Substitute bearing advice needed

[Dadatwins]

My Rayco 1625A appears to be getting ready ready to toss out another set of bearings, grease starting to ooze out of inner seals when running I believe is precursur to failure. Unit is setup with 2 Sealmaster NP-24 1 1/2" at the cutter wheel. Do not know why the manufacturer set up a stump grinder with ball bearing units on a cutter wheel. This will be second set as I come up on 200 hours on machine. I contacted Rayco about a different bearing setup for unit as I would like to try a tapered roller type like carlton and vermeer use. Rayco will not offer a substitute. Sealmaster does not make a NP-24 bearing with tapered roller bearings. When the first set was changed by the dealer they tried to substitute a link-belt bearing but the bearing collar was to narrow and could not be used. If anyone can get me the specs on the sealmaster np-24 and suggest a same spec tapered roller bearing I would be grateful. I can do the install but understanding and matching the different types of bearings has me dizzy. Thanks for any help.

 

[juststumps]

dada,, bummer...200 hr... 2 sets of bearings on the wheel....that sucks!!! drop lumberjack a note...he's an rayco user...might have some tips...

 

[Ekka]

Hey Dadatwins

I reckon you should read this thread.

http://www.arboristsite.com/showthread.php?t=22011

How often and how much do you grease those bearings?

And you may have just discovered a design flaw, pillow block roller bearings on a stump grinder oh my, how stupid are these big co engineers, you sweep stumps to grind them and have a lot of horizontal directional force.

Ideally stump grinders need a thrust bearing to take the horizontal force of the sweep in addition to the standard pillow block set up. But check out the thread.

 

[Dadatwins]

Few pumps of synthetic high temp grease before use. Discussed this last time with my dealer and he agreed my greasing method was not problem. Went back and forth with Rayco on bearing replacement and they claim there are too many variables to say why the bearings are failing. Thay can offer no substitute but original part. I have looked at a few dozen web sites selling bearings but can't find exact measurements for collar and bolt patterns. Like this machine and understand bearings are a wear item, but 2 sets in 200 hours is getting old. This is the only manufacturer using roller ball bearing in this application. Vermeer, carlton, bandit all used tapered roller bearing. Rayco can't explain that to me either.

 

[a_lopa]

are you using standard teeth??

 

[Stumper]

The pounding and side loads are why I have assumed the manufacturer recommends greasing so often. The SealMasters are supposed to be th be all and end all of bearings but I have not found them to be any better than Peerless or Browning (In fact I think that Browning may be better) just more expensive by about 40%. If a crossover for a tapered roller bearing exists the bearing house is the place to figure it out. If not, buy one of the cheaper brands and go on your merry way.

 

[Proj Eng]

I'll tell you why they set it up that way, cost, plain and simple. Plus they'll try to get your parts business when stuff craps out. try out these guys.
QM Bearings.
http://www.qmbearing.com/ECPillowBlock.html

And if having thrust loads, get the eccentric collar locking if you have room. I haven't used these guy's bearings yet, but I have them as back up in case of a major failure with my current bearings (Browning, and ITPCI).

Looks like QMP08J108S OR QMPL08J108S.
Slightly larger overall, but just look at the weight difference. 4.9 lbs vs 8!

 

[whatsnext]

I just looked at the IBI bearing books. Your brg is referred to as a 'light duty pillow block, housing may vary'. The C/R and SKF cross is SY108 . You may be able to find an angular contact ball brg to fit your housings. Tapered rollers need some preload, unlike pillow blocks, so it will be unlikely that you'll be able to 'just fit them in'. Can you post a picture of the brg and the shaft it rides on? I might be able to be a bit more helpful.
John.............

 

[Ekka]

On my Kanga grinder I had to re-machine the cutter wheel shaft to help reduce side thrust. Manufacturer was arrogant and considers me an idiot as they know best, at least it solved some of the problems ... now I have other tree co's getting me to mod their grinders. They voided my warranty, but hey, since these mods nothing's broken ... unlike 3 other people I know with new machines!

When it totally snuffs it I'll redesign the whole shaft/bearing/cutterwheel assy.

Like the other thread my 20hp Dosko went thru 3 sets of bearings in a year, I stopped greasing them ... every now and then I spray CRC or WD40 around the outside of the bearings, mainly to assist with repelling water from the seal, that set has been in for over a year now and there's no sign of grease getting out.

I'd find it hard to believe that taper roller bearings would be efficiently set up in pillow blocks as they need to be up against something more solid usually with preload. Think of your front wheels on a car. Some bearings have dual rollers on an angle but aren't true taper rollers but a fancier self aligning bearing ... this is what my Kanga runs ... but side thrust is still a killer.

Some of the other factors that kill these bearings are the vibration, moisture. On pillow block set ups it's a lot easier for moisture to work at the seals as they're exposed, get into a ritual of spraying them if they're easy to get to.

Think about the thrust bearing on a clutch set up. That's what grinders need. Not rocket sience but if there was a bearing each side of the cutter wheel which took the horizontal force that was adjustable, up against the solid chasis ... problem solved.

Why not email this thread to the manufacturer and let them realise that we are way ahead of them and that their R&D dept needs a swift kick up the behind.

 

[ROLLACOSTA]

vermeer 252 415 hours no new bearings yet ??...i hear all rayco's suffer bearing problem's ..LUMBERJACK is the best guy to talk to about rayco grinder's imo

 

[Dadatwins]

Thanks for the replies and ideas, found that QM bearing place has a distributor in Richmond so I will check them out this week. Sent another email to Rayco expressing my unhappiness with situation, especially since I am looking to buy a larger machine in the near future. Here is an old picture of my current tooth setup. This picture was taken with the first set of bearings on this unit and the seals on them were shot as you can see in the picture. The current set is not that bad but seepage has started and it will not be long for replacement and I want to have a set ready to install when they fail.


http://arboristsite.com/attachment_17908.php

 

[Lumberjack]

The best place to find new bearings is a bearing warehouse. Our here is motion industry. Take the bearing up there and tell them what you want to happen.

Why do you have only 1 green tooth set in the linup?

I am still at a loss as to how its rayco's fault. Bearing problems would be the bearing man. fault, IMO.

We grease our bearings till they puke, works for us, I have forgotten brand and model. I believe we get around 400 hours per set on the RG50.

The preload on tapered bearings could be inside the housing, but there is alot of things that can be wrong thats not Rayco's fault. They have messed up before but they have always made it right for us. The aligment is important with the bearings, there is alot of things that could happen to shorten the life.

Your bearing looks mighty wet, not sure what thats from.

Rayco isnt perfect like you may think I think but I hear too many complaints about the bearings in rayco (not made by rayco) going out fast when we dont have the problems.

What defines when the bearing is worn out? Our method is when the wheel moves side to side some in the cut.

 

[Ekka]

What defines when the bearing is worn out? Our method is when the wheel moves side to side some in the cut.

Perhaps Dadatwins is thinking that when the grease comes out the seals (due to over greasing) the bearings on the way out.

Run'em into the ground till they're noisy or sloppy, you'll know.

I can see from that pic that its clearly an inappropriate application for a pillow block roller bearing to take the kind of side force that it has to.

Whilst the manufacturer doesn't make the bearings they did the design.

 

[Dadatwins]

Why do you have only 1 green tooth set in the linup?

Put green teeth as the lead cutters on wheel. Original setup called for 3 sets of straight teeth and the rest angled. The straights take the most wear so I use green teeth as leads so I can rotate them and get more use. Tried a all gren teeth setup but they were to heavy for this machine and thought that was what blew out the first set of bearings.

I am still at a loss as to how its rayco's fault. Bearing problems would be the bearing man. fault, IMO.

Believe its Rayco fault for putting a light duty ball bearing pillow block on a Stump grinder. Other manufactures used tapered rollers. My dad runs a older 2300 carlton machine and has over 400 hours on bearing, I have heard from Vermeer 252 users that they get 400 - 500 hours out of a set. Talked to a guy at a rental place by me that has same Rayco machine as mine and he is on 3rd bearing set with 500 hours. I believe Rayco to be a superior machine but I think they screwed up with this bearing spec and need to come up with a different replacement. The larger models do not use a ball bearing type, do not why they put them on the small model.

Your bearing looks mighty wet, not sure what thats from.
What defines when the bearing is worn out? Our method is when the wheel moves side to side some in the cut.

This is an old picture with my first set of failed bearing, Understand leaking seals are not a sign of failure. But it is a precursor, since the seals will not hold grease, the bearings will heat up and start stretching out leading to movement. The set in the picture would not hold any grease and were changed also when they started to have movement in the cut.

 

[Stumper]

Ekka, I hear that "grease coming out the seals is a precursor to failure". From more people than just you. I have to smile and shrug. I'm not an authority on bearings. I do know that there are sealed bearings that are truly sealed and their are bearings designed to be greased. Every set of instructions I have ever seen both on equipment and on the PACKAGING OF THE BEARINGS says to grease until grease exits the seals.Some say until CLEAN grease exits the seals. I have run bearings that spun excess grease at start up for YEARS. I don't worry about bearings until they either stop taking grease or develop excessive play.

 

[Dadatwins]

Ekka, I hear that "grease coming out the seals is a precursor to failure". From more people than just you. I have to smile and shrug. I'm not an authority on bearings. I do know that there are sealed bearings that are truly sealed and their are bearings designed to be greased. Every set of instructions I have ever seen both on equipment and on the PACKAGING OF THE BEARINGS says to grease until grease exits the seals.Some say until CLEAN grease exits the seals. I have run bearings that spun excess grease at start up for YEARS. I don't worry about bearings until they either stop taking grease or develop excessive play.

Actually I think I said that, but no matter you are right certain bearings are designed to pack until they run. Most of the bearing except the clutch on a lot of self feed chippers are similar. I am no expert either, but on the Carlton 7500 I run sticker on side of machine reads to purge tapered bearing daily until clean grease is pushed through. That machine has 500 hours on original set, and I grease it daily as it is used. The my rayco 1625a the sealmaster Np-24 are 'supposed' be a sealed bearing and not leak. Of course as they wear and stretch they will start throwing grease. With out grease to cool it down they will stretch and start to get more and more play until they are useless. Especially with the side to side forces being put on a grinding wheel for a stump grinder. My last set in the above picture has oozed for a while and finally threw the seals out with the ball bearings all over a backyard. This current set has just started to ooze so I feel it is only a short matter of time before they fail also. Hopefully I will find a different type of replacement in the bearing house that I plan to visit this week.

 

[Lumberjack]

Maybe that is why I dont understand the problem, we have an RG50 and RG85.

That being said, it would seem to be a design flaw, take the bearing to the warehouse and they should be able to match it.

We grease to purge also.

 

[Beast12]

On our Vermeer SC 252 the bearings at the cutter wheel last around 500 hours. We have almost 600 hours on it now (was built April 2002). I replaced the bearings when I started noticing play in the cutter wheel. I bought new bearings from a local bearing shop and changed them my self. Not a big deal.

The bearings get greased daily (a couple shots) and/or every five hours of stumping per Vermeer's manual. No problems in my experience.

-Matt

 

[juststumps]

dada,,
from lumber jack::Why do you have only 1 green tooth set in the linup?

dada, your post::
Put green teeth as the lead cutters on wheel. Original setup called for 3 sets of straight teeth and the rest angled. The straights take the most wear so I use green teeth as leads so I can rotate them and get more use. Tried a all gren teeth setup but they were to heavy for this machine and thought that was what blew out the first set of bearings.

dada, allthough lumberjack and i disagree on stump grinder needs... he is right about rayco,,it's a good machine...

Tried a all gren teeth setup but they were to heavy for this machine and thought that was what blew out the first set of bearings.

i would give a guess that your bearing problem is being caused by the GREEN TEETH...a 1625, probablly doent have the horse power to pull the extra surface of green teeth through the stump...nor , is it built for them.....my opinion....leaving green teeth as the leading teeth,,,is probablly just as bad....they're doing the cutting...the other teeth are'nt doing anything....i would bet,, if you replaced the bearings,,and went back to the rayco tooth set up... you won't be blowing bearings ...you might not cut as fast... but you probably won't cook your bearings... but this is just my opinion..

PS how do you get the gray box when you cut and paste quotes????

 

[Lumberjack]

dada,,
from lumber jack::Why do you have only 1 green tooth set in the linup?

dada, your post::
Put green teeth as the lead cutters on wheel. Original setup called for 3 sets of straight teeth and the rest angled. The straights take the most wear so I use green teeth as leads so I can rotate them and get more use. Tried a all gren teeth setup but they were to heavy for this machine and thought that was what blew out the first set of bearings.

dada, allthough lumberjack and i disagree on stump grinder needs... he is right about rayco,,it's a good machine...

Tried a all gren teeth setup but they were to heavy for this machine and thought that was what blew out the first set of bearings.

i would give a guess that your bearing problem is being caused by the GREEN TEETH...a 1625, probablly doent have the horse power to pull the extra surface of green teeth through the stump...nor , is it built for them.....my opinion....leaving green teeth as the leading teeth,,,is probablly just as bad....they're doing the cutting...the other teeth are'nt doing anything....i would bet,, if you replaced the bearings,,and went back to the rayco tooth set up... you won't be blowing bearings ...you might not cut as fast... but you probably won't cook your bearings... but this is just my opinion..

PS how do you get the gray box when you cut and paste quotes????

Quote me and look at the tags. Pretty easy. Is what we disagree on is the size of grinder needed (not to get off subject).

I dont think that the teeth are causing the problems, I was just curious. When sweeping through the cut the load on the motor is normally very similar, you load it down to a certain point and hold the swing speed at that point and adjust as it goes through. I cant see how the green teeth can make any noticable difference on bearing life, but I am not a bearing tech.

As I understand bearings the tapered are better for side loads (alot) while they take slightly more power to turn (less efficency). Roller bearings are fine for loads that are inline with the block but rarely for side loads. However if Rayco has made 1000 of these machines without there being more talk about it then I am not sure. I would much rather have tapered over roller in that situation.

As for keeping the bearings outta the dirt, we take no such knit gloves to ours, I am sure life would be increased if we did.