Author Topic: Harris turbine bearing replacement  (Read 5951 times)

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Buzzsaw

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Harris turbine bearing replacement
« on: July 18, 2016, 10:35:35 PM »
Greetings, all. I have a 48V Harris pelton PM turbine that's been running pretty much non-stop for about ten years. A couple of weeks ago, it suddenly started to make a low frequency, grinding sound. It still is generating power, maybe at about 90%. Hard to tell because I'm starting to move towards a low water time of year.

I suspect that a bearing or bearings are going, but there's precious little information on what replacement bearings are used and what the preventative maintenance cycle is.

Any information on the specific bearings needed or any other thoughts on the symptoms would be greatly appreciated. I see mention of a 6203 bearing from a post in 2010, but there are so many sub-space to the 6203, I'd just be guessing without taking the turbine offline and disassembling (it's up in the Cascade Mountain Range). Thanks!

 - Marc

thirteen

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Re: Harris turbine bearing replacement
« Reply #1 on: July 19, 2016, 03:29:20 PM »
Possible calling the manufacture and ask. Being 10 years old things have probably changed. Unless you have an old book on them, tearing it down would be the last resort to get the numbers. Because it would shut you down  for at least 2 days, unless you have a backup you could use for a couple of days. I don't know the distance for parts. Me I'm 45 miles from the nearest parts place so a 90 miles round trip. If they would have them.
To maybe get you by as an idea if you can see the seals on the bearings use a small syringe with a small needle and inject into the bearings some grease. I assume these are greaseless bearings. This works but it will not be good for long duration. It will get you through. Bad bearings going out will as you know cause windings to get trashed.
I think stream engine turbines say to replace the bearings every 2 years. Two of my neighbors have that style of turbine. 13   
MntMnROY 13

SparWeb

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Re: Harris turbine bearing replacement
« Reply #2 on: July 20, 2016, 11:01:34 PM »
The 6203 is a very common ball-bearing design making it easy to find in a wide variety.  It's likely that ANY 6203 will fit and run - but will it last as long?  I bet this bearing isn't working too hard if it has lasted so long.  Sometimes you can figure out in advance if the bearing is heavily loaded or not, to determine what quality you require.  If you got 10 years out of these bearings under the combination of speed, load, and torque between your Pelton and the genny, then it's a safe bet that an equivalent bearing will last as long.    Can you stop the turbine temporarily and read the part numbers on the side?  Bearings are often hard to access so there's only a small chance you can do this.  Getting a look at the kind of grease shields in it would also help.  I would be surprised if it wasn't sealed.

Given the life you expect, and spreading the cost of a high-quality bearing over 10 years...  just pay for a SKF or a FAG bearing and don't worry!
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

thirteen

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Re: Harris turbine bearing replacement
« Reply #3 on: July 21, 2016, 11:04:06 AM »
Side note. If by chance you find out that you have an odd set of bearings and seals and they are hard to get. You might want to get spares and put them on the shelf. 10 years from now they maybe harder to acquire. Be sure and date the spares if you decide to get them. Plus any problems you had replacing them. 13
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skid

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Re: Harris turbine bearing replacement
« Reply #4 on: July 22, 2016, 04:11:03 PM »
Take it apart before it self destructs. There should be one bearing on either side of the pelton wheel on the shaft. The bearings will have a number stamped on them. One bearing is likely a deep groove ball bearing designed for both axial and radial loads, the other end is probably a standard groove ball bearing designed for radial loads only.

Buy new bearings and re-install them. Should only cost you $50 or so. You'll likely need a bearing puller to get them off the shaft. To get them back on the shaft easily, put your oven on approx. 150F and heat the bearings a little so they grow a few thousands of an inch. They will slide easily onto the shaft.

joestue

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Re: Harris turbine bearing replacement
« Reply #5 on: July 22, 2016, 11:12:44 PM »
i really doubt that they installed an angular contact  ball bearing in there.

Skid, i'm curious as to where the difference between DGRBB and RBB came from.

The 15 degree contact angle which seems to be the maximum for the "Conrad" style of ball bearing, produces the mathematical relationship that the maximum thrust (axial) load of the dgrbb is one half of the maximum radial load, the ratio of which is exactly accounted for by the fact that all of the balls make contact for axial loading at 15 degree contact, but only half of the balls make contact for radial loading and of those, the distribution of radial load has a predictable coefficient. . anyhow, i did look into this myself when i found the folks on the cnc forums trashing the conrad style bearing as unable to support any substantial axial load, this isn't the case at all. its just that, bearing manufactures are cheap and microns do matter.


6203 bearings are extremely cheap, but i wouldn't be putting 2$ bearings in a hydro turbine.

you may want to look into ceramic bearings, do you know yet why they failed?

mab

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Re: Harris turbine bearing replacement
« Reply #6 on: July 23, 2016, 08:05:52 AM »
I second Skids advice of take it apart before it self-destructs otherwise you may be looking for a new pelton wheel. I'm speaking from (expensive ) personal experience.

skid

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Re: Harris turbine bearing replacement
« Reply #7 on: July 23, 2016, 03:04:05 PM »
Being a Pelton wheel I would expect there to be a splash shield on the shaft or part of the casing, or some type of labyrinth seal to protect the bearings from direct water spray. The bearings will likely be a grease filled sealed type. He may just need to re-grease it if there are grease zerks, but after 10 years I'd say he got his money's worth and time out of the bearings.

In regards to inexpensive bearings, I'd only use top of the line bearings in this application such as the SKF mentioned earlier, and use the exact same type with the same type of seals. I'm sure it spins at quite a high rpm too.

Speaking of Pelton wheels, I have a stainless steel wheel from a 3.5MW unit that I put my house numbers on at the start of my driveway. Looks pretty cool 8) I need to find something to do with the injector nozzles though as I have a few...
« Last Edit: July 23, 2016, 03:10:34 PM by skid »

skid

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Re: Harris turbine bearing replacement
« Reply #8 on: July 23, 2016, 03:09:09 PM »

Skid, i'm curious as to where the difference between DGRBB and RBB came from.

The 15 degree contact angle which seems to be the maximum for the "Conrad" style of ball bearing, produces the mathematical relationship that the maximum thrust (axial) load of the dgrbb is one half of the maximum radial load, the ratio of which is exactly accounted for by the fact that all of the balls make contact for axial loading at 15 degree contact, but only half of the balls make contact for radial loading and of those, the distribution of radial load has a predictable coefficient. .


I never knew how much loading a deep groove could take. Thanks for the explanation. There wouldn't be much axial loading on a pelton, even in a vertical shaft application, as the loading is balanced.

Buzzsaw

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Re: Harris turbine bearing replacement
« Reply #9 on: July 24, 2016, 10:37:21 PM »
Thanks all for the quick responses. My takeaway is replace the bearings. The cost is relatively inexpensive and good insurance against blowing out the whole Peltom wheel and generator. I'll probably puchase a few thicknesses of 6203's to have on hand we me since I'm out up in the mountains and going back and forth to get the right sizes would be a pain.

Shame there doesn't seem to exist any exploded parts diagrams or replacement parts listings to ease the process.

DamonHD

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Re: Harris turbine bearing replacement
« Reply #10 on: July 25, 2016, 12:36:51 AM »
Maybe you should do a write-up here or elsewhere where search engines can find it for the benefit of the next person in your situation!

Rgds

Damon

PS. Some stuff does come up with this search: https://www.google.co.uk/search?q=48V+Harris+pelton+PM+turbine+bearing

hiker

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Re: Harris turbine bearing replacement
« Reply #11 on: July 25, 2016, 01:07:07 AM »
Well if your going to heat the bearings....ice the shaft...😜
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TDC

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Re: Harris turbine bearing replacement
« Reply #12 on: July 25, 2016, 06:08:10 PM »

I'll probably puchase a few thicknesses of 6203's to have on hand we me since I'm out up in the mountains and going back and forth to get the right sizes would be a pain.

This site says 6230's.  http://www.kansaswindpower.net/hydro%20electric.htm   
6203's are a very common bearing, but they don't come in differing widths, they are 17mm ID x 40mm OD x 12mm wide.  6203-2RS is the bearing with 2 rubber seals. I second the suggestion of getting high quality bearings like SKF.   New old stock SKF can often be found on ebay at very good prices. I recently bought $200 bearings for $25.  Here ya go,  $6.83 with free shipping.    http://www.ebay.com/itm/Qt-1-SKF-6203-2RS-SKF-Brand-rubber-seals-bearing-6203-rs-ball-bearings-6203-rs-/131333503378
« Last Edit: July 25, 2016, 06:14:52 PM by TDC »

SparWeb

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Re: Harris turbine bearing replacement
« Reply #13 on: July 26, 2016, 10:26:45 PM »
Quote
...a few thicknesses of 6203's...
Yes, like TDC, I can't help wonder if there's some uncertainty about the bearing specification here.
If you ask for a 6203 bearing you get only one size.  Period.  The only choice you have is the seal on the side.
It would be a capital offense if the manufacturer of the Pelton turbine selected a hard-to-find bearing.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

Harold in CR

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Re: Harris turbine bearing replacement
« Reply #14 on: July 27, 2016, 03:18:40 PM »

 After reading that info on bearings further up this thread, I hesitate to add anything, other than my bearing supplier recommends electric motor bearings as being the longest life bearings in a lot of situations.

Buzzsaw

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Re: Harris turbine bearing replacement
« Reply #15 on: August 20, 2016, 09:50:47 AM »
I can confirm now that the Harris Pelton does in fact utilize one 6203RS bearing in the very bottom of the cast housing PM generator head. Replacing this item made all the difference n the world. If fact, I now realize how much the turbine had been vibrating even without the nasty sound it started to make. Given the price of the bearings on Amazon, I bought a stack of ten and will put it on a regular maintenance cycle to replace every few years.

While apart, I also took advantage of replacing the Pelton wheel as some of the bronze cups had worn completely through or were paper thin from exposure to fine grit in its early years.

Lastly, there's a pin bearing cap at the top of the spindle integrated into the lid I'd the cast generator head. I'm not sue if it can/needs to be replaced or what the model number is. I think this just regressing should be sufficient (for now). Thanks for the great suggestions, all.

skid

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Re: Harris turbine bearing replacement
« Reply #16 on: August 20, 2016, 01:17:58 PM »
Lastly, there's a pin bearing cap at the top of the spindle integrated into the lid I'd the cast generator head. I'm not sue if it can/needs to be replaced or what the model number is.

The 6203 bearing will take most of the loading, but you should also replace the needle bearing as well. There are special bearing pullers for pulling "blind" bearings. The needle bearing will also have a number stamped on the outer race and needle bearings are inexpensive and readily available too. At a minimum I hope you packed some grease in it...

With the new runner and bearings you should see a significant increase in generation 8)

Buzzsaw

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Re: Harris turbine bearing replacement
« Reply #17 on: August 21, 2016, 11:14:19 AM »
I'll pull the cap and see if it's obvious, thanks. It was getting dark, so reassembly while the order of disassembly was in mind took precedent.  ;)

...but to pull the cap off now and check will be trivial during the day. Oh and yes, i gave it a shot of grease.

SparWeb

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Re: Harris turbine bearing replacement
« Reply #18 on: August 28, 2016, 09:26:10 PM »
Excellent!  May your hydro repay you for the TLC with many more years of service. 
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

Jedon

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Re: Harris turbine bearing replacement
« Reply #19 on: March 22, 2017, 10:57:05 AM »
Thanks for all the info, I need to do this as well. I contacted Dennis Ledbetter at Harris Hydro / LoPower Engineering and here is what he said:
"Change the bearings- recommended every 3 years.  At least grease the top bearing- just a little."
"drive end bearing is a standard sealed 6203 ball bearing. top bearing ( in the cap ) is a needle bearing found in many automotive alternators INA NB-1."
-Jedon