I was thinking today..and i wondered..why don't they make an electric car,with a generator that goes on one of the wheels,or perhaps,a generator running off of each wheel,that works like a battery charger,and recharges the electric battery's as you drive...so the only electricity you'd really be using would be to start the car,and up to a certain mph...just an idea..but seems like it should work to me...just a thought out of my crazy head..

 

Any gains would be minimal because of math and physics. It's my understanding that you cannot create energy, only convert it from one form to another. In this case, the energy expended (the effort required to drive the "wheel generators") may actually exceed the energy produced (to charge the batteries). A device that produces an equal or greater amount of energy than it consumes in the process is called (I believe) a "perpetual motion machine". Our science tells us that it's impossible.

Any smart people out there that can confirm or correct me on this?

 

Guess you're not the only one who thought of this?
http://www.tech-m4.com/eng/tm4transp...to_wheelmotor/

I saw an article (forget where) that had a compact truck (S10?) with two of these motors replacing the entire rear diff and it made more power than the stock 4 banger.

 

Unfortunatly my dreams were dashed too when I went to college and learned about the laws of physics. I thought about putting a large pully on a motor and a small one on a generator, lets say with a ratio of 2:1. My idea was that the generator would generate twice the current used by the motor and the extra would go to storage, and the work load back to the motor to continue the cycle. But friction and heat loss got in the way of my brilliant idea. I'm still a poor struggling engineer. Keep thinking and someday you can come up with the next big thing.

PS. warp drive has already been thought of but not perfected.

 

Okay, for it to work you just need the right electric motor. There are a few made that WILL recharge the batteries while coasting. The way they work is when power in not applied the weight and speed of the vehicle cause the motors to turn into gennies, and recharge the batteries. They are mostly used on hybrids with a gas motor assist. I think the better thing to work on is a water engine. One that can actually burn water........

 

I think Homer Simpson said it best- "Lisa, in this house we obey the Laws of Thermodynamics." Perpetual Motion is a hard thing to come by.

 

nicely said invirocon

 

Ford is already doing something similar to this with the Escape Hybrid. The heat from braking is converted to energy that re-charges the batteries. Which is why the Hybird gets better mileage in the city than the highway. Ford had some New Yorkers drive a Hybrid to work recently using the most congested streets in NYC. The FWD Hybrid achieved 36.5 MPG. Not bad, as long as you live in the city (why am I suddenly thinking of that salsa commercial: "NOOO YAWK CEEETEEE!!")

 

saw a nice idea to use the braking of the vehicle to run a
hydraulic pump and pressurize a tank.
when the vehicle accelerates they use the pressure to
run the pump backwards and assist.

 

That hydraulic accumulator idea is being tested on garbage trucks.

 

thanks for all the replys everyone...wow..that site was great Triton...it says that each one of those have a 107hp output and 494 LB OF TORQUE!!!..imagine one of those on each corner...wow...talk about moving!..

 

I read once where someone was developing a bus that had a large flywheel that kept spinning when the bus was stopped. The idea was the the energy in the flywheel would be used to get the bus moving, saving fuel.

The Escape Hybrid does a great job of capturing energy from braking that would normally be lost as heat and uses it to recharge the batteries.

My brilliant idea as an aspiring engineer was to mount a windmill of some sort to a vehicle, using the air movement to charge batteries that would propel the car. Again, the laws physics and thermodynamics gets in the way - the additional drag on the vehicle, combined with the inefficiency of the generator, would still result in a net loss of energy.

Some laws just can't be broken....

 

Sorry to say that today's technology won't allow us to build the perpetual motion machine. However, it is important to have people continue to think it IS possible, and to work toward these impossible inventions. I salute all of you that not only work on creating, but those of you that will keep asking these questions! Think where we would be if our predecessors had been satisfied with the status quo.......

 

They have used flywheel driven buses in Europe for years- Switzerland, I think. You could help the batteries out by covering the car with solar panels. I don't think you could capture ALL your power from the sun, but it would cut down on charging.

 

Most hybrid and electric cars use "regenerative" braking as a means of conserving energy. In a traditional friction brake system, all of the kinetic energy the vehicle has while moving gets converted to heat and then lost to the surrounding air. In energy terms, this is wasteful.

In a regenerative braking system, the drive motor is used as a generator when braking. The kinetic energy is converted back to electricity and stored in batteries. The magnetic "drag" on the generator effectively brakes the vehicle. When it is time to accelerate again, the stored energy is used to drive the electric motor.

In a purely electric car, regenerative braking helps extend the range on a single charge because energy isn't wasted when braking.

In a hybrid, regenerative braking improves fuel mileage: a smaller engine is used and the electrical system is essentially there to capture the kinetic energy while braking and provide an acceleration "boost" due to the extra power (torque, actually) from the electric motor.

"Flywheel" vehicles are either purely electric vehicles or hybrid vehicles. The flywheel is just the mechanical equivalent of a battery. Lead-acid batteries are not that efficient as an energy storage device, and they are heavy. Nickel-metal-hydride and lithium batteries are more efficient, but also considerably more expensive and less long-lived. The flywheel would be heavy and spun at high speed so it can store a lot of kinetic energy. An article I read in Popular Mechanics or Popular Science many years ago mentioned that the flywheels would run in a vacuum to reduce air drag losses, and use magnetic bearings to reduce mechanical losses.

The flywheels are not mechanically coupled to the drive wheels of the vehicle. There is an electric motor/generator attached to the flywheel. During acceleration the mechanical inertia of the flywheel generates electricity which is supplied to the motors attached to the drive wheels of the vehicle. The flywheel slows down, but the vehicle speeds up. During braking the electricity that comes from regenerative braking is used to spin the flywheel back up to speed.

In a hybrid flywheel vehicle, a small gas engine is used to make up for the mechanical and electrical losses of the system, and aerodynamic drag. IIRC, there was a simple flywheel-electric delivery vehicle sold in France in the 80's - the 3-wheel 'tuk-tuk' or something similar. The idea was to spin up to speed at the home base, make local deliveries and get home again before things ground to a halt. I think the hybrid is a better idea...

Cheers,
Eric