New Super Efficient Rotary Engine

[Yetii]

That rotor is completely different than the Mazda Wankel. Interesting!

[med]

They are probably trying to get the end seals to work. Same issue as with the Wankel.

The cycle does look clever and potentially has some fuel savings - but I imagine they will loose a fair bit of that due to the friction on the seals.

[zboss]

Originally Posted by Cormorant

Here's a bit from LiquidPiston's web page, describing their history. As with other promising technology (graphene-based watermakers!), I wonder what's taking so long. If they have patents protecting their inventions, and have working prototypes, it seems they could license the tech to many various manufacturers and change the world. I suppose they're just working out all the bugs and optimizing things, while locking down any remaining intellectual property before going big.

About Us | LiquidPiston
History

2015

Developing the power-dense, near-zero vibration, quiet X Mini, 70cc gasoline powered rotary four-stroke engine.
2012

Built working, firing 70 and 40 HP diesel engines, model “X,” that demonstrated the capability of engine architecture and thermodynamic cycle
2011

Invented and designed a new engine architecture, model "X," that embodies the HEHC cycle
2010

Built firing 20 HP diesel engine prototype, and what may be the world’s first naturally-aspirated rotary diesel engine
2007

Received small business innovation research (SBIR) grant from Army
Received first venture funding. Key investors include: Northwater Capital and Adams Capital Management
2004

Awarded top three winner prize in MIT’s entrepreneurship business plan competition (now called the $100K entrepreneurship competition)
2003

Dr. Nikolay Shkolnik and Dr. Alexander Shkolnik invented the innovative HEHC thermodynamic cycle and initial engine designs that embody the cycle

Usually these guys are doing their startups as second jobs. Also, patent searches and applications take a long long time and are very expensive.

Originally Posted by med

They are probably trying to get the end seals to work. Same issue as with the Wankel.

The cycle does look clever and potentially has some fuel savings - but I imagine they will loose a fair bit of that due to the friction on the seals.

I misreported that there are no seals... apparently the seals held in place using a different mechanism than the wankel.

"Where the rotor holds the seals in a normal Wankel, the housing does that job in the X1 engine."

[bobg3723]

Just looking at it the only thing it's lovely gut's has in common with a wankel rotary engine, it seems, is that their designs utilize eccentric rotors, albeit a novel oval rotor with a tri-lobed housing as opposed to the the familiar Mazda engine variety. Now that's thinking outside the limitations (dead end?) of the Wankel. If only Tesla Motors could appropriate this. Can you imagine one of these driving a generator coupled to a Powerwall running E-drives. Cool shoes!

[cabo_sailor]

Does anyone remember the Suzuki rotary engine from the '70s? On their motorcycles?


Sent from my iPhone using Quantum Entagelment

[hellosailor]

Sure, anyone remember the miracle Chrysler Turbine Engines from the 1964 World's Fair?


Never quite revolutionized anything, did they?


After someone puts a couple of thousand cars on the road for five years in mixed real world use...or a couple of thousand outboards, whatever...then it is time to talk about how revolutionary a new technology might be.


Till then? The folks who can't make it to Vegas, can do their homework and decide whether to get rich investing. Unless the odds are better in Vegas.

[henryv]

I believe the Ecomotors people with their OPOC engine will be in production this year so their smaller more efficient engine should be on the market soon.

Sent from my SM-P900 using Cruisers Sailing Forum mobile app

[nimblemotors]

Small rotary engines are already made for airplanes/drones.
Someone in England makes them for go carts also.
They don't seem to last very long.

[leftbrainstuff]

The rotary concept suffers from poor thermal efficiency of the combustion chamber. Emissions killed them off for mass market.

They are more of an inertial engine. Lots of revs and no torque.

The split cycle engine was an interesting variant that allowed for a long dwell which meant the exhaust cooled and was therefore quiet. I did some of the early build and bench testing of a variant back in the early 90s.

Rockwell bought the licence for a stealth jeep. It then went nowhere.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[bobg3723]

Maybe my referring to Wankel's as being a "dead end" was a bit vague. But it had it's run as a production gasoline automobile engine but was not competitive for the masses. It's a fine performer within it's niche market in the aerospace sector, but this new rotary can eclipse even that sector with a lightweight, small form factor, small frontal area engine that can also run diesel. Now if some bright enterprising British lads can market a gas wankel rotary to the para-sailing crowd, I wouldn't be surprised if an enterprising licensee would do the same with a diesel powered rotary prop spinner and that hopefully can cross over to genset application where diesel power has earned it's status as the fuel of choice.

Sadly, I'm still waiting for my Mr. Fusion on backorder from Doc Brown.

[med]

Do they have a solution for the end seal?

That was always a problem for rotary engines and I have not seen anything new there. So while the cylinder design is interesting and doubtless brings some advantages, the main problem still remains.

[bobg3723]

Originally Posted by med

Do they have a solution for the end seal?

That was always a problem for rotary engines and I have not seen anything new there. So while the cylinder design is interesting and doubtless brings some advantages, the main problem still remains.

A 2014 technical paper addresses that issue for aviation drone specific applications.

A Heat Pipe Assisted Air-Cooled Rotary Wankel Engine for Improved Durability, Power and Efficiency

[newhaul]

I wouldn't actually say the large wankel market is exactly dead Mazda was still producing them for cars as late as the 2012 model year in the rx8 and they say if theycould sell 100 k units a year they would continue to produce it. This new liquid piston setup builds on wankels research I'm hoping for a small light diesel genset in the 3k range for my boat. Light and portable.

[med]

Originally Posted by bobg3723

A 2014 technical paper addresses that issue for aviation drone specific applications.

A Heat Pipe Assisted Air-Cooled Rotary Wankel Engine for Improved Durability, Power and Efficiency

No mention about end seals in there.

[newhaul]

Originally Posted by med

No mention about end seals in there.

The paper implies that the seals would last much longer due to reduced wear at lower temperatures quote from the paper " Our heat spreaders would not change the frontal area of the engine and should have a negligible impact on the installed weight of the propulsion assembly. We expect our approach could lead to a very significant reduction in thermal stress-induced warping which is primarily responsible for wear and high friction. With reduced friction and wear, the thermal efficiency of the rotary engine is increased, and the durability of the engine would be improved very significantly at the same time. "
Mazda uses ceramic lip seals to increase the wear longevity aspect