Concept: Plug-In Hybrid Drive Retrofit for Heavy-Duty Trucks

www.greencarcongress.com ^ | 11/13/2007 | Staff

[Red Badger]

A pair of Australian inventors have developed a concept for a retrofitted electric drive unit to convert conventional heavy-duty transport vehicles to plug-in hybrids.

The retrofit concept uses a bogie axle drive to create a through-the-road hybrid drive that can reduce fuel consumption up to 25%, by the inventors’s estimates.

This would fast track the introduction of hybrid vehicles onto our roads by utilizing the existing fleet...We expect the conversion unit to pay for itself in the first year of use by way of the reduced fuel consumption. We have secured a patent pending to entice investors so as to start producing this concept. —Clifford Hall

Main components in the conversion. One mode of conversion is to reverse the positions front to back of a typical two-axle bogie drive unit and to discard the connecting jack shaft. This allows the installation of two electric motors to the former front-drive axle (now in the rear), utilizing the power divider unit.

Converting trucks with a single drive axle and a trailing, non-drive load sharing axle would require either the purchase of another single drive axle to replace the lazy axle or the purchase of a bogie front-drive axle to replicate the other mode of conversion with twin electric motors.

The Halls use UQM HPM150 brushless PM motor/generators for reference. The UQM units offers 150 kW (200 hp) power peak, with peak torque of 650 Nm (480 lb-ft). The inventors envision using a combination of lithium-ion batteries and supercapacitors for optimum performance. The Li-ion pack will be grid-chargeable.

Proposed modes of operation for the hybrid vehicles include:

*

Truck leaves terminal with fully grid-charged batteries. *

Acceleration using combination diesel and electric assistance. *

Highway cruising using diesel only and cruise control. *

Hill climbing, cruise control engages electric assistance to maintain road speed. Diesel rpms and throttle position remain static. *

Down hill, regenerative braking slows the vehicle and recharges the batteries. Diesel engine rpms remain low, no over revving. Braking also recharges batteries and saves brake wear. *

Quiet mode, electric assist is engaged to maintain road speed while diesel engine only idles. It is for travelling slowly through towns to reduce noise pollution.

A working prototype has not yet been built.

[Red Badger]

Rest In Peace, old friend, your work is finished.....

If you want ON or OFF the DIESEL ”KnOcK” LIST just FReepmail me.....

This is a fairly HIGH VOLUME ping list on some days.....

[Red Badger]

KnOcK!!!!!!!!!............

[Attention Surplus Disorder]

Although I welcome any provably functional concept along these lines, it seems like you’d have to have some screaming powerful motors on the drive axle; MUCH bigger than pictured. A 50 hp elec motor is already about the size of an axle differential. Somehow I doubt that 100 hp could pull a loaded semi truck. Maybe on some runs in Oz where there are fewer hills, but I don’t see it having enough power/torque.

[Vn_survivor_67-68]

I remember from a Hot Rod magazine in 1963 or so an axle-mounted turbo-type impeller coupled directly to the axle.....it just idled with axle power, but for drag-strip use, the chump/customer was to put a rocket-engine type dry canister of fuel on the housing, which applied its force to the impeller, igniting it with a switch on the dash whenever the “racer” wanted the boost. I don’t think many were sold as I never saw one or ever read anything more except advertisements for a few succeeding the original “article” which was probably paid for in addition to the regular ads that appeared.

[taxcontrol]

Yeah that was my first reaction ... 450 ft/lbs is weak for a tractor rig but might work for flat running. I wonder if it could be used like a brake and then recharge the batteries?

[mwilli20]

A working prototype has not yet been built.

And you know why? Because it would not work! And to make it work they must make it uneconomical. How do I know? Because car and truck companies are in the business of making MONEY! If this made any sense to any consumer out there it would have been in production a long time ago.

People have been making electric cars since the 1830's and hybrids since 1901. It's not their time yet so... KnOcK it off already! ;-)

[Attention Surplus Disorder]

Well, on re-reading the motor specs, if they are to be believed, they seem quite powerful. Liquid nitro cooled and all, LOL. I’d like to see a prototype working in the 110 degree Aussie outback.

[AZLiberty]

It’s a hybrid. The electric motor only has to assist. Presumably it would only do all-electric on flat land, would use electric assist when going up hills, and recover energy going downhill. How may horsepower do you need to keep a big rig at steady speed on horizontal terrain?

[Squantos]

Thanks for the ping RB !!

[AZLiberty]

“may” —> “many”

[Red Badger]

The UQM units offers 150 kW (200 hp) power peak, with peak torque of 650 Nm (480 lb-ft).

[Red Badger]

Apparently the electric is used for “In TOWN” and the diesel for highway. The electric kicks in for “maintaining cruise control” at grades.................

[Red Badger]

It’s not a totally electric drive. The Electric is for assist on grades and acceleration, and allows the diesel to idle in slow traffic............

[FreePaul]

...Liquid nitro cooled and all...

Liquid nitro is readily available without expending any energy to produce, isn't it? Well, maybe not but doesn't this just add to the mystery?

I'm sure they just need a large government grant to get started on this. Surely our representatives will vote for this appropriation since it's "green."

I'm going to wait until they get this kind of thing to 110% efficiency. Then the energy they have left over will be cheap.

[DustyMoment]

Talk is cheap. Prove the concept and I might buy it.

[Attention Surplus Disorder]

If you read the thing carefully, it would appear that the only thing(s) they have worked out are the axle brackets for the uber-motors, LOL. Still.....one of these days, someone will come up with a whiz-bang that will achieve something in the direction of the desired energy-saving end. I so very seriously doubt it will be two guys in a garage, however. Except for internet companies, it would appear those days are over.

[Deaf Smith]

"Liquid nitro cooled"

I can see a problem with transferring engineering specs from one country to another and by language.

In the USA, Nitro does not mean Nitrogen and they are not interchangeable terms.

The economies of scale better dictate the use of electric drive wheels as demonstrated in the Mining Industry with their super large trucks and diggers.

[19th LA Inf]

R.G. LeTourneau was a prolific inventor much like Tesla. He developed a drive system for heavy earth moving equipment which employed AC motors in the wheel hubs, back around the time of WW 2 as I recall. I think he sold the system to Westinghouse or GE. In those days, diesel locomotives depended on DC drive motors, but I believe now they have gone to AC systems also, using the diesel to generate onboard AC power. But it doesn't seem that AC would be suitable for hybrids, as the losses from converting DC battery power to AC would be too great.

I would think that liquid cooling for DC motors would permit quite a bit more horsepower per pound to be delivered, as the only apparent limit is what temperature the insulation can stand. DC powered drag racing cars and motorcycles can show amazing performance for the few seconds it takes to make a quarter mile run. The batteries might be the limiting factor once the motors are given a cooling system.

[Deaf Smith]

Keep in mind there is a reason US road trucks need large engines with 9,13 or 15 speed transmission/differentials (two speed differentials).

[chuckles]

They are already working on a hydraulic motor hybrid with a pump, accumulator, hydraulic motor setup. It is used in UPS type delivery trucks. It has the advantage of unlimited torque, no batteries, and less maintenance and cost.

Just "Google" "hydraulic hybrid", for the latest pics.