Wind Turbine Transmission

[RP]

Chris,

Consider putting a small magnet in your oil bath to pick up the steel wear particles so they don't keep recirculating with the chain.

[tecker]

I Know lube for this transfer is probably something you considered but discarded because of seals and stuff .  An oil bath will keep the chain from shedding and loosening up . If the larger sprocket were on the bottom if would sling enough oil to work .a magnet in the oil bath.
So a closed mech with a sight glass ,oil level below the bearing so the large sprocket can pick up . I've used spline belts and they last for a while but they loosen up and come off .

[jarrod9155]

Hi , Chris I see you plan on using the royal wind blades .  Now at a tsr of 5 that sounds a little low I have tried playing around with the low of 5 , 6 ,7 and have found that they perform there best around 6.5 to 7 tsr any lower for me I have had stalling . At lower wind speeds I spin a higher tsr and as the wind picks up I lower the tsr and that has been the sweet spot for me .

[ChrisOlson]

Hi , Chris I see you plan on using the royal wind blades .  Now at a tsr of 5 that sounds a little low

I was going by the chart for their water heating machines, which look like they run at a 5 TSR pretty much across the board.

I have the generator built for it - I'm going to try it at .467:1 ratio and if the ratio is too high all I have to do is change the pinion sprocket on the output shaft in the transmission to change operating TSR and let the blades spin faster.
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Chris

[ChrisOlson]

I Know lube for this transfer is probably something you considered but discarded because of seals and stuff

I ran the transmission for an hour last night, with the generator on it, at 75 amps continuous output.  I used #2 diesel fuel for lubricant in the transmission, mixed half and half with automatic transmission fluid.  The transmission runs so quiet that you don't even know it's there.
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Chris

[jarrod9155]

I use the mppt with Aurora inverter to bounce around with diffrent tsr and also found that the tsr on the charts they have posted on there sight show a tsr of around 5 I believe with heating water it is a diffrent animal  than battery or grid tie . As for torque these blades have it , I find that if I don't slow the  tsr down on the top end  around 160  rpms at the rotor the blades start to run away before the inverter can apply sufficient load . I would think you would want to start with a tsr of 6 or higher . The blades come alive around 10 mph and start pulling . Anything below 10mph  I spin a tsr of 7 and after 10mph  I have lowered it down to around 6 for a tsr and start to furl at 25mph  . Not sure what material they are using on your blades , I opted for ash and I am  really happy  with how there holding up they don't slow down as quick as a lighter blades so during gusting wind it seems to maintains a steadier speed. Also this last weekend noticed something diffrent with theses blades my inverter shut of and the tsr went through the roof most of been a rpm of 300or more and the machine was furling in 18  to 20 mph winds the only load was a baseboard heater , so what I'm saying is the machine was furling quicker with faster rpms ? Maybe one of the Daves can chime in and can give some advise they helped me allot with the blades .

Jarrod 

[ChrisOlson]

I would think you would want to start with a tsr of 6 or higher .

That's actually where I have the gearing set right now - the rotor will cut in at TSR 7.3, and depending on the torque, should be in the low to mid TSR 4's by the time the machine furls.  If they have more torque than I figured, they'll be running faster at furl, which will be fine.  I figured, when flying a new set of blades for the first time, that it's better to run them slightly slower than opt for the high end.  My goal with this machine is not to get big numbers on the top end, but get improved midrange performance in the 12-18 mph wind speed range.

With the way I have the gearing and generator set up, according to what I tested last night, they should be pulling in the 5-6 TSR range thruout that whole 12-18 mph wind speed.  My generator develops 744 watts @ 375 rpm, which will be 175-180 rpm for the blades.  Should be a perfect match in that wind speed range where I'm shooting for best performance.
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Chris

[ChrisOlson]

A few photos for folks that like this sort of stuff.  Took them with my cell phone so the quality isn't all that good.

Welded a flange to the transmission case for a cover:



With the cover on it:



And welded the tail bracket on - still have to weld the tail boom to the hinge.  What's on the stand in this photo weighs about 130 lbs:



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Chris

[ChrisOlson]

I opted for ash and I am  really happy  with how there holding up they don't slow down as quick as a lighter blades so during gusting wind it seems to maintains a steadier speed.

Hi Jarrod,

I forgot to mention that I opted for the lighter poplar blades.  Stored energy is one thing, but you have to get it moving.  I've found thru testing this thing that the inertia in two 25 lb generator rotors is pretty significant at 500-600 rpm.  While testing it, I hooked up a 27 watt CF light bulb direct to the generator, run it up to 120 volts AC with a hand drill, powering the light bulb, then release the trigger on the drill.  The flywheel effect of the generator rotors spinning at high speed will drive both the hand drill and the 35 watt load from the light bulb for 15-20 seconds before the light goes out.

Because of the gearing, I figured it would best to have the lightest blades possible, since the spinning mass of the generator rotors, working thru the gear reduction to the input shaft, seems to keep it coasting longer than a direct drive unit operating at 250 rpm.
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Chris

[jarrod9155]

  Great job on the craftsmanship , really has motivated me to also try or think of diffrent ways to harness the wind . Cant wait to see it all done Chris .

[windvision]

Hi Chris:

  Looking at the bolt pattern, will the corners have a tendency to leak, given the location of the bolts?? Grandpa always told me that the closer you put a bolt to the intersection of the X and Y axis, the better. What's your thoughts?

[ChrisOlson]

  Looking at the bolt pattern, will the corners have a tendency to leak, given the location of the bolts?? Grandpa always told me that the closer you put a bolt to the intersection of the X and Y axis, the better. What's your thoughts?

The transmission case is made of 1/4" thick sheet steel.  The flange and cover are 3/16" thick material.  I ran it for an hour with the generator putting out 75 amps continuous - no runs, no drips, no errors - with #2 diesel fuel in it for a lubricant.  The generator got good and hot.  The transmission didn't even get above room temperature.

It won't leak.  I'm putting a three year warranty on it that says so - at which time the drive chain will be due for inspection/replacement and the cover has to come off to replace it   

If it was made out of tin, then I'd look at bolting the corners.  Otherwise I'm not too worried about it.
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Chris

[ChrisOlson]

Some more photos as I finished the head up today.  This machine is 14' 5" long from the tip of the input shaft to the rear of the tail feather:





A top view of the furling mechanism:





There's a series of adjustment holes there to make the machine furl different.  Moving the eyebolt towards the front in its bracket gives more progressive furling and it acts like an angled hinge against gravity and will partially furl, depending on the wind speed, and govern the power at a high output level.  Moving the eyebolt to the rear in its bracket causes more linear furling - "breakaway" type furling action where the machine will stay pointed into the wind right up to max power, then "break away" and fully furl and stay furled until the wind dies down again because the mechanical advantage on the tail control lever just about goes over center.

The different holes in the tail lever change power output - it's in the high power position in the photos.  Move it towards the hinge and the machine puts out less power.  The preload on the spring fine tunes it by adjusting the eyebolt.

I know, I know, gravity is more reliable.  But gravity ain't adjustable.  This is.  And it's a proven system, being flown on every turbine I have built over the last year, which I believe is seven of them.  This is #8.  Some of them have spring cylinders.  The last two I've used simple extension springs like this.

Some photos of getting ready for paint:







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Chris

[cdog]

I recently read on another site about a 7 phase f&p alternator that has virtually no cogging.
Could this be a good match for gearing up to almost any desirered speed?.

[ChrisOlson]

I recently read on another site about a 7 phase f&p alternator that has virtually no cogging.
Could this be a good match for gearing up to almost any desirered speed?.

I have no idea, man.  What I finally settled on for this one is 50 turns of 12 AWG wire in a 12 pole, 9 coil delta, with 2 x 1 x .5 N40 bar magnets at 1" air gap.  After much tinkering, I found out that this is a case where you have to build some resistance into the winding to keep it from being too stiff.  I played with single rotor (just one rotor with magnets), single rotor with magnets with a blank steel plate on the other side of the stator, and dual rotor (both with magnets).  I played with wye and delta.  Wye don't have any amp capacity and delta worked better.

The dual rotor (both with magnets) worked the best simply by opening the air gap to make it weaker.  Then add more turns to get the voltage at cut-in, and use the extra resistance of the additional turns at high output to keep the generator from pushing too many amps and turning too hard.  The generator came in at like 22 rpm/volt.

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Chris

[ghurd]

I recently read on another site about a 7 phase f&p alternator that has virtually no cogging.
Could this be a good match for gearing up to almost any desirered speed?.

No reason I can think of to gear an F&P.
The F&P limits are built into the F&P.
Reconfiguring the coil connections is the electrical equivelent of gearing.

It's looking good Chris.
G-

[Harold in CR]

 Awesome project. Very nice set up. Should do a fine job of generation for you, Chris.

[jarrod9155]

Do you have your blades yet . Lets see this thing Spin 

[ChrisOlson]

Do you have your blades yet . Lets see this thing Spin 

Dave M had the blades done, they had to put the sealer on them, and Dave B was making the crate yesterday to send them out.  They'll be here sometime next week.  I still have to build a blade hub - haven't started on that yet.

I think I might add some pulleys and cable guides to put a tail crank on it like a Bergey too.  I welded a stud on the tail boom to attach a cable to for a tail crank.  I wasn't going to do that, but then decided I will anyway.  Dave B told me that those blades make enough startup torque from a dead standstill to turn his machine in decent winds with the mechanical brake set and make the brake squeal.  So I decided a tail crank would probably be a good idea.
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Chris

[tanner0441]

Hi Chris

You said you were using diesel to lubricate your chain. I used to work for a company and we had a Churchill crankshaft grinder, we used a lubricant called spindle oil.  It had a very high shear resistance the viscosity was 1.2 to 1.9 it was a high sulphur and phosphorus base with added zinc. It also had very good moisture rejection and low foam, which I would have thought could be useful in your application with the fact your gear box is very exposed to temperature fluctuations and the risk of condensation.

Diesel has a reputation for absorbing moisture.

It wasn't that expensive and because it inhibited corrosion we used it for all sorts of other jobs, including spraying the beds on surface grinders, millers,  and shapers.


Brian

[ChrisOlson]

Since I have this turbine basically completed I decided this is the time to do some testing with different stator and magnet rotor combinations to see what results I get.  What I have found so far is pretty interesting when you try to spin a permanent magnet generator at high speed and still match a slower turning rotor's power output.  Flux and some of the other guys that build generators might find this interesting too.  I had to re-think my generator design for this thing again, but I got enough different stators and mag rotors just laying around the shop that I can come up with a half dozen different combination just by re-wiring them delta and see what they do.

What I've decided is that I can cut the cost of the generator to about 2/3's of a direct drive unit.  You still need two generator rotors - but only one has to have magnets on it.  So I started calling this rotor combination a "mag rotor" and a "core rotor", since the rotor without magnets acts as a core to channel the flux lines.

When I tested this on the lathe I didn't get the results I expected.  But I used two rotors that were the same size.  The flex density was .3510 tesla in the air gap (.800") vs .6075 with two mag rotors, or about 58%.

Tonight I got a wild hair and tested this using a 10" mag rotor and an 11" core rotor.  The flux density rose to .4135 tesla, or about 68%.  Evidently you need to use a bigger core rotor than mag rotor to capture flux lines that extend outside the perimeter of the mag rotor to properly concentrate them in the air gap.

Even the combination using a 10" mag rotor and 11" core rotor is way too powerful.  So I opened the air gap to a full inch figuring this would throw my cut-in way off.  It didn't.  5 rpm on the input shaft is 10.7 rpm on the generator and the rpm band of the generator increased considerably with the wider air gap, and it got less "stiff" and less hard to turn at higher output over 50 amps.

A little more resistance in the generator winding actually helps the power curve.  The extra resistance doesn't seem to hardly make any difference below 50 amps, and it makes the generator easier to turn at outputs over 50 amps.  The easiest way to get that needed resistance, and still get the ampacity needed, is to reduce the flux strength and use more turns of large wire in delta configuration.  This is a 12 volt machine, so it has to be able to handle 100+ amps.

This is only a .467:1 overdrive, meaning for every turn of the input shaft, the generator spins 2.14 times.  I'm pretty sure one of these could be built using ceramic magnets instead of neos.  Better results would probably be achieved with ceramic mags (and less cost).

After several hours of running time testing in the shop, the transmission is now "broken in" and it spins so free that if I spin it up to 300 rpm shaft input speed I have to grab the input shaft to stop it because it will spin for almost a minute before it comes to a stop by itself.  The "losses" in this type transmission drive are negligible.

Also, thanks to Brian for the comments on lubricant.  I'm going to stick with the half and half #2 diesel and ATF.  We get winters here at 30 below F and with #2 diesel in the gear case it will spin freely.  I added the ATF because it has a lot of zinc in it and gives the diesel fuel better lubricity.  I'm not worried about the hygroscopic properties of diesel fuel because I decided to build the transmission hermetically sealed so no moisture can get in thru a breather.  The temperature rise of the transmission at high outputs around 75 amps for an hour is zero, or at least not measurable with my infrared meter that I use to test diesel engine exhaust port temp.  And that meter is accurate +/- 1 degree F.  I imagine there's some heat generated in the gear train, but it's absorbed by steel mass and dissipated before it can be detected.  An oil bath chain transmission is an incredibly efficient drive, especially at the input shaft speeds that a 12 foot turbine rotor can run at.

This has been one of the more fun turbine projects I've done and I'm extremely pleased with the testing results.  My new blades should be here next week, and then I can complete the rest of it.
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Chris

[ChrisOlson]

Some folks might be interested in how I test these things, so here's some photos.

A closeup of a delta wired stator:



I got a rectifier out of a 90 amp delco alternator hooked up.  I use small 14 AWG wire from the generator to the rectifier to simulate wire run resistance



This is the setup I was testing tonight - generator with a mag rotor and a core rotor.  I got meters hanging on everything it seems.



This is the test setup - turbine on the stand, Sun AVR on an upside down garbage can, old junk Interstate battery on an upside down 5 gallon pail and meters hanging on everything on both the DC and AC sides.  The AVR has a carbon pile in it so I can load the battery to keep the voltage at 14.5.  I drive the turbine with a Ross TF-series torquemotor (hydraulic - not shown in the photo) with hydraulic power supplied by the remotes on my CaseIH 7120 Magnum tractor.  The torquemotor can put out 36 horsepower and 343.8 lb-ft of torque @ 550 rpm @ 2,600 psi and 23.75 gpm flow rate.  The torquemotor is mounted to another stand and drives the turbine input shaft with a PTO shaft with u-joints so I don't have to have perfect alignment.

Not quite as classy as hangin' a Volvo on a bumper jack and driving it with one rear wheel.  But us Wisconsin Northwoods Hicks do the best we can with what we got   


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Chris

[kevbo]

Diesel fuel is not any more hygroscopic than other fuels or oil. It is just that diesel engines have zero tolerance for water in the fuel, and the biologics that water allows to flourish also cause problems. The latter could be an issue for you, as some of the bugs produce acid compounds that will cause corrosion issue.  You can get biocide treatment for diesel fuel, and that might be worth using.

If you seal the gear case, you need provide a bellows or diaphragm  to allow pressure to equalize pressure changes due to barometric pressure shifts and case temperature.  If you don't do this, air will be sucked in and out past the shaft seals, and over weeks and months, significant moisture will condense inside the gear case.

One way to do this would be to make the gasket under you lid full profile (rather than just the perimeter) make it rubber or neoprene, and put a vent hole in the lid, so air can move in and out behind the gasket, relieving most of any vacuum that might form.  Won't have much motion, but might be enough.   Another way would be to attach something like a limp balloon to a vent pipe. Balloon would not be durable, but maybe a chunk of bicycle inner tube or maybe a football bladder?  The bladder can go on the inside or outside of the case...more room outside, better protected inside.

I used to work on High voltage systems that had to stay very dry to avoid corona discharge problems, and doing this was one of the keys, and we didn't have any dynamic shaft seals to worry about. We used bronze bellows.
 
Also, synthetic ATF will have a much lower pour point than the mineral based stuff, so that might be a way to handle the low temps without using fuel oil to cut the ATF.

[poco dinero]

Chris, if your wife puts up with all your shenanigans and all the time you spend  on developing wind turbines she must be a real sweetheart.  Most guys would have been divorced by now.

Remember the old C&W song "She can put her shoes under my bed anytime, anytime she wants to, that'd be okay.

That said, I salute you, your wife, and your pursuit of better wind turbines.

poco

[fabricator]

He happens to be married to a Actual Swedish Goddess who has a CDL and could put most professional truckers to shame, she has also been known to kick sworn officers of the law right smack in the nads (the guy happened to be an ahole and picked the wrong gal to prove it to) She can also cuss somebody out in at least two languages.

[freejuice]

He happens to be married to a Actual Swedish Goddess who has a CDL and could put most professional truckers to shame, she has also been known to kick sworn officers of the law right smack in the nads (the guy happened to be an ahole and picked the wrong gal to prove it to) She can also cuss somebody out in at least two languages.

That's a Viking Goddess

[fabricator]

I wouldn't want either viking or the swede pissed off at me.

[ChrisOlson]

He happens to be married to a Actual Swedish Goddess

LOL!  Being my bride is Swedish she understands the importance of wind power a little more than the average American woman.  She's as excited as I am to see a new turbine fly and she fully believes that we should be petroleum free, like Sweden has announced they're going to be by 2020.

Americans are born and grow up taking it for granted that everything runs on oil.  Cheap oil.  Without it, this entire country comes grinding to a halt.  It's not that way in other parts of the world, and I'm lucky enough to have a bride that knows that.
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Chris

[ChrisOlson]

Haven't given up on this geared turbine yet.  In between blizzards and plowing snow all night I've found some time to work on it.  Got the blade hub built and the rotor mounted.  We've had sub-zero temperatures for the last week but hopefully I can get this thing on the tower before Christmas if we get a nice day to work outside.









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Chris

[bj]

   Chris:  now that is a blade mount.  Nice stuff.  Good luck on the weather, I'll be moving snow before we can even
think about going anywhere.

[jarrod9155]

Looking good !! , I would say overkill on the hub but over killing it last LONGER 

[ChrisOlson]

Looking good !! , I would say overkill on the hub but over killing it last LONGER  

Well, I kicked around various ideas about how to do that hub and settled on the hub weldment assembly shown in the photos.  That weldment is roughly half the weight of using two 1/4" plates, supports the blade roots out about 14" from the input shaft (28" diameter overall), and is more rigid and resistant to flex than using plates.  It also provides for zero error assembly of the rotor as far as distance between blade tips, since the roots fit snugly in the angles on the weldment, and simply bolting the blades on sets the tip distance at precisely 127-7/8" without having to mess with measuring it to make sure it's right.

It was not the easiest thing to build, however, due to steel tending to "pull" when you weld on it and keeping the thing running true without having to shim the blades to set trip tracking.

I was quite happy with how it turned out though.  The tip tracking was within 1 mm and the static balance of the rotor assembly was perfect out of the box, with no weights required to balance it.  I'll have to re-check static balance after I sand the blades out and paint them.  But initial assembly went quite well once I got the hub built.

The turbine turns so easy that all I have to do is lay a 1/2" SAE washer on one of the blades about three feet out from the root and it turns the machine.  It's pretty hard to beat ball bearings if you want a machine that starts up at 3 mph wind speed   
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Chris

[keithturtle]

 with #2 diesel fuel in it for a lubricant. 

Just don't forget the Motorkote.  But then, you new that

https://www.motorkote.com/Products.aspx#139

Turtle, "got it motorkoted"