The Overdrive

[Allan]

 

  This is something I had to try, and it has been succesful. Yes an  overdrive.Increasing the rpm 3 times. It is much more efficient then a set of belts.The housing is machined from aluminium to keep the weight down.This prop is 14' dia. with a tip speed ratio of 6. The next time it comes down I will take pictures and post them. At present it has been up since May04 and there has been no problems with it. I do not recommend it with any smaller prop. On my 10' prop it was to hard to start. Cut in speed now is less than 50 rpm.

[BruceDownunder]

Hi Allen, very interesting ,tell us more,pls.  

I've a machine shop and could make it ,I hope. I've got 14 footX3 blader in the production stage.

Thanks

Bruce

[iFred]

Yes, I would be interested in this too. as well as specs!

Thanks!

[Allan]

Good morning boys,

    As for specs (drawings) I cannot

help you with rite now, I made no drawings when I machined it,but I can explain what I've done. The planetary set is from that of a small import car I believe. It was lying in pieces at the dump.So seeing that all the parts were there (the gears) I went for it. The housing is made of 3 aluminium pieces. The front section houes 2 6205 bearings , held in by a snap ring in the housing and 1 on the shaft. This shaft accepts my prop.the planetary needs support, the other end of the shaft has what I call the quadrant (the piece with the 4 gears mounted in it).The gear that drives the quadrant from the inside is mounted on the end of the generator sfaft. The outer gear (the internal one) is pressed into the the inside diameter of the second section of the housing, this in a sense lock all 3 together to form a reduction ratio. In my case 2.8:1. The final piece to the housing is a mounting Plate that is bolted to the generator, it has a seal that keeps the oil in. Now , when I first built the unit, I found that there was quite a lot of restance due to the ratio. To cut down the restance I removed 2 gears from the quadrant . This helped considerably, so getting a little braver, I decided lets take out 1 more. So far it been 6 months and i have had no problems. I think that if the prop had too great of reverse torquing loads on the generator the fit on the internal gear could fail in the aluminium. I will look to see if I have any pictures of this unit I built and post them. I am a certified machinist and millwright by trades this project is not for the beginner.

          Til later   Allan

       

[BruceDownunder]

Thanks Allan.

I've allways wondered how a small gear box would work -you are the first one that has delivered ,I think.

Waiting for pictures of the set-up ,if it's possible, please.

Thank you again

Bruce

[Allan]

 These are pictures that I took at the end of the summer. It will be some time I think before the wind machine comes down again. The outside dia. is 9" and the overall length about 7" . The shaft is 30mm. dia. and keyed for the hub.  

             Allan

[Drives]

This is great, thank you for sharing.  Could you tell us about the electrical ratings of the generator, and the type of performance you have seen from it under different wind conditions?  This is an excellent design.