rotary engine -- what's the name ??

Recently I spoke to the Engineering Manager of a company which
manufactures rotary engines for aircraft. I mentioned to him that I
read about a "rotary" engine which is a kind of Wankel engine, but has
two paddles in the shape "X". He told me that the name of such a type
of engine is "nu-teddy" because of the crossed paddles. I did a search
on the Internet, but could not find any mentioning of "nu-teddy".
Obviously, I wrongly spelled it. Maybe someone can tell me what was
the term ? Thanks.
Reply to
Beladi Nasralla
Loading thread data ...
I read about a rotary engine called something like "nu-teddy". But I can't find any mention of "nu-teddy" on the Internet. If I misspelled it, can someone can tell me the correct term? _______________________________________________
Nutating.
Reply to
Rodan
"Nutating" (oscillating), I think. If it's the one I'm thinking of, its the McMaster Motor. There is only one "paddle". The brother of a guy I worked with at 3M invented it and he used to show us its progress at our monthly retirement breakfast meetings. the brother is now gone, but the commercialization continues. Last I heard, they had a large order from a cab company in England.
You can see it at >
formatting link
Pete Stanaitis ----------------
Beladi Nasralla wrote:
Reply to
spaco
BTW in relation to aircraft, "rotary" also means a radial in which the crankcase rotates, & the crankshaft is stationary. See Gnome Monosoupape (ie 1-valve), and similar designs. Popular in WW1, but long gone now.
Reply to
David R Brooks
The McMaster (wobble) motor website causes me to pause when I read hyperbole like this: "Each power stroke results in very smooth, high torque, equivalent to an eight-cylinder engine." The Technical Information portion of the website consists of 3 paragraphs and the website looks like it was last updated in 2000. I suspect that one of of many significant technical issues to be solved will be designing seals for the wobbling rotor.
The idea has been around for quite a while and the latest spin is to make it run on hydrogen. Count this as yet another automotive version of vaporware.
Reply to
John S.
When I saw the comment about hydrogen I guessed that the engine is such a stinking polluter that hydrogen is the only thing that could get it passed the law.
It sure is interesting though. If somebody could just come up with clever geometry like that without having reciprocating, sliding seals. This isn't the first engine with that problem. It was solved pretty well in the Wankel but Renault's wobbly engine never did get it solved.
-- Ed Huntress
Reply to
Ed Huntress
According to the website the motor is the centerpiece of a project involving "A new engine; A new fuel source; A new source of power to assist in the production of the fuel". The company address is at a University and they were apparently looking for funding from a variety of sources including a DOE grant. Ultimately their goal appears to be money from licensing production: "It is anticipated the McMaster Motor's technology will be licensed to multiple industry sources for volume production."
I don't know if this is going beyond the dream stage.
Reply to
John S.
There's an article about it here:
formatting link
and this discusses real world concerns such as seals and coatings:
formatting link
I guess I'd like to see more about it if it is as promising as the NASA article implies... --Glenn Lyford
Reply to
glyford
Rotary engines were used in aircraft long ago. While they were powerful little motors they had several problems which limited their use.
Just to confuse things modern-day Rotary engines of Wankel design have been used in aircraft although not widely.
Reply to
John S.
here:
formatting link
coatings:
formatting link
Well, yes, but websites that trumpet the 10 most important benefits of a given product but say nothing on the downside do not strike me as unbiased. Indeed I start thinking about sales hype.
There have been several promising engine designs over the years that have come forth only to die a slow death. One I remember was a resurrection of the old Sterling Motor to run a generator/battery driven electric car. Seals were the biggest problem. The motor would run fine until the loud pop told of a broken seal, exploded hydrogen and rapidly declining mph.
I'm sure the problems of that design could have been fixed but the costs of doing so would have been considerable. The result mwas likely not a marketable product because of the development cost.
Reply to
John S.
I guess I wasn't clear. Is there a company that currently manufactures a rotary engine specifically for aviation use?
Reply to
Jim Stewart
Among real companies are: Mistral Engines UAV Ltd Possibly Wankel AG (not sure of their current status--Wankel Gmbh went under and Wankel AG is the remains under new management)
Moeller Skycar has an engine manufacturing subsidiary, but like all things Moeller, one should believe it when they deliver a product to you personally.
Reply to
J. Clarke
If you look at it the right way, any turbojet/turbofan/turboprop is a rotary engine. Probably more efficient than anything using a non- continuous combustion cycle. Don't know of any other type approved for aircraft use. I think it was the BD-5 that was designed to use a Wankel snowmobile engine and there were some small model-sized Wankel glow-plug engines, don't know of anything else recently that's actually flown and isn't a magnet for venture capital and/or government research contracts, e.g. vaporware.
Stan
Reply to
stans4
Actually Teledyne Continental has licenced the Norton Rotary engine, and Avco Lycoming, in concert with Deere and Co are also working on a rotary engine concept. (or have been in the last 15 years - no idea at what stage they are today)
Reply to
clare at snyder.on.ca
Turbojet/turbofan/turboprops also unless you luck into military surplus cost a mint.
There are numerous homebuilt aircraft flying with rotary engines. Here's a list of some that are flying or near completion
formatting link
Most are based on the Mazda 13-B. The things seem to be robust the same way that WWII radials were robust.
Reply to
J. Clarke
Hey Jim,
You are correct. There are still rotary engined aircraft flying today, but few and far between, and none are new. I also do not believe that there are any new rotary engines produced, but there are still many new and varied radial engines in full production today. With the exception of "model engines" of course. The model engineering engines come in two basic flavours...scaled sizes of prototypes, and a large variety of custom designed. There are always a couple of each at NAMES, some even run in the demo area.
The "rotary" engine referred to in other posts are Wankels (mostly RX-7, 13-B's), and to me these are rotory rather rotary.
Rotary engines rotate the cylinders and hold firm the crank, so the cylinders spin.
Rotory engines are those as in Wankel products, where they use a rotor with a shaft for output, rather than conventional pistons and crank.
And then there is the Rotax line of engines, which are much used in Ultra-light aircraft, but are neither rotary or rotory nor radial. Just conventional air cooled recips.
Take care.
Brian Lawson, Bothwell, Ontario.
Reply to
Brian Lawson

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.