Turbine powered mopeds

The next big leap in internal combusion engines for the mass market will probably be turbine powered electrical generators powering electrically propelled vehicles including mopeds. The technology is in wide use today; and because of advances in electronics any wheel can be redesigned into an electric motorwheel which also serves as a brake/generator. Just think - no pistons to waste energy, with most braking energy converted to electricity to charge a battery. I think Volvo has a car/wagon slated for production using this technology which will be released very soon.

Re: Turbine powered mopeds

Turbine powered cars were tried out in the 1960's and while their engine could last hundreds of thousands of miles, they were hardly efficient. The turbine has to spin at a single speed for most of it's operation, somewhere around 20,000 rpm's if I remember correctly. Also they are huge and are never going to fit on a moped.

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I've seen one that's small enough, but it'd be a waste concerning efficiency. Turbines are great small power packs, but they suck fuel and are usually used for locations where power required offsets their healthy appetite for jet fuel, like airplanes.

If you own a jet bike, you're rich, or need to be. They are simplistic in operation, but far from that concerning manufacturing. Things that spin at 20-50,000 RPM need special attention during manufacturing. Not something a chinese sweat shop can deal with. Probably could buy quite alot of mopeds and gas for the price of an inconel burner can or compressor blade. Although, I have heard of people converting turbo chargers into crude engines, which are far less efficient than an engine designed specifically for the job.

However, I do like the idea of gas electrics. I wonder if anyone has ever taken those 300watt electric motors off of ebay and ran them with a 2 stroke connected to a 12v dc generator?

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When energy is converted from mechanical to electrical, energy is wasted. So, using a gas motor to power an electric motor to drive the vehicle is just a waste of energy.

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Yeah, chains are pretty efficient. The best apps for gas/diesil elctrics is when it's hard to reach the driven devise, especially in tight locations such as locomotive trucks and some boats where transfering energy to said device are, or would be next to impossible to connect mechanically without severe losses.

I'd still like to see a gas electric bicycle even if it is wasteful, but then agian, I like steam engines too.

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Long Distance Tripper /

Think 2008 Finny .. 45 years later .. and the technology leap is astounding.

Re: Turbine powered mopeds

Long Distance Tripper /

I think you'll be surprised at what's around technology wise.

I think a turbine-generator combo suitable for mopeds would be the size of the cylinder without the head in a normal 50 cc engine .. the motor being the wheel.

Re: Turbine powered mopeds

Long Distance Tripper /

No chain would be nearly as efficient as a direct drive wheel motor which operates with the magnets running around the rim. These things drive trains.

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"When energy is converted from mechanical to electrical, energy is wasted. So, using a gas motor to power an electric motor to drive the vehicle is just a waste of energy."

Remember We're also converting mechanical to electircal, back to mechanical. So the loss would be even greater. But you're making an assumption that the original method of production is as inefficient as the internal combustion engine. So your ending efficiency may be greater

Are we talking standard gas turbines? or tesla boundry effect turbines? in theory, tesla's design is by far more effcient, but you gotta take that with more then a few grains of salt, because almost everything tesla did later in life was "magical".

I'd love to see someone build a woodgas moped, but hell the chambers would be twice the size of the moped.

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Thanks Jack - after looking at your websites I would say the turbine-generator combo would be 1/4 the size of the cylinder on conventional 50 cc engines .. the 'engine' being the magnets running around the rim of the wheel, conductor properly placed, or the rim being the magnets .. wow, what a weight loss in propulsion system.

Re: Turbine powered mopeds

I have to disagree, Berg, because so much energy is wasted in a conventional piston engine with the piston going 'up down back forth in and out angle angle flex flex every which way' .. and a conventional 4 stroke loses energy in valves while the 2 stroke loses it in suction. Think of air-powered airplane models - those things do amazing things with a few pumps of an airpump. Almost no turbine energy would be needed to drive the generator, especially as a battery pack would provide initial momentum with the generator carrying on and also recharging, and recharging through brake energy. Energy lost in driving the magnet rim would be next to nothing. I wish I was an engineer, I'd patent this moped.

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I just had another thought about weight saving. The gearbox, chain, sprockets would be eliminated so Wow that weight could be put into a SUPER battery .. and with two phase electronics we would still have a high and low speed ..

with three phase we could have three speeds. This just gets better and better .. except for repairs on the roadside. Spare electronics I guess.

Re: Turbine powered mopeds

Railroads have been doing it for years.

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Bah! The efficiency of turbines is abysmal thought they do operate well withe steam power. The Tesla one would be almost impossible to make with modern technology though we are getting closer. The alternative you want to play with is Stirling. 30% efficient and very simple. I always figured you could put a heat collector in your seat and have an "Ass Powered" bike, only you might get really cold riding it. Other more practical options: Use exhaust pressure to power your turbine, then run a Stirling engine off your engine heat which is pure waste. These two devices will charge your battery allowing you to switch between gasoline and electricity.

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How about this: Brushless motor(50%-70% efficiency for lowend models, and 70%-85% efficency for highend models) coupled with a high capacity lipo battery(getting cheaper everyday) and you have yourself a light weight, torquey electric moped that is virtually zero matinence and the battery is enviromentally friendly. Joe

Re: Turbine powered mopeds

Better idea: rotary powered mopeds. Check out the Aixro XR50 engine, 50cc rotary, 50hp, weights 36lbs.

Too bad a new one is >$5000, if I had the money I would love to put that onto a moped frame.

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thats tight,

i still dont think you'll beat a mid 70's european moped engine for the job no matter what. they got it right back in the day, thats why i still ride a moped.

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Wow, can we complicate a moped even farther? I believe that one of the reasons we like these things so much is that they are so simple. Maybe not super efficient on a cylinder to whatever basis, but extremely cost effective to get the job done. Even if a turbine engine was super efficient, it still costs a bundle and probably will for some time to come.

However, it is still fun to think about all of this.

BTW, Tesla's turbine does work (Tesla's claimed efficiencies have not been confirmed) and can be built with today's tech. He had problems back then when no-one had made hi-temp metals that were strong enough to stay together at high RPM and temperature. The catch is; the only people trying to do something with his design are shadetree machinists and tinkerers without the clout and money of say GE or Pratt & Whitney. I would love to see a truely working model because the design is stupidly simple.

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The poor mechanical-to-electrical-to-mechanical efficiency point is a good one, but it's true that there is a huge gain in transmission efficiency.

With any hybrid gas/electric vehicle, the gas motor can be tuned to run at peak power and efficiency, and the electric motor can run without a transmission to put out power at any speed.

Power band all the time - every start is a neutral-drop.

Thinking about it makes you inevitably dream of a perpetual motion ped, but there is merit to the idea.

That said, I wouldn't expect any hybrid motorbike small enough to lift any time soon. That rotary engine rocks, though; I want one.

Re: Turbine powered mopeds

Sachs has had one for years

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Wiffle's been doing some thinking.

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On a moped that engine would last until the fire falls.

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Tesla was a genius, that's for sure.

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haha

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Re: Turbine powered mopeds

Brendan Chenelle /

hahahah awweeesome.

I built a small pulse jet, but that thing is a full out turbine.

I wonder how he maintains oil pressure, what he uses for fuel, etc..

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