Hybridization spring! Bicycle Mechanical Assistance

[Gaston]

10 kw during 15 second this makes 10 000wh / 3600x15 = 41 Wh
Is the calculation correct?

The calculation is correct.

The stored energy per unit mass can reach approximately, in J / kg:

• leaf springs: 25 to 40
• tiered leaf springs: 80 to 120
• coil springs in compression: 200 to 300
• torsion bars: 250 to 400

For 41 Wh there is no need for a trailer!

For 41 Wh = 147 600 J, you need a helical spring of 492 kg (you will need a trailer)

Note:
For energy storage in mechanical form, the flywheel is much better (up to 500 000 J / kg).

[raymon]

After reading your link I find that actually a steel spring is much too heavy 600 kg for 10kw for 15 seconds, for cons I understand better why for the bike the spring is carbon fiber there it changes a lot:

Carol Livermore: Carbon nanotube springs can potentially achieve an energy density comparable to that of Li-ion batteries, even though we're not there yet.

http://www.techniques-ingenieur.fr/actu ... gie-25206/
Carbon fiber is much lighter and more elastic than steel. See the table on this site:
https://gernitex.com/fr/ressources/fibr ... roprietes/
It is true that I will have to do my reasoning directly with carbon fiber there it is very different. Here it may be playable.

[Gaston]

It is true that I will have to do my reasoning directly with carbon fiber there it is very different. Here it may be playable.

Playable for a bike, but probably still not for a car.

If we assume the gain between the carbon and the steel proportional to the ratio strength / weight given in the Gernitex document, we gain an 22 ratio.
For a car, it would make a spring of 22 kg of nanotubes (at what price?).
For a bike, the energy to be stored is much lower: 500W for 15 seconds = 2Wh = 7500 J, a spring of 1kg could do the trick.

The nanotube springs seem rather to be positioned in two niches: high power and long-term storage without loss.
(Note that the TI article is from 2009 ... and we have not seen any ads since).

[izentrop]

Hello,
Raymon, thank you for the docs but all is hypotheses and calculations.
200 m in 15 dry = 48 km / h, fast for a bike?

For a bike, the energy to be stored is much lower: 500W for 15 seconds = 2Wh = 7500 J, a spring of 1kg could do the trick.

The nanotube springs seem rather to be positioned in two niches: high power and long-term storage without loss.
(Note that the TI article is from 2009 ... and we have not seen any ads since).

The whole problem is there, promises

If he is honest the guy kisskisstrucbank uses, the money is placed until the day it will be feasible. From project to completion, there is often a difficult time to define.

[raymon]

For a car, it would make a spring of 22 kg of nanotubes (at what price?).

I think it's carbon and not nano carbon that may be interesting.

average values ​​calculated on HexcelTM's HexTowTM fiber range.

http://www.hexcel.com/fr/technology-breakthroughs

200 m in 15 dry = 48 km / h, fast for a bike?

I talked about a car not a bike 10 kw on a bike is a lot.

[Grelinette]

It's amusing to see how we can twist physical data in all directions to conclude that a system is ultimately not of great scientific interest ...

And yet ... when we see all the systems made, from the start-up aid of the mower quoted by Macro, to the inertial wheel of some sports cars or public transport, we imagine that the preliminary scientific studies for these projects, made by specialists, had given promising results to try the experiment!

Afterwards, it is a question of means available and risk taking (means and economic risks mainly).
That said, there are many mediocre products that are very successful economically, like very ingenious products that do not find their market!

Hello,

This system with spring reminds me of the little children's cars that rub on the ground to tighten the internal spring and let go: the car starts suddenly at full speed but stops 1 or 2 m further!

Friction cars? A flywheel but no spring. On a normal scale, they would make a huge weight.

I'm talking about a toy with an internal spring: the car is rubbed in reverse to tension the spring, which is moreover a "click click click", then the spring relaxes and propels the car fully over a few meters.

By the way, looking for the small spring car on the net, I found that approaching the spring hybrid bike: http://french1.peopledaily.com.cn/Sci-Edu/8073710.html

Spring hat.jpg (54.63 Kio) Accessed 6087 times

[Ahmed]

That said, there are many mediocre products that are very successful economically, like very ingenious products that do not find their market!

It is that the purpose of the products is not the utility for the user, but the simple value of exchange, value in which enters a very variable proportion of utility * ... it is the exchange value that interests the manufacturer / seller and it is this criterion that fully determines the product.
There are several simple ways to illustrate this: the quantities of goods are in quantity more than sufficient to satisfy the "needs" of all (at least the basic needs), the fact that this is not observed is significant; then, the existence of advertising proves, in the hollow, the lack of usefulness of what it dangles.

* The value of use (utility) of the product can coexist with the exchange value insofar as this one influences possibly the capacity of the product to be sold and thus to realize the condition of the expression of the value of d 'exchange.

[raymon]

* The value of use (utility) of the product can coexist with the exchange value insofar as this one influences possibly the capacity of the product to be sold and thus to realize the condition of the expression of the value of d 'exchange.

There is also the show off being able to say "I have the beautiful hybrid 4x4 that does not pollute"!
the carbon spring to 20kg to hybridize a car that shines less than a Prius but it would have in terms of economy / profitability may be more effective but just see your reactions naughty to understand that many consumers will prefer the Prius .

[Ahmed]

The "show off" is part of a cultural (in) utility that advertising knows very well how to sell (for lack of real utility)!

The system of energy accumulation in a spring is very effective, but rather limited as to the amount of energy stored ... this explains some divergences of points of view.

[nicomahe]

Hello all,
the adventure of our fiber spring is not over.
Spiers-carbon gave birth to GO Wheel which is our marketing name. At the end of June, we are organizing a CrowdFunding campaign in pre-sale mode to allow us to release the first models for the general public.
We are still in the proto that evolves with each new version.
What would not we do to help our planet?
The thrust is now stopped at 15 meters, largely sufficient in urban areas and these 15 meters of thrust will allow electric assistance bike to extend the life of their battery 5 times longer by relieving them of the effort provided during start-ups .
fewer refills, more distance traveled, less lithium produced or reduced battery size.
The GO Wheel rear wheel weighs in both 2Kg but brings tons of benefits!
To brake is to accelerate! is our catch and we are proud of it.
Join our ranks on facebook / GWCM1, our community (moderate to keep your peace)
Thank you Econology for this super smart site
Do not hesitate to ask us questions