Adding rear hub motors to a fwd gas powered vehicule ?

[Hillhater]

It seems you are trying to produce a typical “Hybrid”,… much like a Prius or such but much less capeable or sophisticated.
Your approach may well produce something unique and save some cost, but it wont be easy and may be more difficult than you think ( road legal). It is a route many before you have attempted ( even Ford ) and abandoned after much effort and time.
used Prius’s ( or similar ) have been around for many years now, and can be found cheap ( especially those with battery issues !) , and would seem to be a more realistic solution.

 

[Jeff23spl]

. If someone could pull it off, it would be huge, because for example in the State of California, there could be a mass-transfer of older gas-driving FWD cars to hybrid hub-drive cars. It could make millons, because the conversion is so easy. You just swap out the wheels and add the battery and wiring/controller.

you cannot just replace wheel because the hub would spin freely without pushing the car, you need to replace the whole hub assembly attached to suspension and the part would need to be specifically designed for each model of car.

 

[Jeff23spl]

It seems you are trying to produce a typical “Hybrid”,… much like a Prius or such but much less capeable or sophisticated.
Your approach may well produce something unique and save some cost, but it wont be easy and may be more difficult than you think ( road legal). It is a route many before you have attempted ( even Ford ) and abandoned after much effort and time.
used Prius’s ( or similar ) have been around for many years now, and can be found cheap ( especially those with battery issues !) , and would seem to be a more realistic solution.

I agree with you that it is easier to buy something already made, no doubt about it. and an old prius is getting cheaper these days but as a fan of the DIY hobby, i preffer to build it than buying it....It is not to save money since it would probably be more expensive to mod than buying a whole prius but i expect to have more fun in the project and driving it.

For road legal...i don't plan to have it checked. we dont have annual inspection here so i would just drive it plated as a factory ice. without using lane reserved to ev. I just checked what is involved to have a legal e-scooter plate (40mph limited) on a electric converted road bike project and it get crazy. Among everything, I need an official engeneer to sign my project, i may need high voltage protection loop even for just 72v and a bunch of outdated safety device like if i would be using an old golf cart serial motor that is contactor driven...

 

[Hillhater]

Well maybe if you are not too concerned with cost, you might check out these guys..

Elaphe Announces Production of World’s Highest-Performance In-Wheel Hub Motor - Elaphe

Elaphe announces start of low-volume series manufacturing of Elaphe L1500 in-wheel motor.

in-wheel.com

 

[Jagerbacon]

About 10 years ago a British company produced a hub motor that fits inside a 17" rim and produces 100bhp. Included everything, even brakes, ABS, etc. Now they are called Protean and seem to be based out of China, but they are still not selling motors in small volumes. Their first project car was a newer mini Cooper and they used a generator motor described as 'about the same size as the spare wheel' to run the whole project. ALMOST inked a deal with BMW to make electric Coopers for Califonia only, but that fell through. Their second project was an F150 with the same 4wd, 400hp set up. The current DIY option is to buy a junk EV and swap the axle. I have been wanting to get a Hyper 9 and attach it to the drive shaft (I have a 4KLB RWD SUV) and drive the front wheels.
If you had an electric motor that could only operate at lower speeds, as long as you had a battery disconnect and bearings able to stand the speed, the rear wheels would just free spin, same as they do now. The permanent magnets would generate a EMF, but the coils would not be on, so there would be no interference without the closed loop. It would be the same thing if you took a small motor that upon spinning turns on a lightbulb, disconnect the light (open the loop), but spin the motor.
Make sure and keep your mechanical brakes. Don't try and register it as anything but an ICE. In USA, mostly if you convert an ICE to electric, upon inspection, they check to make sure it doesn't have a gas motor and then stamp it as an EV. If you ran an electric drive train with a generator, just keep it registered as an ICE.

 

[Jagerbacon]

Also, about the unsprung weight issue. The same group I mentioned just upgraded the shocks and claimed that the average driver would be unable to tell a difference. Only a professional driver was able to tell there was added weight to the wheels.

 

[Jagerbacon]

Well maybe if you are not too concerned with cost, you might check out these guys..

Elaphe Announces Production of World’s Highest-Performance In-Wheel Hub Motor - Elaphe

Elaphe announces start of low-volume series manufacturing of Elaphe L1500 in-wheel motor.

in-wheel.com

19" + wheels! Look at what is running on most cars today, 15 to 17" rims, maybe some 18s. Unless it is for a heavy truck conversion, they would need to buy new rims as well. My '94 Ranger had 100hp and I got that hoe up to 92mph on 12s! If someone comes out with a 50HP motor that fits a 14" rim, they will be off to the races with conversion jobs. Ford became so big because they targeted the common consumer, not because they went stright for the top!

 

[Jeff23spl]

About 10 years ago a British company produced a hub motor that fits inside a 17" rim and produces 100bhp. Included everything, even brakes, ABS, etc. .....

In the 1994 Hydro-Quebec came out with a in wheel motor, they put 2 on a chrysler intrepid. The thing didn T went further... The one you talk about probably ran into the same thing/issue later...

For the weight issue, the seller is probably trying to sell the idea that it doesn't change but just replacing heavy wheels for light ones on my compact car make a difference that i can feel. And it is just few pounds. A motor would be a lot more....Maybe it is because i used to track when i was younger and kept a spirited driving but it seem hard to believe that it wouldn't have an impact especially looking at all the ev market that isn't using them at all when most of the slower vehicule are mostly into it.

Today cars have larger brakes and because of it, most off them run 16+ wheel on basic version and 17-18-19 on sport version so wheel size may not be a huge issue.

I did think about something else....a Fifth wheel....My car has a 1ton hitch....I could maybe add an extra wheel there with a motor and a gear box. Everything supported by the extra wheel and the hitch. A quick connector and i could install it and remove it easily. Batteries and controller on the trunck or maybe on the extra wheel also. Ok i would probably have to add extra brace to help against torsion of the hitch but that could make an easier addition VS replacing the whole axles....

 

[esilviu2000]

I was contemplating since a few good years the same idea as you, to hybridize my car by adding in wheel hub electric motors to the rear wheels and the battery in the spare tire well with minimum costs and no modification to the car. After a lot of research, so far, my conclusion to check both conditions is: the best solution is to use pancake axial flux electric motors type and of course an already made kit would be desirable. Other advantage is a very low weight, somewhere around 12kg for a 30kW with 300Nm torque axial motor!
I found this guy which is trying to make this kit available at a very good price REVR | Retrofit
To me this is the best, hassle free solution, as I don't want to modify anything to my rear wheels' hubs, just a bolt-on kit! Take a look and tell us your thoughts!

 

[Jeff23spl]

I found this guy which is trying to make this kit available at a very good price REVR | Retrofit
To me this is the best, hassle free solution, as I don't want to modify anything to my rear wheels' hubs, just a bolt-on kit! Take a look and tell us your thoughts!

It is a nice project with a very good progression
The idea to keep the brake rotor and caliper is perfect.
Where i'm not confident is about the brakets that act as a torque arm. It is abut the size for an ebike but 300nm to move a 12-1500kg is a bit more stress. Car drive-train mounts are way stronger than this and still break over time. (spinning on a wet patch and suddenly getting traction or just handle bad road knock)
It is probably not a big deal to improve while making extra brakets models for different vehicles.

I didn't find the info about rpm/v or nominal rpm and nominal voltage at that 300nm torque.
the car wheel of small cars are usually 2meter circumference revving at about 1000rpm for 120kmh
300nm at 1000 rpm would mean around 31kw (42hp) I would expect it is a peak rating according to the size of the hub
being close to the 12kw 350nm of Qsmotor but those look beefier...


If i get it well, they are looking at making a complete kit. If i were them, i would not sell the motor assembly alone too but for DIY peoples: Kits rarely have what we would like in it and it get expensive to buy just to get the motor...

We will see how it goes....and price tag.....

 

[Hillhater]

300 Nm at the wheel may well be ok for most circumstances, but remember a ICE with 300 Nm at the flywheel will produce more like 3000Nm at the wheels in low gear for starting off on grades etc.
You may want to check the limitations of what a 300Nm inwheel motor might have !

 

[Logic11]

Here's my idea using e-bike motors, controllers, batteries, etc and no electronics wizardry:

Edit: picture wont show? See attached pic below.

This is just an example picture. This applies to any front or rear wheel drive car.

1st NB that the inner CV's outer shell 'stands still' relative to the engine and gearbox, rotation excepted.

See those 6 bolts holding the inner CV Joint onto the gearbox; mount a sprocket on each side as-well.
Now, with proper sprocket ratios you can mount 2 hub or mid drive motors to the gearbox and get whatever wheel rpm you like.
(Belts could also be used, as could geared mid drives)

For control:
e-bikes have torque sensors in the crankset, where you dial in the amount of assist you want on the controller.
Similar torque sensors mounted on the 2 driveshafts would mean full control of the motors with no plumbing into the vehicle's electronics, or any DIY electronic wizardry whatsoever.

The std e-bike brake/regen lever sensor doodat should be simple to integrate into the brake pedal and with the extra momentum of a relatively heavy car, well worth having.

You could also mount a throttle lever (or press button) to the car's gear lever to override the sensors during gear changes or whenever.

NB that there is ASC built into 2WD E-bike controllers.
That part of the controller logic could be used to give you a limited slip differential of sorts if wired to the 2 motors.
ie: If one wheel starts spinning; the ctlr cuts power to that wheel and even switches it to regen/braking mode if necessary, while increasing torque to the other wheel/motor.
IIRC Grin's ctlr can do this..?

And there you are: Done!
For the cost of the E-bike components and some modded/fabricated sprockets and brackets and probably some cooling air ducting.

(If you like the idea:
I'm an engineer going mucking fad and broke, twiddling my thumbs here in The New South Africa as I'm the wrong colour to find employment. ie: I'll work for food and lodging at this point! )

 

[Hillhater]

, with proper sprocket ratios you can mount 2 hub or mid drive motors to the gearbox and get whatever wheel rpm you like.

Sure, but that particular set up looks like the transmission from a Porsche or similar , with a sh1t load of power/ torque,....
...so it would need something more than hub or mid drive motors to overcome the drag of all the mechanicals in the transmission when the main ICE is not driving.

 

[Logic11]

Sure, but that particular set up looks like the transmission from a Porsche or similar , with a sh1t load of power/ torque,....
...so it would need something more than hub or mid drive motors to overcome the drag of all the mechanicals in the transmission when the main ICE is not driving.

That is an old model Alfa Giulietta gearbox by the look of it.

Yes; This is an ICE assist system, as is being discussed in this thread.
I wouldn't try to drive the car with this system without the ICE running if std bike motors etc are used.
You also get motorbike motor kits, but space would be a bigger issue.

With the engine out of gear the differential and the driven side of the gearbox would be turning, but unloaded.
That's not as much parasitic drag as you imagine. Think pushing a small car on a very slight downhill.
But the motors would be geared for the top speeds you want to achieve in a car, reducing the wheel torque and slowing their rpm.
Very low rpm is not efficient at all for these motors.

That said have you compared the torque numbers one sees from the more powerful motors vs smaller ICE engines?

QS Motor Torque Wattage curve

I have a Stealth Bomber bike with QS273 motor, 4KW, 2.5T nominal and 8 KW peak. Detailed specs here. This is paired with 72v 40 ah battery, Savoton 150A controller, 21" moto wheels I am looking at upgrades for a very fast acceleration from standstill, esp 0-30 mph. And top speed with solid...

endless-sphere.com

X2; those are not small numbers.