The ultimate articulation?

[Ratbert]

Imagine how much articulation a vehicle could achieve if there were no axles to limit it. They're making significant progress that could eventually result in some killer off road EVs.

They'd obviously need to provide sufficient gearing. And it'll take "a while" before they're durable enough, but damn, keep that old 3.6L up front charging the battery and you could have an incredibly capable rig.

https://www.motortrend.com/news/orb...rid-motor-technology-torque-cost-performance/

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[C.Sco]

That's interesting, so if I'm reading this right (and I just skimmed it really quick), it sounds like the motors are basically in the wheel hub assembly, so there are actually zero axles whatsoever? Pretty neat idea, the articulation limit could pretty much be whatever the engineer wants it to be. IF you somehow also had the steering system (motors) integrated into the front hub assemblies, you could have like a 12 foot high lift if you wanted and all you'd need are some extensions cords for the wiring lol

 

[azwjowner]

My dream is this but I don't need a big 3.6L. How about a 1.5L four or three cylinder that keeps the battery charged.

 

[Pape]

I think they already have something along that line without throwing 480v in the mud :P

 

[Ratbert]

That's interesting, so if I'm reading this right (and I just skimmed it really quick), it sounds like the motors are basically in the wheel hub assembly, so there are actually zero axles whatsoever? Pretty neat idea, the articulation limit could pretty much be whatever the engineer wants it to be. IF you somehow also had the steering system (motors) integrated into the front hub assemblies, you could have like a 12 foot high lift if you wanted and all you'd need are some extensions cords for the wiring lol

I don't see a reason to have axles if the power is already at each wheel.

 

[Ratbert]

My dream is this but I don't need a big 3.6L. How about a 1.5L four or three cylinder that keeps the battery charged.

Yep, anything small / cheap / reliable that doesn't have a turbo. They went with the 3.6L in the Ramcharger. That's the only reason I mentioned it, which was probably a bad idea.

It doesn't need to keep it charged. Just needs to charge it when needed and potentially provide extra juice under load.

 

[roaniecowpony]

I don't see a reason to have axles if the power is already at each wheel.

Still have to have suspension and attachment for the hub axis along with steering.

 

[Pape]

Still have to have suspension and attachment for the hub axis along with steering.

Plus cables routing

 

[Ratbert]

Still have to have suspension and attachment for the hub axis along with steering.

Absolutely, but fundamentally axles are there to deliver torque. How you connect the wheels to the vehicle and manage their position is unrelated when the torque is already at the wheel.

 

[yokramer]

Still have to have suspension and attachment for the hub axis along with steering.

The motor is the hub, the wheel will essentially bolt DIRECTLY to the part driving it with no need for anything in between.

 

[roaniecowpony]

We all know having electric motors at the wheels eliminates a lot of stuff, but it also has to retain a lot of stuff too. This type of design has its own challenges.

 

[Ratbert]

We all know having electric motors at the wheels eliminates a lot of stuff, but it also has to retain a lot of stuff too. This type of design has its own challenges.

Absolutely. There are tradeoffs.

Introduce batteries and new motors w/associated complexity.

Discard drive shafts, axles, differentials, transfer cases, lockers, etc.

I'm now questioning how useful that articulation would be without a solid axle providing downward force.

 

[alphawolff]

Imagine how much articulation a vehicle could achieve if there were no axles to limit it. They're making significant progress that could eventually result in some killer off road EVs.

They'd obviously need to provide sufficient gearing. And it'll take "a while" before they're durable enough, but damn, keep that old 3.6L up front charging the battery and you could have an incredibly capable rig.

https://www.motortrend.com/news/orb...rid-motor-technology-torque-cost-performance/

Well if you remove the axles you're effectively forcing each wheel hub to become an electric motor. There's a lot of additional complexity involved with that, especially considering adding braking forces to the same hub.

While theoretically the best version of EV motors, I don't think it'd be practical for mass application due to the additional weight, heat, etc being inserted into each wheel. You'd also have thick EV harnesses being bent all the time when during the wheel. Not ideal from a reliability standpoint

 

[dchemphill1]

If I understand this correctly, without axle and each wheel free to flex unlimited, would this not put tremendous torque on the vehicle body? Would it hold up? Or what other trade offs occur? Just thinking out loud.

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