they ever did this, it would be interesting because it would potentially allow for 4WD operation using only two of the four motors, assuming some sort of LSD vs a full locker. That said, for off-road use, you'd still want a full locker since a non clutch-type LSD would turn into an open diff as soon as you lift a wheel. It might also allow "Conserve" mode with only 1 motor in operation.

 

[Autolycus]

Yes, this is correct.

The point I wanted to make was that the current axle disconnect is not the type of clutch that would be used in a torque vectoring differential.

edit: I was specifically countering the statement from Autolycus that "they'll have clutches, probably like they've got for the current conserve mode"... as the unit will certainly have clutches but specifically not the type they've got for current Conserve mode.

Yeah, I worded that fairly broadly. In the end, we don't really know what the differentials and clutch packs will look like, but they will ultimately need some way to completely disconnect both half-shafts from the engine at the same time for them to be able to operate in single-motor mode. I'm not a mechanical engineer or car guy, but my limited understanding of differentials is that they generally can't completely disconnect all power from both wheels on an axle. (well, they can, but that's controlled by a 3rd differential).

 

[electruck]

Rather than locking diffs for the dual-motor variant, this sounds more like locking diffs for the quad-motor variant. It talks about two drivetrains being able to be linked at their outputs. If they ever did this, it would be interesting because it would potentially allow for...

Yes, I agree, after finally taking a quick look at the document, it does not suggest application to Rivian's expected Enduro dual motor setup but rather is a more flexible (if also more complex) way to manage the output of dual motors on the same axle (as in a quad motor setup).

 

[kanundrum]

Yes, I agree, after finally taking a quick look at the document, it does not suggest application to Rivian's expected Enduro dual motor setup but rather is a more flexible (if also more complex) way to manage the output of dual motors on the same axle (as in a quad motor setup).

AFAIK they are planning on producing all quad motors with enduro motor setup once its finalized to get away from suppliers and produce all motors in house? I thought that was the goal but could be wrong.

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