Reply With QuoteYou cannot "use the spin of the wheel to make more energy". You cannot create energy! No matter where you put the alternator, eventually your prime mover must supply the energy. Look at your total energy balance.
Timelord
Hello, I have been wondering for a while about why car manufactures don't just put alternators in the wheels on cars, For example if you have an electric car with battery's in it once you've used the battery's to get the car moving then the alternators use the spin of the wheel to make more energy (Only alternators on the non-drive wheels) which then is put strait back to the main motor. I know that it wouldn't generate enough energy continuously to power the motor due to friction ect so then the battery's would take up the slack, this could dramatically increase the time it takes for the battery's to run out thus increasing an electric cars possible distance without needing charge and they would need less battery's making them cheaper.
I know there is probably a simple reason why this wouldn't work which I have overlooked, but doesn't anyone else think this makes sense?
You cannot "use the spin of the wheel to make more energy". You cannot create energy! No matter where you put the alternator, eventually your prime mover must supply the energy. Look at your total energy balance.
Timelord
True Timelord,
There are systems that utilize Dynamic Braking Motors to store electrical energy in a battery for use later.
In a hybrid car engine system, the electric motors reverses function and charges the battery during deceleration.
And your point is?
Dynamic braking is exactly what the OP wants to do. He needs to realize that he is not creating energy, rather recouping energy the prime mover put into the vehicle motion. Turning the prime mover into a generator in a hybrid is much more efficient than the OP's scenario of a generator on each wheel in addition to the motor.
That's what I originally meant, the small amount which the power generators make from the motion of the wheels is put back into the electric car motor to reduce battery use. It wouldn't entirely power the motor due to the wheels not ever spinning at the RPM of the engine, however it would be another way to charge car battery's rather than using an alternator attached to the main drive.
die247,
It's called regenerative braking or dynamic braking as noted above, and is in wide-spread use now. The generators in (or driven by) the wheels require energy in the form of torque to generate electricity. It's called braking because the process of pulling that energy from the wheels causes a slowing effect on the car. So the only time it can be used without imposing an additional load on the car motor is when you are coasting and wish to slow down. It does absorb some of the energy the brakes would normally absorb. It is a good idea, just not original.
Yea I thought that a generator system in a wheel would slow it down due to resistance in the electricity generation just didn't mention it :P
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