New rotary engine design

This one uses an oval rotor in an epitrochoidal housing:

http://www.wired.com/2014/11/tiny-engine-make-leaf-blowers-sound-less-like-jet-engines/

I'd love that in a chainsaw.

That's pretty cool

I just came across this company the other day too. They've also got 40hp and 70hp diesel versions, in addition to the latest 5hp gas version. If it actually lives up to their claims, this could be a great step forward.

So, who actually thinks leaf blowers sound anything like jet engines? That is a stupid headline, but a pretty cool little engine.

It very much depends on how efficient it ends up being.

That, and if they can re-design the lawn equipment so that they are able to use that kind of output shaft speed. (and I'll ignore the noise issue, as it should be able to deal with that)

Interesting that they chose to use a fuel/oil mix, since that fuel is slowly losing it's favor due to the emissions two strokes produce. It would be MORE of a game changer if they had a gas only 4 stroke version- as it would easily replace millions of small engines.

it will be interesting to see this progress.

do want

I don't care how efficient it is as long as my hands don't go numb from it vibrating like a bastid like the boingers do.

In reply to alfadriver:

While it is a 4 stroke engine, wankels still need oil injection to lubricate the seals. No real way of getting around that thus far.

It might be more convenient to have a separate oil injection system, like people often set up on automotive rotaries. No need to premix fuel or worry if it's premixed correctly, just keep the oil injection tank topped up.

alfadriver wrote: It very much depends on how efficient it ends up being. That, and if they can re-design the lawn equipment so that they are able to use that kind of output shaft speed. (and I'll ignore the noise issue, as it should be able to deal with that)

15K rpm?

the hotest saws around now do 9K to 12K... so it's impossible..

Find a way to put some sort of oil injectors and an OMP and the fuel oil mix could easily be overcome. Very interesting, can't wait to see on something like a snowmobile.

JtspellS wrote: Very interesting, can't wait to see on something like a snowmobile.

YES, a return to the 70's!!!! https://www.youtube.com/watch?v=QFLL3_mtwa0

In reply to Fueled by Caffeine:

It's not supposed to be a hot saw. It's supposded to be a weed trimmer. Or a hedge trimmer. Or a blower. One that will be ok in neighborhoods not the back woods or a competition.

In reply to yamaha:

They implied that it uses a standard pre mix. I don't think rotaries use that much oil.

It would be interesting to see the emmissions from it relative to the goals.

alfadriver wrote: In reply to Fueled by Caffeine: It's not supposed to be a hot saw. It's supposded to be a weed trimmer. Or a hedge trimmer. Or a blower. One that will be ok in neighborhoods not the back woods or a competition.

Time to add a turbo then.

A rotary chainsaw has been done before. You can see the problem in the gif thingy, the flame front is huge and there is a huge quench surface between the rotor and housing. I don't know much about rotaries but they are neato. Old man wankel designed an engine for mercedes but the gas crunch killed it.

GameboyRMH wrote: This one uses an oval rotor in an epitrochoidal housing: http://www.wired.com/2014/11/tiny-engine-make-leaf-blowers-sound-less-like-jet-engines/

You guys missed the main point. It's not that it is a small rotary engine. We've had those for years. It's that it is an OVAL rotor. Which I'm sure means no apex seals. Thank god someone figured that out.

In reply to alfadriver:

I haven't read their technical papers or patents yet to really get a better grasp of what they're doing, but remember that this is also just a development engine to see how well the technology scales up and down from their larger diesel engines. Why would they complicate it any more than necessary either? There is nothing saying that their further developments would have to do likewise. I don't believe that any of their development engines have had cooling systems yet, but they would probably develop that too.

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In reply to Trackmouse:

It has seals, but they are mounted to the housing rather than the rotor. And it's not just different from a Wankel style rotary engine in that it uses and oval rotor rather than a triangle, but it's actually operating on a completely different thermodynamic cycle than anything else we're used to as well.

The Instagram algorithm served this up to me and I couldn't believe that GRM hasn't discussed this yet. A search led me to this old post.

Looks like this company got a big investment from DOD and continues to develop this inverted Wankel design. Pretty fascinating. 
 

https://invest.liquidpiston.com

They are used in portable generators. Small, compact, light, can run on a variety of fuels.

Mazda has announced a rotary range extender in their new electric car, that might be more fun to play with

I had some very minor involvement with how to configure an EFI system for them. Glad to see they're still making progress; this is one of those engines that seems like an interesting idea but one where I'm not sure what obstacles they may be up against getting it developed to the same level as piston engines.