Toroidal Engine Ready for Production

FarceMajeur writes "Business 2.0 has a column on a recently prototyped "round engine," properly named a toroidal engine, by VGT Technologies, Inc. Nice Flash animations of the concept are here. I've always admired the Wankel engine, but it seemed more like a time bomb than a going concern. This engine is billed as the 'world's first practical Concentric Positive Displacement Engine,' meaning no eccentric rotation to generate vibration, meaning fewer catostophic failures, one would hope."

Comments

Yet another revolutionary internal combustion eng

[HotNeedleOfInquiry]

My understanding is that there is something like 500 different designs for internal combustion engines. Needless to say, nearly all of them are useless for one reason or another.

Reciprocating pistons and poppet valves still live because they work well, can be manufactured with simple operations and have seals (piston rings and valve seats) that will last for years.

I thought about a design like this many years ago and concluded that there would be major difficulties sealing in the combustion gases. I guess time will tell whether the problem has been solved.

Timing

[lirkbald]

Well, I looked at the animations. Neat idea, I think. But what happens if that timing belt goes? It looks to me like the thing would smash itself to pieces.

What would happen if a timing belt gave out on a 'normal' cylinder-based engine? I'm not too knowledgable about engines, but it doesn't seem like it would be quite as catastrophic.

Re:Timing

[Beatbyte]

timing belt on a piston based engine goes bad, your timing goes way off and the engine won't be functional until its replaced.

that does seem to be a huge problem with this engine's design. it may be a timing chain (less prone to failure) on these engines though.

rotary is the best engine design when it comes to failures, but is also not very efficient and seems to have been dropped by everyone (basically mazda).

Re:Timing

[oyenstikker]

What happens when the timing belt goes on your reciprocating piston engine falls into one of two scenarios. If you have a "non-interference" engine, the valves stop moving in proper relation to the piston, your air, fuel, and exhaust just goes wherever it can, and the engine stops. You probably only need a new belt and to get the timing reset. If you have an "interference" engine, the valves will run into the piston. This can have catestrophic affects. Such as valves getting pushed right up through the head, and possibly even right through the hood. Then you're lucky if you only need new pistons, new valves, and a new head. But you're probably not lucky.

Re:Timing

[FrostyWheaton]

But what happens if that timing belt goes?

It depends....

The timing belt/chain keeps the valves opening and closing in sync with the turning of the crankshaft. If that belt fails the valves will cease to move.

In some (most?) enginges the valves do not travel past the highest point of travel of the piston at any time. In this case, all that will happen is the engine will cease working and need to have the timing belt/chain replaces.

However if there is no clearance between the top of the piston's travel and the bottom of the valves travel (as in come higher performance engines) you will have catastrophic failure of some sort as the pistons collide with the valves. Repairs for this type of failure will be huge.

To return to the topic: Failure of the timing belt in this engine would be very nasty. The rotating "piston" would collide directly with the auxilliary wheel most likely fusing the two together if not ejecting the smaller wheel from the engine. Either way, it would be niether pretty or repairable.

Re:Timing

[Rip!ey]

Timing belt failures are bad on regular engines too.

Not always. As a mechanic by trade, I can offer the following...

It actually comes down to how they designed the engine. Generally, an overhead valve engine is either free-running, or it is not. If it is free running, then the pistons can rise to top dead center without contacting any valve which is fully open. This is, as already stated, by design. In this case, a cam belt breakage will still leave you stranded, but the cost of repair will be limited to the cost of a timing belt replacement. If an engine is not free running, then yes, repairs will be very costly indeed.

In my experience, when a timing belt breaks it usually means the owner didn't replace it when they should have. It's amazing how small savings now can cost more in the long run.

I'm taking the don'ts

[Paradise Pete]

Mr. Pekau is an experienced mechanical engineer....In addition to Mr. Pekau's work, which is well documented

IANAE, but this is likely to be a crackpot/scam venture.

The phrasing I've quoted above, which come from the web site, are big red flags. They're trying to pitch Pekau instead of the engine. Along the lines of "he's really smart and knows what he's doing, so of course his engine works." This is how scam after scam after scam gets pitched. "Ignore all the nay-sayers, because they just don't understand what our guy has done."

The phrase "which is well-documented" is also a tip off. Nobody says that unless it's not quite true.

Re:I'm taking the don'ts

[JUSTONEMORELATTE]

IAAE, and while I have no basis from which to say "this is likely to be a scam" I can certainly say that the site does NOT give me any kind of confidence that the concept works.
They have a prototype, but only one picture of it.
They have a video of the prototype in some sort of testing facility, but the sound is intermittent, the video cuts from scene to scene for no apparent reason, and there isn't ever a shot OF THE ENGINE actually running. Think "alien autopsy" but not as credible.

Tell you what, guys. If you've got a WORKING PROTOTYPE of a revolutionary (no pun intended) internal combustion engine, and if you've already applied for the patents, then why not spend an hour producing a decent video of your invention in action?
As they say, extra-ordinary claims require extra-ordinary proof.

--

Re:Ok, I'm confused...

[Smidge204]

Ah.

No, the second wheel is not being hit by the main wheel. That would be bad. The taper on the "wings" is to provide an offset. (The wings act as valves - blocking off ports in the top and bottom of the engine body.)

The "vertical" wheel is driven by a gear and belt system from the "horizontal" wheel. I would've thought all the threads about timing belts/chains would have tipped it off, if you somehow managed to not notice the huge belt and pulley assembly on the sife of the engine in those 3D models.

There doesn't have to be a flywheel. The inertial mass of the components provides that function.
=Smidge=

Useless because of technical hurdles

[Spamalamadingdong]

Rather than moderate, I decided to comment.

No they are not useless from a technical POW. One of the alternative designs should be used if we had to redesign all of engines, factories, fuels, motor oil and car's form factors.

Bull puckey. The choice of engine is at least somewhat independent of the choice of fuel; for instance, a spark-ignition piston engine will burn the same fuel as a spark-igniton Wankel, a diesel will burn anything that will ignite easily enough, and a Stirling or gas turbine can run on just about anything that burns, period. Fuels include:

• light and medium petroleum distillates;
• petroleum byproducts such as propane;
• methane (fossil or biogenic);
• vegetable oils and derivatives such as biodiesel;
• heavy petroleum fractions;
• wood, wood gas and charcoal;
• coal.

For any one of those fuels, I can cite an example of one of the above families of engines running on it. If an engine isn't being widely used, it's because it's difficult to manufacture or requires expensive materials. Right now we are using the least-expensive (and thus most cost-efficient) technology we've got, and that's the right thing to do.

The design we use now is not the best one, it just happens to be the one whole automobile industry is shaped around.

In a word, hogwash. There are a host of different engine designs around, and some of them have even achieved some presence in the marketplace. Examples:

• Wankels
• Stirlings
• Gas turbines

We don't use the Wankel because it has too much chamber surface area per unit displacement, causing heat losses to be greater than a piston engine and losing the efficiency race. We don't use Stirlings because they are external-combustion engines requiring very high temperatures to be efficient, and the materials for the hot-side heat exchangers are not cheap. We don't use gas turbines because they require (again) heat exchangers to be most efficient, and (for vehicles) nobody's come up with a design which isn't either too bulky or loses too much efficiency to leakage; for road vehicles, turbines remain the province of superchargers, not the main power producers.

A lot of research money has been expended on these engines in the past. Superior technologies do win out, just as fuel injection has displaced carburetors from all US production cars. If you can come up with a way to beat the technical problems which prevent any one of these engines from being manufactured as cheaply as a piston engine while meeting the same efficiency, emissions, noise etc. requirements, the world will beat a path to your door.

The main problem...

[Muerte23]

Is the precise timing required by the whole system. You see the vertical wheel with the notch? That notch has to pass the little wings on the rotor exactly on two sliding surfaces.

Those tight fit parts that absolutely fly by each other have to meet, slide, and keep a pretty good seal. Each time the timing chain is a little off, say to increase or decrease in power, they will miss a little, bonk, and get worn. Hot exhaust gasses slipping through will probably cause preignition in the little transfer tube. Nasty.

Also notice how much physical distance the compression arms of the rotor have to move each cycle. Can you imagine the heat from friction and the lubrication required? And the kinds of seals that you would need? I guess you could get decent lubrication by using the rotor as some sort of centrifugal oil pump, but still the wear would be nasty.

Consider as well that it's basically a 2 cylinder 4-stroke engine. It's gotta be a pretty good size and run at a pretty high RPM to get enough power to be really useful.

Don't count on this one.