Here is a possibility of a one rotor going into mass production. This
could be good!

Tom/norpro

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Rotary Engine Finally Could Find Home in Future Hybrids
By David E. Zoia
WardsAuto.com, Jul 16, 2010 9:00 AM     Email a link to this
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ANN ARBOR, MI ? The rotary engine may have a future after all.

Once thought to be the next big thing in automotive powertrains,
the rotary, or Wankel, engine largely was shelved by developers
in the late 1970s, a victim of toughening emissions standards
and rising fuel-economy demands.

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Nearly every major auto maker seemed to have a rotary in the
works during the decade, but Mazda Motor Corp. was alone in
putting one into volume production during that era and is the
sole producer of a Wankel-powered car at present, the RX-8.

But the rotary may have new life, ironically as a result of the
industry?s push into vehicle electrification.

Gary Hunter, chief technologist-diesel engines for AVL
Powertrain Engineering Inc., says the rotary may find a home in
future extended-range electric vehicles, similar to General
Motors Co.?s upcoming Chevrolet Volt.

EREVs run on electricity, but use a small internal-combustion
engine as an electrical generator once stored battery power
begins to run low.

Speaking to a University of Michigan Transportation Research
Institute conference here on future powertrain technology,
Hunter says the rotary offers a packaging advantage over a
conventional piston engine in such applications.


Speaking to a University of Michigan Transportation Research
Institute conference here on future powertrain technology,
Hunter says the rotary offers a packaging advantage over a
conventional piston engine in such applications.
AVL?s rotary hybrid powertrain.

Enlarge Photo

?The nice thing about piston engines is everybody has them, but
piston engines are too large,? Hunter says.

A 0.57L 2-cyl. piston engine producing the same amount of power
as a 0.25L rotary not only would be bulkier but weigh 24 lbs.
(11 kg) more, he says.

To prove its point, AVL has cobbled together an EREV based on
BMW AG?s Mini Cooper, using a rotary engine to keep the battery
charged.

AVL?s powertrain group built the rotary, Hunter tells Ward?s,
though it is seeking to license production, not actually
manufacture the engine itself.

?We built it only for demonstration purposes,? he says. ?Now
we?ve been successful in that, so the next step in the
development phase will be to find someone to manufacture it.?

Component production is ?not AVL?s business model,? he adds. ?We
design and develop; we don?t manufacture.?

The AVL single-piston rotary engine displaces 0.254L and weighs
64 lbs. (29 kg), including the starter/generator. Combined with
the power electronics, cooling circuit for the electronics and
core unit to connect to the vehicle?s cooling system, the setup
weighs 143 lbs. (65 kg) and measures 19.2 ins. (49.0 cm) long,
38.6 ins. (98.0 cm) wide and 15.7 ins. (40.0 cm) high.
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The unit generates 15 kW of electric power at 5,000 rpm, but can
be scaled up to 25 kW at 7,000 rpm. A slightly bigger version of
the rotary engine, displacing 0.357L, can produce 36 kW at 7,000
rpm, while a double-rotor engine could deliver 50 kW.


The Mini test vehicle uses a 10 kWh lithium-ion battery and can
travel 19 miles (30 km) on a single charge. With its 2.6-gallon
(10L) fuel tank and 15-kW rotary, range is extended to at least
124 miles (200 km), AVL says in a technical paper. It gets to 62
mph (100 km/h) from a dead stop in 12 seconds.

Hunter says auto makers are intrigued by the hybrid concept, and
some component manufacturers have expressed interest in building
the rotary engine under license, though he declines to be
specific.

J. Gary Smyth, executive director-North American Science Labs
for GM, says the near-term future of vehicle electrification is
going to come down to ?battery-electric vehicles vs.
extended-range electric vehicles,? such as the Volt and AVL
concept.

While favoring EREVs like the Volt overall, he admits it will
take time to determine whether they meet consumer needs better
than BEVs.

?The Volt?s early volume is not an issue,? he says when asked
how many GM expects to sell. ?The real issue is how
range-extended vehicles will play out (longer term).?

Michael Omotoso, senior manager-global powertrain forecasting at
J.D. Power and Associates, says sales of all hybrids in the U.S.
should total 315,000 units this year, accounting for 2.7% of the
light-vehicle market. Penetration should grow to 9% in 2015, he
predicts.

dzoia@wardsauto.com

==============================================================
I don't see this or any other range extended vehicle as viable.
What happens when the battery is dead and you have an over weight
car due to batteries, generators and motors with only a 25KW (33 HP) engine?
It will be a dog when it comes to passing on a 2 lane road
or climbing hills. Especially at  5000  to 10,000 feet
in Colorado.

The solution is to improve the BSFC of the rotary using turbo
compound keeping the drive train weight down and the power to
weight ratio high for passing and climbing hills.

IMHO the Volt will flop.

It will make a nice APU for motor homes.

Paul Lamar

Paul

Yep.  Forget about hybrids unless your motor is on a trailer you
can leave home for short trips.   BTW this was the original
concept used with the Tesla for going across country.  Others
have done it with sawed off motorcycles.

There is a market however for remote village electrification
and a compact robust Wankle powering a generator might be the key.


Doug in Japan

I always thought that trailer was an ingenuous solution :)

Way back with the GM electric (60 mile range)  I help test for
Pop Sci I suggested a Honda generator in the trunk to get you home.
The Nethercutt museum has one of the last GM EV's not crushed by GM :)
http://nethercuttcollection.org/

Paul Lamar