Hybrid school bus, is it possible?

[jake_blue]

Originally Posted by skoolie_n00bie

...And forget "standard" all-wheel drive....a single high-output electric motor per WHEEL!!!!

I concepted something like this with a Jeep buddy for an off-road vehicle because axles and drivelines just restrict articulation but I don't foresee that being a factor in a bus. That being said, there could be advantages such as better all-wheel traction control although the turning radius would be limited by the steering wheel limitations. I think Chevy tried an all-wheel steering pickup truck once but the fact that it's not available now suggests that there's more to the physics than just making all wheels able to pivot.

[skoolie_n00bie]

Originally Posted by jake_blue

I concepted something like this with a Jeep buddy for an off-road vehicle because axles and drivelines just restrict articulation but I don't foresee that being a factor in a bus. That being said, there could be advantages such as better all-wheel traction control although the turning radius would be limited by the steering wheel limitations. I think Chevy tried an all-wheel steering pickup truck once but the fact that it's not available now suggests that there's more to the physics than just making all wheels able to pivot.

Oh, i see...what if instead you'd turn the bus "tank-like", 1/2 going front, 1/2 going back? still pretty tight turn radius for a 40footer!
-OR-
switching from FWD, RWD or AWD depending or road conditions...

[jake_blue]

The FWD/RWD/AWD thing is totally feasible in an electric-wheel driven vehicle.

[Hank's P-O-S]

The reminded me of the "original" hybrid electric truck

Chevy-Volt-Truck-Prototype | UtterPower.com


(This is satire, btw)

[Robin97396]

Myself and a friend were trying to do this about 20 years ago using electric forklift motors and batteries. Didn't have enough electrical engineering knowledge to make it happen.
Our idea was to replace the diesel engine and transmission with a diesel generator in a dog nose truck at that time, dispensing of the idea of batteries and the weight issue. Independently powering each wheel would be cool, but again the engineering on that would be spendy. Using standard axles and possibly a motor for each axle for 4x4 or front wheel drive operation seems feasible. You could even run off of one motor if you included a transfer case, but that would require going back to full drive lines in the length of the vehicle.

We were trying to do this for the basic cost of the truck and a diesel generator. We needed electric forklift motors which are available in many auctions. We were unable to interest an electrical engineer in sharing knowledge and eventually timed out on the project.

This presents a number of problems in practice because generators are designed to operate at a certain rpm range. It seems some can have the governor removed and some can't.

This project just kept getting hung up on simple problems because we didn't have enough electrical knowledge to make it happen. There may be a chance of ruining a generator by running it at lower speeds when having lower power requirements. We got as far as we did because of getting things from the auctions at low prices. Fun project that didn't fly.

[jake_blue]

What you want to do is run the generator at its optimal rpm regardless what speed the vehicle is traveling. You do want some batteries so that when generator output exceeds drive demand the surplus power is stored and then when acceleration or climbing demands more power than the generator alone you have reserve power. Also, as far as putting gearing between the drive motor and the drive wheels, you could either opt for a CVT or I think a company called Speedwright makes a two-speed differential that shifts within a range of input RPM. Electric motors have full torque at 0 RPM so the only reason you should still need gearing is to use a smaller capacity motor than the vehicle size demands. An electric forklift motor can have all the torque to get it moving but tops out at maybe 8mph. Taller gears would reduce its weight capacity. If it were me, I'd be looking for salvage Priuses (Priusees? Prii?) And get one Prius motor per wheel! Still probably not enough eHP but for a shade tree project that's about the best alternative I can think of - anything else is huge industrialized motors which won't lend themselves well to a OTR application.

[BlackHeart]

Really old thread here and I need to read up on it - but I ran across this - https://www.mtsu.edu/gem/index.php

The goal that I am thinking of is to not fully power the bus like an EV, but have hub motors help it get going, be able to use the hub motors in regenerative braking (thinking of long mountain downhills...) and to utilize the a couple of Leaf or tesla type battery banks to draw power from when parked.

Thoughts?

[Sehnsucht]

Hey! That's my old screen name! There's been some developments since 2016. Tesla is an all-electric solution but I'm still partial to a hybrid solution. Tesla's semi prototype is reported to use 4 of the hub motors from their cars, one in each drive wheel, to provide adequate torque. The concern I have is battery requirements to keep up with stop and go traffic. A hybrid diesel-electric configuration seems likes a better option so that a smaller internal combustion engine turns a generator and battery capacity (weight) needs only satisfy the short-term demands. If you want to add battery capacity for comfort/convenience loads while parked that may be a worthwhile weight penalty but unnecessary if you use energy wisely.

[BlackHeart]

Yeah, there have been some great advancements since 2016 - and yet, no one is really converting.
With what was going on in that article I posted,you could possibly add something to your existing hub and brake drum. Like a permanent magnet motor.
But I haven't been able to get a hold of the professor in charge.

[Ronnie]

Must my in my dreams a Tesla semi power package( batteries, motors and electronics) would be great... but cost where to recharge as you can only use Tesla's chargers if you buy the car/truck. Hybrid is more doable, using a generator to charge the batteries, and still having the Tesla motors and batteries. but a lot of cost and not to sure it would have enough gain. Stop and go traffic, school bus route or any driving that regen braking gives back. However highway driving which is most of our skoolie driving minimal fuel mileage gain. Here in Virginia electric buses are already being used by some schools. Wait till they get retired and add a generator.

[Sehnsucht]

RE the article BlackHeart references and the video link, I'm just not sure how practical any type of retrofit kit will ultimately prove and it seems far more likely to me that if electric vehicles become the de facto standard then internal combustion will simply fade into the sunset as infrastructure converts and upkeep becomes cost prohibitive for the average personal vehicle owner. If conversion is an avenue, I think this is simply a more likely candidate:

https://spectrum.ieee.org/cars-that-...ny-classic-car

And it even looks like a small block V-8! It seems to rely on existing drivetrain so if you still have a transmission then you don't need a very large motor and smaller motor means lower battery consumption. However, by keeping the transmission and conventional drivetrain you haven't reduced the weight much so then that's a tik back on power requirements. So it's a balancing act.

In the school bus world there have been a few (very few it seems) advances in electric and hybrid technology but as these buses are essentially built in semi/heavy truck technology and that industry hasn't fully embraced either method of electrification, the amount of R&D being poured into electric school buses is surprisingly little, probably just enough to produce a few prototypes for schools in communities with deep pockets and progressive policies towards environmental responsibility. So many are more likely cash strapped so don't want to spend twice as much per bus for an unproven technology which they can't even fit themselves.

[Gorm Auslander]

I'll be watching this thread with interest. The lack of research is understandable, as the technology is still very expensive. I wanted to go full electric, but back of the napkin calculations had me around $30,000 for a Tesla-powered 100kwh battery pack (just the battery pack), and that might get you 200 miles of range all-electric. Possible? Yes. Practical? Hardly. Your next challenge is stashing 20 5kw battery modules around your build, which you can do with creative planning, but that's weight budget and space lost.

The hybrid idea seems more favorable as far as expense and power density. My 2 cents backed by zero experience is to not bother decoupling the engine and making it a generator, but upping your alternator game and throwing an electric motor into the power train somewhere, like unto a prius. You lose engine power, but you gain electric power which can assist, so it balances out.

[cadillackid]

having the motor coupled to the drivetrain all the time.. or at least a lot of the time seems to be where on my hybrid car i get lots of gains.. the regen braking.. my hyundai hybrid controls the regen braking and mixes it with mecahnical braking if needbe.. if you sto,p the brake pedal hard then you have a full physical link to the brakes and overrides any computer control.. but the regen part.. I can see a lot of energy being put back into the battery from it.. I can drive that car, get home and my brake discs are barely even warm..



the other piece is cutting out the idling... the gas engine is off and EV mode engages when I let off the pedal.. the engine also decouples so there is no drag from anything more than regen braking if im coasting down or on the brake pedal...



now credit to modern (HEUI at least) diesels like the DT466E, cat 3126, T444E.. is that those engines do "shut off" when you are in coast down the injector pulsewidth goes to 0.. but of course when you get slowed down they restart to an idle.. and they have drag the whole time on decel..



if you could have something that created regen braking, and then had electric A/C, lights, etc, or even charged your house batteries (if you normally alternator charged them).. you could make some gains.. if you could make a way for the engine to completely stop at lights etc.. even a smewhat small "trolling motor" just to get you rolling where you could engage the diesel engine then.. my T444E uses on average 1/2 gallon per hour (closer to .7 with A/C on) to sit and idle..



the biggest issue with being on the road and large batteries.. is you use it up every day or two how are you going to charge it.. its one thing to build an IMA "integrated motor assist ) (Honda hybrid) type system where an electric motor can give you assist.. but you have to have enough solar to top the batteries off.. 100kwh battery takes a lot of solar to charge it back up...


you for sure dont want to end up either having to generator charge or public EV charger ($$$$ per kwh at public charger)..



you do have the benefit that any solar you have on the roof of your bus is likely to work very well while you travel during the day.. full sun exposure on most roads and lots of air around the panels helping to cool them.. but you have that benefit now.. to be able to charge your house batteries up and / or run electric A/C while driving if you can get enough of it in there to keep you cool..


electric motors can also ne used to help keep your engine in its happy spot.. my hybrid car does this.. the engine is not big or powerful.. it has a power band and RPM band where its most fuel efficient (all engines do).


your diesel is no different.. many people on these forums swapping transmissions, tires, rear end gears etc to try and put our engines in their "happy spots"..



one of the biggest complaints from owners of small econo-cars (and why many of them have disappered in the USA).. is that the car "doesnt have enough power to get out of its own way".. pulling into traffic, freeway ramps etc.. and these cars get horrible mileage when you push em hard..



enter a hybrid.. electric motors give you that torque to take off without spiking the engine... they also come on with the engine when hitting freeway ramps or needing to pass cars.. the result is a car that has the driveability of a model with a much bigger engine..



in a bus climbing a mountain you could keep your engine closer to its happy place and let the slectric motor generate torque.. on the other side regen braking couldreally help to keep your brakes cool (and charge the battery)...


just brainstorming.. the reality of actually building this as a DIY is pretty advanced (though i think id enjoy building the computer control and software for it)..

[Gorm Auslander]

Originally Posted by cadillackid

the biggest issue with being on the road and large batteries.. is you use it up every day or two how are you going to charge it.. its one thing to build an IMA "integrated motor assist ) (Honda hybrid) type system where an electric motor can give you assist.. but you have to have enough solar to top the batteries off.. 100kwh battery takes a lot of solar to charge it back up...


you for sure dont want to end up either having to generator charge or public EV charger ($$$$ per kwh at public charger)..

Charging at superchargers may cost more than home-grown electricity, but it's so vastly cheaper than diesel I doubt anyone's complaining. In a heartbeat I would take the convenience of an established network rather than worry about the fact that I had to spend a whole $25 to fill up my tank rather than $500

As for solar, I was about to agree with you in it's function being solely to run house appliances rather than charging the battery, but I found a gentleman able to install 1.7kw of solar on his bus, which is enough to charge 100kwh battery after about 60 hours of full operation. Obviously no solar panel operates at full power, but you could park this hypothetical EV bus over a week in a scenic location and leave with a full charge. A bus is actually the ideal vehicle for solar powered operation because of it's surface area.

[cadillackid]

Originally Posted by Gorm Auslander

Charging at superchargers may cost more than home-grown electricity, but it's so vastly cheaper than diesel I doubt anyone's complaining. In a heartbeat I would take the convenience of an established network rather than worry about the fact that I had to spend a whole $20 to drive the next few hundred miles rather than $500.

As for solar, I was about to agree with you in it's function being solely to run house appliances rather than charging the battery, but I found a gentleman able to install 1.7kw of solar on his bus, which is enough to charge 100kwh battery after about 60 hours of full operation. Obviously no solar panel operates at full power, but you could park this hypothetical EV bus over a week in a scenic location and leave with a full charge. A bus is actually the ideal vehicle for solar powered operation because of it's surface area.

of course if you are parked in full sun for extended periods you can charge the traction batteries.. however most people want to park in shade and reduce the amount of A/C required to keep the bus cool.. obviously if you are at a high elevation in spring or fall then you may want the extra sun heat and then being in clear air works out great to charge everything.. but it seems like a lot of the travelling goes on in summer.. at least for those making RV's.. full timers obviously have a myriad of different lifestyles..



but noi my point about solar was mainly for the idea of those on a trip who are going to be driving every day or two vs long periods of parking..



charging at a supercharger isnt going to happen very easily as somehow your on-baord gear would have to mimick a tesla and not get caught by surveillance as another vehicle type.. oh and physically fit!


a regular EV charger most ties is a paltry L2.. though more and more DCQC are popping up at public locations.. and of course the number of public chargers is only going to increase from here on out so finding them isnt going to be an issue.. at least not in a few years..



when I had my chevy volt back in 2012/2013 timeframe I had it easy.. hardly anyone had a plugin and govt grants for free chargers were everywhere.. that car got about 40-50 miles depending on how cold it was out so many times driving around town I didnt pay for "fuel" for weeks at a time....

[Gorm Auslander]

lol nice. That would be swell.

Word on the wind is that the Tesla network will be opening up to regular EVs later this year or next in the USA, and it's already started in the EU. Regardless, you make an excellent point that a 40 footer sticking out of a charge spot could draw some attention

[DeMac]

(1905 Electric 5th Avenue Coach)

(1908 Fifth Avenue Coach)

(1909 Fifth Avenue Coach)

Electric & gas/electric hybrid buses are actually a century old. In fact, Roland Conklin and his brother Stanley financed & operated Conklin Brothers’ Gas-Electric Motorbus Corporation, Roland Gas-Electric Motorbus Co. and American Motor Bus Co.

Most of their trucks & buses were propelled by Percy K. Hexter's design of the Hexter Gas-Electric drivetrain.




(1913 hexter gas-electric)

A General Electric variable speed electric motor directly driving (shaft or chain) the axles. The electric motor was powered by an inboard gas generator.

It provided zero jerk start & stops and excellent downhill control. Offering much lower operating costs than gas, steam or horse driven. At the time, a superior product, with several hundred used in public transport throughout NYC, Chicago, & London.


Roland also converted a bus to a Motorhome in 1915

[Veloc]

Keeping up with the electro-Joneses is one of my other things. The Cybertruck has a ginormous physical footprint, and the charging sites are set up for a Cybertruck with a trailer, so a bus will fit. And, there are a large number of companies springing up whose whole mission is to use wrecked Teslas to convert gassers into EVs, either as a turnkey setup or as a crate kit. Still pretty pricey, but they're working out on how to defeat the Tesla electronics. If Tesla supercharger networks are released for other makes, and Tesla will need to do this if they want to control charging (where the real money will be) by forcing all manufacturers to copy their charging connections (and pay a nice royalty per unit) then it won't be an issue to eventually convert a bus from diesel to all electric and have access to fast charging. Existing Tesla large motors already make the necessary power to move a bus as they're running some 600HP and 700TQ ratings (not exact numbers but close) so a pair of them can handle a bus no problem. They can also be synced so you could mount one to each rear wheel and have no connection between them. Syncing electric motors to run the same speed has been a thing for decades, and the syncing can be controlled to allow for one side to go faster than the other during turns. Anyone wanting to make the conversion, the pieces are all there, it's just a matter of putting them together now.

[cadillackid]

electricity has been widely used in traction for years like you mention.. electric busses still run in dayton ohio.. and most downtown trains in cities are electric.. albeit they are on shore power .. rail powered but the idea of going and stopping with electric motors is not new..


self containing a hybrid.. my hybrid car gets 55 real-world MPG (overall).. its not a plugin.. its just a "limited" model hyundai elantra.. while it doesnt have tesla style summonable self driving.. the car will actually drive itself in stop N go traffic.. its impressive ...



anyway the regular model elantra real world overall is around 35 MPG...



you figure in the case of this car its small (1.9 kwh) battery is charged by the engine and by regen braking.. nothing else.. there are times in slow drive situations around town it will be in full EV mode for a couple miles...



it also has the ability to run in EV mode on the freeway at hoghway speeds when the conditions warrant for it..



in the cases the car is full EV I feel the engine de-couple completely..

the air conditioner and the water pump are electric.. admittedly my MPGs go down quite a bit in cold weather because the only means of heat is engine hat.. it doesnt have a heat-pump.. (and i like the car WARM!.. as in no coat on onside even in winter)....



so my MPGs drop to about 48-50.. (lower on short trips where the engine has to idle alot to get an initial warm-up)..


but anyway the ability to couple and de-couple the electric motor from the engine seems to be somewhat key..



the original honda hybrids from what I understand never could run completely in "EV".. the engine and motor were always coupled and those cars still got close to 50.. however a Prius C (stripped down model) that came out in like 2010 was getting 60 pretty easily..as they had figured out how to run EV even at highway speed by then..



so yeah if you want ot build an elaborate drivetrain you can put together a system that operates like a modern hybrid car... bigger the battery the more versatility you have..

[magnakansas]

here is my future plan for my 1954,

sits on a 2005 f450 chassis

engine via a 6 six speed manual is connected to the rear axle.

IF I install a front driven axle

add a drive shaft... I dont want the weight of the electric drive going up and down with the suspension.

There is someone out there that builds a driveshaft flange that plugs into the drive splines on a rear tesla electric drive... so you turn the tesla unit 90 degrees and align it with the pinion yoke on the front drive axle.

This lets you connect a drive shaft and bypass the differential gears... you couple the drive shaft flange to the ring gear by engaging both side gears of the differential at the same time.

now you can use the front axle for braking by using the drive motor as a retarder. thus charging the batteries too. you can use the battery pack as a house battery too.

in poor weather you can run on front drive only... snow, ice, low grip conditions. In town, stop and go driving, you can run on the 250 hp front drive only....

In the hills the extra 250 hp would help to get up the hills without slowing down so much.

The turbo charger can be sized so that it might be soggy on the start and stop side of engine rpm and the electric drive can make up for the turbo lag.

That brings me to variable geometry turbos with mechanical engines..... I see this as a very good thing, but there is no development work being done with this. bummer.

Electric hybrid turbos.... also very cool new tech for mechanical turbos... But no developement going on ... bummer.

The very time consuming part-- the software needed to integrate with the internal combustion engine driveline is going to be very time consuming to make work "seemlessly" I think one guy working on this .. once all the mechanical part is done... I would not be shocked to see a five to ten year development.

This can be done.

william