Honda 3 Motors in 1 Car
 

Car & Driver Explains Honda Sport Hybrid SH-AWD

When looking to scoop the "Coolest Hybrid Ever", I found this Honda Sport Hybrid SH-AWD. I read this article as well as a few others, and it seems to make a lot of sense. Power the front wheels with an engine, and the rear wheels with 2 electric motors that can also regen brake and go some distance on electric power only.

Also by having a Motor/Generator (MoGen) for each rear wheel, you can vector the power for dynamic handling control, break the inside tire and power the outside to really scoot around corners...blah ditty blah.

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It also makes sense engineering wise to put the fairly heavy MoGens in the back to help with a 50/50 weight distribution.

Sort of a side note, I always figured the best way to make the motors would be to integrate them with the wheels themselves to sort of eliminate moving parts, but thinking about it now I'm not so sure. Seems to me you'd add a lot of "Sprung Weight" to the wheel system, this I understand is undesirable to creating a well mannered ride. We want to keep the wheel & tire system as light as possible. So by running a short drive shaft from each wheel motor that is solidly mounted to the car, you accomplish this. The engineering on a integrated wheel motor would additionally be somewhat complex lending towards costly repairs of unique parts. And unlike the GM Volt that has a pretty complex motor generator system (good luck trying to change a blown winding on that MoGen), Honda will separate the components for all those advantages.

By having the 2 rear drive motors, this lends to a simple mounting which could be somewhat standardized allowing after-market companies to make motors that improve on the Honda offering. Same thing with the battery, if done simply, could allow for after-market batteries to be made, or updated battery technologies to be easily swapped out for the OEM battery.

I'd just make it so you could put a 60HP ICE in a car for cruising and have 50HP in electric motors to get you accelerated when needed for 110HP and oodles of torque down low. Put a fairly strong MoGen in the engine/transmission area to make lots of electric power and load the engine in town so the ICE is near its BSFC sweet spot most of the time. Then run on electric only when the battery is chock full-o-electrons. The front MoGen could also regen break.

Make it all super efficient in a Honda Civic type car with .24 Cd and presto, 65MPG+ without thinking about it. Even though we just thought about it. But that doesn't count. I don't even think they need to bother with the whole vector thing, just keep it simple and make it as efficient as possible.

It looks like this is the direction Honda is going to take in the next few years to start competing with Toyota Prius cars. I think this is a brilliant idea, get the beast of all worlds with an ICE to get you anywhere you want to go for a long trip and electric power to stay close to home.

I question if the "loading" of the inside tire/mogen, as it generates electricity for the outside mogen, will be all that much? It seems to me that it'd take a VERY tight corner to make the speed differences between the two wheels enough to generate meaningful power.

That is what I have been saying for many years, you also get to use much cheaper motors saving a lot of money, the motors don't see the shock of the road so the bearings and windings last longer and they are not moving with the suspension so the electrical cables are not flexing 1000's of times per minute and the only draw back is that you have to put a longer shaft on the motor with a few CV joints in it.

I like the idea of decoupling the electric motor from the engine to run the transmission. And regen braking should be much more efficient too. I hope they get their act together, cause IMA is really poor hybrid technology in my opinion. And they need to actively balance their batteries! I read somewhere that the smaller cars would still be IMA. Hopefully the Insight, Civic and CRZ will get drivetrain upgrades. Such a shame that they got so behind the curve that even Ford overtook them in hybrid tech!

I want to say this is nothing new. I cant remember if its lexus or acura that uses this technology on their awd cars to make them steer better by moving the torque to the wheels on the outside of a turn.

As is most Hondas with an auto gear box comes with grade control logic and not many people like that to begin with. Now we may have the torque going to the outside wheels in a turn too?

Active differentials are lovely if you've ever experienced them. They make a car feel more neutral and keener to turn, and it makes them handle more predictably.

A system like Honda's, which uses electric motors to transfer power from the inside wheel to the outside wheel, could probably be the best solution to power understeer in a front-wheel drive sports car.

Typically that problem is added to a vehicle to keep inexperienced drivers from over driving the vehicle and crashing.