Mechanical blade furl

[Fiddlehead44]

This may be an old idea. I don't know. The blade has an internal

hole that allows a shaft to hold it in place. The blade and shaft

have spiral grooves that allow a 90 degree swing and is controlled

by the upper tension spring. The furl is easily adjusted with the lock

nut. Higher RPM's would cause centricifal force and furl the blades

   Fiddlehead 44

[drdongle]

It was hard to make out you illustration but I think what you doing is changing the blade pitch. This has been done before and can work quite well, The Jacobs machines use it.

[Fiddlehead44]

Yes, you are correct. As the RPM's increase the spiral base

wants to pull outward and thus changes the angle to a furl

neutral angle. The spring under tension trys to prevent this

action and will in accordance to how much tension is applied.

This would prevent high wind damage and produce a more

constant charging RPM.

[Flux]

You will have to devise a mechanism to synchronise the blades so that they all move together, otherwise it will vibrate and go out of balance.

The concept is the same as the later Jacobs governor but their mechanism does not allow individual blade movement.

The variable pitch idea is a good one but don't under estimate the problems in making it reliable.

Flux

[Fiddlehead44]

Thanks for your interest. I felt that if the blade weights,

friction and spring tension was identical, then the system

would work (or)

[deloiter]

I tried something very similar with disasterous results. No matter what I did I couldn't get the blades to move at the same time. One would slide out which made for an immediate and almost destructive imbalance. It slowed down due to the vibration and as far as I could tell no more than one blade ever rotated and extended. I was very certain it was perfectly tuned because it got to the point where it wasn't the same blade each time that extended. I gave up realizing that some mechanism was needed to insure that all blades operated exactly the same at exactly the same time. I hope you will fare better than I did.  I have since built gennys based on Hugh's swinging tail design which has so far been fool proof.

[wpowokal]

Search this site,

http://www3.telus.net/pearen/dunlite/Dunlite.htm#LM

In the list of turbines VP = variable pitch, this will show how to keep all 3 blades equal.

allan down under