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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."
This engine was developed primarily by people at the University of Calgary, not SAIT. He only teaches at SAIT, they didn't have much at all to do with the development of the engine as far as I can see.
Anyway, it's an interesting piece of technology.
Random and weird software I've written.
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).
Get paid to code OSS
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.
The masses are the crack whores of religion.
Some internal combustion engines use gears instead of chains/belts so it isn't always an issue.
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.
Comments should be like skirts. Short enough to keep your attention, but long enough to cover the subject
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=
- 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. 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.
Scientists restrict study to entire physical universe; creationist
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.
Nope. Read the white paper. It describes the compression and expansion clearly. Here's the process:
Advantages:
Disadvantages:
Overall, this is one of the more promising alternative designs that I have seen.