Electricity Production from Brake System

These systems already exist on hybrid cars and many newer golf cars. I'd take a look at existing technology before going too far.

It is called "Regenerative Braking" and has been around for a while. There are a few variations.

Here is one example: http://www.wisegeek.com/what-is-regenerative-braking.htm

I do not have any specifics regarding the possibility to "engage and disengage the gears with our gear system in a heavy vehicle" but I know that "Greyhound" bus lines (people transport company) has been using regenerative braking for some time now.

Their buses are quite large but not on the scale of a monster dump truck if that is what you mean by heavy vehicle.

Best wishes to your idea!

Also look into dynamic braking of locomotives. They don't use much of the energy they generate, but there have been some extensive studies along those lines.

Drew

good answer (GA)drew, I think we need to rethink shipping, as an important component in our energy mix.

A civil Engineer wrote a thesis on Cahon pass near San Bernadino California and dynamic braking. His research showed that the average train traversing that section of track could generate approx 800kwh of electricity. The standard dynamic braking setup on a train dumps the juice into a resistor bed and it is vented away with huge fans. He suggested using centrifuges to collect the energy from braking so it could be utilized later. Problem was he was looking at about 70% losses converting it around.

I suggest installing a catenary wire system like electric trains use in many cities so the recovered braking power can be transmitted to other trains going up hill or to nearby towns to augment their power grid. My research showed that 800kwh should be enough to power a house for about a month; in 2004 there were about 80 trains going through the pass every day.

So, that's 80 trains with enough juice for a home for a month, or 30 homes for a day. Or it is that much diesel saved on the uphill trains. I got no idea how much it might cost to wire up the tracks but this has to beat the wave generator that was looking at a 20 year payback (if it isn't destroyed in a storm).

Drew

Swiss trains were precisely timed so that a train using regenerative braking down a mountain could provide (some) power for a corresponding train going up the mountain.

This is another paper written by the same author, kind of a review and condensed version of his thesis.

Drew

electric fork lift trucks use this type of braking requiring only a normal brake to hold truck still when stopped

http://en.wikipedia.org/wiki/Regenerative_braking

Dear, rageshcandran, perhaps this will help you find gears; http://www.martinsprocket.com/home.htm

I'm not at all clear about < engage, disengage>, more details would help.

Is heat sink is what you are looking to recover energy from?

How heavy a vehicle? Bus, earth mover?

In most heavy vehicles, the output shaft of the transmission is always engaged with the drive wheels (via a differential, etc.). There is no auxiliary clutch at that end of the transmission. "The clutch" in almost all vehicles, heavy and light, is between the engine and the input shaft of the transmission.

There are some amateur-built electric cars which use a regen system in which an alternator is pulley-driven from the drive shaft during braking. A clutch for a system like this could be of the type used in car air conditioners (but which are built in many sizes -- search Ogura). These systems are rarely worth the trouble -- a lot of added complexity and some weight gain for a small gain in produced electricity.

In engineered electric vehicles, regen braking is very frequently built into the system, because doing so ads no weight and negligible complexity, and the gains are relatively high because the full horsepower of the power train is available for stopping duty (and thus for charging the batteries at a high rate).

In an ordinary manual transmission car, when you go down a mountain, using engine braking, you are also using regenerative braking. Part of the load on the engine (that the hill is working against as it tries to make the car go faster) is the alternator. If you turn on the headlights, the engine braking will be more effective. If you apply the brakes, the brake lights will add to electrical load, helping to slow the car. (These effects are, of course, minuscule.)

Instead of an alternator driven from the drive shaft being clutched, it could be allowed to spin all the time, and energizing the field would cause braking. More field current = more braking. Zero field current = little load on the drive train -- just the windage, belt and bearing drag.

But the short answer to your "what type of gears are used" is that there is easy way to "tap into" the transmission on most vehicles. Any pulley attached to the drive shaft would need to be custom machined, balanced, etc. It is a little easier to drive something from the "front" of the engine, where the alternator, water pump, etc is usually driven. In this case, the regen braking would only work while the vehicle's clutch is engaged -- although this is usually the case for all but the very end of a stop.

But the short answer to your "what type of gears are used" is that there is easy way to "tap into" the transmission on most vehicles.

Whooops. This was to say: "there is NO easy way"

This idea is not new. Diesel railroad engines use this all the time. Its called dynamic braking. I know this does not answer Your question but it may give You some new avenues to consider.

oilcan13

This concept has been investigated before in electric powered vehicles. I suggest that you GOOGLE "regenerative braking"....Wikipedia has good stuff on this topic

It is an important consideration for vehicles that make many stops....like buses and package delievery vans