Low cost AC drive motor / homebuilt hybrid retrofit

[usedgeo]

I have admired the persistance and determination to save a few bucks that has gone into project forkenswift. I think I would not be up to that kind of project but a question surfaced in my mind today. It might be there but I did not find the answer in my searches of the archives. GM is now using the alternator as a motor in some vehicles and calling it a hybrid. Just how much would it take to turn a 165 amp 12 volt alternator into a 3 phase motor and how much power might a person get from it before it got too hot. I would like a 5-10 hp AC motor and what the heck maybe a guy could make one.

My new to me 2001 Saturn has impressed me very favourably and I think the addition of a 5 hp pusher wheel might be in the cards. I have seen the picture of the Insight with the fifth wheel.

Anybody turning ordinary alternators into motors. It would certainly take the right controller and some "field current" with the original rotor.

I am looking for low cost too but maybe this is not the place to look.

Thanks, Ernie

[landspeed]

I have thought about this a lot myself, and have come to the conclusion that the best idea would be to install a *small* AC or DC motor, and connect it using a drivebelt, to the crankshaft pulley than connects to the alternator and so forth.

One thing to consider with this option is that, it would only work when the engine is on and running, and therefore, one big advantage (prolonged engine-off coasting with electrical drive to stop/reduce speed loss) would be lost.

Another thing to consider is that, if you are driving with the car at 2000rpm, it might take 10 'units per second' of fuel to just turn the engine at 2000rpm, and then an extra 2 to give a lot of acceleration. This means that the effects of the motor may be less than expected. A more positive way to look at it is that, even if you use a fifth wheel or put the motor on or near the alternator, the fuel savings would be identical, as long as you are using the engine in gear while using the electric motor or fifth wheel.

If you keep thinking about this, one possiblity (if you have a manual gearbox) is to get the motor attached to the output shaft, before/on the diff (would need some custom machining), but this would give a brilliant way to power the car with the engine in neutral, or off, or with the engine running, and could also be used for regen if you had the correct type of motor.

Good luck with this - this is something I personally plan for my car, likely in 2008. Just waiting for word back on price from the large form factor NiMH supplier I found :)

[MetroMPG]

I don't have much to offer directly, but the question of alternators as motors has come up on the EVDL. You may find some info by searching the archive here: http://autos.groups.yahoo.com/group/ev-list-archive/

If I recally, the consensus was that a conventional alterntor would make a poor motor.

If you keep thinking about this, one possiblity (if you have a manual gearbox) is to get the motor attached to the output shaft, before/on the diff (would need some custom machining), but this would give a brilliant way to power the car with the engine in neutral, or off, or with the engine running, and could also be used for regen if you had the correct type of motor.

I'm with you on that, landspeed.

A potentially simpler option would be to attach (via pulleys & a cogged belt) a small-ish motor to the drive shaft/half shaft. Use a freewheeling clutch on the motor, and you've created a cheap dual mode hybrid.

The car can be driven electrically with the engine off and the transmission in neutral, and when being driven by the ICE, there's minimal drag on the belt & freewheel assembly.

I've looked in & under the hood of my car - the problem is there really isn't much room for such a setup. It's too crowded in there.

[skewbe]

To be honest, I've been thinking about how to retrofit a hybrid too. Just thinking.

If there was some way to reuse the gearbox with the motor/generator, i.e. have it coupled to the transmission input shaft with a smaller clutch, then you might have a manageable and efficient system.

1. you could lose the alternator.
2. you could lose the starter (trans in neutral, engine and motor/generator clutches engaged)
3. you could use the motor/generator as a motor at higher speeds and not make it spin faster than necessary.

Maybe a chain sprocket (and a grease shield) could fit in behind the throwout bearing in the input shaft? That wouldn't be too fancy of a machining job.

[MetroMPG]

Maybe a chain sprocket (and a grease shield) could fit in behind the throwout bearing in the input shaft? That wouldn't be too fancy of a machining job.

There's not much room. I've looked :)

[Silveredwings]

I've thought of this many times as well so it must be a great idea :D , but alas, I must agree with the others on the alternator thing. The first problem is 165 Amp x 12V 'motor' even at 95% effiiciency would give you less than 2.5 HP. If you tried to double it, the motor would likely burn up. Second, you'd have to replace the accessory belt with a much larger cog belt or metal belt of some kind. Third, you'd need a specialized 3-phase AC motor controller. They're pretty pricey.

Now having totally rained on your parade, let me shift gears. A different motor may yet have some promise. Go DC if you need to keep costs down. If you go AC, the motor and controller can run as high as $10K. The biggest problem seems to be how to turn the wheels with the motor (and vice-versa). All front-wheel drive cars I've ever seen give you no easy way to do this. Maybe you could use a cog belt to connect the motor to the inboard end of a half shaft (doing both would mean using 2 motors). The problem with this is that the half shaft pivots up and down. Unless you get the geometry just right to move the motor(s) along with it, you'd quickly 'throw' or destroy the belt. This is not impossible, just a bit of engineering and fabrication.

Alternatively there's the idea of placing the motor into the wheel hub, or on the brake rotor somehow. If you haven't totally given up on an AC controller, and you could somehow add a second rotor, you could attach magnets to the rotor and make a three-phase motor with home-made coils. The reverse has been done elsewhere on the web where folks are making windmill alternators out of surplus brake rotors, magnets and coils. This approach has some pros and cons, but with ingenuity, could be brilliant.

Of course a much simpler approach would be to take a rear-wheel drive car and simply attach a DC motor to the center drive shaft, maybe even inline with it. This is a mostly unexplored configuration. With the kind of experimentation needed to make something like this work in the long run, something that is easier, cheaper, quicker-to-see-results in the short run may turn out to be invaluable.

[MetroMPG]

Maybe you could use a cog belt to connect the motor to the inboard end of a half shaft (doing both would mean using 2 motors)

Not necessarily - only if you want 2-wheel drive. And if you did, you'd have to control the motors somehow to get differential action in turns. I'd just KISS and use a single motor on one half shaft.

The problem with this is that the half shaft pivots up and down. Unless you get the geometry just right to move the motor(s) along with it, you'd quickly 'throw' or destroy the belt. This is not impossible, just a bit of engineering and fabrication.On my car (don't know if it applies to all FWD cars), the inboard half of inboard CV joint is pretty big. Maybe enough room there for a cog. The driveline travel/movement issues go away, but belt routing then becomes the problem to solve.

Of course a much simpler approach would be to take a rear-wheel drive car and simply attach a DC motor to the center drive shaft, maybe even inline with it.Or an AWD car. Such as pretty much any old Subaru, or a Tercel or Civic 4WD wagon.

Another idea I've been mulling over is attaching a cog to one of the rear wheels. You'd still have the issues of motor & belt placement (and suspension travel), but I'd think it'd be easier to solve with the extra space at the rear of the car than in the typical engine compartment of a compact car.

[Silveredwings]

Not necessarily - only if you want 2-wheel drive.
That's what I meant.

And if you did, you'd have to control the motors somehow to get differential action in turns. I'd just KISS and use a single motor on one half shaft.
If you were using 2 motors and they were putting out the same torque (read getting the same current), there wouldn't be a problem. Diffs are needed with a single motor because of the asymetrical torque buildup on a non skid surface. Something has to give.

Or an AWD car. Such as pretty much any old Subaru, or a Tercel or Civic 4WD wagon.
It will work as long as the transmission is not in neutral, otherwise the center diff will spin. [edit: but may not present a problem :confused: ] Alternatively, you could get a 2WD version (no xfer case or center diff) and put the 4WD rear diff/axles in back and then put the electric motor there. The Tercel and Civic sound good. The ScoobyDoos are pretty heavy and are harder to find 2WD versions, but it could work. I think I'd go with a Matrix/Vibe over a sube.

[Ryland]

I found a product that clames "up to 600 amps at 48 volts to the electric motor for acceleration"

http://www.sigmaautomotive.com/electrocharger/electrocharger.php

Estimated retail is $2800.00 USD.

I did a google search for "retrofit hybrid"

[cfg83]

Ryland -

I found a product that clames "up to 600 amps at 48 volts to the electric motor for acceleration"

http://www.sigmaautomotive.com/electrocharger/electrocharger.php

Estimated retail is $2800.00 USD.

I did a google search for "retrofit hybrid"

I found this thingy awhile back and thought it was similar to the Saturn Vue "mild hybrid" setup. So far, it has been "in development" since I saw it over a year ago. Their last progress report does look promising, though :

Jan 24th, '07: From the Inventor: We have been awarded a grant from the State of Texas to develop the Heavy Truck system and the prototype will be ready by the end of August. We are also expecting another grant from the State of Texas on the Mild Hybrid kit and Austin Energy will be the first fleet customer to get our Plug-In hybrid kit. There's alot of things going on and we are getting closer to the launch date for the general public.

(Lots of other fun/whacky stuff on that site, too)

CarloSW2

[MetroMPG]

That's what I meant.

Whoops, right you are. I misread.

Don't forget to put an EV pusher trailer (http://www.metrompg.com/posts/phev-pusher-trailer.htm) on the list of DIY hybrid options.

Someone on the EV list just made an ICE trailer out of half a motorcycle.

Much simpler to construct, swappable between cars. Only downside is... well, it's a trailer.

[Silveredwings]

To do a pure hybrid, you could convert a Metro/Swift with a commonly used motor (http://surpluscenter.com/item.asp?UID=2007020508230405&catname=&qty=1&item=6-936) for $179 plus shipping, an adapter & coupler like this one (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=200073628681) that periodically becomes available, a used low voltage controller, and some batteries. In fact, I'd like to do one of those myself, only ... I can't come up with as cool a name as ForkenSwift. ;)

For long range, just drop in any gas/diesel genset wherever it will fit, or you could tow it behind on a small trailer.

[MetroMPG]

For long range, just drop in any gas/diesel genset wherever it will fit, or you could tow it behind on a small trailer.

We kept the blue ForkenSwift's 3-cyl ICE, partly thinking that we could use it to drive a generator on a trailer (it could run the other forklift's pump motor as the generator)... But a 55 hp engine is probably overkill for that purpose. I'll probably just end up cannibalizing it for the Blackfly.

[jharbert]

I had an idea the other day of adding a small 3-4hp electric motor to our Ranger's driveline. EOC isn't very doable with the pickup - it has power steering that I don't want to lose, and it has an anti-theft circuit on the ignition that makes on-the-fly restarting a bit squirrely - so I spend a fair amount of time coasting in Neutral. A small 3-4hp electric motor would be just the thing for maintaining speed for a few city blocks. Such a small motor could be controlled with a simple On/Off switch rather than a complicate throttle circuit. I bet this would give me a nice bump in city MPG.

[MetroMPG]

Lots of room under the Ranger to do something like that. I'd look at adding a cog to the driveshaft, a belt, and a freewheeling clutch to the motor.

You're right you don't really *need* a controller. As long as you're not trying to drive the vehicle from a standstill with the e-motor, but using it to extend coasts or cruise at low speed once underway via the ICE.

[jharbert]

I was thinking the same thing. Our Ranger has a two-piece driveshaft. The segment between the tranny and the center bearing obviously doesn't move much. It would be perfect for adding a cogged pulley. Finding the right belt to use could be tricky though.

[usedgeo]

Thanks for all the suggestions. The Saturn does have a fixed section in the right side half shaft but I just don't think I could mount anything there. There possibly would be issues with torque steer too. A month or two ago I was thinking trailer, recently I was thinking swing arm, now I am leaning toward small trailer again. Something like Metrompg posted somewhere a while ago.

I do have a surplus generator I have been carrying around for almost 30 years. It might have enough power but the quill shaft drive requires a little extra in terms of bearing support. The Etek and PMG 132 look quite efficient but I am not sure they are powerful enough.

I really am mostly thinking of an assist to extend the glide. I could easily enough start small and see how it goes if I don't sink too much money in things that don't work. I am getting close to 40 mph on a 30 mile round trip commute. If I could get that to 60 mpg with the assist I would call it a success. My current tank is averaging about 40 mph but I can beat 50 mpg on the trip home( slightly down hill) when traffic is not too heavy and I hit mostly green lights.

I have done no aero mods yet either. I know many on this list could get to my goal without the motor assist. I have just begun to experience the benefit of P&G. Even without motor shut down it is significant. I have a long ways to go but I am starting to get the bug.

These guys

http://autos.groups.yahoo.com/group/F2R1-EV/

posted some very good links in message 146

http://autos.groups.yahoo.com/group/F2R1-EV/message/146

Ernie

I was thinking the same thing. Our Ranger has a two-piece driveshaft. The segment between the tranny and the center bearing obviously doesn't move much. It would be perfect for adding a cogged pulley. Finding the right belt to use could be tricky though.

[MetroMPG]

Here's some info & pics of a guy hybridizing a Ford Aspire. Grafted a front half shaft & hub on one of the rear wheels:

Thread: http://autos.groups.yahoo.com/group/ev-list-archive/message/86112

Pic 1: http://www.nimblemotorsports.com/drivenwheel.jpg

Pic 2: http://www.nimblemotorsports.com/motorchain.jpg

[jharbert]

That's pretty slick. One-wheel-drive electric assist could be very helpful for bumping up FE.

[Silveredwings]

Wow, that's amazing. Cool parallel hybrid. I hope to see what kind of results he gets.

I wonder if it could have been any more (or less) work to put a differential in between a pair of halfshafts and drive the diff directly. Less noise, less asymetrical torque, etc. I don't know. He could still do it I suppose.

Still, hats off to the experimenters. That's great.

[MetroMPG]

Good idea - could just hack a transaxle for a compact diff?

[Silveredwings]

Good idea - could just hack a transaxle for a compact diff?
or take one from any small rwd/awd vehicle with workable output flanges, they're pretty compact already and setup to go in in a 'T' configuration. I would think that would take up the least amount of precious passenger compartment.

Considering that others are suggesting making a custom-built oil bath for the chain drive, I'd think the diff starts looking better.