L4200 4wd front axle bearings

[luebb]

Is there any known Kubota advice for a possibility to change the front axle ball bearings #TA140-13140 + #TD030-13150 to cylindrical roller bearings?

 

[Russell King]

Unless there is a thrust bearing somewhere that would cover the axial (along the shaft that the bearings mount on) then the cylindrical roller bearing would NOT work. The cylindrical roller bearing can only handle purely radial load.

 

[luebb]

Not really. There are even locating cylindrical roller bearings on the market like the NUP type that you can combine with NU or N type. Example giving: NUP208-e-xl-tvp2 and NU207-E-XL-TVP2 should easily refit both original bearings mentioned above.
The permissible dynamic axial load of NUP208-e-xl-tvp2 is propably less compared to the original part koyo 6208-4. The permissible radial load on the other hand is extreme. Could be a probate solution for ambitioned loader work.

My Kubota shop specialist is mysteriously talking like there could be cylindrical bearing replacements that Kubota (at least Kubota germany) is officially supporting. Thats why I am asking. I really would like to hear an official statement but Kubota germany ist making a huge secret out of everything just as my shop does. They cant even imagine that there are WSMs out there.

 

[North Idaho Wolfman]

We got into this "talk" years ago.
There is no "proof" that roller bearings will hold up any better than ball bearings.
I have never read or heard of anyone changing them out.

 

[luebb]

My Kubota shop is telling me that they are changing the front axles a real lot from ball to roller bearings. By far the most on municipal mowers because of the heavy mowing decks weighing on the front axle -> instructed by Kubota Germany.
It's really interesting and somehow kind of weird that none of this information is known cross the pond. I think I should dig a bit deeper over here.

 

[Hugo Habicht]

Tapered "cylindrical" roller bearings like the ones used on cars can take axial forces. I would not apply major axial forces on the cylindrical bearings in the picture in your post #3.

See for example https://www.skf.com/group/products/rolling-bearings/roller-bearings/tapered-roller-bearings

Having said that: if the ball bearing is designed correctly there should not be a problem with it.

 

[luebb]

Infact that would be my first idea too an definitly the best solution. But if you use taper roller bearings for the usage as locating roller bearings, you'll need either a double row tapered roller bearing or two matched tapered roller bearings for the changing axial forces. I dont think you can find those with a needed width of 18mm.

 

[JohnDB]

@luebb I hadn't come across axially loadable cylindrical roller bearings until now, interesting proposition. Seems to be a recent design. The information at https://medias.schaeffler.us/en/single-row-cylindrical-roller-bearings-with-cage has a lot of guidance on application. Interestingly axial load can be up to 40% of radial, but its not allowable to have axial withoutout radial load. So I would say its a big risk to use those bearings unless recommended in writing by Kubota.

 

[luebb]

Following your link the minimum radial load to avoid damage is P ＞ C0r/60 , so its P ＞ 53000N/60 for the NUP208-E-TVP2 thats 90Kg respective 200 pound per bearing. That shouldn't be too much for a pendulum axle. Maybe with massive loads without any front weight at the three point hitch.
I think I'll have a talk with my Kubota dealer... trying to dig a bit deeper.

 

[Russell King]

@luebb

Sorry I had not seen that development in cylindrical roller bearings.

There are also ball bearings with ceramic balls in standard sizes. If I recall correctly they will carry much more load (both directions) so mi be able to resolve your issues also, which I understand is just having to change bearings relatively often. How often do they need to be swapped out for new bearings? Have you tried any different greases (I have no recommendations really but they have developed some new types for electric motors that seem to work better).

Thanks for the information!

 

[luebb]

Ceramic is not an option. Super high rpm, no corrosion, good wear resistance but a poor load capacity. They are less tough and more brittle. Steal is way better especially for heavy loads and impacts.
Basically I'm not asking because of many changes needed or something. Actually one bearing broke and as a industrial mechanic teacher I was just talking with my Kubota dealer about it. Improvements are always interesting. That's all.