With an electric set up as described you are basically trading a fuel tank for a battery. You can run the fuel tank to lower levels to save weight and allow the helicopter to do more work. A battery weighs the same if it is fully charged or empty so you would have the weight penalty of a full tank of fuel no matter where you go.

Max

Just an Idea....
 

Hello everyone
Electric seems to be full of advantages.
But I propose yet another technology.

Magnetic Motor

This video is an example of a magnetic motor of the simplest there is.

But if you have time to see one or two more videos it's better to understand the technology.



Already there are more ideas on how to maximize this energy and believe me, there's more to come.

Engineers can do anything if they want. (If they are allowed!)

If you adjust that supply power to the helicopter. we do not need more fuel or batteries.

just an idea ...





:)

There probably aren't any weight savings in the hybrid configuration.

But you would eliminate gearboxes and all the headaches that come with that. You would eliminate the whole anti-torque shaft, head and actuation. You could do startups in no time etc. And it would be much more reliable as electric motors pretty much never wear unless the bearing goes.

The fossil fuel debate is interesting. However, even though your electricity might be fossil fuel based (not always, but likely) it makes much more sense to ship all the fuel to a power station, than to truck it out to every nook and cranny of the world to fill it up into aircrafts. The infrastructure of electric delivery is already there, it's paid for and available pretty much everywhere. You can refuel anywhere. Obviously as electric cars are already becoming quite the reality, I'm sure there will be some kind of "refueling" standard in place for them. Perhaps aviation could use the same connectors and infrastructure?

Didn't they say that about cars back in the 1900's?

It's taken a while, but for cars it's def happening now. You just have to see how much the Prius has sold worldwide. And how every manufacturer is scrambling to get electric or hybrid cars out on the market.

Aviation might take a bit longer, but I'm personally 100% certain it will happen in my lifetime.

And Tazzz, that seems like yet another version of the elusive perpetuum mobile. It hasn't worked in the last 500 years and will never work as long as Newton is in control.

But a turbine takes very little time to start in any case. A large percentage of start time for a twin engined EMS helicopter these days comes from waiting for the avionics to come on line, not its turbine engines.

I reckon that most people reading this thread have already flown an electric helicopter. I actually owned my own a few years back! Okay, so it was a scale model co-axial helicopter with a little remote control but still it proves it is feasible.

I guess what is needed is a substantial amount of investment from our industry. However, considering a hell of a lot of helicopters are sold to service the oil industry to extract fossil fuels I'm doubtful that helicopter companies will be pouring money into R&D!

As an aside lets hope electric helicopters don't fly into walls like mine seemed to have a habit of doing!!

PT

I'm pretty sure that making an electrically driven helicopter with a turbine would make a lot of sense, seeing as how it's a lot more reliable and definitely less finicky then a gearbox. Lithium based batteries that can get the APU online to get the main turbines online, that would power rotors via electrical power has sort of been done before, and proposed for vehicles like tanks, that also have a lot of weight spent on the drivetrain.

I'm not so sure that separating the tail rotor from the main rotor is such a good idea.
What if something happens to one of the engines?

Sorry Adam, but IMO this is nonsense.

All the energy in this system is initially coming from the APU to charge the battery, so you may as well drive the rotors from the APU and save the battery and electric motor weight.

But it is much worse than that. There are significant energy losses in the electric generator and then the electric motor, so the fuel efficiency overall is much worse than a plain ol' turbine.

When batteries are good enough for a one hour flight, and they are ground charged from a non polluting electric power source such as solar, hydro or nuclear, then it all becomes worthwhile.

As for the Prius - it's a gimmick. You will get better overall efficiency in the *real world* out of a small modern turbo-diesel.

As that 'taken a while' has been about about 100 years, I'll wager a fiver on that last sentence ;)

The idea was to charge the battery from the ground and have to APU just keep it topped up. Only in a remote area where no electricity could be found, would the APU be running to charge the battery up.

Pretty much like the Chevy Volt that comes out now.

Yes, there are energy losses, but so are there in gearboxes. I have a hunch the APU and Gen will weigh less than a gearbox, but I could be wrong.

This is true. However, may I make a direct comparison to the field I work in - Cinematography.

All these new HD cameras and digital stills cameras have come along and pretty much put film still cameras out of business. Most of you probably have an old film camera laying around in your house, but you shoot on your digital cameras these days. Film cameras for the motion picture industry is still hanging on, but their days are numbered. Now, do any of these HD or still cameras resolve more pixels than film or actually look better? No they don't. In fact, the latest HD cameras have far less resolution than film has. I can easily extract 6K information from a 35mm film frame, whereas an HD camera barely manages 2K, and that's heavily compressed. Yet they've completely taken over. Why? Because it's good enough and convenient.

Now, would you rather not have a little bit less range in your helicopter, if you could virtually eliminate TBO's on drive components? If you could tenfold reliability? If you could fly for half the cost? I think most business and individuals would be happy to make that trade. And that's where I think electric cars, aircraft, whatever will live in the beginning. It's an interesting future, for sure.

No!

Pilot:

"Sorry Boss, we can't get to the destination for your important business meeting....battery's run flat. That's it for today. I'll get you a taxi and I'll try to get the aircraft recharged overnight. I'll come back for you tomorrow and do the same again... Look on the bright side, we have more TBO on the drive components!"

Boss: "You're fired!"

Adam, helicopters need more range and endurance, not less!!

Got it in one!! :ok:

What about a hybrid? Electric-powered tail rotors, but the main rotors will continue to be driven by the turbine? No more complex drive shaft, more power to the main rotors, reduction in weight etc...

Or alternatively...
"Sorry Boss, we can't get to the destination for your important business meeting... Aircraft in for maintenance again. That's it for this week or two.
I'll get you a taxi and I'll try to get another aircraft hired in. Then in another 50 hrs we do it all again".

Boss: : "We're stuffed"

A week or two for a 50 hour? :eek: Find another aircraft type, or another maintenance organisation!

Hybrid chickens = Good.

Hybrid helicopters = No thanks.

1) How is a high power generator, remote electric motor (heavy!), power regulation system (probably including huge buffer capacitors to deal with sudden load changes) less complex OR lighter than a driveshaft and a 90deg gearbox?

2) Why would such a system provide more power to the main rotor?
The electric tail rotor still needs the same power as a normal one. The method of getting it there would be way less efficient than with a simple driveshaft.
So, less power available to the MR, and more weight.

A breaktrough where one could develop a generator or alternator capable of recharging the bats while you are airborne.:ok::ok:

that would be the mystery solver :E

and we only have 50 more years left of oil in the world... so we need to come up w/ something fast!:eek:

Unless you've been an R/C flyer in the last 10 years and seen the revolution there, I don't think everyone here understands just how light and efficient modern brushless motors are.

I can buy and off the shelf 20hp brushless motor that weighs 2,5kg (5lbs)!

Hacker A200-6 Motor - HAA2006

With even more exotic materials in the housing, that could probably be made even lighter. No drive shaft, tail rotor assembly or linkage is ever going to be lighter than that.

Just as a thought experiment: an R22 probably needs, what, 10-15% of the power to power the tail rotor in its most extreme condition? That's roughly just about 20hp. So this itty bitty brushless would be able to that job. Cost less, vibrate less, weigh less and be more reliable.

And since they are so light, you can overpower the tail rotor. Let's say you stick a 30hp motor in the example above - much more than what's needed in normal conditions. This will give you an extra margin of safety and maybe avoid a LTE situation. It's there if you need it. Unless the battery is flat, that is;)

Says who?

Oil reserves are plentiful, says Aramco chief | IBTimes

Just another fallacy like global warming!

Did you know that there are billions of barrels still completely untapped here in the US, Canada, Russia, Indonesia and Africa!

Nice day man!

HM

I own a model helicopter with a Brushless motor, and I still don't believe it.

That motor only replaces the TR gearbox. The TR gearbox of an R22 is pretty light, i doubt it weighs more than 2kg.
You still need the power regulator, cables, and mainly - a 15kW generator and some decent size buffer batteries.
Not to mention that the motor, like all brushless motors of comparable size/performance i have heard of, runs at high RPM. So you would still need a 3:1 reduction GB.

The TR thrust in helos is limited through the pitch angle of the blades to protect the drivetrain, the TR itself and the tailboom. If one wanted a stronger tailrotor, these components need to be made stronger. That problem doesnt change with an electric one, except you'd need to beef up the motor and generator instead of the drivetrain.

A lot of books say up to 30%. I don't know though.

I think lot of RC flyers see the amazing performance they can get out of electric RC helos, and underestimate the problem of scalability.

YEAH! Right!

You are gonna believe in some rich saudi bizz man with his legs tied to oil companies stocks that just writes an article out of nowhere...:ok:

And you think the Americans will let the ''untapped'' oil be tapped after what just happened in the gulf? := Don't think so.

And don't forget about China, India and Brazil were they are booming and starving for more and more oil after each year.

The future of electric power in VTOL craft is more than the simple replacement of a gas engine with an electric motor.

It is about the ability to provide unique enhancements, which today's reciprocating and turbine drives cannot provide.


Dave

Another issue with this proposal is that you would get lag in your anti-torque control. Direct drive tail rotors work on small model helicopters because the tail rotor has so little inertia it can change speed really quickly and you don't get any control lag. On an R22 sized helicopter, I imagine there would be a noticable lag and on a significantly larger helicopter, I can imagine it would be difficult to control.

Another issue is that with vibration and fatigue. One of the reasons that helicopters are designed with a specific main rotor and tail rotor RPM is that it makes it a lot easier to do the vibration analysis and ensure the helicopter doesn't have any nasty resonances at the operating RRPM.

Deemar
The speed does not change. The electric tail rotor would be at a constant rpm with collective pitch.

cattletruck, you're right. It may be a race to see if effective electrical storage or a cure for cancer comes first.


Regarding an all-electric tail rotor, The current project involves the application of a torque-pitch coupling to a pair of small electrically driven main-rotors ~ Electrotor - SloMo. This feature should be applicable to a tail-rotor, also.

When the pilot increases the power to a rotor the torque reacts before the speed does. This increase in torque causes the collective pitch to automatically increase, then as the speed increases the torque and the collective pitch partially reduce.

Dave

hybrid Vs purebred
 

Interesting debate lads. While its true that some breakthrough in battery technology is needed to get anywhere range wise with a purist all electric chopper today, the technology is improving at 9% per year which means that batteries will be half the size for the same energy storage in just a decade even without a game changer.
Re hybrids. The auto industry have tweaked that's it's easier to move energy over wires than drive shafts, the Lexus RX400h has an all electric rear transaxle for example. A turbine (or two) running a poly phase alternator with wires to all electric MRB/TRB direct drives with minimal or no batteries is not science fiction as a concept.

The future of the helicopter is electric, limited only by the length of the power cord:cool:

Dave,

I think you should revisit that explanation :hmm:

So the collective pitch automatically increases as a result of increased torque: what sort of helicopter are you talking about?

Squeaks

A governed, gyro stabilized electric (fly by wire) tail rotor would do just that.

An electric tail rotor should be safer too. For example you could have the ability to switch it off in flight if for example you had a "jammed pedal"
In fact why don't they do that now, without waiting for the all electric helicopter to come along?

Just came across this
 

Havent really had time to look every little thing up but first impression.. Very cool. We are lucky we have these stubborn scientists and engineers.

Im gonna look this stuff up a bit closer but its looks promising indeed..

Squeaks,

The specific Torque-Pitch Coupling does not exist in current helicopters. It is an innovation that is intended to simplify the pilot's control of very light recreational helicopters. The micro-light Electrotor project is an ideal testbed for implementing and playing with this idea; due to its low cost, the incorporation of other ideas, and the ability to initially fly it as a large R/C helicopter.


This is a revisit to the explanation, but it is a long and boring one. http://www.unicopter.com/Wink.gif
DESIGN: Electrotor-SloMo - Control - Flight - Auto-Collective by Torque-Pitch Coupling - Overview
OTHER: Rotor Concept - Flight Control - Torque/Pitch Collective Rotor Hub


Dave

World’s First Manned Electric Helicopter takes off
 

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The World’s first manned flight of a 100% electric powered helicopter was conducted on the 12th of August 2011, after 2 weeks of tethered flight tests. This machine, designed and test flown by Pascal Chretien, for the French based company Solution F, is the outcome of a remarkably short development period that was initiated in August 2010.

This ultra light coaxial helicopter weighs 170-Kg empty, including 60 Kg of high performance air-cooled Li-ion polymer batteries that can deliver 43 KW continuous, and 52 KW peak. The craft weighs 247-Kg at takeoff and offers 10 to 12 minutes flight time. To save weight, conventional cyclic and flight controls were replaced by a weight shifting system, as well as a specific design for rotor inertia, and blade pitch. Collective and yaw are achieved via electrical flight controls.

An advanced MOSFET based feather light drive train offers astounding 87.5% end to end efficiency, from batteries terminals to rotor mast.

This helicopter is a demonstrator intended to pave the way for hybrid rotary wing aircraft and is a test bed for new technologies. Flight envelope expansion is ongoing.

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http://www.electrotor.com/Temporary/...GE 1 Small.jpg

http://www.electrotor.com/Temporary/...GE 2 Small.jpg

http://www.electrotor.com/Temporary/...ed 1 Small.jpg

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Dave

Dont know that I'd want to be sitting on 60kg of Li-Po batteries!

Hmmm... I wonder if that's why they put it into a ventillated protective box?