Fieldlines.com || 17' turbine - time for maintenance

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Reviews - Diaries - Our Products

17' turbine - time for maintenance
By dlenox, Section Wind Posted on Tue Apr 14, 2009 at 02:00:19 PM MST
needed maintenance

All,
About a week ago I had noticed in my logs that my 17' wind turbine stopped turning 3x in one day in which we had 10-15mph winds.
So that day I shut it down and climbed the 80' tower to take a closer look. From the top of the tower I noticed that the gap between stator and the back rotor appeared to be almost non-existant, while the air gap to the front rotor more than it was setup to be.
So it appeared that I needed to lower the telescoping stub and perform a stator adjustment.
Last Sunday the weather cooperated enough (44 degrees 12mph winds) to allowe me to climb the tower, lower the telescoping stub and check things out a bit further.
Sure enough nuts were not completely tight around stator, so I re-adjusted the stator so that it was centered and ensured that all nuts were tightened up. Got the telescoping stub re-raised after 3-1/2hrs total work.
After all done I settled onto the bench in our front yard and sure enough the wind started up the turbine in light winds.
That is until yesterday...
Repeat situation, according to logs turbine stopped rotating again, so I went outside to check things out a little closer. The turbine was slowly rotating - 90rpm in about a 12mph wind, which 'normally' it should be turning at about 120rpm.
Sure enough I heard some occasional dreaded squeaking! But at least it was not squealing...
It appears that the original problem was probably not that the stator had shifted but more likely that the bearings had loosened up inside the hub and allowed the turbine to sag slightly, thus causing a stator mis-alignment.
This was pretty much confirmed by my log files as the turbine output was less than previously recorded.
So what I had hoped would wait till the end of summer I have to do sooner than later - that is take the turbine off the telescoping stub down to the ground.
I hope to do that within the next week, at least at that time I can do a totoal teardown and inspection. And when reassembling add some needed additional air-gap so that the turbine is not so stalled out.
I will probably also add some additional offset of the turbine which should help out with my furling issues, and possibly some lightening of the tail vane.
In the long run this maintenance/inspection will be a good thing.
Dan Lenox

17' turbine - time for maintenance | 8 comments (8 topical)

Re: 17' turbine - time for maintenance (3.00 / 0) (#1)
by christopher on Tue Apr 14, 2009 at 04:03:23 PM MST

Had the identical problem on my 10 footer after 1 year.
Tried the same first fix ,took the secound drop of the tower to fix :(

Re: 17' turbine - time for maintenance (3.00 / 0) (#2)
by wdyasq on Tue Apr 14, 2009 at 04:38:45 PM MST

Question to all - Are you running seals and grease/oil?

Thanks,

Ron
Adventure is just bad planning." -- Roald Amundsen

Re: 17' turbine - time for maintenance (3.00 / 0) (#3)
by Jason Wilkinson on Tue Apr 14, 2009 at 04:48:49 PM MST

Good question Ron, most used vehicle hub bearings ,whilse on the cehicle the seals are there when used for turbines we seem to neglect the seals
Jason

[ Parent ]

Re: 17' turbine - time for maintenance (3.00 / 0) (#5)
by dlenox on Wed Apr 15, 2009 at 06:16:53 AM MST

Ron,

Yes I am using the rear grease seal and hub was packed pretty full with grease.

I am beginning to think that the problem is not a lack of grease but more than likely a loosening of the bearings.

My 17' turbine has a fair amount of mass (weight) as I am using 1/4" steel as front and back plates to retain the blade roots. This weight extends just barely past the front dust cap.

When assembling hub I did as normal automotive techniques whereby I finger tightened the retaininig nut then backed off one star on the nut retainer.

I have kept the turbine in pretty severe stall and rpm's rarely go over 125rpm. My initial thought on this was to hopefully reduce maintenance, I know that DaveB's 17' spins typically at 250-300rpm.

So it would appear that keeping slower rpms on the larger turbines may not affect the periodicity of maintenance any more that a faster revving turbine.

Dan Lenox

[ Parent ]

Re: 17' turbine - time for maintenance (3.00 / 0) (#4)
by Janne on Wed Apr 15, 2009 at 04:01:24 AM MST

Just an idea. On my 10' i drilled and tapped a hole for a grease nipple, it's now easy to pump new grease to the bearing without de-assebling the whole machine.

The bearing i used also had a seal behind the dust cover, i removed that.
contact: #otherpower @irc.otherpower.com

Re: 17' turbine - time for maintenance (3.00 / 0) (#6)
by Dave B on Wed Apr 15, 2009 at 11:32:54 AM MST

Dave B. here. As Dan mentions I have been running my 16' now for one year and recently have lowered it for inspection and modifications for battery charging. This will be a complete tear down which I have not had a chance to do yet.

Intitial inspection indicates some play in the bearing and I am using a new 6000lb axel rated hub 6 stud 5 1/2" centers. I have been running a large gap (magnets to stator) of nearly 1/4". This was needed to assist start up as I have been heating water direct load AC no controller. If I had been running 1/8" or less this could have been a clearance problem by now.

I have kept 1/2" studs (everything stainless) and for my stator supports also lock tighting (blue) everything as well as split ring lock washers. All of this appears very secure and my blades are looking like new. Several coats of gloss white enamel, 2' of stainless tape on the ends of the leading edges and hard paste wax as a final finish. I am very impressed with the way they look after a year.

I am also using (2) 1/4" plates for my blade assembly and my dust cap extends into the rear blade a bit as an indiacation of how far out the hub assembly extends. My rear rotor is mounted on the backside of the hub plate which I think could be a bit easier on the bearing. My blades I beleive are about 11 lbs each. More updates to follow when I get a chance to tear this down. Dave B.

[ Parent ]

Re: 17' turbine - time for maintenance (3.00 / 0) (#7)
by dlenox on Sun Apr 26, 2009 at 06:52:04 AM MST

Dave,

Did not have time yet to disassemble turbine, but there definately was play in the bearings, as I could lift the whole rotor assembly and it 'clunked'.

Due to me having a brake caliper mounted I now think that there was enough of a drop in the rotor to cause the brake rotor to contact one of the brake pads. And that was the source of occasionaly stopping the rotation and the source of the squeal that I heard.

In the next week or so I plan on dis-assembling the rotor, greasing the bearings, increase air gap about .040" and make fiberglass tail vane.

This way I can put it back into service fairly quickly, by doing minimal changes

Increasing the offset from the yaw bearing may wait until another time.

Dan

Re: 17' turbine - time for maintenance (3.00 / 0) (#8)
by dlenox on Tue May 26, 2009 at 08:01:14 AM MST

All,

It's been a while since I have been able to get back around to the wind turbine, I have been busy with my solar project and making my own solar tracker.

With the long holiday weekend I was able to spend yesterday inspecting and disassembling the wind turbine. Good thing was that there were no real surprises. The main issue was that the main bearings had come loose (about 2/3 turn of the star nut) which made the rotor 'sag' thus causing the rotor to tilt - and allow the brake rotor to contact the brake shoes.

I was able to double check all dimensions and angles and they are pretty close to the specs of the Dan's 17'er, so at this point in time I don't think that I am going to increase the rotor offset like I originally thought that I might.

With the smaller turbines people don't seem to use the rear seal for the hub/rotor, but I did on mine. It seemed like a little bit of water still got past the rear seal as there was a tiny bit of accumulated rust inside the hub.

Yesterday I spent the day dis-assembling and doing visual inspection and other than a slight rub on the stator everything looked good. The rub was only enough to skuff up the outer layer of glass cloth, and did not touch the coils.

I got all the old grease removed from inside the hub and replaced the bearings with a new set as well as new rear seal. The rotors were wire brushed and cleaned up a bit, and fresh paint applied to both rotors and stator.

When it does come time to put the turbine back into service I decided that I was going to spin it using my lathe to get the new set of bearings to seat and then readjust the keeper nut. In addition I will be adding about .050" more air gap between the rotors to allow the turbine to spin a bit faster, while I have the turbine spinning I can again take some voltage readings to make sure the cut in speed is not going to be too high.

I am also going to leave off the auxiliary brake as I have been able to stop the turbine by shorting out the stator with no issues.

One last thing that I am doing is lightening up the tail a bit, I removed and weighed the 3/8" tail vane and it seems to weigh in at about 30 lbs. I am going to make a tail vane out of fiberglass/foam core and guessing that it should weigh in at about 15 lbs or so. The new tail vane will be made this week, my friend Paul Schreiner from PS Composites will be helping me since he has all the equipment necessary to vacume bag it.

As things progress I will post more updates.

Dan Lenox

17' turbine - time for maintenance | 8 comments (8 topical)

Menu

� create account
� How to use the board
� FAQs
� search the board
� Google search the board

Login

Make a new account

Username:

Password:

Total Views

��181 Scoop users have viewed this posting.

Related Links

� Also by dlenox

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest � 2009 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!